Discovery could yield treatment for cocaine addicts

March 15, 2013

Scientists have discovered a molecular process in the brain triggered by cocaine use that could provide a target for treatments to prevent or reverse addiction to the drug.

Reporting in the Journal of Neuroscience, Michigan State University neuroscientist A.J. Robison and colleagues say cocaine alters the , the brain's that responds to stimuli such as food, sex and drugs.

"Understanding what happens molecularly to this brain region during long-term exposure to drugs might give us insight into how addiction occurs," said Robison, assistant professor in the Department of Physiology and the Neuroscience Program.

The researchers found that cocaine causes cells in the nucleus accumbens to boost production of two proteins, one associated with addiction and the other related to learning. The proteins have a reciprocal relationship—they increase each other's production and stability in the cells—so the result is a that Robison calls a feed-forward loop.

Robison and colleagues demonstrated that loop's essential role in cocaine responses by manipulating the process in rodents. They found that raising production of the protein linked to addiction made animals behave as if they were exposed to cocaine even when they weren't. They also were able to break the loop, disrupting rodents' response to cocaine by preventing the function of the learning protein.

"At every level that we study, interrupting this loop disrupts the process that seems to occur with long-term exposure to drugs," said Robison, who conducted the study as a postdoctoral fellow at Mount Sinai School of Medicine in New York City before joining the faculty at MSU.

Robison said the study was particularly compelling because it found signs of the same feed-forward loop in the brains of people who died while addicted to cocaine.

"The increased production of these proteins that we found in the animals exposed to drugs was exactly paralleled in a population of human cocaine addicts," he said. "That makes us believe that the further experiments and manipulations we did in the animals are directly relevant to humans."

Robison said the growing understanding of addiction at the molecular level could help pave the way for new treatments for addicts.

"This sort of molecular pathway could be interrupted using genetic medicine, which is what we did with the mice," he said. "Many researchers think that is the future of medicine."

Explore further: Cocaine decreases activity of a protein necessary for normal functioning of the brain's reward system

Related Stories

Cocaine decreases activity of a protein necessary for normal functioning of the brain's reward system

April 22, 2012
New research from Mount Sinai Medical Center in New York reveals that repeated exposure to cocaine decreases the activity of a protein necessary for normal functioning of the brain's reward system, thus enhancing the reward ...

How the brain puts the brakes on the negative impact of cocaine

January 11, 2012
Research published by Cell Press in the January 12 issue of the journal Neuron provides fascinating insight into a newly discovered brain mechanism that limits the rewarding impact of cocaine. The study describes protective ...

Chronic cocaine use triggers changes in brain's neuron structure

May 9, 2012
Chronic exposure to cocaine reduces the expression of a protein known to regulate brain plasticity, according to new, in vivo research on the molecular basis of cocaine addiction. That reduction drives structural changes ...

Morphine and cocaine affect reward sensation differently

October 5, 2012
(Medical Xpress)—A new study by scientists in the US has found that the opiate morphine and the stimulant cocaine act on the reward centers in the brain in different ways, contradicting previous theories that these types ...

Recommended for you

'Residual echo' of ancient humans in scans may hold clues to mental disorders

July 26, 2017
Researchers at the National Institute of Mental Health (NIMH) have produced the first direct evidence that parts of our brains implicated in mental disorders may be shaped by a "residual echo" from our ancient past. The more ...

Laser used to reawaken lost memories in mice with Alzheimer's disease

July 26, 2017
(Medical Xpress)—A team of researchers at Columbia University has found that applying a laser to the part of a mouse brain used for memory storage caused the mice to recall memories lost due to a mouse version of Alzheimer's ...

Cellular roots of anxiety identified

July 26, 2017
From students stressing over exams to workers facing possible layoffs, worrying about the future is a normal and universal experience. But when people's anticipation of bad things to come starts interfering with daily life, ...

Cognitive cross-training enhances learning, study finds

July 25, 2017
Just as athletes cross-train to improve physical skills, those wanting to enhance cognitive skills can benefit from multiple ways of exercising the brain, according to a comprehensive new study from University of Illinois ...

Brain disease seen in most football players in large report

July 25, 2017
Research on 202 former football players found evidence of a brain disease linked to repeated head blows in nearly all of them, from athletes in the National Football League, college and even high school.

Lutein may counter cognitive aging, study finds

July 25, 2017
Spinach and kale are favorites of those looking to stay physically fit, but they also could keep consumers cognitively fit, according to a new study from University of Illinois researchers.

0 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.