Effect of intracerebroventricular injection of orexinA on recovery of rats receiving anesthesia

【Objective】To determine the effect of intracerebroventricular (icv) injection of orexinA on the recov ery of rats receiving general anesthesia. 【Methods】After intraperitoneal injection of ketamine (75 mg/kg) and mida zolam (5 mg/kg), different doses of orexinA were administered intracerebroventricularly (icv) to rats. The duration o loss-of-righting reflex (LRR) were used to evaluate the recovery time,the duration of post-LRR ataxia were used t evaluate the motor function. 4 hours after anesthesia, the learning and memory function were studied by Morris Water Maze test. 【Results】Compared with the control group, high dose of orexinA (4 nmol) induced significant de crease in the duration of LRR and post-LRR ataxia (P 0.01). In Morris Water Maze test, high dose of orexinA de creased the escape latency (P 0.01) and increased the duration that spent in the target quadrant significantly (P 0.05). However, there was no significant change in these parameter in low dose orexinA group with respect to th control group.【Conclusion】 The icv injection of orexinA in rats shortens the recovery from anesthesia and improve motor function and cognitive performance.