Cellular Mechanisms of Hypoxic Chemotransduction in Avian Carotid Bodies

IBN-9723783 PI：Hempleman在通向陆生脊椎动物头部的血管壁中的专门化化学感受细胞形成称为颈动脉体的受体器官。 当血液中的氧含量太低时，这些神经细胞会做出反应，这种情况称为缺氧。 具有高代谢率的鸟类和哺乳动物依赖于成功的反射来维持高血氧，当适应低氧可用性的高海拔时，这些反射特别需要。 在哺乳动物中，已知细胞对缺氧的反应依赖于钾离子的膜通道。 我们对鸟类知之甚少，尽管有些高空飞行的鸟类在大多数脊椎动物无意识的高度活动。 本计画利用细胞电生理技术及钙敏感染料来探讨鸟类血液氧的化学传导机制。 结果将提供非哺乳动物颈动脉体的氧转导机制的第一个分析，并将有超越感官系统的进化和比较生理学的影响，并了解环境适应。

IBN-9723783 PI: Hempleman Specialized chemosensory cells in the walls of blood vessels leading to the head of terrestrial vertebrates form receptor organs called the carotid bodies. These nerve cells respond when the oxygen content of the blood is too low, the condition called hypoxia. Birds and mammals with high metabolic rates depend on successful reflexes to maintain high blood oxygenation, and these reflexes are particularly needed when adapting to high altitudes with low oxygen availability. In mammals it is known that the cellular responses to hypoxia depend on a membrane channel for potassium ions. In birds we know very little, although some high-flying birds function at altitudes where most vertebrates would be unconscious. This project uses cellular electrophysiological techniques and calcium-sensitive dyes to investigate the chemotransduction mechanisms for blood oxygen in birds. Results will provide the first analysis of oxygen transduction mechanisms in non-mammalian carotid bodies, and will have an impact beyond sensory systems to evolutionary and comparative physiology, and to understanding environmental adaptations.