title: NADPH-diaphorase-positive nerve fibers associated with motor endplates in the rat esophagus: new evidence for co-innervation of striated muscle by enteric neurons.
abstract: NADPH-diaphorase histochemistry was combined with demonstration of acetylcholinesterase and immunocytochemistry for calcitonin gene-related peptide to study esophageal innervation in the rat. Most of the myenteric neurons stained positively for NADPH-diaphorase, as did numerous varicose nerve fibers in the myenteric plexus, among striated muscle fibers, around arterial blood vessels, and in the muscularis mucosae. A majority of motor endplates (as demonstrated by acetylcholinesterase histochemistry or calcitonin gene-related peptide immunocytochemistry) were associated with fine varicose NADPH-diaphorase-positive nerve fibers. Analysis of brainstem nuclei, sensory vagal, spinal, and sympathetic ganglia in normal and neonatally capsaicin-treated rats, and comparison with anterogradely labeled vagal branchiomotor, preganglionic and sensory fibers led to the conclusion that NADPH-diaphorase-positive fibers on motor endplates originate in esophageal myenteric neurons. No association of NADPH-diaphorase-positive nerve fibers with motor endplates was found in other organs containing striated muscle. These results suggest extensive, presumably nitrergic, co-innervation of esophageal striated muscle fibers by enteric neurons. Thus, control of peristalsis in the esophagus of the rat may be more complex than hitherto assumed.
authors.affiliation: Institute of Anatomy, University of Zürich, Switzerland.
authors.forename: W L
authors.initials: WL
authors.lastname: Neuhuber
authors.forename: J
authors.initials: J
authors.lastname: Wörl
authors.forename: H R
authors.initials: HR
authors.lastname: Berthoud
authors.forename: B
authors.initials: B
authors.lastname: Conte
mesh_terms: D000110:Acetylcholinesterase / Q000032:analysis; D000818:Animals; D001933:Brain Stem / Q000737:chemistry / Q000201:enzymology; D015740:Calcitonin Gene-Related Peptide / Q000032:analysis; D002211:Capsaicin / Q000494:pharmacology; D004947:Esophagus / Q000294:innervation* / Q000502:physiology; D005260:Female; D017950:Ganglia, Sensory / Q000737:chemistry / Q000201:enzymology; D005728:Ganglia, Sympathetic / Q000737:chemistry / Q000201:enzymology; D007150:Immunohistochemistry; D007421:Intestine, Small / Q000294:innervation*; D009045:Motor Endplate / Q000737:chemistry / Q000201:enzymology*; D009130:Muscle, Smooth / Q000294:innervation*; D009252:NADPH Dehydrogenase / Q000032:analysis*; D009412:Nerve Fibers / Q000737:chemistry / Q000201:enzymology*; D009474:Neurons / Q000737:chemistry / Q000201:enzymology*; D051381:Rats; D017208:Rats, Wistar
chemical_list: D009252:NADPH Dehydrogenase; D000110:Acetylcholinesterase; D015740:Calcitonin Gene-Related Peptide; D002211:Capsaicin