Tremblay J P, Grégoire L, Sasseville R, Guay G, Belhumeur C
Department of Anatomy, Laval University, Quebec, Canada.
Synapse. 1988;2(2):148-56. doi: 10.1002/syn.890020206.
A total of 769 neuromuscular junction profiles (on 221 muscle fibers) from 21 normal (C57BL/6J +/+), 6 heterozygous (C57BL/6J dy2J/+) and 22 homozygous dystrophic (C57BL/6J dy2J/dy2J) gastrocnemius were photographed in electron microscopy. The fast and slow twitch muscle fibers were differentiated by the width of the Z lines. The number of secondary postjunctional folds per unit length of synaptic cleft was lower in dystrophic than in normal animals. Intermediate values were obtained in heterozygous animals. The length of the postsynaptic membrane was measured and normalized by dividing it by the length of the cross-section through the synaptic cleft. This normalized length of postjunctional membrane was significantly reduced by 45% in dystrophic animals relative to normal animals and by 41% relative to heterozygous animals. The depth of the secondary folds was also significantly reduced in dystrophic animals relative to normal animals in both fast and slow twitch fibers. These morphometric changes of the postjunctional membrane were observed on NMJs whose nerve terminals were not significantly modified by the dystrophic process and were sometimes observed on apparently normal muscle fibers.
对来自21只正常（C57BL/6J +/+）、6只杂合（C57BL/6J dy2J/+）和22只纯合营养不良（C57BL/6J dy2J/dy2J）腓肠肌的769个神经肌肉接头轮廓（在221条肌纤维上）进行了电子显微镜拍照。通过Z线的宽度区分快肌纤维和慢肌纤维。营养不良动物突触后膜每单位长度的次级褶皱数量低于正常动物。杂合动物的值介于两者之间。测量突触后膜的长度，并通过将其除以穿过突触间隙的横截面长度进行归一化。与正常动物相比，营养不良动物的突触后膜归一化长度显著减少45%，与杂合动物相比减少41%。在快肌纤维和慢肌纤维中，营养不良动物的次级褶皱深度相对于正常动物也显著降低。在神经末梢未因营养不良过程而显著改变的神经肌肉接头上观察到了突触后膜的这些形态测量变化，有时在看似正常的肌纤维上也观察到了这些变化。
