These Rats Can Drive. What's Happening In Their Brains?

In neuroscientist Kelly Lambert https://psychology.richmond.edu/faculty/klambert/'s lab at the University of Richmond, rats hop into cars, rev their engines and skid across the floor of an arena. Researchers taught these tiny rodents to drive — and turns out, they really like it. But why? Host Regina G. Barber https://www.npr.org/people/1082526815/regina-g-barber talks with Kelly about her driving rats, and what they tell us about anticipation, neuroplasticity, and decision making. Plus, why optimism might be good for rats, and for humans too. Want to hear more fun animal stories? Let us know at [email protected] mailto:[email protected] — we read every email. Listen to every episode of Short Wave sponsor-free and support our work at NPR by signing up for Short Wave+ atplus.npr.org/shortwave http://plus.npr.org/shortwave. See pcm.adswizz.com https://pcm.adswizz.com for information about our collection and use of personal data for sponsorship and to manage your podcast sponsorship preferences. NPR Privacy Policy https://www.npr.org/about-npr/179878450/privacy-policy

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• 0:00Speaker 00

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• 0:15Speaker 00

  You're listening to Short Wave from NPR.

• 0:20Regina Barber?

  Hey, Short Wavers. Regina Barber here. And today, our story starts with a rat scientist.

• 0:26Speaker 02

  You know, I know we're not a big rat, and they're not little humans. But at a basic level, they have mostly all the same, all the same brain areas. Neurochemicals like dopamine and serotonin and, and plasticity kind of fertilizers that we look at. All of that is in a rat brain.

• 0:44Regina Barber?

  That's Kelly Lambert. She's a professor of behavioral neuroscience at the University of Richmond. And a while ago, this colleague of hers, a cognitive scientist who's into robotics and design, reached out with kind of a weird question.

• 0:57Speaker 02

  She sent an email one night. She said, Kelly, can you teach a rat to drive a car? And I consider myself a serious-minded neuroscientist, so my initial response was, why would I want to do that?

• 1:09Regina Barber?

  But then she reconsidered.

• 1:12Speaker 02

  Once you start thinking about teaching a rat to drive a car, you can't not think about, you can't stop thinking about it.

• 1:18Regina Barber?

  Fast forward to a couple of years later, guess what this is?

• 1:26Regina Barber?

  If you guessed that's the sound of a rat driving a tiny car, you're right. Kelly's rats are in a lab at the University of Richmond, zooming in these four-wheeled little plastic boxes around this big arena.

• 1:38Speaker 02

  Almost like a playpen around the entire room, and then some kind of flooring that we put, that we roll out, that's a flat surface. And it's black and white check, so it kind of has this raceway kind of idea. And we start the car on one end, and at the other end is what we call the Fruit Loop Tree. And we have little straws with Fruit Loops that they attach via marshmallows. We do give them healthy food. They just have these treats.

• 2:03Regina Barber?

  And in 2020, right at the peak of the COVID lockdown, watching these rats, Kelly had a breakthrough.

• 2:10Speaker 02

  We were all feeling isolated, low emotion. The students had been sent home. So I remember going in one day, feeling that low kind of feeling. And we had three rats that were our driver rats. And they ran up to the side of the cage, literally kind of jumping up and down like my dog, Brody, does. Want to say, you want to go for a walk? And he's flipping around. And they were reaching out to me. Now, maybe they just associated me with a big Fruit Loop. But it made me feel accepted, good, that they were excited for something.

• 2:45Regina Barber?

  So that's what Kelly and her team are studying now. Anticipation. They teach their rats how to drive these little cars in different situations and environments. And they study how these rats respond, how it changes their brains and their behavior. So today on the show, we're learning from rats about anticipation, decision making, and how to enjoy life. I'm Regina Barber, and you're listening to Short Wave, the science podcast from NPR.

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• 4:42Regina Barber?

  Hey, short wave-ers. Regina Barber here. Before we get back to the show, can you give me a quick minute to talk to you about what makes short wave possible? Aside from caffeine, a well-calibrated circadian rhythm, and a love of science, specifically astronomy, aside from all that, what really makes short wave possible is you. That's because we work for NPR, and NPR is public media, which means we exist not to make money, but to create a more informed public. Public media is kind of like a sidewalk or a public park. It's infrastructure that we all use. It's free. It's for everyone. That's why we work really hard to bring you stories about science that matter to you, no matter where you live or what community you belong to.

• 5:26Regina Barber?

  We love doing that work. So this time of year, we are saying, "Thank you. Thank you for listening. Thank you for your support." And wouldn't you know, it's Giving Tuesday. That means it's a perfect time to keep short wave going. Sign up for sponsor-free episodes and similar perks across more than 25 podcasts with NPR Plus today. Join us at plus.npr.org. That link is in our episode notes. And if you don't want podcast benefits, no one can stop you from simply just going to donate.npr.org. Your gifts are tax deductible either way you choose to give. Okay. Thank you for listening, and back to the show. Okay Kelly, describe this setup.

