Glicksman M A, Sanes J R
J Neurocytol. 1983 Aug;12(4):661-71. doi: 10.1007/BF01181529.
During reinnervation of frog skeletal muscle, axons form functional nerve terminals at original synaptic sites on denervated myofibres. When muscle is damaged as well as denervated, myofibres decompose but their sheaths of basal lamina (BL) survive. Despite the absence of myofibres, axons regenerate to contact BL and there acquire clusters of synaptic vesicles and membrane-associated dense patches that resemble active zones; BL regulates this differentiation. We show here that these BL-associated axonal segments appear smaller and contain fewer active zones than terminals on intact myofibres in the same preparation. However, terminals formed on BL sheaths are capable of activity-dependent recycling of synaptic vesicles (demonstrated by tracer uptake), and bear an antigen normally present in terminals but not preterminal axons (demonstrated by immunofluorescence). Thus, axons can acquire functional and biochemical, as well as morphological, characteristics of normal motor nerve terminals in the absence of a postsynaptic cell.
在青蛙骨骼肌的神经再支配过程中，轴突在去神经支配的肌纤维原来的突触部位形成功能性神经末梢。当肌肉既受损又失去神经支配时，肌纤维会分解，但其基膜（BL）鞘会留存下来。尽管没有肌纤维，轴突仍会再生以接触基膜，并在那里获得成群的突触小泡和类似于活性区的膜相关致密斑；基膜调节这种分化。我们在此表明，与完整肌纤维上的末梢相比，这些与基膜相关的轴突段看起来更小，且活性区更少。然而，在基膜鞘上形成的末梢能够进行依赖于活动的突触小泡循环利用（通过示踪剂摄取证明），并且带有一种通常存在于末梢而非轴突前体中的抗原（通过免疫荧光证明）。因此，在没有突触后细胞的情况下，轴突能够获得正常运动神经末梢的功能、生化以及形态特征。
