ScienceDaily (June 13, 2011) — Definitive proof of an adverse effect of chronic marijuana use revealed at SNM's 58th Annual Meeting could lead to potential drug treatments and aid other research involved in cannabinoid receptors, a neurotransmission system receiving a lot of attention. Scientists used molecular imaging to visualize changes in the brains of heavy marijuana smokers versus non-smokers and found that abuse of the drug led to a decreased number of cannabinoid CB1 receptors, which are involved in not just pleasure, appetite and pain tolerance but a host of other psychological and physiological functions of the body.  FULL STORY AT SCIENCE DAILY: http://www.sciencedaily.com/releases/2011/06/110606131705.htm