The myenteric plexus of the rat colon: a methodological approach for scanning electron microscopical study

In the present research four different procedures were tested for the Scanning Electron Microscopic identification of Auerbach's myenteric plexus in the distal colon of the rat. The specimens were processed as follows: enzymatic and chemical digestion (trypsin and HCl); fixation with glutaraldehyde; fixation and staining with zinc iodide/osmium tetroxide (ZIO); fixation and staining with zinc iodide/osmium tetroxide (ZIO) followed by maceration in NaOH solution. All the procedures required microdissection to separate the different layers of the colonic wall. Light microscopic controls were prepared with the ZIO technique. Among the methods utilized, fixation and staining with ZIO appeared to be by far the best as regards the preservation of the architectural arrangement of the myenteric plexus as well as of the fine structural details.