STUDY OF THE INHIBITORY RESPONSE OF GABA DURING CARDIOREGULATION IN LIMULUS

本项目的长期目标是阐明心脏抑制 在心脏调节中的作用。 γ-氨基丁酸 （GABA）和5-羟色胺（5-HT）都被认为是 美洲鲎中枢神经内的心脏抑制性递质 系统（CNS）。 γ-氨基丁酸的确切生理作用， 心脏抑制没有解决。 在我们努力阐明神经控制的过程中 抑制在中枢神经系统的美洲鲎，我们假设，GABA 在鲎的中枢神经系统中与5-HT共存，作为神经递质， GABA在心脏调节过程中有助于抑制反应， 中枢和外周神经系统。 我们建议确定GABA能 用免疫细胞化学方法观察鲎中枢神经系统内神经元的变化。 的 免疫反应性胞体和纤维的鉴定 somata。 印防己毒素和荷包牡丹碱的拮抗作用将是 电生理学评估，对GABA抑制反应， 爆发频率、爆发内容（尖峰/爆发）和爆发分析 持续时间 我们建议进一步表征GABA能 受体在鲎中枢神经系统与使用激动剂和拮抗剂。 GABA摄取和释放的动力学和药理学研究 是鲎中公认抑制性神经递质， 中枢和外周神经系统的心脏调节。

The long range objectives of this project is to clarify cardioinhibition during cardioregulation in Limulus polyphemus. Gamma-aminobutyric acid (GABA) and 5-hydroxytryptamine (5-HT) both have been implicated as cardioinhibitory transmitters within Limulus polyphemus Central Nervous System (CNS). The precise physiological role played by GABA in cardioinhibition is not settled. In our effort to clarify neural control of inhibition in the CNS of Limulus polyphemus, we hypothesize that GABA co-exists with 5-HT in the CNS of Limulus as a neurotransmitter, and that GABA aids in a inhibitory response during cardioregulation in both the central and peripheral nervous system. We propose to identify GABAergic neurons within the CNS of Limulus by using immunocytochemistry. The identification of immunoreactive somata and fibers to immunoreactive somata. The antagonistic action of picrotoxin, and bicuculline will be assessed electrophysiologically, on GABA inhibitory response during analysis of burst frequency, burst content (spikes/burst), and burst duration. We propose to further characterize pharmacologically GABAergic receptors within Limulus CNS with the use of agonists and antagonists. Kinetics and pharmacological studies on the uptake and release of GABA is putative inhibitory neurotransmitter in Limulus and function in cardioregulation both in the central and peripheral nervous system.