OBJECTIVETo observe the effect of huperzine A on the cognitive function of rats recovering from general anesthesia and discuss its possible mechanism.

METHODSSixty rats (20 to 23 weeks old) were subjected to spatial reference memory version of navigation task, in which the rats were expected to locate the escape platform in water. Two sessions of training were given daily for 5 days, and on the 5th day, the escape latencies of the rats were recorded. The rats were then divided randomly into 5 groups (n=12), and in 4 of the groups, the rats received an intraperitoneal injection of diprivan (Dip) at 2 mg/kg and after recovery of righting reflex, huperzine A was given at 0.05 mg/kg (group L), 0.1 mg/kg (group M), 0.2 mg/kg (group H), and in group C, no subsequent huperzine A was given; in group E, the rats received normal saline injection only. One hour after righting reflex recovery, the escape latencies of all the rats were recorded again, and the level of AChE expression in the forebrain cortex was measured quantitatively.

RESULTSThe escape latencies after righting reflex recovery was significantly longer than that on day 5 (P<0.05), and the rats in group H had the shortest escape latency among the groups (P<0.05). The average gray scale of AChE in the forebrain of rats in group H was significantly lower than that of the other groups (P<0.05).

CONCLUSIONHuperzine A can inhibit cholinesterase in the brain to improve the cognitive function of rats recovering from general anesthesia.