+6 Gz与噪声复合应激对大鼠学习记忆功能的影响

目的 :探讨中等强度正加速度和噪声复合应激对大鼠学习记忆功能的影响 .方法 :雄性SD大鼠 32只随机分为对照组、+6Gz 3min组、90dB(A) 30min噪声组、+6Gz 3min和 90dB(A) 30min噪声复合应激组 4组 ,每组 8只 .采用Y 型迷宫实验和避暗实验观察应激后不同时间大鼠学习记忆功能的变化 .结果 :+Gz组大鼠正确率在暴露后 2 ,4和 6d较对照组均显著下降 (P <0 .0 1) ,反应时均显著延长 (P <0 .0 1) .复合应激组大鼠正确率在暴露后各时间点较对照组和噪声组均显著降低 (P <0 .0 1) ,反应时均显著延长 (P <0 .0 1) ,而较 +Gz组则均无显著变化 ;总时间和错误数在暴露后即刻较对照组显著增加 (P <0 .0 1) ,潜伏期在暴露后即刻显著缩短 (P <0 .0 5 ) ,在暴露后 6d时仍显著缩短 (P <0 .0 5 ) .结论 :+6Gz 3min和 90dB(A) 30min噪声复合应激可引起大鼠持续性学习记忆功能障碍 .

Effects of +6 Gz and noise combined stress on learning and memory in rats

AIM: To study the effects of combined stress of noise and moderate +Gz on learning and memory in rats. METHODS: Thirty-two male SD rats were randomly divided into four groups with 8 rats in each group: control group, +6 Gz/3 min group, 90 dB(A)/30 min noise group, +6 Gz/3 min and 90 dB(A)/30 min noise combined stress group and the changes of learning and memory after stress were measured by Y-maze test and step-through test. RESULTS: As compared with that in control group, the percentage of right reaction decreased significantly (P<0.01) and the reaction time increased significantly (P<0.01) in +Gz group at 2 d, 4 d and 6 d after +Gz exposure. When compared with that in control and noise group, the percentage of right reaction decreased significantly (P<0.01) and the reaction time increased significantly (P<0.01) at all time points in combined stress group, but no significant changes were observed when compared with that in +Gz group. As compared with that in control group, the total time and number of error increased significantly (P<0.01) while latent time decreased significantly immediately and 6 days after stress (P<0.05) in combined stress group. CONCLUSION: It is suggested that combined stress of +6 Gz/30 min and 90 dB(A)/30 min noise may cause sustained impairment of learning and memory in rats.