Figure 6. Modulatory effect of MDR inhibitors on the olfactory response to odorants in rat and mouse.

A: Representative superimposed electroolfactogram traces recorded in the septal olfactory mucosa of a rat (left) and a mouse (right) under control conditions. Responses are recorded to a sequence of stimuli (inset, left) as KCl, IBMX, a mixture of odorants, isoamyl acetate and 2,5-dimethyl pyrazine, at concentrations of 10⁻⁴ M. B: Representative selection of EOG recordings from rats in response to the mixture at a concentration of 10⁻⁴ M before (control, solid line), during (inhibitor, dashed line), and after (recovery, dot-dash line) application of four MDR inhibitors: verapamil at 200 µM, cyclosporin A (CsA) at 5 µM, probenecid at 2.5 mM and MK571 at 25 µM. Recordings are from four different specimen.