Structural alterations of the junctional region in extraocular muscle of dystrophic mice. II. Hypertrophy of the neuromuscular junctional apparatus.
The fine structure of end-plate abnormalities was studied in the Bar harbor C57Bl/6jdy2j dystrophic mouse. A marked increase in area and volume of junctional sarcoplasm was often apparent. Such hypertrophied end-plates were often penetrated by networks of axonal terminal branches. At times, pseudopod-like extensions of the junctional sarcoplasm encompassed and made protracted synaptic contact with the incoming axon. Such apparent remodeling of the neuromuscular apparatus might represent a compensatory cellular response to decreased impulse transmission efficiency, as might result from a flattening of the postjunctional folding seen on abnormal muscle fibers in these animals.
D000818:Animals; D001369:Axons / Q000648:ultrastructure; D006984:Hypertrophy; D002479:Inclusion Bodies / Q000648:ultrastructure; D051379:Mice; D008815:Mice, Inbred Strains; D008931:Mitochondria, Muscle / Q000648:ultrastructure; D009045:Motor Endplate / Q000648:ultrastructure; D009136:Muscular Dystrophies / Q000473:pathology*; D009469:Neuromuscular Junction / Q000648:ultrastructure*; D009801:Oculomotor Muscles / Q000648:ultrastructure*