Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Scripps Research scientists find key mechanism in transition to alcohol dependence

01.06.2011
Finding could lead to development of drugs that decrease heavy alcohol consumption

A team of Scripps Research Institute scientists has found a key biological mechanism underpinning the transition to alcohol dependence. This finding opens the door to the development of drugs to manage excessive alcohol consumption.

"Our focus in this study, like much of our lab's research, was to examine the role of the brain's stress system in compulsive alcohol drinking driven by the aversive aspects of alcohol withdrawal," said Scripps Research Associate Professor Marisa Roberto, Ph.D., senior author of the study.

"A major goal for this study," added Research Associate Nicholas Gilpin, Ph.D., the paper's first author, "was to determine the neural circuitry that mediates the transition to alcohol dependence."

In the new research, published in the June 1, 2011 issue of the journal Biological Psychiatry, the Scripps Research scientists demonstrated the key role of a receptor —a structure that binds substances, triggering certain biological effects—for neuropeptide Y in a part of the brain known as the central amygdala. The amygdala, a group of nuclei deep within the medial temporal lobes, performs an important role in the processing and memory of emotional reactions.

"We've known for quite some time that neuropeptide Y is an endogenous [naturally occurring] anti-stress agent," says Markus Heilig, clinical director of the National Institute of Alcohol Abuse and Alcoholism (NIAAA). "We've also known that development of alcohol dependence gives rise to increased sensitivity to stress. This paper elegantly and logically brings these two lines of research together. It supports the idea that strengthening neuropeptide Y transmission in the amygdala would be an attractive treatment for alcoholism. The challenge remains to develop clinically useful medications based on this principle."

Discovering the Circuitry

Building on Gilpin's previous work on neuropeptide Y, in the new project, Gilpin, Roberto, and colleagues observed the effects of the administration neuropeptide Y in the central amygdala on alcohol drinking in rats. Alcohol-dependent rats were allowed to press levers for ethanol and water during daily withdrawal from chronic alcohol exposure.

"Normally, the transition to alcohol dependence is accompanied by gradually escalating levels of alcohol consumption during daily withdrawals," Gilpin explained. "The aim of this protocol was to examine whether neuropeptide Y infusions during daily withdrawals would block this escalation of alcohol drinking."

The scientists report a suppression of alcohol consumption with chronic neuropeptide Y infusions and detailed some of the neurocircuitry involved. Ethanol normally produces robust increases in inhibitory GABAergic transmission—GABA is another neurotransmitter—in the central amygdala, but this effect is blocked and reversed by neuropeptide Y.

Gilpin notes the scientists were surprised at one aspect of the findings—the role of a subset of neuropeptide Y receptors known as Y2 receptors. "Previous behavioral evidence suggested that antagonism of Y2 receptors in whole brain suppresses alcohol drinking, similar to the effects of neuropeptide Y," he said. "However, our data suggest that Y2 receptor blockade in central amygdala might actually increase alcohol drinking, presumably by affecting pre-synaptic release of GABA. These data also suggest that antagonism of post-synaptic Y1 receptors in central amygdala provides a viable pharmacotherapeutic strategy, a hypothesis supported by previous work from other labs."

Two additional aspects of the findings are worth noting, Roberto says. First, repeated neuropeptide Y administration not only blocked the development of excessive alcohol consumption in dependent rats, but also tempered the moderate increase in alcohol consumption following periods of abstinence in non-dependent rats. Second, neuropeptide Y exhibited long-term efficacy in suppressing alcohol self-administration, highlighting the potential of neuropeptide Y treatments for a clinical setting.

In addition to Roberto and Gilpin, authors of this paper, titled "Neuropeptide Y Opposes Alcohol Effects on GABA Release in Amygdala and Blocks the Transition to Alcohol Dependence" and scheduled to appear in the June 1, 2011 print edition of Biological Psychiatry, include Kaushik Misra, Melissa Herman, Maureen Cruz, and George Koob, all of Scripps Research. See http://www.ncbi.nlm.nih.gov/pubmed/21459365 .

This project was supported by the National Institutes of Health's National Institute on Alcohol Abuse and Alcoholism, and the Pearson Center for Alcoholism and Addiction Research at Scripps Research.

About The Scripps Research Institute

The Scripps Research Institute is one of the world's largest independent, non-profit biomedical research organizations. Scripps Research is internationally recognized for its discoveries in immunology, molecular and cellular biology, chemistry, neuroscience, and vaccine development, as well as for its insights into autoimmune, cardiovascular, and infectious disease. Headquartered in La Jolla, California, the institute also includes a campus in Jupiter, Florida, where scientists focus on drug discovery and technology development in addition to basic biomedical science. Scripps Research currently employs about 3,000 scientists, staff, postdoctoral fellows, and graduate students on its two campuses. The institute's graduate program, which awards Ph.D. degrees in biology and chemistry, is ranked among the top ten such programs in the nation. For more information, see www.scripps.edu.

Mika Ono | EurekAlert!
Further information:
http://www.scripps.edu

More articles from Health and Medicine:

nachricht One gene closer to regenerative therapy for muscular disorders
01.06.2017 | Cincinnati Children's Hospital Medical Center

nachricht The gut microbiota plays a key role in treatment with classic diabetes medication
01.06.2017 | University of Gothenburg

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

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

Im Focus: Can we see monkeys from space? Emerging technologies to map biodiversity

An international team of scientists has proposed a new multi-disciplinary approach in which an array of new technologies will allow us to map biodiversity and the risks that wildlife is facing at the scale of whole landscapes. The findings are published in Nature Ecology and Evolution. This international research is led by the Kunming Institute of Zoology from China, University of East Anglia, University of Leicester and the Leibniz Institute for Zoo and Wildlife Research.

Using a combination of satellite and ground data, the team proposes that it is now possible to map biodiversity with an accuracy that has not been previously...

Im Focus: Climate satellite: Tracking methane with robust laser technology

Heatwaves in the Arctic, longer periods of vegetation in Europe, severe floods in West Africa – starting in 2021, scientists want to explore the emissions of the greenhouse gas methane with the German-French satellite MERLIN. This is made possible by a new robust laser system of the Fraunhofer Institute for Laser Technology ILT in Aachen, which achieves unprecedented measurement accuracy.

Methane is primarily the result of the decomposition of organic matter. The gas has a 25 times greater warming potential than carbon dioxide, but is not as...

Im Focus: How protons move through a fuel cell

Hydrogen is regarded as the energy source of the future: It is produced with solar power and can be used to generate heat and electricity in fuel cells. Empa researchers have now succeeded in decoding the movement of hydrogen ions in crystals – a key step towards more efficient energy conversion in the hydrogen industry of tomorrow.

As charge carriers, electrons and ions play the leading role in electrochemical energy storage devices and converters such as batteries and fuel cells. Proton...

Im Focus: A unique data centre for cosmological simulations

Scientists from the Excellence Cluster Universe at the Ludwig-Maximilians-Universität Munich have establised "Cosmowebportal", a unique data centre for cosmological simulations located at the Leibniz Supercomputing Centre (LRZ) of the Bavarian Academy of Sciences. The complete results of a series of large hydrodynamical cosmological simulations are available, with data volumes typically exceeding several hundred terabytes. Scientists worldwide can interactively explore these complex simulations via a web interface and directly access the results.

With current telescopes, scientists can observe our Universe’s galaxies and galaxy clusters and their distribution along an invisible cosmic web. From the...

Im Focus: Scientists develop molecular thermometer for contactless measurement using infrared light

Temperature measurements possible even on the smallest scale / Molecular ruby for use in material sciences, biology, and medicine

Chemists at Johannes Gutenberg University Mainz (JGU) in cooperation with researchers of the German Federal Institute for Materials Research and Testing (BAM)...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Plants are networkers

19.06.2017 | Event News

Digital Survival Training for Executives

13.06.2017 | Event News

Global Learning Council Summit 2017

13.06.2017 | Event News

 
Latest News

Quantum thermometer or optical refrigerator?

23.06.2017 | Physics and Astronomy

A 100-year-old physics problem has been solved at EPFL

23.06.2017 | Physics and Astronomy

Equipping form with function

23.06.2017 | Information Technology

VideoLinks
B2B-VideoLinks
More VideoLinks >>>