T-Channel Dysregulation during Alcohol Withdrawal: Mechanisms and Novel Therapies

描述（由申请人提供）：本研究培训计划的主要目标是确定酒精戒断期间T型钙通道（T通道）失调的分子机制，并确定T通道是否可以作为酒精戒断发作的临床前治疗靶点。包括癫痫发作在内的戒断症状会使个体复发，从而成为康复的重大障碍。随着每一次连续的戒断，症状的严重程度增加，类似于一种引火现象。由于酒精对中枢神经系统的抑制作用，进行性神经元兴奋的代偿机制随之产生，同时伴有脑节律紊乱。使用间歇性酒精暴露范例，我们的实验室已经确定了戒断期间丘脑t型钙异构体CaV3.2的破坏，这可能是戒断发作的产生和传播的基础。导致t通道兴奋性异常增加的机制尚不清楚，以及针对t通道的药物治疗是否有效。我建议在多个层面解决这一潜在机制。特异性目的1将评估使用非特异性t通道拮抗剂乙氧亚胺和抗坏血酸（一种特异性CaV3.2 t通道拮抗剂）作为治疗酒精戒断期间癫痫发作活动的方法。为了进一步揭示酒精戒断期间t通道失调的机制，Aims 2和3将评估翻译后修饰是否通过蛋白激酶C （PKC）介导观察到的兴奋性增加，以及神经元限制性沉默因子（NRSF）在转录调控中的作用

DESCRIPTION (provided by applicant): The primary objectives of this research training plan is to identify the molecular mechanisms responsible for T- type calcium channel (T-channel) dysregulation during alcohol withdrawal, and to determine whether T- channels can serve as preclinical therapeutic targets for alcohol withdrawal seizures. Withdrawal symptoms including seizures drive individuals to relapse, thus representing a significant barrier to recovery. With each successive withdrawal, symptoms increase in severity in a kindling-like phenomenon. Due to the depressing effects of alcohol in the CNS, compensatory mechanisms of progressive neuronal excitation ensue, with concurrent development of disrupted brain rhythms. Using an intermittent alcohol exposure paradigm, our lab has identified a disruption in the thalamic T-type calcium isoform, CaV3.2, during withdrawal that may underlie the generation and propagation of withdrawal seizures. The mechanisms responsible for the abnormal increases in excitability of T-channels are unknown, as well as whether or not pharmacological treatments targeting T-channels may be effective. I propose to address this potential mechanism at multiple levels. Specific Aim 1 will evaluate the use of ethosuximide, a non-specific T-channel antagonist, and the use of ascorbate, a specific CaV3.2 T-channel antagonist, as treatments against seizure acitivity during alcohol withdrawal. To further reveal mechanisms responsible for T-channel dysregulation during alcohol withdrawal, Aims 2 and 3 will evaluate if posttranslational modifications mediate the observed increase in excitability via protein kinase C (PKC) and the role of neuron-restrictive silencer factor (NRSF) in transcriptional regulation of CaV3.2 T-channel. This training plan proposed involves a multidisciplinary approach that will serve to advance the alcohol field by providing a better understanding of mechanisms and identifying novel targets for therapeutic intervention for individuals suffering from alcohol abus. This research approach will provide training in both electrophysiology and molecular techniques including surgical procedures, EEG analysis, patch clamp electrophysiology, quantitative reverse transcription polymerase chain reaction (qRT-PCR), and Western blot techniques. With guidance and support from the advisor and research associates, this project will provide the necessary training to pursue questions that will provide insight into the serious conditions that develop after chronic alcohol abuse.