Navigation Links
Cocaine: How addiction develops
Date:8/21/2008

Permanent drug seeking and relapse after renewed drug administration are typical behavioral patterns of addiction. Molecular changes at the connection points in the brain's reward center are directly responsible for this. This finding was published by a research team from the Institute of Mental Health (ZI) in Mannheim, the German Cancer Research Center (DKFZ) in Heidelberg and the University of Geneva, Switzerland, in the latest issue of Neuron. The results provide researchers with new approaches in the medical treatment of drug addiction.

Addiction leaves detectable traces in the brain: In particular regions of the central nervous system, which produce the messenger substance dopamine, the drug cocaine causes molecular restructuring processes at the synapses, the points of connection between two neurons. As a reaction to the drug, protein subunits are exchanged in specific receptor complexes. As a result, the modified synapse becomes able to transmit nervous signals with enhanced strength a phenomenon that has been termed 'drug-induced synaptic plasticity'. Researchers have suspected for many years that drug-induced synaptic plasticity plays a crucial role in addiction development. However, this hypothesis has not yet been proven experimentally.

Using genetic engineering, researchers headed by Professor Dr. Gnther Schtz at the German Cancer Research Center (Deutsches Krebsforschungszentrum, DKFZ) have now been able to selectively switch off those protein components in dopamine-producing neurons that are integrated into the receptor complexes under the influence of cocaine. Jointly with the team of Professor Dr. Rainer Spanagel at the Central Institute of Mental Health (Zentralinstitut fr Seelische Gesundheit, ZI) in Mannheim and the research group of Professor Dr. Christian Lscher at Geneva University, the Heidelberg researchers studied the changes in physiology and behavior of the genetically modified animals.

The scientists performed standardized tests to measure addictive behavior in the animals. At first sight, both the genetically modified and the control animals displayed the usual behavior under the influence of cocaine. Forced to increase their agility, the lab animals covered significantly greater running distances and preferentially frequented those places where they had been conditioned to be regularly administered the drug.

If normal mice do not find drugs at the familiar places over a longer period of time, their addictive behavior and preference for the cocaine-associated places subside. However, this is not true for animals whose receptor subunit GluR1 has been switched off: These mice invariably frequent the places where they expect to find the drug, i.e., their addictive behavior persists.

Mice whose NR1 protein has been switched off have surprised scientists with a different conspicuous behavior. If control animals withdrawn from cocaine are readministered the drug after some time, addictive behavior and drug seeking are reactivated. In contrast, NR1 deficient animals proved to be resistant to relapsing into the addiction.

"It is fascinating to observe how individual proteins can determine addictive behavioral patterns," says Gnther Schtz, and his colleague Rainer Spanagel adds: "In addition, our results open up whole new prospects for treating addiction. Thus, blocking the NR1 receptor might protect from relapsing into addiction. Selective activation of GluR1 would even contribute to 'extinguishing' the addiction."


'/>"/>

Contact: Dr. Sibylle Kohlstdt
s.kohlstaedt@dkfz.de
Helmholtz Association of German Research Centres
Source:Eurekalert

Related biology news :

1. Nicotinic receptors may be important targets for treatment of multiple addictions
2. New genetic research into nicotine addiction shows promise for personalized treatment
3. Can plant-based ethanol save us from our fossil fuel addiction?
4. Cognitive, genetic clues identified in imaging study of alcohol addiction
5. Hungry mothers risk addiction in their adult children
6. Corals addiction to junk food
7. Erasing drug-associated memories may stop drug addiction relapses
8. Large-scale investment catapults CAMHs mental illness and addiction research forward
9. How schizophrenia develops: Major clues discovered
10. MIT develops tractor beam for cells, more
11. Team of scientists develops non-invasive method to track nerve-cell development in live human brain
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:4/26/2016)... and LONDON , ... Finacle, part of EdgeVerve Systems, a product subsidiary ... Onegini today announced a partnership to integrate the ...      (Logo: http://photos.prnewswire.com/prnh/20151104/283829LOGO ) ... provide their customers enhanced security to access and ...
(Date:4/19/2016)... DUBAI , UAE, April 20, 2016 ... can be implemented as a compact web-based "all-in-one" system ... in the biometric fingerprint reader or the door interface ... requirements of modern access control systems. The minimal dimensions ... the ID readers into the building installations offer considerable ...
(Date:4/15/2016)... 2016 Research and Markets has ... Market 2016-2020,"  report to their offering.  , ... ,The global gait biometrics market is expected to ... period 2016-2020. Gait analysis generates multiple ... used to compute factors that are not or ...
Breaking Biology News(10 mins):
(Date:4/29/2016)... CA (PRWEB) , ... April 29, 2016 , ... Summit ... (NSCF) to support the development of a patient-specific stem cell therapy for the treatment ... the lab of Dr. Jeanne Loring at The Scripps Research Institute in San Diego, ...
(Date:4/29/2016)... , April 29, 2016 Elekta ... latest update to its industry-leading treatment planning software, is ... Monaco version 5.11 provides significant ... attain calculation speeds up to four times faster than ... With the industry,s gold standard Monte Carlo ...
(Date:4/28/2016)... NEW YORK , April 28, 2016 /PRNewswire/ ... biotechnology acceleration company reports the Company,s CEO  was ... capital titled Accelerators Enter When VCs Fear To ... Life Science Leader magazine is an ... work for everything from emerging biotechs to Big ...
(Date:4/28/2016)... ... April 28, 2016 , ... Next week on May ... its first-in-class technologies for tissue stem cell counting and expansion to gene-editing scientists ... Reprogramming & CRISPR-based Genome Engineering in Burlington, Massachusetts. , The attention of most ...
Breaking Biology Technology: