BEHAVIORAL AND PLACE CORRELATES OF HIPPOCAMPAL NEURONS

这个项目的广泛的长期目标是描述 认知功能中海马神经活动的本质 有助于学习和记忆 这些知识将有助于 我们对记忆障碍的神经基础的理解 结果是衰老和疾病中的大脑系统功能障碍。 该项目有两个具体目标：1）澄清 海马放电的基本功能相关 大鼠执行记忆任务的神经元，2）描述 海马中这些相关物的地形组织 皮层 所提出的实验设计利用了新的方法， 慢性单位记录，以将锋电位活动与感觉和 辨别学习和空间导航中的行为事件 表现取决于海马通路的任务。 包括生理和行为的计算机分析 测量将被用来揭示穗的最佳相关性 活动到关键任务事件。 将特别注意 单位活动在多大程度上可以用两个 在先前对海马单元的描述中突出的参数， “行为”参数，包括刺激和反应的学习 重要性，相对于“地方”或allocentric空间位置的 动物 比较同一细胞的放电相关性， 在每个任务内的参数之间，以及在单独的任务之间， 可以用来推断高阶功能属性共同 跨任务变化。 根据神经心理学数据，我们 工作假设是，这些高阶属性将 反映了海马神经元对刺激结构的编码。 具体的实验将集中在1）识别 反映任务事件配置的功能相关性，2） 这些相关因素的发展， 学习，和3）他们的消失后，断开连接， 海马通路 拟议的实验涉及记录从几个单一的- 同时使用两种不同类型的多通道的单元 微电极 这些方法不仅可以提高 数据收集的效率，但也将允许探索 的解剖组织的功能相关， 海马体。 分析将侧重于功能的比较 主要海马区之间的相关性和比较 近距离和远距离的相邻细胞之间同时记录。 这些分析将用于生成和确认 关于加工机制的假设反映在 单个神经元的功能相关性。

The broad, long-term objective of this project is to describe the nature of hippocampal neural activity in cognitive functions subserving learning and memory. This knowledge will contribute to our understanding of the neurological basis of memory disorders consequent to hippocampal-system dysfunction in aging and disease. There are two specific aims of the project: 1) to clarify the basic functional correlates of firing in hippocampal principal neurons in rats performing memory tasks, and 2) to describe the topographical organization of those correlates in the hippocampal cortex. The proposed experimental design exploits new methods in chronic unit recording to correlate spike activity with sensory and behavioral events in discrimination learning and spatial navigation tasks for which performance is dependent on hippocampal pathways. Computerized analyses involving physiological and behavioral measures will be used to uncover the optimal correlate of spike activity to key task events. Particular attention will be paid to the degree to which unit activity can be explained by two parameters prominent in previous descriptions of hippocampal units, "behavioral" parameters, including stimuli and responses of learned significance, versus "place" or allocentric spatial position of the animal. Comparison of the firing correlates for the same cell both across parameters within each task, and across separate tasks will be used to infer the higher-order functional attributes common across task variations. Based on neuropsychological data, our working hypothesis is that these higher order attributes will reflect encoding of stimulus configurations by hippocampal neurons. Specific experiments will focus 1) on the identification of functional correlates reflecting configurations of task events, 2) on the development of these correlates during the course of learning, and 3) on their disappearance after disconnection of hippocampal pathways. The proposed experiments involve recording from several single- units simultaneously using two different kinds of multichannel microelectrode. These methods will not only increase the efficiency of data collection, but will also permit an exploration of the anatomical organization of functional correlates within the hippocampus. Analyses will focus on comparisons of the functional correlates among the major hippocampal regions and on comparisons among near and distant neighboring cells recorded simultaneously. These analyses will be used both to generate and to confirm hypotheses about the processing mechanisms reflected in the functional correlates of individual neurons.