| Abstract: | The mRNA expression pattern for four different immediate early genes was examined dynamically in rat brain after administration of phencyclidine (PCP; 0.86 or 8.6 mg/kg) or MK801 (0.1 or 1.0 mg/kg). Following each treatment, the expression of cfos, cjun, junB, and zif268 mRNA changed distinctively and dynamically between 1 and 48 hours. cfos mRNA was induced in cortical areas at early times after either dose of PCP or of MK801; the change was especially prominent in cingulate and auditory cortices. zif268 mRNA showed an early (1 hour) activation and a delayed (24–48 hour) suppression after PCP and MK801 in neocortical areas. PCP also caused cjun and junB mRNA induction in cortical areas at early times, with a distribution and time course similar to its effects on cfos mRNA. No alterations in cfos, cjun, or junB mRNA were found in neocortical or hippocampal areas at any delayed time (>6 hours) after PCP treatment, whereas suppression of zif268 expression was prominent even at 48 hours post-treatment. CPP, a competitive NMDA antagonist, showed a similar pattern of effects on cfos and zif268 mRNA expression. These functional consequences of a PCP- or MK801-induced reduction in NMDA-sensitive glutamate transmission may be relevant to an understanding of animal NMDA pharmacology and/or to clinical psychotomimetic side effects of antiglutamatergic treatments. Synapse 29:14–28, 1998. © 1998 Wiley-Liss, Inc. |
