Webinar #3 – Loss of SynGAP function in the striatum leads to altered motor & habit learning

Here are our introductory comments:

We are very excited to continue the SRF webinar series. The goals of the series are:

• getting you closer to the science 
• making you aware of the research that is been done and the opportunities to participate
• and empowering your communications with clinicians 

Today’s speaker is Dr. Helen Bateup she is Assistant Professor of Neurobiology at UC Berkeley where she has been conducting research since 2013. She earned her PhD at Rockefeller University and her post-graduate work was done at Harvard Medical School with Dr. Bernardo Sabatini. It was there while she was studying the mTOR signaling pathway that she became interested in genetic mutations which affect synaptic function and plasticity and lead to the phenotypes of various neurodevelopmental disorders and ASD.

Her lab describes one of its main focuses as “Understanding the molecular machinery that allows neurons to both be dynamic and maintain balance”. This is done through a multi-faceted approach which includes characterization of both mouse and human cells in various diseases. 

One of the main disorders she has studied so far is Tuberous Sclerosis Complex and her lab has identified some synaptic changes which they believe may lead to the rigidity in behavior and learning that are seen in TSC mouse models. She also was part of a collaboration which used CRISPR technologies to create organoids which allowed her team to better replicate certain aspects of TSC which the mouse models were not able to.

Over the years she became interested in SynGAP1 mutations as their connection to autism spectrum disorders became apparent. The preliminary work in her lab suggests that loss of Syngap1 from striatal neurons is likely to alter their function and may be an important contributor to the repetitive, restricted and inflexible behaviors observed in SYNGAP1 disorder.

My greatest memory of her was the several hours she spent with us when we visited her lab last year – she described the activities and experiments she was doing with the mice with so much care and attention, and was keenly interested in whether and what analogous behaviors we also saw in our Syngapians.

THIS IS FOR TRANSCRIPT ONLY:

0:05Great should we jump in? Yes let’s do it. Ashley  and I met Dr Bateup at a conference forever ago  

0:14after we became aware of her I’ll let you cover  it all in the introduction and she was gracious   enough to have us give us a tour of her lab and  she’s lovely and we’re just so excited to hear  

0:23from her and let parents know about her and  you know let people become aware of the growing  

0:31number of scientists that are that are working  in this space and so thank you for making time   Dr Bateup thank you for organizing all of this  Sydney and thank you to everybody else who’s here  

0:41got some really great parents on this call  and a few new friends so looking forward to it

0:48all right well we’re very excited to continue our  SRF webinar series with Dr Bateup today obviously  Introduction to the work of Dr Helen Bateup

0:54the goals of our series are to get you closer  to the science, to make you aware of research and   opportunities to participate, and to empower your  communication with your clinicians. So we want to  

1:04give you a little plug for our next webinar in  the series which is going to be on august 3rd at   12 EST that’s going to be with Dr. Elizabeth heller  and her work on epigenetics and gene regulation so  

1:15as you may know SynGAP Research Fund is currently  fundraising for a grant which allow which would   allow dr Heller to bring your expertise on  these topics to the sphere of SYNGAP1 research  

1:24so again that’s going to be august 3rd at 12  eastern time so today’s speaker is dr Helen Bateup  

1:31she is the assistant professor of neurobiology at  UC Berkeley where she’s been conducting research   since 2013. She earned her phd at rockefeller  university and her postgraduate work was done  

1:42at harvard medical school with dr bernardo  sabatini it was there while she was studying the  

1:47mTOR signaling pathway that she became interested  in genetic mutations which affects synaptic  

1:52function and plasticity and lead to the phenotypes  of various neurodevelopmental disorders and ASD  

1:59her lab describes one of its main focuses as  understanding the molecular machinery that   allows neurons to be both dynamic and maintain  balance this is done through a multi-faceted  

2:09approach which includes characterization of  both mouse and human cells in various diseases  

2:14one of the main disorders she has studied so  far is Tuberous Sclerosis Complex (TSC) and her lab   has identified some synaptic changes which they  believe may lead to the rigidity and behavior and  

2:23learning better seen in the TSC mouse models she  was also part of a collaboration which used CRISPR   technologies to create organoids which allowed her  team to better replicate certain aspects of TSC  

2:34which the mouse models were not able to. Over the  years she became interested in Syngap mutations  

2:40as their connection to the ASD became apparent.  The preliminary work in her lab suggests that  

2:45loss of SYNGAP1 from the striatal neurons  is likely to alter their function and may   be an important contributor to the repetitive,  restricted, and inflexible behaviors observed  

2:54in SYNGAP1 disorder and then of course  as Mike mentioned he and Ashley were able to  

3:00visit her lab and this is what Ashley had to say  about Dr Bateup. She says: my greatest memory of her  

3:06was the several hours she spent with us when  we visited her lab last year she described   the activity as an experiment she was doing with  the mice with so much care and attention and was  

3:14keenly interested in whether and what analogous  behaviors we also saw in our Syngapians so we  

3:19now have the pleasure of turning things over to Dr  Bateup whose talk today is titled “Loss of SynGAP  

3:25function in the striatum leads to altered motor  and habit learning”. Dr. Bateup over to you.  

3:33okay thank you so much it’s a pleasure to be  here with you and tell you a little bit about  

3:38some of our work our ongoing project looking at  Syngap I’m excited that I do have some kind of  

3:44fresh off hot off the press data to share with you  about our early findings of how SYNGAP1 affects  

3:51the function of this brain region called the  striatum and I’ll tell you a bit more about that   so I think let’s see am I able to share my screen  i think i might need to get permission for that

4:10all right can everyone see that  those slides okay and let’s see if  

4:15okay perfect okay so again thank you so much for  having me it’s a pleasure to be here and i’ll  Overview of talk

4:20try to not give too long of a talk because  i would love to have questions and discussions  

4:26and hear your thoughts and get your opinions so  all right so just a very quick kind of overview  

4:33this is a just a schematic that kind of generally  shows what my lab is interested in understanding  

4:39so we are neuroscientists and our kind of main  areas to try to understand the basic biology of  

4:47kind of how the brain works at the broadest  level and so we’re interested in starting down  

4:52from genetic and molecular level to understanding  how genes and molecular pathways actually affect  

4:59the structure and function of brain cells called  neurons and of course we’re very interested in   understanding how these neurons communicate  through synaptic connections and ultimately  

5:09how this synaptic activity drives changes in the  activity of neural networks that ultimately affect  

5:16our cognition our behavior our thoughts and  our actions so this is our kind of general  

5:21goal of what we would like to understand and  we are particularly interested in understanding  

5:27how kind of this process or these pathways go  wrong in states of disease and to study this we  

5:34have been focused on genetic disorders because  i think this is a reasonable starting point if  

5:40we know the genes that are mutated that gives us a  tractable system to begin to decipher kind of this  

5:47black box of how these genes or how disruption  of these genes affect molecular pathways neuronal  

5:53function the connections and communication  between neurons etc and ultimately how  

5:59these changes at the cellular molecular level  or circuit level will lead to a disease state  

6:05and so this has kind of been the model for how we  address these questions in the lab all right and  

6:13yeah so in our lab we do experiments at multiple  levels again all the way from molecular to the  

6:18function of individual brain cells all the  way up to the function of neural circuits.  Molecular pathways implicated in neurodevelopmental disorders

6:25Okay so where do we start in terms of kind of  which genes or which disorders do we tackle   and i’ve been interested for some time in  neurodevelopmental disorders in particular  

6:37Autism Spectrum Disorders and so this is just   kind of an overly complicated schematic that  shows an image of a synapse which is the  

6:48connection point between two neurons across which  neurotransmitter is released and it shows you a  

6:56subset of the proteins that are involved in this  synaptic transmission or synaptic communication  

7:03and the point here is that it’s complex that  there are many proteins that need to work  

7:08together in a coordinated way to enable proper  synaptic communication which is kind of the  

7:14fundamental basis of how our brain works and so  what this image shows is some of these proteins  

7:22and then in this orange color are proteins  whose genes have been shown to be mutated  

7:29in certain forms of Autism Spectrum Disorder or  or related neurodevelopmental disorders so you  

7:34can see kind of one theme that has emerged  is that a lot of these genes encode proteins   that function at the synapse even though their  specific biological activity is fairly diverse  

7:45and so these are kind of the genes and the  proteins that we are really interested in studying   of course there’s many so we have to kind of  choose where to start and so Sydney and Mike  

7:56mentioned my lab has been so far primarily focused  on one of these genes or two of these genes here  

8:02which are called TSC1 and TSC2 and i’ll tell you  very briefly a little bit about that but  

8:09really we started by looking at TSC but then we  were interested to know if what we found in terms  

8:16of how tsc mutations affect synapses and affect  behavior could be relatable to these other autism  

8:24risk disorder genes and so we’ve recently  expanded to looking at other genes and   as mike said i attended a Syngap conference  a couple of years ago and got really kind of  

