Salt and sour taste are perceived by?

The salty taste is triggered by NaCl. Salt-sensitive taste is mediated by a Na+-selective channel known as ENaC, the amiloride-sensitive epithelial sodium channel. The entry of Na+ into the salt receptors depolarizes the membrane, generating the receptor potential. In humans, the amiloride sensitivity of salt taste is less pronounced than in some species suggesting that there are additional mechanisms to activate salt-sensitive receptors. The sour taste is triggered by protons (H+ ions). ENaCs permit the entry of protons and may contribute to the sensation of sour taste. The H+ions can also bind to and block a K+-sensitive channel. The fall in K+ permeability can depolarize the membrane. Also, HCN, a hyperpolarization-activated cyclic nucleotide-gated cation channel, and other mechanisms may contribute to sour transduction.Ref: Ganong&;s review of medical physiology 23rd edition Page no: 225