Kalia M, Deshpande S S, Ducker T, Albuquerque E X
Exp Neurol. 1983 Aug;81(2):407-25. doi: 10.1016/0014-4886(83)90272-8.
The retrograde transport of HRP was used to determine the status of axonal transport in the peroneal and sciatic nerves of hibernating and nonhibernating ground squirrels following crush of the peroneal nerve at 10 to 12 mm (SNS) or sciatic nerve at 33 to 35 mm (LNS) from its entrance into the extensor muscle. The ability of the proximal segment to reestablish axonal continuity and thus neuromuscular transmission was also studied. Two weeks to 3 months after nerve crush the extensor muscles were injected with HRP. We found that during hibernation no axonal transport across the site of crush was seen even after 3 months and that regeneration of the nerve during this period was minimal. Evidence of slight regeneration seen at 90 days could be due to periods of awaking of the animals during their natural hibernation cycle. In these animals HRP deposits were seen only in the nerve distal to crush, i.e., between crush site and muscle. In the nonhibernating squirrels, axoplasmic flow was reestablished at the site of injury as early as 2 weeks after crush, and HRP could be detected in the spinal cord in motoneurons of the ipsilateral ventral horn at spinal levels L3 to L5. In one hibernating animal the peroneal nerve was crushed at the distal site (SNS) and also the spinal cord was injured by dropping a weight. After nerve crush and the spinal cord injury the hibernating state could not be maintained and the animal stayed awake 22 days. The time course of regeneration of the nerve in that animal was similar to that seen in nonhibernating squirrels. After nerve crush in nonhibernating animals, reaction product was also found in sensory cell bodies of dorsal root ganglia as well as in terminals in the substantia gelatinosa of the spinal cord at the same levels. Thus, the axonal transport occurs in hibernating and non-hibernating squirrels in both sensory and motor nerve fibers. The extensor muscle fibers of the hibernating squirrels showed substantial membrane depolarization 90 days after crush. Action potentials from these fibers could be obtained from 15 to 35 days only through stimulating the nerve segment distal to the crush. Stimulation of the proximal nerve segment did not evoke muscle activity. These results demonstrate that nerve regeneration was nearly abolished during hibernation and that blockade of axonal transport continued across a region of nerve crush for the duration of the hibernating period.
利用辣根过氧化物酶（HRP）的逆行运输来确定在冬眠和非冬眠地松鼠中，腓总神经在距其进入伸肌处10至12毫米（SNS）处被挤压，或坐骨神经在距其进入伸肌处33至35毫米（LNS）处被挤压后，腓总神经和坐骨神经的轴突运输状态。还研究了近端神经段重新建立轴突连续性并因此恢复神经肌肉传递的能力。在神经挤压后2周3个月，向伸肌注射HRP。我们发现，在冬眠期间，即使3个月后也未观察到轴突运输穿过挤压部位，并且在此期间神经的再生极少。在90天时观察到的轻微再生迹象可能是由于动物在其自然冬眠周期中的觉醒期。在这些动物中，HRP沉积物仅在挤压部位远端的神经中可见，即在挤压部位与肌肉之间。在非冬眠地松鼠中，早在挤压后2周，损伤部位就重新建立了轴浆流动，并且在脊髓L3至L5节段同侧腹角的运动神经元中可检测到HRP。在一只冬眠动物中，腓总神经在远端部位（SNS）被挤压，并且脊髓因重物掉落而受损。在神经挤压和脊髓损伤后，冬眠状态无法维持，该动物保持清醒22天。该动物中神经再生的时间进程与在非冬眠地松鼠中观察到的相似。在非冬眠动物中神经挤压后，在背根神经节的感觉细胞体以及相同节段脊髓胶状质的终末中也发现了反应产物。因此，轴突运输在冬眠和非冬眠地松鼠的感觉和运动神经纤维中均会发生。冬眠地松鼠的伸肌纤维在挤压90天后显示出大量膜去极化。仅通过刺激挤压部位远端的神经段，才能在15至35天从这些纤维获得动作电位。刺激近端神经段不会引起肌肉活动。这些结果表明，在冬眠期间神经再生几乎被消除，并且在冬眠期持续期间，轴突运输的阻断在神经挤压区域持续存在。
