Objective  To observe the effect of propofol on cognitive function and expression of hippocampal neuronal γ-aminobutyric acid (GABA) receptor in aged rats.

  Methods  Totally 50 elderly SD rats were randomly divided into propofol group and control group, with 25 rats in each group.Rats in the propofol group were injected with 6 mL/kg 1% propofol medium/long chain fat emulsion injection through abdominal cavity, while rats in the control group was injected with equal volume of normal saline through abdominal cavity.Morris water maze experiment was carried out at 1 day after anesthesia, the morphologic changes of hippocampal neurons and Nissl body were observed by HE staining and Nissl staining respectively, and the expression of GABA protein was determined by Western blot.

  Results  After anesthesia, there were no significant differences in anal temperature, heart rate, respiratory rate and blood oxygen saturation between the two groups (P>0.05).With the extension of the experimental time, the escape latency and the total mileage of rats in both groups decreased gradually, and the escape latency and the total mileage of the rats in the propofol group were significantly higher than those in the control group (P<0.05).The times and duration of rats crossing the platform area in the propofol group were significantly less and shorter than those in the control group (P<0.05).In the control group, Nissl bodies were found in the cytoplasm and dendrites, with deep staining and regular arrangement of nerve cells.In the propofol group, Nissl bodies disappeared, the number of nerve cells decreased, and the nucleus ruptured and lost.The expression of GABA protein in hippocampus of the propofol group was significantly lower than that of control group (P<0.05).

  Conclusion  Propofol has an effect on cognitive function in rats, which is related to the expression of GABA in hippocampus.