Nonvagal origin of galanin-containing nerve terminals innervating striated muscle fibers of the rat esophagus.
We investigated the origin of galanin-positive nerve fibers on motor endplates in rat esophagus using anterograde 1,1'-dioleyl-3,3,3', 3'-tetramethylindocarbocyanine methane sulfonate (DiI) tracing from the nucleus ambiguus combined with galanin immunocytochemistry and calcitonin gene-related peptide immunocytochemistry. To demonstrate spatial relationships of galanin-positive nerve fibers to vagal and enteric nerve fibers on motor endplates, we combined galanin immunocytochemistry with calcitonin gene-related peptide immunostaining for labeling of vagal terminals, and vasoactive intestinal peptide immunoreactivity and NADPH-diaphorase histochemistry for demonstration of enteric nerve fibers. Within fine varicose nerve fibers, galanin was colocalized with vasoactive intestinal peptide and NADPH-diaphorase to a high degree and turned out to be completely separated from calcitonin gene-related peptide-positive or anterogradely DiI-labeled vagal motor terminals. These results indicate that the enteric nervous system is the most important and possibly the only source of galanin-positive nerve terminals on motor endplates in rat esophagus. Galanin may be, in addition to nitric oxide and vasoactive intestinal peptide, a mediator of the enteric coinnervation of striated muscle in this organ.
Wörl
J
J
Anatomy Institute, University of Erlangen-Nürnberg, Krankenhausstrasse 9, D-91054 Erlangen, Germany.
Fischer
J
J
Neuhuber
W L
WL
D000818:Animals; D015415:Biomarkers; D001923:Brain Chemistry; D001933:Brain Stem / Q000737:chemistry / Q000166:cytology; D002038:Bungarotoxins; D015740:Calcitonin Gene-Related Peptide / Q000032:analysis; D002232:Carbocyanines; D017615:Enteric Nervous System / Q000737:chemistry / Q000166:cytology; D004947:Esophagus / Q000166:cytology / Q000294:innervation*; D005260:Female; D016650:Fluorescein-5-isothiocyanate; D005456:Fluorescent Dyes; D019004:Galanin / Q000032:analysis*; D008297:Male; D009045:Motor Endplate / Q000737:chemistry / Q000201:enzymology; D018485:Muscle Fibers, Skeletal / Q000166:cytology / Q000502:physiology; D018482:Muscle, Skeletal / Q000166:cytology / Q000294:innervation*; D009252:NADPH Dehydrogenase / Q000032:analysis; D009411:Nerve Endings / Q000737:chemistry* / Q000201:enzymology; D051381:Rats; D017208:Rats, Wistar; D011978:Receptors, Nicotinic / Q000032:analysis; D014630:Vagus Nerve / Q000737:chemistry / Q000166:cytology*; D014660:Vasoactive Intestinal Peptide / Q000032:analysis
D015415:Biomarkers; D002038:Bungarotoxins; C101089:CM-DiI; D002232:Carbocyanines; D005456:Fluorescent Dyes; D011978:Receptors, Nicotinic; D014660:Vasoactive Intestinal Peptide; D019004:Galanin; D009252:NADPH Dehydrogenase; D016650:Fluorescein-5-isothiocyanate; D015740:Calcitonin Gene-Related Peptide