Vomeronasal transduction

FIGURE 50-6 A model for chemosensory transduction in vomeronasal sensory neurons. The individual steps are detailed in the text. In contrast to the transduction cascade in OSNs, the mechanism of vomeronasal transduction is less well characterized. Vomeronasal neurons express either V1R or V2R receptors and either Got. or Ga0, respectively. The TRPC2 channel subunit is expressed in all vomeronasal neurons, and may be part of a multimeric channel complex. Ca2+ions are represented as purple balls, Na+ ions as blue balls. VR, vomeronasal receptor (VlRorV2R) PIP2, phospha-tidylinositol 4,5-bishphosphate IP, inositol 1,4,5-trisphosphate DAG, diacylglycerol. 

Berghard A. and Buck L.B. (1996). Sensory transduction in vomeronasal neurons evidence for G-alpha-o, G-alpha-i2, and adenylyl cyclase II as major components of a pheromone signaling cascade. J Neurosci 16, 909-918. 

Liu J., Chen P., Wang D. and Halpem M. (1999). Signal transduction in the vomeronasal organ of garter snakes ligand-receptor binding mediated protein phosphorylation. Biochem Biophys Acta 1450, 320-330. 

Wu Y., Tirindelli R, and Ryba N.J. (1996). Evidence for different chemo-sensory transduction pathways signal in olfactory and vomeronasal neurons. Biochem Biophys Res Comm 220, 900-904. 

Chemosensory neurons of the vomeronasal system are narrowly tuned to specific chemical cues, and utilize a unique mechanism of sensory transduction 824... 

Lucas, P. et al. A diacylglycerol-gated cation channel in vomeronasal neuron dendrites is impaired in TRPC2 mutant mice mechanism of pheromone transduction. Neuron 40 551-561, 2003. 

Second messenger cascades in vomeronasal sensory cells Although the functional implications of the PLC/IP3 cascade in olfactory neurons of nasal epithelium remains mysterious, there is mounting evidence that phospholipase C is a key enzyme for signal transduction in chemosensory neurons... 

Kimoto H, Haga S, Sato K, Touhara K (2005) Sex-specific peptides from exocrine glands stimulate mouse vomeronasal sensory neurons. Nature 437 898-901 Kinnamon SC, Margolskee RF (1996) Mechanisms of taste transduction. Curr Opin Neurobiol 6 506-513... 

Spehr M, Hatt H, Wetzel CH (2002) Arachidonic acid plays a role in rat vomeronasal signal transduction. J Neurosci 22 8429-8437... 

PREY CHEMICAL SIGNAL TRANSDUCTION IN THE VOMERONASAL SYSTEM OF GARTER... 

Jiang, X. C., Inouchi, J., Wang, D., and Halpem, M., 1990, Purification and characterization of a chemoattractant from earthworm electric shock-induced secretion, its receptor binding, and signal transduction through the vomeronasal system of garter snakes, J. Biol. Chem. 265 8736-8744. 

Wang, D. Chen, P., Li, C.-S., and Halpern, M., 1988, Chemosignal transduction in the vomeronasal organ of garter snakes Ca -dependent regulation of adenylate cyclase. Arch. Biochem. Biophys. 267 459-466. 

Our previous research showed that there is a relationship, albeit complex, between behavioral sensitivity to androstenone and membrane-bound alkaline phosphatase activity in olfactory and vomeronasal epithelia (Chukhrai et al., 1997a, b). Hence, we used biochemical measures of alkaline phosphatase activity to establish the duration of correlated changes in the receptor epithelium that were induced by exposures to androstenone. These measures of alkaline phosphatase activity, a protein that is membrane-bound and thought to be involved in transduction processes, are indirect measures of in situ changes in reactivity of the sensory epithelium. By itself, a change in alkaline phosphatase activity cannot fully account for shifts in sensitivity to androstenone however, it does provide a measure of correlated effects. 

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