运用新的体视学方法研究大鼠胼胝体及胼胝体额区有髓神经纤维  

Rat corpus callosum and myelinated nerve fibers in its frontal region by a new stereological method

作　　者：徐瑲[1] 李琛[1,2] 杨姝[1,2] 张伟[1] 卢伟[1] 唐勇[1,2] 

机构地区：[1]重庆医科大学组织胚胎学教研室,重庆400016 [2]重庆医科大学附属第一医院神经内科,重庆400016

出　　处：《第三军医大学学报》2009年第1期56-59,共4页Journal of Third Military Medical University

基　　金：国家自然科学基金(30440082,30572075);国家人事部2005年度高层次留学人才回国工作资助经费;教育部2006年留学回国人员科研启动基金;教育部2006年重点项目;重庆市自然科学基金(CSTC2005BB5034)~~

摘　　要：目的建立定量研究胼胝体体积及胼胝体额区有髓神经纤维的体视学方法。方法运用卡瓦列里原理计算胼胝体和胼胝体额区体积。采用随机抽样原则在胼胝体额区切取组织块,用"球切法"保证满足三维空间内各向同性抽样原则后,用超薄切片机切取60nm厚的超薄切片,在透射电子显微镜下从每张切片随机拍摄4个视野。使用无偏计数框计算胼胝体额区有髓神经纤维长度密度,使用等距测试点计算胼胝体额区有髓神经纤维体积密度。胼胝体额区内有髓神经纤维的长度密度和体积密度分别乘以胼胝体额区的体积就得到了胼胝体额区内有髓神经纤维的总长度和总体积。测量所有被无偏计数框计数的有髓神经纤维的直径。与纤维断面的最长轴相垂直的所有横轴中最长的1条横径为其直径。结果大鼠胼胝体的体积为(70.67±5.64)mm3,胼胝体额区体积为(15.29±1.62)mm3,胼胝体额区有髓神经纤维的总长度为(16.01±2.28)km,胼胝体额区有髓神经纤维的总体积为(9.11±0.44)mm3,胼胝体额区有髓神经纤维髓鞘的总体积为(3.91±0.40)mm3。胼胝体额区有髓神经纤维的直径为(0.58±0.05)μm。结论本研究建立了定量研究胼胝体体积和胼胝体额区内有髓神经纤维总长度、总体积和有髓神经纤维直径的研究方法。Objective To establish a stereological method for the quantitative study on corpus eallosum and the myelinated nerve fibers in its callosal frontal region. Methods The volume of corpus callosum and the volume of its frontal region were estimated using the Cavalieri＇ s principle. The tissue blocks were obtained from the frontal region of corpus callosum in an uniform random fashion. Isotropic, uniform and random （IUR） sec- tions were ensured by using isector technique. Sections with the thickness of 60 nm were cut from each epon block by using an uhramicrotome. From each section, 4 fields of vision were randomly photographed using electron microscopy. The length density of the myelinated fibers in the frontal region of rat corpus callosum was estimated using an unbiased counting frame. The volume density of the fibers was estimated using point counting. The total length and total volume of the myelinated fibers in the region were estimated by muhiplying the length density and volume density of these fibers by the volume of the frontal region, respectively. Iqesults The volume of rat corpus callosum was （70.67 ±5.64） mm3, and the volume of its frontal region was （ 15.29 ± 1.62） mm3. The total length of these myelinated fibers was （16.01 ±2.28） kin, and their total volume was （9.11 ± 0.44） mm3. The total volume of the myelin sheaths in the frontal region of rat corpus callosum was （3.91 ±0.40） mm3. The diameter of these myelinated fibers was （0.58±0.05 ） μm. Conclusion We describe a stereological method that can be used to quantitatively investigate the volume of corpus callosum and the myelinated nerve fibers in the frontal region of corpus callosum. The method will be as a useful tool for the future studies of the changes of corpus callosum in normal aging and in various neurodegenerative diseases.

关 键 词：胼胝体 有髓神经纤维 大鼠 体视学 

分 类 号：R311[医药卫生—基础医学] R322.81