1Brain Nerve 2008 Apr 60: 445-52
Title[Neurodevelopmental disturbance in the pathogenesis of major mental disorders].
AbstractNeurodevelopmental disturbance may underlie the pathogenesis of major mental disorders, including autism and schizophrenia, based on evidence in epidemiology, clinical psychiatry, brain imaging, and neuropathology. This notion is further supported by the fact that many of genetic susceptibility factors for these disorders have key roles in neurodevelopment. Majority of these genetic factors, such as Neuroligins, SHANK3, Neureglin-1, Dysbindin, and Disrupted-in-schizophrenia-1 (DISC1) are associated with "synapse." Therefore, "synapse" is one of the most promising sites of convergence in regard to molecular pathways for these mental conditions. In this review, we will summarize the updates of schizophrenia and autism research, with an emphasis on neurodevelopmental disturbances.
SCZ Keywordsschizophrenia
2Proc. Natl. Acad. Sci. U.S.A. 2010 Apr 107: 7863-8
TitleDe novo mutations in the gene encoding the synaptic scaffolding protein SHANK3 in patients ascertained for schizophrenia.
Abstractschizophrenia likely results from poorly understood genetic and environmental factors. We studied the gene encoding the synaptic protein SHANK3 in 285 controls and 185 schizophrenia patients with unaffected parents. Two de novo mutations (R1117X and R536W) were identified in two families, one being found in three affected brothers, suggesting germline mosaicism. Zebrafish and rat hippocampal neuron assays revealed behavior and differentiation defects resulting from the R1117X mutant. As mutations in SHANK3 were previously reported in autism, the occurrence of SHANK3 mutations in subjects with a schizophrenia phenotype suggests a molecular genetic link between these two neurodevelopmental disorders.
SCZ Keywordsschizophrenia
3Mol Autism 2011 -1 2: 9
TitleGene expression analysis in lymphoblasts derived from patients with autism spectrum disorder.
AbstractThe autism spectrum disorders (ASDs) are complex neurodevelopmental disorders that result in severe and pervasive impairment in the development of reciprocal social interaction and verbal and nonverbal communication skills. In addition, individuals with ASD have stereotypical behavior, interests and activities. Rare mutations of some genes, such as neuroligin (NLGN) 3/4, neurexin (NRXN) 1, SHANK3, MeCP2 and NHE9, have been reported to be associated with ASD. In the present study, we investigated whether alterations in mRNA expression levels of these genes could be found in lymphoblastoid cell lines derived from patients with ASD.
We measured mRNA expression levels of NLGN3/4, NRXN1, SHANK3, MeCP2, NHE9 and AKT1 in lymphoblastoid cells from 35 patients with ASD and 35 healthy controls, as well as from 45 patients with schizophrenia and 45 healthy controls, using real-time quantitative reverse transcriptase polymerase chain reaction assays.
The mRNA expression levels of NLGN3 and SHANK3 normalized by ?-actin or TBP were significantly decreased in the individuals with ASD compared to controls, whereas no difference was found in the mRNA expression level of MeCP2, NHE9 or AKT1. However, normalized NLGN3 and SHANK3 gene expression levels were not altered in patients with schizophrenia, and expression levels of NLGN4 and NRXN1 mRNA were not quantitatively measurable in lymphoblastoid cells.
Our results provide evidence that the NLGN3 and SHANK3 genes may be differentially expressed in lymphoblastoid cell lines from individuals with ASD compared to those from controls. These findings suggest the possibility that decreased mRNA expression levels of these genes might be involved in the pathophysiology of ASD in a substantial population of ASD patients.
SCZ Keywordsschizophrenia
4PLoS ONE 2012 -1 7: e37385
TitleGenetic copy number variation and general cognitive ability.
AbstractDifferences in genomic structure between individuals are ubiquitous features of human genetic variation. Specific copy number variants (CNVs) have been associated with susceptibility to numerous complex psychiatric disorders, including attention-deficit-hyperactivity disorder, autism-spectrum disorders and schizophrenia. These disorders often display co-morbidity with low intelligence. Rare chromosomal deletions and duplications are associated with these disorders, so it has been suggested that these deletions or duplications may be associated with differences in intelligence. Here we investigate associations between large (?500kb), rare (<1% population frequency) CNVs and both fluid and crystallized intelligence in community-dwelling older people. We observe no significant associations between intelligence and total CNV load. Examining individual CNV regions previously implicated in neuropsychological disorders, we find suggestive evidence that CNV regions around SHANK3 are associated with fluid intelligence as derived from a battery of cognitive tests. This is the first study to examine the effects of rare CNVs as called by multiple algorithms on cognition in a large non-clinical sample, and finds no effects of such variants on general cognitive ability.
