Scientific knowledge on marijuana's mechanism of action.

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Section 3) Scientific knowledge on marijuana’s mechanism of action.

Most popular assertions about marijuana’s affect on the human body and brain are based on what is now viewed by the scientific community as a discredited hypothesis.

The discovery of a cannabinoid receptor system in the human body began a scientific revolution that radically altered contemporary knowledge about marijuana’s effects on the body and brain.

The cannabinoid receptor system accounts for almost all of marijuana’s characteristic effects, as well as the substance’s low toxicity.

The receptor has also been cloned, an endogenous ligand has been identified, and an antagonist has also been discovered. A structure-activity relationship for the ligand has also been established.

The cannabinoid receptor system responds to continued exposure to marijuana by reducing the number of receptors available for binding; the discovery of this tolerance mechanism for marijuana discredits the prior hypothesis that tolerance to marijuana resulted from a desensitization of brain cells, and supports the assertion that tolerance to marijuana does not contribute to a dangerous dependence liability.

The existence of the cannabinoid receptor system has clarified concern over marijuana’s possible effects on the immune system, giving credence to claims that such effects pose no threat to human health.

The existence of the receptor system explains why marijuana has never been proven to cause brain damage.

The discovery of the receptor system and the resulting research provides great promise for development of a new class of effective pharmaceutical drugs, and may enable scientists to learn more about the chemistry of emotions.

These new research findings contradict many of the DEA’s on-record findings of fact about marijuana, findings which have been used in the past to block reconsideration of marijuana’s scheduling status.

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