Disector方法观察缺氧缺血新生大鼠脑海马CA1区锥体细胞层神经元形态计量学改变

Unbiased stereological estimation of morphometric changes of pyramidal neurons in hippocampal CA1 during hypoxic-ischemic brain damage in newborn rats

应用Ｄｉｓｅｃｔｏｒ方法观察缺氧缺血性脑损伤新生大鼠脑选择性易损区海马ＣＡ１区锥体细胞层神经元形态计量学改变。结果显示，与正常对照组相比，缺氧缺血后三周新生大鼠海马ＣＡ１区锥体细胞层神经元数密度减少３８％，体密度减少４７％，表面积密度减少３３％，比表面增加２５％，圆球度减少１６％，统计学均有显著性差异。而细胞核平均体积及平均表面积的改变无统计学意义。Ｄｉｓｅｃｔｏｒ为三维测试系统，可直接在三维空间计数粒子，不受粒子大小、形状、取向的影响。适当选择切片厚度及相邻两切片间的距离，可无偏地估计神经元数目及其大小。

In this study, Disector, one of the unbiased stereological methods, was used to estimate the morphometric changes of pyramidal neurons in hippocampal CA1 in newborn rats with hypoxic ischemic brain damage. It was showed that the numerical density of pyramidal neurons was decreased 38%(n=4, P<0 01)in newborn rats at day 21th after hypoxic-ischemia. The volume density of neuron nuclei was decreased 47%(P<0 01). The surface density decreased 33%(P<0 01), specific surface increased 25%(P<0 05), and the sphere grade decreased 16%(P<0 01). While the decrease of mean volume and the increase of mean surface of nuclei had no statistical significance compared with control. In conclusion, the Disector is a probe which samples particles with a uniform probability in 3 dimensional space, irrespective of their size and shape. Thus, if the thickness of section and the distance between two adjacent sections are appropriate, the number and size of neurons may be estimated unbiasely.