Cocaine and the teen brain: Study offers insights into addiction

When first exposed to cocaine, the adolescent brain launches a strong defensive reaction designed to minimize the drug's effects, Yale and other scientists have found. Now two new studies by a Yale team identify key genes that regulate this response and show that interfering with this reaction dramatically increases a mouse's sensitivity to cocaine.

The findings may help explain why risk of drug abuse and addiction increase so dramatically when begins during .

The results were published in the Feb. 14 and Feb. 21 issues of the Journal of Neuroscience.

Researchers including those at Yale have shown that vulnerability to cocaine is much higher in adolescence, when the brain is shifting from an explosive and plastic growth phase to more settled and refined characteristic of adults. Past studies at Yale have shown that the neurons and their in adolescence change shape when first exposed to cocaine through molecular pathway regulated by the gene integrin beta1, which is crucial to the development of the nervous system of vertebrates.

"This suggests that these structural changes observed are probably protective of the neurocircuitry, an effort of the neuron to protect itself when first exposed to cocaine," said Anthony Koleske, professor of and biochemistry and of neurobiology and senior author of both papers.

In the latest study, Yale researchers report when they knocked out this pathway, mice needed approximately three times less cocaine to induce than mice with an intact pathway.

The research suggests that the relative strength of the integrin beta1 pathway among individuals may explain why some cocaine users end up addicted to the drug while others escape its worst effects, Koleske theorized.

"If you were to become totally desensitized to cocaine, there is no reason to seek the drug," he said.

Koleske and Jane R. Taylor, professor of psychiatry and psychology and an author of the Feb. 14 paper, are teaming up with other Yale researchers to look for other genes that may play a role in protecting the brain from effects of cocaine and other drugs of abuse.

Shannon Gourley, now of Emory University who worked with Koleske and Taylor, is lead author on the Feb. 14 paper detailing how the structural response to cocaine protects against cocaine sensitivity. Anastasia Oleveska and Michael S. Warren are other Yale authors on this paper. Warren and William D. Bradley of Yale are co-lead authors of the latest Neuroscience paper describing the role for integrin beta 1 in the control of adolescent synapse and dendrite refinement and stability. Yu-Chih Lin, Mark A. Simpson, Charles A. Greer are other Yale-affiliated authors.

Related Stories

Abnormal brain structure linked to chronic cocaine abuse

Jun 21, 2011

Researchers at the University of Cambridge have identified abnormal brain structures in the frontal lobe of cocaine users' brains which are linked to their compulsive cocaine-using behaviour. Their findings were published ...

Tuning cocaine addiction

Jul 19, 2010

small bits of genetic material that influence gene expression - reduces the urge for a cocaine fix in mice, according to a paper published online on July 19 in the Journal of Experimental Medicine.

Recommended for you

Link seen between seizures and migraines in the brain

12 hours ago

Seizures and migraines have always been considered separate physiological events in the brain, but now a team of engineers and neuroscientists looking at the brain from a physics viewpoint discovered a link ...

Neuroscience: Why scratching makes you itch more

18 hours ago

Turns out your mom was right: Scratching an itch only makes it worse. New research from scientists at Washington University School of Medicine in St. Louis indicates that scratching causes the brain to release ...

User comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.