8:32interested and excited about Syngap in  terms of its interesting functions and  

8:39there i think are some key similarities  in um Syngap disorder that are kind of  

8:46also seen for tsc so i thought we might have some  knowledge that we could share to dive into this so  

8:52um just very quickly again because most of our  work has been on tsc i just want to tell you a   little bit about that um and i’m happy to answer  questions about rtsc work so basically tsd stands  

9:04for tuberous sclerosis complex and it’s caused by  mutations in these genes which are tse1 or tsc2  

9:11and the protein products of these genes form a  complex that regulates a signaling pathway called  

9:16mtor and i won’t go into that too much today  um it’s a rare disorder but it’s not completely  

9:23uncommon it’s a syndromic disorder so there  are medical concerns specifically with benign  

9:30tumors that can occur in different organs but  the neurological and psychiatric aspects of tsc  

9:36are often the most burdensome for patients and  caregivers and so these range from these physical  

9:43malformations in the brain that happen  during embryonic development which are   called tubers or cortical tubers this  is where the disease gets gets its name  

9:53and then there’s a lot of overlap i think with  some of the aspects of syngap1 disorders which  

10:00include very high rates of epilepsy which is  has childhood onset can often be intractable  

10:06there’s varying degrees of intellectual  disability and there’s a very high prevalence  

10:11of autism spectrum disorder about 50 of  tsc patients receive an autism diagnosis  

10:17and many others have kind of behavioral signs of  autism but there’s also quite a number of other  

10:25psychiatric and behavioral conditions that are  frequently seen in tse individuals and so again  

10:31my lab has been very interested in understanding  how this mutation and alteration in this pathway  

10:36affect neuronal and synaptic function to lead to  this kind of constellation of of psychiatric um  

10:43and behavioral challenges and one thing that’s  kind of been um focused on or or come to the  Tuberous Sclerosis-Associated Neuropsychiatric Disorders (“TAND”)

10:50forefront recently and i showed this slide to  mike and ashley and when they visited my lab   and we’re kind of looking at some of these  shared things so this is in tsc and this  

10:59is supposed to be kind of an umbrella that’s  showing these um plethora of psychiatric and  

11:06behavioral challenges that individuals with tsc  face and again i think many of these may also  

11:13be seen in individuals with sin gap as well  and so this is just to show that there are   a number of behavioral problems like aggression  inattention impulsivity repetitive behavior sleep  

11:24problems um psychiatric diagnoses like autism  adhd and mood disorders and then there are also  

11:32kind of cognitive specific cognitive deficits or  problems with cognitive flexibility and so these  

11:39aspects of tsc have been kind of understudied most  researchers had focused on the epilepsy which is  

11:44a major problem and so my lab kind of we were  interested in tackling where do these behavioral  

11:51and psychiatric problems come from and could we  identify kind of the cellular molecular circuit   basis for these and so i’ll just um sorry  before i get into that i’ll just highlight  

12:01i guess one um of these aspects which is autism  which encompasses kind of an several different  

12:08behavioral challenges and so i imagine many  of you are aware of this this is just showing  Diagnostic criteria for autism spectrum disorder (ASD)

12:14the diagnostic criteria for autism so what  most people think of are these um social  

12:20impairments which are impairments in  social communication and interaction  

12:25but the second main diagnostic criteria for  asd are these restricted repetitive patterns  

12:30of behavior interests and these i think have been  perhaps a little bit less studied in the autism  

12:37research fields but they include things like um  simple motor stereotypes repetitive movements but  

12:45then they can be kind of more complex repetitive  restrictive behaviors like insistence on sameness  

12:50or inflexibility or strong adherence to routines  or rituals and these can be fairly intense and  

12:58in terms of highly fixated on specific objects  or specific activities and so this is something  

13:04that’s very much seen in individuals with tsc  and as far as i’ve kind of understood also   prevalence in in kids with with sin gap disorder  and so we thought we were interested in tackling  

13:15specifically this aspect and trying to understand  where these behavioral changes are coming fromChanges in basal ganglia function may be central to ASD & TAND

13:23and so what we thought of is that maybe these  behavioral changes or these kind of more motor  

13:31aspects of autism could be driven by changes in  this brain structure or this brain circuit called  

13:38the basal ganglia and so this is a kind of image  a schematic image of a slice through a mouse brain  

13:46but um human brain has the same structures in the  same circuits and these are kind of the main brain  

13:53regions that are within the basal ganglia and  it’s you can see fairly complex circuits which   i won’t go into too much but the job of this of  these brain regions and these brain circuits are  

14:03to help you decide which actions to take in  a given circumstance so to kind of understand  

14:10the context and the environment and choose the  appropriate action or the appropriate response  

14:15and then another thing that this brain region  does is help you kind of learn motor routines  

14:21or motor habits so if you kind of repeatedly  do the same action over and over which might be  

14:27like driving to work for example at first  you have to use a lot of conscious cognitive  

14:33control to kind of navigate the streets or look  at your map and get you to where you want to go  

14:38but eventually if you do that action or that  activity over and over it can become habitual  

14:43we call it and so you can drive to work um without  thinking too much about it without using too much  

14:49kind of cognitive resources it becomes kind of a  motor pattern and this can be advantageous it can  

14:55help make things more efficient but it can also  be problematic if it becomes pathological in that  

15:02the over-reliance or the over-development of motor  habits could lead to things like compulsions um or  

15:08even an addiction and so we thought that maybe um  changes in kind of the way this brain region kind  

15:16of learns these motor habits might be involved  in these repetitive restricted behaviors and then  

15:22the stratum is also important for allowing you to  have behavioral flexibility again to kind of adapt  

15:29your behavior adapt your decisions and actions  based on kind of changing environmental demands  

15:35and problems with the ability to do that can lead  to inflexible behaviors and so these are what  

15:41this brain region normally does and it carries  out these actions by altering the strength of  

15:48these synaptic connections between neurons and so  that’s where our focus was so again the idea was  

15:54that mutations in these genes that cause autism  and other related neurodevelopmental disorders  

15:59are altering kind of the synaptic communication in  these brain regions and circuits in a way that’s  

16:06facilitating the formation of fixed motor routines  and habits and at the same time maybe reducing  

16:11the ability to be flexible and so  this was what we wanted to investigate  Major cell types of the basal ganglia

16:17and so i’ll try not to overwhelm too many details  about these cells in these circuits but there’s  

16:23just a couple of things to know so this um again  this is a mouse brain and these are images from a  

16:30mouse brain and in red we can see with a red  fluorescent blue protein the striatal cells  

16:36are highlighted and the striatum is this large  brain region here that’s really kind of the input  

16:41center for this structure where a lot of these and  synaptic plasticity and learning is happening and  

16:47there are actually two types of stratal neurons  and they project to different downstream brain  

16:54regions so here are these circuits and kind of the  coordinated activity of these two cell types is  

17:01important for motor learning and habit formation  and so we are interested in looking at these  

17:08particular cells and we’ve also been interested in  the context of tsc at looking at these other types  

17:14of neurons called dopamine neurons which modulate  the activity of these other cells so these are the  

17:19the key cells we’ve been interested in to  understand whether these mutations affect their  

17:24synaptic function and activity and here just very  briefly i’m not going to go into our work on tsc  

17:31because as i said we have now some new data on syn  gap that might be more of interest but just to put  

17:37up a couple of the references for papers if you’re  interested that we published on tsc basically what  

17:45we found or i should say these are the postdocs  and graduate students in my lab who found who  

17:50worked on this we have found that mutations in  tse affect the activity of these striatal neurons  

17:58and that this leads to increased um learning of  a fixed motor routine which again we think could  

18:06result in the development of kind  of repetitive restricted behaviors   and we’ve also found that this tsc  mutation affects these dopamine  

18:14neurons which modulate the activity of these cells  and when tsc is disrupted in these cells it leads  

18:20to behavioral inflexibility or perseveration  and so we do see that changes in these cells  

18:30do drive behaviors that may be relevant for these  restricted repetitive and flexible behaviors  

18:36and so based on this work we wanted to explore the  possibility about whether other autism-risk genes  

18:45or other genes involved in neurodevelopmental  disorders might do something similar   and so that’s where we started this project  again um just a couple of years ago that’s led by  

18:54project scientist julian who mike and ashley have  met and we got really interested in syngap and  

19:02wanted to understand whether alterations in  sin gap function might lead to some of the same  

19:07behavioral and synaptic changes and one of the  reasons we were excited about looking at syngap  

19:14first in really nice work of course from rickey  near’s lab and gavin remba has clearly established  Syngap1 is highly expressed in the striatum

19:20that syngap is a very important synaptic protein  and we are interested in looking at synapses and  

19:28i would say the majority of the work so far has  focused on syngap function in the cortex and  

19:33hippocampus and how alterations in synapses there  might lead to impaired intellectual ability or  

19:42altered learning um or possibly even epilepsy but  if you look at this this is a pretty relatively  

