ROLES OF CGMP-GATED CHANNELS IN RETINAL BIPOLAR NEURONS

CGMP 门控通道在视网膜双极神经元中的作用

• 批准号: 6702227
• 负责人: GARY G MATTHEWS
• 金额: $ 30.1万
• 依托单位: STATE UNIVERSITY NEW YORK STONY BROOK
• 依托单位国家: 美国
• 财政年份: 2001
• 资助国家: 美国
• 起止时间: 2001-02-01 至 2006-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6702227
• 关键词: alternatives to animals in research; cGMP dependent protein kinase; cyclic GMP; electrophysiology; flash photolysis; glutamate receptor; goldfish; image processing; immunocytochemistry; in situ hybridization; neural information processing; phosphodiesterases; polymerase chain reaction; retinal bipolar neuron; synapses; visual photoreceptor; visual phototransduction; voltage gated channel

DESCRIPTION (Applicant's Description): The goal of this project is to understand the molecular mechanisms of neurotransmitter responses in retinal bipolar neurons, with a focus on the roles of cyclic nucleotide-gated (CNG) channels. Visual signals from the photoreceptors are funneled to the rest of the brain exclusively through bipolar neurons, which therefore occupy a central position in retinal information processing. The separation of visual information into the ON pathway (in which cells depolarize in response to light) and the OFF pathway (in which cells hyperpolarize in response to light) occurs in bipolar neurons, at the first synapse in the visual system. The proposed research project will explore the cellular mechanisms that generate the ON pathway at the synapse between photoreceptor cells and ON bipolar neurons. At this synapse, glutamate released from the photoreceptor hyperpolarizes ON bipolar cells by activating a transduction cascade culminating in closure of cation channels. These cation channels may be members of the family of CNG channels, which open when cyclic GMP binds directly to the intracellular portion of the channel. A combination of electrical recording and fluorescence imaging techniques will be used to establish the role of CNG channels and cyclic GMP in the glutamate response of ON bipolar cells. Other potential roles of CNG channels will also be explored, such as modulation of neurotransmitter release in the synaptic terminal of the bipolar cell. Molecular biological techniques will be used to identify and characterize the CNG channel subtypes expressed in bipolar neurons. From amino acid sequences derived from complementary DNA encoding CNG channel subtypes, selective antibodies will be produced that can be used to localize the channel subtypes in isolated cells and retinal tissue. Biophysical characterization of CNG channel subtypes found in bipolar neurons will be carried out both in bipolar neurons and in cells transfected with full-length complementary DNA encoding a specific channel subtype. The proposed experiments will provide new information about the synaptic responses of an important class of retinal neurons and will specify physiological roles for specific types of CNG channels expressed in these neurons. Because cyclic nucleotide-gated channels are found in a variety of cell types throughout the nervous system, the results of the proposed project will also have general implications for cellular communication in the other parts of the brain.

描述（申请人的描述）：该项目的目标是 了解视网膜神经递质反应的分子机制 双极神经元，重点关注环核苷酸门控 (CNG) 的作用 渠道。来自光感受器的视觉信号被输送到其余部分 大脑完全通过双极神经元，因此占据了中枢 在视网膜信息处理中的地位。视觉上的分离 信息进入 ON 通路（其中细胞响应去极化 光）和 OFF 途径（其中细胞响应光而超极化） 发生在双极神经元中，位于视觉系统的第一个突触处。这 拟议的研究项目将探索产生的细胞机制 感光细胞和 ON 双极之间突触的 ON 通路 神经元。在这个突触处，谷氨酸从光感受器释放 通过激活转导级联使双极细胞超极化 最终导致阳离子通道关闭。这些阳离子通道可能是成员 CNG 通道家族的成员，当环 GMP 直接与 通道的细胞内部分。电子记录和 荧光成像技术将用于确定 CNG 的作用 ON 双极细胞谷氨酸反应中的通道和环 GMP。其他 还将探讨 CNG 通道的潜在作用，例如调节 双极细胞突触末端释放神经递质。 分子生物学技术将用于识别和表征 CNG 通道亚型在双极神经元中表达。从氨基酸序列 源自编码 CNG 通道亚型的互补 DNA，选择性 将产生可用于定位通道亚型的抗体 在分离的细胞和视网膜组织中。 CNG 的生物物理表征 双极神经元中发现的通道亚型将在双极神经元中进行 神经元和用编码a的全长互补DNA转染的细胞 特定通道子类型。拟议的实验将提供新信息 关于一类重要的视网膜神经元的突触反应和意志 指定特定类型 CNG 通道的生理作用 这些神经元。因为环核苷酸门控通道存在于多种 整个神经系统的细胞类型，所提议的结果 该项目还将对蜂窝通信产生普遍影响 大脑的其他部分。