The ultrastructure of Auerbach's plexus in the guinea-pig. II. Non-neuronal elements.

The ultrastructural features of non-neuronal cells associated with Auerbach's plexus in the stomach, ileum and colon of the guinea-pig have been examined. Apart from Schwann, mast and interstitial or fibroblast-like cells, two other cell types are described that do not appear to have been reported previously. Of these two cell types, one was found external, but close to, the plexus and contained large granular vesicles. The other cell type contained numerous glycogen-like granules, was situated close to or within axon bundles and had processes that extended within and peripheral to nerve bundles as well as being close to smooth muscle cells. Although axon varicosities were opposed to both the processes and cell body of the second type of cell, synaptic-like contacts were not observed.