Pity the tiny naked mole-rat. The buck-toothed, sausage-like rodent lives by the hundreds in packed, oxygen-starved burrows some six feet under ground. It is even cold-blooded -- which, as far as we know, is unique among mammals.You can feel their pain. But, they can’t feel ours. Evolution has benefited naked mole-rats by ridding them of a body chemical called Substance P, a neurotransmitter released by pain fibers that send signals to the central nervous system in mammals after making contact with things that cause long-lasting, achy pain. A better understanding of how Substance P works in the strange rodents may lead to new analgesic drugs for people with chronic pain who do not respond well to current medication, according to Thomas Park, associate professor of biological sciences at the University of Illinois at Chicago, and Gary Lewin of the Max-Delbrück Center for Molecular Medicine in Berlin, principal authors of a study appearing Jan. 29 in the free-access journal PLoS Biology.