19:49old study that looked at the expression patterns  of syngap in the mouse brain you can see that in  

19:55addition to the cortex which are blue which means  that they have high levels of syngap expression  

20:00you can also see very high levels of syngap  expression in this brain structure here which is   which is the striatum which is the one i just  introduced you to so we were excited about this  

20:10that syngap is highly expressed in the stratum  and there’s a recent study that just came out from  

20:16alex bay’s lab where they looked at the expression  of syngap protein in these different brain regions  

20:23across different developmental times and just  this is just to show you that the striatum is here  

20:29this is hippocampus and cortex so you can  see that syngap protein really is strongly   expressed in striatum and shows kind of these  similar developmental dynamics as it does in  

20:39these other brain regions so we are excited to  investigate what is the function of syn gap in  

20:44these striatal neurons and could alterations in  these striatal neurons be contributing to some of   the behavioral changes in individuals with same  gap okay so we had a look at this in terms of  Syngap1 is expressed in both direct and indirect pathway cells

20:57syngap expression in our own lab and so this  again is a section of a mouse brain and this  

21:03is just a wild tape normal mouse and in green we  are looking at the mrna levels of syngap1 and so  

21:12again you can see very strong expression here in  the cortex hippocampus but also in this striatum  

21:19and i mentioned previously that there are  two different types of striatal neurons that   kind of differentially control behavior  and these two cell types can be  

21:28distinguished by the fact that one type expresses  a certain type of dopamine receptor d1 and the  

21:34other type expresses a different dopamine receptor  d2 and so we saw that syngap1 was expressed in  

21:40both types of these striatal cells and that’s  quantified here so the vast majority of these  

21:47d1 or direct pathway type cells and d2  or indirect pathway type cells express  

21:52n-gap so again i think a relevance to study how  alterations in cinep would affect these cellsSyngap1 mouse models

22:01okay so in order to study this we needed   mouse models where we can manipulate  the expression of syngap1 to understand  

22:09what happens and so we were very lucky to get in  touch with gavin rumba who very kindly sent us  

22:17the mouse models he’s generated for studying  syngap and so what we have in the lab now is a  

22:24really nice full panel of genetic mouse models so  we have these syngap mice which are heterozygous  

22:32and which have essentially syngap1 haploin  sufficiency in all cells and this is thought to be  

22:39kind of perhaps most relevant to what might  happen in an individualist and gap disorder  

22:45but to kind of further drill down on  which cell types are responsible for  

22:51disease-related phenotypes we also have these  conditional knockout mice in which syngap1 is only  

22:59disrupted in a specific cell type and i won’t go  into the details of how we generate these animals  

23:04but i’m happy to answer questions but basically  we have mice that just have disrupted one or two   copies of syngap1 only in these direct pathway  striatal cells or only in these indirect pathways  

23:17striatal cells and the rest of the brain and body  um have normal syn gap expression and so these  

23:22mice allow us to test whether these particular  cells are responsible for any specific behavior  

23:28changes and i’ll show you i’m going to show you  some preliminary data from each of these models  

23:36okay so first we have um i should say that  this is very much still a work in progress  

23:42so none of this is published yet and a lot of  this data was actually obtained quite recently so   we’re still working on this but i just want  to share kind of a few bits of data that we’ve  

23:51gathered so far that i think look interesting so  one other thing one of the behavioral phenotypes  

23:57that has been previously observed in these mice  with global affluence efficiency of syngap1 is  

24:04this hyperactivity in when the mice are placed in  an open arena so they we just place the mice in an  

24:11open empty box essentially and record their  activity over some amount of time and we see  

24:16how much they move around and so this is  a very basic behavior characterization and   you can see these mice that have loss of  one copy of singaporeans show this pretty  

24:27profound hyperactivity meaning they’re running  around a lot more when placed in this open arena  

24:34and we were interested in wondering if alterations  in these striatal cells might be responsible  

24:41and so we looked in these again these cell type  specific mice where again syngap1 is only altered  

24:47in a particular cell tape and interestingly we  didn’t really see um any hyperactivity when we  

24:54disrupted syngap1 in these direct pathway striatal  cells or really in these indirect pathway striatal  

25:01cells although there was maybe a small change  in these knockout animals so this suggests that  

25:07this particular behavior phenotype in the SYNGAP1  haploinsufficient mice is not likely to be driven  

25:14or can’t be sufficiently caused by changes in  the striatum okay so that’s that’s one thing  

25:21um so that’s a little bit of negative data but i  think it helps us interpret our subsequent data  

25:28so that’s just basic activity what about more  specific aspects of motor function and so one  Syngap1 +/- mice exhibit altered motor performance

25:36pretty easy thing easy test we can do in mice  is we can measure their motor coordination and  

25:44we can measure their motor learning and so  the way we do that is kind of a little bit  

25:50of a strange test where we put these mice on this  rotating treadmill and that’s called a rotor rod  

25:57and what we do is we first start this  treadmill rotating at a relatively low speed  

26:03and the mice have to walk  along the treadmill to keep up   and what we do is we do multiple trials so we put  them on the this rotating treadmill for about five  

26:14minutes at a time and we measure basically  um how long they can stay on this rod before  

26:22they start to lose coordination and we slowly  increase the acceleration over the five minutes  

26:29and so the length of time these mice can kind of  perform this task is a measure initially of their  

26:35motor coordination but then after multiple days of  multiple trials it becomes a learning test where  

26:41the mice will get better and better at this  naturally so their motor performance improves  

26:46and this motor learning is thought to be due to  plus synaptic plasticity within these striatal  

26:54cells that i’ve been talking about and so how do  the SYNGAP1 mice perform on this test well what we  

27:02found so here are showing the performance of these  animals across these multiple trials and this is  

27:10essentially their their performance and  you can see in grey or silver are the  

27:16wild type or normal animals that have normal  SynGAP expression and they have this initial  

27:22mode of performance and then basically each  day they get better and better until they can  

27:28perform quite well in this test and what we  found is that these mice that have lost one  

27:33copy of SYNGAP1 they have actually um slightly  reduced initial performance in this test  

27:40which means that they had some slight  impairment in their motor coordination  

27:45and they don’t really catch up or they don’t  really learn as well as their um as the  

27:52wild type litter meats that have normal  synthetic one expression so this is a   relatively subtle phenotype but clearly shows  that these animals have reduced motor coordination  

28:02and perhaps reduced ability for motor learning  and i think that kind of fits with some of the  

28:08from some of the findings in individuals within  gap of potentially impaired motor function or or  

28:14motor developmental delay okay so what about these  mice that have disruption of SYNGAP1 just in these  Loss of Syngap1 in indirect pathway neurons impairs motor learning

28:23striatal cells so interestingly when we look at  mice that only have SYNGAP1 disrupted either one  

28:30copy which is heterozygous mice or both copies  disrupted which are these knockout mice and  

28:36compare them to their wild tape siblings all of  these mice perform essentially the same suggesting  

28:43that loss of sin gap 1 from this this particular  cell tape doesn’t impact this behavior performance  

28:50however this is where things started to get pretty  interesting if we just disrupt SYNGAP1 expression  

28:56from these indirect pathway striatal cells now we  can see that both the heterozygous in light blue  

29:04and these homozygous knockout and dark blue  animals perform worse at this task compared to  

29:11their siblings and so again they have these mice  have reduced initial motor performance slightly  

29:18and they show reduced learning across they  can learn they do improve with this task  

29:24but they never reach the performance of their  wild-type counterparts and so this is pretty  

29:30interesting this suggests that just disrupting  SYNGAP1 in these specific cells which are again  

29:37one population of striatal cells is sufficient to  fully um recapitulate this motor coordination and  

29:43motor learning impairments and so i think this is  helpful for us um to understand that these cells  

29:51might be kind of the origin of this impairment and  if we were interested in potentially treating it  

29:57we would want to potentially try to adjust  the activity of these cells and that might be  

30:02sufficient to help improve motor coordination and  learning okay all right so this was I think some  

30:10compelling evidence that the striatum is involved  in at least some of the behavior phenotypes in the  

30:17Syngap mice and that in particular these indirect  pathway cells might be particularly relevant  

30:25okay so those were some basic motor function  motor coordination but we were interested in  

30:31getting back to this question of whether these  kind of restricted repetitive inflexible behaviors  

30:38are due to alterations and the ability to learn  and form motor habits and there’s actually a  

30:46pretty nice way we can test this in mice and so  i’ll just walk you through this behavior test  

30:54that we did to try to assess this and then please  let me know if you have questions about this so  

30:59the way we can test kind of habit formation in a  mouse is to train them on this lever pressing task  

31:07so we have a behavior box that has these levers  that are designed for mice and the mice are  

31:16a little bit hungry so they are motivated to  look for food and what we do is we give them a  

31:22few sessions to learn that if they press this  lever they will get a food pellet as a reward  

