Facilitation of brain stimulation reward by delta 9-tetrahydrocannabinol.

The present experiment explored whether delta 9-tetrahydrocannabinol (delta 9-THC), the psychoactive ingredient in marijuana, shares with other drugs of abuse the ability to facilitate brain stimulation reward acutely, as measured by electrical 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. delta 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.