The long range goals of this proposal are to better understand how neural activity regulates opioid gene expression, and to understand how this process contributes to environmental- and drug-induced changes in the nervous system. A better understanding of these processes will help to define the adaptive biochemical changes underlying addiction, dependence, and drug-seeking behaviors. The primary objectives of this research proposal have not changed but have been modified as our research has progressed over the pst few years. The major focus is to characterize the interaction of intracellular signaling pathways with several different transcription factors complexes that mediate activity-dependent regulation of proenkephalin gene expression via their interaction with a well characterized second messenger inducible DNA enhancer. Studies will focus on defining components of the AP-1, ATF, and CREB nucleoprotein complexes involved in the regulation of proenkephalin transcription. Functional and biochemical interactions with the proenkephalin inducible DNA enhancer and signals transmitted through intracellular signaling pathways will be investigated. Recent findings indicate that growth and neurotrophic factors activate proenkephalin transcription via a novel ras-dependent signaling pathway that results in CREB phosphorylation at Ser-133. Based upon these discoveries we have increased our emphasis on further characterization of this pathway in order to further understand the role of this pathway in neural signaling and proenkephalin gene regulation.