神经元超兴奋与随机共振

The present study explored mainly on the mechanisms of neuronal hyperexcitability and it's relationship with stochastic resonance. It's an advanced research involving the intercross of neuroscience and nonlinear science. Two main progresses have been obtained via the ways of both electrophysiological experiment on neurons and theoretical analysis on mathematical neuron model. First, a subthreshold membrane potential oscillation has been found in the injured sensory neurons and been regarded as the basic linkage determining the production of spontaneous discharge and the firing pattern. Thus we suggest that the subthreshold membrane potential oscillation is a primary index of neuron hyperexcitability which may contribute to further elucidating of the membrane mechanism of hyperexcitability. Second, for some parameters the forced FitzHugh-Nagumo neuron model has two attractors: the subthreshold and superthreshold periodic oscillations. Random transitions between these two periodic oscillations are the essential mechanism underlying stochastic resonance in this model. These results break a new way to the study of the mechanism of stochastic resonance and may have important theoretical significance and practical advancement.The above progress contribute much to the obtaining of the support of National Natural Science key grant and make benefits to the study of nonlinear characteristics of neurons as well as the neuronal coding.

在新建的神经元超兴奋标本，分析自发放电间期整数倍形式与随机共振的关系，测量不同放电形式反应敏感性，判定内部噪声及Na通道介导阈电位在随机共振的作用；利用神经元数学模型验证神经元随机共振发生条件和动力学过程，以确定神经元超兴奋的超敏反应阶段，阐明其随机共振机制，为揭示神经元超兴奋本质，论证神经信息编码新方式提供重要依据。