Effect of single prolonged stress in different pregnant time on the emotion and cognitive function of adult offspring rats / 中华行为医学与脑科学杂志

ABSTRACT

Objective To investigate the effect of prenatal stress (PS) at different pregnant time on emotion and cognition of adult offspring rats.Methods Twelve healthy female Sprague Dawley (SD) rats were randomly divided into control group(CON,n=4),the early pregnancy group(PS1,the 1～ 7 days of pregnancy,n=4) and the late pregnancy group(PS3,the 15 ～ 21 days of pregnancy,n=4).The pregnant rats were exposed to single-prolonged stress(SPS) on gestational day 7 or 15 respectively,except control group.The offspring were measured every weekend from 1-7 week after birth.At the eighth weekend,the sucrose intake (anhedonia) and Morris water maze (MWM) were performed to assess depression-like behavior and spatial learning and memory.Results The body weight of the first to seventh weeks after birth showed that there was a statistically significant difference among the three groups (F=28.207,P＜0.01),and there was a significant difference in time effect (F=1 041.546,P＜0.01).The body weight of two PS groups was significantly lower than those of control group(P＜0.05).The body weight of PS3 was lower than that of PS1 significantly(P＜0.05).Sucrose preferencePS3((27.70± 19.31) ％) were reductive on sucrose consumption than CON significantly((66.93±19.67) ％)(P＜0.05)while PS1 ((89.80±6.79) ％) increased in sucrose consumption compared with the CON significantly(P＜0.05).MWMin training stage the difference of average avoid latency was existed in the three groups of the first 5 days(F=11.121,P＜0.01).Similarly,there was a significant difference in measure time(F=91.327,P＜0.01),the escape latency of the PS3 was decreased,while PS1 was significantly increased compared with CON;in testing stage,PS3 ((54.50±4.64) s,(53.21±4.45)) showed a significant increase in the duration in target site and numbers of times across the target site compared with CON((32.24±.4.17) s,(31.68±4.00)) (P＜0.05).Conclusion The acceptance of stress in the late pregnancy may lead to depression like behavior in the adult offspring and also enhance the learning and memory ability.And acceptance of stress in early pregnancy can cause impairment of learning and memory ability in adult offspring rats.