PERIPHERAL NOXIOUS-STIMULATION INDUCES CREM EXPRESSION IN DORSAL HORN- INVOLVEMENT OF GLUTAMATE

Peripheral noxious stimulation is known to trigger signalling cascades in neurons of the spinal cord. The response to pain and stress at the level of gene expression involves transcriptional activation of sever al cyclic AMP responsive genes. Here, we show induction of the CREM (c yclic-AMP responsive element modulator) gene in distinct subpopulation s of spinal cord neurons upon thermal noxious stimulation. The additio n of forskolin or glutamate to cultured spinal cord neurons results in the induction of the CREM isoform, ICER (Inducible cyclic-AMP Early R epressor), a powerful repressor of cAMP-induced transcription. Overexp ression of ICER in cultured spinal cord neurons results in the repress ion of the c-fos and c-jun promoters induced by forskolin and glutamat e. On this basis, we postulate that early activation of ICER in spinal cord participates in the attenuation of early gene induction followin g noxious stimulation.