• 6:09Regina Barber?

  So like, what do the carts look like that the rats are driving? And how do they do it?

• 6:14Speaker 02

  Uh, right now, we're in our third version of our rat car. So we're in rat car three that we call rodent operated vehicles. Uh, they're a little smaller than a shoebox. And they have the tires and they have a steering mechanism that we had to figure out. And we use kind of old fashioned operant behavioral conditioning. Uh, with a fruit loop as the incentive, that's the currency of my lab. Uh, to, to shape them behaviorally to enter the car, to stay in the car, to press the lever and keep that lever pressed to activate and to drive the car to the fruit loop tree, which is their destination.

• 6:54Regina Barber?

  Okay, that seems like a lot of work, but you're saying these rats, they, they like this, they like driving, like, how do you know that? Is it from their brains? Is it from their behavior? Or is it like both?

• 7:05Speaker 02

  That's a really interesting question and probably the most popular question, frequent question that people have asked me, do they like it? And I can't give them a qualtric survey or something like that. So I can look at their behavior. When we bring them into the lab and to their driving arena, we transport them from their, from their transport cage into the car, they jump in automatically. So that suggests that they're at least approaching something and that's usually related to something they like. And as we're putting them into the driving arena before they even hit the rat road, they start activating the lever and it sounds like they're revving up the engine.

• 7:44Regina Barber?

  Yeah, I watched the videos. Um, I saw them like revving it up and really seemed like they were like so ready to go.

• 7:49Speaker 02

  Yeah, so approach is one way that a behavioral scientist like myself could understand that. I wanted to explore it a little bit more definitively, uh, with that small group. So they had only been able to access the fruit loop tree in their car in the past training. But I told, asked my students to let them get into the arena without the car and to see that they could clearly just walk down to that fruit loop tree. So the test and this preliminary- ...study was to put the car at one end of the arena as we always had done. The Fruit Loop tree was in the other end and we put the rat outside of the car just in the middle of the arena. So the most efficient way to get to the Fruit Loop would be to simply walk or run to the

• 8:34Speaker 02

  Fruit Loop tree, eat all the Fruit Loops you want. One rat consistently did this. We have individual differences with rats and I love that.

• 8:41Regina Barber?

  That's the smart one.

• 8:42Speaker 02

  Yeah. Two of the rats, they hesitated, they turned around, saw the car and not walk but kind of ran to the car, jumped in and drove to the Fruit Loop tree. Not once, not twice, but day after day, they are preferring to drive to the Fruit Loop tree as opposed to walk to it. That driving increased the anticipation.

• 9:04Regina Barber?

  Okay, I'm just gonna like pause you right there because I want to talk about this like anticipation because I know that there are these other studies out there indicating that there's like natural dopamine being released in these rats as they're like anticipating reward. It seems like you're like building on these studies. Can you explain how like driving fits into all that?

• 9:20Speaker 02

  Yeah, I developed a whole and with my colleagues, a whole new protocol looking at, I call it unpredictable positive experience responses. So at random times during the day, we're giving them these positive experiences so they never know when it's coming and then they have to wait for it. So I'm really trying to ramp up anticipation for something good. And we are starting to write up our initial data, but it's looking like we are indeed sculpting their brains differently, their behaviors, their vocalizations, whether or not they're happy or sad calls. And so if we think, if I think about my life, you know, if we're looking forward to a vacation

• 10:02Speaker 02

  with a family and you're thinking and planning, it's rare that the actual event meets all those expectations. So maybe the anticipation is even more rewarding than the actual event sometimes. But if we deprive ourselves of all that anticipation, we're really depriving our brains of a lot of feel-good chemicals and such. So the rats may be prolonging the feel-good time.

• 10:27Speaker 02

  The time that they're enjoying driving or anticipating that fruit loop.

• 10:32Regina Barber?

  Okay, so you mentioned that there are like physical like behavior cues that these rats are, they are experiencing this dopamine. Can you tell me a little bit?

• 10:39Speaker 02

  Yeah, again, it's exploratory, but just kind of blew my mind. So we were doing another test with these, we call them upper trained or positive anticipation trained rats where they were in an arena. And a student said, Dr. Lambert, why does the rat have its tail sticking straight up? And it was like an umbrella, you know, kind of a hook. And sure enough, the upper trained or anticipatory trained animals had it sticking up more. And I didn't know what this meant. So I put a picture on social media. I said, has anyone seen this? Because I just hadn't. And a few people said, oh, yes, if you inject morphine into a mouse or a rodent, their tail goes up. And I thought, have we, have we changed the,

• 11:22Speaker 02

  these opiates in these animals through behavioral training? So dopamine for pleasure and opiates for well being, that's a pretty good cocktail from behavioral training. And I've, I've introduced this word behavior, pseudicals that we can change our, so it was maybe the perfect behavior, pseudical, but we're still exploring. It's just great to watch the animals and they give you clues about what to look at next.

