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目的:探讨早期母婴分离应激联合成年慢性不可预知性应激制备成年SD大鼠抑郁模型，观察大鼠行为学表现和突触蛋白的表达。方法:将刚出生的24只雄性大鼠随机分为空白组(CON组)、慢性不可预知性应激组(CUMS组)、母婴分离联合慢性不可预知性应激组(MS＋CUMS组)，每组8只。CUMS组大鼠成年期采用慢性不可预知性应激(chronic unpredictable mild stress，CUMS)建立抑郁模型，MS＋CUMS组大鼠采用母婴分离＋慢性不可预知性应激建立大鼠成年期抑郁模型。采用体质量和外观观察、糖水偏好实验、旷场实验、强迫游泳实验评价大鼠抑郁模型；免疫组化检测海马中Syn的表达以及Western blot检测大鼠海马PSD-95、Syn蛋白表达水平。结果:(1)应激造模结束后，与CON组相比，CUMS组和MS＋CUMS组大鼠体质量明显降低[(126.43±3.88) g，(91.04±3.85) g，(69.89±6.67) g；n t＝5.03，8.03，均n P<0.01]，糖水偏好度显著下降[(94.21±0.56)%，(79.30±1.13)%，(72.73±1.82)%；n t＝8.24，11.87，均n P<0.01)，不动时间明显增加[(3.50±0.84) s，(13.59±2.40) s，(15.70±2.97) s；n t＝3.16，3.82，均n P<0.01]；其中，MS＋CUMS组的体质量和糖水偏好度比CUMS组大鼠的更低(n t＝3.00，3.63，均n P<0.01)。(2)与正常组相比，MS＋CUMS大鼠的中央区域活动时间明显缩短[(21.41±4.65) s，(8.96±2.37) s；n t＝2.66，n P<0.05]。(3)在免疫组化实验中，与正常组相比，CUMS组和MS＋CUMS组大鼠海马Syn阳性面积百分比明显减少[(24.42±0.76)%，(14.00±0.95)%，(10.38±1.38)%；n t＝6.93，9.33，n P<0.01)]。(4)Western blot结果显示，与CON组相比，CUMS组和MS＋CUMS组大鼠海马中PSD-95[(1.18±0.02)，(0.74±0.06)，(0.52±0.05)；n t＝6.29，9.31，均n P<0.05]和Syn[(1.12±0.08)，(0.95±0.06)，(0.90±0.07)；n t＝3.10，4.04，均n P<0.05]蛋白的表达情况明显下降；其中，与CUMS组相比，MS＋CUMS组的PSD-95的蛋白表达更低[(0.74±0.06)，(0.52±0.05)；n t＝0.93，n P<0.05]。n 结论:母婴分离联合CUMS应激造模能诱发大鼠出现抑郁样行为，降低海马突触可塑性相关蛋白的表达。“,”Objective:To explore the establishment and assessment of the depression model of adult SD rats induced by early maternal infant separation stress combined with adult chronic unpredictable mild stress(CUMS), and to observe the behavior and synaptic protein expression of SD rats.Methods:Twenty-four male rats were randomly divided into three groups: control group (CON group), chronic unpredictable stress group (CUMS group), maternal infant separation combined with chronic unpredictable stress group (MS + CUMS group). The depression model of rats in cums group was established by CUMS, and the depression model of rats in MS + CUMS group was established by maternal infant separation + CUMS. The depression model was evaluated by body mass and appearance observation, sugar water preference experiment, open field test and forced swimming test.Synapse-associated proteins (PSD-95 and synaptophysin (Syn)) of the hippocampus were assayed using Western blot. Syn protein expression was measured by immunohistochemistry.Results:After modeling, compared with CON group, the rats in CUMS group and MS + CUMS group had significantly lower body mass((126.43±3.88) g, (91.04±3.85) g, (69.89±6.67) g; n t=5.03, 8.03, both n P<0.01), significantly lower sugar water preference((94.21±0.56)%, (79.30±1.13)%, (72.73±1.82)%;n t=8.24, 11.87, both n P<0.01) and significantly increased immobility time((3.50±0.84)s, (13.59±2.40)s, (15.70±2.97)s;n t=3.16, 3.82, both n P<0.01). Among them, the body mass and sugar water preference of MS + CUMS group were lower than those of CUMS group (n t=3.00, 3.63; both n P<0.01). (2)The center time of the rats in MS+ CUMS group markedly reduced compared with that of CON group((21.41±4.65) s, (8.96±2.37) s;n t=2.66, n P<0.05). (3)In the immunohistochemistry experiment, compared with the CON group, the percentage of Syn positive area in hippocampus of rats in CUMS group and MS+ CUMS group decreased significantly ((24.42±0.76)%, (14.00±0.95)%, (10.38±1.38)%;n t=6.93, 9.33, n P<0.01). (4)The results of Western blot showed that compared with CON group, both the expression of PSD-95 ((1.18±0.02), (0.74±0.06), (0.52±0.05),n t=6.29, 9.31; both n P<0.05) and Syn ((1.12±0.08), (0.95±0.06), (0.90±0.07);n t=3.10, 4.04; both n P<0.05) in hippocampus of rats in CUMS group and MS+ CUMS group were significantly decreased.And compared with the CUMS group, the expression of PSD-95 in MS+ CUMS group was lower(n t=0.93, n P<0.05).n Conclusion:The method of MS combined with CUMS can effectively induce depression like behavior and decrease the expression of synaptic plasticity related protein of hippocampus in rats.