So-called 'synthetic marijuana' linked to serious health problems
Researchers discovered several decades ago that the primary psychoactive compound in marijuana, ?9-THC, activates two receptors, CB1, found in high abundance in the brain and central nervous system, and CB2, found primarily in the immune system. To study these receptors, researchers identified other naturally occurring chemicals and developed synthetic cannabinoid (SCB) compounds that also bind to them; collectively, these compounds are known as cannabinoids. Although they activate the CB1 and CB2 receptors, SCBs and other cannabinoids are otherwise chemically distinct from marijuana and often from each other. SCBs are now marketed and sold as synthetic marijuana under names such as "K2" and "Spice." "It started in the early 2000s in Europe, and in the U.S., in 2007 or so, we started seeing all kinds of people coming into emergency rooms saying they smoked marijuana, but then they had these really bizarre symptoms that did not correspond with the effects y...