Looking Into Brain to See Where It Hurts : Health: Researchers are using imaging techniques to pinpoint the part of the brain that controls pain. Then they would be able to design specific treatments.

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Folks who participate in Dr. Anthony Jones' research are asking for pain.

Volunteers stick their heads inside a brain-imaging machine while Jones pokes a hot electrode on the backs of their hands. The probe starts lukewarm, but Jones increases the heat until it grows hot and hurts.

Jones, a rheumatologist, is exploring how the brain controls pain.

Ultimately, he hopes his research will lead to more effective medicine for his arthritis patients and others who suffer from chronic aches and pains.

Currently, the treatment for people in constant discomfort is hit or miss--sometimes drugs, sometimes physical therapy.

In fact, many patients turn to traditional healers, experimenting with herbal remedies or acupuncture.

Jones is one of a growing number of researchers worldwide trying to unravel the mysteries of pain.

They have a hunch that chronic bombardment of pain centers, caused by arthritis or other diseases, eventually damages pathways that transmit signals in the brain.

The disrupted circuitry distorts messages so that even a minor tap or twist ignites excruciating pain.

If scientists could pinpoint the faulty circuits, they could design treatments to fix them.

Jones demonstrated that the crucial area for transmitting the sensation of pain is in the front of the brain, not the side as doctors had long assumed.

"Because people think the main areas of pain are in the lateral cortex (the side of the brain), that's where the big investment has been," Jones said.

"We're not saying it's not involved, but the frontal areas are key in terms of emotional response to pain."

Jones presented the results of his research at the British Society for Rheumatology Meeting in Cambridge, England.

Six healthy men participated in Jones's PET scan study. PET scans, short for positron emission tomography, trace blood flow.

The volunteers slid into the scanning machine. Then Jones gradually increased the heat of the electrode.

PET scans produce colorful pictures of the inner workings of the brain.

The more blood flow, the brighter the color in that brain region.

Investigators think changes in blood flow reflect the amount of activity in nerve cells.

Jones found that pain caused a dramatic change in the intensity of color in the front of the brain, specifically in a region called the cingulate cortex.

At the same time, researchers working independently in Canada got the same results with PET scans.

"For the first time, his team and ours showed that cortical centers are involved in pain processing. This involvement of the cingulate cortex was actually a surprise," said Dr. Ernst Meyer, an investigator at the Montreal Neurological Institute.

Dr. Brent Vogt, a professor of physiology and pharmacology at Wake Forest University in Winston-Salem, N.C., said Jones' work lends credence to his own theories about the cingulate cortex.

Vogt is a co-editor of the recently published book "Neurobiology of Cingulate Cortex and Limbic Thalamus" and is doing brain scan research at the Medical Research Council Cyclotron Unit at Hammersmith Hospital in London.

For years, some neurosurgeons have treated patients suffering from unmanageable, severe pain by removing a piece of the cingulate cortex.

Most doctors had assumed that the surgery worked because surgeons cut connections leading to a pain center, located elsewhere in the brain.

Vogt said the PET studies prove that the cingulate cortex is the pain center.

Now the goal is to pinpoint the precise circuits within the cingulate region.

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