• 11:48Regina Barber?

  That's amazing. And I really like this like term that you've coined, this like behavior pseudicals, this idea that behaviors can alter your brain chemistry, which you're seeing, like similar to pharmaceuticals. How does this work with driving rats, like add to that line of research?

• 12:03Speaker 02

  Yeah, so we found that just going through the training itself, regardless if they learn to drive or not, that changed at least the, the hormone profiles.

• 12:14Regina Barber?

  Oh, so it doesn't even matter if they're a good driver or not. They just like driving.

• 12:17Speaker 02

  It's the process, journey, not the destination. Really. There's research to suggest that stress can impair neuroplasticity, or at least the healthier kind of versions of plasticity. So if this training is helping them regulate their emotions and have lower levels of stress hormones, that's going to have probably a positive impact on the, the brain. So if we know more about how we can intentionally and systematically

• 12:47Speaker 02

  Change our behavior to change our brains in healthy ways. Most of the research is related to changing neurochemistry through pharmaceuticals. But I wanted there to be more attention on the behavior. We know that cognitive behavioral therapy is very effective with humans, but we don't have good preclinical models. We're not sure exactly what that's doing. So I'm trying to replicate some of that with the animals so that we know more about what it's doing and that may elevate the respect for behavioral interventions.

• 13:20Regina Barber?

  Yeah, and neuroplasticity, as you're saying, is like the brain's ability to like change and learn, right? And so to sum up, like, training new skills helps these rats like regulate emotions, which lowers stress, which makes their neuroplasticity stronger, right? Like, it's a cycle.

• 13:36Speaker 02

  You got it, yeah. And this has lots of lessons. But now I'm excited about what we can learn from other animals. Rats don't represent all mammals, or all animals, or all brains. More research is done on mice now. It's convenient. We know a lot about how to house them and do research. But let's look at wild animals. Let's look at different... I love raccoons. They're out there working the environment and they're so smart.

• 13:59Regina Barber?

  They're so smart.

• 14:00Speaker 02

  We don't keep them in the lab, but they look like primate brains. There's a reason we can't invent or design a garbage can to keep them out. So I think there are a lot of species out there that hold a lot of secrets, that may unlock some mysteries about some of the illness, psychiatric and neurological illnesses that we face. So we need to diversify our research portfolios.

• 14:24Regina Barber?

  Wow. Aside from like what is scientifically proven and like how similar rats' brains are to human brains, what has this work done for you like personally? Has it changed how you look at life? How you look at anticipation and about delayed gratification and working for things?

• 14:42Speaker 02

  Yes, and on so many levels. A lot of research is focused on protecting children from trauma, and that's so important. We have adverse childhood experiences. We want to minimize the stress, the trauma. Little challenges are great, but horrible things that happen, that's so impactful for the brain, and we need to keep that up. But what about if a child has something to look forward to? While a pediatrician is asking about stressors in a child's life, I'd love to start thinking about the impact of asking, what are you looking forward to? Anticipation kicks in a lot of really healthy brain responses

• 15:23Speaker 02

  related to curiosity and planning and all that dopaminergic activity. So we need to balance the scale. And we've been a little one-sided, focusing on avoiding the negative. But we need to add to that to extend that anticipation like we're doing with the rats, where maybe they never know when something good is going to happen, or they know that they can wait and it's coming. That's also, I think, very healthy for brains. We're exploring it.

• 15:49Regina Barber?

  I love it. I'm going to take this and be like, you know, you can actually think that random good things are going to happen, too, not just bad things.

• 15:57Speaker 02

  That's not the way our culture is. It's just, what is the next bad thing that's going to happen?

• 16:01Regina Barber?

  Right. But now I'm going to be like your rats. I'm going to be like, one day, there'll be a Fruit Loop tree.

• 16:06Speaker 02

  Yes, yes.

• 16:08Regina Barber?

  Well, thank you so much for sharing your work with us.

• 16:11Speaker 02

  You're welcome. I love sharing our brain stories with anyone interested in hearing them.

• 16:17Regina Barber?

  This episode was produced by Hannah Chin. It was edited by our showrunner, Rebecca Ramirez. Tyler Jones checked the facts. James Keely was the audio engineer. Beth Donovan is our senior director, and Colin Campbell is our senior vice president of podcasting strategy. I'm Regina Barber. Thank you for listening to Short Wave from NPR.