They Get No Kick From Cocaine
Humans often work hard to obtain drugs of abuse, and unsurprisingly, so will other animals. Mice that can give themselves intravenous doses of cocaine by pressing a lever normally show a robust behavioral response. Now, however, Francois Conquet and colleagues report that mutant mice lacking a neurotransmitter receptor called mGluR5 fail to self-administer cocaine when given the opportunity (Nature Neuroscience, Vol. 4, No. 9, Sep 01, page 873).
Interestingly, these mutant mice behaved normally when allowed to press a lever for a food reward, suggesting that their ability to learn such a behavioral task was unimpaired. Normal mice also show a strong locomotor hyperactivity in response to a single dose of cocaine, which was absent in the mutant mice. In addition, the authors show that using a drug to briefly interfere with mGluR5 function decreases cocaine self-administration in normal mice. These findings suggest that mGluR5 is critical to the behavioral effects and rewarding properties of cocaine, and suggest that this receptor system may be a promising target for addiction research.
Dr. Francois Conquet
Institut de Biologie Cellulaire et de Morphologie
rue du Bugnon 9
tel: +41 21 692 52 62
fax: +41 21 692 52 55
e-mail: francois.conquet@ibcm. unil.ch
(C) Nature Neuroscience press release.
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