Reid, Christopher MBekkers, JohnClements, John D2015-12-132015-12-130166-2236http://hdl.handle.net/1885/78306A key step in the release of neurotransmitter is the entry of Ca 2+ into the presynaptic terminal via voltage-activated Ca 2+ channels. N-type and P/Q-type Ca2+ channels play a predominant role but, surprisingly, their distribution across presynaptic terminals lacks any apparent order. They form a patchwork: at some terminals only N-type channels contribute to transmitter release and in others only P/Q-type channels contribute, but in many terminals both sub-types are active. The physiological implications of this non-uniform distribution are starting to emerge. Recent studies reveal that G-protein-mediated depression of N-type channels is stronger than that of P/Q-type channels, whereas voltage-dependent relief of inhibition is more pronounced for P/Q-type channels. The patchwork distribution of Ca2+ channel subtypes might therefore enable terminal-specific modulation of transmitter release, enhancing the power of synaptic processing.Keywords: calcium channel N type; calcium channel P type; calcium channel Q type; calcium ion; guanine nucleotide binding protein; neurotransmitter; molecular dynamics; nerve ending; neuromodulation; neurophysiology; neurotransmitter release; nonhuman; postsynaptic200310.1016/j.tins.2003.10.0032015-12-11