Effect of low-dose ketamine on efficacy of electroconvulsive therapy under propofol anesthesia in depressed rats

Abstract

Objective To evaluate the effect of low-dose ketamine on the efficacy of electroconvulsive therapy (ECT) under propofol anesthesia in depressed rats. Methods Sixty adult male SD rats weighing 200-250 g were used in this study. The depression model was established by chronic unpredictable mild stress (CUMS). The animals were then randomly divided into 6 groups (n = 10 each): control group (group C), depression group (group D), propofol group ( group P), propofol + ECT group ( group PE), ketamine + propofol group ( group KP), and ketamine + propofol + ECT group (group KPE). Groups P and KP received intraperitoneal propofol 100 mg/kg and ketamine 10 mg/kg + propofol 80 mg/kg respectively, and groups PE and KPE received ECT after intraperitoneal injection of propofol 100 mg/kg and ketamine 10 mg/kg + propofol 80 mg/kg respectively once a day for 7 consecutive days. All rats underwent sucrose fluid consumption and Morris water maze tests before CUMS, after CUMS, and after treatment. Results Compared with group C, the sucrose consumption percentage was significantly decreased, the escape latency was prolonged, and the time spent in the target quadrant (the original platform quadrant) was shortened after CUMS in D, P, PE, KP and KE groups ( P ＜ 0.05). Compared with group D,the sucrose consumption percentage was significantly increased (P ＜ 0.05), while no significant change in the escape latency and time spent in the target quadrant was found after treatment in group KPE ( P ＞ 0.05 ), and the sucrose consumption percentage was significantly increased, the escape latency was prolonged, and the time spent in the target quadrant was shortened after treatment in group PE ( P ＜ 0.05). Compared with group PE, the sucrose consumption percentage was significantly increased, the escape latency was shortened, and the time spent in the target quadrant was prolonged after treatment in group KPE ( P ＜ 0.05). Conclusion Low-dose ketamine can not only enhance the efficacy of ECT under propofol anesthesia in depressed rats, but also reduce cognitive impairment induced by ECT. Key words: Ketamine; Propofol; Depressive disorder; Electroconvulsive therapy