Rodents called grasshopper mice have an unusual favorite food. Not grasshoppers. No, they really like scorpions. You can see the problem. But the mice shrug off any scorpion stings. And a new study shows how.

Researchers injected common house mice with scorpion venom. The mice nursed the injection site for several minutes. But grasshopper mice injected with venom fussed for only a few seconds. In fact, they were more bothered by saline solution. 

So what’s going on? In the house mouse, a specific type of nerve-cell signaling-channel got activated by the venom. But this same channel in grasshopper mice stayed inactive in the presence of venom—meaning the mice remained blissfully ignorant.

In addition, a separate pathway did react to the scorpion venom—and it actually temporarily blocked pain signals. Meaning that for grasshopper mice, scorpion venom is actually an analgesic. The work is in the journal Science. [Ashlee H. Row et al., Voltage-Gated Sodium Channel in Grasshopper Mice Defends against Bark Scorpion Toxin]

Understanding details of this system could lead to new approaches in the treatment of pain in people, so that someday we might ask, “Scorpion, where is thy sting?”

—Sophie Bushwick

[The above text is a transcript of this podcast.]