Impact of environmental range size on hippocampal structure in chimpanzees

Motivation: Understanding how environmental factors influence hippocampal structure is critical for enhancing our knowledge of spatial cognitive adaptations in primates. Goal(s): This study aims to investigate the differences in hippocampal volume between wild and captive chimpanzees experiencing different sizes of home ranging areas and how these differences correlate with age. Approach: High-resolution 7T MRI scans were used to assess the hippocampal morphology of 16 chimpanzees (7 captive, 9 wild) and analyze their volumetric differences. Results: Wild chimpanzees exhibited significantly larger right hippocampal volumes compared to captives, while age correlated negatively with hippocampal volume across both groups. Impact: This research reveals that the ranging area size affects hippocampal structure linked to spatial memory in chimpanzees, contributing to our understanding of cognitive adaptations and the neural mechanisms underlying spatial navigation in primates.