Extracellular potentials recording in intact taste epithelium by microelectrode array for a taste sensor

Taste receptor cells in taste buds can generate action potentials in response to taste stimuli. The spatiotemporal patterns of the potentials have great value in both biomedical and engineering researches. In the present study, by fixing the biological epithelium onto the surface of microelectrode arrays (MEA), we established a novel taste sensor to record action potentials from the taste receptor cells of rat in response to taste stimuli. By this multi-channel recording method, we examined the electrophysiological activities of taste receptor cells in taste buds to stimuli representing the basic taste qualities (sour, salt, bitter, sweet and umami). The recorded action potentials corresponding to five tastes displayed different spatiotemporal patterns. The multi-channel results demonstrated that taste buds released the spontaneous signals simultaneously and displayed different responses to different tastes stimulations. The temporal characteristics were derived by time-domain and frequency-domain analysis, and the signals fired in different stimuli could be distinguished into different clusters by principal component analysis (PCA). The study provides an effective and reliable platform to recognize and distinguish basic taste qualities.