“The rat is an appropriate model for the human brain in many ways since it has all the same areas and neurochemicals as the human brain — just smaller, of course,” said Kelly Lambert, professor of behavioral neuroscience, in a statement. “Although humans are more complex than rats, we look for ‘universal truths’ about how brains interact with environments to maintain optimal mental health.”
Lambert and her research colleagues created small cars made out of clear plastic containers, according to the study. The cars’ floors were made of aluminum, and they had three paw-gripping copper bars that acted as steering wheels.
When the rats grasped the copper bars with their paws, it created an electrical current that powered the car and moved it in different directions, depending on which bar the rats were holding on to. Moving the car forward usually led the rats to a sugary treat of Froot Loops.
Scientist knew the rats were more chill and less anxious when they got to drive the cars by testing their excrement for stress hormones. The rat-poop tests showed increased dehydroepiandrosterone (DHEA), the hormone that thwarts stress. And the rats that actually got to drive the cars, researchers found, appeared to be less stressed than rats that were merely passengers in remotely controlled versions.
“When we measured hormones associated with stress (corticosterone) and resilience (DHEA) in their poop, we found that, regardless of the housing group, the training itself changed the hormones in a healthy trajectory,” Lambert said. “Therefore, we found that driving training led to more resilient stress hormone profiles.”
The driving rats in the study held an interest in driving throughout the trial and showed more learning capacity when compared with rats that were less stimulated. The results of the study could impact future research on how Parkinson’s disease alters motor skills and spatial function in humans, Lambert told New Scientist. It could also be used to study how depression influences motivation.
The complex cognitive, motor and behavioral functions in the rats that were demonstrated in the study could allow researchers to learn about the neural basis of the difficult functions, said Chandramouli Chandrasekaran, a professor of neurobiology at Boston University School of Medicine.
“Beyond the adorableness, there’s a real scientific value,” he said, noting that the rats likely used various parts of their brains to drive toward their treats.
Lambert said her team will focus next on how rats have the capability to learn driving skills and why it seems to alleviate stress, according to New Scientist.
Continuous stress in humans can severely affect a person’s immune, digestive and reproductive systems, according to the National Institute of Mental Health. Stress can also be a risk factor for mood disorders such as depression and anxiety, according to researchers at the University of California at Berkeley. An April Gallup poll found that Americans are among the most stressed in the world and that 45 percent of Americans reported that they felt worried a lot.
Lambert’s lab is studying how to help that as it focuses on how the brain is able to healthily change over time. It also investigates how ongoing stress affects mental health.
“We want to identify healthy coping strategies to minimize the negative impact of chronic stress,” she said.