Coactivation of multiple tightly coupled calcium channels triggers spontaneous release of GABA

• DOI: 10.1038/nn.3162
• Publication Date: 2012-07-29T18:58:48Z
• Authors: Courtney Williams; Wenyan Chen; Chia-Hsueh Lee; Daniel Yaeger; Nicholas P Vyleta; Stephen M Smith
• Keywords: Cerebral Cortex; 0301 basic medicine; Analysis of Variance; Patch-Clamp Techniques; Excitatory Postsynaptic Potentials; Calcium Channels, P-Type; Calcium Channel Blockers; Synaptic Transmission; Article; Calcium Channels, Q-Type; Mice; 03 medical and health sciences; Calcium Channels, N-Type; Animals; Calcium; Calcium Channels; Synaptic Vesicles; Cells, Cultured; gamma-Aminobutyric Acid

Voltage-activated Ca(2+) channels (VACCs) mediate Ca(2+) influx to trigger action potential-evoked neurotransmitter release, but the mechanism by which Ca(2+) regulates spontaneous transmission is unclear. We found that VACCs are the major physiological triggers for spontaneous release at mouse neocortical inhibitory synapses. Moreover, despite the absence of a synchronizing action potential, we found that spontaneous fusion of a GABA-containing vesicle required the activation of multiple tightly coupled VACCs of variable type.