CaMKII Is Involved in the Choline-Induced Downregulation of Acetylcholine Release in Mouse Motor Synapses

Abstract

We investigated the involvement of calcium-dependent enzymes, protein kinase C (PKC) and calcium-calmodulin-dependent protein kinase II (CaMKII), in the signaling pathway triggered by the activation of presynaptic alpha7-type nicotinic acetylcholine receptors by exogenous choline, leading to downregulation of the evoked acetylcholine (ACh) release in mouse motor synapses. Blockade of PKC with chelerythrine neither changed the evoked release of ACh by itself nor prevented the inhibitory effect of choline. The CaMKII blocker KN-62 did not affect synaptic activity but fully prevented the choline-induced downregulation of ACh release.