Pregnenolone Sulfate Inhibition of GABA Current

硫酸孕烯醇酮对 GABA 电流的抑制

• 批准号: 6867339
• 负责人: Lawrence N Eisenman
• 金额: $ 15.9万
• 依托单位: WASHINGTON UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-03-15 至 2009-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6867339
• 关键词: GABA receptor; Xenopus oocyte; allosteric site; chemical kinetics; computational biology; computer simulation; electrophysiology; gamma aminobutyrate; hippocampus; hormone regulation /control mechanism; inhibitor /antagonist; laboratory rat; ligands; membrane channels; model design /development; mutant; neural transmission; partial seizure; postdoctoral investigator; pregnenolone; receptor binding; receptor expression; receptor sensitivity; temporal lobe /cortex disorder; tissue /cell culture; voltage /patch clamp; zinc

DESCRIPTION (provided by applicant): This is an application for a Mentored Clinical Scientist Development Award (K08) from NINDS. The applicant is completing training as an Epilepsy specialist, and is interested in understanding the behavior of networks of neurons in normal and pathological conditions. The applicant has previous experience using computer models and wishes to learn the complementary experimental techniques in order to pursue this interest with a combination of theoretical and experimental approaches. The long-term goal is to achieve insight into the pathophysiology of epilepsy in order to be able to better treat patients. The goal of this award is to acquire the skills and experimental techniques necessary to become an independent investigator. The goal of the proposed studies is to explore the role of pregnenolone sulfate (PS) in the modulation of inhibitory synaptic transmission. PS, one of the more common steroids in the central nervous system (CNS) inhibits GABA receptor-mediated currents. PS is present in the CNS at high nanomolar concentrations, but the effective concentration had been thought to be in the micromotar range suggesting that PS does not cause physiologically relevant modulation. However, our preliminary data suggest that PS inhibition of GABA receptor-mediated currents is activation-dependent, requiring activation of receptors in order for modulation to occur. Activation dependence may allow modulation at PS concentrations lower than previously appreciated. The objective of this proposal is to further characterize the properties of PS inhibition of GABA receptors. Experiments designed to explore the relative importance of ligand binding and channel opening for optimal PS effect, define the kinetic properties of a PS insensitive mutant GABA receptor and compare the properties of PS inhibition to those of zinc, an important endogenous GABA modulator, will be performed using Xenopus oocytes expressing GABA receptors and native receptors in hippocampal microisland cultures and acute hippocampus slices. Computational modeling will be employed to provide a theoretical foundation to facilitate interpretation of the data. Appreciation of the properties of PS inhibition may result in a better understanding of the conditions under which PS may be an important endogenous modulator of GABA currents and provide insight into the underlying properties of GABA receptors.

描述（由申请人提供）：这是Ninds的指导临床科学家发展奖（K08）的申请。申请人正在以癫痫专家的身份完成培训，并有兴趣了解正常和病理条件下神经元网络的行为。申请人以前有使用计算机模型的经验，并希望学习补充实验技术，以通过理论和实验方法的结合来追求这种兴趣。长期目标是深入了解癫痫病理生理学，以便能够更好地治疗患者。该奖项的目的是获取成为独立研究者所需的技能和实验技术。拟议的研究的目的是探索硫酸妊娠硫酸盐（PS）在抑制性突触传播调节中的作用。 PS是中枢神经系统（CNS）中最常见的类固醇之一，抑制了GABA受体介导的电流。 PS存在于CNS中的高纳摩尔浓度，但认为有效浓度在微摩托范围内，这表明PS不会引起生理相关的调节。但是，我们的初步数据表明，PS抑制GABA受体介导的电流是激活依赖性的，需要激活受体才能进行调节。激活依赖性可能允许在PS浓度低于先前所欣赏的PS浓度下调节。该建议的目的是进一步表征PS抑制GABA受体的特性。旨在探索配体结合和通道开放以实现最佳PS效应的相对重要性的实验，定义PS不敏感的突变体GABA受体的动力学特性，并将PS抑制与锌的特性（使用Xenopus oocyter oocyters MICAIRS受体进行）进行，将PS抑制与锌的抑制作用进行比较。海马切片。计算建模将用于提供理论基础，以促进数据的解释。对PS抑制的性质的欣赏可能会更好地理解PS可能是GABA电流的重要内源性调节剂的条件，并提供对GABA受体的潜在特性的见解。