Changes in electroencephalogram during cognitive dysfunction induced by multiple inhalation of sevoflurane anesthesia in aged rats / 中华麻醉学杂志

ABSTRACT

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.