The microphysiology of peripheral taste organs

Recent studies on how peripheral taste organs function have revealed a number of intriguing membrane mechanisms underlying taste transduction. The story is still evolving, but certain generalities can now be stated confidently. For example, there is no one single chemosensory membrane transduction event. Instead, the different taste qualities-sweet, sour, salty, bitter-are subserved by different mechanisms. Furthermore, chemical and electrical synaptic processing in the taste bud is likely to modulate the output of the taste organs and may contribute to how different taste qualities are discriminated. Synapses occur between adjacent cells in the taste organ as well as between receptor cells and sensory fibers. The preponderance of data indicates that biogenic amines are present in taste buds and exert some form of neuromodulatory control, if not frank neurotransmission, in peripheral taste organs. Current research in the microphysiology of taste buds includes extending and refining our understanding of how the apical, chemosensitive regions of receptor cells respond to taste stimuli, identifying what synaptic transmitters exist in taste organs, and exploring synaptic mechanisms in taste buds.