ODOR RESPONSES AFTER COMPLETE DESENSITIZATION OF THE CAMP-DEPENDENT PATHWAY IN TURTLE OLFACTORY CELLS

The degree of contribution of the cAMP signal transduction pathway to odor responses was examined by recording current responses from isolat ed turtle olfactory cells under the whole-cell voltage clamp condition s. The cAMP signal transduction pathway was desensitized by dialyzing 1 mM cAMP and 0.5 mM IBMX from the patch pipette into the cells. Extra cellular application of 3 mM cpt-cAMP, a membrane-permeable cAMP analo gue elicited no response, indicating that the cAMP pathway was complet ely desensitized. Application of an odorant cocktail induced a large i nward current under these conditions, suggesting that the cAMP-indepen dent signal transduction contributes significantly to generation of od or responses in the turtle.