[Effects of high +Gx during simulated spaceship emergency return on learning and memory in rats].
OBJECTIVE
To observe the effects of high +Gx during simulated spaceship emergency return on learning and memory in rats.


METHODS
Thirty two male SD rats were randomly divided into control group, 7 d simulated weightlessness group, +15 Gx/180 s group and +15 Gx/180 s exposure after 7 d simulated weightlessness group, with 8 rats in each group. The changes of learning and memory in rats were measured after stresses by means of Y-maze test and step-through test.


RESULTS
In Y-maze test, as compared with control group, percentage of correct reactions decreased significantly (P<0.01) and reaction time increased significantly (P<0.01) in hypergravity after simulated weightlessness group at all time after stress; as compared with +15 Gx group or simulated weightlessness group, percentage of correct reactions decreased significantly (P< 0.05) and reaction time increased significantly (P< 0.05) immediately after stress. In step-through test, as compared with control group, total time increased significantly (P<0.01) in hypergravity after simulated weightlessness group at 1 d after stress; latent time decreased significantly (P<0.01) and number of errors increased significantly (P< 0.01) at all the time after stress. As compared with +15 Gx group, total time increased significantly (P<0.05) immediately, 1 d after stress. As compared with simulated weightlessness group, total time and number of errors increased significantly (P<0.05) immediately after stress.


CONCLUSIONS
It is suggested that +15 Gx/180 s and simulated weightlessness may affect the ability of learning and memory of rats. Simulated weightlessness for 7 d can aggravate the effect of +Gx on learning and memory ability in rats.
Xu
Zhi-peng
ZP
Sun
Xi-qing
XQ
Liu
Ting-song
TS
Wu
Bin
B
Zhang
Shu
S
Wu
Ping
P
D000818:Animals; D001522:Behavior, Animal; D018471:Hypergravity; D008297:Male; D018782:Maze Learning; D008568:Memory / Q000502:physiology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D011930:Reaction Time; D013997:Time Factors; D018474:Weightlessness Simulation