INHIBITION OF NFKB DNA-BINDING ACTIVITY BY GLUCOCORTICOIDS IN RAT-BRAIN

The influence of glucocorticoids on the transcription factor NFkB was investigated by using the gel mobility shift assay with nuclear extrac ts prepared from rat cerebral cortex and hippocampus after a variety o f in vivo treatments. Following stimulation with each of three treatme nts, kainate, pilocarpine, or lithium plus pilocarpine-induced seizure s, NFkB DNA binding activity was significantly greater in the cortex a nd hippocampus from adrenalectomized than from adrenal-intact rats. Th ese results indicate that in rat brain glucocorticoids inhibit NfkB ac tivity in addition to the previously reported inhibition of the transc ription factor AP-1 (activator protein 1). Impairment of stimulus-indu ced transcription factor activity may contribute to the deleterious ef fects of prolonged elevations of glucocorticoids on neuronal function.