Neuroblastoma cell as model for olfactory cell: mechanism of depolarization in response to various odorants

The mouse neuroblastoma cell (N-18 clone) was used as a model for an olfactory cell. The N-18 cell was found to be depolarized reversibly by various species of odorants. The minimum concentrations of odorants which induced depolarization (threshold concentration) varied greatly with the species of odorants. There was a good correlation between the order of the threshold concentrations for various odorants in the N-18 cell and that in the frog olfactory responses. Replacement of Na+ and Cl- with impermeable ions or reduction of calcium concentration from 1.8 mM to 0.1 mM had practically no effect on the magnitude of the depolarization response to odorants. The input membrane resistance was little changed during the depolarization induced by various odorants. No reversal potential was observed when the cell was depolarized by n-amyl acetate or vanillin. It is suggested that the depolarization of N-18 cell by odorants is induced by changes in the phase-boundary potential at the outer surface of the cell.