title: Forskolin enhanced off-response in the turtle olfactory system.
abstract: Olfactory responses appear not only at the onset of odor stimulation, but also at the termination of the stimulation. It is widely considered that the cAMP-pathway is involved in the generation of odor responses. We examined how cAMP affects the generation of off-responses. To explore the role of the cAMP-pathway, odorants were applied to the turtle olfactory epithelium after forskolin at high concentrations which saturated the olfactory response to forskolin. Various odorants induced off-responses after 50 microM forskolin, indicating that off-responses are not induced via the cAMP-dependent pathway. However, the magnitude of the off-response after forskolin varied from 100 to 1400% of those of off-responses in its absence, indicating that forskolin greatly enhanced the off-responses to some odorants. The off-response after 0.1 mM citralva was also enhanced by 3 mM 8-(4-chlorophenylthio)-adenosine 3',5'-cyclic monophosphate (cpt-cAMP). These results suggested that cAMP modulates off-responses in the turtle olfactory system.
authors.affiliation: Faculty of Pharmaceutical Sciences, Hokkaido University, Sapporo, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Kashiwayanagi
authors.forename: H
authors.initials: H
authors.lastname: Kawahara
authors.forename: K
authors.initials: K
authors.lastname: Kurihara
mesh_terms: D015056:1-Methyl-3-isobutylxanthine / Q000494:pharmacology; D000818:Animals; D005576:Colforsin / Q000494:pharmacology*; D000242:Cyclic AMP / Q000031:analogs & derivatives / Q000502:physiology; D015640:Ion Channel Gating / Q000187:drug effects; D009475:Neurons, Afferent / Q000187:drug effects / Q000502:physiology; D009812:Odorants; D009831:Olfactory Mucosa / Q000187:drug effects; D012903:Smell / Q000187:drug effects*; D014426:Turtles / Q000502:physiology*
chemical_list: D005576:Colforsin; D000242:Cyclic AMP; D015056:1-Methyl-3-isobutylxanthine