Regulation by voltage and adenine nucleotides of a Ca - activated cation channel from hamster vomeronasal sensory neurons

structures, that lies beneath the rostral end of the nasal cavity, is thought to be the primary site for the detection of pheromones in mammals (Halpern, 1987; Wysocki & Meredith, 1987). Sensory transduction in the VNO is poorly understood, but is likely to be distinct from sensory transduction in the olfactory epithelium (Liman, 1996). In the olfactory epithelium, G protein-coupled receptors activate a Gs-like G protein (Golf), which leads to the activation of adenylyl cyclase, the generation of cAMP, and ultimately the opening of cyclic-nucleotide-gated (CNG) ion channels. Most of the components of transduction from the main olfactory epithelium are not expressed in the VNO, and VNO neurons do not respond electrically to intracellular injection of cAMP or cGMP (Dulac & Axel, 1995; Berghard et al. 1996; Liman and Corey, 1996; Wu et al. 1996).