Continuing Studies on the Evolution of Ion Channels

本研究项目将调查离子通道在 水母和扁形虫的神经元。 虽然神经元在 水母的功能与高等神经元的功能非常相似 动物，他们至少有一个属性，可以反映他们的 作为最原始的动物， 有神经系统的 它们的钠生理学- 依赖性动作电位基本上与 其他动物的钠电流，但这些动物的药理学 电流就是钙电流。 生化和 电生理技术将被用来阐明 水母神经元快钠通道的结构。 安德森博士还将研究的多样性和性质， 扁形虫的离子通道 扁形虫是“第一种”动物 拥有一个集中的大脑，因此占据一个 在神经系统进化中的重要地位。 这些动物 是最不敏感的生物体 河豚毒素钠通道阻滞剂 此外这些 动物是寄生虫的主要种类， 他们的兴奋细胞的生理学可能导致发展 新的驱虫药种类。 本研究将提供 关于神经系统如何进化的重要事实 的 生理学和药理学的离子通道在最原始的 拥有神经系统的动物将允许与 在原始和更先进的动物中。 结果 从这项研究中获得的信息将提供有用的信息， 通过识别离子通道的亚型 在高等动物中也有类似的情况。

This research project will investigate ion channels in the neurons of the jellyfish and the flatworm. Although neurons in the jellyfish function in much the same way as neurons in higher animals, they have at least one property that may reflect their evolutionary position of being the most primitive animal possessing a nervous system. The physiology of their sodium- dependent action potentials is essentially the same as that of sodium currents of other animals but the pharmacology of those currents is that of calcium currents. Biochemical and electrophysiological techniques will be employed to elucidate the structure of the fast sodium channel in neurons of the jellyfish. Dr. Anderson will also examine the diversity and properties of ion channels in the flatworm. Flatworms are the "first" animals to possess a centralized brain, therefore occupying an significant position in nervous system evolution. These animals are the lowest organism reported of being sensitive to tetrodotoxin, a sodium channel blocker. Furthermore these animals are a major class of parasites and information about the physiology of their excitable cells may lead to the development of new classes of anthelminthic drugs. This study will provide important facts about how nervous systems evolved. The physiology and pharmacology of ion channels in the most primitive animals possessing a nervous system will allow comparisons with channels in primitive and more advanced animals. Results obtained from this study will provide useful information to neurobiology in general by identifying subtypes of ion channels with equivalents in higher animals.