Neuroanatomy of the olfactory bulb of the coyote (Canis latrans): Connection to social information processing

Olfactory cues help animals find food, detect predators, and communicate social information. In vertebrates, the olfactory bulb is the primary processing site for olfactory cues. We used a combination of histological stains and immunohistochemistry experiments to characterize the structure and organization of the main olfactory bulb (MOB) in a generalist canid, the coyote ( Canis latrans ). We also used receptor autoradiography to localize the receptors for neuropeptides oxytocin (OXT) and vasopressin (AVP), which are two hormones that are implicated in social behavior. While coyotes have been studied extensively with respect to wildlife biology and ecology, there has been limited research into olfactory signaling in the coyote, and no previous work has examined the coyote olfactory system. Like most mammals, the coyote MOB has a laminar structure with a defined glomerular layer. Mean glomerular diameter across three individuals is 204.0 ± 20.9 µm. Localization of OXT receptors to the glomerular layer in the MOB is consistent with OXT’s known roles in social learning and behavior through the modulation of olfactory signals. Structural and chemical features of the coyote MOB are considered in a comparative context, providing a foundation for understanding how olfactory neurobiology may relate to a species’ social and ecological environments.