So how do we go about finding out what cells in a part of the brain uh do um in rodents ? Well um for many years now we and many many others have been using the following techniques. Um what we do iswe place electrodes into uh a part of the structure under deep anesthesia
This is a mouse. This is a rodent that has a mutant circadian clock. It becomes obese. It develops the features of diabetes.
roof workmen on the site discovered human bones in those walls bones of small children and an old woman from the crushed skeleton of a rodent no biologist could place what an interesting way of contemplating movement through time and SP face I'd not considered that before in my studies
Yes. It's a furry rodent . And with the rodent , you got it right.
It's a furry rodent . And with the rodent , you got it right. I mean, it's a close cousin of the thing that scampers away from the garbage cans when you go look out behind the restaurant.
And there's only 200 inspectors at City Hall. Is there complaints of rodent infestation?
It becomes obese. It develops the features of diabetes. And these two rodents are actually twins. I guess there were a bunch of them, so I don't know what you call two of a group of a whole bunch of them.
But Jobs realized, you know what, it's not enough to just put people in the same building, we need to force them to mix and mingle. You see this is rodents and you see this in humans.
And we examined them using as close an exam to the rodent exam as I could develop. So I tried to mimic the rodent study. So I said, here's what I looked at in the rodent .
But it's the human physiology and the biology that I think is really interesting, because those are things that can help us down here on Earth. And part of that is rodent research. This is an example of some of the rodent facilities that we had.
the construction of a building, and the ultimate structure closely resembles the scaffolding that was once present. So we turn again to the rodent literature because the rodent literature is much more advanced in addressing these questions about the intimate relationship between the parent and the development of the amygdala.
One long, giant lung and one smaller lung. They will also listen for rodents underground and time their pounce just right to grab that rodent as it comes up from underground.
The idea is that there's areas in the brains of most mammals that allow them to navigate and understand space, in a manner of speaking. And the second to a rodent .
And there's only 200 inspectors at City Hall. So you find out the number of rodent complaints.
tell you about how we think humans navigate and then I'll tell you about what we know about uh the areas of the brain mostly from work on on rodents uh which are involved in in this in this task. Let me start with a a simple navigational problem. Um it's it's based
We got everybody who would bring their child in. And we examined them using as close an exam to the rodent exam as I could develop. So I tried to mimic the rodent study.
And part of that is rodent research. This is an example of some of the rodent facilities that we had. And I'm working with my crewmate Scott Kelly there.
So we've looked very closely at the role of early experiences in childhood on the development of emotions and neurobiology. And we're really motivated by a number of rodent studies that have shown that stimuli that are learned, or things that we're exposed to early in life, can actually endure into maturity.
And in children, we see that the amygdala decreases its activity in response to the parent cue. So this is consistent at least with the rodent data, showing that parents are effective in buffering overactivity of the amygdala in their children.
So one of the things that we learned about 20 or 30 years ago is that if you don't sleep you die. And this was research that was done in animals-- in rodents -- and a rodent that is sleep deprived completely will eventually die. And they die what I would call a metabolic death.
So in a lot of ways, for the cats, it's like oh, I notice your warehouse is rodent -free. Perhaps you would like it to continue to be rodent -free. Perhaps there will be cream waiting for us every Thursday at 3:00.
the time there was some storm, some little bit of the coastline and you ripped out, it would go out in the water, nothing would come of it. But maybe every once in a while there would be a Hail Mary play and that raft of vegetation carrying these monkeys and these rodents would reach thousands of miles away and they would have a new shoreline to colonize. And that is what happened and I think it is one of the most incredible stories of evolution. We wouldn't know about it if we didn't have the genetics and the fossils together to tell us that story. After the asteroid hit,
You will pick out the person in the audience probably who's eating the cuy there and kind of holding it up. So anyway, cuy are rodents , and they're not strictly legal here in the United States. So supposedly I had to figure out whether the cuy were coming in suitcases with immigrants, or whether people were actually ranching the cuy somewhere
And what he did, by doing this, is he started to nourish all of those microbes and all of those worms and all of those voles, the little rodents that live under the soil which are there to process that organic matter. And in turn, these billions of unpaid workers began to nourish his plants.
