MICROANATOMY OF HUMAN EPILEPTIC HIPPOCAMPAL FORMATION

颞叶癫痫（TLE）是成人癫痫最常见的形式， 顽固性癫痫发作，可以手术治疗。这个实验室， 在我们的NIH项目中研究人类TLE的临床病理学， 已经表明：1）使用定量技术，海马损伤，称为 海马硬化（HS）是最常见的（65%）， 标准化的手术标本来自于局灶性TLE患者。2)HS 包括特定量和模式的神经元损失，其相对 特异于癫痫性脑脊髓炎，在其他疾病中不重复。 3)HS区域与显著的异常轴突发芽相关 以及兴奋性苔藓纤维（MF）和 抑制GABA系统，特别是在齿状筋膜（FD）。4)尽管 显著的细胞丢失，这些HS战神和突触重组 是癫痫发作的区域这些数据导致了一种假设 重组的轴突回路，特别是在FD中， 海马体癫痫发作这些异常的轴突回路 反馈和前馈，可以解释为什么一个神经元贫乏的区域 会导致癫痫发作轴突回路重塑的存在并不意味着 表明突触后受体也有相应的变化 以及它们的mRNA在新的靶神经元中的作用。为了让FD 过度兴奋，应该有变化的数量和类型， 轴突发芽区域的兴奋性和抑制性受体。在 FD，已经假设最里面的重组MF 颗粒上区是谷氨酸能兴奋性的， 轴突是抑制性的。我们的研究将使用新建立的分子 用寡核苷酸探针进行原位杂交（ISH）技术， 除了已经建立的免疫细胞化学（ICC）和组织化学 技术，以测试以下可拒绝的假设：1）在 FD的癫痫颗粒上层，发芽反馈神经递质 MF将与兴奋性神经元的显著差异性增加有关。 受体亚型沿着其mRNA的上调。2)在同一 FD区，颗粒上GABA终末出芽， 颗粒层不会显著地与 抑制性GABA受体亚型沿着及其mRNA。3)颗粒中 细胞，谷氨酸受体将有从FLOP到FLIP的基因组变化 （更长的去极化）。我们的方法将客观地衡量和 用图像分析计算机量化结果。结果将 在统计学上与尸检和手术标本的尸检结果相比， 颞叶肿瘤，这是最好的控制比较， 人体实验同样重要的是，许多ICC和ISH研究 将尽可能在每个人的海马体上进行， 患者和生物变量之间的比较，以及与 计划项目的其他子项目。这些研究将提供 深入了解HS的分子病理生理学，并提出重要的 这种形式的顽固性局灶性癫痫的致病机制。

Temporal lobe epilepsy (TLE) is the most frequent form of adult intractable seizures and is surgically treatable. This laboratory, studying the clinical pathology of human TLE in our NIH Program Project, has shown that: 1) Using quantified techniques, hippocampal damage, termed hippocampal sclerosis (HS), is the most frequent (65%) finding in standardized surgical specimens from patients with focal TLE. 2) HS comprises a specific amount and pattern of neuron loss that is relatively specific for epileptic hippocampi and is not duplicated in other diseases. 3) The areas of HS are associated with significant aberrant axon sprouting and neosynaptogenesis of the excitatory mossy fibers (MF) and of the inhibitory GABA system, especially in the fascia dentata (FD). 4) Despite the significant cell loss, these ares of HS and synaptic reorganizations are the regions of seizure onsets. These data have lead to the hypothesis that the reorganized axon circuits, especially in the FD, are mechanisms for hippocampal seizure onsets. These aberrant axon circuits are both feedback and feedforward and could explain how an area that is neuron poor can generate seizures. The presence of remodeled axon circuits does not indicate that there are concomitant changes in the postsynaptic receptors and their mRNAs in the new target neurons. In order for the FD to be hyperexcitable, there should be changes in the amount and type of excitatory and inhibitory receptors in the area of axon sprouting. In the FD, it has been assumed that the reorganized MFs in the innermost supragranular region are glutamatergic excitatory, and the sprouted GABA axons are inhibitory. Our research will use newly established molecular techniques of in situ hybridization (ISH) with oligonucleotide probes, in addition to already established immunocytochemical (ICC) and histochemical techniques, to test the following rejectable hypotheses: 1) In the epileptic supragranular layer of the FD, sprouted feedback glutamatergic MFs will relate to significant differential increases in excitatory receptor subtypes along with upregulation of their mRNAs. 2) In the same region of the FD, sprouting of the GABA terminals in the supragranular and granular layers will not significantly relate to increases in the inhibitory GABA receptor subtypes along with their mRNAs. 3) In granule cells, glutamate receptors will have genomic changes from FLOP to FLIP (longer depolarizations). Our methods will objectively measure and quantify the results with an image analysis computer. The results will be statistically compared to autopsies and hippocampi from surgical specimens with temporal tumors, which are the best available control comparisons for human experimentation. Just as importantly, as many ICC and ISH studies will be performed as possible on each human hippocampus to maximize comparisons between patients and biological variables, and compared to other subprojects of the program project. These studies will provide insight into the molecular pathophysiology of HS and suggest important pathogenic mechanisms of this form of intractable focal epilepsy.