Visualisation of the vomeronasal pheromone response system.

Mammalian vomeronasal receptors respond to pheromones conveying information on gender, reproductive status and individual recognition. The question arises as to how this information is coded, which parts of the code require combinatorial activity and whether or not there are specific receptor neurons committed to sex discrimination. Are there receptor neurons that are committed to responding for female or male pheromones? Is there a sex difference for the proportion of these receptors, bearing in mind that it is very much in the male's interest to distinguish the restricted oestrous phase of the female's cycle in order to successfully mate? Perhaps more intriguing is the complexity of individual recognition and whether or not the vomeronasal receptors actually possess this capacity. A recent paper in Science by Ron Yu and colleagues addresses these issues by literally visualising patterns of activity in VNO slices and determining what information is common across different individuals and what distinguishes them.