Molecular memory
Using a protein normally found in mammals, U.S. researchers have created a fruit fly with an exceptionally long memory.
A person’s memories are encoded in synapses, which are the connections between brain cells. When memories are reinforced—by exam-time cramming, for example—these synaptic connections are strengthened.
The mechanics of this strengthening process have remained a mystery.
Researchers at Cold Spring Harbor Laboratories in New York created genetically engineered fruit flies that expressed a mouse enzyme called PKM. The flies were placed in a maze in which an electric shock discouraged them from taking a particular route. Non-engineered flies remembered about the shock for about 24 hours. But the engineered flies held on to the memory well into the next day.
The fact that mouse PKM enzyme can heighten memories in flies strengthens the idea that many genes have changed very little over the course of evolution.
Easter for losers!
Spinning a hard-boiled egg on a flat surface yields a surprising result: as it spins, the egg will slowly rise up on one end, apparently defying gravity.
An object that’s rapidly spinning will keep on going in the same direction—the reason a bicycle doesn’t topple over. But when an egg is spun, friction between the shell and the tabletop throws this directional conservation out of whack.
Although an egg will start to spin horizontally, any irregularities in the smoothness of the shell will cause it to slide.
To counteract the slippage, a frictional force is created that pushes the egg up, up and up—until it’s almost spinning vertically. For some inexplicable reason, a group of eggheads (Ha! The wit!) has come up with a bunch of equations to explain the whole phenomenon. If you’re even more of a geek than those guys, check out http://www-hotz.cs.uni-sb.de/silvia/elli/elli.html for a spinning egg simulation.
And for more information, and possibly, recipes, e-mail editor Paul Tadich at [email protected]
