CHARACTERIZATION AND DEVELOPMENT OF A SEIZURE FOCUS

内科难治性颞叶畸形的外科治疗 脑叶癫痫表明至少有两种类型的大脑 移除可控制癫痫发作的病灶。在一节课上， 病灶局限于内侧颞叶，尤其是 海马体。过去资助期的调查显示 一些明显的变化表明有相当大的 这些海马区癫痫灶的化学构筑变化。确实有 本提案的三个主要目标。(1)进一步界定 这些病灶的神经化学组织，特别是与 非NMDA谷氨酸受体GluR1至GluR5的分布，以及 谷氨酸代谢性受体的原位杂交技术。 抑制性氨基酸γ-氨基丁酸-A受体 亚型Alpha1、Alpha2、Alpha3、Delta和Gamma 2也将 通过原位杂交技术定位，而GABA-B 用受体放射自显影定位受体。该地区 蛋白激酶C及其同工酶和肌醇的分布 三磷酸(IP3)，参与钙离子的第二信使系统 调节，将通过免疫细胞化学和受体定位 放射自显影。神经元和神经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， 并用[~3H]-胞苷掺入法研究其功能状态 在受体的药理刺激之后。(2)为了 检查癫痫灶上的神经元和神经胶质细胞是否存在固有的 经过改良，这些细胞在原代培养中建立起来的人 致痫组织，将进行电生理学研究以 测定它们的膜生物物理和离子通道活性，以及 研究了神经递质在神经胶质细胞上的表达。 神经胶质受体的功能状态将通过钙离子来评估。 受体刺激后的影像研究。(三)发展 热性惊厥后的海马神经元损伤将被追踪 在发热诱导的大鼠癫痫模型中。面临的关键时期 最大损伤与惊厥强度对癫痫发作程度的影响 损伤将通过银变性染色和TIMM进行评估 污渍。细胞损伤原因的线索将在 转录因子c-fos、c-fos早期表达的检测 Jun、B-Jun和ZIF/268以及神经生长因子(NGF)；在一项关于 皮质类固醇的作用；血脑屏障的破坏 根据血管内辣根渗漏的程度进行评估 在热性惊厥后，过氧化物酶进入脑实质。 这些研究加在一起应该会让我们更好地理解 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.