SPOT DEEP IN BRAIN LINKED TO ADDICTION

WASHINGTON -- Damage to a silver-dollar-sized spot deep in the brain
seems to wipe out the urge to smoke, a discovery that may shed
important light on addiction. The research was inspired by a stroke
survivor who claimed he simply forgot his two-pack-a-day addiction --
no cravings, no nicotine patches, not even a conscious desire to quit.

"The quitting is like a light switch that went off," said Antoine
Bechara of the University of Southern California, who scanned the
brains of 69 smokers and ex-smokers to pinpoint the region involved.

The finding, reported in today's edition of the journal Science,
points scientists toward new ways to develop antismoking aids by
targeting the little-known brain region called the insula. And it
sparked excitement among addiction specialists who expect the insula
to play a key role in other addictions.

"It's a fantastic paper; it's a fantastic finding," said Nora Volkow,
director of the National Institute on Drug Abuse and a longtime
investigator of the brain's addiction pathways.

The study "shows unequivocally is the insula is a key structure in the
brain for perceiving the urges to take the drug," urges that are "the
backbone of the addiction," Dr. Volkow said.

The insula seems to be where the brain turns physical reactions into
feelings -- like feeling anxious when your heart speeds up. When those
reactions are caused by a particular substance, the insula may act as
a sort of headquarters for cravings.

Some 44 million Americans smoke, and the government says more than
400,000 people a year die of smoking-related illnesses. Declines in
smoking have slowed in recent years, making it unlikely that the U.S.
will reach a public health goal of cutting the rate to 12% by 2010.

Nicotine is one of the most addictive substances known, and it is
common for smokers to relapse repeatedly when they try to quit. It
isn't unusual for a health scare to prompt an attempt at quitting.
"That's the quitting that's not as interesting," Dr. Bechara said. If
Dr. Bechara's findings are validated, they suggest that developing
drugs that target the insula might help smokers quit. There are
nicotine receptors in the insula, meaning it should be possible to
create a nicotine-specific drug, Dr. Bechara said -- albeit years from
now.

More immediately, Dr. Volkow of NIDA wants to try a different
experiment: Scientists can temporarily alter function of certain brain
regions with pulses of magnetic energy, called "transcranial magnetic
stimulation." She wants to see if it's possible to focus such magnetic
pulses on the insula, and thus verify its role.

Other neurologic functions are known to be involved with addiction,
too, such as the brain's "reward" or pleasure pathways. The insula
discovery doesn't contradict that work, but adds another layer to how
addiction grips the brain, Dr. Bechara said.