ASSOCIATIVE SYNAPTIC PLASTICITY

关联性突触可塑性

• 批准号: 3411263
• 负责人: Thomas W Abrams
• 金额: $ 13.74万
• 依托单位: UNIVERSITY OF PENNSYLVANIA
• 依托单位国家: 美国
• 财政年份: 1988
• 资助国家: 美国
• 起止时间: 1988-06-15 至 1993-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3411263
• 关键词: Gastropoda; adenylate cyclase; afferent nerve; association learning; calcium metabolism; calcium transporting ATPase; chromatography; conditioning; cyclic AMP; electrophysiology; hippocampus; neural initiation; neural plasticity; neurochemistry; phosphorylation; reflex; stimulus /response; synapses

The long range goal of this research is to understand the cellular mechanisms by which associations are made during learning. The marine snail Aplysia provides an advantageous model system for the analysis of simple forms of learning because of its nervous system with neurons that are relatively few in number, large and uniquely identifiable. Classical conditioning of the defensive withdrawal reflex of Aplysia resembles conditioning in vertebrates in a number of respects. An associative form of synaptic plasticity, activity-dependent synaptic facilitation, which occurs within single sensory neurons in the conditioned stimulus pathway, plays an important role in the associative changes produced by conditioning. The specific aim of this proposed study is to analyze how spike activity in a sensory neuron, which is triggered by the conditioned stimulus, enhances the cell's synaptic facilitation response to modulatory input that produced during training by the unconditioned stimulus. The enzyme adenylate cyclase in the sensory neuron has been shown to provide a molecular site of associative interaction between Ca2+ influx, which accompanies the cell's own spike activity, and modulatory transmitter. Neurophysiological studies on intact sensory neurons will be carried out to critically evaluate the role of adenylate cyclase in activity-dependent facilitation. Biochemical studies will attempt to analyze how the two inputs, Ca2+ influx and modulatory transmitter, interact in activating the cyclase. Activity-dependent facilitation has some striking similarities with associative long-term synaptic potentiation in mammalian hippocampus and with activity-dependent tuning of synaptic connections that occurs in the developing vertebrate visual system. A thorough understanding of this form of activity- dependent synaptic plasticity may aid in our understanding of other types of activity-dependent neural changes during learning and during development.

这项研究的远距离目标是了解细胞 在学习过程中建立关联的机制。 这 海洋蜗牛Aplysia提供了一个有利的模型系统 由于其紧张而对简单的学习形式的分析 具有相对较少数量的神经元的系统 独特的可识别。 防御的经典条件 Aplysia的提款反射类似于调节 脊椎动物在许多方面。 一种联想形式 突触可塑性，活动依赖性突触促进， 发生在条件的单个感觉神经元中 刺激途径，在关联中起重要作用 调节产生的变化。 这个的具体目的 拟议的研究是分析如何在感觉中的峰值活性 由条件刺激触发的神经元增强 细胞对调节输入的突触促进反应 通过无条件刺激在训练期间产生。 这 感觉神经元中的酶腺苷酸环化酶已显示为 提供CA2+之间的关联相互作用的分子位点 涌入，伴随细胞自身的尖峰活动，以及 调节发射器。 完整的神经生理研究 感觉神经元将进行批判性评估角色 活性依赖性促进中的腺苷酸环化酶的。 生化研究将尝试分析两个投入如何 Ca2+涌入和调节发射器，在激活中相互作用 循环酶。 与活动有关的促进作用与 哺乳动物的关联长期突触增强 海马并与突触的活性依赖性调整 发育中的脊椎动物视觉上发生的连接 系统。 对这种活动形式的透彻理解 - 依赖的突触可塑性可能有助于我们理解 学习过程中其他类型的活动依赖性神经变化 并在发展过程中。