Sleeping With More Than One Eye Open

[eric myers 2]

July 5, 2005
Sleeping With More Than One Eye Open
By HENRY FOUNTAIN
Sleep is vital to the development of brain and body. That truism comes from basic observations about humans and other mammals, that sleep is maximized at birth and declines gradually until adulthood.

But a new finding threatens to throw that common wisdom out the window. For researchers have discovered that some whales and dolphins don't sleep after birth. Both newborns and their mothers stay continuously active for about a month and then gradually build up their sleep to normal adult levels after four or five months.

"What's going on is very different than any animal ever encountered," said Dr. Jerome Siegel, a professor of psychiatry at the University of California, Los Angeles and an author of a paper describing the finding in Nature. Dr. Siegel and his colleagues studied newborn killer whales and bottlenose dolphins, recording their activities in pools at Sea World in San Diego and in an aquarium in Russia.

Dolphins had already been known to exhibit unusual resting behavior: they sleep with one eye open. At any time only one brain hemisphere shows activity that is characteristic of a certain kind of sleep.

Dolphins have also never been shown to exhibit rapid-eye-movement sleep, Dr. Siegel said, but scientists had suspected that this might be because the dolphins studied had not been young enough.

So when Dr. Siegel heard about another cetacean, a killer whale, being born at Sea World, he sent a student, Oleg Lyamin, to study it. "He came back and was astounded to report that not only wasn't there REM sleep, there didn't appear to be any sleep at all," Dr. Siegel said.

Rather than floating at the surface or lying at the bottom of the pool, which are normal sleep activities, the dolphins and whales studied all swam continuously and navigated around other animals, a sure sign of consciousness. "Unquestionably the amount of sleep is minimal at birth," Dr. Siegel said.

Why don't these animals need REM sleep? "It may be that REM sleep has a function for stimulating the brain, and non-REM sleep is more of a rest state," he said. "And because dolphins never have a brain in a rest state, there's no need for it."

"But how they do without sleep in general," he added, "I don't have a clue."

Wiring the Molecules

Transistors, diodes and other elements that make up a silicon chip may be small, but for some scientists they aren't small enough. These researchers are trying to make components from single molecules, which would be much smaller and would enable corresponding reductions in the size of electronic devices.

But this emerging field, molecular electronics, faces some significant hurdles, not the least of them the problem of how to connect a single-molecule component to a source of electricity. Since molecules are very tiny - only billionths of a meter long - figuring out how to wire them up has been daunting.

If you were wiring a conventional circuit board, say, you'd take a resistor or other component and solder wires to either end. But the basic approach in molecular electronics is different: you make a wire first, create a tiny gap in it of a specific width and drop the single-molecule component snugly into it so it connects at both sides.

Dr. Lidong Qin and other researchers at Northwestern have come up with a process that is simpler and more effective than other techniques developed to date. Called on-wire lithography and described in the journal Science, it uses electrochemical deposition to create tiny metal wires, using a template that is then dissolved away.

Each wire is mostly of one metal - gold, commonly - with small sections of silver or another metal. By controlling the deposition process, the silver sections can be made very short, matching the dimensions of particular molecular components.

The wire is then attached to a sheath so it won't fall apart and put in a solution that etches away only the silver sections. What's left is a gold wire with precise gaps along its length that the molecular components can be dropped into. So far, the researchers have made gaps as small as five nanometers - not quite small enough. But with more work, the gaps should narrow.

Post-Hurricane Fish Calls

Hurricane Charley devastated parts of Florida and other Southern states when it hit last August. Ten people were killed, millions lost power and property damage was estimated at $14 billion.

But the hurricane, the most powerful one to hit the mainland since 1992, had an effect on fish, too. Two researchers from the University of South Florida, Dr. James V. Locascio and Dr. David A. Mann, found that immediately after the storm, fish in the path of the hurricane produced courtship calls that were louder and lasted longer than those in the preceding days.

Serendipity played a role in the finding, which was reported in the journal Biology Letters. The scientists had been studying nightly courtship calls of sand seatrout and other species in Charlotte Harbor, Fla., for two years using an underwater recording system. The goal of the research was to try to determine where and when spawning was occurring.

On the afternoon of Aug. 13, Charley passed over the harbor with winds exceeding 140 miles an hour. The recorder, near the harbor floor at a depth of about 12 feet, picked up loud low-frequency rumbles.

After the fast-moving storm passed, the recorded chorus of higher-frequency fish calls, mostly from sand seatrout, was louder than it had been in the previous nine days. The louder calls continued for the next three days, and began up to two and a half hours earlier than normal. The researchers are not sure why the changes occurred but suggest that the storm may have affected the distribution of fish in the harbor.

Good Whale News

This has been a good year for North Atlantic right whales, one of the most endangered whale species. Last week, scientists with the National Marine Fisheries Service confirmed the 28th sighting of a mother-calf pair. The animals were videotaped off South Carolina and had earlier been spotted off Florida.

The number of sightings makes this year one of the best on record. There are only an estimated 300 North Atlantic right whales remaining, so the more calves spotted, the more hope that the whales' decline might be stopped or reversed.