老年抑郁大鼠海马CA3区c-fos和Caspase-3蛋白的表达

目的:探讨慢性应激老年抑郁大鼠海马CA3区c-fos和Caspase-3蛋白的表达,以探讨老年抑郁症的发病机制。方法:将20只Wistar老年大鼠随机分为实验组和对照组,每组10只。实验组大鼠每天强迫游泳20 min,并每周给予电刺激和强光照射各1次,经过21 d应激制作老年大鼠慢性应激抑郁模型,对照组正常喂养,不给予上述处理。采用特异性抗体标记的免疫组织化学方法,检测实验21 d后老年大鼠海马CA3区c-fos和Caspase-3蛋白的表达情况,并观察大鼠开场行为和排便情况。结果:①实验组老年大鼠中央格停留时间延长,水平穿越格数减少,修饰行为减少,排便次数增多;②c-fos平均灰度值:实验组(166.56±9.73),对照组(149.62±12.91),有显著差异P=0.000;③阳性细胞数:实验组(41.12±4.72),对照组(31.12±3.25),P=0.000;④caspase-3平均灰度值:实验组(202.59±2.64),对照组(179.74±8.24),有显著差异P=0.000;⑤阳性细胞数:实验组(24.73±2.57),对照组(18.86±1.13),有显著差异P=0.000。结论:慢性应激老年抑郁大鼠海马CA3区c-fos和caspase-3蛋白表达增加,行为表现异常,可能与慢性应激所致细胞凋亡增强,海马区脑组织损伤有关。

Expression of c-fos and Caspase-3 Protein in Geriatric Rats Hippocampus CA3 Area Induced by Chronic Unpredictable Mild Stress

Objective:To observe the expression of c-fos and caspase-3 protein in geriatric rats hippocampus CA3 area induced by chronic unpredictable mild stress in order to understand the nosogenesis of depression.Methods:Twenty geriatric Wistar rats were randomizedly and equally divided into experimental group and control group.In experimental group,rats were forced to swim 20 minutes each day plus electricity stimulation and tail sting once a week,in control group,no special intervention were added.After 21 days,the expression of c-fos and caspase-3 protein were detected by immunohistochemistry marked by special antibodies,meanwhile,the open-field behavior and defecation condition before and after experiment were observed.Results:In experimental group,geriatric rats showed prolonged immobility time,ambulation and modification time decreased,feces increased;c-fos mean gray scale(202.59±2.64 vs 179.74±8.24,P=0.000),positive cell numbers(41.12±4.72 vs 31.12±3.25,P=0.000),caspase-3 mean gray scale(202.59±2.64 vs 179.74±8.24,P=0.000)and positive cell numbers(24.73±2.57 vs 18.86±1.13,P=0.000) were higher than in control group.Conclusion:The expression of c-fos and caspase-3 protein increased in hippocampus CA3 area of geriatric rats induced by chronic unpredictable mild stress,and behaviors showed abnormal,which might be related to the up-regulation of cell apoptosis and the brain damage in hippocampus induced by chronic stress.