Preneural phase of taste.

The preneural phase of taste has been studied, describing first the pit region of taste buds and its dynamics. The biochemical regulation of the preneural phase is then analyzed, with emphasis on thiol and metal (certain metals) interactions: the first inhibit and the second facilitate. The equilibrium between thiol and metal ions regulates the flux of tastants, probably at the level of the microvilli membrane. The hypothetical role of the pore and dense substance is considered.