Sci is at Neurotic Physiology today, talking about a recent study looking at a single nucleotide polymorphism in the mu-opioid receptor. It's a simple, single mutation, that has some pretty big effects, especially in pain sensitivity. Though it does make me wonder, why does every picture of back pain have a shirtless person with a glowing back? I guess you can't have back pain with your shirt on. Head over and check it out.
The views expressed are those of the author(s) and are not necessarily those of Scientific American.