Altered Development of Amygdala-Connected Brain Regions in Males and Females with Autism.

Researchers studied brain development in autistic children from ages 3-11 years using MRI scans. They found that brain areas connected to the amygdala (a region important for emotions and social behavior) develop differently in autism. These differences became more noticeable over time and were strongest in children with more severe social challenges. Boys and girls showed different patterns of brain changes, suggesting autism may affect the brain differently based on sex.

This longitudinal neuroimaging study examined brain development in autism across early to middle childhood. Researchers analyzed 950 MRI scans from 410 children (282 with autism, 128 typically developing) across multiple time points. The study focused on brain regions directly connected to the amygdala, finding persistent and increasing volumetric differences between autistic and typically developing children. These differences were most pronounced in autistic children with greater social impairments at baseline.

Notably, sex differences emerged: males showed greatest alterations in bilateral subgenual anterior cingulate cortices, while females showed changes in left fusiform and superior temporal gyri. The findings suggest autism involves widespread developmental alterations in amygdala-connected brain networks, with sex-specific patterns that correlate with social functioning severity.

Findings suggest amygdala-connected brain networks may serve as biomarkers for autism severity and developmental trajectories. Sex-specific patterns indicate need for personalized assessment approaches. The correlation between brain differences and social functioning supports targeted interventions for social skills development, particularly in early childhood when differences are emerging.

Study type not specified in provided metadata. Potential limitations may include sample characteristics, imaging methodology, or analysis approaches, but these cannot be determined from the abstract alone. The relationship between volumetric differences and functional outcomes requires further investigation.

Altered amygdala development is implicated in the neurobiology of autism, but little is known about the coordinated development of the brain regions directly connected with the amygdala. Here we investigated the volumetric development of an amygdala-connected network, defined as the set of brain regions with monosynaptic connections with the amygdala, in autism from early to middle childhood. A total of 950 longitudinal structural MRI scans were acquired from 282 children (93 female) with autism and 128 children with typical development (61 female) at up to four time points (mean ages: 39, 52, 64, and 137 months, respectively). Volumes from 32 amygdala-connected brain regions were examined using mixed effects multivariate distance matrix regression.

The Social Responsiveness Scale-2 was administered to assess degree of autistic traits and social impairments. The amygdala-connected network exhibited persistent diagnostic differences (values ≤ 0.03) that increased over time (values ≤ 0.02). These differences were most prominent in autistics with more impacted social functioning at baseline. This pattern was not observed across regions without monosynaptic amygdala connection.

We observed qualitative sex differences. In males, the bilateral subgenual anterior cingulate cortices were most affected, while in females the left fusiform and superior temporal gyri were most affected. In conclusion, (1) autism is associated with widespread alterations to the development of brain regions connected with the amygdala, which were associated with autistic social behaviors; and (2) autistic males and females exhibited different patterns of alterations, adding to a growing body of evidence of sex differences in the neurobiology of autism.Global patterns of development across brain regions with monosynaptic connection to the amygdala differentiate autism from typical development, and are modulated by social functioning in early childhood. Alterations to brain regions within the amygdala-connected network differed in males and females with autism.

Results also indicate larger volumetric differences in regions having monosynaptic connection with the amygdala than in regions without monosynaptic connection.