PROPERTIES OF PEPTIDERGIC NEUROSECRETORY CELLS

脊椎动物中枢神经系统中的神经元接受和整合 来自众多传入突触输入的信息。 它们的动作电位 放电是它们的基本膜特性和 特定神经化学递质在任何给定时间的相互作用 这改变了膜的电导特性。 复杂的组织 脊椎动物中枢神经系统的体积小和大多数中枢神经元的体积小限制了其使用 许多当代电生理学和药理学技术 需要分析基本的膜特性和传递机制 体内作用。 我们已经开发了一个模型系统的研究， 突触整合控制的生物物理特性和机制 脊椎动物的肽能神经分泌细胞的活性， 鱼类的尾部神经分泌核。 两个电生理 方法已计划。 第一个将利用传统的细胞内 记录技术结合药物治疗， 表征基本膜特性并研究突触 特定传入输入刺激后的反应。 第二 方面将利用电压箝位技术来直接分析 电压依赖性和递质诱导的膜改变 电导 具体目标是： 1.建立基本的电生理学和药理学 尾神经分泌细胞的特征。 2.为了分析由特定的刺激产生的突触反应， 下降输入，并确定不同拮抗剂的影响 对突触电位的影响 3.为了表征体膜离子电导系统， 确定不同突触反应的离子基础， 电压钳技术。 4.分析假定的递质对生物物理的影响， 体膜的性质，并比较它们的反应与 刺激特定突触前神经元产生的生理反应 输入。 所获得的结果应提供有关一般情况的新信息。 神经分泌细胞的膜特性以及 调节这种神经元活动的突触整合。

Neurons in the vertebrate central nervous system receive and integrate information from numerous afferent synaptic inputs. Their action potential discharge is a function both of their basic membrane characteristics and the interaction at any given time of specific neurochemical transmitters which alter the membrane conductance properties. The complex organization of the vertebrate CNS and small size of most central neurons limits the use of many contemporary electrophysiological and pharmacological techniques needed to analyze basic membrane properties and mechanisms of transmitter action in vivo. We have developed a model system for the study of the biophysical properties and mechanisms of synaptic integration controlling the activity of defined vertebrate peptidergic neurosecretory cells in the caudal neurosecretory nucleus of fishes. Two electrophysiological approaches are planned. The first will utilize conventional intracellular recording techniques combined with pharmacological treatment to characterize basic membrane properties and to investigate the synaptic response following stimulation of specific afferent inputs. The second aspect will utilize voltage clamp techniques to analyze directly voltage-dependent and transmitter-induced alterations in membrane conductance. The specific aims will be: 1. To establish the basic electrophysiological and pharmacological characteristics of the caudal neurosecretory cells. 2. To analyze the synaptic response produced by stimulation of specific descending inputs and to determine the influence of different antagonists on the synaptic potentials. 3. To characterize the somal membrane ionic conductance systems, and determine the ionic basis of the different synaptic responses using voltage-clamp techiques. 4. To analyze the influence of putative transmitters on the biophysical properties of the somal membrane and compare their response with the physiological response produced by stimulation of specific presynaptic inputs. The results obtained should provide new information about the general membrane properties of neurosecretory cells as well as the mechanisms of synaptic intergration regulating the activity of this neuron type.