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

Related Stories

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

Umbilical cells help eye's neurons connect

November 24, 2015

Cells isolated from human umbilical cord tissue have been shown to produce molecules that help retinal neurons from the eyes of rats grow, connect and survive, according to Duke University researchers working with Janssen ...

Brain connections predict how well you can pay attention

November 24, 2015

During a 1959 television appearance, Jack Kerouac was asked how long it took him to write his novel On The Road. His response – three weeks – amazed the interviewer and ignited an enduring myth that the book was composed ...

No cable spaghetti in the brain

November 24, 2015

Our brain is a mysterious machine. Billions of nerve cells are connected such that they store information as efficiently as books are stored in a well-organized library. To this date, many details remain unclear, for instance ...

Neurons encoding hand shapes identified in human brain

November 23, 2015

Neural prosthetic devices, which include small electrode arrays implanted in the brain, can allow paralyzed patients to control the movement of a robotic limb, whether that limb is attached to the individual or not. In May ...

Wireless sensor enables study of traumatic brain injury

November 23, 2015

A new system that uses a wireless implant has been shown to record for the first time how brain tissue deforms when subjected to the kind of shock that causes blast-induced trauma commonly seen in combat veterans.

Neuroscientists reveal how the brain can enhance connections

November 18, 2015

When the brain forms memories or learns a new task, it encodes the new information by tuning connections between neurons. MIT neuroscientists have discovered a novel mechanism that contributes to the strengthening of these ...


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.