FUNCTIONAL SIGNIFICANCE OF HIPPOCAMPAL SPROUTING

描述(改编自调查者摘要) 已经在死后观察到海马结构中的神经元萌发 患有阿尔茨海默病的患者。存在这样一种可能性，即 海马环路的重组可能：1)有助于行为 与疾病相关的症状，或2)补偿 海马神经元投射到海马区。不幸的是，几乎没有 目前所知的在中央萌芽的行为意义 神经系统(CNS)。这次小规模调查的目的是 评价脑齿状回发芽的功能意义 大鼠单侧内嗅皮质损伤后的海马区结构 老鼠。这项研究将集中在一个增殖的突触效能 之后的同源输入(即，交叉临时齿投影-CTD) 一期或进展性EC病变。已知进行性EC病变 促进隔齿、连合/联合和CTD萌发到 齿状回；然而，进行性损害对能力的影响 支持长时程增强和成对脉冲增强的CTD，有两个 突触功效的测量方法尚不清楚。萌发的CTD途径是 特别有趣的原因是：1)它出现在 对侧同源物作为正常同侧内嗅觉输入到 齿状回；2)它与空间记忆的恢复有关 在单侧内嗅觉损伤后。特别值得注意的，进步的 内嗅区的损伤已经被证明可以节省空间记忆 缺陷通常与内脏损伤有关。这种电生理学 分析将为未来的功能评估工作奠定基础 中枢神经系统发芽的意义。

DESCRIPTION (Adapted from the Investigator's Abstract) Neuronal sprouting has been observed post-mortem in the hippocampal formation of patients suffering from Alzheimer's disease. The possibility exists that the reorganization of hippocampal circuitry may: 1) contribute to the behavioral symptoms associated with the disease, or 2) compensate for the loss of hippocampal neurons projecting to the hippocampus. Unfortunately, little is presently known about the behavioral significance of sprouting in the central nervous system (CNS). The purpose of this small-scale investigation is to evaluate the functional significance of sprouting in the dentate gyrus of the hippocampal formation after unilateral lesions of the entorhinal cortex in rats. This study will focus on the synaptic efficacy of a proliferated homologous input (i.e., the crossed temporodentate projection - CTD) after a one stage or progressive EC lesion. Progressive EC lesions are known to accelerate septodentate, commissural/associational, and CTD sprouting to the dentate gyrus; however, the effects of the progressive lesions on the ability of the CTD to support long term potentiation and paired-pulse potentiation, two measures of synaptic efficacy, are unknown. The sprouted CTD pathway is of special interest because: 1) it emerges from the same cell layer in the contralateral homologue as the normal ipsilateral entorhinal input to the dentate gyrus; and, 2) it has been implicated in the recovery of spatial memory after unilateral entorhinal injury. Particularly noteworthy, progressive lesions of the entorhinal area have been shown to spare spatial memory from the deficits typically associated with entorhinal injury. This electrophysiological analysis will lay the foundation for future work assessing the functional significance of CNS sprouting.