A Selective Pmca Inhibitor Does Not Prolong The Electroolfactogram In Mouse

Background: Within the cilia of vertebrate olfactory receptor neurons, Ca2+ accumulates during odor transduction. Termination of the odor response requires removal of this Ca2+, and prior evidence suggests that both Na+/Ca2+ exchange and plasma membrane Ca2+-ATPase (PMCA) contribute to this removal.Principal Findings: In intact mouse olfactory epithelium, we measured the time course of termination of the odor-induced field potential. Replacement of mucosal Na+ with Li+, which reduces the ability of Na+/Ca2+ exchange to expel Ca2+, prolonged the termination as expected. However, treating the epithelium with the specific PMCA inhibitor caloxin 1b1 caused no significant increase in the time course of response termination.Conclusions: Under these experimental conditions, PMCA does not contribute detectably to the termination of the odor response.