RT Journal Article SR Electronic T1 Precipitated morphine withdrawal stimulates multiple activator protein-1 signaling pathways in rat brain. JF Molecular Pharmacology JO Mol Pharmacol FD American Society for Pharmacology and Experimental Therapeutics SP 29 OP 39 VO 47 IS 1 A1 P Couceyro A1 J Douglass YR 1995 UL http://molpharm.aspetjournals.org/content/47/1/29.abstract AB Morphine dependence is a long lasting form of neuronal plasticity. Naloxone-precipitated morphine withdrawal, a model of opioid dependence, induces brain region-specific changes in activator protein-1 (AP-1) transcription factor gene expression. Rapid increases in c-fos, fos-B, jun-B, and c-jun mRNA levels accompany withdrawal, with the relative level of induction correlating with the severity of physical dependence. Altered patterns of c-fos mRNA expression were limited to neuronal circuits mediating stress responses, motivation, and cognition. AP-1 DNA-binding activity and dimer composition also exhibited regulation after withdrawal, presumably as a result of both transcriptional and post-translational events. Thus, morphine dependence results in the alteration of diverse, brain region-specific, signal transcription pathways involving AP-1 transcription factors.