Nora Volkow: Two paths to the future pg. 6
The university hospital had no patients with schizophrenia to study, Volkow recalls, but there were plenty of cocaine addicts. So, with the help of addiction specialist Kenneth Krajewski, M.D., and physicists Nizar Mullani and Stephen Adler, Volkow conducted the first PET studies of the brains of cocaine addicts.
At first, she says, no one believed the images of deranged blood flow, suggestive of stroke. It would be 1988—three years later—before their findings were published by the British Journal of Psychiatry.
By then, Volkow and Adler had married and had accepted positions at Brookhaven.
Volkow, who also joined the faculty in psychiatry at the State University of New York at Stony Brook, says she was tempted back by Wolf’s offer to label cocaine for her. “That was extraordinary,” she says, “because it actually opened up the first study to be able to look at the dynamics of these drugs in the brain.”
In 1993, the Brookhaven group reported that cocaine abusers had lower levels of the dopamine D2 receptor compared to normal controls. Reductions in receptor levels were associated with decreased metabolism, as measured by glucose consumption, particularly in the orbitofrontal cortex and cingulate gyrus.
The cingulate gyrus, a ridge of tissue deep in the brain, is part of the limbic system, associated with mood and emotions. What was surprising was the connection to the orbitofrontal cortex, located just above the eyes, the same area that functions abnormally in patients with obsessive-compulsive disorder and that is believed to underlie their compulsive behaviors.
“We always thought of drug addiction as a disease of the primitive parts of our brain, the limbic parts… the pleasure centers,” Volkow said in a 2002 lecture. “And here, the frontal cortex, which epitomizes the higher levels of our ‘reasoning’ human brain, appears to be involved.”