The Brain of the African Wild Dog. VI. The Motor System

Abstract

Social behaviors in the African wild dog involve a range of complex movements, including biting, pushing, embracing, mounting, face and muzzle licking, paw placement, play fighting, and wrestling. In this study, we employ a range of architectural and immunohistochemical stains to provide a qualitative description of the motor system in the brain of one representative individual of the African wild dog. The appearance of the motor system in the African wild dog does not differ substantively to that reported in other carnivores and is neurochemically like that of the domestic dog; however, one significant difference was detected: the presence of a distinct fascicle of protoplasmic commissural dendrites at the rostral pole of the hypoglossal nucleus. The chemoarchitecture and complement of motor cortical areas and dorsal thalamus, striatopallidal complex and associated nuclei, cerebellum, red nucleus, descending motor pathways, inferior olivary nuclear complex, cranial nerve motor nuclei, and ventral horn of the cervical spinal cord of the African wild dog do not reveal qualitative differences to that observed in the domestic dog. At the rostral pole of the hypoglossal nucleus, protoplasmic commissural dendrites form a distinct fascicle, this fascicle being a feature that has not been reported in other mammals. The presence of this feature indicates complex neural control of the tongue and may facilitate vocalization control through the potential combination of lateralized aspects of vocalizations in a nucleus playing a major role in the production of vocalizations.