Abstract

Autism spectrum disorder is a neurodevelopmental disease characterized by social deficits and repetitive behaviors. The high heterogeneity of the disease may be explained by gene and environmental interactions and potential risk factors include immune dysfunctions and immune-mediated co-morbidities. Mutations in the SHANK3 gene have been recognized as a genetic risk factor for ASD. While heterozygous SHANK3 mutations are usually the types of mutations associated with idiopathic autism in patients, heterozygous deletion of Shank3 gene in mice does not commonly induce ASD-related behavioural deficit. Here, we used in-vivo and ex-vivo approaches to demonstrate that region-specific neonatal downregulation of Shank3 in the NAc promotes D1R-MSN hyperexcitability and upregulates Trpv4 to impair social behaviour. Interestingly, genetically vulnerable Shank3+/- mice, when challenged with Lipopolysaccharide to induce inflammatory response, showed similar circuit and behavioural alterations that were rescued by acute Trpv4 inhibition. Altogether our data demonstrate shared molecular and circuit mechanisms between ASD-relevant genetic alterations and environmental insults, which ultimately lead to sociability dysfunctions.