Biochemical mechanisms in the brain
Cannabinoids usually contain a 1,1′-di-methyl-pyran ring, a variedly derivatized aromatic ring and a variedly unsaturated cyclohexyl ring and their immediate chemical precursors, constituting a family of about 60 bi-cyclic and tri-cyclic compounds. Like most other neurological processes, the effects of cannabis on the brain follow the standard protocol of signal transduction, the electrochemical system of sending signals through neurons for a biological response. It is now understood that cannabinoid receptors appear in similar forms in most vertebrates and invertebrates and have a long evolutionary history of 500 million years. The binding of cannabinoids to cannabinoid receptors decrease adenylyl cyclase activity, inhibit calcium N channels, and disinhibit K+A channels. There are at least two types of cannabinoid receptors (CB1 and CB2).
Sustainability in the body
Main article: Cannabis drug testing
Most cannabinoids are lipophilic (fat soluble) compounds that are easily stored in fat, thus yielding a long elimination half-life relative to other recreational drugs. The THC molecule, and related compounds, are usually detectable in drug tests from 3 days up to 10 days according to Redwood Laboratories; long-term users can produce positive tests for two to three months after ceasing cannabis use (see drug test).