钾离子浓度及离子通道电导对海马CA1区神经元自发放电的影响  

Effects of potassium concentration and ion channel conductance on spontaneous firing of Hippocampal

作　　者：解楠[1] 乔清理[1] 

机构地区：[1]天津医科大学生物医学工程学院,300070

出　　处：《国际生物医学工程杂志》2011年第2期86-90,共5页International Journal of Biomedical Engineering

基　　金：国家973计划项目（2005CB724302）;天津市自然科学基金资助项目（08JCYBJC03300）

摘　　要：目的 分析在胞外钾离子浓度【K＋]o和离子通道电导变化的情况下，海马CA1区单个神经元自发放电频率和放电模式的变化。方法对Warman等提出的模型进行改进，应用计算机软件MATLAB建立一个包括16个房室的海马CA1区锥体细胞单个神经元的电缆模型。其中树突室不含有源通道，而胞体室含有5个离子通道（Ina，INap、IDR、IA、IM），该模型不包括钙电流和由钙浓度调节的钾电流（ICa、ICT、IAHP）。结果仿真结果表明，海马CA1区神经元产生自发周期的放电行为；随着【K＋】o的增加，钠电导的增加和钾电导的减少，放电频率增加；单个神经元的自发放电行为以单峰或者每个簇内含有2个或3个峰的形式出现。结论神经元自发放电频率和放电模式的变化与[K＋]。以及离子通道电导等因素有关。Objective To analyse the variability of spontaneous firing frequencies and firing patterns of a Hippocampal CA1 neuron with the changes of extraeellular potassium concentration [K＋]o and ion channel conductance. Methods A 16-compartment cable model of a Hippoeampal CA1 neuron was developed based on the Warman model with computer software MATLAB. The dendrites contained no active channels, while five active channels （Ina,INap、IDR、IA、IM） -were contained in soma. In the model, the calcium currents and potassium currents （ICa, ICT and IAHP） regulated by calcium concentration were not included. Results Simulation results showed that the neuron could generate periodic spontaneous firing activity. The spiking frequency increased with the increasing of [K＋]o and sodium conductance and decreasing of potassium conductance. Spontaneous single neuron activity appeared in singlet or in grouped bursts of two or three spikes. Conclusion The variability of spontaneous firing frequencies and firing patterns of single neuron are relevant to [K＋]o and ion channel conductance.

关 键 词：海马CA1区 自发放电 放电频率 放电模式 

分 类 号：R[医药卫生]