Vomeronasal sensory input and its social behavioral output

Many animals utilize pheromones as chemical substances that regulate reproductive and social behaviors. Elucidating how diverse pheromonal compounds are detected and translated into specific behavioral and physiological responses is crucial for understanding animal behavior. In vertebrates, pheromone reception is primarily mediated by the vomeronasal organ. Vomeronasal sensory neurons detect a broad range of semiochemical molecules, including pheromones and allelochemicals, and transmit this information via the accessory olfactory bulb to higher brain regions, such as the amygdala and hypothalamic regions. Although recent studies have advanced the identification of pheromonal molecules and the analysis of the neural circuits responsible for their detection, ligands have been identified for only a small fraction of the hundreds of vomeronasal receptors. Analyses of genetically engineered mice lacking key components of vomeronasal signal transduction in vomeronasal sensory neurons have provided comprehensive insights into the relationship between vomeronasal sensory input and behavioral output. This review focuses on pheromones among the semiochemicals detected by the vomeronasal organ and summarizes current understanding of pheromonal perception and associated social behaviors, primarily based on studies in mice, the most extensively investigated model organism to date.