Cannabinoids are reported to rescue cocaine-induced seizures (CISs), a severe complication in cocaine users. However, the molecular targets for cannabinoid therapy of CISs remain unclear. Here, we report that the systemic administration of cannabinoids alleviates CISs in a CB1/CB2-receptor-independent manner. In HEK293 cells and cortical neurons, cocaine-induced dysfunction of the glycine receptor (GlyR) is restored by cannabinoids. Such restoration is blocked by GlyRα1S296A mutation. Consistently, the therapeutic effects of cannabinoids on CISs are also eliminated in GlyRα1S296A mutant mice. Based on molecular dynamic simulation, the hydrogen-bonding interaction between cocaine and the GlyR is weakened by cannabinoid docking. Without altering cocaine distribution across the brain, cannabinoids significantly suppress cocaine-exaggerated neuronal excitability in the prefrontal cortex (PFC) and hippocampus by rehabilitating extra-synaptic GlyR function. Microinjection of cannabinoids into the PFC and hippocampus restores cocaine-puzzled neural activity and alleviates CISs. These findings suggest that using GlyR-hypersensitive cannabinoids may represent a potential therapeutic strategy for treating CISs.
Keywords: cannabinoids; cocaine; extra-synaptic; glycine receptor; hippocampus; prefrontal cortex; seizure.
Copyright © 2020 The Author(s). Published by Elsevier Inc. All rights reserved.