RESERPINE POTENTIATES NMDA-INDUCED C-FOS MRNB EXPRESSION IN THE MOUSE-BRAIN

The systemic administration of a non-convulsant dose of N-methyl-D-asp artate (NMDA; 75 mg/kg i.p.), which was associated with motor activati on, induced a regional c-fos mRNA expression in the mouse brain. The N MDA-induced c-fos mRNA expression was predominant in the dentate gyms and in the medial mammillary nucleus and less pronounced in other hipp ocampal areas, cortical areas, bed nucleus of the stria terminalis and posterior amygdaloid nuclei. It is suggested that the hippocampus and /or the extended amygdala might be involved in the previously hypothes ized dopamine-independent NMDA-mediated motor activation mechanism. No increase in c-fos mRNA expression was observed 21 h after reserpine t reatment (5 mg/kg s.c.). However, reserpinization induced a significan t potentiation of the NMDA-induced c-fos mRNA expression. These result s show the existence of a strong and selective amine-dependent modulat ion of NMDA neurotransmission in the brain.