Growth associated protein-43 mRNA expression in nucleus ambiguus motoneurons after recurrent laryngeal nerve injury in the rat.
OBJECTIVE
To investigate the time-dependent differences in growth associated protein-43 (GAP-43) mRNA expression in the nucleus ambiguus (NA) motoneurons after recurrent laryngeal nerve (RLN) transection in the rat.


METHODS
Animals were sacrificed on Days 1, 7, 14 and 21 after axotomy. The sections were then processed for in situ hybridization of GAP-43 mRNA.


RESULTS
GAP-43 mRNA transiently increased after axotomy, reaching a peak on postoperative Day 7, and then decreased gradually at 14 and 21 days after axotomy. The peak period of GAP-43 expression in the NA is different from those in the facial and hypoglossal nuclei after axotomy.


CONCLUSIONS
We have already reported that neuronal nitric oxide synthase (nNOS) is induced in the NA motoneurons after axotomy and reaches a peak on postoperative Day 14. This study shows that the expressions of GAP-43 and nNOS are chronologically different.
Uno
Toshiyuki
T
Department of Otolaryngology, Kyoto Prefectural University of Medicine, Kyoto, Japan.
Shogaki
Kazuhiro
K
Bamba
Hitoshi
H
Koike
Shinobu
S
Naruse
Yoshihisa
Y
Ijima
Norio
N
Tanaka
Masaki
M
Hisa
Yasuo
Y
D000818:Animals; D019771:Axotomy; D001483:Base Sequence; D004195:Disease Models, Animal; D019922:GAP-43 Protein / Q000235:genetics*; D005786:Gene Expression Regulation; D017403:In Situ Hybridization; D008297:Male; D008526:Medulla Oblongata / Q000378:metabolism*; D008969:Molecular Sequence Data; D009046:Motor Neurons / Q000378:metabolism*; D009416:Nerve Regeneration / Q000235:genetics*; D019001:Nitric Oxide Synthase / Q000378:metabolism*; D010525:Peripheral Nerves; D016133:Polymerase Chain Reaction; D012333:RNA, Messenger / Q000032:analysis*; D011897:Random Allocation; D051381:Rats; D017207:Rats, Sprague-Dawley; D061226:Recurrent Laryngeal Nerve Injuries; D012016:Reference Values; D012680:Sensitivity and Specificity
D019922:GAP-43 Protein; D012333:RNA, Messenger; D019001:Nitric Oxide Synthase