脑皮层神经元动作电位的能量效率

项目名称： 脑皮层神经元动作电位的能量效率

项目编号： No.31271170

项目类型： 面上项目

立项/批准年度： 2013

项目学科： 生物科学

项目作者： 于玉国

作者单位： 复旦大学

项目金额： 88万元

中文摘要： 大脑以数瓦的能量消耗，每秒种却能执行一千兆次的运算操作来行使复杂的认知和计算功能。这种接近完美的高效节能的生物机制至今还是个迷。高效节能可能是生命遵循的一条规律。可能不仅约束优化了大脑神经网络布线结构模式，而且约束优化了单个神经元动作电位的产生机制。本课题研究目标：皮层神经元产生和传导动作电位的能量优化机制，及其对最佳神经信息编码的制约和影响。研究手段：结合计算神经科学方法、信息理论和神经电生理实验等手段进行综合交叉研究。研究内容：1）探讨神经元轴突的形态特征，钠钾钙等重要离子通道亚型的非均匀分布密度、动力学特性，对动作电位能量效率的影响；2）温度变化对动作电位产生过程能量效率的影响；3）能量效率对神经信息编码的约束优化。意义：有助于全面深入地揭示大脑皮层神经元电信号的能量机制。而高效节能的脑电信号能量机制将成为一个新的窗口来揭示大脑的工作原理，并会推动新型智能型节能生物仿生技术的发展。

中文关键词： 电缆能量方程；稀疏编码；神经网络；突触兴奋和抑制平衡；大脑尺寸增大

英文摘要： Consuming only about several watts energy, mammlian brains are able to carry out 1000 trillon times of operation per second. The biophysical mechanism of this extremely efficient energy expenditure is still not fully known. Conserving energy may be an essential rule to life. It is important not only as a limiting factor in optimizing brain wire connections but also constrains the mechanism in generating nervous electrical signals through which brain cells communicate: the action potentials (APs). Our aim here is to make a comprehensive study on the biophysical mechanisms by which cortical axons operate in the optimal energy efficient manner for action potential conduction along unmylinated axons and to investigate the functional consequences of this in facilitating efficient spike code in neural information processing. We plan to perform computational models, information theory and experimental recordings of mammalian brain cells to study: 1) how do physiological properties of unmyelinated axons and nonuniform distributions of Na+/K+/Ca2+ subunit channels contribute to efficient energy cost for an action potential? 2) how does temperature change affects action potential initiating dynamics and relevant energy consumption in cortical axons? 3) How is neural code efficiency constrained by metabolic efficiency? The

英文关键词： cable energy function；sparse coding；neural network；synaptic excitory and inhibitory balance；brain enlargement