大鼠海马神经元及其线粒体增龄性改变的形态计量分析

A morphometric study of age related changes in neurons and mitochondria of hippocampus in rats

目的探讨大鼠海马神经元及其线粒体形态结构增龄性改变的程度及性质。方法应用组织化学及电镜技术，通过计算机图像分析系统对海马神经元及其线粒体结构进行形态计量分析。结果海马ＣＡ１和ＣＡ３区神经元随增龄出现细胞皱缩，ＣＡ３区神经元数密度在老年组较青年组显著减少（Ｐ＜０．０５），ＣＡ１区神经元数密度各月龄组之间差异无显著性（Ｐ＞０．０５）。ＣＡ３区神经元胞体内线粒体体密度、数密度、比表面及嵴膜密度随增龄而减少，线粒体平均体积及平均截面积随增龄而增大。结论海马神经元及其线粒体形态结构随增龄发生显著性改变，这些形态结构的改变可能是大鼠海马老化的指征。

Objective To study the age related structural changes of neurons and mitochondria of hippocampus in young (3 month), adult (12 month) and old (24 month) Spraque Dawley rats. Methods By histochemistry and electron microscopy, morphometric quantitative study of neurons and mitochondria of hippocampus was investigated with true color medical image analysis system. Results The neurons of CA 1 and CA 3 hippocampal subfields became shrinkage with aging. The numerical density of neurons in the CA 3 subfield was decreased in old rats ( P <0 05) but no change in CA 1 subfield. The mitochondrial volume density, numerical density, specific surface and membrane density of cristae were decreased ( P <0 05), and the mitochondrial average cross sectional area and average volume increased with aging in the neuron body of CA 3 subfield ( P <0 05). Conclusions The salient changes of neurons and mitochondria of hippocampus during aging may be the indication of aging of hippocampus in rats.