The Study Of Maternal Separation Stress On Learning And Memory And NMDA Receptor Subunits NR₁ Expression In The Hippocampus Of Immature Rats

Objective : To study the effects of maternal separation stress on learning and memory and the hormone levels and NMDA receptor subunits NR1 expression in hippocampus of immature rats.Methods : The rats were randomly divided into stress group(Three hours daily maternal separation on postnatal day 2～21) and control group(no handing on postnatal day 2～21).The Morris water maze was used to observe the learning and memory abilities of the rats, euzymelinked immunosorbent assay was used to test the level of norepinephrine,5-hydroxytryptamine and corticosterone in blood serum,Immunohistochemistry to detect the expression changes of NR1 of the hippocampus. Results :The learning and memory abilities of the control group much better than the stress group(P<0.05);The stress group also resulted in significantly higher blood serum noradrenaline, corticosterone(P<0.05), but the level of 5-hydroxytryptamine was the same in both groups(P>0.05); The expression of NR1 was significantly increased in the stress group (P<0.05).Conclusion : Maternal separation was damaged the learning and memory abilities of the immature rats in the early mental stress ;One of these mechanisms might be related with the changes of hormone levels changes and the expression changes of NMDA receptors.