Sodium and Calcium Channels: Structure, Function, Neuroplasticity, and Disease

电压门控钠(Nav)和钙(Cav)通道产生动作电位并启动突触 在神经元中的传递。它们的突变会导致遗传性癫痫、偏头痛、慢性疼痛和周期性 麻痹，它们是药物的重要分子靶点。A.对导航系统结构和功能的新见解 通道来自我们对它们的细菌祖先Navab的高分辨率X射线结晶学。我们会 进一步定义哺乳动物NAV通道关键功能特性的结构基础 进入Navab的特征结构特征，包括电压依赖激活的结构基础，离子 选择性和快速失活。根据这些结果，我们将确定NAV受损的结构基础 引起周期性瘫痪和慢性疼痛综合征红斑性肢痛症的突变所致的经络功能 以及阵发性极度疼痛障碍。B.学习和记忆的失败是衰老和衰老的一个衰弱方面 神经退行性疾病，但我们并不了解这些关键大脑过程的基本机制 我们无法有效地干预这些赤字。学习和记忆主要发生在突触上。 突触前钙(Cav2.1)通道在大脑中的大多数突触启动神经递质的释放。这个 这些通道的活性受到大量信号蛋白复合体的严格调控，包括钙调蛋白和 相关的钙敏感蛋白。我们的工作表明Cav2.1通道调节与突触的短期可塑性有关 在培养神经元的转基因突触中，以及在IM-AA突变为 插入到Cav2.1中。我们将进一步确定Cav2.1通道的分子和结构机制 调节，确定Cav2.1通道调节在神经突触短期可塑性中的作用 环路，并探讨Cav2.1通道的调节在空间突触可塑性中的作用 学习和记忆。我们用这种独特的老鼠模型进行的实验将给我们提供独特的见解 海马神经元短时突触前可塑性的机制及其在整合脑中的作用 功能。德拉韦综合征(DS)是一种毁灭性的儿童神经精神障碍，由从头开始引起， Nav1.1中的杂合性功能丧失突变。我们开发了一种具有所有特征的小鼠遗传模型 DS包括热性和自发性癫痫、共济失调、昼夜节律和睡眠障碍， 认知缺陷，自闭症样特征，以及通过SUDEP过早死亡。生理学和遗传学研究 结果表明，这些效应与钠电流的丧失和GABA能中间神经元的兴奋性有关。 对兴奋性神经元没有一致的作用，从而导致神经兴奋与抑制的失衡 电路。为了进一步加深对DS的病理生理学和治疗的了解，我们将确定 负责DS的神经细胞和电路使用Cre-Lox方法的特定缺失，识别 在体内首次出现在DS小鼠体内的神经细胞和神经回路的超兴奋性，并优化下一代 DS患者癫痫发作、癫痫持续状态、认知障碍和过早死亡的综合治疗。

Voltage-gated sodium (Nav) and calcium (Cav) channels generate action potentials and initiate synaptic transmission in neurons. Mutations in them cause inherited epilepsy, migraine, chronic pain, and periodic paralysis, and they are important molecular targets for drugs. A. New insights into structure and function of Nav channels have come from our high-resolution x-ray crystallography of their bacterial ancestor NavAb. We will further define the structural basis for key functional properties of mammalian Nav channels by building their characteristic structural features into NavAb, including the structural basis for voltage-dependent activation, ion selectivity, and fast inactivation. Based on these results, we will determine the structural basis for impaired Nav channel function by mutations that cause periodic paralysis and the chronic pain syndromes erythromelalgia and paroxysmal extreme pain disorder. B. Failure of learning and memory is a debilitating aspect of aging and neurodegenerative disease, yet we do not understand the basic mechanisms of these crucial brain processes and we cannot intervene effectively in these deficits. Learning and memory takes place primarily at synapses. Presynaptic calcium (Cav2.1) channels initiate neurotransmitter release at most synapses in the brain. The activity of these channels is tightly regulated by a large complex of signaling proteins, including calmodulin and related calcium-sensor proteins. Our work implicates Cav2.1 channel regulation in short-term synaptic plasticity in transfected synapses in cultured neurons and in a novel mouse model in which the IM-AA mutation is inserted into Cav2.1. We will further define the molecular and structural mechanism for Cav2.1 channel regulation, determine the role of regulation of Cav2.1 channels in short-term synaptic plasticity of neural circuits, and explore the role of regulation of Cav2.1 channels and short-term synaptic plasticity in spatial learning and memory. Our experiments with this unique mouse model will give unique insights into the mechanism of short-term presynaptic plasticity in hippocampal neurons and its role in integrative bbrain function. C. Dravet Syndrome (DS) is a devastating childhood neuropsychiatric disorder caused by de novo, heterozygous loss-of-function mutations in Nav1.1. We developed a mouse genetic model with all the features of DS, including thermally induced and spontaneous seizures, ataxia, circadian rhythm and sleep disorders, cognitive deficit, autistic-like features, and premature death via SUDEP. Physiological and genetic studies show that all these effects are correlated with loss of Na currents and excitability of GABAergic interneurons, without consistent effects on excitatory neurons, which causes imbalance of excitation vs. inhibition in neural circuits. To further advance understanding of pathophysiology and treatment of DS, we will determine the neural cells and circuits responsible for DS using specific deletion by the Cre-Lox method, identify the sites of hyperexcitability in neural cells and circuits that appear first in DS mice in vivo, and optimize next-generation combination therapy for seizures, status epilepticus, cognitive deficit, and premature death in DS.