31:28and at first the mice are a little bit confused  and it takes them a little while to understand   this but eventually after multiple trials after  multiple exposure the mice learn that if they  

31:38press this lever they’ll get the reward so we  train this mice on this test and we make it  

31:44more and more challenging over time  where they have to press the lever   more and more times to receive their award and so  normal mice will learn this task and i’ll show you  

31:53that data in a second and we’ll learn to press the  lever for their food reward and then what we do  

32:01is we do this so-called um devaluation test so  after the mice have been trained and have learned  

32:07to do this we test whether they are pressing  this lever in a gold so-called goal-directed way  

32:16or whether they’re just pressing this lever kind  of out of habit and the way we can do this is we  

32:22essentially before the test we give the mice  access to the reward right so we just give  

32:29them the food pellets in their cage right and so  they can eat these food pellets and they should be  

32:35fully stated and they should not be hungry and  they should not be particularly interested in   pressing the lever anymore because they just got  all the food pellets they want and so that what  

32:44we do then is put them back in the box just for a  few minutes and see how much they press the lever  

32:49and if the mice were pressing the lever because  they are trying to get this goal which is the   food reward they will not press very much if  they’ve just had access to that food reward  

32:58right so why would they bother they’re not  really interested in the food and so we see  

33:04this decrease in lever pressing once this reward  has been devalued alternatively we um do a control  

33:13where we give them access to something else and we  put them back in the box and if again they should  

33:19still in that situation still be interested in  pressing the lever to get the food so in response  

33:24to the control they will still press the lever but  in response to this um devaluation they will not  

33:30and if this if this pattern is true then these  mice are goal directed meaning they’re going in to  

33:35do this task in a goal-directed way and it’s known  that this kind of goal-directed strategy is fairly  

33:41flexible such that if the um testing conditions or  the environment change then the mice would adapt  

33:48to achieve a new goal okay and this is how we  we operate um every day when we make decisions  

33:53um and and choose our actions however if the  mice are doing this out of habit meaning that  

33:58they just see the lever and because they’ve been  pressing the lever so much they just go ahead and   press anyway without really consciously thinking  about it or without you know consciously trying  

34:07to obtain a specific goal then they will press  the lever just as much on the control day and  

34:13the food day so even though they’ve just gotten  all this food pellet reward they’re still just   going to go ahead and press the lever and that’s  how we can that’s how we test this in mice okay  

34:24hopefully that was clear um so here are our  results so that was supposed to be animated okay  Syngap1 +/- mice show impaired goal-directed behavior

34:31so here are again these mice that have  global haploinsufficiency of SYNGAP1 so again  

34:38loss of one copy of SYNGAP1 in every cell and this  is what their performance looks like in this task  

34:44this is how much they’re pressing the lever  which is we use that as a measure of how well  

34:49they’re learning and these are trials which is  basically each day and they go in for about an  

34:55hour into the little box each day so  you can see initially the mice press   very little because they don’t quite understand  that pressing the lever gets them food  

35:04but after some point they beginning to they  begin to press the lever and they begin to know   that they can earn food this way there we go and  then we start making it more and more challenging  

35:14here and i won’t the details of these numbers  don’t really matter but you can see the   these are the control mates they start pressing  more and more to earn their reward and so  

35:23they’re learning this task and interestingly  these mice with loss of one copy of Syngap  

35:28um they don’t show initial kind of difference  in their level pressing behavior but they  

35:35at some point become start to press the lever many  more times than their um wild type counterparts  

35:42and um it’s possible that this could be kind of  due to their hyperactivity but we actually don’t  

35:48think so we think it might be something else and  we um it might be something with their motivation  

35:54to learn um this is something we’re still trying  to figure out so they’re not impaired in their   ability to learn this task if anything they  learn it much better or much more robustly  

36:05but this is where the interesting thing comes so  after they do this they learn this task we do this  

36:13value devaluation testing okay and so here are  the control animals in gray and what you can see  

36:21is that this is the performance of the mouse  on the d-value day basically how much did it  

36:27press the lever and again it shouldn’t press the  lever very much because it’s not hungry and it’s  

36:32not interested in earning a reward and here on the  value day it should press the lever a lot because   it’s still interested in getting the reward and so  you can see all of these control mice are what we  

36:42would call goal directed meaning they show very  different performance under these two conditions  

36:48however here are the mice with loss of SYNGAP1 and  you can see first of all there’s huge variability  

36:55so the individual mice are kind of all over the  place let’s say in terms of their performance  

37:01but they certainly are not showing this consistent  goal directed behavior in fact some of these mice   are pressing more during the devalue day than the  value day which is essentially kind of opposite  

37:10of what we might expect or opposite of what this  normal performance is and then this is just kind  

37:16of another way to show this data that shows the  devaluation index so the higher the score the  

37:22more goal directed the mice are and the if the  score is negative they’re more habitual or less  

37:28goal directed and you can see again there’s a much  wider spread for these um Syngap mice and so this  

37:35suggests that um these mice have really altered  ability to purdue this goal-directed action and  

37:43maybe at least some of these animals doing this  behavior in a much more habitual way okay so this  

37:50was pretty interesting um to see so how about the  mice where we just delete SYNGAP1 from striatal  

37:57cells and this is again still in progress so we’ve  only done this for these indirect pathway cells  

38:05and what we find is something strikingly similar  so here are the lever presses during learning  Loss of Syngap1 from indirect pathway cells disrupts goal-directed behavior

38:11again these are the control animals this is a  completely different set of mice now and these  

38:16are mice with loss of SYNGAP1 just in these  indirect pathway cells only and they have the  

38:22same um kind of increased lever pressed behavior  that emerges over time um and again remember  

38:29these particular mice were not hyperactive and  so again we think there’s another reason they  

38:34may be kind of really vigorously pressing the  lever in this task that we we need to figure out  

38:40and again strikingly similar to those  um kind of global heterozygous animals  

38:47these mice with loss of one copy of syngap just  in indirect pathway cells also show this really  

38:53varied response on this devaluation testing  again the wild type animals all show this  

38:59very clear goal directed behavior where they’re  suppressing their lever pressing where they’re   suppressing the lever pressing under devalued  conditions um and the syngap mice again have wide  

39:10variability with some mice again pressing more  even during devalue day suggesting that they  

39:17are doing this behavior um kind of in a very  different way or for very different reasons  

39:24than control animals would and again this is still  fairly preliminary data so we’re still trying to  

39:30kind of understand um where this is coming from i  will say that we tested both male and females mice  

39:38and it’s not um due to a sex difference it’s not  that the females perform one way the males perform  

39:43another way so we need to work to understand  this variability but clearly these animals   are doing something different than the controls  okay and again these indirect pathway striatal  

39:54cells may be really the most relevant cell type  and the and disruption of syngap in these cells  

40:00seems to be disrupting this kind of flexible goal  directed behavior okay and so very last thing  How does loss of Syngap1 affect striatal cellular function?

40:08i’ll just share with you so we’ve been looking  at these behaviors and we think there’s some  

40:14quite interesting things here and so what’s  happening at the cellular level and so you may  

40:20have likely heard in other talks that um syngap  is is a synaptic protein although may have other  

40:25functions to be uncovered um but certainly it’s  very um highly expressed at synapses and these  

40:31striatal neurons um have these dendritic spines um  which you can see so here’s a striatal neuron from  

40:39oops sorry that’s supposed to be a wild type this  a wild type animal and here are these dendrites  

40:44um and here these little protuberances are the  dendritic spines which is where the synapses  

40:50are formed and we can look at the number of  these and the size of them to get a sense of  

40:56synaptic function and so here is what one of these  spines looks like in a normal striatal cell and  

41:02here is a cell from the SYNGAP1 heterozygous  mice and this is one of these indirect pathway  

41:08cells you can see the cells overall are  fairly normal they look pretty similar   but if you look closely at these spines um it does  look different right so what you can see is that  

41:19these spines appear larger the individual  spines are bigger and perhaps less dense  

41:25and so we can actually quantify that again this  is still fairly preliminary data but similar to  Loss of Syngap1 increases dendritic spine size and reduces synapse density

41:32what people have seen in other brain regions  loss of SYNGAP1 seems to increase the size of  

41:39these dendritic spines which again are a proxy  for the strength of the synaptic connections  

41:46this is kind of a more subtle effect but we  clearly see also a reduction in the number of   these spines um or the density of these spines  which is a proxy for the number of synapses  

41:57and again these are the in these  indirect pathway cells which we see   are really driving some of the behavior phenotypes  so this is um just kind of a little preliminary  

42:08evidence that indeed sin loss of sin gap is  affecting the structure and number of these  

42:14spines and is likely going to affect synaptic  properties and synaptic plasticity and that’s what  

42:20we’re working on now we’re gearing up  to do a lot of experiments to understand   how synapses might be altered in these  cells because that’s going to be important  

42:29for us to understand how this these cells are  affecting behavior okay so um i will stop there  Summary

