The significance of this neurobiological research on reinforcement mechanisms in the brain will be discussed in section 7 of this petition.

New scientific knowledge on the mechanism of action of marijuana in the human brain will be discussed in section 3 of this petition, after a review of pharmacological knowledge in section 2.

Scientific and medical evidence contrasting marijuana's mechanism of action in the brain with that of drugs of abuse such as heroin, cocaine, and amphetamine provide additional validity to the assertion that the non self-administration of marijuana or THC by animals is an indication that the drug does not have a significant dependence liability. This will be discussed in more detail in section 7. The relationship between marijuana and other cannabinoids will be addressed briefly in section 2 and more completely in section 8.

Sections 4, 5, and 6 of the petition will review data and reports which provide evidence of marijuana's actual use in society and its actual ramifications; this evidence will provide additional validity to the assertion that animal models are accurate in predicting marijuana's abuse potential.