- So many of us are caught up in the rat race,
that endless loop of driving to work,
toiling away, driving back, all for just a few crumbs.
But behold the literal rat race,
in which researchers trained rodents to drive tiny cars.
Surprisingly, unlike for most of us humans,
the driving actually seems to lower the rats' stress levels,
but maybe that's partly because at the end,
if they were good drivers, they got Froot Loops.
To find out more, we talked with
researcher Kelly Lambert about
her rodent-operated vehicles, those would be ROVs,
and what implications this might have for humans.
So, what is this research
that you're carrying out here with rodents?
- We wanted to teach rats to drive cars!
It's a complex task, and so we used some old-fashioned
psychological behavioral training techniques
and Froot Loops to shape rats to get into cars
and to use the car as a tool
to navigate an environment to get to that ultimate reward,
which is the Froot Loop.
And so we looked in our most recent study
to see if the complexity of their environments,
if they had an enriched environment or not,
influenced how quickly they could learn.
And it did.
- Walk us through the experimental setup here.
- We had two groups.
One group was housed in an enriched environment,
kind of a Disneyland of sorts for rats.
So, they had different stimuli to interact with,
and the other group was in just standard laboratory cages.
So, they had everything they needed but no Disneyland.
And so we were interested in,
if the enriched environment would facilitate
their learning to drive.
We'd already shown that we could teach the rats to drive,
and we also taught them to steer.
So, we had forward driving bars,
and then bars on the left and right
so they could steer in different directions.
But they were able to do some pretty complex turns.
- What made a, quote unquote, good rat driver?
- To drive four times, four clean drives,
jumping in the car, getting to the Froot Loop reward,
and then coming back and doing that again.
So, only our enriched environment animals
were able to do that.
None of our standard housed animals.
They could get bits and pieces of it,
but they were not able to put it together
more than one time.
So, in that particular study,
our standard housed animals
did not get a driver's license. [laughing]
- They have to wait in line again at the DMV
to take their test. - Yeah, yeah.
Not fun, even for a Froot Loop.
- What kinds of vehicles do you give to a rodent in the lab?
- We could not find one on Amazon [laughing]
so we had to build our own.
So, we started with a basic plastic container
and we cut a window out and put the bars,
the steering bars at the end
so that they could just grab the bars,
that they would complete the circuit,
the electrical circuit.
Although the rats couldn't feel anything.
And we added wheels.
So that's our rodent operated vehicle design.
Very simple.
- You actually could tell that
they might actually be somewhat enjoying this process?
Can you talk about how you were able to measure that?
- So, what we did with this last published study.
Once we taught them to drive,
then we took the reward away.
It's called extinction trials.
And we did that for four days.
And even the fourth day
after they've been driving and getting nothing,
they would still jump right into the car very quickly.
That suggested that they had
a positive association with that.
So, that's one way we've gotten at this question of,
is this a pleasurable experience, or a positive experience?
The stress part.
So, our very glamorous lab that I have,
we like to measure stress hormones in rat poop.
We can extract the hormones
and we look at a stress hormone
that is similar to cortisol in humans,
but it's corticosterone in rats.
And then another hormone is DHEA,
is the abbreviation.
Our research suggests that DHEA kind of
buffers against the toxicity
of chronically high stress hormone levels
and throughout the training
for all of the animals in this published group,
regardless of whether or not
they were in the standard group or the enriched group,
the DHEA to quart ratio went up in a healthy way.
So, that suggests that it's healthy.
And then in a previous study that hasn't been published,
we had a different design where we had
half the animals were drivers, like we'd done before.
And then half the animals,
we drove them around the same distance
with the same car, but did it via remote control.
We called those the Uber rats,
they were just passenger rats versus the driver rats.
And in that study, only the driver rats
had the increased DHEA.
- So, what comes next with these rats in your lab?
Are you gonna make rat race-cars?
[Kelly laughing] SUVs for their friends?
- We thought about a little competition.
So, we're thinking about neuroplasticity,
and getting to the brain measures of neuroplasticity.
Neuroplasticity refers to the brain's ability to change
to alter environments or lifestyle.
So in my lab, we're looking at physical measures.
I like to look our rats at the end of their lives,
they're still alive and driving,
and then maybe compare their brains to
brains of rats that did not receive the training
to see if they have some of those measures
of neuroplasticity.
- And we just have to be careful
when we maybe extrapolate what we're finding here
with rodents up to humans,
but I was wondering if you could talk about
what this might suggest about how our own brains might work
when it comes to stimulation and learning.
- We needed engagement with our physical worlds
and our social worlds,
and our brains need experience to develop.
So, I think it can be generalized
or translated to the human brain.
Another kind of something I thought about is,
I wonder, since a lot of biomedical research
is conducted on rats in those standard boring cages,
if that is influencing the validity
of the results that we're finding?
And I think we need to be looking at
more authentic behaviors and complex behaviors.
And if we want to learn about
our complex emotional disorders, our cognitive changes,
we probably need to look at more complex research designs.
So, I think we need to step up our game as scientists,
and look at something besides a rat and a mouse,
and also look at behaviors beyond pressing a bar
or turning right or left in a simple maze,
because even the rat brain can do so much more than that.
- So, you saw that there was actually
some enjoyment that these rats were getting
out of learning this new task.
Might that be kind of the same for humans?
Learning a new language or learning to do cabinetry?
Whatever floats your boat.
- Absolutely.
I think that we have individual differences
in what we like, but engaging in different tasks,
I think more interactives,
can be really good for the brain.
So, learning is an enjoyable experience,
and I think it gives us a sense
that we're gaining control over our environment.
A sense of mastery.
And this makes us feel better about
our competency in this world.
So, even though it's kind of a simplistic idea,
teaching a rat to drive a car,
it seems to be taking us into some complex,
even philosophical [laughing] kind of arenas
as we think about what brains can do.
- Thank you for taking the time to chat with us.
- It's been my pleasure.
Thank you for your interest in our driving rats.
[light, curious music]