Abstract
I.c.v. self-administration of MDMA (0.01-2 micro g per infusion), alone and in combination with CP 55,940 (0.4 micro g infusion(-1)), was studied on an operant responding procedure. On the basis of individual preference for one of two levers, developed during training, rats were allowed to self-administer vehicle from the preferred lever and MDMA from the other. Pressings on the MDMA associated-lever, except for the maximal unit dose, progressively increased. The combination of CP 55,940 with MDMA (1 micro g infusion(-1)) reduced the number of drug-associated lever pressings compared to the single drugs. Pre-treatment with SR 141716A (0.5 mg kg(-1) i.p.), 15 min before each daily session, significantly increased MDMA self-administration. These findings suggest that MDMA self-administration is under endogenous tonic control by the endocannabinoid system.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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Animals
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Cannabinoid Receptor Modulators
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Cannabinoids / antagonists & inhibitors
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Cannabinoids / metabolism*
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Conditioning, Operant / drug effects
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Cyclohexanols / pharmacology
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Dose-Response Relationship, Drug
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Endocannabinoids
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Fatty Acids, Unsaturated / antagonists & inhibitors
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Fatty Acids, Unsaturated / metabolism*
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Hallucinogens / administration & dosage
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Hallucinogens / pharmacology*
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Injections, Intraventricular
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Male
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N-Methyl-3,4-methylenedioxyamphetamine / administration & dosage
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N-Methyl-3,4-methylenedioxyamphetamine / pharmacology*
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Piperidines / pharmacology
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Pyrazoles / pharmacology
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Rats
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Rats, Wistar
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Reinforcement, Psychology
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Rimonabant
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Self Administration
Substances
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Cannabinoid Receptor Modulators
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Cannabinoids
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Cyclohexanols
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Endocannabinoids
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Fatty Acids, Unsaturated
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Hallucinogens
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Piperidines
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Pyrazoles
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3-(2-hydroxy-4-(1,1-dimethylheptyl)phenyl)-4-(3-hydroxypropyl)cyclohexanol
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N-Methyl-3,4-methylenedioxyamphetamine
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Rimonabant