The Study Of ER And Neural Plasticity In Female Mice Brain After Chronic Restraint Stress

Depression belongs to a mental disorder. Its typical character is low spirits.Stress is an unspecific adaptive response when people or animals are confronted withvarious stimuluses. Social stress, such as the quickened social rhythm, increasinglyfuried work competition, makes people bear more and more mental burdens. Stressfullife events are associated with depression, suggesting that the social stress could be animportant factor in the pathogenesis of some depressive disorders. There are sexdifferences in vulnerability for affective disorders, such that prevalence rates fordepression among women are approximately double that seen in men. One factor thatmay underlie women's increased vulnerability to affective disorders may be estrogen (E).Estrogen replacement therapy (ERT) can be an effective treatment for mood disorders,such as premenstrual dysphoric disorder, postpartum depression and perimenopausaldepression. However, the effects of E and ER in stress-induced depression are notunderstood yet.Kalirin is necessary for maintenance of dendritic spines and dendritic branches.Previous research revealed that the atrophy of dendrities could be induced by chronicstress or ovariectomy, but that whether Kalirin is involved in the pathology ofstress-induced depression through influencing the changes of dendrities is not knownuntil recently.In order to solve these problems, we selected female mice, adopt chronic restraintstress to construct animal depression model and forced swimming test (FST) to test theirbehaviors. We also use immunohistochemistry to observe the expression of ER_α, ER_βand kalirin in hippocampus and amygdala. The purpose of this research is to study theeffects of E, ER and kalirin in stress-induced depression and provide some referencesfor the therapy of affective disorders. The results are as follows:(1)Chronic restraint stress could notably restrain the augment of animals weight andincrease their immobility time in FST. Compared with control group, there weresignificant reduction in the number of ER_α-IR cells in the CA1, CA2, CA3, Ce andincrease in the DG, significant reduction in that of ER_β-IR cells in the CA1, CA2, CA3,Ce and increase in the Me, and significant reduction in that of Kal-IR cells in the CA3,DG, Me and Ce.(2)OVX could also notably restrain the augment of animals weight and increase theirimmobility time in FST. Compared with control group, there were significant increasein the number of ER_α-IR cells in the DG and Me, and significant reduction in that ofER_β-IR cells in the CA1, CA2, CA3 and increase in the Me.(3) Compared with Stress group and OVX group, the combination of chronicrestraint stress and OVX could not notably influence the animals weight and theirimmobility time in FST. Compared with Stress group, there were significant increase inthe number of ER_α-IR cells in the CA1, CA3, DG, and Me, significant reduction in thatof ER_β-IR cells in the CA1, CA2, CA3, DG and increase in the Ce, and significantreduction in that of Kal-IR cells in the Me. And compared with OVX group, there weresignificant reduction in the number of ER_α-IR cells in the CA2, DG and increase in theMe and significant reduction in that of ER_β-IR cells in the CA1, CA2, CA3, DG. (4)During the course of chronic restraint stress, female mouse were injected with Eperiodically, and we found that animals weight were notably incresecd and theirimmobility time were reduced remarkably when compared with Stress group. Also therewere significant reduction in the number of ERa-IR cells in the CA1, CA2, DG andincrease in the Me, significant reduction in that of ER_α-IR cells in the CA1, CA2, CA3,DG, Me, and significant increase in that of Kal-IR cells in the CA1, CA2, CA3, DG,Me and Ce.(5)One week after OVX, female mouse were injected with E periodically during thecourse of chronic restraint stress, and we found that animals weight were also notablyincresecd and their immobility time were reduced remarkably when compared withOVX+Stress group. There were significant increase in the number of ER_α-IR cells inthe CA2, DG and ER_β-IR cells in the CA1, CA2, CA3, DG and Ce.All these results suggests that there is a close relation between E and stress-induceddepression. ERT can be an effective treatment for it. ER in the brain may also beconcerned with it. And Kalirin is also involved in the pathology of stress-induceddepression.