Evaluation of the T&T olfactometer by mapping c-fos protein in an olfactory bulb.
OBJECTIVE
Although in Japan the T&T olfactometer is most commonly used in patients suffering from smelling disorders, no scientific analysis has been performed so far. The objective of this study was to clarify whether the five odorants used in the T&T olfactometer are suitable or not. We mapped the glomeruli activated by the five test odorants employed in the T&T olfactometer. The expression of c-fos protein as a marker of neuronal excitation was monitored using an immunohistochemical technique.


METHODS
The expression of c-fos protein in the rat olfactory bulb was investigated to determine what part of the olfactory system is activated by five odorants used in the T&T olfactometer.


METHODS
Each rat was isolated in a clean cage for 120 min to reduce the basal expression of c-fos protein. Each rat was fixed in the cage and exposed to one of five test odorants for 90 min. The expression of c-fos protein was measured using an immunohistochemical technique.


RESULTS
Each odorant activated numerous glomeruli and the patterns of distribution of activated glomeruli were specific to each odorant. Glomeruli in most regions of the bulb were activated by all five test odorants.


CONCLUSIONS
We assume that in the T&T olfactometer the optimal ((five)) odorants are employed, because the glomeruli activated by those odorants showed unique patterns in the immunohistochemical assay.
Kawamoto
M
M
Department of Otolaryngology and Sensory Organ Surgery (E8), Osaka University Graduate School of Medicine, Osaka, Japan.
Ohno
K
K
Tamura
M
M
Kawasaki
Y
Y
Kubo
T
T
D000818:Animals; D015415:Biomarkers; D004864:Equipment and Supplies / Q000592:standards*; D007150:Immunohistochemistry; D008297:Male; D009812:Odorants; D009830:Olfactory Bulb / Q000378:metabolism*; D010036:Otolaryngology / Q000295:instrumentation*; D025941:Protein Interaction Mapping; D016760:Proto-Oncogene Proteins c-fos / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar; D013268:Stimulation, Chemical
D015415:Biomarkers; D016760:Proto-Oncogene Proteins c-fos