神经递质在睡醒转换中作用的数学模型仿真研究

根据已有的生理解剖知识［１ ］ 提出了关于入睡机制的三细胞环路模型及其网络模型［２ ］ 。在文献［２］ 模型的基础上，根据神经递质在睡醒转换中的重要作用及其作用方式主要是通过影响丘脑中的两种离子流－ 钾的漏电流（ＩＫＬ） 和超极化激活的阳离子流（Ｉｈ） ，以及丘脑皮质系统中突触传递强度的变化而起作用的生理知识，修改了［２］ 中三细胞环路模型及其网络模型。模型仿真结果显示，在适当调节模型参数的条件下，确能使细胞环路产生入睡纺锤节律与觉醒快速放电之间的双向转换，其网络模型也能通过同步振荡在皮层处出现人脑电中规定入睡标志的特征纺锤波与规定觉醒期的低幅快波之间的双向转换。此结果又一次启示了脑信息处理中如何通过同步振荡机制将表示微观特性的神经元群放电特征整合为脑的宏观功能状态的过程。

STUDY OF MODELING FOR MECHANISMS OF NEUROTRANSMITTERSYSTEMS IN THE TRANSITIONS BETWEEN FALLING ASLEEPAND AWAKE BRAINS

Based on physiological and anatomical knowledge, we have established models of three-cell circuit and networks for the mechanism of falling asleep. In this article, the models are modified from the model in according to the facts that neurotransmitters can influence the discharge patterns of neurones and the arousal and sleep states of brain through altering IKL, Ih, and the synaptic strengthes in the corticothalamic networks. The simulated results indicated that, when adjusting parameters in the model properly, the circuit model actually can transform between spindle rhythms and tonic firing patterns, generated during the states of falling asleep and awakening, respectively. Transitions between characteristic falling asleep spindles and awaked low-amplitude rapid waves, similar to those recorded in human EEG, are also obtained in CP from the network model through synchronization. These results enlighten us again the courses of information processing in which the microscopic electrical activities of neurones can be integrated into the macroscopic functional states of human brains through synchronous oscillation.