Reversing GABA polarity corrects synaptic physiology and behavioural deficits in young adolescent Syngap1+/- mice

Reversing GABA polarity corrects synaptic physiology and behavioural deficits in young adolescent Syngap1+/- mice | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Reversing GABA polarity corrects synaptic physiology and behavioural deficits in young adolescent Syngap1 +/- mice Vijaya Verma, MJ Vijay Kumar, Kavita Sharma, Sridhar Rajaram, and 4 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-682039/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract Haploinsufficiency in SYNGAP1 is implicated in Intellectual Disability (ID) and Autism Spectrum disorder (ASD) and affects the maturation of dendritic spines. The abnormal spine development has been suggested to cause disbalance of excitatory and inhibitory (E/I) neurotransmission at distinct developmental periods. In addition, E/I imbalances in Syngap1 +/- mice might be due to abnormalities in K + -Cl - co-transporter function (NKCC1, KCC2), in a similar manner as in the murine models of Fragile-X and Rett syndromes. To study whether an altered intracellular chloride ion concentration represents an underlying mechanism of altered function of GABAergic synapses in Dentate Gyrus Granule Cells of Syngap1 +/- recordings were performed at different developmental stages of the mice. We observed that neurons at P14-15 of Syngap1 +/- mice had depolarised membrane potential and a decreased Cl - reversal potential. The KCC2 expression was decreased compared to Wild-type (WT) mice at P14-15. Furtherly, the small molecule GSK-3β inhibitor, 6-bromoindirubin-3`-oxime (6BIO), was tested in an attempt to restore the function of GABAergic synapses. We discovered that intraperitoneal administration of 6BIO during the critical period or young adolescents normalized an altered E/I balance, the deficits of synaptic transmission, and behavioral performance like social novelty, anxiety, and memory of the Syngap1 +/- mice. In summary, altered functionality of GABAergic synapses in Syngap1 +/- mice is based on a reduced KCC2 expression and a subsequent increase in the intracellular chloride concentration that can be counteracted by the small molecule 6BIO. The 6BIO sufficiently restored cognitive, emotional, and social symptoms by pharmacological intervention, particularly, in adulthood. Neurobiology of Disease Cellular & Molecular Neuroscience Autism spectrum disorder Intellectual disability Syngap1 heterozygous mutation GABA NKCC1 KCC2 GSK-3β Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Full Text Supplementary Files SI6biocorrectspathophysiologyVermaClementetal.pdf SI: Reversing GABA polarity corrects synaptic physiology and behavioural deficits in young adolescent Syngap1+/- mice Cite Share Download PDF Status: Posted Version 1 posted You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. 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Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-682039","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":37042532,"identity":"493785b4-86cf-49f6-849b-c5500b0bcc3d","order_by":0,"name":"Vijaya Verma","email":"","orcid":"","institution":"Jawaharlal Nehru Centre for Advanced Scientific Research","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Vijaya","middleName":"","lastName":"Verma","suffix":""},{"id":37042533,"identity":"d991549a-80b8-40f8-9ec7-75e3b560cc29","order_by":1,"name":"MJ Vijay Kumar","email":"","orcid":"","institution":"Jawaharlal Nehru Centre for Advanced Scientific Research","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"MJ","middleName":"Vijay","lastName":"Kumar","suffix":""},{"id":37042534,"identity":"dcfcce58-d142-421a-884c-421538cae121","order_by":2,"name":"Kavita