Research Links Change in Brain with Addiction

February 1, 2007

A researcher at the University at Buffalo's Research Institute on Addictions (RIA) has found a change in the brain that occurs after drug use and that may contribute to drug addiction.

The finding, reported in the January 2007 issue of the journal Biological Psychiatry, demonstrates that repeated exposure to different types of drugs of abuse such as cocaine, nicotine, amphetamine, and alcohol lead to a persistent or long-term reduction in the electrical activity of dopamine neurons in the brain.

Dopamine neurons are the origin of the reward pathway responsible for the "feel good" experience that is such a strong component of drug use and abuse.

"A persistent reduction in dopamine neuron electrical activity after repeated exposure to different types of drugs appears to be the result of excessive excitation of dopamine neurons," according to Roh-Yu Shen, Ph.D., a neuroscientist and the lead investigator on the study. "This represents a new and potentially critical neural mechanism for addiction and provides a working model that suggests how the reward pathway function is altered and how these changes can be responsible for triggering intense craving and compulsive drug-seeking."

Initial exposure to drugs of abuse causes dopamine neurons to release dopamine in target areas of the brain that provide the reward effect of using drugs. Repeated abuse of drugs results in long-lasting changes in the function of the reward pathway that leads to craving for drugs and the compulsion for more drugs.

Shen is a senior research scientist at RIA and holds adjunct appointments in the Department of Pathology and Anatomical Sciences in the UB School of Medicine and Biomedical Sciences and Department of Psychology in the UB College of Arts and Sciences. Her colleagues on this study include Kar-Chan Choong, RIA research assistant, who performed the experiments, and Alexis C. Thompson, Ph.D., RIA research scientist and research associate professor in UB's Department of Psychology.

Shen said the persistent or long-lasting nature (3-6 weeks in animal models equivalent to approximately two years in humans) of this effect helps to explain why it is so difficult to abstain from

using cocaine, nicotine, amphetamine and alcohol. In addition, she added, it is a time-dependent effect that is not seen immediately after drug use, but rather manifests over a period of time following drug use and intensifies over time.

Shen and colleagues have concluded that the persistent reduction in dopamine activity parallels the long-lasting nature of addictive behaviors, including intensified craving and compulsive drug-seeking behavior. A next step is for treatment researchers to develop treatment protocols that build on this biological finding.

Source: University at Buffalo

Explore further: Caffeine-based compounds show promise against Parkinson's disease

Related Stories

What parts of the brain make our personalities so unique?

September 30, 2016

The brain is key to our existence, but there's a long way to go before neuroscience can truly capture its staggering capacity. For now though, our Brain Control series explores what we do know about the brain's command of ...

Why danger is exciting – but only to some people

September 6, 2016

It has been the most deadly summer for wingsuit flying to date. But what makes some people want to base jump off a cliff, binge drink to oblivion or hitchhike with strangers while others don't even enjoy a rollercoaster ride? ...

Researchers eye potential schizophrenia 'switch'

September 19, 2016

Researchers at Vanderbilt University Medical Center have discovered a key mechanism that explains how compounds they're developing can suppress schizophrenia-like symptoms in mice without side effects.

Recommended for you

How the finch changes its tune

August 3, 2015

Like top musicians, songbirds train from a young age to weed out errors and trim variability from their songs, ultimately becoming consistent and reliable performers. But as with human musicians, even the best are not machines. ...

Cow embryos reveal new type of chromosome chimera

May 27, 2016

I've often wondered what happens between the time an egg is fertilized and the time the ball of cells that it becomes nestles into the uterine lining. It's a period that we know very little about, a black box of developmental ...

Shaving time to test antidotes for nerve agents

February 29, 2016

Imagine you wanted to know how much energy it took to bike up a mountain, but couldn't finish the ride to the peak yourself. So, to get the total energy required, you and a team of friends strap energy meters to your bikes ...

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.