Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Enzyme regulates brain pathology induced by cocaine, stress

08.11.2007
Researchers have uncovered a key genetic switch that chronic cocaine or stress influences to cause the brain to descend into a pathological state.

In studies with mice they showed how chronic cocaine changes gene activity to enhance the addictive reward from the drug. And they showed similarly how chronic stress induces the same kinds of changes that hypersensitizes the brain, causing depression-like symptoms.

The researchers said their basic finding in the animals could lead to better treatments for addiction, depression and other psychiatric disorders.

Eric Nestler and colleagues published their findings in the November 8, 2007, issue of the journal Neuron, published by Cell Press.

... more about:
»Brain »HDAC5 »Stress »cocaine

In their experiments, the researchers explored how chronic cocaine or stress exerts “epigenetic” control of genes in the brain. Such control involves repressing or activating genes by altering the structure of the chromatin that enwraps genes. Specifically, the researchers explored whether chronic cocaine or stress affect an enzyme called histone deacetylase 5 (HDAC5). Normally, HDAC5 represses specific genes by removing molecules called acetyl groups from the histone proteins that make up the chromatin surrounding them. The researchers’ previous studies had shown that chronic cocaine administration in mice caused an increase in acetyl groups in a brain region called the nucleus accumbens (NAc), known to be involved in response to cocaine or stress.

The researchers’ studies showed that giving mice chronic cocaine led to a reduction in HDAC5, allowing some 172 genes to be activated. What’s more, they found that this loss of HDAC5 in the NAc made the mice more sensitive to the reward of chronic cocaine. They determined the animals’ reward-sensitivity to cocaine by measuring the mice’s preference for an area of a box that they were taught to associate with receiving cocaine.

The researchers also studied whether the animals’ adaptation to chronic stress involved HDAC5 levels. In these experiments, they exposed mice to aggressive mice and measured the resulting depressive behavior. The researchers found that such stress also reduced HDAC5 function, although through a different mechanism than for chronic cocaine.

“These data demonstrate a crucial role for HDAC5 in regulating behavioral adaptations to chronic stress as well as chronic cocaine and suggest that HDAC5 contributes to a molecular switch between acute stress responses and more long-lasting depression-like maladaptations,” wrote the researchers.

“The functions of HDAC5 described here provide new insight into the pathogenesis of drug addiction, depression, and other stress-related syndromes,” they wrote. “This fundamentally new insight into the molecular underpinnings of chronic maladaptation in brain could lead to the development of improved treatments for addiction, depression, and other chronic psychiatric disorders.”

Cathleen Genova | EurekAlert!
Further information:
http://www.cell.com

Further reports about: Brain HDAC5 Stress cocaine

More articles from Life Sciences:

nachricht World’s Largest Study on Allergic Rhinitis Reveals new Risk Genes
17.07.2018 | Helmholtz Zentrum München - Deutsches Forschungszentrum für Gesundheit und Umwelt

nachricht Plant mothers talk to their embryos via the hormone auxin
17.07.2018 | Institute of Science and Technology Austria

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: First evidence on the source of extragalactic particles

For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.

To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...

Im Focus: Magnetic vortices: Two independent magnetic skyrmion phases discovered in a single material

For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.

Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...

Im Focus: Breaking the bond: To take part or not?

Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.

A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...

Im Focus: New 2D Spectroscopy Methods

Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.

"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....

Im Focus: Chemical reactions in the light of ultrashort X-ray pulses from free-electron lasers

Ultra-short, high-intensity X-ray flashes open the door to the foundations of chemical reactions. Free-electron lasers generate these kinds of pulses, but there is a catch: the pulses vary in duration and energy. An international research team has now presented a solution: Using a ring of 16 detectors and a circularly polarized laser beam, they can determine both factors with attosecond accuracy.

Free-electron lasers (FELs) generate extremely short and intense X-ray flashes. Researchers can use these flashes to resolve structures with diameters on the...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Leading experts in Diabetes, Metabolism and Biomedical Engineering discuss Precision Medicine

13.07.2018 | Event News

Conference on Laser Polishing – LaP: Fine Tuning for Surfaces

12.07.2018 | Event News

11th European Wood-based Panel Symposium 2018: Meeting point for the wood-based materials industry

03.07.2018 | Event News

 
Latest News

Behavior-influencing policies are critical for mass market success of low carbon vehicles

17.07.2018 | Power and Electrical Engineering

Plant mothers talk to their embryos via the hormone auxin

17.07.2018 | Life Sciences

Subaru Telescope helps pinpoint origin of ultra-high energy neutrino

16.07.2018 | Physics and Astronomy

VideoLinks
Science & Research
Overview of more VideoLinks >>>