The role of desensitization of ligand-gated channels at fast chemical synapses has been difficult to establish. Desensitization has been studied traditionally with prolonged agonist exposure, whereas the duration of free neurotransmitter in the synaptic cleft is relatively brief. Studies of acetylcholine-, glutamate- and GABA-gated channels using rapid agonist application now provide a means to assess the effects of desensitization in shaping synaptic responses and in influencing neuronal excitability. These data reveal several strikingly different patterns by which the receptor-specific kinetics of desensitization can determine the size, time course and frequency of transmitted signals. Desensitization is thus a surprisingly versatile mechanism for shaping synaptic transmissions.
ASJC Scopus subject areas