H20 IN A MARS METEORITE
Molten rock blasted from a Martian volcano many millions of years ago was relatively rich in water, according to MIT and Tennessee researchers. Timothy Grove, an MIT professor of earth, atmospheric and planetary sciences, and University of Tennessee geologist Harry McSweeny Jr., made the discovery while probing the Mars meteorite called Shergotty. The object, found in India in 1865, erupted on the Martian surface as a magma, and then hardened to solid rock. By studying the chemical make-up of crystals in the inter-planetary traveler, the researchers concluded the meteor must have been two percent water in its pre-volcanic life. “The only way you can reproduce the unique chemical composition of these crystals is to have water present,” says Grove. The work suggests a new explanation for the evidence pointing to the existence of water flows on Mars’ surface hundreds of millions of years ago. The liquid, the researchers say, may well have been brought up from underground via volcanic eruptions.
SWEET DREAMS, FIDO
Animals not only dream, they have complex dreams that often recapitulate major activities of their day. So reports MIT neuroscientist Matthew Wilson, who uses highly sophisticated monitoring technologies to map small segments of rats’ brain. Wilson probed the brain’s activation patterns both when the animals were running around a maze and during sleep. His specific focus was so-called rapid eye movement (REM) sleep — the phase of slumber associated with dreaming in humans. Roughly half the time, the patterns during the rodents’ REM sleep were like those during the maze tours. So close were the parallels that Wilson and his collaborator in this research effort, graduate student Kenway Louie, could tell “where” in the maze the animals’ dreams were taking them at a specific time.
HALTING WEIGHT GAIN
Researchers at the MIT-affiliated Whitehead Institute for Biomedical Research, working with a group of private-sector collaborators, have found the dieter’s dream: a substance that halts weight gain without requiring a change in diet. But so far, its effectiveness has only been proven in mice. “Much further research is needed to determine if this substance can be used as an aid in weight loss in humans,” says Harvey Lodish, a senior Whitehead staff member and a professor of biology at MIT. The substance is a chunk of a normal human protein. Dubbed gArcrp30, the partial protein was originally discovered by Lodish. In chubby mice fed a diet rich in fats and sugars — and allowed to eat all they wanted — the substance prevented weight gain. The researchers, who are from Genset Corp. as well as Whitehead, say the agent works by spurring muscles to burn fatty acids more rapidly than the body normally would. Lodish says that if the substance proves effective in humans as well as mice, it could offer a new approach to treating individuals affected by obesity.
Worms in which the effects of a specific, aging-related gene are enhanced can live half again as long as their normal counterparts, according to an MIT investigator. Leonard Guarente, professor of biology, had previously shown that this specific gene, called the silence information regulator 2 (SIR2), helps slow aging in yeast. In an experiment with what’s known as the ordinary round worm, Guarente and his co-workers put extra genes, including SIR2, in larvae. “Lo and behold, the worms with the extra section lived extraordinarily long,” he says — three weeks instead of the usual two. The scientist says the effect may reflect the impact of the gene’s protein products on the worms’ insulin pathways. Insulin, a hormone linked to diabetes, helps control the way the body handles carbohydrates. That connection in turn points to likely associations between Guarente’s experiments and the fact that sharply cutting caloric intake has been found to lengthen life spans in a wide range of organisms.