ANTIEPILEPTIC DRUG EFFECTS ON CA2+ AND GABA C1 CURRENT

这项研究的长期目标是更好地了解 抗癫痫药物治疗癫痫的作用机制 癫痫拟议的研究将集中在以下领域： 神经生理学、神经药理学和分子生物学。实验将 旨在研究抗癫痫药物对电压的基本作用 依赖性和递质门控离子通道。 电压依赖性钙通道将在小鼠和大鼠的原代细胞中进行研究。 以及中枢和初级传入神经的急性分离细胞培养物 神经元在这些组织中记录的钙电流成分包括 瞬态低阈值电流（T），大瞬态高阈值 电流（N）和缓慢失活的高阈值电流（L）。使用 全细胞电压钳技术，我们将确定所有的效果 临床使用的抗癫痫药物、活性代谢物，以及 戊四唑对T、N和L全细胞钙电流的影响。线性泄漏 并且电容电流将从记录的电流中减去， 通过分析峰值电流、激活和失活动力学、电压 依赖性，以及从失活恢复的时间过程。使用 细胞贴附单通道记录技术，我们将确定 电压依赖性T、N和L钙通道的特性以及 抗癫痫药物、活性代谢物和戊四氮的作用 单通道电流。记录的数据将被数字化和分析 通过计算机离线。单个电流将由 通道振幅分布、开放和关闭时间直方图， 突发特征，包括频率、持续时间、分布、数量 以及打开和关闭的类型和爆发间隔。 递质门控氯离子通道将在非洲爪蟾卵母细胞中进行研究， 细胞内记录技术注射和表达后， 分离或克隆的GABA A受体mRNA。单通道电流将为 在卵母细胞和急性和稳定的cDNA转染的哺乳动物中研究 细胞系重点将放在表征表达 受体对苯二氮卓类、巴比妥类和惊厥药物的反应 动力学性质分析。

The long term objective of this research is a better understanding of the mechanisms of action of antiepileptic drugs used in the treatment of epilepsy. The proposed studies will concentrate within the fields of neurophysiology, neuropharmacology and molecular biology. Experiments will be designed to study the basic action of antiepileptic drugs on voltage dependent and transmitter gated ion channels. Voltage dependent calcium channels will be studied in mouse and rat primary and acutely dissociated cell cultures of central and primary afferent neurons. The calcium current components recorded in these tissues include a transient low threshold current (T), a large transient high threshold current (N), and a slowly inactivating high threshold current (L). Using the whole cell voltage clamp technique, we will determine the effect of all clinically used antiepileptic drugs, active metabolites, and pentylenetetrazol on T, N, and L whole cell calcium currents. Linear leak and capacitance currents will be subtracted from recorded currents followed by analysis of peak currents, activation and inactivation kinetics, voltage dependency, and the time course of recovery from inactivation. Using the cell attached single channel recording technique, we will determine the properties of voltage dependent T, N, and L calcium channels and the effects of antiepileptic drugs, active metabolites, and pentylenetetrazol on single channel currents. Recorded data will be digitized and analyzed off line by computer. Individual currents will be analyzed by the distribution of channel amplitudes, open and closed time histograms and burst characteristics including frequency, duration, distribution, number and types of openings and closings, and interburst interval. Transmitter gated chloride channels will be studied in Xenopus oocytes by intracellular recording techniques after injection and expression of either isolated or cloned GABA A receptor mRNA. Single channel currents will be studied in the oocytes and in acutely and stably cDNA transfected mammalian cell lines. Emphasis will be placed on the characterization of expressed receptors' responses to benzodiazepines, barbiturates, and convulsant drugs and on the analysis of kinetic properties.