Voila, you've turned a relationship of violent inequality into a relation where the victims are running around feeling inadequate all the time, making terrible apologies for themselves if you have idle grain and it gets eaten by rodents and slowly diminished and rots -- David Graeber: Um-hum.
showed you before there have been many studies where you take a rodent that has some problem say uh obesity diabetes
scores a touchdown. The odds of success are very low because the pass is so long, but every once in a while, that pass connects. And your team wins the game. We see this with migrations. There are mammals in South America today, both primates and rodents . So the classic monkeys, the howler monkeys of South America, and some of the classic rodents of South America guinea pigs, capybara. They've been there for a long time. How did they get there? Nobody really knew South America was an island continent for many tens of millions of years. How did these mammals make their way? They
So it looks as though, in rodents , the infection by the parasite changes their behavior.
our Behavior there have been many studies in mice in some of those germfree rodents I showed you before showing that the microbes that live in
Leopards could live on small birds, rodents if they had to, where a tiger never could eat anything smaller than pretty much a wild boar
and there's a lot of food available, the rodent population goes crazy.
So I tried to mimic the rodent study. So I said, here's what I looked at in the rodent . Here's what I'm going to look at in the baby.
They are a bit different than our North American species, of course. But to give you some quick fun facts, they are a rodent , so that means their front teeth are always growing, the incisors are always growing. And they can bring food to their mouth with their front feet.
it looks like it has the same structure. So, you you can look at it in a in a in a rodent or in a in a primate or or in human beings, and it has the same structure. And we know quite a bit uh about the detailed structure of it. I
sensitive to it. It's sort of how you would imagine an old rodent cage smelling.
So 100 million years ago, these mammals emerged, rodent -like creatures with a neocortex that was the size of a postage stamp, about as thin as a postage stamp, flat and
couldn't fly, they couldn't swim, they couldn't jump between land bridges. How in the world could they get there? Well, the answer started to become really clear with the genetics of those mammals. It is clear from doing the DNA paternity test that they are closely related to African rodents and primates. Okay, so how do African rodents and primates get to South America? Well, it seems like the only way is through one of these Hail Mary dispersals where there are some of these mammals,
It is clear from doing the DNA paternity test that they are closely related to African rodents and primates. Okay, so how do African rodents and primates get to South America? Well, it seems like the only way is through one of these Hail Mary dispersals where there are some of these mammals, maybe after a storm, maybe they're on a raft of vegetation, sometimes big chunks of the coast, trees and grass and all kinds of stuff can be ripped apart, thrust out into the ocean, and
Because, you know, our ancestors were just little basically rodents , rats living under the footsteps of the dinosaurs.
micros throughout their entire lives to build and shape their bodies and we know this because of rodents like this one
and the hot weather animals live in Sahara Square, and the mice characters live in Little Rodentia.
Could be your dog, your cat-- anything-- and it's going-- could be rodents .
- Their primary sources of food would be monkeys, turtles, turtle eggs, and small game like paca, the large rodent that's the size of a beagle.
Importantly, this effect was not observed in adolescents, who showed a beautiful cortisol response regardless of who they were sitting next to. So we were also interested in this parental buffering effect, but we wanted to return to that rodent study and see if learning that fear conditioning paradigm worked the same way in humans.
And they can't really ignore them, because the cats have opposable thumbs and matches. So in a lot of ways, for the cats, it's like oh, I notice your warehouse is rodent -free. Perhaps you would like it to continue to be rodent -free.
Intermittent reinforcement-- will press the lever for food, will hit mouse for food-- mouse, rodent , rat.
"Blame it on Chavez. The Easter dish of choice in Venezuela is the capybara. An oversized rodent , cousin to the guinea
change. And what happened was it seems like it triggered this mass migration of mammals. Now, a whole lot of the world could be traversed. The high latitudes, they were free of ice. It was easy to move around. So mammals were on the move, and that unsettled things. And from there, this new reality emerged where modern primates, rodents , hoofed mammals, they become dominant at that time. And a lot of these more archaic mammals, these ancestors, they sputter away to extinction. And
And a lot of these more archaic mammals, these ancestors, they sputter away to extinction. And since that time, it has been those mammals, primates, rodents , hoofed mammals like cattle or horses or rhinos. And then later on, bats and whales and so on, it's those mammals that are the preeminent ones today. And it's largely because of that spasm of climate change that helped them take over the world. Mammals move. Many animals move. That's really the story of Earth history,
maybe after a storm, maybe they're on a raft of vegetation, sometimes big chunks of the coast, trees and grass and all kinds of stuff can be ripped apart, thrust out into the ocean, and can actually travel the currents for many weeks and then land somewhere in a distant land. And that seems to be how the rodents and the primates got to South America. And it seems inconceivable how in the world could they survive a voyage like that. But we have to remember that evolution has lots of time to work with. And if you're talking about many, many, many millions of years, most of