They may hold the key to non-drowsy pain relief.
Normally, applying capsaicin to an animal's skin increases sensitivity to a heat stimulus. However, when Park applied capsaicin to a naked mole-rat's paw and then exposed the paw to the heat lamp, the animal did not respond at all.
Park's group then introduced Substance P to the naked mole-rats by applying a nonreproductive herpes simplex I virus to one paw. The virus enters nerve endings in the paw and migrates up the nerve fibers. The virus carries the DNA to produce Substance P, which can then be released into the spinal cord when nerve cells are stimulated with painful stimuli.
Park tells C&EN that it was a "really big shock" when his team applied the heat stimulus after introducing Substance P. "We were hoping to see something, maybe a slight increase in sensitivity, but we were really surprised when we found out that after introducing this one neurotransmitter, all of a sudden these animals behaved just like all the other animals that had been tested."
"These animals have evolved some way of modulating the levels of Substance P for whatever benefit to them. If we can learn from them how they did that biologically, it could help us develop new treatments," Park says.
I actually have a similar response to overcrowding, except that instead of losing nerve endings, I temporarily shut down my reasoning. Thus, I can survive untormented in even the most idiotic environment.
A brief introduction to Heterocephalus glaber.
(Yes, I realize that the pain-relief study is an old one. But I'd forgotten about it until now, when I was bouncing about the Internet looking for a good mole-rat primer. So I posted it under the guidance of the maxim "better late than never.)