Induction of nitric oxide synthase activity in nucleus ambiguus motoneurons after injury to the rat recurrent laryngeal nerve.
Recent studies have implicated nitric oxide (NO) in neuronal degeneration and plasticity in the motor nervous system. In the present study, we investigated the induction of nitric oxide synthase (NOS) in the motoneurons in the nucleus ambiguus (NA) after injury to the rat recurrent laryngeal nerve (RLN) using nicotinamide-adenine-dinucleotide-phosphate-diaphorase (NADPH-d) histochemistry. NADPH-d reactivity was clearly induced in motoneurons in the ipsilateral NA after transection or avulsion of the RLN, compared with control animals. This finding suggests that NO may play an important role in the pathogenesis of RLN paralysis. Another interesting finding in the present study was the induction of NADPH-d reactivity in nerve terminals of the NA after RLN injury. This finding suggests that RLN injury has some effect on nitrergic input to the NA and a direct effect on the motoneurons.
Bamba
H
H
Department of Otolaryngology, Kyoto Prefectural University of Medicine, Japan.
Uno
T
T
Koike
S
S
Shogaki
K
K
Hisa
Y
Y
D000818:Animals; D001933:Brain Stem / Q000201:enzymology* / Q000473:pathology; D004790:Enzyme Induction / Q000502:physiology; D008297:Male; D009046:Motor Neurons / Q000201:enzymology* / Q000473:pathology; D009252:NADPH Dehydrogenase / Q000378:metabolism; D009410:Nerve Degeneration / Q000201:enzymology* / Q000473:pathology; D009411:Nerve Endings / Q000201:enzymology / Q000473:pathology; D009473:Neuronal Plasticity / Q000502:physiology; D019001:Nitric Oxide Synthase / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012009:Recurrent Laryngeal Nerve / Q000473:pathology; D061226:Recurrent Laryngeal Nerve Injuries
D019001:Nitric Oxide Synthase; D009252:NADPH Dehydrogenase