Layer-Specific Changes in the Prefrontal Glia/Neuron Ratio Characterizes Patches of Gene Expression Disorganization in Children with Autism.

Scientists studied brain tissue from children with autism to understand how brain cells are organized. They found that in children with autism, there were fewer support cells (called glial cells) compared to nerve cells in a brain region important for thinking and planning. This difference was especially noticeable in certain patches and layers of brain tissue. These changes may help explain how autism affects brain development and function.

This postmortem brain study examined cellular organization in the prefrontal cortex of 11 children with autism compared to 11 non-autistic children. Researchers analyzed the ratio of glial cells to neurons (glia/neuron ratio) across different brain layers, focusing on patches of gene expression disruption previously identified in autism. The study found an overall reduced glia/neuron ratio in the autism group's dorsolateral prefrontal cortex. Additionally, layers II-III within patches showed lower ratios compared to layers V-VI.

These findings provide new insights into how brain cells are arranged within patches of disrupted gene expression, contributing to understanding altered neurodevelopmental programs in autism.

These cellular organization differences may inform understanding of autism neurobiology but cannot currently guide clinical practice. Findings contribute to research on cortical development in autism and may eventually inform biomarker development or therapeutic targets focusing on glial function.

Small sample size of 22 children total. Postmortem tissue analysis cannot establish causation or developmental timing. Unclear methodology details and statistical analyses. Cannot determine if findings represent cause or consequence of autism.

Autism spectrum disorder (ASD) is manifested by abnormal cell numbers and patches of gene expression disruption in higher-order brain regions. Here, we investigated whether layer-specific changes in glia/neuron ratios (GNR) characterize patches in the dorsolateral prefrontal cortex (DL-PFC) of children with ASD. We analyzed high-resolution digital images of postmortem human brains from 11 ASD and 11 non-ASD children obtained from the Autism Study of the Allen Human Brain Atlas. We found the GNR is overall reduced in the ASD DL-PFC.

Moreover, layers II-III belonging to patches presented a lower GNR in comparison with layers V-VI. We here provide a new insight into how brain cells are arranged within patches that contributes to elucidate how neurodevelopmental programs are altered in ASD.