Cerebellar encephalic vascularization of Alouatta belzebul: contributions to the comparative morphology of primates

We studied cerebellar vascularization in five specimens of the primate Alouatta belzebul, with the objective of describing the anatomy of the cerebellar arteries, their possible variations and comparing them with the pattern of other primates. The arterial system was injected with stained latex (Neoprene 650) through the thoracic aorta and fixed in a 10 % aqueous solution of formaldehyde. After dissection, we observed that the cerebellum of this primate species is irrigated exclusively by the vertebrobasilar system, formed by the vertebral and basilar arteries, which emit four main pairs of cerebellar arteries: caudal inferior cerebellar, rostral inferior cerebellar, anterior cerebellar, and superior cerebellar. These arteries originated from the vertebral and basilar arteries, and followed different paths to supply all portions of the cerebellum, meeting at intersecting and causing anastomoses between the different branches. The results obtained demonstrated similarities between the vascularization of A. belzebul and other human and non-human primates and reinforced the importance of this comparative analysis of brain vascularization between primates, as it contributes to the understanding of morphological variations and has applications in clinical, evolutionary, and conservationist studies.

Keywords:
cerebellar arteries; comparative morphology; neotropical primates; vertebrobasilar system.