Vomeronasal organ detects odorants in absence of signaling through main olfactory epithelium.

It is commonly assumed that odorants are detected by the main olfactory epithelium (MOE) and pheromones are sensed through the vomeronasal organ (VNO). The complete loss of MOE-mediated olfaction in type-3 adenylyl cyclase knockout mice (AC3-/-) allowed us to examine chemosensory functions of the VNO in the absence of signaling through the MOE. Here we report that AC3-/- mice are able to detect certain volatile odorants via the VNO. These same odorants elicited electro-olfactogram transients in the VNO and MOE of wild-type mice, but only VNO responses in AC3-/- mice. This indicates that some odorants are detected through an AC3-independent pathway in the VNO.