42:36i’ll just quickly summarize so what we’ve found  so far again this is very much a work in progress   is that SYNGAP1 is certainly highly expressed  in this brain region called the stratum in both  

42:47types of these um striatal cells and that loss of  SYNGAP1 in these cells does appear to affect their  

42:55dendritic spine and number and we expect that  there will be effects on synaptic communication  

43:01that we’re very interested in pursuing and that  these mice um with global loss of syngap they do  

43:09exhibit hyperactivity impaired motor coordination  impaired motor routine learning and what looks  

43:15like reduced goal directed behavior which we  think are relevant mouse behavior phenotypes  

43:20that might provide some insight into behavior  changes in individuals with syngap mutations  

43:26and we’ve pinpointed this particular type of  striatal cell that seems to be sufficient to  

43:32cause some of these behavior changes and that  we’re very much interested in pursuing further  

43:38and so very quickly um kind of what we’re  doing now and in the future so i think there’s   a lot of other behaviors that would be very  interesting to look at um kind of looking at the  

43:48clinical summaries of of what types of problematic  behaviors individuals have i think things like  

43:54impulsivity problems with attention problems  with flexibility and maybe even more simple motor  

44:01parameters like gait are things that we can look  at in mice and we are interested in doing that  

44:06we have a lot of work to do to understand um more  about the cellular function including synaptic  

44:12changes um and then if we can you know once we’ve  established these uh phenotypes at the cellular  

44:18and behavior level then um we’d really like to see  if these can be improved right so the whole goal  

44:24is if we understand which cell types are important  what changes are happening in those cell types we   would have a better idea about what we could do  to treat these behavioral conditions and so we’re  

44:34pursuing a couple of approaches one is to use  these um genetic restoration mouse model that  

44:41Gavin Rumbaugh has developed to see if we restore  Syngap expression in striatum does that restore  

44:47behavior and then looking to the future you know  could we use an um even more sophisticated kind  

44:54of genetic rescue strategy to improve some of  these phenotypes that could be given to mice  

45:01even after they’ve developed problems and so  this is something that’s fairly far off that  

45:06we haven’t really started with yet but i think  is um where where we’re going in the future  

45:13okay so um i’ll stop there and just  quickly think these are the people   in my lab and i think i mentioned um jillian  is the person who’s leading this project and  

45:22he had some help on the recent behavior  analysis from a really talented undergrad darren   who actually i think Ashley and Mike met when we  went to see the mice in action so again thank you  

45:33so much for having me and i’m very happy to  answer questions and and hear your feedback  Questions and Answers

45:40awesome thank you so much dr veda um we have a  small small-ish and high-functioning group here so  

45:48after i spit out a few questions i’m just gonna  ask people to um take themselves off mute and  

45:54chime in but i want to just throw two at you  actually three um the first is on that on the  

46:02stripe if i understood you correctly and please  correct me you have further modified a mouse model  

46:09that has where you eliminate syngap only in the  straight i’m not in the rest of the brain and  

46:15on those slides you have both a head and a  knockout because part of the layman’s dogma among   the parents is that uh when you take Syngap  completely out of a mouse the mouse doesn’t  

46:26make it past a few days postnatal so everyone who  saw data on a knockout mouse was like wait what  

46:31so that’s question one question two your last two  slides your last two bullets on the last slide  

46:36talked about rescue of the phenotype if you could  sort of just talk a little bit about more about  

46:43that because that is the question you know every  parent is sitting here thinking time is brain   and they’re looking at their kid and they’re like  oh my god is it too late can they be helped like  

46:51that’s that’s the obsession so if you could just  no pressure please help our kids but i mean if  

46:57you could just elaborate on this notion of rescue  and what that might look like and translate that   a little bit and the third thing just conscious of  time and if we lose people at the end of the hour  

47:06um sydney did a great job of previewing that  dr heller is talking in our next talk and uh  

47:12she mentioned to us that she was happy to  see you’re talking because you guys were at   rockefeller together so if you could just if  you’re so inclined tell us your assessment of  

47:22of how great liz might be that would that would  be welcome as well um okay sure yeah um i guess  

47:29i’ll start with the last one first so yeah liz um  it’s great um that’s kind of the great thing about  

47:34being in science is it is a small world and we  run into people that we knew from long ago so yeah   liz heller was a student at rockefeller at  the same time i was there she was in the class  

47:44below me and yeah she’s an excellent  scientist and she’s just started her lab   a few years ago at penn and she did some really  nice work both as a grad student and as a postdoc  

47:56looking at epigenetic changes and i um and i think  she has a personal relationship to Syngap as well  

48:02with a family member and so i think it would be  as far as i understand um you know epigenetics  

48:09is not necessarily being looked at yet in the  context of sin gap and i don’t know what her exact  

48:14plans are but i think um it would be great to have  her um as part of this community and i’ve said  

48:20good things about all the support that i’ve gotten  as a new member of this community and encouraged   her to um kind of put her efforts to to study  this so i think that’s great i think bringing  

48:32in people with different ideas and different  perspectives is is really a great way to go  

48:37um okay so then uh science questions i guess  the first question about the knockout yes so  

48:43that’s definitely true we can’t really generate  um animals that have a full knockout because  

48:49that is lethal early post needle but when  we do these cell type specific manipulations  

48:55we don’t have problems with viability  or we don’t have premature mortality  

49:00and what it allows when we generate the mice  we get complete knockouts anyway and it kind of  

49:06can be helpful to include them because often the  phenotypes are more pronounced and so if we see  

49:13kind of subtle changes in the heterozygous animals  and we see you know a similar change in the same  

49:18direction that’s more pronounced and the knockout  animals that kind of just gives us more confidence   about what we’re looking at because  sometimes with the heterozygous  

49:26you can get subtle phenotypes an interesting thing  is for at least for the spine density we got the  

49:31same phenotype in heterozygous mice and knockout  animals suggesting that really loss of one copy is  

49:38is enough to really disrupt that particular aspect  which i think is interesting so i think it’s kind  

49:45of an interesting comparison to see whether  the heterozygous are whether it’s a gene dose  

49:51dependent effect or the heterozygous animals are  enough to cause complete you know as much problem  

49:56as the complete knockout so that’s why we can  we include them um when we can for those studies  

50:04um and then yes okay the second question about you  know what could we possibly do this is obviously a  

50:09critical question especially for  neurodevelopmental disorders and um you know i’ve   thought a lot about it also for tsc um so i think  that the data looked promising um from Gavin’s  

50:22lab i guess that he has that nice paper where they  show rescue of some phenotypes with even postnatal  

50:29restoration of singaporean expression and so i  think and there’s kind of similar things have been  

50:36seen for tsc not so much with gene restoration yet  but with pharmacology pharmacological treatment  

50:43and there a lot of work has been done that  clearly so for tsc we have a drug that blocks  

50:50the immediate signaling change and it’s clear that  the earlier you give that drug in development the  

50:56better the outcomes are in people and in animals  and people have defined kind of critical periods  

51:04and it’s interesting because different aspects  have different critical periods um for and again  

51:10for tsc and this may be true for some of these  other disorders as well so um you know certain  

51:15things can be rescued or improved even later in  life even in adults if you give them rapamycin  

51:23some of the behavioral phenotypes improve but  not others and then if you give you know the   drug kind of in childhood at some point in kind  of childhood you can improve more of the behaviors  

51:32but not everything and if you give it very early  you know essentially after mice are born you can   kind of fix everything so the developmental timing  is critical um i think some things might be more  

51:43able to be improved later in life than others so  um yeah i think the earlier treatment can start  

51:50the better but it doesn’t mean that  there couldn’t be beneficial outcomes   even if there is a treatment that started  later in life and i think the mice kind of can  

51:58help us get a sense of that because we have the  ability to control and test different potential  

52:04therapies and different timing of delivery and  see what kind of the critical windows might be

52:12and i guess in terms of what we could do so for  these striatal neurons it’s kind of nice because  

52:18um there is quite a lot of drugs that modulate  their activity so for example antipsychotic drugs  

52:27are targeting d cells um and so if  we knew if we know what the change is  

52:33um how these cells are affected we could kind of  come up with a drug or potential drugs to test  

52:39that might restore the activity of these cells so  that’s one thing we’ll try so kind of once we’ve   figured out what’s going on we might be able  to try some drug treatments but i think the um  

52:50you know possibly the best way to do it  would be a genetic strategy and kind of   starting where with the primary  insult which is the mutation right  

52:59and there we can do kind of this proof of  concept where if we um restore expression um  

53:05in a particular cell type we can or throughout  the brain we can show that that rescues   um but i think that’s not necessarily a viable  it’s not a viable therapeutic approach what we’d  

53:15need would be something like aso rate or a  gene therapy and those things again we can  

53:21kind of we haven’t gotten into but i  think many people are are thinking of and   sure working on and could be tested so once we’ve  kind of established the phenotypes in our models  

53:30we can we can try these things and and see um  what they what they might be able to help with

