Reh T A, Redshaw J D, Bisby M A
Brain Res. 1987 Apr;388(1):1-6. doi: 10.1016/0169-328x(87)90014-3.
We compared the effects of axotomy on the composition of fast axonally transported proteins in rat sciatic sensory axons and pyramidal tract axons, 7 days after axotomy. L-[35S]methionine was administered to dorsal root ganglia or sensorimotor cortex and after 6 or 4 h, respectively, labelled proteins were obtained from sciatic nerve or pyramidal tract. Transported proteins were characterized by one- and two-dimensional electrophoresis, followed by fluorography. As previously reported, sciatic axotomy produced changes in the labelling of fast-transported proteins, notably, increased labelling of a spot designated GAP43. In contrast axotomy of pyramidal axons produced no increased labelling of GAP43, although it could be identified in both normal and axotomized samples. Autoradiography of spinal cord distal to the lesion confirmed that our procedures did indeed label axons and that the axotomy did interrupt these axons. Our finding that axotomy does not stimulate changes in composition of fast-transported proteins in the corticospinal tract agrees with previous studies on mammalian retinal ganglion cell axons and leads us to conclude that this failure to respond to axotomy is a general feature of non-regenerating CNS axons.
我们比较了轴突切断术后7天，切断大鼠坐骨神经感觉轴突和锥体束轴突对快速轴浆运输蛋白组成的影响。将L-[35S]甲硫氨酸分别注入背根神经节或感觉运动皮层，6小时或4小时后，分别从坐骨神经或锥体束获取标记蛋白。通过一维和二维电泳对运输蛋白进行表征，随后进行荧光自显影。如先前报道，坐骨神经轴突切断术导致快速运输蛋白的标记发生变化，特别是标记为GAP43的斑点的标记增加。相比之下，锥体轴突切断术并未导致GAP43的标记增加，尽管在正常和轴突切断的样本中均能识别出它。损伤部位远端脊髓的放射自显影证实，我们的操作确实标记了轴突，并且轴突切断术确实中断了这些轴突。我们发现轴突切断术不会刺激皮质脊髓束中快速运输蛋白的组成发生变化，这与先前对哺乳动物视网膜神经节细胞轴突的研究一致，并使我们得出结论，这种对轴突切断术无反应是中枢神经系统非再生轴突的一个普遍特征。
