Chiu et al. found that activation of SST-expressing interneurons induces tonic currents through dendritic α5-containing GABA receptors in pyramidal neurons of the neocortex. Tonic GABAergic hyperpolarization deinactivates dendritic voltage-gated calcium channels, enhancing calcium influx during action potentials. Increased dendritic calcium signaling facilitates calcium- and endocannabinoid-dependent inhibitory synaptic plasticity.