Sharma","email":"","orcid":"","institution":"Jawaharlal Nehru Centre for Advanced Scientific Research","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Kavita","middleName":"","lastName":"Sharma","suffix":""},{"id":37042535,"identity":"fc9d8706-da4d-41f7-8983-7976356d11e9","order_by":3,"name":"Sridhar Rajaram","email":"","orcid":"","institution":"Jawaharlal Nehru Centre for Advanced Scientific Research","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Sridhar","middleName":"","lastName":"Rajaram","suffix":""},{"id":37042536,"identity":"63794d17-b294-46f7-bb04-636b6d52c823","order_by":4,"name":"Ravi Muddashetty","email":"","orcid":"","institution":"InStem","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Ravi","middleName":"","lastName":"Muddashetty","suffix":""},{"id":37042537,"identity":"13b6184c-0e29-4857-b76f-9aefb687ec87","order_by":5,"name":"Ravi Manjithaya","email":"","orcid":"","institution":"Jawaharlal Nehru Centre for Advanced Scientific Research","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Ravi","middleName":"","lastName":"Manjithaya","suffix":""},{"id":37042538,"identity":"5d688e7d-b892-441b-8d11-7fe9a664f2b2","order_by":6,"name":"Thomas Behnisch","email":"","orcid":"","institution":"2Institutes of Brain Sciences, Fudan University","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Thomas","middleName":"","lastName":"Behnisch","suffix":""},{"id":37042531,"identity":"7e04ddda-29a7-447c-bab2-4ccec57dff36","order_by":7,"name":"James Clement","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA3klEQVRIiWNgGAWjYDACdgglx9gAF0JiYgXMYNLAmHQtiQSUIQH+ZuajGz7u+JPePLv54cefexjk+RuY2x7g0yJxmC3t5swzBrmNc44ZS/M8YzCccYCx3QCfFgNmHrPbvG1ALTNyGKQZDjAwbmBgbJPAr4X/2+2/bQbpjDNymH/+OMBgT4QWHrbbjG0GCUAtbBI8BxgSCWoB+sXsZm+bsWHjjDQza54DEskzDhPQwt/e/OzGzzY5ecMZyY9v/jhgY9vf3v4MrxY4MGyA2AqLKSKAPLEKR8EoGAWjYOQBALHKRMPH4wo2AAAAAElFTkSuQmCC","orcid":"","institution":"Jawaharlal Nehru Centre for Advanced Scientific Research","correspondingAuthor":true,"submittingAuthor":false,"prefix":"","firstName":"James","middleName":"","lastName":"Clement","suffix":""}],"badges":[],"createdAt":"2021-07-03 08:33:31","currentVersionCode":1,"declarations":{"humanSubjects":false,"vertebrateSubjects":true,"conflictsOfInterestStatement":true,"humanSubjectEthicalGuidelines":false,"humanSubjectConsent":false,"humanSubjectClinicalTrial":false,"humanSubjectCaseReport":false,"vertebrateSubjectEthicalGuidelines":true,"coiExplicitlySet":false},"doi":"10.21203/rs.3.rs-682039/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-682039/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":11163207,"identity":"bcc46eeb-9fb2-4521-ad81-e91e36ff0476","added_by":"auto","created_at":"2021-07-06 16:40:27","extension":"tif","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":53116,"visible":true,"origin":"","legend":"Neurons of Syngap1+/- mice show a shift in chloride reversal potential (ECl-) at P14-15:\nA) Left, Evoked representative Cl - mediated current traces at the indicated holding potentials of a Gramicidin-based perforated voltage-clamp experiment. Right, The graph to the right summarises the relationship of holding potential (mV) to current amplitude for one representative experiment and depicts the trend as a linear fit curve. The experiments\nwere conducted at P14-15 in WT mice. B) Same as A but in P14-15 Syngap1+/- . C) The graph summarises the reversal\npotentials of GABA receptor-mediated Clcurrent (ECl-\n) in WT as well as Syngap1+/- at the indicated postnatal ages.