Reserpine potentiates NMDA-induced c-fos mRNB expression in the mouse brain

The systemic administration of a non-convulsant dose of N-methyl-D-aspartate (NMDA; 75 mg/kg i.p.), which was associated with motor activation, induced a regional c-fos mRNA expression in the mouse brain. The NMDA-induced c-fos mRNA expression was predominant in the dentate gyms and in the medial mammillary nucleus and less pronounced in other hippocampal 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 hypothesized dopamine-independent NMDA-mediated motor activation mechanism. No increase in c-fos mRNA expression was observed 21 h after reserpine treatment (5 mg/kg s.c.). However, reserpinization induced a significant potentiation of the NMDA-induced c-fos mRNA expression. These results show the existence of a strong and selective amine-dependent modulation of NMDA neurotransmission in the brain.