The variety of taste sensations, including sweet, umami, bitter, sour, and salty, arises from diverse taste cells, each of which expresses specific taste sensor molecules and associated components for downstream signal transduction cascades. Recent years have witnessed major advances in our understanding of the molecular mechanisms underlying transduction of basic tastes in taste buds, including the identification of the bona fide sour sensor H⁺ channel OTOP1, and elucidation of transduction of the amiloride-sensitive component of salty taste (the taste of sodium) and the TAS1R-independent component of sweet taste (the taste of sugar). Studies have also discovered an unconventional chemical synapse termed “channel synapse” which employs an action potential-activated CALHM1/3 ion channel instead of exocytosis of synaptic vesicles as the conduit for neurotransmitter release that links taste cells to afferent neurons. New images of the channel synapse and determinations of the structures of CALHM channels have provided structural and functional insights into this unique synapse. In this review, we discuss the current view of taste transduction and neurotransmission with emphasis on recent advances in the field.

各种味觉，包括甜味、鲜味、苦味、酸味和咸味，来自不同的味觉细胞，每个味觉细胞表达特定的味觉传感器分子和下游信号转导级联的相关成分。近年来，我们对味蕾中基本味道转导的分子机制的理解取得了重大进展，包括真正的酸味传感器 H ^+的鉴定OTOP1 通道，并阐明了阿米洛利敏感的咸味成分（钠的味道）和 TAS1R 非依赖性甜味成分（糖的味道）的转导。研究还发现了一种称为“通道突触”的非常规化学突触，它采用动作电位激活的 CALHM1/3 离子通道而不是突触小泡的胞吐作用作为神经递质释放的管道，将味觉细胞连接到传入神经元。通道突触的新图像和 CALHM 通道结构的确定为这种独特的突触提供了结构和功能上的见解。在这篇综述中，我们讨论了味觉传导和神经传递的当前观点，重点是该领域的最新进展。