COCK-A-DOODLE QUAIL

By Frederic Golden

The small bundles of fluff and feathers looked like any other freshly hatched chickens. But when these Plymouth Rock hatchlings began chirping, it was clear that they were rare birds indeed. Instead of launching into the usual chicken songs, they crowed and bobbed like baby quail. Some harkened to danger calls from adult quail but didn't so much as cock-a-doodle-doo when called by mama hens.

A barnyard foul-up? Not at all. The chicks' identity crisis was a scientific coup, demonstrating convincingly how instinctive ("hardwired") behavior can be shuttled from one species to another. The feat, moreover, was accomplished not by crossbreeding or genetic engineering but through the artful replacement of selected brain cells in a chicken embryo with those from the embryo of a Japanese quail, a fowl of a completely different sort.

Neurobiologist Evan Balaban of the Neurosciences Institute in San Diego undertook the experimental tour de force to explore one of developmental biology's nagging questions: Where in the brain are the cells controlling specific behaviors? Using delicate surgical techniques pioneered by Nicole le Douarin in Paris, with whom he worked for a year, Balaban cut tiny windows in the shells of fertilized chicken and quail eggs that had incubated for a couple of days. Guided by special stains developed by the French researcher, he probed the embryos' minuscule, 1-mm- to 2-mm-long neural tubes (out of which the brains develop), removing cells from the chickens and replacing them with corresponding cells from the quail. Closing up the windows, he returned the chicken eggs to the incubator, allowing them to hatch at a normal 21 days, whereupon they soon began crowing.

But not like any baby chicks. Rather than sticking their heads rapidly upward and forward, then holding still while they squealed, they wobbled their heads up and down like quail. Or they postured like chickens but engaged in the distinctive three-note quail song. After much trial and error, Balaban--an amateur baroque musician who sometimes serenaded his chicks with his lute to stimulate their singing--traced the movements and sounds to two very different areas in the brain. "That's new. That's interesting," says Caltech neurobiologist Masakazu Konishi. "It means posture and sound that usually occur together in crowing are controlled by different neuromechanisms."

Coming as it did amid the recent cloning furor, the report of Balaban's experiments published last week in the Proceedings of the National Academy of Sciences created yet more public concern about biological tinkering, not to mention a fresh wave of stale chicken jokes. (Why did the mad scientist kick the chickens out of his lab? Because they were using fowl language.) Raising the specter of brain transplants in humans, radio talk-show host Rush Limbaugh blustered, "This is more dangerous than cloning!"

But Balaban brushed off the concerns. Human brain transplants would not work, he explains, because the early mammalian embryo is far too fragile for any sort of cell manipulation. Besides, much of human behavior is learned, not hardwired. So what practical results might come from his work? Balaban sees it as a first step toward a very different goal: learning enough about the structure and function of the brain so that when human brain cells are damaged, say by stroke, other cells might be recruited to take over.

--By Frederic Golden