NEURONAL ACETYLCHOLINE RECEPTOR MECHANISMS

神经系统中的交流是通过信号的传递来进行的 神经突触 突触的功能和调节的规则， 神经递质受体将是重要的，在了解更高的大脑 功能协调发展的 神经元烟碱乙酰胆碱受体（AChRs）介导 突触传递在整个神经系统，但仍然很差 表征了 鸡睫状神经节神经元提供了一个有用的系统， 研究神经元乙酰胆碱受体 神经元表现出小的和大的电导 AChR亚型在整个发展过程中，和最近的cDNA克隆策略 发现了编码α和β AChR亚单位的基因， 神经节 上一笔赠款资助的研究集中在 AChRs在神经元上的功能、发育和调节。 本 更新将建立在这些早期研究的基础上。 实验利用 非洲爪蟾卵母细胞表达系统将研究的分子基础 神经节中潜在的AChR亚型。 表达 研究将集中在比较天然睫状体中的AChR特性， 神经节神经元，与乙酰胆碱受体表达在青蛙卵母细胞后， 注射编码AChR亚基的神经节mRNA。 第二主 方向将是探索控制调节的机制， 发育过程中睫状神经节神经元上的AChRs和突触， 对环腺苷酸第二信使系统激活的反应。 的 神经元实验将为受体和 突触可以通过细胞-细胞相互作用来修饰。

Communication in the nervous system takes place by transmission of signals at synapses. Rules governing the function and regulation of synapses and neurotransmitter receptors will be important in understanding higher brain functions. Neuronal nicotinic acetylcholine receptors (AChRs) mediate synaptic transmission throughout the nervous system, but remain poorly characterized. Chick ciliary ganglion neurons provide a useful system for studying neuronal AChRs. The neurons display small and large conductance AChR subtypes throughout development, and recent cDNA cloning strategies have uncovered genes encoding alpha and beta AChR subunits in the ganglion. Studies funded by the previous grant concentrated on the function, development and regulation of AChRs on the neurons. The present renewal will build on those earlier studies. Experiments utilizing the Xenopus oocyte expression system will examine the molecular basis underlying functional AChR subtypes in the ganglion. The expression studies will focus on comparing AChR properties seen in the native ciliary ganglion neurons, with AChRs expressed in frog oocytes following the injection of ganglionic mRNAs coding for AChR subunits. A second major direction will be to explore the mechanisms controlling the regulation of AChRs and synapses on ciliary ganglion neurons during development, and in response to activation of a cyclic AMP second messenger system. The neuronal experiments will provide new insights into the ways receptors and synapses can be modified by cell-cell interactions.