MATTHEW P. ROWEStudying scorpions comes with its share of danger, as biologist Bryan Fry of the University of Queensland knows all too well. On a 2009 trip to the Brazilian Amazon, Fry was stung while trying to collect the lethal Brazilian yellow scorpion (Tityus serrulatus), and for eight hours he says it felt as though his finger was in a candle flame. Meanwhile, his heart flipped between racing and stopping for up to five seconds at a time. “At least the insane levels of pain helped keep my mind off my failing heart,” Fry writes in an email to The Scientist.
His symptoms were caused by an arsenal of toxins in the animal’s sting, which contribute to one of the most painful attacks in the animal kingdom. But at least one mammal—the southern grasshopper mouse (Onychomys torridus)—regularly chows down on Arizona bark scorpions (Centruroides sculpturatus) and doesn’t seem to experience pain, despite receiving plenty of stings. In 2013, Ashlee Rowe, now of Michigan State University, and colleagues showed that bark scorpion venom interacts with the NaV1.8 voltage-gated sodium channel in grasshopper mice, in addition to activating the NaV1.7 channel as it does in other mammals (Science, 342:441-46).
Rowe’s team showed that grasshopper mice have evolved amino acid changes in NaV1.8 that allow it to bind scorpion venom components, and in turn prevent the channel’s activation. Because ...
