Stories tagged mice

Preble's meadow jumping mouse: Preble's meadow jumping mouse.  Photo courtesy U.S. Fish and Wildlife Service.
Preble's meadow jumping mouse: Preble's meadow jumping mouse. Photo courtesy U.S. Fish and Wildlife Service.
A while back I blogged about the Preble’s meadow jumping mouse and its possible removal from the endangered species list. The designation would play a role in the development that could take place in the mouse's habitat. Well, the little fellow is in the news again, with the designation of wildlife areas as critical habitat for the Preble’s meadow jumping mouse. Good luck little fella!

Dot race
Dot raceCourtesy American Chemical Society
Scientists are always trying to run lab rats through mazes right? Well, maybe not as much as we see in TV and movies, but these scientists took the same task and bested the mice....with chemistry. Chemists at Northwestern University developed a maze, filled it with a basic solution, and were able to get a gelatinous chunk of acid to navigate its way to the solution. Find out how. The movies are pretty cool to watch.

Sep
10
2009

Pshhhheeeewww!: Science everywhere!
Pshhhheeeewww!: Science everywhere!Courtesy SiamEye
I don’t even know where to begin today! All I can think is “OMG!!!!” And each exclamation point I think is like a blood vessel bursting in my brain!

OMG pop pop pop

So why is this a day of excitement, instead of quiet family tragedy? Because the biggest explosions today aren’t happening in little tubes in my head, they’re happening in the world of science! (I don’t consider the physiology of my head to be science. More like magic. Or trial and error.) I just don’t know what to do with all this science.

See, unlike your average Friday Extravaganza, a Thursday Explosion has no focus; it’s just kind of all over the place. A mess! There are all these stories, but we really have to stretch to fit them into a single post… so the loose theme of this explosion will, fittingly, be “flying things.” Am I not helping? Just wait, you’ll see.

Normal mouse becomes flying mouse, doesn’t care!
Check it out: a baby mouse was put into a little chamber and subjected to an intense magnetic field. What happened? All the water in the mouse’s body was levitated. And because those squishy little mice are so full of water, the mouse itself levitated along with the water.

Unfortunately, the first mouse wasn’t quite ready for life as an aviator, and upon levitation, he began to, as scientists say, “flip his Schmidt.” Lil’ mousey started kicking, and spinning, and with minimal resistance in the chamber, he started spinning faster and faster. He was removed from the machine, and put wherever little mice go to relax. Subsequent floating mice were given a mild sedative before flying (pretty much the same thing my mom does), and they seemed cool with it. Now and again the floating mice would drift out of the region of the magnetic field, but upon falling back into it they’d float right back up. After remaining in a levitating state for several hours, the mice got used to it, and even ate and drank normally. Afterwards, the mice had no apparent ill-effects from the experiment (rats had previously been made to live in non-levitating magnetic fields for 10 weeks, and they seemed fine too.)

Aside from the excitement normally associated with floating mice, the experiment is promising in that it may be a useful way to study the effects of long term exposure to microgravity without bringing a subject to space.
pop pop pop

Great tits are dangerous if you’re a sleepy bat!

It’s true! Forget everything you thought you knew about great tits and get schooled once again, my friends, for great tits are killers!

I’m not talking about the senseless murder of bugs, either—everybody already knew that great tits are primarily insectivores. A population of great tits in Hungary have been observed hunting bats!

As fun as it is to keep writing “great tits” with no explanation, I suppose we should be clear that great tits are a type of song bird common in Europe and Asia. Little, bat-hunting songbirds.

Meat eating great tits had been reported in other parts of Europe, but it was thought that those individuals had only consumed already-dead animals. The tits of Hungary were actually observed flying into bat caves, where they would capture tiny, hibernating pipistrelle bats and drag them out of the cave to devour them alive. It even appeared that the birds had learned to listen for the bats’ disturbed squeaking (or, as I like to think of it, their horrified shrieking)—when the same noise (which is too high for humans to hear) was played back for captured tits, 80% of the birds became interested (read: bloodthirsty) at the sound.

