严重创伤后应激障碍早期边缘系统髓鞘碱性蛋白表达与超微结构改变

Alterations of myelin basic protein expression and ultrastructure in limbic system in the early period of stress disorder following severe injury in dogs

目的 进一步探讨严重创伤后应激障碍早期中枢神经系统 (CNS)神经病理学基础。方法 借助犬双后肢低、高速投射物创伤模型 ,采用酶联免疫吸附试验、斑点杂交和神经病理学研究方法 ,观察脑脊液 (CSF)、边缘系统下丘脑、海马及颞顶区脑组织髓鞘碱性蛋白 (MBP)的表达与释放 ,以及CNS超微结构改变。 结果 伤后 8hCSF、低速组下丘脑、高速组下丘脑、海马MBP含量明显增高 (P <0 .0 5和 0 .0 1 ) ,MBPmRNA表达增强 (P <0 .0 5和 0 .0 1 ) ;超微结构变化主要表现为高速组下丘脑、海马神经元变性 ,神经纤维受损。 结论 严重创伤后边缘系统下丘脑、海马结构选择性受损 ,可能为创伤后应激障碍早期重要的病理生理基础之一。CSF中MBP检测是反映CNS应激受损较特异。

Objective To explore the neurobiological mechanism of stress disorder following severe injury in dogs. Methods On the bases of stress model of dogs inflicted with different velocity steel bullet injury to the hind limbs, the expressions and releases of myelin basic protein (MBP), cerebrospinal fluid (CSF), hypothalamus and hippocampus of the limbic system and temporoparietal area were detected with ELISA and dot blot hybridization as well as the ultrastructural study on brain tissues. Results MBP level was increased markedly in CSF and hypothalamus in low speed group, hypothalamus and hippocampus in high speed group 8 hours after injury ( P <0.05 and 0.01). While the expression of MBP mRNA was significantly enhanced in hypothalamus in low speed group ( P <0.05 and 0.01), and in both the hypothalamus and hippocamus in high speed group ( P <0.01). At the same time, neuronal degeneration and nerve fibers demyelination were seen in the hypothalamus and hippocampus in high speed group. Conclusions The hypothalamus and hippocampus are vulnerable to be damaged after severe injury, which may be one of the important pathophysiological bases for changes in the early stage of posttraumatic stress disorder (PTSD). The CSF MBP detection may serve as a sensitive indicator for CNS damage in stress disorder.