tailieunhanh - Báo cáo sinh học : "Why do taste cells generate action potentials"

Tuyển tập các báo cáo nghiên cứu về sinh học được đăng trên tạp chí sinh học Journal of Biology đề tài: Why do taste cells generate action potentials? | Journal of Biology BloMed Central Minireview Why do taste cells generate action potentials Aurelie Vandenbeuch and Sue C Kinnamon Address Department of Otolaryngology and Rocky Mountain Taste and Smell Center 12700 E. 19th Ave Aurora CO 80045 USA. Correspondence Sue C Kinnamon. Email Published 28 April 2009 Journal of Biology 2009 8 42 doi jbiol138 The electronic version of this article is the complete one and can be found online at http content 8 4 42 2009 BioMed Central Ltd Abstract Taste cells regularly generate action potentials but their functional significance in taste signaling is unclear. A paper in BMC Neuroscience reveals the identity of the voltage-gated Na channels underlying action potentials providing the foundation for insights into their function. More than two decades ago Steve Roper first reported that the large taste cells of the aquatic salamander Necturus are electrically excitable and generate action potentials in response to membrane depolarization 1 . It is now well documented that the taste cells of most if not all vertebrate species regularly generate action potentials not only on electrical stimulation but also in response to apically applied chemical stimuli. But why should taste cells which are short receptor cells lacking axons require action potentials to activate gustatory afferent nerve fibers Graded receptor potentials are sufficient to evoke transmitter release from other short sensory receptor cells such as hair cells and photoreceptors. In fact taste cells appear to be the only non-neuronal sensory receptor cells to generate action potentials. Although the physiological significance of action potentials in taste transduction is still unclear a new report by Gao et al. in BMC Neuroscience 2 provides the molecular substrates to address this important question. They have identified three genes that encode the tetrodotoxin TTX -sensitive Na currents that underlie the action potential in .