丙泊酚对小鼠外侧下丘脑促觉醒脑区的作用及觉醒和意识水平的影响

Effect of Propofol on Arousal Promoting Brain Area and Arousal and Consciousness Level in Lateral Hypothalamus of Mice

目的:研究丙泊酚对外侧下丘脑促觉醒脑区的作用机制。方法: 20只G57小鼠均分为对照组和丙泊酚组,两组小鼠于颅骨表面埋管(顶叶和额叶)记录脑电图(EEG)、同时将另一记录电极置颈部肌肉记录肌电图(EMG);在下丘脑外侧核坐标的颅骨表面置微量注射导管,对照组或丙泊酚组小鼠分别注射生理盐水或丙泊酚0.3μL;记录小鼠注射前后EEG及EMG特征,分析EEG与EMG的对应关系及丙泊酚对EEG特征的影响。结果:与对照组相比,丙泊酚组小鼠觉醒时间显著减少( P <0.001),非快眼动睡眠(NREM)和快眼动睡眠(REM)时间明显增加( P <0.001);通过对EEG的能量谱分析发现,外侧下丘脑给予丙泊酚后可引起EEG的低频δ振荡增强( P <0.001),与警觉程度密切相关的θ振荡减弱( P <0.001)。结论:丙泊酚可作用于外侧下丘脑,引起动物觉醒和警觉程度下降。

Objective: To investigate the Mechanism of propofol on promoting arousal brain area in lateral Hypothalamus. Methods: 20 G57 mice were divided into control group and propofol group.Electroencephalogram (EEG) was recorded in two groups of mice on the surface of the skull (parietal lobe and frontal lobe),and another recording electrode was put into neck muscle to record electromyography (EMG).Microinjection catheter was installed on the surface of the skull at the coordinates of the lateral nucleus of the Hypothalamus,and mice in control group or propofol group were injected with saline or propofol 0.3 μL,respectively.The characteristics of EEG and EMG,the corresponding relationship between EEG and EMG were recorded before and after injection,and the effect of propofol on the characteristics of EEG was analyzed. Results: Compared with the control group,the awakening time of mice in propofol group was significantly decreased( P< 0.001).Non-fast eye movement sleep (NREM) and fast eye movement sleep (REM) time were significantly increased( P< 0.001).Through the analysis of energy spectrum of EEG,it was found that propofol administration to lateral hypothalamus could enhance the low frequencyδ oscillations of EEG( P< 0.001),and the theta oscillations,which were closely related to the degree of alertness,weaken the low frequencyθoscillations of EEG( P< 0.001). Conclusion: Propofol can act on the lateral Hypothalamus,causing the decrease of arousal and alertness in animals.