The Role of the CB1 Cannabinoid Receptor at the Frog Neuromuscular Junction

Abstract

Endocannabionoids are endogenous compounds that have been linked to the activation of endocannabinoid receptors, like CB1, in the brain. Endocannibinoids, via CB1 activation, are responsible for modulating inhibitory and excitatory responses through retrograde signaling. Here we show that CB1 activation through application of an endocannabinoid agonist, arachidonylcyclopropylamide (ACPA), causes a decrease in stimulus-induced end-plate potentials (EPPs) in the frog neuromuscular junction (NMJ). We found that EPP amplitude decreased significantly only after eight minutes postapplication, and remained depressed for an additional 36 minutes. This study demonstrates that retrograde signaling through endocannabinoid activation of CB1 receptors may influence synaptic transmission at the frog NMJ.