CENTRAL NICOTINIC CHANNEL KINETICS AND SYNAPTIC FUNCTION

本提案的目的是研究以下因素之间的相互作用： 神经递质乙酰胆碱（ACh）和中枢烟碱 胆碱能受体（nAChR）通道，以了解功能 烟碱突触传递在中枢神经系统（CNS）。 尽管有强有力的神经化学证据表明某些胆碱能通路 投射到富含nAChRS的大脑区域，关于nAChRS的信息很少。 nAChR参与突触传递的研究已经通过使用 常规生理技术。在无法 直接检查中央烟碱突触，一种不同的策略将是 必需的.本提案的总体实验设计基于 一般原则，发射机，如乙酰胆碱，迅速释放， 从突触间隙中清除使用快速灌注技术， ACh将应用于小细胞和外向贴片中的nAChR。 因此，乙酰胆碱会迅速激活nAChRs， 类似于突触刺激。这种方法将提供一个强大的 研究nAChR通道行为的方法， 真实的突触反应的性质。这些实验将特别 包括评估ACh与nAChRs的快速结合， 和开放nAChR通道，烟碱突触的持续时间 反应和nAChR返回到其静息状态。此外 在这些研究中，中枢胆碱能神经元的原代培养将是 因此，在突触前和突触后位点的nAChR的激活可以 直接检查。 突触传递是神经元 一个神经元的输出很大程度上由 整合它接收到的各种传入突触信号。的 突触反应的特定特征，由相互作用决定 感受器和传递器之间的相互作用，将控制信号的影响， 会对神经元的整体特性产生影响。因此， nAChRs的突触激活的基本特征， ACh对于理解正常的 胆碱能系统在突触传递和可塑性， 胆碱能神经元丢失在某些退行性疾病中的全部意义 疾病

The objectives of this proposal are to investigate the interaction between the neurotransmitter, acetylcholine (ACh), and central nicotinic cholinergic receptor (nAChR) channels, in order to understand the function of nicotinic synaptic transmission in the central nervous system (CNS). Despite strong neurochemical evidence that certain cholinergic pathways project to brain regions rich in nAChRS, little information regarding the participation of nAChRs in synaptic transmission has been obtained using conventional physiological techniques. In the absence of being able to examine central nicotinic synapses directly, a different strategy will be required. The overall experimental design of this proposal is based on the general principal that transmitters, such as ACh, are rapidly released and cleared from the synaptic cleft. Using rapid perfusion techniques, pulses of ACh will be applied to nAChRs in small cells and outside-out patches. Thus, nAChRs will be rapidly activated by ACh in a manner that is analogous to synaptic stimulation. This approach will provide a powerful means of studying the behavior of nAChR channels with respect to the properties of a real synaptic response. The experiments will specifically include, evaluation of the rapid binding of ACh to nAChRs, the activation and opening of nAChR channels, the duration of the nicotinic synaptic response and the return of the nAChRs to their resting state. In addition to these studies, primary cultures of central cholinergic neurons will be developed so that activation of nAChRs at pre- and post-synaptic sites can be examined directly. Synaptic transmission is the primary means through which neurons communicate and the output of a neuron is determined largely by integrating the varied incoming synaptic signals it receives. The particular features of a synaptic response, determined by the interaction between receptor and transmitter, will control the influence that signal will have on the overall properties of the neuron. Therefore, a knowledge of the fundamental characteristics of the synaptic activation of nAChRs by ACh would be invaluable in the understanding of both the normal function of the cholinergic system in synaptic transmission and plasticity, and the full implications of cholinergic neuronal loss in certain degenerative diseases.