Objective To explore the impact of chronic unpredictable mild stress on behaviors and hippocam-pal neurons microtubules. Methods Twenty - four male rats were randomly divided into three groups, with 8 rats as chronic unpredicted mild stresses group (CUMS) , 8 rats as the fluoxetine administrated group and 8 as normal controls. After 6 weeks ,behavioral changes in these rats were analyzed in an open -field paradigm. The expression of hippocampal cytoskeletal microtubulin ( Acet - Tub or Tyr - Tub ) were analyzed using Western Blot. Results (1) Compared with the normal rats, sucrose prefereneet total traveling distance, velocity and frequencies of rearing were significantly reduced in the depressed rats( P ＜ 0. 01); Behavioral changes could be reversed after 21 day fluoxetine treatment;( 2) The western blotting results showed that compared with the normal rats, the Acet - Tub expression of CUMS group showed a significant increase ( P ＜ 0. 01) and Tyr - Tub expression of CUMS group was significantly decreased following CUMS stress ( P ＜ 0. 01 ). Conclusion These findings provide evidence that rats exposed to chronic unpredicted mild stresses showed impairment of cytoskeletal microtubular dynamic and structural neuronal plasticity, providing insight into the role of cytoskeleton in the depression.%目的 研究慢性不可预测性温和应激对大鼠行为及海马微管蛋白表达的影响.方法 将SD雄性大鼠24只随机分为对照组、慢性不可预测性温、应激组(chronic unpredicted mild stress,CUMS组)和氟西汀组,每组8只.在实验结束后对三组大鼠进行行为学观察,检测海马微管蛋白的表达.结果 CUMS组大鼠总行程、平均运动速度、直立次数及糖水偏好低于对照组(P＜0.01)；氟西汀组行为学评价指标与对照组比较差异无统计学意义(P＞0.05).免疫印迹结果显示CUMS组海马乙酰化微管蛋白(Acet-Tub)表达升高,酪氨酸化微管蛋白(Tyr-Tub)表达减低,与对照组比较差异有统计学意义(P＜0.01)；经氟西汀处理后,Acet-Tub表达降低,Tyr-Tub表达升高,与CUMS组比较差异有统计学意义(P＜0.01).结论 慢性不可预测性温和应激能降低大鼠海马微管系统的动态性,损害神经可塑性,氟西汀可以逆转损害的微管结构,可能是抑郁样行为的分子机制.
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