9 research outputs found
Evaluating assumptions of scales for subjective assessment of thermal environments – Do laypersons perceive them the way, we researchers believe?
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Baclofen antagonizes intravenous self-administration of nicotine in mice and rats
No full textAims: gamma-Aminobutyric acid (GABA)-ergic transmission plays an important role in modulating reinforcing effects of different drugs of misuse. In particular, stimulation of GABA(B) receptors negatively influences self-administration of cocaine, heroin, nicotine, alcohol and gamma-hydroxybutyric acid. The effect and specificity of the GABA(B) agonist baclofen on nicotine misuse were studied on two animal models of self-administration. Methods: The effects of RS baclofen and the two isomers R baclofen and S baclofen were studied on the acute nicotine self-administration in drug-naive mice. The effect of RS baclofen was also studied in rats trained to chronically self-administer nicotine under a continuous reinforcement (FR1) schedule. Results: RS baclofen antagonizes nicotine intravenous self-administration at doses of 1.25-2.5 mg/kg intraperitoneally (i.p.). Furthermore, this effect is sterospecific. R baclofen completely prevented nicotine self-administration at the dose of 0.625 mg/kg i.p., whereas S baclofen was inactive up to the dose of 2.5 mg/kg i.p. In rats trained to self-administer nicotine, pretreatment with RS baclofen at the dose of 2.5 mg/kg i.p. significantly increased the rate of responding for nicotine. This effect was similar to the effect obtained when rats were pretreated with the nicotine central receptor antagonist mecamylamine (1 mg/kg i.p.). Conclusions: These data show that baclofen is able to antagonize nicotine-rewarding effects in mice and rats and suggest its potential clinical utility for the treatment of nicotine misuse
Gamma-hydroxybutyric acid: an evaluation of its rewarding properties in rats and mice
No full textGamma-hydroxybutyric acid, an endogenous compound present in mammalian brain and supposed to be a neurotransmitter or neuromodulator, has been shown to affect several aspects of dependence from some drugs of abuse. It has been successfully used in clinical practice to alleviate both alcohol and opiate withdrawal symptoms. The aim of this study was to investigate whether gamma-hydroxybutyric acid possesses rc warding properties by means of conditioned place preference and intravenous self-administration paradigms. In the present study, gamma-hydroxybutyric acid induced conditioned place preference in rats, was intravenously self-administered by drug naive mice, and altered cocaine intravenous self-administration in rats. Although to date the physiological role of this compound still re mains unclear, there is no doubt that gamma-hydroxybutyric acid, in addition to its proved effect on alcohol and opiate dependence, possesses reinforcing properties of its own and may interfere with the neurochemical events in the rewarding effects produced by psychostimulant drugs. Our investigation points out the abuse: liability of this drug, suggesting the use of particular precaution in handling gamma-hydroxybutyric acid as a clinically useful drug. (C) 2000 Elsevier Science Inc. All rights: reserved
