McKerracher L, Hirscheimer A
Centre for Research in Neuroscience, Montreal General Hospital Research Institute, Quebec, Canada.
J Neurobiol. 1992 Jul;23(5):568-78. doi: 10.1002/neu.480230510.
The delivery of cytoskeletal proteins to the axon occurs by slow axonal transport. We examined how the rate of slow transport was altered after axonal injury. When retinal ganglion cell (RGC) axons regenerated through peripheral nerve grafts, an increase in the rate of slow transport occurred during regrowth of the injured axons. We compared these results to axonal injury in the optic nerve where no substantial regrowth occurs and found a completely different response. Slow transport was decreased approximately tenfold in rate in the proximal segment of crushed optic nerves. This decreased rate of slow transport was not induced immediately, but occurred about 1 week after injury. To explore whether a decrease in the rate of slow transport was induced when the regeneration of peripheral nerves was physically blocked, we examined slow transport in motor neurons after the sciatic nerve was transected and ligated. In this case, no change in the rate of the comigrating tubulin and neurofilament (NF) radioactive peaks were observed. We discuss how the changes in the rate of slow transport may reflect different neuronal responses to injury and speculate about the possible molecular changes in the expression of tubulin which may contribute to the observed changes.
细胞骨架蛋白通过轴突慢速运输被输送到轴突。我们研究了轴突损伤后慢速运输速率是如何改变的。当视网膜神经节细胞（RGC）轴突通过周围神经移植进行再生时，受损轴突再生过程中慢速运输速率会增加。我们将这些结果与视神经损伤（此处无实质性再生）的情况进行比较，发现了完全不同的反应。在挤压视神经的近端节段，慢速运输速率下降了约十倍。这种慢速运输速率的下降不是立即发生的，而是在损伤后约1周出现。为了探究当周围神经再生受到物理阻断时，慢速运输速率是否会下降，我们在坐骨神经横断并结扎后检测了运动神经元中的慢速运输。在这种情况下，未观察到共迁移的微管蛋白和神经丝（NF）放射性峰的速率有变化。我们讨论了慢速运输速率的变化如何反映神经元对损伤的不同反应，并推测了微管蛋白表达中可能导致观察到的变化的分子变化。
