老年人大脑皮质内突触生长素定量研究

A quantitative study of synaptophysin of cerebral cortex in the elderly

近年来对脑神经突触小泡上的一种膜内蛋白──突触生长素（ｓｙｎａｐｔｏｐｈｙｓｉｎ）有了比较多的了解。我们利用突触生长素的单克隆抗体做免疫组织化学染色，并用图像分析仪测量吸光度的方法对１０例６９～９４岁临床上无中枢神经系统疾病、病理学检查脑部无明显病变的老年男性尸检病例进行了额叶和颞叶皮质突触生长素的定量研究。发现随着年龄增长，突触生长素阳性部位的吸光度值呈下降趋势，额叶为０．１９０７～０．０７２０，颞叶为０．１６８２～０．０６７６；最高值和最低值之间分别相差１．６３倍和１．４９倍。这种变化反映了老年人大脑皮质突触数量的变化趋势，与其他学者用电子显微镜研究的结果相似。从实验结果看，突触生长素可能是一种神经突触的有效标识蛋白，可以用于普通光学显微镜下对突触进行定量研究。

Abstract An intrinsic membrane protein of brain synaptic vesicles-synaptophysin has been characterized in recent years. The Presence of synaptophysin with the inonoclone antibody against this protein as a marker of synapses in the brain and the relationship between the density of synaptophysin positive particles estimated by ligkt microscopic inimunohistochemistry and aging were studied. The brain tissue samples were obtained from 10 autopsy male cases without pathological changes in central nervous systems. The age is between 69 and 94 years with average of 82.9 years. It was found that the absorbance of positive areas reduced with increase of age. The absorbance value was 0.1907-0.0725 in frontal lobe and 0.1682-0.0676 in temporal lobe. The difference was 1.63 and 1.49 fold between their maximal and minimal values. The result indicates that the density of synaptopbysin, representing the number of synapses, reduces when people get old and it is suggested that synaptophysin might be an effective marker protein for quanlitative study of synapses.