If it really is just the Hungarian population that engages in this behavior, the situation also brings up the possibility of culture in the birds. That is, if this isn’t some sort of innate behavior, but something learned and taught, and passed through generations that way, it could be considered culture. Amazing! Great tits are cultured!

pop pop pop

Flying velociraptors!

Well, not so much flying as falling. But falling with purpose. (What was it Buzz Lightyear said? Oh yeah, “I’m so lonely all the time.”)

We all know about how awesome raptors are. I think it’s part of kindergarten curriculum now, just between how not to accidentally poison yourself, and why you shouldn’t swear and hit. Well, I remember reading a news item a couple years ago about how some paleontologists were thinking that raptors’ famous giant toe claws may not have been for disemboweling their prey. Instead, the scientists proposed, raptors would lodge the massive claw into the skin of their prey with a kick, and then use it to hang on to the unlucky animal while the raptor went bite-crazy. The researchers had made a simulation of a raptor claw, and found that it could easily puncture thick skin and flesh, it didn’t seem to be sharp enough to actually cut the skin. (Cutting is necessary for a good disemboweling.) One might argue over the strength and sharpness of raptor claws, considering that the fossilized bone claws we see in museums would have been covered with a tough, horny substance, which did not fossilize, but whatever—the new scenario was still pretty cool.

Now, the same group of paleontologists is proposing that raptor claws were also well suited to tree climbing. Raptors could have waited on overhanging limbs, and then pounced on their prey from above. Pretty neat! The researchers point out that the microraptor a tiny relative of the velociraptor, had feathered limbs to help it glide down from high places, so it’s not a stretch to think that its cousins were comfortable in trees too. “The leg and tail musculature,” one scientist says, “show that these animals are adapted for climbing rather than running.”

I’ll take his word for it, I guess, but I do have some questions on that point. There’s a dromaeosaur (it looks a lot like a velociraptor) skeleton here at the museum, and I seem to remember that its tale was supposed to be very stiff—it has these cartilage rods running the length of the tail to keep it rigid. I feel like a long, stiff tail would be a pain in the butt up in a tree. It’s not the sort of thing arboreal animals invest in these days. Also, I wonder what sort of vegetation was around in the areas raptors lived. Plenty of big trees with good, raptor-supporting limbs? (I’m not implying that there weren’t, I’m just curious.)

The researchers do acknowledge that tree climbing wouldn’t have been every raptor’s cup of tea, however. Species like the utahraptor, weighing many hundreds of pounds, and measuring about 20 feet in length would have been “hard put to find a tree they could climb.”

pop pop pop

Pretty neat stuff, huh? Explosions usually are. But you see now why I couldn’t wait for three posts to get it all out there.

Oct
01
2008

Cute, nautical, and Scandinavian: But probably smaller.
Cute, nautical, and Scandinavian: But probably smaller.Courtesy hans s
So… we’re learning about genetics, aren’t we? We can’t help it—here we have see-through frogs, there we have genetically engineered vegetables, here we have a fatherless child with the same hair color, eye color, and blood type as me. Genetics are all around us these days, in our schools, in our dinners, and calling our lawyers. As much as we might try to hide from it, the subject is unavoidable.

It’s nice, then, when some aspect of this genetic tsunami can take our minds off of all the tricky stuff. Things like mutant frogs are fun (All those legs! Somebody give them their own cartoon!), but they never last long (The frogs tend to die. Cancel the frog show.)

I think, however, that I may have found a winner: Viking mice. They’re genetically remarkable, and they’re lifespan is the same as any other mouse: about 2 or 3 years. Somebody start work on a Viking Mouse cartoon!

So what we have here is your common house mouse. The house mouse evolved into a variety of different strains as it spread into Western Europe about 3,000 years ago, during the Iron Age. Little French house mice learned to wear berets and smoke cigarettes, German mice developed a love of sausages and efficiency, and so forth; the Iron Age was a wonderful time, and it birthed many of our favorite cultural stereotypes. However, something interesting has come up in a recent genetic study of British house mice.

