CHARACTERIZATION AND DEVELOPMENT OF A SEIZURE FOCUS

难治性颞叶肿瘤的手术治疗 脑叶癫痫表明至少有两类大脑 病灶的清除可控制癫痫发作。在一个类中， 焦点局限于内侧颞叶，特别是 海马体。过去一段时间的调查显示， 一些明显的变化表明， 这些海马癫痫病灶的化学结构变化。有 本提案的三大目标。(1)以进一步限定 这些病灶的神经化学组织，特别是与 非NMDA谷氨酸受体GluR 1至GluR 5的分布， 谷氨酸代谢型受体的研究。 抑制性氨基酸γ-氨基丁酸-A（GABA-A）受体 亚型α 1、α 2、α 3、δ和γ 2亚基也将 通过原位杂交技术定位，而GABA-B 用受体放射自显影术定位受体。区域 蛋白激酶C（PKC）及其同工酶和肌醇的分布 三磷酸盐（IP 3），第二信使系统参与钙 调节，将与免疫细胞化学和受体定位 放射自显影神经元和胶质细胞上受体的细胞定位 将用荧光激动剂或拮抗剂分子探针进行研究， 并通过[3 H]-胞苷掺入探索其功能状态 在受体的药理学刺激之后。(2)为了 检查癫痫病灶处的神经元和神经胶质细胞是否在本质上 经修饰，这些细胞在原代培养中从人 致癫痫组织，将进行电生理学研究， 确定其膜生物物理学和离子通道活性，以及 以生物化学的方法研究神经胶质细胞上神经递质的表达。 神经胶质受体的功能状态将通过钙离子浓度来评估。 受体刺激后的成像研究。(3)的发展 将随访热性惊厥后海马神经元损伤 在大鼠发热诱发的癫痫发作模型中。的关键时期 最大损伤以及癫痫发作强度对癫痫程度的影响 损伤将通过银变性染色和Timm 污点细胞损伤原因的线索将在一个 检测转录因子c-fos、c-fos、c-fos和c-fos的早期表达， jun，B-jun和zif/268，以及神经生长因子（NGF）;在一项研究中， 皮质类固醇的作用;以及血脑屏障的破坏 通过血管内辣根的渗漏程度进行评估 过氧化物酶进入脑实质后发热诱导癫痫发作。 这些研究加在一起应该能让我们更好地理解 颞叶癫痫的病理生理学和病因学。

The surgical management of patients with medically intractable temporal lobe epilepsy has shown that there are at least two classes of brain foci the removal of which produces seizure control. In one class, the focus is confined to the medial temporal lobe, particularly the hippocampus. Investigations in the past period of funding have revealed a number of distinct changes indicative of considerable chemoarchitectural changes at these hippocampal seizure foci. There are three broad aims in the present proposal. (1) To further define the neurochemical organization of these foci particularly in relation to the distribution of non-NMDA glutamate receptors GluR1 to GluR5, and the glutamate metabotropic receptor using in situ hybridization techniques. The inhibitory amino acid Gamma Aminobutyric Acid-A (GABA-A) receptor subtypes alpha 1, alpha2, alpha3, delta and gamma 2 subunits will also be localized by in situ hybridization techniques, while the GABA-B receptor is localized with receptor autoradiography. The regional distribution of protein kinase C (PKC) and its isoenzymes, and inositol triphosphate (IP3), second messenger systems involved in calcium regulation, will be localized with immunocytochemistry and receptor autoradiography. The cellular location of receptors on neurons and glia will be studied with fluorescent agonist or antagonist molecular probes, and their functional state explored by [3H]-cytidine incorporation following pharmacological stimulation of receptors. (2) In order to examine if neurons and glia at seizure foci have been intrinsically modified, these cells in primary culture established from human epileptogenic tissue, will be studied electrophysiologically to determine their membrane biophysics and ion channel activity, and studied biochemically to measure neurotransmitter expression on glia. The functional state of glial receptors will be assessed by calcium imaging studies following receptor stimulation. (3) The development of hippocampal neuronal injury following febrile seizures will be followed in a fever induced seizure model in the rat. The critical period for maximal injury and the effect of seizure intensity on the degree of injury will be assessed by silver degeneration stains and the Timm stain. Clues to the causes of cellular injury will be sought in an examination of the early expression of transcription factors c-fos, c- jun, B-jun and zif/268, and nerve growth factor (NGF); in a study of the role of corticosteroids; and the disruption of the blood brain barrier assessed by the degree of leakage of intravascular horseradish peroxidase into the brain parenchyma following fever induced seizures. These studies together should give us a better appreciation of the pathophysiology and etiology of temporal lope epilepsy.