Expression of c-fos protein by N-methyl-D-aspartic acid in hypothalamus of immature female rats: blockade by MK-801 or neonatal treatment with monosodium glutamate.

Significant NMDA-induced cellular activity in the median eminence-arcuate region of immature female rats was immunocytochemically localized via c-fos protein-like immunoreactivity. The production of this protein was completely prevented by pre-injection of MK-801 or APV, antagonists of the NMDA receptor-coupled ion channel. Treatment of newborn rats with monosodium glutamate (MSG), which destroys glutamate-sensitive neurons, significantly attenuated NMDA-induced c-fos when tested in the peripubertal period. These results implicate NMDA receptors in the expression of c-fos protein-like immunoreactivity in cells of the arcuate nucleus-median eminence of immature female rats.