SIU, home of the Salukis and naked mole rats

Jared Treece @bisalo

Naked mole rats at the labs in the Life Science III building are used for research purposes on Wednesday, Jan. 22, 2020 on the SIU campus.

By Kallie Cox, News Editor

Attention, Salukis — naked mole rats may steal the show at the university. 

SIUC houses over 60 naked mole rats in Life Science III.  

Diana Sarko, an assistant professor with SIU’s school of medicine, runs the lab with graduate student Natalee Hite. The animals are used for research at the university and the School of Medicine. University research includes studying tooth loss and the animal’s special neuromuscular adaptations. 

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“[Naked mole rats] are used for studies of denticians looking at tooth representations and tooth loss and that’s where we got especially interested in them here in terms of that as a critical U.S. health issue,” Sarko said.

Sarko has been researching naked mole rats since her post doctorate  at Vanderbilt University and she became interested in comparative neurobiology and sensory specializations. 

Now, Sarko and Hite are researching naked mole rats in terms of health issues and are studying their bite force and various neuromuscular adaptations. 

Naked mole rats are becoming more popular in medical research because they have much longer life spans than the average lab rat, the typical lab rat will live around two to four years whereas a naked mole rat can live upwards of 30 Hite said. 

“Because these animals live to be so old comparatively, there’s this possibility for these longitudinal studies where we can really follow and see what happens in these much older animals which would be much more [like] what happens in people,” Sarko said. 

Their current project is creating a system where they can consistently hear neural recordings and see the animal’s responses to stimuli. This is to find the area of their brain that responds to tooth sensations.

Knowing that location in the animal’s brain enables the researchers to study how sensations can be compared and analyzed, Hite said.

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“With tooth loss being our focus, if we understand how the teeth respond to those paired sensations then if we were to extract a tooth and study how the brain is able to […] modify itself after that tooth extraction, we can further understand how tooth loss would affect humans,” she said. 

The researchers are interested in seeing how neural activity correlates with real-world behaviors and neural trajectories to see how different brain projections change following tooth loss, Sarko said. 

Since tooth loss tends to happen with age and disease, Sarko said using naked mole rats to research tooth loss would be much more applicable to modeling human studies. 

Naked mole rats are also a great model for emerging cancer studies because of their long life spans, Sarko said.

While SIUC is not currently using the animals for cancer research specifically, Sarko is hopeful they can participate in those studies in the future. 

“We have such a big colony we are hoping, that at some point with some of the strong cancer research that’s going on at SIU up in Springfield, and so on that eventually these animals can be useful in some sort of collaborative capacity,” Sarko said. 

One of Hite and Sarko’s most recent discoveries is how a naked mole rat’s bite force correlates with social status in the species’ colonies. 

Naked mole rat colonies are similar to bee colonies.

Both have a queen that is responsible for giving birth and this is classified as a dominant animal, Hite said. 

In their research on bite force, Hite and Sarko found subordinate animals’ bite is stronger and they had a shorter bite latency than the dominant ones within the colony.

Hite said this difference in bite latency and force could be the subordinate rats have a more diverse range of roles. They are the defenders of the colony, and would have to react faster to threats.

Naked mole rats can bite harder than a bear, Sarko said. She said this is surprising because usually, the larger an animal is the stronger its bite, and naked mole rats to be an exception to the rule. 

“They were stronger than any other [animal] we compared them to and it was somewhat comparable to a Tasmanian devil,” Sarko said. “So we say they’re like little Tasmanian devils but much stronger than humans.”

If they were human-sized, they’d bite approximately 40% harder than people are capable of biting, Hite said.

In general, naked mole rats are docile and avoid fighting, but when they do fight they do something called “incisor fencing,” Sarko said.

This looks like sword fighting, but with their teeth.

Sarko said there was a violent incident early on that led to fighting within the colonies and because of this, the queens of the two colonies are named Cersei and Daenerys after the warring queens in Game of Thrones. 

“Part of that is due to the fact that one queen was usurped by another animal and we found that queen dead with her head sort of gouged out and she had been left in the toilet chamber,” Sarko said. “It was very cold-blooded and a new queen emerged and so there was fighting with that.”

Usually, you see various sorts of little spats but generally not anything where animals are injured, Sarko said. 

“Once they establish their hierarchy, in general, it’s very stable and I never in my career of working with these guys had I seen a queen overthrown,” Sarko said. “She might have been in a bit of a weakened state; she had just had pups and she may have had a bit of illness that we weren’t able to detect or something like that.”

Hite said one of her favorite facts about naked mole rats is that when a queen is pregnant, she releases hormones in her feces and this is how she recruits babysitters for the new pups. 

“The other naked mole rats will eat her feces and due to the hormones in that, it will cause some changes in them so that it will make them babysitters when these babies are born,” Hite said. “The more hormonal poop they eat from the pregnant queen, the better babysitters they are.”

Sarko said her favorite fact is that the rats are very resistant to pain.

“There was a study that was recently done that showed they could be deprived of oxygen for upwards of 18 minutes and they went into a sort of a plant-like state where they were processing things differently and then they could come back from that as well,” she said. 

News Editor Kallie Cox can be reached at [email protected] or on Twitter at @KallieECox.

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