53:38well hell and this is required i gotta jump to  another zoom but that was a great talk and um  

53:45beautiful uh preliminary data so thank you so  much thank you appreciate it good to see you  

53:50see ya see everybody bye thank you okay can  you guys unmute yourself or yes you can so  

53:59so have at it i see i see catherine’s ready to go  yeah hi uh dr beethoven thank you so much for that  

54:06great talk i was wondering uh when you’re talking  about rescuing could you um you know one of my  

54:13one of my big uh sort of fears about aso stuff  in humans is going to be sort of maybe a mosaic  

54:20patterning of delivery and so i’m wondering can  you um look at a mosaic patterning of rescue in  

54:28the striatum and see what would happen as opposed  to just like changing everything you know because  

54:34with your mouse model you can you have a lot  more control over what you’re changing um do  

54:40you mean mosaic meaning like not all cells will  get the therapy or do you mean that it will only  

54:47get into certain cell types or perhaps both um  i’m not i guess i’m not sure how how those two  

54:54would be different i mean i i mean into some uh  when we’re gonna like when we’re talking about  

55:00gene therapy with our kids i keep imagining some  you know some cells getting the aso and some not  

55:06yeah and having even like a variable a  variable uh response on a cell to cell basis  

55:14so yeah that’s a great question um that’s a  challenge i think that’s a big challenge um  

55:21yeah but you’re right that it’s something that we  could try to address in animal models um so i can  

55:27tell you again we have we’re still trying to kind  of establish the the phenotypes for syngap and so  

55:34we haven’t necessarily moved to treating them yet  but for tsc we have kind of started thinking more  

55:40about that and again i think it would be somewhat  of a similar strategy or a similar situation  

55:46and so there what we’re doing is we have been  using um crispr cast nine um or other ways to  

55:54kind of manipulate the expression of genes in  for tsc we we chose not tsc itself but kind of  

56:01a downstream molecule that we wanted to suppress  and what we’ve been doing is we’ve been working  

56:08with these viruses that are developed by the  gratinaro lab at caltech that can be delivered  

56:14systemically that can cross the blood-brain  barrier um and there we definitely see that  

56:21not every cell gets the the viral um gets the  virus or expresses what we’re trying to express  

56:28and so and that is perhaps a good model for  what would happen in reality right in people  

56:34um and so we’re trying to see is that kind of um  expression going to be enough to rescue phenotypes  

56:42and we’re you know doing where hopefully  got these new viruses just this week and   are going to try that in tsc but we we  would be able to test that to try to mimic  

56:51the delivery of an aso or a crispr therapy or  some other gene therapy and which and try to  

56:57use kind of the same delivery that you would in  a person to capture that mosaicism or or whatever  

57:05so yeah it’s an open question um i think that  it’s possible that even with um not having it  

57:13expressed in every single cell it may be enough to  restore some function um but it’s something that  

57:18definitely has to be tested i think we can’t  say we can’t say for sure without testing it

57:25thank you um i actually had a second question  if i may um in your uh showing the learning  

57:32behavior you had the uh the nice graphs where in  the typical mice they went from a low activity to  

57:41a high activity and then with the syngap mice they  had sort of a sort of starburst pattern you know  

57:47they weren’t they weren’t doing the same kind of  learning so half of them were maybe doing the same   as the wild type and the other half are doing  basically the opposite or you know that kind of  

57:56thing so i was wondering with those trials are  those individual mice or are some of those mice  

58:02uh or some of those like different  trials with the same mouse and so and   ultimately what i’d want to know is can you take  some of the mice that are doing the opposite and  

58:10do they continually do the opposite or is it just  random is each mouse kind of random over time  

58:17that’s a great question um so the data  points there like each dot is an individual   mouse so um and there’s some we have tested  something around i think 10 or 12 mice um so  

58:29that’s the performance of an individual mouse that  we tested once um it is possible um to do multiple  

58:37we call them probe trials or tests it’s possible  that we could test these the same mice repeatedly   over time and see if this performance is stable  i think that would be an interesting thing to do  

58:48um we haven’t done it yet um we also would be  interesting to look um at the performance of  

58:54an individual mouse across different types of  behavior paradigms to see if there are kind of  

59:02certain subgroups or specific patterns  of responding that are reproducible or   that are consistent in different assays and  yeah looking at um individual differences is  

59:12really interesting and important um but yeah so i  can’t say how stable the behavior of those animals  

59:17those particular animals is because we only tested  them once but yes it would be interesting if they   were just kind of randomly doing something each  time or if the ones that were goal directed stayed  

59:27goal directed or the ones that were habitual  stay individual over time that’s a great question  

59:33can i can i throw in one question and then pass  it to i think dan boat and neil are ready to go  

59:39um i think if this this talk is awesome and  it’s it’s it’s just good to know that someone  

59:48else who’s like digging deep in singap  but when i say with parent so dr badap is   really a striatum person who’s digging in on  syngap and the stray item and they say to me

59:58like i don’t care about my kids stratum versus  their cerebellum the whole brain’s not working   right now is my answer that that is super  important i mean i’m not trying to be rude please  

1:00:09obviously i’m just trying to like understand  my talking points for other families   it is it’s the answer that you know the striatum  is so important that and there’s certain is it is  

1:00:18i’m i’m stuck on what you said about we can target  the straight into certain drugs or can you help me  

1:00:24translate this work to the average parent in  terms of how this knowledge can be translated

1:00:32yeah no i know exactly and so um of course i think  for the perspective of the patient we have to  

1:00:39treat all of the problems and it’s happening all  throughout the brain right so i understand that   that perspective makes total sense um i guess  what we’re trying to do is um so it’s even more  

1:00:52relevant for tsc where these genes are expressed  in every single cell type in your body right  

1:00:57and you and individuals with these mutations  have you know this constellation of problems  

1:01:02right so all right and we don’t think that all  of these problems are caused by one particular  

1:01:08cell type or one brain region or you know so we’re  trying to kind of dissociate them and understand  

1:01:14where each of these aspects is coming from so  for synep it’s likely going to be the case that  

1:01:21you know the intellectual disability and learning  and memory problems and epilepsy are going to be  

1:01:27probably driven by changes in cortex hippocampus  would be my assumption but that’s not the whole  

1:01:33picture right i mean as you all know much more  than me there’s all of these other behavioral  

1:01:38challenges right that are i i believe or i think  might be driven by changes in the striatum or in  

1:01:45the basal ganglia so if we just were treating  the cortical or hippocampal cells we probably  

1:01:51only affect a subset of the problems um and  so you know just based on my expertise and  

1:01:57the fact that we have to kind of you know dig  in somewhere we have focused on okay let’s look  

1:02:04at the stratum and the basal ganglia because we  think it’s really responsible for this subset   of behavioral problems you know related to  the autism and the other behavioral conditions  

1:02:13and yes you’re right that if we know we can figure  out what’s going on and we had a drug that kind of  

1:02:18restored the activity of those cells we would  likely only treat those particular behavioral  

1:02:24problems right and then still kind of the epilepsy  or the other issues would need to be addressed   perhaps another way so um but it’s still you  know i think it’s important because some of those  

1:02:35behavior challenges from what i’ve understood  talking to parents are really challenging and  

1:02:41they are not very much addressed clinically or  in the research so that’s kind of from for me  

1:02:46as just one scientist one lab that’s our niche  that we’re gonna try to try to tackle but of   course um there are other aspects that need to be  looked at as well uh yeah and i wasn’t saying i  

1:02:57i just wanted to understand it better thank you  there’s a parent on this phone call who doesn’t   struggle with behaviors right raise your hand  if you do if that’s you um so dan and then neil  

1:03:09yeah i totally agree with um what helen said you  know we kind of do the same things um one thing i  

1:03:15would i would think of portraying is kind of think  of each as a each of us as part of a much bigger  

1:03:21team that’s trying to get at all the answers but  we do it and i think by by digging very deep in  

1:03:26what we specialize in um so you saw today this  was a fantastic one um just the amazing toolkit  

1:03:35that helen has to actually get in there and come  up with what cell type it is and how how that  

1:03:41how a specific manipulation in a cell type  actually correlates with its specific behavior  

1:03:49and i think that’s that’s one of the keys  is that we do understand what regions   underlie specific behaviors it allows us to get  more specific later on um and i know i study  

1:04:00autism as well and it’s very very different from  person to person like just the the spectrum alone  

1:04:07of behaviors that you have you might want more  personalized medicine in the future where we can   actually target specific behaviors and it might  allow us to look at specific brain regions uh as  

1:04:18as not only a diagnostic but maybe also as a  therapeutic yeah no thank you neil do you have  

1:04:26a question i’m gonna do just one uh i won’t uh i  won’t go i don’t believe you one question however  

1:04:32helen it is gonna be an incredibly unfair question  for you um so while you’re figuring out the  

1:04:38biology and i’m with mike and the others very very  focused on that that’s going to be very exciting  

