Hippocampal Plasticity Induced by Patterned Stimulation

行为神经科学研究的一个主要目标是 识别神经生物学过程， 学习和记忆。 一个重要的考试模型系统 基于经验的神经元活动变化是长期的 增强或LTP。 这是一个相对持久的变化 突触的效率，这是刺激的结果， 一串短暂的高频微弱电脉冲 这种形式的"神经元可塑性"最早是在 海马结构，一个已知参与 记忆形成 罗斯博士最近的研究表明， 一种电刺激模式， 突出的电生理活动模式， 海马（复杂的尖峰放电和θ节律），他可以 显著降低诱导LTP的阈值。 这种效果， 被称为"引发爆发"（PB）增强，被调用相当 可靠地通过少至五个适当模式的刺激。 因为它的门槛低，而且它与知名的 电活动模式，它提出了一个PB样 在海马体形成过程中， 新的记忆 罗斯博士正在记录大脑的电生理活动 正常清醒大鼠的大脑皮层来评估这一假设。 这项工作澄清了生理和行为 促进PB增强的条件，从而表明其 在学习过程中的作用。 他也在研究 PB增强和记忆之间的相关性，通过检查 压力和衰老的影响（已知两种情况会损害 记忆功能）对海马突触 显示PB效果。

A major goal of behavioral neuroscience research is the identification of the neurobiological processes which underlie learning and memory. One important model system for examining experience-based changes in neuronal activity is long-term potentiation, or LTP. This is a relatively long-lasting change in the efficiency of synapses, which results from stimulation with a brief, high frequency train of weak electrical pulses. This form of "neuronal plasticity" was first discovered in the hippocampal formation, a brain region known to be involved in memory formation. Dr. Rose' recent work has shown that by using a pattern of electrical stimulation which mimics either of two prominent electrophysiological activity patterns of the hippocampus (complex spike discharge and theta rhythm), he could markedly reduce the threshold for inducing LTP. This effect, termed "primed burst" (PB) potentiation, is invoked quite reliably by as few as five appropriately patterned stimuli. Because of its low threshold, and of its similarity to well-known electrical activity patterns, it is proposed that a PB-like process may occur within the hippocampus during the formation of new memories. Dr. Rose is recording electrophysiological activity from the hippocampi of normal, awake rats to evaluate this hypothesis. This work is clarifying both the physiological and behavioral conditions which promote PB potentiation, thus suggesting their role in the learning process. He is also examining the correlation between PB potentiation and memory by examining the effects of stress and aging (two conditions known to impair mnemonic function) upon the capacity of hippocampal synapses to show this PB effect.