Scientists Identify Drug-Craving Brain Region
Scientists from Chili have discovered that blocking a region of the brain called the insular cortex causes rats that are addicted to amphetamines to stop craving the drug. This understanding could lead to the development of new therapies to help treat drug addiction.
The insular cortex is located deep in the brain, and is part of the sensory system that monitors how an individual perceives their own physiological states and needs. When the body craves a drug, individuals can get irritable and anxious.
These types of physiological states appear to be controlled by the insular cortex, according to the study. When the researchers injected a drug that inactivated the insular cortex, drug-addicted rats that had previously shown symptoms of craving amphetamines suddenly stopped craving the drug. When the insular cortex was re-activated, the rats again showed signs of craving.
In effect, this means that the insular cortex informs the rest of the brain about craving. In the absence of the insular cortex, the rats did not realize that their body "needed" the drug.
"Since this region serves the perception of bodily needs and emotions, it may be a key structure in decision making by informing the executive prefrontal cortex of our needs as in the case of drug abuse," said researcher Fernando Torrealba of the Pontifical Catholic University of Chile.
In a second experiment, the scientists found that rats with inactive insular cortexes did not appear to suffer stomach aches induced by taking the drug lithium. This finding suggests that the insular cortex may play a far-reaching role in processing information about physiological states that guide behavior and self-awareness.
The researchers hope to find a method to prevent craving for longer time periods, along with alleviating some of the symptoms associated with drug addiction. The study is published in the journal Science.