REGULATION OF THE GABA RECEPTOR-CHLORIDE ION CHANNEL

总体目标是确定监管的机制 大鼠脑内GABA受体/氯离子通道复合体。自.以来 异常的GABA能神经传递似乎是导致 癫痫发作障碍，调节“转导”成分(GABA 受体/氯离子通道)在GABA能传递中可能起重要作用 在病因和对癫痫发作活动的反应中的作用。两大 将使用生化工具来实现这些目标。其中一个涉及到 GABA受体门控C_1离子通道结合调节的研究 标记为(35S)Tbps的站点。另一项涉及对监管的研究。 GABA受体介导的~(36)Cl-离子通量。它的一个重要特点是 技术是它们可以在相同的组织中使用，来自相同的 动物在相同的条件下，这在 过去时。研究计划分为三个部分。第一个是 确定体外调节的细胞机制。中的更改 GABA受体/氯离子通道活性将在1)之后进行测量 减敏条件2)膜磷脂的变化 磷脂酶(即游离脂肪酸的释放和随后的形成 氧自由基和过氧化脂质)和3)暴露于磷酸化 条件。这些细胞过程在调节GABA中的作用 体内的受体复合体将在第二和第三部分中确定 研究计划的一部分。第二部分，敏感度的变化 GABA受体/氯离子通道的特性将在以下重复研究 大鼠暴露于已知的GABA受体复合体激动剂 下调GABA识别位点。这些在3点起作用的药物 GABA受体复合体上的不同部位包括GABA激动剂， 苯二氮卓类和巴比妥类。这些药物中的每一种都有抗惊厥的作用 活动。在第三部分中，研究旨在衡量 GABA受体/c1-离子通道活性在化学和 电诱导癫痫发作。作用于不同部位的惊厥药 GABA受体复合体(荷包牡丹碱和印防己毒素)和最大 电击将在10天内重复进行。这个 研究将提供对调控机制的新见解 细胞水平上的GABA能神经传递。这项研究应该 揭示这些机制在惊厥和抗癫痫作用中的重要性 抗惊厥药物和癫痫活动的生理学本身。

The overall objective is to determine the mechanisms of regulation of the GABA receptor/chloride (C1-) ion channel complex in rat brain. Since abnormal GABAergic neurotransmission appears to be a major factor in seizure disorders, regulation of the 'transducer' component (the GABA receptor/C1- ion channel) of GABA-ergic transmission may play an important role in the etiology and response to seizure activity. Two major biochemical tools will be used to achieve these objectives. One involves studies of the regulation of GABA receptor-gated C1- ion channel binding sites labeled with (35S)TBPS. The other involves studies of the regulation of GABA receptor-mediated 36C1- ion flux. An important feature of these techniques is that they can be used in the same tissue from the same animals under identical conditions, something that was not possible in the past. The research plan is divided into 3 parts. The first is to determine the cellular mechanisms of regulation in vitro. Alterations in GABA receptor/C1- ion channel activity will be measured subsequent to 1) desensitizing conditions 2) alterations in membrane phospholipids by phospholipases (i.e., release of free fatty acids and subsequent formation of oxygen radicals and lipid peroxides) and 3) exposure to phosphorylating conditions. The role of these cellular processes in regulating the GABA receptor complex in vivo will be determined in the second and third parts of the research plan. In the second part, alterations in the sensitivity of the GABA receptor/C1- ion channel will be studied following repeated exposure of rats to agonists off the GABA receptor complex which are known to down-regulate GABA recognition sites. These drugs which act at 3 distinct sites on the GABA receptor complex include GABA agonists, benzodiazepines and barbiturates. Each of these drugs has anticonvulsant activity. In the third part studies are designed to measure changes in GABA receptor/C1- ion channel activity following both chemically- and electrically-induced seizures. Convulsants which act at distinct sites on the GABA receptor complex (bicuculline and picrotoxin) and maximal electroshock will be administered repeatedly over a 10 day period. The studies will provide new insights into the mechanisms that regulate GABAergic neurotransmission on a cellular level. This research should reveal the importance of these mechanisms in the actions of convulsant and anticonvulsant drugs and in the physiology of seizure activity itself.