Mechanisms of Inhibitory Glycine Receptor Modulation

K. Liu Lin Thio，医学博士，儿科癫痫学家，他对离子通道调制的研究事业感兴趣，因为它对理解和治疗癫痫等神经系统疾病很重要。他在细胞神经生理学方面有丰富的经验，但他想探索离子通道调节的分子机制。这就要求他学习分子生物学的基本技术，这也是本次提案的目标之一。包括癫痫在内的几种神经系统疾病可能部分由皮质抑制性甘氨酸受体（GlyR）功能障碍引起。因此，GlyR调节对于理解和治疗神经系统疾病非常重要。虽然已经确定了几种GlyR调节剂，但它们的作用机制尚不清楚，因为尚未进行定量药理学和电生理研究。本研究拟验证关于三种已知GlyR调节剂作用机制的三个假设：1)GlyR和γ -氨基丁酸（GABAA）受体通过细胞骨架相互作用；2)巯基还原剂通过螯合胞外锌抑制GlyR；3)巴比妥酸盐对GlyR电流的增强和抑制作用发生在不同的位点。这些假设将通过研究培养的胚胎小鼠海马神经元中天然GlyR的电生理特性以及爪蟾卵母细胞和人胚胎肾（HEK） 293细胞中表达的GlyR来验证。

K. Liu Lin Thio, MD, PhD is a pediatric epileptologist who is interested in developing a research career in ion channel modulation because of its importance to understanding and treating neurological diseases such as epilepsy. He has extensive experience with cellular neurophysiology but would like to probe the molecular mechanisms underlying ion channel modulation. This requires that he learn the basic techniques of molecular biology, which is one of the goals of this proposal. Several neurological disorders including epilepsy may result, in part, from cortical inhibitory glycine receptor (GlyR) dysfunction. Thus, GlyR modulation is important to understanding and treating neurological disease. Although several modulators of GlyR have been identified, their mechanisms of action are unknown because quantitative pharmacological and electrophysiological studies have not been performed. This study proposes to test three hypotheses regarding the mechanism by which three known GlyR modulators act: 1) GlyR and gamma-aminobutyric acidA (GABAA) receptors interact through the cytoskeleton; 2) Sulfhydryl reducing agents inhibit GlyR by chelating extracellular zinc; 3) Potentiation and inhibition of GlyR currents by barbiturates occur at distinct sites. These hypotheses will be tested by studying the electrophysiological properties of native GlyR in cultured embryonic mouse hippocampal neurons and GlyR expressed at Xenopus oocytes and human embryonic kidney (HEK) 293 cells.