Dec. 18, 2002 -- It was finals week at the University of Illinois when biology major Peggy Gatsinos got a clear sign she was running short on sleep.

After breakfast, she explains, "I went to put the things away and I put the cereal in the refrigerator and the milk in the cabinet."

For reasons that scientists don't yet understand, sleep is critical for normal functioning of the human brain. If we skimp on it, we start making mistakes — from putting cereal in the refrigerator to falling asleep at the wheel.

Soldiers that Never Stop

Lack of sleep has been blamed for a number of infamous mishaps from the Chernobyl meltdown to the space shuttle Challenger disaster.

It's a problem that the military takes a keen interest in, since whether or not troops get their zzz's can determine the outcome of a battle. By devising superhuman ways of staying awake for up to seven straight days and nights, military officials hope to lend U.S. soldiers a strategic edge in future conflicts.

"Eliminating the need for sleep during an operation … will create a fundamental change in war fighting and force employment," says a recent statement by the U.S. Defense Advanced Research Projects Agency.

To strive toward creating the no-sleep soldier, DARPA has funded a multi-tiered program from tinkering with a soldier's brain using magnetic resonance to analyzing the neural circuits of birds that stay awake for days during migration. The hope is to stump the body's need for sleep — at least temporarily.

"This program is really out of the box," says John Carney, director of DARPA's Continuous Assisted Performance program. "We want to look at capabilities in nature and leverage it so we can apply it in ways that no one thought possible."

No-Sleep Masters: Dolphins and Sparrows

One of the first places scientists are looking for answers is in other species.

Dolphins, for example, live in water and need to stay awake at all hours in order to breathe. To do this, it's believed the animals keep parts of their brain awake while other parts sleep. This allows them to stay alert and get to the surface regularly to breathe.

The Navy's Marine Mammals Program, set up primarily to train dolphins and sea lions to do underwater searches, is conducting PET (positron emission tomography) scans on the animals to try to learn more about their unusual ability. It's also doing behavioral studies on orca whales since in the first three to four weeks after birth, newborn orcas and their mothers appear to stay completely active.

"The first stage is to confirm these abilities exist," says Carney. "Then maybe we can begin applying it to humans."

Niels Rattenborg, meanwhile, is tapping the brains of tiny birds to find answers.

Even when kept in a cage, white crown sparrows don't sleep during the time they would normally be winging thousands of miles in their biannual migration from Alaska to California and back again.

"This bird will spontaneously start to hop around its cage when it would be migrating," says Rattenborg. "At the most during these periods they occasionally get drowsy, but they never get any real sleep."

Rattenborg, under the guidance of Ruth Benca, both of the University of Wisconsin, are attaching small sensors to the sparrows' brains to monitor their brain activity during the five to seven days and nights the birds stay awake. They're also testing the birds' cognitive abilities during the sleepless stints.

"Our preliminary results suggest they don't show any deficits when they're doing this," says Rattenborg.

Part of their work is in understanding how the birds prepare for their days without sleep. He says they've noticed the sparrows appear to put on significant weight just before their migration periods.

"We think the increase in food may be due in part to the flying," says Benca. "But it may also be due to an increased metabolism."

Gene Tinkering

Of course, simply understanding how some animals can go for long periods without sleeping is only the first step. The next — finding ways to apply their abilities to people — is likely the bigger challenge.

One way is through genetics. As Carney points out, the human genome is full of genes whose purposes remain mysterious to scientists. Some so-called junk DNA may not play a role in people, but could trigger important functions in other animals.

"The other animals may be using them," said Carney. "If we know what the genes are, then we can look for them in ourselves and turn them on."

DARPA-funded researchers are searching for such magical genes in mice and fruit flies.

Another approach is to improve upon an old ploy — using pharmaceutical stimulants. For decades the military has depended on caffeine and other, less common drugs to stay awake.

During World War II, U.S., British, German, and Japanese soldiers were issued amphetamines to counteract fatigue and heighten endurance. The Air Force's Surgeon General's Office has recently acknowledged the military still occasionally prescribes amphetamines to counter the effects of fatigue.

A more recently developed stimulant, modafinil (sold under the name Provigil), was approved by the Federal Drug Administration in 1999 and has been shown to keep people awake and alert for two days straight. More than 250,000 people now use the drug, although it was created mostly for people suffering from narcolepsy, a condition that triggers overwhelming impulses to sleep.

The military has tested modafinil for its usefulness in operations, but Carney says the program is seeking a better drug.

"Most drugs are developed for clinical diseases," he says. "This is not a clinical disease, this is a need. We want to select which effects we want a drug to employ."

Zapping the Brain

Rather than using drugs or gene therapy to keep awake, Yaakov Stern and Sarah Lisanby at Columbia University believe that finding the best treatment could just be a matter of tapping the human brain's unused potential.

"We're finding that some people do better than others on little sleep. I know people who can stay up all night and show almost no ill effects," says Stern, a professor of clinical neuropsychology at Columbia Health Sciences. "We're zeroing in on those who do better."

Stern and Lisanby are using two cutting-edge technologies to probe the brain with DARPA funding. Stern is using functional magnetic resonance imaging to observe people's brains as they perform memory tasks before and after missing sleep. Once key areas are identified, Lisanby plans to use transcranial magnetic stimulation (TMS) to trigger neurons to fire in these regions.

TMS is a brief, powerful magnetic field that sends electrical pulses to the brain. Other research has shown it can be effective in treating severe depression by stimulating neurons in areas of the brain that become less active during depression.

Lisanby, who is an associate professor of clinical psychiatry, says the hope is by triggering areas identified in people who function well with little sleep, scientists can help more vulnerable people become immune to the effects of sleep deprivation.

Eventually Lisanby plans to treat 75 sleep-deprived soldiers with TMS and then see how well they perform in memory tests and military tasks.

DARPA has always been about funding grand projects with bold goals. It was this agency, for example, that funded major development in Stealth technology and the Internet. But sleep and just how it rejuvenates the brain remains mysterious, and even DARPA scientists admit they don't expect to ever completely erase the body's need for it.

"We obviously need it," says Stern. "The idea of ridding people of the need for sleep is attractive, but it's probably too radical. The most we can hope for is to help people function as well as they can when they're sleep deprived."

As she plowed her way through finals week, Gatsinos said the idea of a safe method to skimp on sleep even for a few days — and not feel it — is definitely appealing.

"Lack of sleep becomes lifestyle around here," she says. "And I'm pre-med, so I know it will only get worse."