Zhang Wei, Li Chen, Yang Shu, Xu Cang, Wang Weiwei, Nyengaard Jens R, Tang Yong
Institute for Basic Medical Sciences, Chongqing Medical University, Chongqing, PR China.
J Neurosci Methods. 2008 Jul 15;172(1):21-6. doi: 10.1016/j.jneumeth.2008.04.005. Epub 2008 Apr 14.
An efficient and unbiased stereological technique to estimate the total length and total volume of the myelinated fibers in rat cortex is described. Unbiased sampling and measuring principles enable to obtain an unbiased estimation of the true value. In the present design, six tissue blocks were obtained from the entire rat brain cortex in a uniform random fashion. Isotropic, uniform random (IUR) sections were ensured by the use of the isector technique. One section with the thickness of 60 nm was cut from the center of each epon block using an ultramicrotome. Five fields of vision were photographed using electron microscopy. The length density of the myelinated fibers in the cortex was estimated using an unbiased counting frame. The volume density of the myelinated fibers in the cortex was estimated with point counting. The total length and total volume of the myelinated fibers in the cortex were estimated by multiplying the volume of the cortex, obtained using the Cavalieri principle and the length density and volume density of the fibers in the cortex. The sampling variance introduced by the stereological estimation procedure was a small fraction of the observed total variance indicating an efficient sampling protocol.
本文描述了一种高效且无偏倚的体视学技术，用于估计大鼠皮质中髓鞘纤维的总长度和总体积。无偏倚的抽样和测量原则能够对真实值进行无偏倚估计。在当前设计中，以均匀随机的方式从整个大鼠脑皮质获取六个组织块。通过使用等距切片技术确保获得各向同性、均匀随机（IUR）切片。使用超薄切片机从每个环氧树脂包埋块的中心切出一片厚度为60纳米的切片。使用电子显微镜拍摄五个视野。使用无偏倚计数框估计皮质中髓鞘纤维的长度密度。通过点计数估计皮质中髓鞘纤维的体积密度。通过将使用卡瓦列里原理获得的皮质体积与皮质中纤维的长度密度和体积密度相乘，估计皮质中髓鞘纤维的总长度和总体积。体视学估计程序引入的抽样方差仅占观察到的总方差的一小部分，表明该抽样方案是有效的。
