Scientists still dont know the whole story of how marijuana makes people high. But theyve just taken a big step forward in our understanding of pots effect on the human body by figuring out the three-dimensional structure of cannabinoid receptor 1 (CB1).

CB1 is the large protein molecule in nerve cells that is activated by marijuanas main mind-altering constituent, tetrahydrocannabinol (THC), spurring the cellular processes that lead to the euphoria and other effects familiar to pot smokers.

In addition to yielding a better understanding of marijuanas mind-altering effects, knowing the ins and outs of CB1s complex structure (see illustration below) could speed development of drugs for conditions ranging from pain and inflammation to obesity and substance abuse.