Action potentials in epithelial taste receptor cells induced by mucosal calcium

Chemosensory cells in the taste bud of the tongue of Necturus generate action potentials in response to electrical stimulation through a microelectrode, as recently described by Roper (Science, 220: 1311-1312, 1983). We report that the epithelial receptor cells also respond to 10 mM CaCl2, applied to the mucosal surface, with a depolarization which elicits action potentials when a threshold of -50 mV is reached. Since CaCl2 is one of the taste stimuli in amphibia, the firing of action potentials by chemoreceptor cells may be part of the signal chain in gustatory reception of Ca ions.