Can Changing Dopamine Levels Help to Treat Drug Addiction?

By Paul Gaita 03/14/17

A new study examined the role dopamine played in the decision-making process.

Hand holding image of a brain.

The neurotransmitter called dopamine is one of the brain's most crucial components—controlling not only reward and pleasure systems, but also regulating movement and emotional response to rewards.

Neurological diseases such as Parkinson's, as well as long-term drug abuse, can result in low or impaired levels of dopamine production and hamper the ability to halt repetitive or damaging actions. But new research is delving into the possibility that altering dopamine levels may assist individuals in having greater control over their actions.

In a new study published online in the journal Neuron, scientists from the Salk Institute for Biological Studies sought to determine if targeted dopamine therapy could have a positive impact on decision-making. This was determined through an experiment involving two mice as test subjects that were placed in a chamber with levers on its right and left side, and a treat dispenser at the center of the chamber. 

As the mice performed the experiment, the scientists measured dopamine levels in their brains through embedded electrodes that indicated rapid changes in brain chemistry. The results showed that elevated or lowered dopamine levels were closely associated with the animals' decision-making, and even allowed the scientists to accurately predict which lever would be pressed, based solely on dopamine levels.

Further confirming their hypothesis was a second test in which mice received a treat by pressing either lever. Dopamine levels in these subjects' brains increased at the start of the trial, but never rose above baseline levels for the remainder of the test.

"We are very excited by these findings, because they indicate that dopamine could also be involved in ongoing [decision-making], beyond its well-known role in learning," said study author Christopher Howard.

To confirm that dopamine was a key factor in choice and not just linked to the process, the research team used a combination of genetic engineering and molecular technology to alter the subjects' brain dopamine levels in real time. What they found was that they were able to make the mice switch their choices from one level to another by either increasing or decreasing the amount of the neurotransmitter.

The study authors say the experiment suggests that altering dopamine levels could make a difference in how actions are selected by individuals. "This is an important step in understanding how to accomplish that," said co-author Xin Jin. "I think that if we could restore the appropriate dopamine dynamics in [cases of] Parkinson's disease, obsessive-compulsive disorder and drug addiction, people might have better control of their behavior."

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Paul Gaita lives in Los Angeles. He has contributed to the Los Angeles Times, Variety, LA Weekly, and The Los Angeles Beat, among many other publications and websites.