Chronic Psychosocial Stress Causes Apical Dendritic Atrophy of Hippocampal CA3 Pyramidal Neurons in Subordinate Tree Shrews
Chronic Psychosocial Stress Causes Apical Dendritic Atrophy of Hippocampal CA3 Pyramidal Neurons in Subordinate Tree Shrews
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DOI：
10.1523/jneurosci.16-10-03534.1996
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发表时间：
1996-05
期刊：
影响因子：
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通讯作者：
A. Magariños;B. McEwen;G. Flügge;E. Fuchs
中科院分区：
文献类型：
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作者：
A. Magariños;B. McEwen;G. Flügge;E. Fuchs
我们以前已经表明，反复实验室束缚应激或每日皮质酮管理影响大鼠海马CA 3区神经元的结构。在本研究中，我们研究了重复的日常心理社会应激对雄性树鼩海马CA 3区锥体神经元结构的影响。雄性树鼩发展出社会等级制度，在这种制度中，当面对统治者时，下属在生理和行为参数上表现出特征性的变化。在本实验中，从属动物体重下降后不久，开始每天的社会冲突，并在整个实验中皮质醇的尿排泄量升高，与对照组相比。从下属暴露于28天（1小时/天）的社会对抗高尔基浸渍脑组织进行了比较，从控制非应激动物。与对照组相比，来自下级的CA 3锥体细胞的顶树突的分支点数和总树突长度减少。在顶端树突棘密度或基底树突树形态中没有观察到差异。通过每日口服抗癫痫药物苯妥英（Dilantin，Sigma，St. Louis，MO）（200 mg/kg）（其干扰兴奋性氨基酸（EAA）作用），可预防下级中应激诱导的CA 3顶端树突萎缩。这些结果表明，自然应激或心理社会应激诱导了从属雄性树鼩海马神经元的特异性结构变化。这些变化，像那些在大鼠糖皮质激素治疗或束缚应激后，可能是介导的激活下丘脑-垂体-肾上腺轴与内源性EAA合作从苔藓纤维输入。
We have shown previously that repeated laboratory restraint stress or daily corticosterone administration affects the structure of CA3 hippocampal neurons in rats. In the present study, we investigated the effect of repeated daily psychosocial stress on the structure of hippocampal CA3 pyramidal neurons in male tree shrews (Tupaia belangeri). Male tree shrews develop social hierarchies in which subordinates show characteristic changes in physiological and behavioral parameters when confronted with a dominant. In the present experiments, subordinate animals lost body weight soon after starting the daily social conflict, and urinary excretion of cortisol was elevated throughout the experiment as compared with the control period. Golgi-impregnated brain tissue from subordinates exposed to 28 d (1 hr/d) of social confrontations was compared with that fromcontrol nonstressed animals. The apical dendrites of the CA3 pyramidal cells from subordinates had a decreased number of branch points and total dendritic length as compared with controls. No differences were observed in apical dendritic spine density or in the basal dendritic tree morphology. The stress-induced CA3 apical dendritic atrophy in subordinates was prevented by administering daily oral doses of the antiepileptic drug phenytoin (Dilantin, Sigma, St. Louis, MO) (200 mg/kg), which interferes with excitatory amino acid (EAA) action. These results suggest that the naturalistic stressorpsychosocial stress induces specific structural changes in hippocampal neurons of subordinate male tree shrews. These changes, like those in the rat after glucocorticoid treatment or restraint stress, probably are mediated by activation of the hypothalamo–pituitary–adrenal-axis acting in concert with endogenous EAAs from mossy fiber input.