Coupling and innervation patterns of interstitial cells of Cajal in the deep muscular plexus of the guinea-pig.
Interstitial cells in the deep muscular plexus (ICC-DMP) are thought to be essential for neurotransmission in the circular muscle. There is evidence for gap junctions within the ICC-DMP network and between ICC-DMP and muscle cells; however, there is no evidence for functional coupling via these gap junctions. In addition, the innervation of individual ICC-DMP has not been studied. We investigated these questions by injecting the dye Lucifer yellow into ICC-DMP of guinea-pig ileum. Nerves were labelled immunohistochemically for protein gene product 9.5. Cells were imaged by confocal microscopy. Most (79%) of the dye-injected ICC-DMP were coupled to one to five other ICC-DMP, and 86% of them were coupled to one to five circular muscle cells. Octanol effectively blocked all coupling. Incubation in pH 6.8-7.0 reduced ICC-ICC coupling to 49% and ICC-muscle coupling to 32%. In contrast, pH 7.8-7.9 increased ICC-ICC and ICC-muscle coupling to 100%. Most ICC somata (95%) and processes (60%) were in close proximity with both nerve fibres and smooth muscle cells. These results provide direct evidence for functional coupling within the ICC-DMP network, and between this network and cells of the outer circular muscle layer and showed that coupling can be affected by pH.
Kobilo
T
T
Laboratory of Experimental Surgery, Hadassah University Hospital Mount Scopus and Hebrew University Hadassah Medical School, Jerusalem, Israel.
Szurszewski
J H
JH
Farrugia
G
G
Hanani
M
M
D000818:Animals; D003239:Connective Tissue Cells / Q000737:chemistry / Q000502:physiology*; D006168:Guinea Pigs; D007082:Ileum / Q000737:chemistry / Q000294:innervation* / Q000502:physiology*; D008297:Male; D009197:Myenteric Plexus / Q000737:chemistry / Q000502:physiology; D032389:Myocytes, Smooth Muscle / Q000737:chemistry / Q000502:physiology; D009412:Nerve Fibers / Q000737:chemistry / Q000502:physiology; D009415:Nerve Net / Q000737:chemistry / Q000502:physiology