ELECTROPHYSIOLOGY OF RETROHIPPOCAMPAL NEURONS

海马体结构可分为两个回路的神经元。 解剖联系的基础和行为的相关性 细胞的激发。“阿蒙之角电路”是一种本质上 内嗅皮质兴奋性神经元的单向环 通过齿状回，阿蒙角(所谓的三突触 途径)和下丘脑。内嗅觉神经元、阿蒙氏角神经元和束下神经元 已知的是当动物处于特定的 记录环境中的位置(放置单元格)。在这些地区， 已经检查过的“丘前回路”(丘前， 下丘脑后核、部分丘脑前核和脾后皮质)， 当动物面对特定的环境时，神经元就会产生动作电位 记录环境内的方向(磁头方向单元)。 本项目将检查三个海马后区的电生理学。 区域：a)前下丘和后下丘(头部方向细胞的成员 电路)；b)下丘(放置单元电路的成员)；以及c) 内嗅皮层(控制信息流的结构 两个赛道)。 单个神经元的电生理特性及其局部 连通性及其对下丘脑前/后的贡献 内嗅器到下丘脑的通路将在切片和 麻醉的动物。其目的将是：a)描述 电生理上未定义的亚支复合体；b)识别 双突触通路中的特定神经元元件 在两个不同的边缘系统电路之间传输信息；以及c) 为解释录音提供电生理学标准 其他制剂，如来自自由行为的细胞外单位数据 动物。 这项工作对理解导航很重要，导航是一种 常常迷失在痴呆症中。此外，因为所有来自 海马体结构穿过下丘脑或内嗅觉皮质， 这项工作将对理解病毒的传播具有重要意义 癫痫对大脑其他部位的活动。

The hippocampal formation can be divided into two circuits of neurons on the basis of anatomical connections and the behavioral correlates of firing of cells. The "Ammon's horn circuit" is an essentially unidirectional loop of excitatory neurons from the entorhinal cortex (EC) through the dentate gyrus, Ammon's horn (the so-called tri-synaptic pathway), and subiculum. Entorhinal, Ammon's horn and subicular neurons are known to fire action potentials when the animal is in a particular location in the recording environment (place cells). In those parts of the "presubicular circuit" that have been examined (presubiculum, postsubiculum, some anterior thalamic nuclei and retrosplenial cortex), neurons fire action potentials when the animal faces a particular direction within the recording environment (head direction cells). This project will examine the electrophysiology of three retrohippocampal regions: a) the pre and postsubiculum (members of the head direction cell circuit); b) the subiculum (member of the place cell circuit); and c) the entorhinal Cortex (the structure that controls information flow between the two circuits). The electrophysiological properties of single neurons, their local connectivity and their contributions to the pre-/postsubiculum to entorhinal to subiculum pathway will be studied in slices and in anesthetized animals. The purpose will be to: a) characterize the cells of the electrophysiologically undefined subicular complex; b) identify the specific neuronal elements in the disynaptic pathway that serves to transfer information between two distinct limbic system circuits; and c) to provide electrophysiological criteria for interpreting recordings from other preparations such as extracellular unit data from freely behaving animals. This work is important in the understanding of navigation, a function that is frequently lost in dementias. Also, because all output from the hippocampal formation goes through the subiculum or the entorhinal cortex, this work will be important in the understanding of the spread of epileptic activity to other parts of brain.