The striatal matrix compartment is expanded in autism spectrum disorder

Area of Science:

• Neuroscience
• Developmental Neuroscience
• Neuroanatomy

Background:

• Autism spectrum disorder (ASD) is a common neurodevelopmental disorder characterized by social, communication, and behavioral challenges.
• The striatum, a critical brain region, shows structural and functional abnormalities in ASD.
• The striatum comprises distinct matrix and striosome compartments, and their altered ratio is implicated in ASD.

Purpose of the Study:

• To investigate the structural connectivity patterns of striatal compartments in individuals with ASD.
• To determine if matrix:striosome volume ratios are altered in ASD using in vivo neuroimaging.

Main Methods:

• A cohort of 426 children and adults (213 ASD-control pairs) was studied.
• Connectivity-based parcellation using diffusion tractography was employed to map matrix-like and striosome-like striatal voxels.
• Autism Diagnostic Observation Schedule (ADOS) scores were correlated with striatal compartment volumes.

Main Results:

• Individuals with ASD exhibited significantly increased matrix-like striatal volume compared to controls.
• The striosome-like compartment showed no significant changes in volume or organization.
• A 31% larger inter-compartment volume difference (matrix minus striosome) was observed in ASD, with greater increases in matrix-like volume correlating with higher ADOS scores.

Conclusions:

• Increased matrix-like striatal volume is a key neuroanatomical finding in ASD.
• Compartment-specific abnormalities in the striatum may contribute to the diverse clinical features of ASD.
• In vivo striatal parcellation offers a novel method for assessing neuropsychiatric diseases.