SCZ Keywordsschizophrenia
5Eur Arch Psychiatry Clin Neurosci 2012 Mar 262: 117-24
TitleA promoter variant of SHANK1 affects auditory working memory in schizophrenia patients and in subjects clinically at risk for psychosis.
AbstractMutations in postsynaptic scaffolding genes contribute to autism, thus suggesting a role in pathological processes in neurodevelopment. Recently, two de novo mutations in SHANK3 were described in schizophrenia patients. In most cases, abnormal SHANK3 genotype was also accompanied by cognitive disruptions. The present study queries whether common SHANK variants may also contribute to neuropsychological dysfunctions in schizophrenia. We genotyped five common coding or promoter variants located in SHANK1, SHANK2 and SHANK3. A comprehensive test battery was used to assess neuropsychological functions in 199 schizophrenia patients and 206 healthy control subjects. In addition, an independent sample of 77 subjects at risk for psychosis was analyzed for replication of significant findings. We found the T allele of the SHANK1 promoter variant rs3810280 to lead to significantly impaired auditory working memory as assessed with digit span (12.5 ± 3.6 vs. 14.8 ± 4.1, P < .001) in schizophrenia cases, applying strict Bonferroni correction for multiple testing. This finding was replicated for forward digit span in the at-risk sample (7.1 ± 2.0 vs. 8.3 ± 2.0, P = .044). Previously, altered memory functions and reduced dendritic spines and postsynaptic density of excitatory synapses were reported in SHANK1 knock-out mice. Moreover, the atypical neuroleptic clozapine was found to increase SHANK1 density in rats. Our findings suggest a role of SHANK1 in working memory deficits in schizophrenia, which may arise from neurodevelopmental changes to prefrontal cortical areas.
SCZ Keywordsschizophrenia
6Eur J Med Genet 2012 Nov 55: 625-9
TitleBipolar affective disorder and early dementia onset in a male patient with SHANK3 deletion.
AbstractThe SHANK3 protein is a scaffold protein known to stabilize metabotropic glutamate receptor mGluR5 in the post-synaptic membrane of neurons. It is associated with genetic vulnerability in autism and schizophrenia. Here we report the case of an 18 year-old male patient who displayed psychiatric features of bipolar affective disorder associated with early setting of dementia. This mental status is related to sporadic occurrence of SHANK3 gene complex multiple deletions. A low beta amyloid protein rate (479 mg/L) found in cerebrospinal fluid suggests a possible link between SHANK3 deletion syndrome-associated regression and dementia of Alzheimers's type. In addition, we propose an overview of the phenotype related to SHANK3 deletion.
SCZ Keywordsschizophrenia
7Mol. Psychiatry 2012 Jan 17: 71-84
TitleSHANK3 mutations identified in autism lead to modification of dendritic spine morphology via an actin-dependent mechanism.
AbstractGenetic mutations of SHANK3 have been reported in patients with intellectual disability, autism spectrum disorder (ASD) and schizophrenia. At the synapse, SHANK3/ProSAP2 is a scaffolding protein that connects glutamate receptors to the actin cytoskeleton via a chain of intermediary elements. Although genetic studies have repeatedly confirmed the association of SHANK3 mutations with susceptibility to psychiatric disorders, very little is known about the neuronal consequences of these mutations. Here, we report the functional effects of two de novo mutations (STOP and Q321R) and two inherited variations (R12C and R300C) identified in patients with ASD. We show that SHANK3 is located at the tip of actin filaments and enhances its polymerization. SHANK3 also participates in growth cone motility in developing neurons. The truncating mutation (STOP) strongly affects the development and morphology of dendritic spines, reduces synaptic transmission in mature neurons and also inhibits the effect of SHANK3 on growth cone motility. The de novo mutation in the ankyrin domain (Q321R) modifies the roles of SHANK3 in spine induction and morphology, and actin accumulation in spines and affects growth cone motility. Finally, the two inherited mutations (R12C and R300C) have intermediate effects on spine density and synaptic transmission. Therefore, although inherited by healthy parents, the functional effects of these mutations strongly suggest that they could represent risk factors for ASD. Altogether, these data provide new insights into the synaptic alterations caused by SHANK3 mutations in humans and provide a robust cellular readout for the development of knowledge-based therapies.