\nP4-5: WT: N=6, n=7, 35±1.37; Syngap1+/-\n: N=4, n=7, 48±3, (NS: p\u003e0.05); P7: WT: N= 3, n= 4, 44±2.78; Syngap1+/- \nN=3, n=5, 47±3,(NS: p\u003e0.05); P8: WT N=5, n=6, 46±1; Syngap1+/- : N=4, n=8, 51±4.04, NS: p\u003e0.05; P14-15: WT:\nN=3, n=7; Syngap1+/-\n:N=4, n=6, ***p\u003c0.001; P21-23 WT, N=4, n=6, 65±2; Syngap1+/- : N=3, n=7, 64±2, NS: p\u003e0.05;\nP≥90: WT: N=7, n=15, 68±1.53; Syngap1+/- , N=5, n=9, 71±2.18, NS: p\u003e0.05. F (5, 76) = 6.83, p\u003c0.0001 for the interaction. Data are presented as single data points and means ± SEM. N: number of mice, n: number of cells. Two way ANOVA, Tukey’s multiple comparisons test.","description":"","filename":"Figure1.tif","url":"https://assets-eu.researchsquare.com/files/rs-682039/v1/258859eb9ea68472d2c0f5cc.tif"},{"id":11163446,"identity":"178b25ee-75ac-4207-8721-6e1474f1438f","added_by":"auto","created_at":"2021-07-06 16:43:27","extension":"tif","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":444243,"visible":true,"origin":"","legend":"Age-dependent expression levels of NKCC1 and KCC2 Clco-transporters in WT and Syngap1+/- mice: A) Top, Representative NKCC1 immunoblots at P8 are depicted. B) Bottom, line graph summarizes NKCC1\nexpression levels at different post-natal ages for WT as well as Syngap1+/-\n. P4-5 (WT) N=7, 0.48±0.1, (Syngap1+/- )\nN=11, 0.58 ±0.03 (p: 0.1320); P7 (WT) N=7, 1 ±0.1, (Syngap1+/- 715 ) N=8, 0.87 ±0.1228 (p\u003e0.05); P8 (WT) N=6, \n28\n0.72±0.05, (Syngap1+/-\n) N=6, 0.98±0.09 (*p\u003c0.05); P14-15 (WT) N=13, 0.8±0.05, (Syngap1+/- ) N=10, 0.8±0.07\n(p\u003e0.05); P21-23 (WT) N=7, 0.7±0.03, (Syngap1+/- ) N=7, 0.68±0.06 (p\u003e0.05); ≥P90 (WT) N=10, 0.7±0.07,\n(Syngap1+/- ) N=10, 0.79±0.08 (p\u003e0.05). F (5, 90) = 1.48, p=0.2027 for the interaction. C) Top, Representative P14-15 immunoblots for KCC2 are shown. D) Bottom, line graph summarizes KCC2 expression level during development in\nWT as well as Syngap1+/-. (P4-5 (WT) N=9, 2.3±0.18, (Syngap1+/- ) N=9, 2.8±0.18 (p\u003e0.05); P7 (WT) N=8, 2.4±0.17,\n(Syngap1+/) N=8, 2±0.17 (p\u003e0.05); P8 (WT) N=5, 3.7±0.12, (Syngap1+/- ) N=6, 6.2±0.79 (**p\u003c0.01); P14-15 (WT)\nN=7, 5.717±0.7434, (Syngap1+/-\n) N=8, 2±0.3 (***p\u003c0.001); P21-23 (WT) N=7, 4.872±0.6442, (Syngap1+/- ) N=7,\n3.4±0.1 (p\u003e 0.05); ≥P90 (WT) N=10, 2.3±0.2, (Syngap1+/- 723 ) N=10, 2.8±0.2 (p\u003e0.05). F (5, 82) = 14.46, p\u003c0.0001 for the interaction. Data are presented as mean ± SEM. N: number of mice. Two-way ANOVA, Tukey's multiple comparisons test. E) Representative immunofluorescence images depicting SYNGAP1 and KCC2 localisation and expression\npattern in hippocampus region (DGGC for all age group and sections) in WT and Syngap1 +/- mice at P8, 14-15 and ≥90. White arrows indicate punctate expression pattern of KCC2 and SYNGAP1. Blue colour represents the Hoescht staining of the nucleus, green coloured puncta are of SYNGAP1 protein, and KCC2 puncta surrounding soma and\ndendrites are presented in red. F) Bar graph representing the integrated density of WT and Syngap1+/- in the individual\nage group is shown in front of the respective panel of P8, 14-15 and ≥90. P8 (WT) n=4, 1165283±64324, (Syngap1+/- \n) n=5, 1426211±47106 (*p\u003c0.05); P14-15 (WT) n=7, 1202925±43917, (Syngap1+/- ) n=6, 766779±18128\n(***p\u003c0.001); P≥90 (WT) n=6, 1697380±22155, (Syngap1+/- ) n=8, 1656486±32631 (p\u003e0.05). Scale bar = 20 μm. Data are presented as mean ± SEM. Unpaired t-test, n: number of sections.","description":"","filename":"Figure2.tif","url":"https://assets-eu.researchsquare.com/files/rs-682039/v1/b76cc188c26ae66324182f80.tif"},{"id":11163449,"identity":"959d9323-48e5-4025-9757-b91af2ccb12d","added_by":"auto","created_at":"2021-07-06 16:43:28","extension":"tif","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":81915,"visible":true,"origin":"","legend":"Figure 3: 6BIO corrects hyperactivity