Specific Association Patterns Between Brain Glutathione Levels, Myelination, and Functional Connectivity in Adults With Autism Spectrum Disorder.

Researchers studied brain chemistry and connections in 57 adults (30 with autism, 27 without). They found that people with autism had higher levels of an important brain antioxidant called glutathione in one brain region, opposite to what was expected. The brain regions also connected differently in people with autism, especially areas involved in social thinking and emotion recognition. This suggests the autistic brain may use different strategies to function effectively.

This neuroimaging study examined brain glutathione (GSH) levels, myelination, and functional connectivity in 30 adults with ASD compared to 27 typically developing adults. Contrary to expectations based on postmortem studies, GSH levels in the temporoparietal junction were higher in the ASD group. The research revealed ASD-specific association patterns between left temporoparietal junction GSH levels, left middle frontal gyrus myelination, and whole-brain functional connectivity. Additionally, emotion recognition ability showed different correlations with functional connectivity patterns between groups.

These findings suggest compensatory neural mechanisms may be operating in ASD, representing a novel perspective on oxidative stress and brain function in autism.

Results suggest compensatory neural mechanisms in ASD rather than simple deficits. May inform future therapeutic approaches targeting oxidative stress pathways. Highlights importance of considering individual variation in brain chemistry and connectivity patterns when developing interventions for adults with ASD.

Single study with relatively small sample size (57 participants). Cross-sectional design prevents determination of causality. Limited to adult population only. Findings contradict previous postmortem studies, requiring replication to confirm results.

Recent studies have implicated oxidative stress in the pathophysiology of autism spectrum disorder (ASD). Postmortem brain studies have revealed decreased levels of the reduced form of glutathione (GSH), an important antioxidant, in some brain regions in individuals with ASD; however, in vivo evidence is lacking. Using proton magnetic resonance spectroscopy, T-weighted/T-weighted ratio-derived myelin maps, resting-state functional magnetic resonance imaging (MRI), and cognitive tasks, we examined whether brain GSH levels are lower in individuals with ASD than in those with typical development (TD) and explored ASD-specific association patterns between brain GSH levels, myelination, functional connectivity, and behavioral characteristics. Data from 30 adults with ASD and 27 adults with TD were analyzed.

Contrary to our hypothesis, GSH levels in the left temporoparietal junction (TPJ) were higher in the ASD group than in the TD group. Using individual myelin maps, we found a significant group difference in the correlation between left middle frontal gyrus (MFG) myelination and left TPJ GSH levels. Multivariate pattern analysis of resting-state functional MRI revealed that whole-brain functional connectivity patterns from the left MFG differed between the groups in their association with left MFG myelination. Finally, we found a significant group difference in the correlation between emotion recognition ability and the functional connectivity of the left MFG with the bilateral occipitoparietal junction.

In conclusion, our findings demonstrate an ASD-specific pattern of associations between left TPJ GSH levels, left MFG myelination, whole-brain functional connectivity patterns of the left MFG, and cognitive phenotype, which suggests compensatory neural mechanisms in ASD.