Quantitative analysis of astrocytic processes

1)应用计算机断层扫描（CT）技术和高压电子显微镜技术对星形胶质细胞突起的三维结构分析：取大鼠海马和大脑皮层的原生质体星形胶质细胞，经Golgi染色和塑料包埋，制成厚切片（2-3 μ m）。通过以2个间隔将样品台从-60倾斜到+60来拍摄一系列倾斜高压电子显微照片。通过计算机断层扫描技术对这些倾斜图像进行三维形态测量分析。我们使用ONIX REALENGIN II计算机进行图像分析。我们成功地在三维成像的中柱细胞过程。对星形胶质细胞突起的表面积和体积的估算研究正在进行中。2）免疫细胞化学染色显示不同脑区星形胶质细胞。用抗胶质蛋白S-100抗体，光镜下观察.图像与高尔基体浸渍技术染色的图像相似。用免疫染色标本和高压电镜对星形胶质细胞突起进行CT分析，发现免疫染色材料的对比度不足以进行高压电镜CT分析。3）我们制作了一个特殊的物镜透镜，使电子束平行于样品位置，并使物镜孔径位于物镜透镜的后焦平面上成为可能。结果，样品的对比度得到了很大的改善，我们的研究可以期待进一步的改进。

1) Three dimensional analysis of astrocytic processes by means of the computer tomography (CT) technique and high voltage electron microscopy : Thick sections (2-3 m thick) of protoplasmic astrocytes hippocampus and cerebral cortex of rats were prepared from Golgi stained and plastic embedded materials. Series of tilted high voltage electron micrographs were taken by tilting the specimen stage from -60 to +60 with 2 intervals. Three dimensional morphometrical analysis of these tilted images were performed by means of computer tomography technique. We used an ONIX REALENGIN II computer for image analysis. We succeeded in three dimensional imaging of strocytic processes. The research of estimating the surface area and volume of the astrocytic processes are now in progress.2) Astrocytes in various brain areas were stained immunocytochemically. Using an anatibody against glial protein, S 100, and observed under the light microscope. Images were similar to those stained with the Golgi impregnation technique. CT analysis of astrocytic processes was performed using the immunostained specimens and high voltage electron microscopy.It was found that the contrast of the immunostained material was not high enough for the high voltage electron microscope CT analysis. We are trying to find out other contrasting techniques for high voltage electron microscopy.3) We made a special objective lens to get a parallel electron beam at the specimen position, and to make possible in positioning the objective aperture on the back focal plane of the objective lens. As a result the contrast of the specimen improved very much, and further improvements in our research can be expected.