and anxiety deficits in Syngap1+/-\nA) Chart depicting the regime for 6BIO intraperitoneal injection (5 mg/kg) and categorisation of age groups. B) Total distance travelled by the mice in open field chamber was grouped and shown as individual data points for P10-80 where behaviour was done at P16 WT–Vehicle: N=20; Syngap1+/-–Vehicle: N=11; WT–6BIO: N=16; Syngap1+/-–6BIO: N=14, F(1, 57) = 14.83, p=0.0003, C) P10-80 where behaviour was done at P42, WT–Vehicle: N=17; Syngap1+/-–Vehicle: N=9; WT–6BIO: N=15; Syngap1+/-–6BIO: N=9, F (1, 44) = 4.752, p=0.0347, and D) P30-80, WT–Vehicle: N=14; Syngap1+/-–Vehicle: N=14; WT–6BIO: N=16; Syngap1+/-–6BIO: N=16, F (1, 56) = 0.4686, p=0.4965. E) Number of entries in the centre as a measure of anxiety was grouped and shown as individual data points for P10-80 where behaviour was done at P16, WT–Vehicle: N=20; Syngap1+/-–Vehicle: N=11; WT–6BIO: N=16; Syngap1+/-–6BIO: N=14, F (1, 57) = 18.01, p\u003c0.0001, F) P10-80 where behaviour was done at P42, WT–Vehicle: N=18; Syngap1+/-–Vehicle: N=10; WT–6BIO: N=15; Syngap1+/-–6BIO: N=11, F (1, 50) = 2.194, p=0.1449, and G) P30-80, WT–Vehicle: N=13; Syngap1+/-–Vehicle: N=12; WT–6BIO: N=15; Syngap1+/-–6BIO: N=18, F (1, 54) = 6.002, p=0.0176. Two-way ANOVA, Tukey's multiple comparisons test.\n","description":"","filename":"Figure3.tif","url":"https://assets-eu.researchsquare.com/files/rs-682039/v1/881f6fd56741ea030ca92e21.tif"},{"id":11163447,"identity":"cd0fecf5-bc82-44a0-b576-281935298fc7","added_by":"auto","created_at":"2021-07-06 16:43:28","extension":"tif","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":127565,"visible":true,"origin":"","legend":"Figure 4: 6BIO corrects memory recognition and sociability deficits in Syngap1+/- particularly in the post-critical period of development: \nA) Discrimination index was plotted as the measure of recognition memory and plotted as individual data points for P10-16 where behavior was done at P80, WT–Vehicle: N=11; Syngap1+/-–Vehicle: N=6; WT–6BIO: N=9; Syngap1+/-–6BIO: N=14, F (1, 36) = 14.76, p=0.0005, B) P10-80 where behavior was done at P80, WT–Vehicle: N=16; Syngap1+/-–Vehicle: N=7; WT–6BIO: N=11;: N=10, F (1, 40) = 1.982, p=0.1669, and C) P30-80 where behavior was done at P80, WT–Vehicle: N=8; Syngap1+/-–Vehicle: N=7; WT–6BIO: N=9; Syngap1+/-–6BIO: N=15, F (1, 35) = 7.687, p=0.0089. Social interaction and preference was evaluated as time spent with stranger1 as compared to empty jar, and time spent with stanger2 as compared to stranger1 respectively for D) P10-16 where behavior was done at P80, WT–Vehicle: N=12; Syngap1+/-–Vehicle: N=10; WT–6BIO: N=12; Syngap1+/-–6BIO: N=14, F (3, 88) = 1.481, p=0.2252, G) WT–Vehicle: N=12; Syngap1+/-–Vehicle: N=10; WT–6BIO: N=12; Syngap1+/-–6BIO: N=14, F (3, 88) = 0.6549, p=0.5820, E) P10-80 where behavior was done at P80, WT–Vehicle: N=9; Syngap1+/-–Vehicle: N=6; WT–6BIO: N=10; Syngap1+/-–6BIO: N=10, F (3, 62) = 3.722, p=0.0158, H), WT–Vehicle: N=9; Syngap1+/-–Vehicle: N=8; WT–6BIO: N=10; Syngap1+/-–6BIO: N=10, F (3, 66) = 2.692, p=0.0532, and F) P30-80 where behavior was done at P80, N=12; Syngap1+/-–Vehicle: N=14; WT–6BIO: N=12; Syngap1+/-–6BIO: N=18, F (3, 104) = 2.909, p=0.0381, I), WT–Vehicle: N=12; Syngap1+/-–Vehicle: N=13; WT–6BIO: N=12; Syngap1+/-–6BIO: N=18, F (3, 102) = 2.616, p=0.0551. Two-way ANOVA, Tukey's multiple comparisons test.