September 12, 2009

Scientists Levitate Mice

Scientists at NASA's Jet Propulsion Laboratory have now successfully used magnetic fields to levitate mice.

Researchers hope that the study of the mice, which are biologically closer to humans than previously floated live frogs and grasshoppers, will ultimately lead to advances in counteracting bone loss in astronauts caused by reduced gravity over long periods of time.

In an interview on Thursday, Jet Propulsion Laboratory physicist Yuanming Liu said that the mice were levitated by a no gravity simulating device powered by a superconducting gradient magnet.

Liu told Reuters, "The reason we want to levitate mice is we are aware of the situation that astronauts who stay in micro-gravity environments long enough might lose some bone mass."

"By levitating mice we can simulate similar conditions and we can study whether bone loss will actually occur in mice, and that will help us understand more about the bone loss that might occur in astronauts," he explained.

According to Liu, the next part of the experiment experimentation will involve observing the mice as they live in the levitator for at least a week to see how it affects them physically.

The superconducting magnet is able to generate a field powerful enough to levitate the water inside living animals. The space they are in is kept at room temperature in a large enough space measuring 2.6 inches wide, just big enough for the rodents to float comfortably throughout the experiments.

The first mouse to be used in the experiment was a three-week-old that weighed 10 grams. Initially, the tiny creature seemed agitated and disoriented and seemed to be looking for something to hold on to.
"It actually kicked around and started to spin, and without friction, it could spin faster and faster, and we think that made it even more disoriented," said Liu.

"Mice like to grab onto something and so by just floating in the air it's really different for (the mouse) to adjust to," he said.

An additional experiment was conducted with a partially sedated mouse that was remarkably calmer as he floated without gravity.

A paper published by Liu and his colleagues says that under repeated levitation, even the un-sedated mice acclimated to their new gravity-free environment in the cage and eventually began eating, drinking and acting normally.


On the Net: