Projection pathways, co-existence of peptides and synaptic organization of nerve fibers in the inferior mesenteric ganglion of the guinea-pig.
The presence of immunoreactive enkephalin, dynorphin, vasoactive intestinal polypeptide, cholecystokinin, substance P and neuropeptide Y in nerve fibers that project to the guinea-pig inferior mesenteric ganglion was analysed, after different denervation and ligation procedures. A quantitative analysis demonstrates that enkephalin- and substance P fibers reach the ganglion mainly via lumbar splanchnic and partly via intermesenteric nerves. Dynorphin-, vasoactive intestinal polypeptide- and cholecystokinin fibers reach the ganglion mainly via colonic and partly via hypogastric or intermesenteric nerves. Neuropeptide Y fibers enter via intermesenteric, lumbar splanchnic and hypogastric nerves and pass through the ganglion. Analysis of serial 0.5 micron sections tends to confirm co-existence: of dynorphin, vasoactive intestinal polypeptide and cholecystokinin in fibers projecting from the colon; of dynorphin with substance P in the lumbar splanchnic nerves; and of neuropeptide Y with substance P in the hypogastric and colonic fibers. Synaptic contacts, predominantly axodendritic, onto the ganglion cells from enkephalin-, vasoactive intestinal polypeptide-, and substance P-containing terminals were revealed by electron microscopy. Enkephalin-immunoreactive axon varicosities are filled with small, clear vesicles with a few large, cored vesicles and form asymmetric synapses; dynorphin-, vasoactive intestinal polypeptide- and cholecystokinin-immunoreactive axon varicosities are rich in large, dense-cored vesicles and form symmetric synapses.
Masuko
S
S
Department of Anatomy, Saga Medical School, Japan.
Chiba
T
T
D000818:Animals; D001839:Bombesin / Q000032:analysis; D002766:Cholecystokinin / Q000032:analysis; D004399:Dynorphins / Q000032:analysis; D004745:Enkephalins / Q000032:analysis; D005728:Ganglia, Sympathetic / Q000032:analysis / Q000648:ultrastructure*; D006168:Guinea Pigs; D007150:Immunohistochemistry; D008297:Male; D008854:Microscopy, Electron; D009412:Nerve Fibers / Q000032:analysis / Q000648:ultrastructure*; D009478:Neuropeptide Y / Q000032:analysis; D010455:Peptides / Q000032:analysis*; D013373:Substance P / Q000032:analysis; D013569:Synapses / Q000032:analysis / Q000648:ultrastructure*; D014660:Vasoactive Intestinal Peptide / Q000032:analysis
D004745:Enkephalins; D009478:Neuropeptide Y; D010455:Peptides; D013373:Substance P; D014660:Vasoactive Intestinal Peptide; D004399:Dynorphins; D002766:Cholecystokinin; D001839:Bombesin