慢性应激对大鼠前额叶脑源性神经营养因子表达的影响

目的 探讨慢性应激、前额叶神经元细胞活性变化和抑郁症之间的关系.方法 采用慢性不可预见性应激同孤养结合制作抑郁症模型,实验第22天杀死所有大鼠,采取灌注取材与切片的方法制作脑冠状切片,采用免疫组化ABC法检测切片中的脑源性神经营养因子(BDNF)蛋白,在计算机图像分析系统上分别测量双侧前额叶BDNF阳性细胞的平均光密度值,采用SPSSll.5统计软件对数据进行分析.结果 21 d后,实验组与对照组相比,体质量明显下降(225.80±6.16)g vs(249.00±9.93)g,t=2.915,P<0.05)]、中央格停留时间延长(10.20±3.82)s vs(5.60±2.70)s,t=2.388,P<0.05)]、水平穿越格数减少(t=6.245,P<0.01)、直立次数减少(t=2.693,P<0.05)、修饰次数减少(t=2.685,P<0.05)、粪便粒数增多(t=3.846,P<0.01).光镜下观察,实验组大鼠前额叶皮质BDNF阳性细胞数量明显减少,且多数细胞呈空泡状,胞浆着色很浅.其中以右侧区明显.左右PFC区正常组大鼠BDNF的光密度均高于实验组.经过21 d应激后,实验组左右PFC区的BDNF表达均低于正常对照组(P<0.01),但右PFC区显著,同应激后左PFC比较,差异具有显著性.结论 BDNF在正常大鼠左右PFC区分布无明显差异.经过慢性应激后,大鼠左右PFC区的BDNF表达均明显下降,右侧区受损严重.

The impact of chronic stress on the behaviors and the expression of brain-derived neurotrophic factor in the prefrontal cortex of rats

Objective To study the relation between chronic stressful, the neural changes in prefrontal cortex and depression. Methods Adapt chronic unpredictable stress with separate model to make depression model rats. After 22 days all the rats were killed and use immunohistochemistry method and computer image analysis to detect BDNF. To analysis the date with SPSS11.5 software. Results After 21 days stress, body weight ( t =2.915, P < 0.05), ambulation ( t = 6. 245, P < 0. 01 ), rearing( t = 2.693, P < 0. 05 ) and grooming ( t = 2. 685, P<0.05) decreased and stopping time in center( t=2. 388, P<0. 05) ,defecation( t =3. 846, P<0. 01 ) increased in experimental group. BDNF expressed obviously in control group and the prefrontal cortex expressed highly than that of the experimental group. BDNF expressions of experimental group were lower than that in control group ( P< 0.01 ) especially in right prefrontal cortex. Conclusion There was no difference of BDNF distribution in prefrontal cortex between both groups ,but after 21 days stress ,the BDNF levels of experimental rats obviously descent,especially in right prefrontal cortex.