Sensory Adaptations: Insights into the Vomeronasal System of the Iberian Wolf

ABSTRACT Wolves, like other canids, extensively use chemical signals for various aspects of communication, including territory maintenance, reproductive synchronization, and social hierarchy signaling. Pheromone-mediated chemical communication operates unconsciously among individuals, acting as a mysterious sixth sense that regulates both their physiology and behavior. Despite their crucial role in the life of the wolf, there is a surprising lack of comprehensive research on the neuroanatomical and physiological bases of chemical communication in wolves. This study delves into the Iberian wolf vomeronasal system (VNS) and examines potential changes brought about by dog domestication. Our findings show that the Iberian wolf possesses a fully functional VNS vital for pheromone-mediated communication. While macroscopic similarities between the wolf and domestic dog VNS are observed, there are notable microscopic differences. These include the presence of neuronal clusters associated with the sensory epithelium of the vomeronasal organ (VNO) and a higher differentiation degree of the accessory olfactory bulb (AOB). Immunohistochemical markers reveal the expression of the two main families of vomeronasal receptors (V1R and V2R) in the VNO. However, only the V1R family is expressed in the AOB. These findings not only provide deep insights into the VNS of the wolf but also hint at how domestication might have altered neural configurations that underpin species-specific behaviors. This understanding has implications for innovative strategies, such as employing semiochemicals for wolf population management, aligning with modern conservation goals.