Hippocampal Subregion Function and Its Clinical Correlations in Childhood Autism Spectrum Disorders.

This brain imaging study looked at memory-related brain areas (hippocampus) in 507 boys - 225 with autism and 282 without. Children with autism showed different brain connection patterns in these areas. The front part of the hippocampus connected differently to social and emotional brain regions, while the back part connected differently to visual and movement areas. These connection differences related to specific autism traits like social challenges and repetitive behaviors, and also linked to when symptoms first appeared.

This neuroimaging study analyzed hippocampal brain connectivity in 507 male children (225 with autism, 282 controls) using resting-state functional MRI. Researchers divided the hippocampus into front (rostral) and back (caudal) sections and found altered connectivity patterns in autism. Children with autism showed enhanced connectivity between hippocampal subregions and various brain networks including visual, motor, and cerebellar areas. Different hippocampal regions correlated with specific autism symptoms: social awareness linked to right caudal connections with face-processing areas, while repetitive behaviors connected to frontal and motor regions.

Age of symptom onset correlated with connectivity strength across all hippocampal subregions, suggesting developmental timing differences.

Findings suggest hippocampal subregions contribute differently to autism symptoms, with anterior regions more involved in social-emotional processing and posterior regions in sensorimotor integration. This subregional specificity could inform targeted interventions and help predict symptom profiles based on connectivity patterns.

Study limited to male participants only, reducing generalizability to females with autism. Machine learning classification achieved only modest performance. Cross-sectional design prevents conclusions about causation or developmental trajectories. Resting-state connectivity may not reflect task-based functional differences.

The hippocampus plays a crucial role in memory and social processing, both of which are impaired in autism spectrum disorder (ASD). Investigating the functional activity of hippocampal subregions can provide valuable insights into their involvement in ASD-related social and behavioral symptoms. This study analyzed hippocampal resting-state functional connectivity (rsFC) in 507 male child participants from the ABIDE dataset (225 ASD, 282 typical controls) and its relation to clinical features. The hippocampus was subdivided into rostral and caudal subregions, and rsFC patterns were compared between groups.

Significant group differences were observed in the left caudal, right rostral, and right caudal hippocampus, with enhanced connectivity to widespread cortical and subcortical regions, including visual, motor, parietal, and cerebellar networks. Machine learning using hippocampal rsFC achieved modest classification performance. Clinically, rsFC correlated with core ASD symptoms: social awareness was associated with right caudal connectivity to fusiform and temporal regions, while restricted and repetitive behaviors were linked to distinct rostral-caudal patterns involving frontal, motor, and cerebellar areas. Age of onset showed positive correlations with rsFC across all subregions, with rostral hippocampus engaging socioemotional and motor control networks and caudal hippocampus connecting more strongly to visual and sensorimotor integration regions.

These findings demonstrate subregional specificity of hippocampal connectivity in ASD, suggesting distinct anterior-posterior contributions to symptom expression and developmental timing.