Richmond (United States) (AFP) – The girls can’t hide their excitement as they take to the racing arena.
Blacktail is up first, taking a few seconds to sniff out her surroundings before placing her paw on a lever and zooming off.
After storming the finish line, she devours a well-earned Froot Loop hanging from a “treat tree.”
Black Tail is one of the University of Richmond’s Rat Drivers – a group that first wowed the world with their ability to drive tiny cars in 2019.
Now, the rodents serve as ambassadors for the school’s Behavioral Neuroscience Lab, headed by Professor Kelly Lambert.
“It draws people’s attention to how smart and learned these animals are,” explained Lambert, who has to balance her love of furry runners with the need for scientific detachment — naming them only by the Sharpie colors that mark their tails. Theirs.
The idea of racing with rodents started as a playful challenge from a colleague.
But far from being an act of novelty, the animals are part of a boundary-pushing project exploring the ways in which environmental enrichment sculpts the brain — and in turn may have potential for solving human mental health challenges.
For Lambert, one of the great failures of modern medicine has been its inability to cure mental illness through drugs, even as pharmaceutical companies have reaped huge profits.
These pharmaceutical approaches have faced increasing scrutiny since a landmark study published in July questioned the theory that chemical imbalances, specifically a lack of serotonin, cause depression.
The beginnings of their work
Instead, Lambert sees behavioral therapy as the key to treating the mind, which is where the study of other mammals comes in.
“Our brains are changing, from the womb to the grave,” she said. “If we have an engaged kind of life, that’s probably important and related to depression.”
An earlier experiment of hers had divided rats into groups of “workers” who were assigned an effort-based reward task to dig through mounds of dirt for a Froot Loop – or a control group of “trust fund” rats. who simply surrendered. treat.
When challenged with stressful tasks, working rats lasted longer than those conditioned to remain in a state of what psychologists call “learned helplessness.”
And when tasked with swimming, the working rats showed greater emotional resilience, as indicated by a higher ratio of the hormone dehydroepiandrosterone to cortisol in their feces.
Mice that learned to drive also had biomarkers of greater resilience and reduced stress — which Lambert suggests may be related to the pleasure of acquiring a new skill, like a human mastering a new piano piece.
“They make trails that take them over and over again in the wild, and we wanted to see if they could continue to have this great navigational ability in a vehicle,” explained research lab specialist Olivia Harding.
The training wasn’t simple: the team first tried to get the mice to push directional control with their noses, before discovering that the animals preferred to stand on their hind legs and use their front paws.
Early models of cars required rats to touch wires located at the front, left, or right of the car, completing a smooth electrical circuit corresponding to the direction of movement.
Now, however, they ride on fancier rides with levers created by a roboticist.
Even when their cars were placed in an unfamiliar, treatment-directed location, the rats learned to return their vehicles and navigate to the reward, indicating advanced cognitive processing at work.
Today’s paddling ladies, Blacktails and Piedtails, show clear signs of “anticipatory” behavior when people enter the room, pacing back and forth and trying to climb their walls.
However, just like humans, not all rats have similar interests: while some individuals seemed eager to drive just for fun, others did it just for pleasure, while still others could not be induced to participate at all.
In the wild
Female mice in particular were long ignored by science because previous generations of researchers thought their four-day estrous cycles clouded research results.
That potentially deprived scientists of female-specific knowledge, a trend Lambert has been determined to reverse in her experiments — and is also a necessary condition for federal grants.
Lambert realized early in her career that studying rats living “unenriched” lives inside cages without obstacle courses and activities was of limited use, similar to studying humans in isolation.
In her driving study, rats raised in enriched cages did much better on driving tasks.
Her most recent paper focused on the differences between laboratory and wild-caught mice — finding that the latter had larger brains, more brain cells, larger disease-fighting spleens, and much higher levels of higher stress than their captive cousins.
“It blows my mind” that there has been so little interest in understanding these differences, given their potential impact on human medicine, she said.
It also raises an intriguing philosophical question: are we more like caged lab rats, enriched lab rats, or wild rats?
“I’m feeling a little closer to the predicted lab mouse than the wild mouse,” Lambert muses.
But wild mice, which must scavenge for food and avoid predators every day of their lives — just like our ancestors themselves — may have something to teach us about mental toughness.
© 2022 AFP