Southern grasshopper mice may weigh only a couple ounces, but they have the ability to ward off the deadly sting of bark scorpions. A study at Michigan State University found that the scorpion toxin acts like a pain killer in the system of the mice rather than causing severe pain and death.
The bark scorpion is the most venomous scorpion in North America. Its venom causes severe pain that is similar to electrical jolts. Grasshopper mice are rodents that normally prey on grasshoppers, scorpions, worms, and snakes.
The research showed that grasshopper mice have different amino acids in one of their pain neuron sodium channels, causing the scorpion toxin to bind to the amino acid and block the pain response. In other words, the toxin acted like a pain killer in the mice.
While the scientists do not totally understand the mechanism that causes the mice to feel no pain from the venom, they do point out that there are other examples of mammals being resistant to prey toxins. For example, the mongoose is resistant to the toxin from the cobra snake.
The research is important because it could lead to the development of analgesic medications for humans.