Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Study offers clues to brain's protective mechanisms against alcoholism

05.09.2006
A new study provides clues that differing brain chemistry may provide part of the answer to why some people with a strong family history of alcoholism develop alcohol dependency while others do not.

Why do some people with a strong family history of alcoholism develop alcohol dependency while others do not? A new study provides clues that differing brain chemistry may provide part of the answer. Researchers from four scientific institutions and federal agencies working at the U.S. Department of Energy's Brookhaven National Laboratory have found that elevated levels of D2 receptors for dopamine -- a chemical "messenger" in the brain's reward circuits -- may provide a protective effect for those most at risk for developing alcoholism. The study, part of an ongoing effort to understand the biochemical basis of alcohol abuse, also provides new evidence for a linkage between emotional attributes and brain function. The study appears in the September 2006 issue of the Archives of General Psychiatry.

"Higher levels of dopamine D2 receptors may provide protection against alcoholism by triggering the brain circuits involved in inhibiting behavioral responses to the presence of alcohol," said lead author Nora D. Volkow, Director of the National Institute on Drug Abuse (NIDA) and former Associate Laboratory Director for life sciences research at Brookhaven Lab. "This means that treatment strategies for alcoholism that increase dopamine D2 receptors could be beneficial for at-risk individuals."

Earlier Brookhaven Lab studies have demonstrated that increasing dopamine D2 receptors by genetic manipulation decreased alcohol consumption in rats that had been trained (http://www.bnl.gov/bnlweb/pubaf/pr/2001/bnlpr090501.htm) or that were genetically predisposed (http://www.bnl.gov/bnlweb/pubaf/pr/PR_display.asp?prID=04-47) to drink large quantities of alcohol. Another study found that such D2-receptor "gene therapy" reduced drinking in mice with normal to moderately low levels of D2 receptors (http://www.bnl.gov/bnlweb/pubaf/pr/PR_display.asp?prID=05-49). The current study adds to the evidence that D2 receptors modulate the motivation to drink alcohol and that increasing these receptors could play a role in the treatment of alcoholism. The D2 receptor is one of five dopamine receptor subtypes.

In this study, researchers compared the number of dopamine D2 receptors in two groups: 16 nonalcoholic individuals with no family history of alcoholism and 15 nonalcoholic individuals who had a positive family history of alcoholism -- an alcoholic biological father with early onset of alcoholism and at least two other first or second degree relatives (parent, child, sibling, grandparent, grandchild, cousin, aunt, uncle) with alcoholism. The latter group was at a very high risk of developing alcoholism. The researchers studied high-risk individuals rather than looking at people with drinking disorders because chronic alcohol abuse reduces the number of dopamine receptors, making comparisons difficult. Participants were scanned with positron emission tomography (PET) and were given two radioactive tracers to assess their dopamine D2 receptor levels and brain glucose -- a marker of brain function.

The scans demonstrated high levels of dopamine D2 receptors in the brains of participants with a family history of alcoholism, particularly in their frontal regions -- 10 percent higher, on average, than in the brains of those with no family history. These areas of the brain -- including the caudate and ventral striatum -- are involved in emotional reactions to stress and cognitive control of decisions about drinking.

"This suggests that dopamine D2 receptors in these brain regions protect high-risk individuals from becoming alcoholic," said principal investigator Gene-Jack Wang, who chairs Brookhaven Lab's Medical Department and is clinical head of the PET Imaging Group at the Lab's Center for Translational Neuroimaging. "This protective effect may combine with emotional and environmental factors to compensate for higher inherited vulnerability."

Each study participant was given a Multidimensional Personality Questionnaire, to measure for extroversion and introversion, also known as positive and negative emotionality. Positive emotionality is believed to decrease the likelihood of alcohol abuse. This test was given to determine whether the receptors' protective effect was associated with this or other personality characteristics.

"We found that individuals who had the highest level of dopamine D2 receptors were those who were extroverted and more motivated by positive rewards," said Volkow. "This held true for both individuals with and without a family history of alcoholism."

Dennis Tartaglia | EurekAlert!
Further information:
http://www.bnl.gov/world/

More articles from Studies and Analyses:

nachricht The personality factor: How to foster the sharing of research data
06.09.2017 | ZBW – Leibniz-Informationszentrum Wirtschaft

nachricht Europe’s Demographic Future. Where the Regions Are Heading after a Decade of Crises
10.08.2017 | Berlin-Institut für Bevölkerung und Entwicklung

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: Highly precise wiring in the Cerebral Cortex

Our brains house extremely complex neuronal circuits, whose detailed structures are still largely unknown. This is especially true for the so-called cerebral cortex of mammals, where among other things vision, thoughts or spatial orientation are being computed. Here the rules by which nerve cells are connected to each other are only partly understood. A team of scientists around Moritz Helmstaedter at the Frankfiurt Max Planck Institute for Brain Research and Helene Schmidt (Humboldt University in Berlin) have now discovered a surprisingly precise nerve cell connectivity pattern in the part of the cerebral cortex that is responsible for orienting the individual animal or human in space.

The researchers report online in Nature (Schmidt et al., 2017. Axonal synapse sorting in medial entorhinal cortex, DOI: 10.1038/nature24005) that synapses in...

Im Focus: Tiny lasers from a gallery of whispers

New technique promises tunable laser devices

Whispering gallery mode (WGM) resonators are used to make tiny micro-lasers, sensors, switches, routers and other devices. These tiny structures rely on a...

Im Focus: Ultrafast snapshots of relaxing electrons in solids

Using ultrafast flashes of laser and x-ray radiation, scientists at the Max Planck Institute of Quantum Optics (Garching, Germany) took snapshots of the briefest electron motion inside a solid material to date. The electron motion lasted only 750 billionths of the billionth of a second before it fainted, setting a new record of human capability to capture ultrafast processes inside solids!

When x-rays shine onto solid materials or large molecules, an electron is pushed away from its original place near the nucleus of the atom, leaving a hole...

Im Focus: Quantum Sensors Decipher Magnetic Ordering in a New Semiconducting Material

For the first time, physicists have successfully imaged spiral magnetic ordering in a multiferroic material. These materials are considered highly promising candidates for future data storage media. The researchers were able to prove their findings using unique quantum sensors that were developed at Basel University and that can analyze electromagnetic fields on the nanometer scale. The results – obtained by scientists from the University of Basel’s Department of Physics, the Swiss Nanoscience Institute, the University of Montpellier and several laboratories from University Paris-Saclay – were recently published in the journal Nature.

Multiferroics are materials that simultaneously react to electric and magnetic fields. These two properties are rarely found together, and their combined...

Im Focus: Fast, convenient & standardized: New lab innovation for automated tissue engineering & drug

MBM ScienceBridge GmbH successfully negotiated a license agreement between University Medical Center Göttingen (UMG) and the biotech company Tissue Systems Holding GmbH about commercial use of a multi-well tissue plate for automated and reliable tissue engineering & drug testing.

MBM ScienceBridge GmbH successfully negotiated a license agreement between University Medical Center Göttingen (UMG) and the biotech company Tissue Systems...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

“Lasers in Composites Symposium” in Aachen – from Science to Application

19.09.2017 | Event News

I-ESA 2018 – Call for Papers

12.09.2017 | Event News

EMBO at Basel Life, a new conference on current and emerging life science research

06.09.2017 | Event News

 
Latest News

Comet or asteroid? Hubble discovers that a unique object is a binary

21.09.2017 | Physics and Astronomy

Cnidarians remotely control bacteria

21.09.2017 | Life Sciences

Monitoring the heart's mitochondria to predict cardiac arrest?

21.09.2017 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>