[The effect of the NMDA-receptor antagonist (+/-)-CPP on the conditioned-reflex activation of an operant reaction in the brain electrical self-stimulation test in rats].

Self-stimulation behaviour was studied in rats with implanted bipolar electrodes in ventral tegmental area (VTA) and guide cannulae in nuclei accumbens septi (NAC). Conditioned activation of the operant response was induced by the stimuli associated with rewarding electrical stimulation of VTA, i.e., light or subthreshold stimulation. Bilateral administration of NMDA receptor antagonist ( +/- )-CPP (2.5 mcg in each cannula) significantly attenuated the facilitating effect of the conditioned stimuli. These data provide evidence for the role of glutamatergic transmission in NAC in realization of responses with conditioned reinforcement.