Morphological changes of myenteric neurons in the partially obstructed opossum esophagus.

We have previously described a model of partial esophageal obstruction which leads to hypertrophic and degenerative changes in the smooth muscle cells. In the present communication we describe changes occurring in the myenteric plexus including increased thickness, varicosities and irregular angulations of nerve fiber bundles. The perikarya of myenteric neurons in the obstructed esophagus showed elongated mitochondria, dilated cisternae of the endoplasmic reticulum and increased numbers of secondary lysosomes and multimembranous dense bodies. In myenteric axons, there was infiltration of Schwann cell subunit by collagen fibrils.