Diversity of presynaptic calcium channels displaying different synaptic properties.

Why mediate P-/Q-type and not N-type Ca2+ channels in cerebellar inhibitory interneurons? Neurotransmitter release relies most on P-/Q- and N-type Ca2+ channels in the vast majority of neurons, although all types of voltage-gated Ca2+ channels are competent in initiating exocytosis. Up to date, it remains unclear why a particular Ca2+ channel type mediates neurotransmission in certain axon terminals and another type of Ca2+ channel evokes neurotransmission in axon terminals of another region. Therefore, the present review analyzes the diversity of presynaptic Ca2+ channels displaying different synaptic properties and focuses on an analysis of distribution and function of presynaptic voltage-gated Ca2+ channels, as well as on developmental changes.