[Effects of nicotine and cannabinoids on the central nervous system]

We describe the molecular mechanisms of action of nicotine and delta 9-tetrahydrocannabinol, the most potent component of cannabis. Like other drugs of abuse, these compounds enhance dopamine release in a precise area of the limbic system when administered acutely. It has recently been shown that the cannabinoid receptors on which delta 9-tetrahydrocannabinol acts are also activated by endogenous ligands such as anandamide. This unconventional neurotransmitter appears to have important physiological effects in the central nervous system. Both preclinical and clinical evidence suggests that nicotine is more addictive than delta 9-tetrahydrocannabinol. However, the intimate interactions that exist between cannabinoid and opioid systems within the brain suggest that cannabinoids should not be considered as harmless drugs of abuse.