Dysfunction of Trio GEF1 involves in excitatory/inhibitory imbalance and autism-like behaviors through regulation of interneuron migration.

Autism spectrum disorders (ASDs) are a group of highly inheritable neurodevelopmental disorders. Functional mutations in TRIO, especially in the GEF1 domain, are strongly implicated in ASDs, whereas the underlying neurobiological pathogenesis and molecular mechanisms remain to be clarified. Here we characterize the abnormal morphology and behavior of embryonic migratory interneurons (INs) upon Trio deficiency or GEF1 mutation in mice, which are mediated by the Trio GEF1-Rac1 activation and involved in SDF1α/CXCR4 signaling. In addition, the migration deficits are specifically associated with altered neural microcircuit, decreased inhibitory neurotransmission, and autism-like behaviors, which are reminiscent of some features observed in patients with ASDs. Furthermore, restoring the excitatory/inhibitory (E/I) imbalance via activation of GABA signaling rescues autism-like deficits. Our findings demonstrate a critical role of Trio GEF1 mediated signaling in IN migration and E/I balance, which are related to autism-related behavioral phenotypes.