The surprising result of a nationwide rash of mouse paternity cases, the mice of Britain were surprised to find that they themselves were the products of unexpected parents. Studying their mitochondrial DNA (traceable genetic material from the mother’s side), it appears that most mice from mainland Britain are closely related to mice from Germany (the descendants of little Saxon mice?). Mice from the Orkney Islands of Northern Scotland, however, were found to be “Viking mice,” genetically similar to mice from Norway. And it makes sense—the Orkneys were an important center of the Norwegian Viking “kingdom,” back in the 11th and 12th centuries. These little mousies are the descendants of the warlike Viking mice, who hitched rides across the North Sea in the holds of Viking longboats a thousand years ago. Or… maybe they had their own tiny boats… Viking mice!

We pretty much already knew that Vikings were in the Orkneys at that time, but the genetic evidence from the mice are is a good example of how non-human DNA (mitochondrial DNA in particular) can be a tool for tracking other historical human migrations, and… and…

Just picture those little Viking mice. Tiny helmets, curly little beards, squeaky battle cries… they must have been adorable. Just to see them slaughtering little monk mice, it must have been too cute.

Oh, also, while we’re on the subject of house mice—I noticed this little section in Wikipedia’s article on them. After being accidentally introduced to the south Atlantic Gough Island, house mice, which normally have a body length of about 3 inches, began growing “unusually large” and feeding on albatross chicks. The mice kill the chicks, which can be about a meter tall, by “working in groups and gnawing on them until the bleed to death.” Talk about Viking mice.

Mar
17
2008

The mouse knows why: But she's not telling.
The mouse knows why: But she's not telling.Courtesy d ha rm e sh
News broke this week that the Kremlin guard—the security service of the Russian government—has been looking to acquire 3,200 female mice.

Why? They aren’t saying. “If [the mice] were ordered then that means they are needed,” was all a Kremlin guard official would reveal. That, at least, is a relief. I’d hate to think what they’d do with all those mice if they didn’t need them.

Some Russia/mice enthusiasts guess that the mice may be intended for feeding the Kremlin’s falcons, which are kept to scare off crows from the government seat. Others think that the rodents will be used to test toxic chemicals, or as indicators for the presence of dangerous gases. I am inclined to believe that the Kremlin is simply attempting to corner the world mouse market.

It was revealed Friday that the Kremlin has already found a mouse supplier, and will be paying approximately $20,000 for the rodents.

Strange plans are afoot, Buzzketeers. Any thoughts on just what they might be?

Jun
27
2007

Have you ever wondered why medicine seems to be so ineffective in dealing with many neurological diseases? We have treatments and drugs to combat disorders throughout the rest of the body, but diseases like Alzheimer’s or Parkinson’s remain difficult to treat.

A team of scientists recently created a drug that can cross the blood-brain barrier to treat neurological diseases in mice. Capillary walls in the brain are very effective at controlling which molecules can pass into the spaces between neurons. This protects the brain from potentially harmful chemicals in the blood. Until now, this also prevented much needed medicines from penetrating into an affected brain!

But, wait. If the brain is so great at preventing molecules from penetrating capillary walls, how do diseases get through? Some viruses, such as rabies, are able to trick the barrier into letting them through. Researches attached one of these trickster molecules from rabies onto a drug, and found that the drug was delivered through the capillary wall and into the brain.

In this study, scientists infected mice with Japanese encephalitis. Medicine delivered using the new method kept 80 percent of diseased mice alive for 30 days, while all of the untreated mice died.

While researchers tested this technique only on mice, soon this could provide huge benefits to humans. The drug used to combat encephalitis in mice uses a kind of RNA, short-interfering RNAs (siRNAs), that block the activity of a gene. This type of RNA can be custom tailored to target almost any disease-causing gene or protein. Combined with the molecules that can break through the blood-brain barrier, scientists could more effectively treat Alzheimer’s, Huntington’s, Parkinson’s and many more neurological diseases.

