MK-801 INHIBITS THE INDUCTION OF IMMEDIATE-EARLY GENES IN CEREBRAL-CORTEX, THALAMUS, AND HIPPOCAMPUS, BUT NOT IN SUBSTANTIA-NIGRA FOLLOWINGMIDDLE CEREBRAL-ARTERY OCCLUSION

Middle cerebral artery (MCA) occlusion in rats induced c-fos and junB mRN ~ t h later in all ipsilateral cortex outside the MCA distribution and in many subcortical structures: medial striatum; most of thalamus including medial and lateral geniculate nuclei; substantia nigra; and hippocampus. The N-methyl-D-aspartate (NMDA) antagonist, MK-801 (4 mg /kg, i.p.) inhibited c-fos and junB mRNA induction in the cortex, stri atum, thalamus, and hippocampus but not in the substantia nigra. These data show that c-fos and junB mRNA induction in cortex, striatum, tha lamus, hippocampus involves the activation of NMDA receptors whereas d ifferent receptors must be implicated in the induction in substantia n igra.