BEHAVIORAL-EFFECTS OF NMDA-RECEPTOR ANTAGONISTS

NMDA receptor-antagonists were tested in dose ranges that have previou sly been found to produce anticonvulsant and anticataleptic (antiparki nsonian) effects in rats. Non-competitive NMDA receptor-antagonists ha d strong psychomotor stimulating effects, the competitive ones were we aker in this respect when given systemically. However, when locally in jected into the striatum or into the nucleus accumbens, also the compe titive NMDA-antagonists induced psychomotor stimulation. If at all, NM DA receptor-antagonists have rewarding effects, then they seem to be e licited only by the non-competitive NMDA receptor-antagonists. In maze tests, sensitive for hippocampally mediated learning, NMDA receptor-a ntagonists impaired learning. While non-competitive NMDA-antagonists p roduced learning deficits over the whole dose range tested, competitiv e ones were only effective at higher dose levels.