Experimental and Modeling Study on the Stabilization Mechanism of Neuronal Network by Aminergic System

将自制的不锈钢微电极微透析探针插入猫外侧膝状体核，在10 μ M 5-羟色胺灌注的睡眠-觉醒状态下，连续记录单个神经元活动数小时以上<-2>。结果表明：（1）对照组慢波睡眠时，神经元放电呈爆发性和沉默性，平均放电率低，呈白色噪声样动力学特征;而5-羟色胺灌注时，神经元放电呈紧张性和高放电率，且呈1/* 波动。(2)在快速眼动睡眠期间，由于5-羟色胺灌注，放电率呈紧张性增加。对照组和药物供应组均持续观察到1/* 波动。(3)在5-羟色胺灌注期间观察到紧张性膜去极化。毕竟，迄今为止，在中枢神经系统的单个神经元活动中观察到1/* 波动的是以下三种状态：（1）REM睡眠（2）大脑5-羟色胺耗尽的状态。(3)另一方面，在慢波睡眠期间和动物高度关注环境的唤醒状态期间都观察到了类似白色噪声的动态。因此，血清素、去甲肾上腺素、乙酰胆碱等神经调节物质的失衡会使我们称为“执行系统”的中枢神经子系统的神经元活动产生1/* 波动。

We fabricated a probe of microdialysis with stainless steel microelectrodes which was inserted into the lateral geniculate nucleus of a cat. A single neuronal activity was recorded for more than several hours stably during sleep-waking states, during which 10^<-2>M serotonin was perfused. Following results were obtained :(1) During slow wave sleep of control state, the neuronal activity was characterized by a burst and silence type of firing with a low mean discharge rate, and had white noise like dynamics, whereas it showed a tonic and higher firing rate with 1/* fluctuations for serotonin perfusion.(2) During REM sleep the firing rate was tonically increased due to serotonin perfusion. The 1/* fluctuations were constantly observed for both control and drug supply.(3) The tonic membrane depolarization was observed during serotonin perfusion.After all, so far, it is the following three states when 1/* fluctuations have been observed in a single neuronal activity of the central nervous system :(1) REM sleep(2) the state in which the brain serotonin is depleted.(3) slow wave sleep during which serotonin of high concentration was diffused through a microdialysis probeOn the other hand, the white noise like dynamics has been observed both during slow wave sleep and during arousal state in which an animal is highly attended to the environment. Therefore, imbalance of neuromodulatory substances such as serotonin, noradrenaline, acetylcholine, etc.would produce 1/* fluctuations in a neuronal activity of the central nervous subsystem we call "executive system".