RAPID AND SELECTIVE ENHANCEMENT OF DNA-BINDING ACTIVITY OF THE TRANSCRIPTION FACTOR AP1 BY SYSTEMIC ADMINISTRATION OF N-METHYL-D-ASPARTATE IN MURINE HIPPOCAMPUS

Brain nuclear extracts of ddY mice contained 3 different transcription factors with leucine-zipper domains, including activator protein-1 (A P1), cyclic AMP responsive element binding protein (CREB) and Myc. An intraperitoneal injection of N-methyl-D-aspartate (NMDA) was effective in selectively inducing 6-fold enhancement of DNA binding activity of AP1 in the hippocampus 2 h after the administration. Furthermore, NMD A induced less than 2-fold potentiation of the AP1 binding in the stri atum, hypothalamus, medulla-pons and cerebral cortex in a rank order o f decreasing magnitude. However, the AP1 binding was not significantly affected by the systemic injection of NMDA in the midbrain and cerebe llum In contrast, NMDA virtually did not alter DNA binding activities of both CREB and Myc in discrete structures of murine brain under simi lar experimental conditions. These results suggest that the systemic a dministration of NMDA may induce rapid and selective enhancement of DN A binding activity of AP1 in murine hippocampus.