Researchers at the University of Texas Southwestern Medical Center have identified a chemical system in the brain that reacts differently in cocaine addicts. This could mean new treatment options for those people addicted to cocaine.
"We found that the amount of blood flow in areas of the brain known to be involved in the rewarding effects of cocaine and craving was different in cocaine addicts, compared with healthy subjects," said Dr. Bryon Adinoff, professor of psychiatry at UT Southwestern and the lead author of the study.
"Now we have a new target for pharmacologic intervention," said Adinoff.
The study looked at changes in the brain’s cholinergic system, which involves the neurotransmitter acetylcholine and its receptors, on brain cells to which the chemical attaches itself. A disruption of this sytem has been implicated in Alzheimer’s disease. In animal models of addiction, the neurotransmitter has been shown to affect how hard an animal will work to get a drug, but until now, the cholinergic system’s relation to addiction in humans had not been studied.
The researchers studied how changes in the cholinergic system affected the limbic region in the brain of cocaine-addicted study subjects. The limbic region of brain supports emotions, behavior, learning and long-term memory.
Most previous studies of addiction have focused on the function of dopamine. Dopamine is associated with the "pleasure system" of the brain and is released by naturally rewarding experiences like food, sex and drug use.
"Very few treatments affecting these other chemical systems have been effective at helping cure addiction," said Dr. Michael Devous, professor of radiology at UT Southwestern and an author of the study. "We have discovered abnormalities in the cholinergic system of cocaine addiction that may relate more to the addictive process than the reward process."
