Tandrup T
Department of Neurology, University Hospital of Arhus, Denmark.
J Comp Neurol. 1995 Jul 3;357(3):341-7. doi: 10.1002/cne.903570302.
The neurons in the dorsal root ganglion have classically been described as pseudounipolar. Previous studies have questioned this simple organisation because an equality between the number of fibres in the dorsal root and neurons could not be established. In this study the number of neurons in the fifth lumbar dorsal root ganglion of the adult rat is compared to the number of fibres in the dorsal root. The methods used are founded on unbiased stereological principles and includes the optical disector, the Cavalieri principle, unbiased counting rules in two and three dimensions, and systematic random sampling. The number of A- and B-cells is estimated with light microscopy, and the number of myelinated and unmyelinated fibres is estimated with electron microscopy. The present study demonstrates that there is a 1:1 ratio (mean: 0.98, CV: 0.12, 95% confidence interval: 0.90-1.07) of fibres in the dorsal root to neurons in the dorsal root ganglion, as the classical theory predicts. Furthermore, the study of the two neuron subtypes supports the hypothesis that myelinated fibres originate from the A-cells and the unmyelinated fibres from the B-cells.
背根神经节中的神经元传统上被描述为假单极神经元。以往的研究对这种简单的结构提出了质疑，因为无法确定背根中的纤维数量与神经元数量之间的相等关系。在本研究中，将成年大鼠第五腰段背根神经节中的神经元数量与背根中的纤维数量进行了比较。所使用的方法基于无偏倚的体视学原理，包括光学分割器、卡瓦列里原理、二维和三维的无偏计数规则以及系统随机抽样。通过光学显微镜估计A细胞和B细胞的数量，通过电子显微镜估计有髓纤维和无髓纤维的数量。本研究表明，正如经典理论所预测的那样，背根中的纤维与背根神经节中的神经元之比为1:1（平均值：0.98，变异系数：0.12，95%置信区间：0.90 - 1.07）。此外，对两种神经元亚型的研究支持了以下假设：有髓纤维起源于A细胞，无髓纤维起源于B细胞。
