Neuro-muscular junctions of longitudinal and circular muscle fibers of the guinea-pig esophagus and their relation to myenteric plexus.
The structure of the neuromuscular junctions (NMJs) and their relation to the myenteric plexus were studied by zinc iodide-osmic acid (ZIO) staining and by scanning electron microscopy in the guinea-pig esophagus. The esophageal muscle coat consisted of the inner circular and outer longitudinal striated muscle fibers. The myenteric plexus was located between the two muscle layers along its whole length and was characterized by a loose and irregular network. It was demonstrated that unmyelinated nerve fibers form NMJs with the muscle fibers of both layers. The NMJs in the longitudinal muscle can be classified as 'plate' type, whereas those of the circular muscle resemble the 'grape' type. The different NMJs in the two muscle layers probably correspond to different contractile properties. The whole-mount preparations with ZIO staining also demonstrated that some NMJs receive minute branches from the myenteric plexus. Therefore, it is likely that the myenteric plexus is involved in the control of striated muscles of the guinea-pig esophagus.
Zhou
D S
DS
Department of Basic Human Sciences, School of Human Sciences, Waseda University, Saitama, Japan.
Desaki
J
J
Komuro
T
T
D000818:Animals; D004947:Esophagus / Q000648:ultrastructure*; D005260:Female; D006168:Guinea Pigs; D008297:Male; D008854:Microscopy, Electron; D008855:Microscopy, Electron, Scanning; D018485:Muscle Fibers, Skeletal / Q000648:ultrastructure*; D018482:Muscle, Skeletal / Q000166:cytology / Q000648:ultrastructure; D009197:Myenteric Plexus / Q000648:ultrastructure*; D009469:Neuromuscular Junction / Q000648:ultrastructure*