Histological examination of neuroanatomical and ocular structures in the Gambian Sun squirrel (Heliosciurus gambianus Ogilby, 1835) for understanding arboreal adaptations.

Abstract

Arboreal environments require specialized adaptations in sensory and neuroendocrine systems for species survival. This study examines the neuroanatomical and histological adaptations of the Gambian Sun squirrel (Heliosciurus gambianus), focusing on structures critical for visual processing, sensorimotor integration, and neuroendocrine regulation in arboreal habitats. Paraffin-embedded eye and brain samples from three male Gambian Sun squirrels captured at the University of Ibadan, Nigeria, were analyzed using standard hematoxylin and eosin and Masson trichrome staining techniques. The cornea displayed a unique undulating cellular arrangement, which may likely enhance visual acuity and protection in densely forested environments. Neuroanatomical examination revealed distinctive features in the median eminence, pineal gland, subcommissural organ, dorsal lateral geniculate nucleus, rostral colliculus, and optic nerve, which support sensorimotor coordination and neuroendocrine functions. These specialized traits enable environmental navigation and survival, emphasizing their role in arboreal adaptation. The findings provide a foundation for comparative studies with other rodents and contribute to understanding evolutionary strategies in tree-dwelling mammals. Additionally, this research offers potential applications in conservation efforts and neurobiological studies, including insights into human neurological functions.