SCZ Keywordsschizophrenia
8Nature 2013 Nov 503: 267-71
TitleSHANK3 and IGF1 restore synaptic deficits in neurons from 22q13 deletion syndrome patients.
AbstractPhelan-McDermid syndrome (PMDS) is a complex neurodevelopmental disorder characterized by global developmental delay, severely impaired speech, intellectual disability, and an increased risk of autism spectrum disorders (ASDs). PMDS is caused by heterozygous deletions of chromosome 22q13.3. Among the genes in the deleted region is SHANK3, which encodes a protein in the postsynaptic density (PSD). Rare mutations in SHANK3 have been associated with idiopathic ASDs, non-syndromic intellectual disability, and schizophrenia. Although SHANK3 is considered to be the most likely candidate gene for the neurological abnormalities in PMDS patients, the cellular and molecular phenotypes associated with this syndrome in human neurons are unknown. We generated induced pluripotent stem (iPS) cells from individuals with PMDS and autism and used them to produce functional neurons. We show that PMDS neurons have reduced SHANK3 expression and major defects in excitatory, but not inhibitory, synaptic transmission. Excitatory synaptic transmission in PMDS neurons can be corrected by restoring SHANK3 expression or by treating neurons with insulin-like growth factor 1 (IGF1). IGF1 treatment promotes formation of mature excitatory synapses that lack SHANK3 but contain PSD95 and N-methyl-D-aspartate (NMDA) receptors with fast deactivation kinetics. Our findings provide direct evidence for a disruption in the ratio of cellular excitation and inhibition in PMDS neurons, and point to a molecular pathway that can be recruited to restore it.
SCZ Keywordsschizophrenia
9Neuron 2014 Aug 83: 894-905
TitleSensory integration in mouse insular cortex reflects GABA circuit maturation.
AbstractInsular cortex (IC) contributes to a variety of complex brain functions, such as communication, social behavior, and self-awareness through the integration of sensory, emotional, and cognitive content. How the IC acquires its integrative properties remains unexplored. We compared the emergence of multisensory integration (MSI) in the IC of behaviorally distinct mouse strains. While adult C57BL/6 mice exhibited robust MSI, this capacity was impaired in the inbred BTBR T+tf/J mouse model of idiopathic autism. The deficit reflected weakened ?-aminobutyric acid (GABA) circuits and compromised postnatal pruning of cross-modal input. Transient pharmacological enhancement by diazepam in BTBR mice during an early sensitive period rescued inhibition and integration in the adult IC. Moreover, impaired MSI was common across three other monogenic models (GAD65, SHANK3, and Mecp2 knockout mice) displaying behavioral phenotypes and parvalbumin-circuit abnormalities. Our findings offer developmental insight into a key neural circuit relevant to neuropsychiatric conditions like schizophrenia and autism.
SCZ Keywordsschizophrenia
10Front Cell Neurosci 2014 -1 8: 87
TitleSarm1 deficiency impairs synaptic function and leads to behavioral deficits, which can be ameliorated by an mGluR allosteric modulator.
AbstractInnate immune responses have been shown to influence brain development and function. Dysregulation of innate immunity is significantly associated with psychiatric disorders such as autism spectrum disorders and schizophrenia, which are well-known neurodevelopmental disorders. Recent studies have revealed that critical players of the innate immune response are expressed in neuronal tissues and regulate neuronal function and activity. For example, Sarm1, a negative regulator that acts downstream of Toll-like receptor (TLR) 3 and 4, is predominantly expressed in neurons. We have previously shown that Sarm1 regulates neuronal morphogenesis and the expression of inflammatory cytokines in the brain, which then affects learning ability, cognitive flexibility, and social interaction. Because impaired neuronal morphogenesis and dysregulation of cytokine expression may disrupt neuronal activity, we investigated whether Sarm1 knockdown affects the synaptic responses of neurons. We here show that reduced Sarm1 expression impairs metabotropic glutamate receptor (mGluR)-dependent long-term depression (LTD) formation but enhances N-methyl-D-aspartate receptor (NMDAR)-dependent long-term potentiation production in hippocampal CA1 neurons. The expression levels of post-synaptic proteins, including NR2a, NR1, Shank1 and SHANK3, are also altered in Sarm1 knockdown mice, suggesting a role for Sarm1 in the maintenance of synaptic homeostasis. The addition of a positive allosteric modulator of mGluR5, CDPPB, ameliorates the LTD defects in slice recording and the behavioral deficits in social interaction and associative memory. These results suggest an important role for mGluR5 signaling in the function of Sarm1. In conclusion, our study demonstrates a role for Sarm1 in the regulation of synaptic plasticity. Through these mechanisms, Sarm1 knockdown results in the impairment of associative memory and social interactions in mice.