\n","description":"","filename":"Figure4.tif","url":"https://assets-eu.researchsquare.com/files/rs-682039/v1/24bb65659fc401faf5154f2a.tif"},{"id":11163212,"identity":"c9469208-6dcb-4921-9116-fa54251056bd","added_by":"auto","created_at":"2021-07-06 16:40:28","extension":"tif","order_by":5,"title":"Figure 5","display":"","copyAsset":false,"role":"figure","size":86782,"visible":true,"origin":"","legend":"Figure 5: 6BIO hyperpolarises GABA reversal potential at P15-16 in Syngap1+/- mice and corrects LTP in the post-critical period of development: \nA) Mice were injected 6BIO from P30-80; thereafter, fluoroethyl-based seizure threshold was evaluated and plotted as grouped data showing individual points for tonic-clonic seizure. 6BIO increased the threshold for tonic-clonic, similar to WT levels, in Syngap1+/-. F(1,25)=3.354, p=0.0790, WT–Vehicle: N=9; Syngap1+/-–Vehicle: N=7; WT–6BIO: N=7; Syngap1+/-–6BIO: N=6. B) Grouped data for EGABA estimated from I-V curve from individual WT (Vehicle and 6BIO treated) and Syngap1+/- mice (Vehicle and 6BIO treated). WT-Vehicle: N=5, n=5; Syngap1+/--Vehicle: N=4, n=6; WT-6BIO: N=3, n=5; Syngap1+/--6BIO: N=3, n=7; F(1,19)=9.761, p=0.0056. C) For Group II, where injections were done from P10-80, WT-Vehicle: N=4, n=8; Syngap1+/--Vehicle: N=4, n=7; WT-6BIO: N=4, n=8; Syngap1+/--6BIO: N=4, n=6, F(1,25)=2.047, p=0.1649 and D) Group III, where injections were done from P30-80, WT-Vehicle: N=3, n=6; Syngap1+/--Vehicle: N=4, n=6; WT-6BIO: N=5, n=9; Syngap1+/--6BIO: N=5, n=9, F(1,26)=4.731, p=0.0389, slope of fEPSP was normalised to mean value of 15-minute baseline period and 45-minute post-LTP recordings were performed. Example traces are average of those recorded in 1-2 min around the time point indicted (I and II). Two-way ANOVA, Tukey’s multiple comparisons test.\n","description":"","filename":"Figure5.tif","url":"https://assets-eu.researchsquare.com/files/rs-682039/v1/40f944b9be2d273cf87fb838.tif"},{"id":13654171,"identity":"d3dd3a5a-8d0f-4c85-9523-41ff1db90753","added_by":"auto","created_at":"2021-09-17 09:56:34","extension":"pdf","order_by":1,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":907094,"visible":true,"origin":"","legend":"","description":"","filename":"6BIOcorrectspathophysiologyinSyngap1miceVermaetal.pdf","url":"https://assets-eu.researchsquare.com/files/rs-682039/v1_covered.pdf"},{"id":11163474,"identity":"407fc1cd-ab6f-49d8-9d23-e62cdbc030a3","added_by":"auto","created_at":"2021-07-06 16:43:43","extension":"pdf","order_by":1,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":903503,"visible":true,"origin":"","legend":"","description":"","filename":"6BIOcorrectspathophysiologyinSyngap1miceVermaetal.pdf","url":"https://assets-eu.researchsquare.com/files/rs-682039/v1_covered.pdf"},{"id":11163448,"identity":"f9e1199c-9bc0-41d9-9c64-2011b5cff3e4","added_by":"auto","created_at":"2021-07-06 16:43:28","extension":"pdf","order_by":1,"title":"","display":"","copyAsset":false,"role":"supplement","size":460725,"visible":true,"origin":"","legend":"SI: Reversing GABA polarity corrects synaptic physiology and behavioural deficits in young adolescent Syngap1+/- mice","description":"","filename":"SI6biocorrectspathophysiologyVermaClementetal.pdf","url":"https://assets-eu.researchsquare.com/files/rs-682039/v1/7d83afae5d87c51c9308d135.pdf"}],"financialInterests":"","formattedTitle":"\u003cp\u003eReversing GABA polarity corrects synaptic physiology and behavioural deficits in young adolescent \u003cem\u003eSyngap1\u003c/em\u003e\u003csup\u003e\u003cem\u003e+/-\u003c/em\u003e\u003c/sup\u003e mice\u003c/p\u003e","fulltext":[{"header":"Full Text","content":"This preprint is available for \u003ca href='/article/rs-682039/latest.pdf' target='_blank'\u003edownload as a PDF\u003c/a\u003e."