Jun
02
2007

Walt Disney’s dream has finally become nightmare-reality.
I don’t think that statement needs any clarification, but for those of you who are unwilling to accept what’s in front of your very eyes, let me lay things on the line: Scientists from Texas (of course!) have genetically engineered super mice.
Our Only Defence: Keep these close at hand. They may be our only hope. (photo credit to billselak)
Our Only Defence: Keep these close at hand. They may be our only hope. (photo credit to billselak)

What are coming to be known as the “six million dollar mice” (and I can not confirm that price tag, only that they are indeed as cute as the original six million dollar creation, if significantly smaller than Lee Majors) were created by the genetic deletion of the enzyme “Cdk5” from their mousy brains. This causes “an increase in sensitivity to their surroundings” which “seems to have made [the mice] smarter.”

The smart-mice have become more adept at learning to navigate through mazes, and working out new routes as the mazes change. They also are able to quickly learn that “being in certain boxes involves a mild shock.” These are things that I can’t even do, and I have a degree in English.

As horrifying as the prospect of a genius mouse may be, the Texan scientists are quick to point out aspects of their research that will likely be beneficial to human health and psychology.

The technique used to suppress the Cdk5 enzyme works at the genetic level, and is referred to as “conditional knockout.” It allows scientists to eliminate the gene only in the brain, and only once the subject is an adult, as opposed to the older and less sophisticated “traditional knockout,” which eliminates the gene entirely.

This sort of therapy might be used to help people suffering from conditions such as post-traumatic stress disorder “learn that a once-threatening situation no longer poses a danger.” Also, Cdk5 seems to be associated with drug addiction and Alzheimer’s disease, and the researchers are hopeful that the study might lead to further treatments for these and other conditions.

So, we may not be doomed to some kind of Mickey Mouse/Bladerunner-esque future after all, but, still, I’ll be keeping my eyes and puny human brain trained on this one.

An article about the smart mice

Feb
15
2006


Lab rat: A brown lab rat in a cage, poking it's nose out between the bars -- ooh, it's sooooo cute!

A new study suggests that our brains learn by replaying events in reverse.

In a lab experiment, mice were taught a new task. Researchers recorded their brain activity. After the task, they found the nerve cells active in learning the task fired again, but in reverse order. Scientists suspect the brain is trying to reinforce the activities closest to the successful completion of the task.

Human brains and rat brains have some strong similarities, so this may lead to a new understanding of human learning. For instance, researchers have long known that cramming right before a test generally doesn't help—the brain needs time to absorb the new knowledge. If the "running in reverse" pattern holds true in humans, then the best approach may be to take frequent breaks to allow our brains to review the material.

Hmm, I wonder if my boss will buy that? "I wasn't goofing off playing Solitaire! I was giving my brain a chance to replay my new knowledge!"

Jan
26
2006

Preble's meadow jumping mouse: Preble's meadow jumping mouse.  Photo courtesy U.S. Fish and Wildlife Service.
Preble's meadow jumping mouse: Preble's meadow jumping mouse. Photo courtesy U.S. Fish and Wildlife Service.

This little fellow, the Preble's meadow jumping mouse (Zapus hudsonius preblei) is causing quite a stir. Almost a year ago, Interior Secretary Gale Norton suggested removing the bouncing rodent from the endangered species list. She based her suggestion on a study done by a biologist hired by Norton's department that showed there was no genetic difference between the Preble's meadow jumping mouse and the much more common Bear Lodge meadow jumping mouse. However, in a recent United States Geological Survey report geneticists found that the mouse was, in fact, a distinct subspecies.

The Fish and Wildlife Service said the new study results raise significant questions about the previous study, and that it will convene a panel and study the mouse for at least six months before deciding on its status.

If the mouse were removed from the endangered species list a large section of Colorado and Wyoming, which is identified as critical habitat to be conserved for the recovery of the mouse, would be available for new development.

The Preble's meadow jumping mouse is capable of jumping 18 inches into the air and can change direction in mid jump. It can leap distances up to three feet, and also can swim. The mice are hibernating now, but when they wake up I'm sure this will be a huge relief.