Effects of low gravity preconditioning on rat learning and memory impairment induced by high gravity exposure

Abstract

Abstract: Objective To study the protective effects of low gravity preconditioning against learning and memory function impairment induced by high gravity exposure in rats. Method Twenty-four male SD rats were randomized equally into control group, high gravity exposure group(+10 Gz/3 min) and low gravity preconditioning group(LGP group, preconditioned by a daily exposure to +4 Gz/3 min for 3 days before +10 Gz/3 min exposure). Both the learning and memory abilities of the rats in the 3 groups were examined after +10 Gz/3 min exposure. Results In open field test, the rats exposed to +10 Gz/3 min, in comparison with the control rats, exhibited significantly declined total square-crossing and rearing(SCR) on days 0 and 2(P<0.05), with also significantly prolonged stay in the central square at 0 d(P<0.01). In the low gravity preconditioned rats, SCR declined and length of stay in the central square increased significantly on day 0(P<0.01). Compared with the rats in +10 Gz/3 min group, the rats in the LGP group showed decreased length of stay in the central square on day 2, and such changes was statistically significant on day 6(P<0.05), but there was no difference in SCR at all time points. In Y-maze test, the number of times of right reaction(RR) decreased and the reaction time(RT) increased significantly in +10 Gz/3min group compared with those of the control group(P<0.01), whereas no significant differences were found between the control group and LGP group. Compared with +10 Gz/3 min group, the RR was increased(P<0.01) and RT shortened significantly(P<0.01) in LGP group. In the step-through test, the latent time(LT) increased(P<0.05) on day 0 but was then shortened significantly on day 6 in + 10 Gz/3min group(P<0.01), and no difference was found between LGP group and the control group. LT on day 6 increased significantly(P<0.01) in LGP group as compared with the +10 Gz/3 min group. Conclusion High gravity exposure-induced rat learning and memory impairment can be markedly improved by lower gravity preconditioning.

CLC Number:

R852.21

CAO Xin-sheng, WU Xing-yu, SUN Xi-qing, LIU Ting-song. Effects of low gravity preconditioning on rat learning and memory impairment induced by high gravity exposure[J]. Journal of Southern Medical University, 2005, 25(02): 212-215.

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