The Fast and the Furriest

Who knew that rats on wheels could hold a key to the future of neuroscience?

Kelly Lambert, professor of behavioral neuroscience at the University of Richmond, is forging new ground in understanding how our environment influences our brains’ ability to adapt.

Her research centers around experience-based neuroplasticity, or how the brain changes over time. Three decades of research have shown her how human brains benefit when we interact with our environment to achieve a goal — and how they suffer when they don’t.

Lambert’s partners in these studies (along with her undergraduate student researchers) are the rats in her lab. “Rat brains have all the same areas and neurochemicals that our brains have … so it’s a good starting point, a model, to use to learn more about the human brain,” said Lambert.

“Rats use internal cues about their own movement to navigate their environments and return back to their original starting positions — even when no obvious external cues are present. Basically, they have their own internal GPS navigational systems!”

Dr. Kelly Lambert poses with Sophia, a Long Evans rat and adept operator of a motor vehicle. By teaching rats to drive, Lambert is shedding new light on brain development and treatment of mental illnesses.

Riding in Cars with Rats

In her latest research, Lambert decided to test this rodent GPS and its relation to neuroplasticity in the brain. With a team of student and faculty collaborators, Lambert taught the rats to drive small cars in pursuit of a reward.

Lambert’s 17 lab rats took turns operating their rodent-operated-vehicles (ROVs) — cars that the research team custom-built from plastic food containers. Using a steering wheel made from copper bars, the rats navigated their vehicle through rectangular arenas toward the end of the course. Rats who passed their driving tests were rewarded with Froot Loops at the finish line.

The study’s main goal was to measure the impact of the rats’ upbringing and environment on its performance in these driving tasks. Thus, before the driving tests began, the rats were divided into two groups that lived in very different environments.

One group of rats lived in a complex and “enriched” environment, which provided them with toys, balls, and other objects designed to stimulate brain activity. This group lived together in a f-rat house of sorts, which promoted interaction and relationships among the rodents. The other group resided separately in standard laboratory cages, which offered no additional opportunities for externally driven mental stimulation.

The study yielded interesting results. The rats from the enriched environment quickly learned and adapted to the intricate task. They showed much greater skill in operating and steering their ROVs — a testament to their brains’ improved neuroplasticity from living in an enriched environment.

Only the rats from the enriched environment were able to navigate the correct path four consecutive times. The rats from the standard lab environment, on the other hand, “failed their driving test,” said Lambert.

These results reinforce that, to operate at peak performance, brains demand stimulation and interaction with new tasks and with the outside world.

One group of rats grew up in an “enriched” environment –– equipped with objects to stimulate brain activity and interaction.

Protecting Against the Rat Race

By teaching these rats the art of the stick shift, Lambert says we can learn even more about cognitive development in humans and how we might more effectively treat mental illnesses.

When Lambert and her team analyzed both groups of rats’ fecal samples after their driving tests, they found increased levels of two hormones: corticosterone and dehydroepiandrosterone (DHEA).

Corticosterone serves as a marker of stress, secreted in response to environmental challenges. DHEA counteracts it, stepping in as a buffer when corticosterone becomes toxic. (These hormones serve similar functions in humans, as well.) Lambert found that, as the rats progressed through their driving training, the ratio of DHEA to corticosterone increased.

Even in extinction trials — driving tests in which the Froot Loop reward was removed — hormone analysis reflected similarly decreased stress levels. This implies that the rats found practicing their new task enjoyable and relaxing, even without the expectation of a reward.

The presence of these hormones suggest that regularly engaging in complex tasks can strengthen emotional resilience — whether for rats or for humans. While human brains are more complex than those of rats, Lambert says these results imply “universal truths” in how we interact with our environment to promote improved mental health.

For one, these findings can have ripple effects across the field of mental health as we know it. Through better understanding the brain’s neuroplasticity in response to new or stressful tasks, we can discover more effective treatments for anxiety, depression, or schizophrenia.

Lambert says that emotional resilience is one of our body’s first defenses against mental ailments. This research suggests that something as simple as learning a new task or working with our hands can jumpstart that protection.

She refers to this as the concept of “behaviorceuticals” — activities that promote production of the feel-good hormones that stave off stress. “Anything that reduces stress can build resilience against the onset of mental illness,” said Lambert.

In the study’s next phase, Lambert plans to further refine her research around behaviorceuticals and experience-based neuroplasticity. She plans to teach the rats more advanced driving techniques and subsequently measure how this increased challenge and mastery affects their hormone levels.

“This research could have therapeutic value as we learn more and help us better understand mental illnesses and mental health,” said Lambert.

And though it won’t result in a DMV-issued rodent license, the rats are happy to be in the drivers’ seats.

In her next phase of research, Dr. Lambert plans to teach the rats more advanced driving techniques and measure how mastery of a task impacts the brain’s neuroplasticity. Coming soon: Rat donuts in the parking lot!

This content was paid for and created by the University of Richmond. The editorial staff of The Chronicle had no role in its preparation. Find out more about paid content.