1:04:43there is one other aspect that all parents  have which is we’re trying to deliver  

1:04:51occupational therapies learning therapies along  the way you’ve got educators caregivers parents  

1:04:57and i’m wondering and you may not have anything  now but as you study these mouse models it’ll be  

1:05:04awesome to see if there is ever an opinion  your team had over hey look if we focused on  

1:05:12gross motor in the first year of life and forgot  everything else that might be great because  

1:05:20what i’m really wondering and i’ve you know my  daughter’s 14 um i don’t want to leave anything  

1:05:26on the table from a therapy point of view  and what triggered my thought was you know   how does a singapian view goals differently you  know over seconds minutes hours days and does  

1:05:39that knowledge help a therapist um educate you  know in other words can the actual otpt speech  

1:05:49school learning change as a result of what  you see in a mouse that is a leap that no  

1:05:54scientist would ever take i understand  but as you link into behavioral sciences  

1:06:00if you think you want to throw a few bones  off the bus i think every parent would love to  

1:06:06to get any opinion uh because  we’ll try anything anything crazy   um no that’s a that is um an awesome question and  a great thought so yes i think i mean ultimately  

1:06:18well the stride and one it’s one of its jobs  is to do learning right and it doesn’t do  

1:06:23you know kind of um spatial navigation or  memorizing phone numbers type of learning it  

1:06:29is different types of learning um but it’s still  learning that can be potentially modified and  

1:06:36trained with the right approach so i think that’s  a great idea i think yeah basic scientists have  

1:06:43at least biology perhaps more so in psychology  have not been done so much in terms of behavioral  

1:06:48interventions it’s probably challenging in mice  um but i think that’s a great idea i mean yes  

1:06:54if we see if we know more about what strategy  these mice are using or why they’re performing  

1:07:00you know differently in these  there are learning tasks right   why their ultimate behavior is different we could  think about um you know different training regime  

1:07:09or you know for all of these types of training  tasks we have parameters that we can tweak or   train you know maybe if we train them for longer  they will have more similar performance or  

1:07:19maybe if we train them with a slightly different  strategy then maybe they would um you know perform  

1:07:25more along the line so that’s a great suggestion  um i think that would be great to try um  

1:07:31i do we have a colleague of mine linda wilbrat  who’s in the psychology department and she is   very interested in that so she’s um not so much  studying disorders per se but studying you know  

1:07:42how we learn and the neural circuits behind it  and if we know that then we can devise much better  

1:07:49inter behavioral intervention strategies to kind  of modulate or adjust that learning or if we  

1:07:55know kind of what individuals with autism how  they learn um you know and that might be kind  

1:08:01of abnormal we can kind of use that to help  them learn kind of the things that we’re trying  

1:08:07so yeah i think that’s a great suggestion again  it’s just challenging to do it in mice mice are  

1:08:12not the easiest um to get them to do what you want  them to do but i think it’s something that could  

1:08:18be considered and is a great idea um yeah  right thanks any other parents chiming in  

1:08:26sydney martha peter jj pablo there’s a couple  yeah i have a question oh sorry i’ll have food  

1:08:32for the chat go ahead martha oh no i i i know  you mentioned that maybe some antipsychotics you  

1:08:38were expecting that they will improve the indirect  pathway of the cells that is what you show in your  

1:08:45study that was the problem with synga what  are you expecting like i know there are some  

1:08:50kids that we have i think an effects or that  they said they are doing better with behavior  

1:08:55and and to the point that you said that um  probably behavior is not what first goal actually  

1:09:01i think there was um the in one of the questions  that we asked all the parents behavior was  

1:09:09one of the goals to control better than even  seizures because it’s such a big deal for us then  

1:09:16i mean this is very helpful for us to have some  guidance on behavior yeah yeah i agree so i should  

1:09:23say that um you know the antipsychotics i just  threw out as an example of kind of a class of  

1:09:28drugs where you have a lot of different types that  have differential activity at different types of   receptors that are all very much in the striatum  and so um i i can’t say yet if those types of  

1:09:40drugs or which one would be helpful because i  think we don’t know yet enough about the cellular   biology of how the syngap mutation affects the  activity of these cells so basically we need to  

1:09:50know is there at a very crude level is there too  much activity in these cells or too little or is  

1:09:55the activity fine there’s just abnormal plasticity  perhaps so i think once we have done those  

1:10:01experiments which again you know over the next  six months is really um our focus then i’ll have  

1:10:07a much better answer of what we might be able to  do pharmacologically to kind of tweak the activity  

1:10:12of these cells um so yeah unfortunately i can’t  say at this point what would be a good strategy  

1:10:18um but soon again when we know more about the cell  activity cell biology we might have a better um  

1:10:25idea of what would be good to try and then again  we could in theory try them in the animal models  

1:10:32thank you aj do you want to ask your  question or do you want me to read it

1:10:40stephen’s asleep okay so dr made up if you go to  the chat i can read this to you too but it’s a   long one how how can the biology correlate  to therapy and medications to help recur  

1:10:51indirect dopamine cell recur i think  procurement’s rescue indirect dopamine cells   if meds can restore the function of these affected  cells would you expect behavior in learning  

1:11:01yeah so there’s some heavy  hitting parents on this call   no it’s great i mean i i think it’s great um  let’s see i’m just gonna make sure i understand  

1:11:13right so yeah so this is exactly the goal is that  um yeah again once we have a bit more information  

1:11:21about what’s kind of wrong with these cells or  what these cells are doing differently let’s say   when they have disrupted sin gap then  i think we might have at least um  

1:11:32you know in terms of therapies that could be given  to patients that would be the next step but we   would at least have a bunch of pharmacological  tools that we could test in mice right at least  

1:11:40to do the proof of concept right if we were to  slightly upregulate the activity of this receptor  

1:11:46or slightly you know decrease the activity of that  receptor that would restore the cellular function  

1:11:53and we would test then is that sufficient to  improve the behavior that would be the ultimate   test because if we kind of fixed or improved  the cellular biology but the animals still had  

1:12:04abnormal behavior that’s obviously not going to  be a great thing to pursue as a therapy so yeah   i think the question is about um yeah we would  want a medication that targeted the cells and  

1:12:14the cellular problems and fix those first or you  know improve the function and then absolutely test  

1:12:21if that was good enough to improve the behavior  because and if it was then that suggests that   it’s kind of a potential promising thing and the  next step would be to look and see if there’s  

1:12:29drugs that target those receptors or pathways  that are already you know fda approved and  

1:12:35you know if not go from there so that that’s would  be the process that we would go down i have a  

1:12:43broad and more unfair question than neil had that  i’d love to throw at you because you’re so smart  

1:12:49you’ll say something cool but before i do that any  other parents have things they want to chime in   here yeah yes just one quick question um dr beta  on um i might have missed this earlier in the in  

1:13:00the discussion i had a work call so my apologies  on tsc um did you guys have you guys identified  

1:13:06any sort of medication to improve the behavior  in tsc and what does that look like yeah so tsc  

1:13:12it’s a little bit different um so then there is an  fda approved drug which um it’s rapamycin or kind  

1:13:19of the i forget the the derivatives of rapamycin  um and it works by blocking the activity of this  

1:13:26um protein called mtor and that’s because this tsc  complex is a direct negative regulator of mtor and  

1:13:35so when you have mutations in tsc this complex  is no longer functional and you have basically   deregulated or or m2 signal it’s always on so this  drug blocks the activity of that kind of next step  

1:13:46downstream target and this is fairly effective  so it works for the tumor it helps to  

1:13:55kind of reduce the tumor burden in patients it’s  pretty effective for seizures but not perfect so  

1:14:01i think the the first major clinical trial showed  something like 40 percent seizure reduction in 40  

1:14:07percent of patients so pretty good but not  um complete the challenge is they recently  

1:14:13did clinical trials for autism and cognitive  impairments in tsc and unfortunately those failed  

1:14:19with rapamycin there was two different trials  um and the reasons suggested were that either  

1:14:25the treatment was started to lead so i  think most of the people enrolled were  

1:14:30older children or teenagers maybe  even adults i don’t remember   um but i think you know the youngest was probably  like six or eight and the trials only went for  

1:14:39six months they thought maybe that wasn’t long  enough other possibilities are that rapamycin  

1:14:46doesn’t get into the brain all that well and  in our mouse models we’ve actually seen that  

1:14:51it has incomplete effect on dopamine neurons  for example which we think are important for  

1:14:57the cognitive inflexibility so if the drug is  not getting into those cells then that might   also be a reason why it didn’t work very well  for that particular behavior but that’s purely  

1:15:06speculative so that’s the strategy for tsc the  problem is that um or the current strategy the  

1:15:14um for epilepsy other you know other types of  medications have been employed and most recently  

1:15:23cannabidiol cbd has been used with success for  the epilepsy so those are the things in tsc  

1:15:31rapamycin is a little problematic because you have  to give pretty high doses to get it into the brain  

