Objective: To study the effect of combined stress of noise and + Gz on learning and memory in rats.
Method: Thirty-two male SD rats were randomly divided into 4 groups: control group, +10 Gz/3 min group, 90 dB(A)/30 min noise group, combined stress group (+10 Gz/3 min and 90 dB(A)/30 min), 8 rats in each group. Changes of learning and memory after stresses were measured by means of Y-maze test, open field test and step-through test.
Result: As compared with control group and noise group, the number of correct reactions decreased significantly (P<0.01) and the reaction time increased significantly (P<0.01) in combined stress group at all time after stress; time stay in center grille (TSCG) increased significantly immediately after stress (P<0.01). When compared with control group, total time (TT) and number of error (NE) increased significantly (P<0.01) while latent time (LT) decreased significantly immediately and 6 d after stress (P<0.01). As compared with +10 Gz group, number of correct reactions in combined stress group decreased significantly (P<0.05) and reaction time increased significantly (P<0.01) immediately after stress.
Conclusion: It is suggested that combined stress of noise and +Gz may impair learning and memory of rats, and +Gz seems to contribute more to the combined effects.