摘要
Taste receptors on the tongue discriminate between five fundamental tastes:sour,sweet,bitter,salty,and umami(Chandrashekar et al.,2006).Typically,stimuli that evoke bitterness and acidity prompt aversive responses by animals,whereas sweet and umami flavors are appetitive and enjoyable.Saltiness is unique in that it transitions from an appetitive to an aversive stimulus with increasing concentrations.