The alteration of odor-induced c-Fos immunoreactivity in the rat olfactory bulb after olfactory nerve transection.
We used the rats in which one olfactory nerve had been transected and observed the odor (Propionic acid) -induced c-Fos immunoreactivity in the bulb at different times (2, 4, 8 weeks) after nerve transection. The exposure to odor produced a strong cluster of c-Fos positive cells in the mediodorsal region of the intact bulb. On the other hand, the transected bulb showed much less reactivity 2 weeks after neurectomy; however, a large number of positive cells were observed in the whole of the bulb from 4 weeks after neurectomy. Furthermore, we measured the levels of mRNA for tyrosine hydroxylase (TH), which was the marker of odor-induced olfactory nerve activity in the bulb, by using real-time PCR. The level of TH mRNA decreased on the transected side at 2 weeks but recovered to the level of the contralateral side at 4 weeks after neurectomy. We firstly demonstrated that projection mapping of odor receptors was altered after olfactory nerve transection by using an immunohistochemical method.
Kawamoto
Masahiro
M
Department of Otolaryngology and Sensory Organ Surgery (E8), Osaka University School of Medicine, 2-2 Yamadaoka, Suita-City, Osaka 5650871, Japan.
Tamura
Manabu
M
Ohno
Koji
K
Kawasaki
Yoshiaki
Y
Mori
Katsumi
K
Shikina
Takashi
T
Noda
Kazuhiro
K
Kubo
Takeshi
T
D000818:Animals; D019771:Axotomy; D007150:Immunohistochemistry; D008297:Male; D009812:Odorants; D009830:Olfactory Bulb / Q000187:drug effects / Q000378:metabolism*; D009832:Olfactory Nerve / Q000502:physiology; D009833:Olfactory Pathways / Q000378:metabolism; D018034:Olfactory Receptor Neurons / Q000187:drug effects / Q000378:metabolism*; D016133:Polymerase Chain Reaction; D011422:Propionates / Q000494:pharmacology; D016760:Proto-Oncogene Proteins c-fos / Q000187:drug effects / Q000378:metabolism*; D012333:RNA, Messenger / Q000032:analysis; D051381:Rats; D017208:Rats, Wistar; D013997:Time Factors; D014446:Tyrosine 3-Monooxygenase / Q000378:metabolism
D011422:Propionates; D016760:Proto-Oncogene Proteins c-fos; D012333:RNA, Messenger; D014446:Tyrosine 3-Monooxygenase; C029658:propionic acid