Cape E G, Jones B E
Department of Neurology and Neurosurgery, McGill University, Montréal Neurological Institute, Montréal, Québec H3A 2B4, Canada.
J Neurosci. 1998 Apr 1;18(7):2653-66. doi: 10.1523/JNEUROSCI.18-07-02653.1998.
Several lines of evidence indicate that cholinergic basalis neurons play an important role in cortical activation. The present study was undertaken to determine the effect of noradrenergic and serotonergic modulation of the cholinergic neurons on cortical EEG activity and sleep-wake states. The neurotransmitters were injected into the region of the basalis neurons by remote control in freely moving, naturally sleeping-waking rats during the day when the rats are normally asleep the majority of the time. Effects were observed on behavior and EEG activity, including high-frequency gamma activity (30-60 Hz), which has been demonstrated to reflect behavioral and cortical arousal in the rat. Noradrenaline, which has been shown in previous in vitro studies to depolarize and excite the cholinergic cells, produced a dose-dependent increase in gamma-EEG activity, a decrease in delta activity, and an increase in waking. Serotonin, which has been found in previous in vitro studies to hyperpolarize the cholinergic neurons, produced a dose-dependent decrease in gamma-EEG activity with no significant change in amounts of wake or slow wave sleep. Both chemicals resulted in a dose-dependent decrease in paradoxical sleep. These results demonstrate that noradrenaline and serotonin exert differential modulatory effects on EEG activity through the basal forebrain, the one facilitating gamma activity and eliciting waking and the other diminishing gamma activity and not significantly affecting slow wave sleep. The results also confirm that the cholinergic basalis neurons play an important role in cortical activation and particularly in the high-frequency gamma activity that underlies cortical and behavioral arousal of the wake state.
多条证据表明，基底核胆碱能神经元在皮层激活中发挥重要作用。本研究旨在确定去甲肾上腺素能和5-羟色胺能对胆碱能神经元的调节作用对皮层脑电图活动和睡眠-觉醒状态的影响。在白天自由活动、自然睡眠-觉醒的大鼠中，当大鼠大部分时间处于正常睡眠状态时，通过遥控将神经递质注入基底核神经元区域。观察对行为和脑电图活动的影响，包括高频γ活动（30 - 60赫兹），已证明该活动可反映大鼠的行为和皮层觉醒。在先前的体外研究中已表明去甲肾上腺素可使胆碱能细胞去极化并兴奋，它可使γ脑电图活动呈剂量依赖性增加，δ活动减少，觉醒增加。5-羟色胺在先前的体外研究中已发现可使胆碱能神经元超极化，它可使γ脑电图活动呈剂量依赖性减少，而觉醒或慢波睡眠量无显著变化。两种化学物质均导致异相睡眠呈剂量依赖性减少。这些结果表明，去甲肾上腺素和5-羟色胺通过基底前脑对脑电图活动发挥不同的调节作用，一种促进γ活动并引发觉醒，另一种减少γ活动且对慢波睡眠无显著影响。结果还证实，基底核胆碱能神经元在皮层激活中，特别是在构成觉醒状态皮层和行为觉醒基础的高频γ活动中发挥重要作用。
