Magnesium-induced conditioned place preference in mice.
A conditioned place preference procedure was used in mice to test the hypothesis that magnesium possesses reinforcing properties. Mice were conditioned to the nonpreferred end of a three-compartment straight shuttle box with MgCl2 injections alternating with saline injections on the preferred end. Dose of MgCl2 was varied (0, 15, 30, 125 mg/kg) as well as number of conditioning trials (8 or 16). On the day after the first postconditioning test, animals were given acute injections of 5 mg/kg cocaine, or other test drug, to determine if the conditioned effect on behavior would be potentiated, maintained or blocked by these test drugs. Results demonstrated that 15 mg/kg MgCl2 induced the greatest amount of conditioning and that increasing the number of MgCl2/place pairings did not enhance the amount of conditioning, but rather, it decreased it. Amphetamine potentiated MgCl2-induced place preference; cocaine and pentobarbital maintained it; and haloperidol blocked it. These data indicate that MgCl2 has some primary reinforcing properties in mice and that MgCl2 shares stimulus properties with other stimulants and reinforcing substances.
Lawley
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Department of Psychology, Boston University, MA 02115.
Kantak
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KM
D000818:Animals; D003042:Cocaine / Q000494:pharmacology; D003213:Conditioning, Psychological / Q000187:drug effects*; D003913:Dextroamphetamine / Q000494:pharmacology; D005795:Generalization, Stimulus; D006220:Haloperidol / Q000494:pharmacology; D008274:Magnesium / Q000494:pharmacology*; D008297:Male; D051379:Mice; D010424:Pentobarbital / Q000494:pharmacology; D012054:Reinforcement, Psychology; D013997:Time Factors
D008274:Magnesium; D010424:Pentobarbital; D003042:Cocaine; D006220:Haloperidol; D003913:Dextroamphetamine