Altered striosome-matrix distribution and activity of striatal cholinergic interneurons in a model of autism-linked repetitive behaviors

Abstract

Repetitive behaviors are cardinal features of many brain disorders, including autism spectrum disorder (ASD). We previously associated dysfunction of striatal cholinergic interneurons (SCINs) with repetitive behaviors in a mouse model based on conditional deletion of the ASD-related gene Tshz3 in cholinergic neurons (Chat-cKO). Here, we provide evidence linking SCIN abnormalities to the unique organization of the striatum into striosome and matrix compartments, whose imbalances are implicated in several pathological conditions. Chat-cKO mice exhibit an altered relationship between the embryonic birthdate of SCINs and their adult striosome-matrix distribution, leading to an increased proportion of striosomal SCINs. In addition, the ratio of striosomal SCINs with slow-irregular vs. sustained-regular firing is increased, which translates into decreased activity, further stressing the striosome-matrix imbalance. These findings provide novel insights into the pathogenesis of ASD-related stereotyped behaviors by pointing to abnormal developmental compartmentalization and activity of SCINs as a substrate.