NEURONAL NICOTINIC ACETYLCHOLINE RECEPTORS

这项研究的长期目标是描述神经元的特征。 烟碱型乙酰胆碱受体(NAChRs)抗原性 结构、在神经元表面的分布及对神经细胞的调控 它们在发育过程中的表达。视顶盖内的神经元nAChRs 在青蛙的自主神经节中，将使用交叉反应进行研究 抗电提纯nAChRs的单抗 器官和骨骼肌，由乔恩·林德斯特罗姆博士提供。在……里面 初步结果已发现其中一些单抗与该蛋白结合 林蛙顶盖的一部分，接受一个主要的突起 从视网膜上。与以前的工作相比，这些结果很有趣 表明甲型银环蛇毒素和其他烟碱拮抗剂出现 以阻断几种低等脊椎动物的视网膜顶盖传输。 第一个具体目标将是进一步表征分子(S)在 被抗受体单抗识别的顶盖。如果这些单抗真的 识别支持视网膜顶盖突触传递的受体，他们 应与紧靠神经节下方的顶盖神经元表面结合 手机终端。这一预测将在精细结构 使用免疫过氧化物酶和免疫金技术，同时 标记顶盖的神经节细胞传入。的约束性 α-银环蛇毒素也将使用HRP标记的 α-银环蛇毒素，以及毒素结合的位置将与 单抗结合部位。 第二个具体目标将是使用交叉反应的多克隆和 用于鉴定自主神经表面nAChRs的单抗 神经节细胞。与突触后膜结合的抗体将是 假定与神经节细胞表面的nAChRs发生交叉反应。这个 神经节nAChRs的分布将使用免疫金进行测量 或电子显微镜放射自显影技术来测量 哪些神经元的nAChRs集中在突触下膜。这个 突触前神经对nAChR分布的影响 通过对神经节前病变前后抗体结合的研究确定 神经丧失。 这些研究将有助于提高我们对结构和 神经元性乙酰胆碱受体的调节。

The long-term objective of this research is to characterize neuronal nicotinic acetylcholine receptors (nAChRs) as regards to their antigenic structure, their distribution on the neuronal surface and the control of their expression during development. Neuronal nAChRs in the optic tectum and in autonomic ganglia of the frog will be studied using cross-reacting monoclonal antibodies (mAbs) made against purified nAChRs from electric organ and skeletal muscle and provided by Dr. Jon Lindstrom. In preliminary results a number of these mAbs have been found to bind to that part of the optic tectum of Rana pipiens which receives a major projection from the retina. These results are interesting in light of previous work indicating that Alpha-bungarotoxin and other nicotinic antagonists appear to block retinotectal transmission in several lower vertebrate species. The first specific aim will be to further characterize the molecule(s) in the tectum that are recognized by anti-receptor mAbs. If these mAbs indeed recognize receptors which subserve retinotectal synaptic transmission, they should bind to the surface of tectal neurons immediately beneath ganglion cell terminals. This prediction will be tested at the fine structural level using immunoperoxidase and immunogold techniques while simultaneously labeling ganglion cell afferents to the tectum. The binding of Alpha-bungarotoxin will also be visualized using HRP-labeled Alpha-bungarotoxin, and the sites to which toxin binds will be compared to mAb binding sites. The second specific aim will be to use cross-reacting polyclonal and monoclonal antibodies to characterize nAChRs on the surface of autonomic ganglion cells. Antibodies which bind to the postsynaptic membrane will be assumed to cross-react with nAChRs on the ganglion cell surface. The distribution of ganglionic nAChRs will be measured using immunogold techniques or electron microscopic autoradiography to measure the extent to which neuronal nAChRs are concentrated in the subsynaptic membrane. The influence of the presynaptic nerve upon nAChR distribution will be determined by studying antibody binding before and after preganglionc denervation. These studies will serve to improve our understanding of the structure and regulation of neuronal acetylcholine receptors.