MODULATION AND REGULATION OF NEURONAL CALCIUM CHANNELS

电压门控钙通道在钙离子通道中起关键作用 所有可兴奋细胞中细胞功能的调节。第一，钙离子 通过通道进入对转导 电信号转化为特定的细胞反应，包括 神经递质释放和激素分泌，调节 通过钙激活离子通道的兴奋性，收缩， 基因转录的调控等。第二，因为它们的 与电压相关的属性，通道是重要元素 最近的电生理学和药理学实验 证明了电压门控钙通道构成了 背根神经节(DRG)中的通道已被描述 细胞，并被命名为L、N和T型。渠道类型 它们的时间和电压特性不同，并且 药理特性。他们还可能对 不同的功能反应。 神经科学中的一个基本问题是关于 递质和神经调节剂释放的调节。的作用 分泌过程中不同类型的钙通道将 L)利用膜片钳记录技术表征 神经制剂中存在的钙通道类型 终末和内分泌细胞系； 2)研究钙离子通道活性的调节。 递质/神经调节剂及其相关的第二信使 这些制剂中的系统； 3)用放射免疫分析技术监测激素释放 同时操纵钙通道的活动。 神经系统中的所有信号都由电 在神经元上转化为化学信息的脉冲 突触。由于通道是这种电信号传递的基础 对于化学信号来说，有关其性质的信息至关重要 了解正常和异常神经系统的各个方面 功能。

Voltage-gated calcium channels play a critical role in the regulation of cellular function in all excitable cell. First, CA2+ entry through the channel is crucial to the tranduction of electrical signals into specific cellular responses including neurotransmitter release and hormone secretion, regulation of excitability via Ca-activated ionic channels, contraction, regulation of gene transcription, etc. Second, because of their voltage-dependent properties, the channels are important elements contributing to the excitable properties of cells. Recent electrophysiological and pharmacological experiments have demonstrated that voltage-gated calcium channels constitute a family of diverse, but related, proteins. Three types of calcium channels have been characterized in dorsal root ganglion (DRG) cells and have been termed L-, N-, and T-types. The channel types vary in their time-and voltage-dependent properties, and pharmacological properties. They may also be responsible for different functional responses. One of the fundamental questions in neuroscience concerns the regulation of transmitter and neuromodulator release. The role of the different types of calcium channels in secretory processes will be assessed in this proposal by: l) utilizing patch clamp recording techniques to characterize the types of calcium channels present in a preparation of nerve terminals and in an endocrine cell line; 2) studying the modulation of calcium channel activity by transmitters/neuromodulators and their associated second messenger systems in these preparations; 3) monitoring hormone release with radioimmunoassay techniques while manipulating calcium channel activity. All signalling in the nervous system consists of electrical impulses which are translated into chemical messages at neuronal synapses. Since channels underlie this transduction of electrical to chemical signals, information about their properties is critical to understanding all aspects of normal and abnormal nervous system function.