Scientists hope to learn whether stress could pass through channels completely distinct from squawks, squeaks and raised hackles. What they learn could inform animal treatment and shed light on the nature of stress in humans.
In 2014, Bains started investigating in his University of Calgary lab how. He found that a stressed mouse emits a pheromone from its anal glands, which is then sniffed by a nearby mouse.
“It kind of makes sense, right?” Bains said. “If you think of what a mouse would do — it might be out in the field and get chased by a predator, and it comes back to the nest. “A vocal signal would probably attract attention, but a silent chemical signal, which is only detected by those who are very close to you, would be a great way to inform others that there’s a danger,” Bains added.Bains found that neuronal connections in a mouse that smells stress pheromones will change to become identical to the mouse that first experienced the stressor. So the brain of a mouse that smelled a stressed mouse looks as though it felt a stressor, too.
Next, “we … asked whether a stressed mouse could transmit the information to a second mouse, and whethermouse,” Bains said. “And it works beautifully. The third mouse shows the same changes in its brain.”“We think of ourselves really as individuals who have our own experiences,” Bains said. “And we don’t think very much about how the experiences of others and what they’re going through might also shape us.”Measuring stress in wild animals is difficult outside a neuroscience lab.