Differential ion dependence of frog olfactory responses to various odorants.

1. Dependence of the fron olfactory bulbar responses on NaCl concentration greatly varied from odorant to odorant. The responses to odorants such as 1-carvone and isoamyl acetate were essentially unchanged by removal of NaCl, while those to odorant such as citral and beta-ionone were greatly decreased by removal of NaCl. 2. The NaCl requirement for the responses to certain odorants was greatly decreased by an increase in pH or temperature of the stimulating solution. 3. It was concluded that changes in ion permeability at the apical membranes of olfactory cells including olfactory ciliary membranes are not involved in generation of the in vivo olfactory responses to certain odorants.