The alteration of odor-induced c-Fos immunoreactivity in the rat olfactory bulb after olfactory nerve transection

• Published in: Journal of neurology Vol. 250; no. 1; pp. 51 - 54
• Main Authors: KAWAMOTO, Masahiro, TAMURA, Manabu, OHNO, Koji, KAWASAKI, Yoshiaki, MORI, Katsumi, SHIKINA, Takashi, NODA, Kazuhiro, KUBO, Takeshi
• Format: Journal Article
• Language: English
• Published: Berlin Springer 2003; Springer Nature B.V
• Subjects: Animals; Axotomy; Biological and medical sciences; Immunohistochemistry; Injuries of the nervous system and the skull. Diseases due to physical agents; Male; Medical sciences; Neurology; Neurons; Odorants; Odors; Olfactory Bulb - drug effects; Olfactory Bulb - metabolism; Olfactory Nerve - physiology; Olfactory Pathways - metabolism; Olfactory Receptor Neurons - drug effects; Olfactory Receptor Neurons - metabolism; Otolaryngology; Polymerase Chain Reaction; Propionates - pharmacology; Proto-Oncogene Proteins c-fos - drug effects; Proto-Oncogene Proteins c-fos - metabolism; Rats; Rats, Wistar; RNA, Messenger - analysis; Time Factors; Traumas. Diseases due to physical agents; Tyrosine 3-Monooxygenase - metabolism; Immunohistochemistry; Rat; Central nervous system; Olfactory receptor; Tyrosine 3-monooxygenase; Messenger RNA; Evolution; Medulla oblongata; Nervous system diseases; Pathophysiology; Enzyme; Rodentia; Gene expression; Trauma; Section; Pathology; Vertebrata; Mammalia; Cranial nerve disease; Animal; C-Onc gene; Olfactory nerve; Olfaction; Oxidoreductases; Brain (vertebrata)
• ISSN: 0340-5354; 1432-1459
• DOI: 10.1007/s00415-003-0948-9

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.