1:15:36and there are systemic problems because mtor is  expressed everywhere in the body and so there’s  

1:15:42problems with like liver like kind of metabolic  problems there’s immune suppression so it’s not  

1:15:49great to be on that um but it does improve um  some aspects so we have been for tsc working  

1:15:56on a genetic strategy that would be a little  bit more targeted and at least trying to show  

1:16:02proof of concept that we could do it just in  the brain to kind of avoid these more systemic  

1:16:08problems and again it’s it’s pretty early but  we’re um that’s what we’re pursuing for tsc  

1:16:14thank you catherine i see you’re unmuted do you  want to ask a question yeah thank you i wanted to  

1:16:21just say i have a 19 year old son and i really um  the habituation and behavior stuff is really you  

1:16:28know top of mind for us and i heard you use a word  early in your talk that uh the word addiction and  

1:16:35i have for a long time thought that my son behaves  kind of like he gets addicted to some behaviors  

1:16:41so he’ll like enjoy something like say take a  carousel ride at the zoo he’ll enjoy it i’ll   start leveraging that to get him to do some work  because that’s the only way you can get him to do  

1:16:50anything is to give him you know sort of show here  you’re going to get this thing now do the work   he’ll do the work then he gets the thing and so  then carousel rides elevator rides certain foods  

1:17:00songs like any any of the things i can name that  have been his kind of rewards they start out as  

1:17:06making him happy then they make him really happy  then they make him sort of super weirdly excited   then pretty soon after that he’ll be over time  you know as this is going on he’ll start you  

1:17:16know sort of screaming and being seeming like  he’s in pain and then he’ll just start this huge   injurious behavior cycle and it sort of has  taken me a long time to understand that like  

1:17:26pretty much everything’s gonna sort of be poisoned  in this way at some point and so not giving him  

1:17:31the same things even though they’re the things  he likes and i like to give him the things he   likes i kind of have to stop the cycle myself  and so i just wanted to put that out there as a  

1:17:42something that i hope you can sort of look  at i might not be the same in the mice but   that sort of habituation is really interesting  yeah that’s an interesting point i mean that’s  

1:17:52helpful to hear about and learn about i mean  these brain circuits and the cells that we’re   talking about are exactly the ones or that  are involved in addiction um and there is  

1:18:02i think some overlap in terms of the cell  at least at the cellular and circuit level  

1:18:08or that’s part of the hypothesis um and not just  addiction but also obsessive-compulsive disorder  

1:18:15um people have looked in animal models at these  same cells and circuits and so the idea is that  

1:18:21there may be these synaptic changes in  these cells that yes are causing kind of um  

1:18:26increased habit formation and that  might manifest slightly differently   in addiction or compulsion or repetitive behavior  but that the same kind of culprits might be at  

1:18:37play and there’s a nice nice review article are  a couple of review articles that were written um  

1:18:43by some junior faculty that are working on other  autism risk genes where they specifically say you  

1:18:48know changes in these addiction circuits might be  also important for autism and for these repetitive   and flexible behaviors so very like almost exactly  what you’re suggesting um so i do think that there  

1:18:58are some common pathways here i don’t yeah i  don’t i think there are some key differences it’s   not addiction per se but i think some of the same  kind of over learning or kind of positive feedback  

1:19:10may also happen to cause these kind of fixated or  inflexible interests and so that’s a great point

1:19:20first katherine thank you i mean this this gene  was only identified clinically 10 10-ish years   ago right so most of us have kids who are under  10 a few people like me all have teenagers and  

1:19:31then catherine so when we when we meet older  parents that you can see the rest of us get   extra quiet when they talk because we want to my  older parents i mean parents of older kids we get  

1:19:41very quiet because we want to hear exactly what  they’re saying because we’re all terrified about   the future and i just want a second one catherine  said tony loves stuff he loves it more it loves it  

1:19:49more he works it it becomes an obsession it’s  a nightmare and i’m so sick of cars now we’re   now i know now i own every mr men book in the  world you know i just i just need to keep his  

1:19:58obsessions less than five dollars each um but my  here’s my tough question for you helen because  

1:20:04you’re sitting here talking about drugs and as  you you as you surely know and every parent on   this call knows you know stoke released a paper  and now their aso that may be promising for syngap  

1:20:14and they may bring commercially developed is  could happen and we know that rick presented a  

1:20:23a potential aso at our srf roundtable at aes last  year and we know of at least one other and then we  

1:20:30you know the last call we had professor cadam  here who was talking about a potential drug that   anyway so there’s these talks of asos  and then there’s talks of drugs and  

1:20:39then there’s talks of prime editing and all  this future sci-fi and some parents look at  

1:20:46me and say well why are we talking about drugs  because if we have an aso won’t that cure it   and i have and i find myself in this conversation  where it’s like well look hey we don’t know about  

1:20:55delivery b we don’t know how efficacious is  going to be or how much it’s going to cost   and you know the aso i’ve had some i’ve heard  some people refer to as well it’s a workaround  

1:21:02but it doesn’t solve a problem for that many prime  editing which in my head goes into the sci-fi more   than five years out bucket and then there’s people  who are like and then i talk to the leadership of  

1:21:11say the fragile x organization fragile x started  doing research they were like we were all about   asos and gene therapy and you know what’s helped  the most kids good old-fashioned small molecules  

1:21:21like do not give up on small molecules so i love  your perspective on this but what i say to parents  

1:21:27is it’s not obvious of what therapy is going  to work on what kid and it’s better to have a  

1:21:33lot of arrows in your quiver so yes asos could be  game changing but we could still have symptoms we  

1:21:39need to treat there could be some things we can’t  rescue so we need small and one day when it’s cost   effective and it’s available all of these other  future gene therapies yes by all means but don’t  

1:21:50think oh we have an aso we’re done it’s what i  say to people so you’re the professor would you  

1:21:55correct or amend my little speech there and tell  me how i can appropriately in your opinion talk  

1:22:01to other parents about this um well i think i mean  i think you’re exactly right and i should say that  

1:22:06um you know i’m a research scientist not a  clinician so that’s an important disclaimer   um but i think i would agree 100 that it’s  important to have an arsenal of approaches right  

1:22:16especially for kind of complex disorders that may  present differently in different people that have  

1:22:22um different aspects that may need to be treated  differently that more are more or less amenable   to different things so i think absolutely you  know having a multitude of things to be able to  

1:22:32throw at the problem is going to be you know  most likely the best way to go um you know i  

1:22:39i personally agree with the opinion that you know  maybe now or in the future that these kind of gene  

1:22:45type targeted therapies are really going  to be helpful because yes they will kind of   get to the source of the problem but they’re still  new enough and there’s still a lot of questions  

1:22:54like um i think catherine was bringing up about  the delivery and will it hit all the sell as many   cells as you need and will it hit the right cells  like these are really unanswered questions right  

1:23:03um and they will be answered slowly but it’s  going to take you know clinical trials and a  

1:23:08lot of work so um i think it’s absolutely worth  pursuing those things because if they work they  

1:23:14will that’s what we want right but yeah there  are a lot of you know they may or may not work or  

1:23:20there may be still a lot of troubleshooting and  trial and error to figure out first so what i  

1:23:25was kind of suggesting you know and the reason i  brought up antipsychotics again not that i think   that that’s necessarily the the specific thing we  want to do but those are available now right and  

1:23:34could be enter at least some things are fairly  well tested and kind of the risks are known um  

1:23:42and they’re things that could be tried to kind of  improve behavior immediately potentially right um  

1:23:48so i i think that you know gathering information  about if any of those things could be helpful  

1:23:54you know right now um or you know potentially even  in older individuals um that’s i think importance  

1:24:01right so i think you want to have all of those  things and um yes if one of those kind of asos  

1:24:06or gene therapy approaches ends up working  um and all of the hurdles are crossed then  

1:24:12we may not need those other small molecules but  i you know it might be a while and as you said   the cost and the invasiveness of those things is  also consideration again small molecule drug is um  

1:24:23relatively inexpensive relatively you know  low risk in terms of administering it um  

1:24:29so yeah i think i think pursuing any and all  of those things is worthwhile at this point

1:24:37thank you and thank you for your time and your  accessibility and being so um gracious with this  

1:24:43as i we’re an hour and a half so we’re probably  past whatever anybody thought this would be  

1:24:48are there any other questions  do you want to throw it   okay well thank you dr beta thank you for  the families thanks jillian for being here  

1:24:57um and anna and daniel and are you guys  here thank you very much not good thank you

1:25:06thank you everyone thank you thank you thanks  everyone it’s a pleasure to meet you all thanks  

1:25:12for organizing making sydney and if you have  any questions or you want to talk to families or  

1:25:18parents or whatever let us know we’re here yeah  absolutely um thank you so much again it’s been  

1:25:23great to be part of this very engaged community it  makes what we’re doing uh you know it gives us the  

1:25:31immediate relevance of what we’re  doing which is really helpful thank you okay all right take care