Using genetic engineering, researchers headed by Professor Dr. Günther Schütz 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 für Seelische Gesundheit, ZI) in Mannheim and the research group of Professor Dr. Christian Lüscher 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 If control animals withdrawn from cocaine are readministered the drug after some time, addictive behavior and drug seeking are reactivated.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.
So find a drug that will suppress NR1 in humans and maybe kicking coke addiction would become a lot easier.
Blocking the gene NR1 and activating the gene GluR1 might extinguish cocaine addiction.
"It is fascinating to observe how individual proteins can determine addictive behavioral patterns," says Günther Schütz, 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."
Imagine a person genetically engineered with an assortment of genes that can be turned on and off to cause changes in behavior. Genetically engineered soldiers could be given a compound in their drinks that turn them alternatively docile in peace time or aggressive for training or war time. Or some really rich guy could pay surrogate parents to raise a genetically engineered daughter who could be made to fall in love with and be totally loyal to whoever she was exposed to after eating a dinner with a special compound in it. The possibilities are endless.
Or how about this: an injectable gene therapy that will cause a person become more easily manipulated to switch loyalties. Spies could kidnap someone and turn them against their nation.
|Share |||Randall Parker, 2008 August 21 10:55 PM Brain Addiction|