Chemosensory Ion Channels in Amphibian Skins

两栖动物在脊椎动物中是独一无二的，它们通过皮肤而不是口腔吸收盐和水。 为了做到这一点，蟾蜍采取了一种被称为吸水反应的特征行为，将腹部压在潮湿的表面上。 一些蟾蜍在沙漠环境中生存的能力要求它们正确识别有水的表面，而不是不适当地充满盐。 蟾蜍的皮肤似乎起到了类似于舌头在吞咽之前品尝溶液的功能。 这个项目测试了一个新的假设，即蟾蜍皮肤品尝钠盐的细胞过程与舌头中的味蕾细胞相似。 本研究以沙漠蟾蜍为研究对象，从行为学、细胞学和神经生理学三个层面来探讨盐味的传导过程。 研究结果将阐明动物体表的细胞如何将环境中水的含盐量传达给神经系统，从而决定如何利用这些水。 这项工作将对神经科学之外的一般生理学产生影响，阐明感知与行为相结合，以维持水盐平衡。 结果也将是重要的环境生物学，在澄清两栖动物如何容忍极端的水的可用性和水质，以及如何环境退化可能会影响两栖动物种群的生存。

Amphibians are unique among the vertebrates in obtaining salt and water by absorption across the skin rather than by mouth. To do this, toads adopt a characteristic behavior, called the water-absorption response, pressing the belly to a moist surface. The ability of some toads to survive in desert environments requires them to correctly identify surfaces where water is available, and not filled inappropriately with salts. The toad skin appears to serve an analogous function to the way the tongue tastes solutions before swallowing. This project tests the novel hypothesis that the cellular process of tasting sodium salts by the toad skin is similar to that for taste bud cells in the tongue. This project uses desert toads to evaluate the process of salt taste transduction at the behavioral, cellular, and neurophysiological levels in this unique model system. Results will clarify how cells at the surface of an animal can communicate the salt content of water in the environment to the nervous system, to allow a decision of how to utilize that water. This work will have an impact beyond neuroscience on general physiology, in clarifying perception is coupled to behavior to maintain water and salt balance. Results will also be important for environmental biology, in clarifying how amphibians tolerate extremes in water availability and water quality, and how environmental degradation may affect survival of amphibian populations.