Muscarinic cannabinoid suppression of excitation, a novel form of coincidence detection

Abstract Δ9-tetrahydrocannabinol (THC), the chief psychoactive ingredient of cannabis, acts in the brain primarily via cannabinoid CB1 receptors. These receptors are implicated in several forms of synaptic plasticity – depolarization-induced suppression of excitation (DSE), metabotropic suppression of excitation (MSE), long term depression (LTD) and activation-dependent desensitization. Cultured autaptic hippocampal neurons express all of these, illustrating the rich functional and temporal heterogeneity of CB1 at a single set of synapses. Here we report that coincident activation of muscarinic acetylcholine receptors and