MK-801 interferes with the acquisition of amphetamine- and lithium-induced place conditioning

The place conditioning paradigm was used to assess the ability of the noncompetitive NMDA receptor antagonist, MK-801, to interfere with drug-place associations. MK-801 (0.1 mg/kg, i.p.) attenuated a place preference produced by high, but not low to moderate, doses of amphetamine. Interference with amphetamine place preference learning was not the result of state-dependent retrieval produced by MK-801. Furthermore, MK-801 did not interfere with the expression of a previously established amphetamine place preference. Pretreatment with MK-801 also interfered with lithium-induced conditioned place aversion learning. These results suggest that the attenuation of place preference conditioning produced by MK-801 is the result of its interference with learning rather than with the rewarding properties of drugs.