Mammalian pheromones

Abstract

Mammalian pheromones control a myriad of innate social behaviors and acutely regulate hormone levels. Responses to pheromones are highly robust, reproducible, and stereotyped and likely involve developmentally predetermined neural circuits. Here, I review several facets of pheromone transduction in mammals, including (a) chemosensory receptors and signaling components of the main olfactory epithelium and vomeronasal organ involved in pheromone detection; (b) pheromone-activated neural circuits subject to sex-specific and state-dependent modulation; and (c) the striking chemical diversity of mammalian pheromones, which range from small, volatile molecules and sulfated steroids to large families of proteins. Finally, I review (d) molecular mechanisms underlying various behavioral and endocrine responses, including modulation of puberty and estrous; control of reproduction, aggression, suckling, and parental behaviors; individual recognition; and distinguishing of own species from predators, competitors, and prey. Deconstruction of pheromone transduction mechanisms provides a critical foundation for understanding how odor response pathways generate instinctive behaviors.

Figure 1

(a) The anatomy of the mouse nose, including the main olfactory epithelium (MOE), vomeronasal organ (VNO), Grueneberg ganglion (GG), septal organ (SO), main olfactory bulb (MOB), and accessory olfactory bulb (AOB). (b) A cartoon depiction of a coronal section containing MOE (blue) and VNO (red) neuroepithelium. (c) Taar2 cRNA riboprobes label MOE but not VNO sensory neurons by in situ hybridization, with pseudocoloring to facilitate visualization (author’s own data). (d ) Expression patterns of genes indicated in VNO sections determined by using in situ hybridization. Adapted from References and with permission.