Involvement of the calcium channel beta3 subunit in olfactory signal transduction.
Despite the expression of voltage-dependent Ca2+ channels in nasal turbinate epithelium, their role in odorant chemosensation has remained obscure. Therefore, we investigated olfactory neurotransduction in beta3-deficient mice. RT-PCR and Western blots confirmed the expression of various types of Ca2+ channels in the nasal turbinate. Electrophysiological evaluations revealed that beta3-null mice had a 60% reduction in the high-voltage-dependent Ca2+ currents in olfactory receptor neurons due to reduced N- and L-type channel currents. The beta3-null mice showed increased olfactory neuronal activity to triethylamine, and this effect was mimicked by the perfusion of the specific N-type Ca2+ channel inhibitor omega-conotoxin GVIA in the electro-olfactogram. Diluted male urine odors induced higher Fos immunoreactivity in the main olfactory bulbs of beta3-deficient mice, indicating enhanced signal transduction of odor information in these mice. Our data indicate the involvement of voltage-dependent Ca2+ channels and importance of the beta3 subunit in olfactory signal transduction.
Shiraiwa
Takeshi
T
Graduate School of Pharmaceutical Sciences, Hokkaido University, Sapporo, Japan.
Kashiwayanagi
Makoto
M
Iijima
Toshihiko
T
Murakami
Manabu
M
D000818:Animals; D015220:Calcium Channels / Q000172:deficiency / Q000235:genetics / Q000378:metabolism*; D008297:Male; D051379:Mice; D018345:Mice, Knockout; D009812:Odorants; D009830:Olfactory Bulb / Q000378:metabolism*; D021122:Protein Subunits / Q000172:deficiency / Q000235:genetics / Q000378:metabolism; D016760:Proto-Oncogene Proteins c-fos / Q000276:immunology / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics; D015398:Signal Transduction; D014158:Transcription, Genetic / Q000235:genetics; D014420:Turbinates / Q000378:metabolism
D015220:Calcium Channels; D021122:Protein Subunits; D016760:Proto-Oncogene Proteins c-fos; D012333:RNA, Messenger