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.
|Contact: Dr. Sibylle Kohlstdt|
Helmholtz Association of German Research Centres