CHOLINOCEPTIVE NEURONS IN THE RETINA

乙酰胆碱（ACh）是脊椎动物视网膜中的一种递质， 许多神经节细胞的反应特性八个阿尔法和三个贝塔 神经元烟碱乙酰胆碱受体（nAChR）的亚基已经被 克隆出来的，并且已经产生了抗体。这些亚单位可以 联合收割机形成大量的nAChR亚型，每种亚型的特征是 独特的亚基组成以及生理和药理学特征。 具体目标是基于以下假设：1）不同的视网膜 细胞类型表达nAChR亚型的不同组合，2） 不同的nAChR亚型在视网膜中起不同的功能作用。 1.抗血清生产：针对合成的 对应于鸡和哺乳动物α的独特序列的肽 和β亚基的研究将继续进行。这些将用于 具体目标2、3和5中描述的研究。 2.在禽类和哺乳动物中表达nAChR的细胞的表征 哺乳动物视网膜：抗α和β亚单位的抗体和抗血清 将用于确定鸡，大鼠， 和兔子视网膜nAChr表达细胞将根据以下条件进行鉴定： 它们的神经递质、酶或其他分子标记物的含量， 通过传统的双标记研究发现。的空间关系 在表达nAChR的细胞的树突和 其他神经元也将以同样的方式进行研究。 3.视网膜nAChR亚基组成和丰度的测定 亚型：使用相同抗体的免疫沉淀实验， 如上所述的抗血清将用于确定 鸡和兔视网膜nAChR，并量化其相对丰度。 4.胆碱能无长突细胞亚群的特征： 兔视网膜的胆碱能无长突细胞包含至少两个 基于nAChR和GABA表达的亚群。这些亚群 将根据其密度、分布和 这些细胞的树突与 其他视网膜神经元 5.发育中哺乳动物视网膜的胆碱能回路：亚单位 特异性抗体和抗血清将与 市售抗血清以确定胆碱的模式 出生后视网膜中乙酰转移酶、GABA和nAChR的表达 已知年龄的雪貂

Acetylcholine (ACh) is a transmitter in the vertebrate retina that affects the response properties of many ganglion cells. Eight alpha and three beta subunits of neuronal nicotinic acetylcholine receptors (nAChRs) have been cloned, and antibodies have been raised against them. These subunits can combine to form a large number of nAChR subtypes, each characterized by a unique subunit composition and physiological and pharmacological profile. The specific aims are based on the hypothesis that 1) different retinal cell types express different combinations of nAChR subtypes, and that 2) different nAChR subtypes serve different functional roles in the retina. 1. Antisera production: The production of antisera against synthetic peptides corresponding to unique sequences of chick and mammalian alpha and beta subunits will be continued. These will then be used for use in the studies described in Specific Aims 2, 3, and 5. 2. Characterization of the nAChR-expressing cells in the avian and mammalian retina: Antibodies and antisera against alpha and beta subunits will be used to determine the nAChR expression pattern in the chick, rat, and rabbit retina. nAChr-expressing cells will be identified based upon their content of neurotransmitters, enzymes, or other molecular markers as revealed by conventional double label studies. The spatial relationships between the dendrites of the nAChR-expressing cells and the processes of other neurons will be studied in the same fashion. 3. Determination of the subunit composition and abundance of retinal nAChR subtypes: Immune precipitation experiments using the same antibodies and antisera as above will be used to determine the subunit composition of chick and rabbit retinal nAChR and to quantify their relative abundance. 4. Characterization of subpopulations of cholinergic amacrine cells: The cholinergic amacrine cells of the rabbit retina comprise at least two subpopulations based upon nAChR and GABA expression. These subpopulations will be characterized in terms of their density, distribution, and the spatial relationships between the dendrites of these cells and those of other retinal neurons. 5. Cholinergic circuitry in the developing mammalian retina: Subunit specific antibodies and antisera will be used in conjunction with commercially available antisera to determine the pattern of choline acetyltransferase, GABA, and nAChR expression in retinas from postnatal ferrets of known ages.