CELLULAR MECHANISMS OF INHIBITORY TRANSMISSION

本提案的总体目标是研究神经生物学， 哺乳动物抑制性突触传递的神经药理学 中枢神经系统我们的研究将致力于定义一些 GABA能神经传递的细胞机制。主要目标是 至：1.定义神经活性丁内酯的作用， 调节GABA电生理效应的相关化合物; 2.确定GABA对细胞内pH可能的调节作用， 游离钙浓度;和3.阐明...的一些特点 突触前GABA释放我们的实验将用海马 从新生大鼠培养的神经元，并将利用全细胞记录 电流箝位或电压箝位模式的技术。的结果 这些实验应该能提高我们对 由大脑来限制电活动的传播，并可能有助于 治疗癫痫和其他疾病的药物 神经系统疾病 具体而言，我们计划： 1a.检查项目1和2中描述的许多化合物，以确定 它们是否是受体激动剂（减少GABA介导的氯化物 电流），反向激动剂（增强GABA介导的氯电流）， 拮抗剂（阻断激动剂和反向激动剂，而不具有直接 对GABA电流的影响），或无活性（在GABA受体）。 1b.检查丁内酯和其他已知的化合物之间的相互作用， 作用于GABA（A）受体（GABA（A）激动剂，苯二氮卓类，和 巴比妥酸盐）。 1c.确定丁内酯是否上调或下调GABA（A）受体 在培养的海马神经元中。 2.确定GABA是否可以直接改变pH或细胞内钙 培养的海马神经元。 3a.从生理学上估计实际释放的GABA浓度， 抑制性突触 3b.确定中枢神经系统中GABA的释放是否总是 取决于钙的进入。

The overall objective of this proposal is to study the neurobiology and neuropharmacology of inhibitory synaptic transmission in the mammalian central nervous system. Our studies will be directed toward defining some of the cellular mechanisms of GABAnergic neurotransmission. Major goals are to: 1. define the role(s) of neuroactive butyrolactones and chemically related compounds in modulating the electrophysiological effects of GABA; 2. identify possible modulatory effects of GABA on intracellular pH and free calcium concentration; and 3. elucidate some characteristics of presynaptic GABA release. Our experiments will be done with hippocampal neurons cultured from neonatal rats and will utilize whole cell recording techniques in either current-clamp or voltage-clamp mode. The results of these experiments should improve our understanding of the mechanisms used by the brain to limit the spread of electrical activity and may help in the development of better drugs for the treatment of epilepsy and other neurological disorders. Specifically, we plan to: 1a.Examine many of the compounds described in Projects 1 and 2 to ascertain whether they are receptor agonists (diminish GABA-mediated chloride currents), inverse agonists (enhance GABA-mediated chloride currents), antagonists (block agonists and inverse agonists without having a direct effect on GABA currents), or inactive (at the GABA receptor). 1b.Examine interactions between butyrolactones and other compounds known to act at the GABA(A) receptor (GABA(A) agonists, benzodiazepines, and barbiturates). 1c.Determine whether butyrolactones up- or down-regulate GABA(A) receptors in cultured hippocampal neurons. 2.Determine whether GABA can directly alter the pH or intracellular calcium of cultured hippocampal neurons. 3a.Physiologically estimate the concentration of GABA actually released at inhibitory synapses. 3b.Determine whether GABA release in the central nervous system is always dependent on calcium entry.