Castets, F. | Search bioRxiv

bioRxiv2024

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

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 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 onto the pathogenesis of ASD-related stereotyped behaviors by pointing to abnormal developmental compartmentalization and activity of SCINs as a substrate.

neuroscience↗

bioRxiv2023

Gut microbiota promotes pain chronicity in Myosin1A deficient male mice

Over the past decade, the gut microbiota has emerged as an important regulator of nervous systems health and disease states1. Yet, its contribution to the pathogenesis of chronic somatic pain remains poorly documented. Chronic pain is a heavily debilitating disease affecting more than 1.5 billion people worldwide that can manifest through a long-lasting hypersensitivity to mechanical and/or thermal stimulations2,3. Maladaptive responses of dorsal root ganglia (DRG) neurons and spinal cord (SC) interneurons to tissue injuries and also of non-neuronal cells including DRG macrophages and SC microglia are acknowledged as important drivers of sensory symptoms underlying chronic pain4,3,5-7. Recent evidence shows that signals from gut microbiota are required for the initiation of injury-induced sensory hypersensitivity, via the ability to interact with the immune system8-11. However, whether and how gut microbiota promotes pain chronicity remains unknown. Here, we report that male mice lacking Myosin1a (KO)12 raised under single genotype housing conditions (KO-SGH) are predisposed to develop chronic injury-induced mechanical pain. We demonstrate that this predisposition is caused by their dysbiotic gut microbiota, which sustains the immune response in the DRG following neuropathic injury. Parental antibiotic treatment modifies gut microbiota composition and completely rescues the injury-induced chronic pain and associated DRG inflammatory response in male KO-SGH offspring. Together, our data establish a causal relationship between a dysbiotic gut microbiota and the predisposition to injury-induced chronic pain.

neuroscience↗