Biosensor recording of extracellular potentials in the taste epithelium for bitter detection

The sense of bitter taste provides critical information about ingestion of toxic and noxious chemicals. In this study, a novel biosensor, mimicking biological responses to bitter compounds, was developed to measure and evaluate bitters. We used 32-channel microelectrode arrays (MEAs) with the diameter of 30 μm as a multi-channel recording platform, and employed intact taste epithelium of rats as a biological sensing element. Electrophysiological activities of epithelium which preserved native state of taste cell population were measured and analyzed through the multirecording system. We found that administrations of different bitter stimuli such as quinine, denatonium and cycloheximide significantly evoked specific responses respectively, and electrophysiological signal characteristics, such as firing rates, amplitudes and power spectrum, have a visible increase with concentrations of bitternesses. The investigation of taste epithelium with cellular potential measurement based on MEAs represents a fast and reliable biosensor for recognizing and distinguishing bitter tastants.