Molecular mechanisms underlying inactivation of voltage-

电压失活的分子机制

• 批准号: 6990003
• 负责人: JOHN CLAY
• 金额: --
• 依托单位: NATIONAL INSTITUTE OF NEUROLOGICAL DISORDERS AND STROKE
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/6990003
• 关键词: Xenopus oocyte; acidity /alkalinity; biological signal transduction; calcium channel; ion transport; membrane activity; membrane potentials; neuronal transport; organelles; potassium channel; site directed mutagenesis; slow potential; sodium channel; voltage gated channel

This laboratory has made use of a novel finding concerning the effects of intracellular pH on membrane excitability in squid giant axons. Under certain conditions these preparations either fire action potentials in a rhythmic, spontaneous manner, or they are quiescent, i.e., they are bistable. We have injected computer generated noise in these axons to investigate the transitions between the two stable states. Membrane noise is a ubiquitous feature of neurons in the central nervous system, especially neurons in the brain. Bistability has been hypothesized to occur in neurons in areas of the brain undergoing epiliptic seizures. Brief duration current pulses applied at a critical point in the spontaneous firing cycle of one of these cells can terminate the activity, that is, it can reset the neuron to its stable rest state. Membrane noise may be a more efficacious way of accomplishing this result, since a small amplitude noise signal is sufficient, and the timing of the noise pulse is not as critical as in the case of a current pulse. These results might have relevance in the design of implantable devices in the brain as one way of controlling seizure activity.

该实验室利用了一个新的发现，细胞内pH值对鱿鱼巨轴突膜兴奋性的影响。在某些条件下，这些制剂要么以有节奏的自发方式激发动作电位，要么它们是静止的，即，他们是……我们在这些轴突中注入了计算机生成的噪声，以研究两种稳定状态之间的转换。膜噪声是中枢神经系统中神经元的普遍特征，尤其是大脑中的神经元。双稳态被假设发生在癫痫发作的大脑区域的神经元中。在这些细胞之一的自发放电周期的临界点施加短暂持续时间的电流脉冲可以终止活动，也就是说，它可以将神经元重置到其稳定的静息状态。膜噪声可以是实现该结果的更有效的方式，因为小幅度噪声信号是足够的，并且噪声脉冲的定时不像电流脉冲的情况那样关键。这些结果可能与大脑中可植入设备的设计有关，作为控制癫痫发作活动的一种方式。