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.

这项研究的长期目标是了解细胞 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 分析简单的学习形式，因为它很紧张 神经元数量相对较少、较大且较小的系统 唯一可识别的。 防守的经典调理 海兔的撤退反射类似于条件反射 脊椎动物在许多方面。 一种关联形式 突触可塑性，活动依赖性突触促进， 它发生在条件反射中的单个感觉神经元内 刺激通路在联想中起重要作用 条件作用产生的变化。 此次活动的具体目的 拟议的研究是分析感官中的尖峰活动如何 神经元由条件刺激触发，增强 细胞对调节输入的突触促进反应 训练期间由无条件刺激产生的。 这 感觉神经元中的腺苷酸环化酶已被证明 提供 Ca2+ 之间缔合相互作用的分子位点 流入，伴随着细胞自身的尖峰活动，以及 调制发射机。 完整神经生理学研究 感觉神经元的作用将被严格评估 腺苷酸环化酶在活性依赖性促进中的作用。 生化研究将尝试分析这两种输入如何， Ca2+ 流入和调节递质相互作用，激活 环化酶。 活动依赖性促进与以下有一些惊人的相似之处： 哺乳动物的联想长期突触增强 海马体和突触的活动依赖性调节 脊椎动物视觉发育过程中发生的连接 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 以及开发过程中。