Buff Mice

Se-Jin Lee from Johns Hopkins has made mice more muscular. (How's that for alliteration?)

It had been previously shown that mice engineered not to make myostatin are more muscular than normal mice. Mice that make extra follistatin also have big muscles. Dr. Lee generated double mutants, mice that make no mysotatin and extra follistatin. To his surprise, the effect was additive and the mice were even more muscular.

Understanding the molecular pathways that control muscle growth could lead to new treatments for muscular dystrophy. In fact, Dr. Lee's research was funded in part by the Muscular Dystrophy Association, Jerry Lewis's favorite charity. Good timing, Dr. Lee, since the telethon is this weekend!

You can read the original paper here.

The Spinning Mice are Loaded

OK, I think I finally managed to upload the video of The Spinning Mice.

Let me know if you can get it to work.

The accidental compulsive

Researchers at Duke University Medical Center may have stumbled upon a new mouse model for a human psychiatric disorder.

While studying how nerve cells connect and communicate with each other, the group, turned off a gene in the area of the brain called the striatum, which shuttles messages from the cerbral cortex to other parts of the brain.

Much as people with obsessive-compulsive disorder (OCD) may wash their hands repeatedly, the mutant mice groomed themselves incessantly, to the point where they injured themselves.

Some people with OCD are helped with selective seratonin reuptake inhibitors (of which Prozac is an example). When they gave the drugs to the mutant mice, the grooming stopped.

We have no way of knowing what these mice are thinking. ("Did I remember to turn off the stove? Maybe I didn't. I'd better go back and check again...and again...and again.") But it's a start.


Read the news story from Nature here and a story from Scientific American (with a photo of an overgroomed mouse) here .

Spinning Mice

I found this cartoon from 1935.



The live action part of the film shows what I believe to be actual
Japanese Waltzing Mice. The literature describes them as white with
black markings and their behavior also seems to match published
descriptions.

The cartoon version of one of the mice says "Nature intended me to spin
and I'm gonna leave well enough alone."

The cartoon tells the story about what is either a scientist or a
wizard (He wears a very Harry Potter hat). This guy transforms "ugly"
animals into "beautiful" ones. Lizards into doves, for example. Then
some new ingredient is accidentally added to the mix and it turns a
cage of spinning mice into devils who make a new potion and turn the
man into a giant rabbit.

The doves (that used to be lizards) save the day and make a new potion
that turns the man and mice back to ther original states. The man tears
up his book, singing:

"The knowledge in that book of mine
Is better left unknown
And as for this my motto is
Leave well enough alone."

So the lesson is that you can't/shouldn't improve on nature. Funny, it was
the "improved" lizard/doves that saved the day. And nobody bothered
to change them back into lizards.

The old song and dance

We've known about dancing mice for a long time. In the 19th century, Japanese Waltzing Mice were imported to Europe, to the delight of European mouse fanciers. The mice didn't really dance, but spun around nearly continuously due to an inner ear defect. It wasn't in 3/4 time, but it was a novelty and breeders continued to propagate the strain.

Japanese Waltzing Mice were important participants in nascent genetic studies of mice in the beginning of the 20th century.

Singing mice are new. Well, they've probably been singing all along, but we just haven't heard them. Male mice sing in the presence of female mice, but at a pitch too high for the human ear to hear.

Care to have a listen? Here's a little ditty. Here's something a little more operatic.

Three ways to make a schizophrenic mouse

One from the University of Texas
One from Johns Hopkins
One from MIT (Déjà vu! It's our old friend Susumu Tonegawa again.)

Fearless Mice

Scientists at the University of Iowa have produced fearless mice. Normal mice are fearful of open spaces, loud noises, and predators. (At least we think it's fear. They freeze.) But when the team, led by John Wemmie, disrupted the gene for an acid sensing ion channel protein (ASIC1a), the mice had reduced responses to the fearful stimuli.

Control mice froze when a beaker containing the scent of a fox was introduced into their environment. They stayed away from the beaker. Mice with the disrupted ASIC1a gene didn't freeze as much and even climbed onto the beaker. (Yes, they checked. Their sense of smell was normal.)

Now, these are lab mice. They have never seen (or smelled) a fox before. The researchers were studying innate (hard-wired) fear, not learned fear responses.

Here's the part that gets me. They also used a substance that blocked the ASIC1a protein (in normal mice). That also reduced the fear response. This substance, TcTx1, was isolated from the venom of Psalmopoeus cambridgei, this tarantula:



It grows to be five inches across, bigger than any mouse I've ever seen. I don't know about you, but no amount of spider venom will reduce my innate fear of this thing.