Velez, ZéliaHubbard, PeterBarata, E. N.Canario, Adelino V. M.2014-05-122014-05-122013Velez, Z.; Hubbard, P. C.; Barata, E. N.; Canário, A. V. M. Olfactory transduction pathways in the Senegalese sole Solea senegalensis , Journal of Fish Biology, 83, 3, 501-514, 2013.0022-1112AUT: ACA00258;http://hdl.handle.net/10400.1/3858This study tested whether differences in sensitivity between the upper and lower olfactory epithelia of Solea senegalensis are associated with different odorant receptors and transduction pathways, using the electro-olfactogram. Receptor mechanisms were assessed by cross-adaptation with amino acids (L-cysteine, L-phenylalanine and 1-methyl-L-tryptophan) and bile acids (taurocholic acid and cholic acid). This suggested that relatively specific receptors exist for 1-methyl-L-tryptophan and Lphenylalanine (food-related odorants) in the lower epithelium, and for taurocholic acid (conspecificderived odorant) in the upper. Inhibition by U73122 [a phospholipase C (PLC) inhibitor] suggested that olfactory responses to amino acids were mediated mostly, but not entirely, by PLC-mediated transduction (IC50; 15–55 nM), whereas bile acid responses were mediated by both PLC and adenylate cyclase–cyclic adenosine monophosphate (AC–cAMP) (using SQ-22536; an AC inhibitor). Simultaneous application of both drugs rarely inhibited responses completely, suggesting possible involvement of non-PLC and non-AC mediated mechanisms. For aromatic amino acids and bile acids, there were differences in the contribution of each transduction pathway (PLC, AC and non-PLC and non-AC) between the two epithelia. These results suggest that differences in sensitivity of the two epithelia are associated with differences in odorant receptors and transduction mechanisms.engAdenylate cyclasePhospholipase CElectro-olfactogramBile acidAsymmetryAmino acidjournal article2014-05-08http://dx.doi.org/10.1111/jfb.12185