}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":false,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":true,"hideJournal":true,"highlight":"","institution":"Jawaharlal Nehru Centre for Advanced Scientific Research","isAcceptedByJournal":false,"isAuthorSuppliedPdf":true,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"Autism spectrum disorder, Intellectual disability, Syngap1 heterozygous mutation, GABA, NKCC1, KCC2, GSK-3β","lastPublishedDoi":"10.21203/rs.3.rs-682039/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-682039/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eHaploinsufficiency in \u003cem\u003eSYNGAP1\u003c/em\u003e is implicated in Intellectual Disability (ID) and Autism Spectrum disorder (ASD) and affects the maturation of dendritic spines. The abnormal spine development has been suggested to cause disbalance of excitatory and inhibitory (E/I) neurotransmission at distinct developmental periods. In addition, E/I imbalances in \u003cem\u003eSyngap1\u003c/em\u003e\u003csup\u003e\u003cem\u003e+/-\u003c/em\u003e\u003c/sup\u003e mice might be due to abnormalities in K\u003csup\u003e+\u003c/sup\u003e-Cl\u003csup\u003e-\u003c/sup\u003e co-transporter function (NKCC1, KCC2), in a similar manner as in the murine models of Fragile-X and Rett syndromes. To study whether an altered intracellular chloride ion concentration represents an underlying mechanism of altered function of GABAergic synapses in Dentate Gyrus Granule Cells\u003cem\u003e \u003c/em\u003eof \u003cem\u003eSyngap1\u003c/em\u003e\u003csup\u003e\u003cem\u003e+/-\u003c/em\u003e\u003c/sup\u003e recordings were performed at different developmental stages of the mice. We observed that neurons at P14-15 of \u003cem\u003eSyngap1\u003c/em\u003e\u003csup\u003e\u003cem\u003e+/-\u003c/em\u003e\u003c/sup\u003e\u003cem\u003e \u003c/em\u003emice had depolarised membrane potential and a decreased Cl\u003csup\u003e-\u003c/sup\u003e reversal potential. The KCC2 expression was decreased compared to Wild-type (WT) mice at P14-15. Furtherly, the small molecule GSK-3β inhibitor, 6-bromoindirubin-3`-oxime (6BIO), was tested in an attempt to restore the function of GABAergic synapses. We discovered that intraperitoneal administration of 6BIO during the critical period or young adolescents normalized an altered E/I balance, the deficits of synaptic transmission, and behavioral performance like social novelty, anxiety, and memory of the \u003cem\u003eSyngap1\u003c/em\u003e\u003csup\u003e\u003cem\u003e+/-\u003c/em\u003e\u003c/sup\u003e\u003cem\u003e \u003c/em\u003emice. In summary, altered functionality of GABAergic synapses in \u003cem\u003eSyngap1\u003c/em\u003e\u003csup\u003e\u003cem\u003e+/-\u003c/em\u003e\u003c/sup\u003e\u003cem\u003e \u003c/em\u003emice is based on a reduced KCC2 expression and a subsequent increase in the intracellular chloride concentration that can be counteracted by the small molecule 6BIO. The 6BIO sufficiently restored cognitive, emotional, and social symptoms by pharmacological intervention, particularly, in adulthood.\u003c/p\u003e\u003cp\u003e\u003cbr\u003e\u003c/p\u003e","manuscriptTitle":"Reversing GABA polarity corrects synaptic physiology and behavioural deficits in young adolescent Syngap1+/- mice","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2021-07-06 16:40:26","doi":"10.21203/rs.3.rs-682039/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"4128cb1c-c002-449a-abd6-98543e8efa96","owner":[],"postedDate":"July 6th, 2021","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[{"id":5446130,"name":"Neurobiology of Disease"},{"id":5446131,"name":"Cellular \u0026 Molecular Neuroscience"}],"tags":[],"updatedAt":"2021-07-06T16:40:26+00:00","versionOfRecord":[],"versionCreatedAt":"2021-07-06 16:40:26","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-682039","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-682039","identity":"rs-682039","version":["v1"]},"buildId":"rHA-KDH7Qsr4HCuvH75dn","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}