The Null Device
Posts matching tags 'mice'
When testing drugs for treating depression on lab mice, it is important to have ways of determining whether or not a mouse is depressed, or suffering from the mouse equivalent of depression. Not surprisingly, mice deemed to be depressed are the ones which give up and stop struggling when faced with difficulty, and which get little joy from life:
Forced swimming test. The rat or mouse is placed into a cylinder partially filled with water from which escape is difficult. The longer it swims, the more actively it is trying to escape; if it stops swimming, this cessation is interpreted as depressionlike behavior, a kind of animal fatalism.
Sugar water preference. The preference an animal shows for sugar water is taken as an indication of its ability to derive pleasure, a quality that is missing in depression. Most rodents, when given two identical-looking sources of water, will drink much more of the sweetened water than the plain water. Rodents exposed to chronic stress or whose brains have been manipulated show no such preference.(Previously: Scientists create a mouse that's permanently happy.)
(via Boing Boing)
Scientists have developed mice which can regrow lost limbs or organs (or, in fact, everything other than brains).
Professor Heber-Katz made her discovery when she noticed the identification holes that scientists punch in the ears of experimental mice healed without any signs of scarring in the animals at her laboratory.
In one case the mice had their toes amputated -- but the digits grew back, complete with joints. In another test some of the tail was cut off, and this also regenerated. Then the researchers used a cryoprobe to freeze parts of the animals' hearts, and watched them grow back again. A similar phenomenon was observed when the optic nerve was severed and the liver partially destroyed.Not only that, but cells from the mutant mice, injected into ordinary mice, confer the regenerative ability, and it is believed that it may confer greater longevity. The genes in question are believed to exist in humans as well.
First a Brazilian artist commissioned a glow-in-the-dark rabbit, and now a biotech company is displaying fluorescent white mice at the Bio Taiwan 2003 expo. With photo, though whether they really look like that is debatable. (via jwz)