SCZ Keywordsschizophrenia
11Exp. Neurol. 2014 Mar 253: 126-37
TitleThe PSD protein ProSAP2/Shank3 displays synapto-nuclear shuttling which is deregulated in a schizophrenia-associated mutation.
AbstractRecently, mutations in ProSAP2/SHANK3 have been discovered as one of the genetic factors for schizophrenia (SCZ). Here, we show that the postsynaptic density protein ProSAP2/SHANK3 undergoes activity dependent synapse-to-nucleus shuttling in hippocampal neurons. Our study shows that the de novo mutation (R1117X) in ProSAP2/SHANK3 that was identified in a patient with SCZ leads to an accumulation of mutated ProSAP2/SHANK3 within the nucleus independent of synaptic activity. Furthermore, we identified novel nuclear ProSAP2/SHANK3 interaction partners. Nuclear localization of mutated ProSAP2/SHANK3 alters transcription of several genes, among them already identified genetic risk factors for SCZ such as Synaptotagmin 1 and LRRTM1. Comparing the SCZ mutation of ProSAP2/SHANK3 to the knockdown of ProSAP2/SHANK3 we found some shared features such as reduced synaptic density in neuronal cultures. However, hippocampal neurons expressing the ProSAP2/SHANK3 SCZ mutation furthermore show altered E/I ratio and reduced dendritic branching. Thus, we conclude that the uncoupling of ProSAP2/SHANK3 nuclear shuttling from synaptic activity may represent a molecular mechanism that contributes to the pathology of SCZ in patients with mutations in ProSAP2/SHANK3.
SCZ Keywordsschizophrenia
12Dev Neurobiol 2014 Feb 74: 113-22
TitleThe emerging role of SHANK genes in neuropsychiatric disorders.
AbstractThe genetic heterogeneity of neuropsychiatric disorders is high, but some pathways emerged, notably synaptic functioning. A large number of mutations have been described in genes such as neuroligins, neurexins, and SHANK that play a role in the formation and the maintenance of synapses. This review focuses on the disorders associated with mutations in SHANK3 and the other members of its family, SHANK1 and SHANK2. SHANKs are scaffolding proteins of the postsynaptic density of glutamatergic synapses. SHANK3 has been described in the Phelan-McDermid syndrome (PMS), but also in autism spectrum disorders (ASD) and schizophrenia associated to moderate to severe intellectual disability (ID) and poor language. The evolution of patients with PMS includes symptoms of bipolar disorder and regression. SHANK2 has been identified in patients with ASD with mild to severe ID. SHANK1 has been associated with high-functioning autism in male patients, while carrier females only display anxiety and shyness. Finally, based on neuropathological findings in animal models and patients, a possible role of SHANK in Alzheimer's disease is discussed. Altogether, this review describes the clinical trajectories associated with different mutations of the SHANK genes and provides information to further investigate the role of the SHANK genes in neuropsychiatric disorders.
SCZ Keywordsschizophrenia
13Ann. Anat. 2015 Jul 200: 115-7
TitleTranslational neurobiology in Shank mutant mice--model systems for neuropsychiatric disorders.
AbstractThe Shank family comprises three core postsynaptic scaffold proteins of excitatory synapses in the mammalian brain: Shank1, Shank2 and SHANK3. Since mutations in all three human SHANK genes are linked to neuropsychiatric disorders such as autism and schizophrenia, Shank mutant mice serve as corresponding in vivo model systems. Besides intriguing alterations in behavior, dysfunction of glutamatergic synapses has emerged as a pathological hallmark among several Shank mutant lines. However, there is very limited knowledge of the underlying pathomechanisms. Therefore, precise neurobiological evaluation of morphological, molecular and electrophysiological phenotypes in Shank mutants is crucially needed. In this brief review, I will focus on the Shank mutant mouse lines we have generated so far and discuss how they might help us to develop translational treatment studies in the future.
SCZ Keywordsschizophrenia
14Mol. Psychiatry 2015 Apr 20: 424-32
TitleProteomic and genomic evidence implicates the postsynaptic density in schizophrenia.
AbstractThe postsynaptic density (PSD) contains a complex set of proteins of known relevance to neuropsychiatric disorders, and schizophrenia specifically. We enriched for this anatomical structure, in the anterior cingulate cortex, of 20 schizophrenia samples and 20 controls from the Stanley Medical Research Institute, and used unbiased shotgun proteomics incorporating label-free quantitation to identify differentially expressed proteins. Quantitative investigation of the PSD revealed more than 700 protein identifications and 143 differentially expressed proteins. Prominent among these were altered expression of proteins involved in clathrin-mediated endocytosis (CME) (Dynamin-1, adaptor protein 2) and N-methyl-D-aspartate (NMDA)-interacting proteins such as CYFIP2, SYNPO, SHANK3, ESYT and MAPK3 (all P<0.0015). Pathway analysis of the differentially expressed proteins implicated the cellular processes of endocytosis, long-term potentiation and calcium signaling. Both single-gene and gene-set enrichment analyses in genome-wide association data from the largest schizophrenia sample to date of 13,689 cases and 18,226 controls show significant association of HIST1H1E and MAPK3, and enrichment of our PSD proteome. Taken together, our data provide robust evidence implicating PSD-associated proteins and genes in schizophrenia, and suggest that within the PSD, NMDA-interacting and endocytosis-related proteins contribute to disease pathophysiology.
SCZ Keywordsschizophrenia
15Mol Brain 2015 -1 8: 74
TitlePost-transcriptional regulation of SHANK3 expression by microRNAs related to multiple neuropsychiatric disorders.
AbstractProper neuronal function requires tight control of gene dosage, and failure of this process underlies the pathogenesis of multiple neuropsychiatric disorders. The SHANK3 gene encoding core scaffolding proteins at glutamatergic postsynapse is a typical dosage-sensitive gene, both deletions and duplications of which are associated with Phelan-McDermid syndrome, autism spectrum disorders, bipolar disorder, intellectual disability, or schizophrenia. However, the regulatory mechanism of SHANK3 expression in neurons itself is poorly understood.
Here we show post-transcriptional regulation of SHANK3 expression by three microRNAs (miRNAs), miR-7, miR-34a, and miR-504. Notably, the expression profiles of these miRNAs were previously shown to be altered in some neuropsychiatric disorders which are also associated with SHANK3 dosage changes. These miRNAs regulated the expression of SHANK3 and other genes encoding actin-related proteins that interact with SHANK3, through direct binding sites in the 3' untranslated region (UTR). Moreover, overexpression or inhibition of miR-7 and miR-504 affected the dendritic spines of the cultured hippocampal neurons in a SHANK3-dependent manner. We further characterized miR-504 as it showed the most significant effect on both SHANK3 expression and dendritic spines among the three miRNAs. Lentivirus-mediated overexpression of miR-504, which mimics its reported expression change in postmortem brain tissues of bipolar disorder, decreased endogenous SHANK3 protein in cultured hippocampal neurons. We also revealed that miR-504 is expressed in the cortical and hippocampal regions of human and mouse brains.
Our study provides new insight into the miRNA-mediated regulation of SHANK3 expression, and its potential implication in multiple neuropsychiatric disorders associated with altered SHANK3 and miRNA expression profiles.
SCZ Keywordsschizophrenia
16J Clin Neurosci 2015 Aug 22: 1254-7
TitleMicroRNA-7/Shank3 axis involved in schizophrenia pathogenesis.
AbstractThis study aimed to identify the difference of microRNA-7 (miR-7) expression levels between schizophrenia patients and healthy controls and to investigate the regulatory effects of miR-7 on the SHANK3 gene in schizophrenia. miR-7 levels in plasma were detected by quantitative polymerase chain reactions (qPCR) in 50 schizophrenia patients and 50 healthy controls. The hippocampal neuron cell line, HT22, was transfected with lentiviral vector overexpressing or knocking-down miR-7, and the expression levels of SHANK3 mRNA and SHANK3 protein were measured by qPCR and immunofluorescence. A luciferase assay was carried out to analyze the regulatory effects of miR-7 on SHANK3. Circulating miR-7 level was significantly increased in schizophrenia patients (p = 0.022). Overexpression of miR-7 suppressed the expression of SHANK3 while the levels of SHANK3 mRNA and Shank protein were significantly increased by miR-7 knockdown. We conclude that miR-7 binds to 3-prime untranslated regions of SHANK3 mRNA and causes the alteration of neuronal morphology and function, potentially playing a crucial role in the pathophysiological process of schizophrenia.
