I posted this on another thread, but I think people need to see it, so here it is again.
****The following is copied from
http://en.wikipedia.org/wiki/Cannabinoid
Cannabinoid Receptors
Before the 1980s, it was often speculated that cannabinoids produced their effects through nonspecific interaction with cell membranes, instead of interacting with specific receptors. The discovery of the first cannabinoid receptors in the 1980s helped to resolve this debate. These receptors are common in animals, and have been been found in mammals, birds, fish, and reptiles. There are currently two known types of cannabinoid receptors, called CB1 and CB2.
CB1 receptors are found primarily in the brain, specifically in the basal ganglia and in the limbic system, including the hippocampus. They are also found in the cerebellum and in both male and female reproductive systems. CB1 receptors are essentially absent in the medulla oblongata, the part of the brain that is responsible for respiratory and cardiovascular functions. Thus, there is not a risk of respiratory or cardiovascular failure as there is with many other drugs. CB1 receptors appear to be responsible for the euphoric and anticonvulsive effects of cannabis.
CB2 receptors are almost exclusively found in the immune system, with the greatest density in the spleen. CB2 receptors appear to be responsible for the anti-inflammatory and possible other therapeutic effects of cannabis.
****This is copied from
http://en.wikipedia.org/wiki/Cannabinoid
