From odor and pheromone transduction to the organization of the sense of smell.

Chemosensory neurons in the mammalian nose detect an array of odors and pheromones that carry essential information about the animal's environment. How the nose organizes this immense amount of information is a major question in sensory biology. New evidence suggests that there are several subpopulations of sensory neurons in the nose that project to different areas in the forebrain. Strikingly, evidence is now emerging that several of these neuronal subpopulations employ distinct second messenger cascades to transduce chemical stimuli. This new understanding of the heterogeneity of chemosensory transduction mechanisms offers the opportunity to use genetically altered animals to specifically target these subpopulations. Such approaches should enable researchers to examine the role that each of these subsystems could play in chemosensory-dependent behaviors.