Effect of Bitter Substances on a Model Membrane System of Taste Reception

The effect of bitter substances on the self-sustained electric oscillation of a DOPH (dioleyl phosphate)-Millipore membrane was investigated as a model system of taste reception. Caffeine and theobromine, having higher taste thresholds, had slight effect, but quinine, strychnine and nicotine, exhibiting strong bitterness, increased the frequency of the oscillation. The mode of action of bitter substances on the DOPH-Millipore membrane in the non-oscillatory state suggested that they cause the receptor potential by a change in the phase boundary potential. The intensity of action on the electric potential was associated with the threshold values of bitterness.