Can a Brain-Shrinking Mole Help Alzheimer's Patients?

Certain small mammal species – shrews, voles, stoats, weasels – shrink their brains and other organs in wintertime, a strategy that helps them conserve energy when food is scarce. Now the European mole (Talpa europaea) has been found to deploy this same weird adaptation.

Researchers at the Max Planck Institute of Animal Behavior reports that European moles shrink their brains by eleven percent in winter, and regrow them by four percent by summer. Rather than shut it all down in hibernation like a normal mammal, the mole keeps moving and eating, only with a smaller brain.

“They have extremely high metabolisms and year-round activity in cold climates,” says co-author Dina Dechmann. “Their tiny bodies are like turbocharged Porsche engines that burn through energy stores in a matter of hours.”

Skull and brain shrinkage, a process known as Dehnel's phenomenon, was first observed in shrews in the 1950s. In the past five years, Dechmann and colleagues have shown that the weirdness also occurs in stoats and weasels.

There might be practical applications to understanding the phenomenon. “That three distantly related groups of mammals can shrink and then regrow bone and brain tissue has huge implications for research into diseases such as Alzheimer’s and osteoporosis,” says Dechmann. “The more mammals we discover with Dehnel’s, the more relevant the biological insights become to other mammals, and perhaps even to us.”

Photo credit: Javier Lázaro