多次吸入七氟烷麻醉致老龄大鼠认知功能障碍时脑电波的变化

Changes in electroencephalogram during cognitive dysfunction induced by multiple inhalation of sevoflurane anesthesia in aged rats

目的评价多次吸入七氟烷麻醉致老龄大鼠认知功能障碍时脑电波的变化。方法SPF级健康雄性SD大鼠21只,20~22月龄,体重450~550 g。采用随机数字表法分为2组:对照组(C组,n=8)和多次吸入七氟烷麻醉组(S组,n=13)。S组大鼠置于麻醉箱中,通入3%七氟烷和30%氧气的混合气体,设置氧气流量3 L/min,维持3 h,每间隔1周吸入1次,共3次;C组仅吸入70%空气-30%氧气混合气体。2周后以Morris水迷宫实验测定大鼠认知功能,采用多通道生理信号系统采集并分析脑电图,脑电波信号记录时间30 min。处死大鼠取脑组织,采用TUNEL染色法计数凋亡神经细胞,计算神经细胞凋亡率。结果与C组比较,S组大鼠训练第3和4天时逃避潜伏期延长,第5天穿越原平台位置次数减少,高频波百分比降低,低频波百分比升高,神经细胞凋亡率升高(P<0.05)。结论多次吸入七氟烷麻醉致老龄大鼠认知功能障碍时高频波百分比降低,低频波百分比增加,可能与神经细胞凋亡有关。

Objective To evaluate the changes in electroencephalogram(EEG)during cognitive dysfunction induced by multiple inhalation of sevoflurane anesthesia in aged rats.Methods Twenty-one SPF healthy male Sprague-Dawley rats,aged 20-22 months,weighing 450-550 g,were divided into 2 groups using a random number table method:control group(group C,n=8)and repeated inhalation of sevoflurane anesthesia group(group S,n=13).In group S,the rats were put into an anesthesia box and inhaled a mixture of 3% sevoflurane and 30% oxygen for anesthesia,the oxygen flow rate was set at 3 L/min,maintaining for 3 h,and anesthesia was performed once every week for 3 times in total.The rats only inhaled a mixture of 70% air and 30% oxygen in group C.Two weeks later,cognitive function was assessed using Morris water maze test,the EEG was collected and analyzed by the multi-channel physiological signal system,and the recording time of EEG signal was 30 min.The rats were sacrificed,and the brains were collected for determination of the count of apoptotic nerve cells(by TUNEL staining),and the apoptotic rate of nerve cells was calculated.Results Compared with group C,the escape latency was significantly prolonged at 3rd and 4th days of training,the number of crossing the original platform was decreased at 5th day,the percentage of high-frequency waves was decreased,the percentage of low-frequency waves was increased,and the apoptosis rate of nerve cells was increased in group S(P<0.05).Conclusion The percentage of high-frequency waves is decreased,and the percentage of low-frequency waves is increased during cognitive dysfunction induced by multiple inhalation of sevoflurane anesthesia,which may be related to apoptosis in nerve cells of aged rats.