Schizophrenia may spring from a smorgasbord

A study has found that rare and previously undetectable genetic variations may significantly increase the risk that a person will develop schizophrenia. Experts said the study, while not identifying the cause of the disorder, provided a striking demonstration of how new gene-scanning technology can open a frontier in the quest to understand the biology of mental disorders.

Until now, researchers had focused on finding common and known genetic variations that, when acting in some combination, might increase the risk for schizophrenia. They have had little success. The new analysis, being published today in the journal Science, detected extremely rare and unknown mutations that turned up three to four times as often in people with schizophrenia as in those without it. The findings point scientists to previously unappreciated developmental problems that may help them develop more effective treatments, experts said.

Researchers have tried for generations to understand the biological underpinnings of schizophrenia, which affects 1 percent of the population, causing scrambled thinking and delusions. They have analyzed how drugs prescribed for the disorder affect brain cells. They have run large genetic studies, looking in vain for some shared pattern.

Genetics found to be even more complicated

The new study suggests that, if anything, the genetics of the disorder are even more complex than many had presumed. But if replicated, experts said, the study's results will significantly alter the course of psychiatric research.

Dr. Samuel Barondes, a professor of psychiatry at the University of California, San Francisco, said, "This is a field that has been grasping for straws, and this study is one big straw."

In the study, a collaboration that included the National Institute of Mental Health, the University of Washington, Seattle, and Cold Spring Harbor Laboratory, investigators analyzed blood samples from 150 people with a diagnosis of schizophrenia and 268 without a psychiatric disorder. Using high-resolution techniques that quickly scan the entire human DNA map, researchers looked for rare variations that disrupted the function of genes. Some of these mutations are inherited; others occur spontaneously during or near conception.

'A new way to search for genetic links'

They found 53 such mutations overall and reported that the mutations that disrupted genes were three times as likely to turn up in people with schizophrenia as in those without it. A similar analysis, in 83 people who developed a rare form of schizophrenia that strikes in childhood, found they were four times as likely as healthy people to have a rare gene-altering mutation. The mutations varied from person to person but were concentrated in genes known to influence brain development.

"The take-home message is that there's a new way to search for genetic links, and this new method goes straight to the underlying biology," said senior author Jonathan Sebat, an assistant professor of genetics at Cold Spring Harbor Laboratory.

ODORS CAN HELP THE BRAIN SENSE YOU'RE IN DANGER

Know how a whiff of certain odors can take you back in time, either to a great memory or bad one? It turns out emotion plays an even bigger role with the nose, and your sense of smell can sharpen when something bad happens.

Northwestern University researchers proved the surprising connection by giving volunteers electric shocks while they sniffed novel odors.

The discovery, reported in today's edition of the journal Science, helps explain how our senses can steer us clear of danger. More intriguing, it could shed light on disorders such as post-traumatic stress syndrome (PTSD).

Scientists long have known of a strong link between the sense of smell and emotion. A certain perfume or scent of baking pie, for instance, can raise memories of a long-dead loved one. Conversely, a whiff of diesel fuel might trigger a flashback for a soldier with PTSD.

In the study, MRI scans showed there were changes in how the brain's main olfactory region stored the odor information, essentially better imprinting the shock-linked scent so it could be distinguished more quickly from a similar odor.

INSIGHTS INTO THE GIANT SQUID'S FLEXIBLE BEAK

The razor-sharp beaks that giant squids use to attack whales might one day lead to improved artificial limbs for people. That deadly beak has long puzzled scientists; they wonder how a creature without any bones can operate it without hurting itself.

Now, researchers at the University of California, Santa Barbara, report in today's journal Science that they have an explanation.

The beak, made of hard chitin and other materials, changes density gradually from the hard tip to a softer, more flexible base where it attaches to the muscle around the squid's mouth, the researchers found. That means the tough beak can chomp away at fish, but the hard material doesn't press or rub directly against the squid's softer tissues.

Researcher Ali Miserez, co-author of the paper, suggested the research could point the way to new types of medical materials. "We could maybe imagine creating a full prosthesis that mimics the chemistry of the beak, so that it matches the elasticity of cartilage on one side and, on the other side, you could create a material which is very stiff and abrasion resistant."

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