Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Increasing dopamine in brain's frontal cortex decreases impulsive tendency, UCSF-Gallo study finds

26.07.2012
Raising levels of the neurotransmitter dopamine in the frontal cortex of the brain significantly decreased impulsivity in healthy adults, in a study conducted by researchers at the Ernest Gallo Clinic and Research Center at the University of California, San Francisco.

"Impulsivity is a risk factor for addiction to many substances, and it has been suggested that people with lower dopamine levels in the frontal cortex tend to be more impulsive," said lead author Andrew Kayser, PhD, an investigator at Gallo and an assistant professor of neurology at UCSF. "We wanted to see if we could decrease impulsivity by raising dopamine, and it seems as if we can."

The study was published on July 4 in the Journal of Neuroscience.

In a double-blinded, placebo-controlled study, 23 adult research participants were given either tolcapone, a medication approved by the Food and Drug Administration (FDA) that inhibits a dopamine-degrading enzyme, or a placebo. The researchers then gave the participants a task that measured impulsivity, asking them to make a hypothetical choice between receiving a smaller amount of money immediately ("smaller sooner") or a larger amount at a later time ("larger later"). Each participant was tested twice, once with tolcapone and once with placebo.

Participants – especially those who were more impulsive at baseline – were more likely to choose the less impulsive "larger later" option after taking tolcapone than they were after taking the placebo.

Magnetic resonance imaging conducted while the participants were taking the test confirmed that regions of the frontal cortex associated with decision-making were more active in the presence of tolcapone than in the presence of placebo.

"To our knowledge, this is the first study to use tolcapone to look for an effect on impulsivity," said Kayser.

The study was not designed to investigate the reasons that reduced dopamine is linked with impulsivity. However, explained Kayser, scientists believe that impulsivity is associated with an imbalance in dopamine between the frontal cortex, which governs executive functions such as cognitive control and self-regulation, and the striatum, which is thought to be involved in the planning and modification of more habitual behaviors.

"Most, if not all, drugs of abuse, such as cocaine and amphetamine, directly or indirectly involve the dopamine system," said Kayser. "They tend to increase dopamine in the striatum, which in turn may reward impulsive behavior. In a very simplistic fashion, the striatum is saying 'go,' and the frontal cortex is saying 'stop.' If you take cocaine, you're increasing the 'go' signal, and the 'stop' signal is not adequate to counteract it."

Kayser and his research team plan a follow-up study of the effects of tolcapone on drinking behavior. "Once we determine whether drinkers can safely tolerate this medication, we will see if it has any effect on how much they drink while they're taking it," said Kayser.

Tolcapone is approved as a medication for Parkinson's disease, in which a chronic deficit of dopamine inhibits movement.

Co-authors of the paper are Daicia C. Allen, BS, Ana Navarro-Cebrian, PhD, Jennifer M. Mitchell, PhD and senior author Howard L. Fields, MD, PhD, of the Gallo Center and UCSF.

The study was supported by funds from the Wheeler Center for the Neurobiology of Addiction, the U.S. Army Telemedicine and Advanced Technology Research Center, the Alcoholic Beverage Medical Research Foundation/The Foundation for Alcohol Research and the State of California.

The UCSF-affiliated Ernest Gallo Clinic and Research Center is one of the world's preeminent academic centers for the study of the biological basis of alcohol and substance use disorders. Gallo Center discoveries of potential molecular targets for the development of therapeutic medications are extended through preclinical and proof-of-concept clinical studies.

UCSF is a leading university dedicated to promoting health worldwide through advanced biomedical research, graduate-level education in the life sciences and health professions, and excellence in patient care.

Jennifer O’Brien | EurekAlert!
Further information:
http://www.ucsf.edu

More articles from Studies and Analyses:

nachricht First form of therapy for childhood dementia CLN2 developed
25.04.2018 | Universitätsklinikum Hamburg-Eppendorf

nachricht Do microplastics harbour additional risks by colonization with harmful bacteria?
05.04.2018 | Leibniz-Institut für Ostseeforschung Warnemünde

All articles from Studies and Analyses >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: BAM@Hannover Messe: innovative 3D printing method for space flight

At the Hannover Messe 2018, the Bundesanstalt für Materialforschung und-prüfung (BAM) will show how, in the future, astronauts could produce their own tools or spare parts in zero gravity using 3D printing. This will reduce, weight and transport costs for space missions. Visitors can experience the innovative additive manufacturing process live at the fair.

Powder-based additive manufacturing in zero gravity is the name of the project in which a component is produced by applying metallic powder layers and then...

Im Focus: Molecules Brilliantly Illuminated

Physicists at the Laboratory for Attosecond Physics, which is jointly run by Ludwig-Maximilians-Universität and the Max Planck Institute of Quantum Optics, have developed a high-power laser system that generates ultrashort pulses of light covering a large share of the mid-infrared spectrum. The researchers envisage a wide range of applications for the technology – in the early diagnosis of cancer, for instance.

Molecules are the building blocks of life. Like all other organisms, we are made of them. They control our biorhythm, and they can also reflect our state of...

Im Focus: Spider silk key to new bone-fixing composite

University of Connecticut researchers have created a biodegradable composite made of silk fibers that can be used to repair broken load-bearing bones without the complications sometimes presented by other materials.

Repairing major load-bearing bones such as those in the leg can be a long and uncomfortable process.

Im Focus: Writing and deleting magnets with lasers

Study published in the journal ACS Applied Materials & Interfaces is the outcome of an international effort that included teams from Dresden and Berlin in Germany, and the US.

Scientists at the Helmholtz-Zentrum Dresden-Rossendorf (HZDR) together with colleagues from the Helmholtz-Zentrum Berlin (HZB) and the University of Virginia...

Im Focus: Gamma-ray flashes from plasma filaments

Novel highly efficient and brilliant gamma-ray source: Based on model calculations, physicists of the Max PIanck Institute for Nuclear Physics in Heidelberg propose a novel method for an efficient high-brilliance gamma-ray source. A giant collimated gamma-ray pulse is generated from the interaction of a dense ultra-relativistic electron beam with a thin solid conductor. Energetic gamma-rays are copiously produced as the electron beam splits into filaments while propagating across the conductor. The resulting gamma-ray energy and flux enable novel experiments in nuclear and fundamental physics.

The typical wavelength of light interacting with an object of the microcosm scales with the size of this object. For atoms, this ranges from visible light to...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Invitation to the upcoming "Current Topics in Bioinformatics: Big Data in Genomics and Medicine"

13.04.2018 | Event News

Unique scope of UV LED technologies and applications presented in Berlin: ICULTA-2018

12.04.2018 | Event News

IWOLIA: A conference bringing together German Industrie 4.0 and French Industrie du Futur

09.04.2018 | Event News

 
Latest News

Getting electrons to move in a semiconductor

25.04.2018 | Physics and Astronomy

Reconstructing what makes us tick

25.04.2018 | Physics and Astronomy

Cheap 3-D printer can produce self-folding materials

25.04.2018 | Information Technology

VideoLinks
Science & Research
Overview of more VideoLinks >>>