Carlson J, Lais A C, Dyck P J
J Neuropathol Exp Neurol. 1979 Nov;38(6):579-85. doi: 10.1097/00005072-197911000-00002.
The peripheral axons of lower motor and spinal ganglion neurons were permanently transected and not allowed to regrow to target tissue in adult cats by amputation of the hind limb at the hip. The number and sizes of L-7 lower motor neurons at two levels (cell bodies of lateral group motor neurons and myelinated fibers [MFs] of ventral root) and of L-7 spinal ganglion neurons at two levels (cell bodies of L-7 spinal ganglion and MFs of dorsal root) were morphometrically evaluated in groups of cats at 3 months, 9 months, and 18 months after amputation and compared with the number and sizes of neurons in controls or with those on the opposite side. The number of neurons decreased only minimally after amputation. The diameter of neuron cell bodies was only equivocally reduced. By contrast, the median diameter and the peak diameter of both large and small MFs of dorsal and ventral nerve roots were significantly (approximately 30%) less than those of controls. This reduction in diameter of MFs is judged to be related to chronic axonal atrophy rather than to selective loss of large fibers. Permanent transection of distal axons should therefore prove to be a good model of chronic axonal atrophy.
通过在髋关节处截肢后肢，成年猫的下运动神经元和脊神经节神经元的外周轴突被永久性横断，且不允许其向靶组织再生。在截肢后3个月、9个月和18个月的猫群中，对两个水平的L-7下运动神经元（外侧组运动神经元的胞体和腹根的有髓纤维[MFs]）以及两个水平的L-7脊神经节神经元（L-7脊神经节的胞体和背根的MFs）的数量和大小进行形态计量学评估，并与对照组神经元的数量和大小或与对侧的神经元数量和大小进行比较。截肢后神经元数量仅略有减少。神经元胞体的直径仅略有减小。相比之下，背根和腹根的大、小MFs的中位直径和峰值直径均显著小于对照组（约30%）。MFs直径的这种减小被认为与慢性轴突萎缩有关，而非与大纤维的选择性丢失有关。因此，远端轴突的永久性横断应被证明是慢性轴突萎缩的一个良好模型。
