Role of divalent cations in EOG generation

Underwater EOGs in response to 10^–4 M isoamyl acetatewere recorded in vivo in frogs. The olfactory mucosa was superfusedby sodium-free sucrose solutions, and the effect of the additionof millimolar concentrations of sodium, calcium, cobalt, bariumor cadmium was studied. All voltage responses were standardizedaccording to the solution resistivities. Barium and calciumefficiently restored the response; sodium and cobalt were lessefficient. Cobalt did not alter the restoring effect of calcium.Cadmium induced an irreversible blockage irrespective of thepresence of calcium. These results are discussed in terms ofpossible ionic mechanisms mediating olfactory responses.