The interaction of delta9-tetrahydrocannabinol with cholinomimetic drugs in an agonist-antagonist paradigm.

In rabbits, i.v. delta9-tetrahydrocannabinol (delta9-THC) at 0.5 mg/kg was challenged with i.v. arecoline (0.025 mg/kg), nicotine (0.02 mg/kg) or physostigmine (PHYSO, 0.05 mg/kg), and observations were made on quantified EEG and behavior. The cholinomimetics effectively reversed the cortical and hippocampal EEG alterations induced by delta9-THC. Arecoline and PHYSO temporarily reversed the behavioral-sedative effects of delta9-THC whereas the combination of delta9-THC with nicotine produced behavioral collapse preceded by behavioral disturbance.