Effects Of Propofol On Long-term Memory And Expression Of NMDAR2B And GABAR1 In The Brain Of Aged Rats

Background: Postoperative cognitive dysfunction(postoperative, cognitive dysfunction POCD) is a clinical syndrome that occurs in patients with mental disorder after surgery without preoperative psychiatric disorders. It is a common complication of surgery in elderly patients, the main clinical manifestations are personality changes, mental disorders, anxiety, and memory impairment. POCD can increase the postoperative mortality of elderly patients, and affect the quality of life of patients seriously after surgery. Research purposes: Exploratory laparotomy in aged rats under propofol anesthesia. To explore the effects of propofol and surgical stress on postoperative cognitive dysfunction, and to explore the effects of NMDAR2 B and GABAR1 expression in the hippocampus and lateral temporal lobe. Methods: Select 60 male healthy aged rats were randomly divided into control group(C), propofol group(P) and propofol operation group(PO), 20 rats in each group. Rats were used for five days Water Maze Test before surgery to make a stable memory of rats. Propofol group(PO) were established open exploratory operation model with anesthetized propofol after water maze test, the propofol group to give the same time of anesthesia. The water maze test was performed to test the learning and memory ability of each group after seven days operation. After two hours in the water maze test, routine paraffin embedding, immunofluorescence and FISH were performed to detect the expression of NMDAR2 B and GABAR1 in the lateral temporal lobe and hippocampus. Results: 1.Morris water maze results: PO group compared with the C group, the latency period was prolonged(P<0.05), and the frequency of the target platform was reduced(P<0.05). The latency time of the P group and the C group were not statistically significant.2.NMDAR2 B expression results: Compared with C group, the expression of NMDAR2 B in the hippocampus and lateral temporal lobe was significantly lower in the PO group(P<0.05) by Immunofluorescence and FISH detection. The expression of NMDAR2 B in group P and C group was not statistically significant.3.GABAR1 expression results: The expression of GABAR1 in hippocampus and lateral temporal lobe was significantly higher in group PO compared with C group(P<0.05), while the expression of GABAR1 in group P and C group was not statistically significant. Research conclusion: 1: Propofol anesthesia does not lead to long-term learning and memory damage in aged rats, and propofol combined with surgery affect the long-term learning and memory.2.Down-regulation of NMDAR2 B expression and up-regulation of GABAR1 expression involved in the effects of propofol operation on learning and memory in aged rats.3. Propofol and propofol operation not only caused the changes of related proteins in the hippocampus, but also had the same changes in the lateral temporal lobe. We hypothesized that postoperative cognitive dysfunction is common in many areas of the brain.