Scientists from Brown University have shown for the first time that cannabinoids - compounds similar to the active ingredient in marijuana but which can also occur naturally in the body - play a major role in pain suppression in rats. Previous research had shown that stimulation of the top side of a brain region associated with pain control known as the "PAG" could bring about the release of pain-reducing substances similar to natural opiates.
The new work showed that stimulation of the lower side of the PAG caused the release of the cannabinoid-like substances. The findings may lead to better drugs which make use of these pain control pathways.