Facilitation of brain stimulation reward byΔ 9-tetrahydrocannabinol

The present experiment explored whetherΔ ⁹-tetrahydrocannabinol (Δ ⁹-THC), the psychoactive ingredient in marijuana, shares with other drugs of abuse the ability to facilitate brain stimulation reward acutely, as measured by clectrical intracranial self-stimulation (ICSS). Laboratory rats were implanted with stimulation electrodes in the medial forebrain bundle, and trained to stable performance on a self-titrating threshold ICSS paradigm.Δ ⁹-THC, at a dose believed pharmacologically relevant to moderate human use of marijuana, acutely lowered ICSS thresholds, suggesting that marijuana acts on similar CNS hedonic systems to most other drugs of abuse.