| Objective:To investigate the effect of prenatal stress(PS)at different time on emotion and cognition of adult offspring.Methods:Sixteen healthy female Sprague Dawley(SD)rats were randomly divided into 4 groups,control group(CON,n=4);the early pregnancy group(PS1,the 1-7 days of pregnancy,n=4);the late pregnancy group(PS3,the 15-21 days of pregnancy,n=4)and the early plus late pregnancy group(PS1-3,the 1-7 days plus 15-21 days of pregnancy,n=4).The pregnant rats were exposed to single-prolonged stress(SPS)on gestational day 7,15 or 7-15 respectively,except control group.The offspring were measured every weekend from 1-8 week of birth.At 8w,the sucrose intake(anhedonia),forced swim test(FST),elevated plus maze(EPM)and Morris water maze(MWM)were performed to assess emotion and spatial learning and memory.SPSS21.0 was used to analyze data.Weight of rats(unit:g),sucrose preference rate(G,unit: %),T4,the number of entries the open arms and the time spend in the open arms in the elevated plus maze,the mean of average escape latency of rats in the first 5 days,the mean of rats across to platform quadrant in the sixth day in Morris Water Maze were recorded as meanąstandard deviation(sx ?).Significant level was P<0.05.The sucrose preference rate,the total stationary time of the last 4 minutes of rats in the forced swimming test(T4,unit: s),the number of entries the open arms and the time spend in the open arms in the elevated plus maze and the time and number of rats across to platform quadrant in the sixth day in Morris Water Maze variables were analyzed by one-way ANOVA,Bonferroni test was analyzed for group comparison.Repeated measures analysis was adopted for the mean of average escape latency of rats in the first 5 days in the MWM.1 In sucrose preference test,There was a significant effect of PS(F=52.597,P=0.000)and sex(F=5.931,P=0.018)on sucrose consumption.Post hoc analysis showed PS3 was reductive in sucrose consumption than con but PS1 inductive.The comparison among female offspring,PS3 females were reductive in sucrose consumption than control females(P<0.05)while PS1 inductive in sucrose consumption compared to the control group.The comparison among male offspring,PS3 males were reductive in sucrose consumption than control males(P<0.05)while PS1 males inductive in sucrose consumption compared to the control group(P<0.05).The comparison between female and male offspring,PS3 females reductive in sucrose consumption than PS3 males(P<0.01).There was no significant effect between PS1-3 and control.2 In the FST,there was a significant effect of PS(F=17.287,P=0.000)and sex(F=4.745,P=0.033)on time spent immobile.Post hoc analysis showed PS3 was spending more time immobile than control but PS1 and PS1-3spending less time.The comparison among female offspring,PS3 females were immobile for longer than control females while PS1 and PS1-3 shorter than control.The comparison among male offspring,PS3 males were immobile for longer than control males while PS1 and PS1-3 males were immobile for shorter than control(P<0.05).The comparison between female and male offspring,PS3 females were immobile for longer than PS3males(P<0.010).3 In the EMP,on the time spent in the open arms,there was a significant effect among PS(F=5.326,P=0.002),and sex(F= 11.638,P=0.001).Post hoc analysis showed that three PS groups spend less time in the open arms compared with the control.There was no significant effect among the three PS.PS3 females were spent less time in the open arms than PS3 males compared to control females.In the number of entries the open arms,there was a significant effect among PS(F=13.216,P=0.000),but sex(F=1.126,P=0.293)(F=2.757,P=0.049)was no significant effect.PS1 and PS3 groups were less in the number of entries the open arms compared with the control(P<0.01).4 Investigating the effect of SPS on the spatial learning in PS1,PS3 and PS1-3 using repeated measures,showed a significant effect of PS on escape latency(F=10.653 P=0.000).Moreover,during the training course,the effect of time was significant(F=82.068,P=0.000),but showed not a significant main effect of sex.On the first day,PS3 and PS1-3 are induced a slight decrease while PS1 a slight increase in the escape latency,but not significant.The escape of latency of the male and female offspring,whose dams had been explored PS,was decreased,but not significant(F=1.963,P>0.05).On the2-5days in EL,there was significant among the four gropes(F:5.057,4.463,11.052,10.245,P<0.05).On the second day,a significant effect of PS3 and PS1-3 were observed,compared to control.The escape latency of the PS3 and PS1-3 was decreased significantly.On the third day,the PS1 was significantly increased while PS1-3 was significantly decreased.On the fourth and last day,PS1 was significantly increased compared with control(P<0.01).On the sixth day after learning acquisition,rats were allowed to probe test in MWM.The ANOVA for the duration in platform location showed a significant main effect of stress(F=6.801,P=0.000)and numbers of times across the platform showed a significant main effect of stress(F=9.014,P=0.000),but showed not a significant main effect of sex.In duration in platform location and in number of times across the platform,Bonferroni post hoc test indicated an increased in PS3 compared to control(P<0.05).Conclusions:Different prenatal stress had different effect on the emotion and cognition of adult offspring rats1 PS1 offspring decreased depression-like behavior,increased anxietylike behavior and impaired spatial learning.The gender-specificity of PS effects on the emotion and cognition showed no significant difference.2 PS3 offspring increased depression-like behavior and anxiety-like behavior but enhanced spatial learning and memory.Females are more depressed and anxious.The gender-specificity of PS effects on cognition showed no significant difference.3 PS1-3 offspring had no significant effects on the emotion andcognition.4 Between the sexes,only PS3 female offspring are more depressed and anxious. |
PDF Full Text Request