SYNAPTIC MODULATION IN SMALL NEURAL NETWORKS

神经系统的发育和可塑性涉及到活动-- 突触连接的依赖性修饰。我们最近做了 证明了重复训练引起的长期抑郁(LTD 在一个突触处的突触活动伴随着广泛但选择性的 抑郁的传播到网络中的其他突触。这个 这项第三年提案的目标是进一步检查病毒的传播 神经网络中的突触信号。目标1中的实验是 旨在将目前的研究扩展到包括突触修饰 与长时程增强(LTP)的诱导有关。 目标2中的实验将确定来自多个 神经元的输出/输入可以在空间和/或时间上集成。 为了研究突触修饰的传播，我们利用 一种密度很低的原代培养系统，其中三四个人组成一组 海马神经元(三胞胎或四胞胎)与一个 另一种与培养中的其他神经元相对隔离的细胞可以是 通常会被发现。主要是电生理方法，使用 来自定义的神经网络的多个全细胞记录将用于 建议进行的研究。这项研究有望提供新的信息。 关于活动诱导突触的选择性分布 一种简单的生物神经网络内部修改，具有广泛的应用前景 对理解潜在的细胞机制的影响 中枢神经系统的学习过程。

The development and plasticity of the nervous system involve activity- dependent modification of synaptic connections. We have recently demonstrated that long-term depression (LTD) induced by repetitive synaptic activity at one synapse is accompanied by extensive but selective propagation of the depression to other synapses within the network. The goal of this third year proposal is to further examine the spread of synaptic signals within a neural network. Experiments in Aim 1 are designed to extend the present studies to include synaptic modifications associated with the induction of long-term potentiation (LTP). Experiments in Aim 2 will determine whether the influences from multiple outputs/inputs of a neuron can be spatially and/or temporally integrated. To study the propagation of synaptic modification, we have taken advantage of a very low density primary culture system where groups of three or four hippocampal neurons (triplets or quadruplets) that are connected with one another but relatively isolated from other neurons in the culture can be routinely found. Primarily electrophysiological approaches, using multiple whole-cell recording from defined neural networks, will e used in the proposed studies. This research promises to yield novel information concerning the selective distribution of activity-induced synaptic modification within a simple biological neural network, which has broad implications for understanding the cellular mechanisms underlying the learning processes of the central nervous system.