The role of main olfactory and vomeronasal systems in animal behaviour and reproduction

In many terrestrial tetrapod, olfactory sensory communication is mediated by two anatomically and functionally distinct sensory systems; the main olfactory system and vomeronasal system (accessory olfactory system). Recent anatomical studies of the central pathways of the olfactory and vomeronasal systems showed that these two systems converge on neurons in the telencephalon providing an evidence for functional interaction. The combined anatomical, molecular, physiological and behavioural studies have provided new insights into the involvement of these systems in pheromonal perception and their influence on the neuroendocrine pathways. The olfactory and vomeronasal systems have overlapping functions and both are involved in responses to both pheromones and chemical odorants. Several studies in insects, amphibians rodents and ungulates have established the importance of pheromones in the astonishing influence exerted by the male on the reproductive activity of the female. The great diversity of signals used in chemical communication indicates that this communication is not mediated exclusively by pheromones. A number of pheromonal responses are not dependent on the vomeronasal system, but on the main olfactory system. The dual olfactory systems also have overlappng functons. The importance of this organ in reproductve and socia behaviours was the aim of carrying out the review on its basic morphology and functional correlations in order to encourage more future studies of this important organ of our local species and breeds of mammals.Keywords: Main olfactory system, Vomeronasal system, Pheromones, Behaviour, Mammal