SCZ Keywordsschizophrenia
17Neuron 2016 Jan 89: 147-62
TitleMice with Shank3 Mutations Associated with ASD and Schizophrenia Display Both Shared and Distinct Defects.
AbstractGenetic studies have revealed significant overlaps of risk genes among psychiatric disorders. However, it is not clear how different mutations of the same gene contribute to different disorders. We characterized two lines of mutant mice with SHANK3 mutations linked to ASD and schizophrenia. We found both shared and distinct synaptic and behavioral phenotypes. Mice with the ASD-linked InsG3680 mutation manifest striatal synaptic transmission defects before weaning age and impaired juvenile social interaction, coinciding with the early onset of ASD symptoms. On the other hand, adult mice carrying the schizophrenia-linked R1117X mutation show profound synaptic defects in prefrontal cortex and social dominance behavior. Furthermore, we found differential SHANK3 mRNA stability and SHANK1/2 upregulation in these two lines. These data demonstrate that different alleles of the same gene may have distinct phenotypes at molecular, synaptic, and circuit levels in mice, which may inform exploration of these relationships in human patients.
SCZ Keywordsschizophrenia
18Biol. Psychiatry 2016 Feb -1: -1
TitleReceptor Tyrosine Kinase MET Interactome and Neurodevelopmental Disorder Partners at the Developing Synapse.
AbstractAtypical synapse development and plasticity are implicated in many neurodevelopmental disorders (NDDs). NDD-associated, high-confidence risk genes have been identified, yet little is known about functional relationships at the level of protein-protein interactions, which are the dominant molecular bases responsible for mediating circuit development.
Proteomics in three independent developing neocortical synaptosomal preparations identified putative interacting proteins of the ligand-activated MET receptor tyrosine kinase, an autism risk gene that mediates synapse development. The candidates were translated into interactome networks and analyzed bioinformatically. Additionally, three independent quantitative proximity ligation assays in cultured neurons and four independent immunoprecipitation analyses of synaptosomes validated protein interactions.
Approximately 11% (8/72) of MET-interacting proteins, including SHANK3, SYNGAP1, and GRIN2B, are associated with NDDs. Proteins in the MET interactome were translated into a novel MET interactome network based on human protein-protein interaction databases. High-confidence genes from different NDD datasets that encode synaptosomal proteins were analyzed for being enriched in MET interactome proteins. This was found for autism but not schizophrenia, bipolar disorder, major depressive disorder, or attention-deficit/hyperactivity disorder. There is correlated gene expression between MET and its interactive partners in developing human temporal and visual neocortices but not with highly expressed genes that are not in the interactome. Proximity ligation assays and biochemical analyses demonstrate that MET-protein partner interactions are dynamically regulated by receptor activation.
The results provide a novel molecular framework for deciphering the functional relations of key regulators of synaptogenesis that contribute to both typical cortical development and to NDDs.
SCZ Keywordsschizophrenia
19Mol. Psychiatry 2016 Feb 21: 159-68
TitleMicro-electrode array recordings reveal reductions in both excitation and inhibition in cultured cortical neuron networks lacking Shank3.
AbstractNumerous risk genes have recently been implicated in susceptibility to autism and schizophrenia. Translating such genetic findings into disease-relevant neurobiological mechanisms is challenging due to the lack of throughput assays that can be used to assess their functions on an appropriate scale. To address this issue, we explored the feasibility of using a micro-electrode array (MEA) as a potentially scalable assay to identify the electrical network phenotypes associated with risk genes. We first characterized local and global network firing in cortical neurons with MEAs, and then developed methods to analyze the alternation between the network active period (NAP) and the network inactive period (NIP), each of which lasts tens of seconds. We then evaluated the electric phenotypes of neurons derived from SHANK3 knockout (KO) mice. Cortical neurons cultured on MEAs displayed a rich repertoire of spontaneous firing, and SHANK3 deletion led to reduced firing activity. Enhancing excitation with CX546 rescued the deficit in the spike rate in the SHANK3 KO network. In addition, the SHANK3 KO network produced a shorter NIP, and this altered network firing pattern was normalized by clonazepam, a positive modulator of the GABAA receptor. MEA recordings revealed electric phenotypes that displayed altered excitation and inhibition in the network lacking SHANK3. Thus, our study highlights MEAs as an experimental framework for measuring multiple robust neurobiological end points in dynamic networks and as an assay system that could be used to identify electric phenotypes in cultured neuronal networks and to analyze additional risk genes identified in psychiatric genetics.
SCZ Keywordsschizophrenia