The Brain of the African Wild Dog. V. The Somatosensory System and Vestibular Nuclear Complex.

Social behaviors in the African wild dog (Lycaon pictus) commonly involve a range of tactile aspects, including biting, pushing, embracing, mounting, face and muzzle licking, nose-chin and muzzle contact, paw placement, play fighting, and wrestling, supported by the vestibular system. We employed an array of architectural and immunohistochemical stains to provide a qualitative description of the somatosensory and vestibular systems in the brain of one representative African wild dog individual. The appearance of both systems does not appear to differ from that reported in other Carnivora. The six nuclei forming the vestibular system, and their relationship to each other and the incoming vestibular branch of the eighth cranial nerve, appear like those observed in many mammalian species. The location and appearance of the dorsal column nuclei, the trigeminal sensory column, the colliculi, somatosensory nuclei of the dorsal thalamus, and the five somatosensory cortical areas observed in the African wild dog are like those observed in the domestic dog and other Carnivora. This study of the somatosensory and vestibular systems of the African wild dog completes our series of studies describing the major sensory systems in the African wild dog brain. It appears reasonable to conclude that, at the systems level of analysis, no overt specializations of any of the sensory systems are present. Thus, the neural underpinnings of the complex sociality of the African wild dog may be supported by nonsensory neural systems, such as motor, neuromodulatory, limbic, or cognitive systems, or levels of organization like receptor expression patterns or connectivity.