RT Journal Article T1 Transcriptomic integration of D4R and MOR signaling in the rat caudate putamen. A1 Valderrama-Carvajal, Alejandra A1 Irizar, Haritz A1 Gago, Belen A1 Jimenez-Urbieta, Haritz A1 Fuxe, Kjell A1 Rodriguez-Oroz, Maria C A1 Otaegui, David A1 Rivera, Alicia K1 Analgesics K1 Benzamides K1 Dopamine agonists K1 Rats K1 Receptors AB Morphine binding to opioid receptors, mainly to μ opioid receptor (MOR), induces alterations in intracellular pathways essential to the initial development of addiction. The activation of the dopamine D4 receptor (D4R), which is expressed in the caudate putamen (CPu), mainly counteracts morphine-induced alterations in several molecular networks. These involve transcription factors, adaptive changes of MOR signaling, activation of the nigrostriatal dopamine pathway and behavioural effects, underlining functional D4R/MOR interactions. To shed light on the molecular mechanisms implicated, we evaluated the transcriptome alterations following acute administration of morphine and/or PD168,077 (D4R agonist) using whole-genome microarrays and a linear regression-based differential expression analysis. The results highlight the development of a unique transcriptional signature following the co-administration of both drugs that reflects a countereffect of PD168,077 on morphine effects. A KEGG pathway enrichment analysis using GSEA identified 3 pathways enriched positively in morphine vs control and negatively in morphine + PD168,077 vs morphine (Ribosome, Complement and Coagulation Cascades, Systemic Lupus Erythematosus) and 3 pathways with the opposite enrichment pattern (Alzheimer's Disease, Neuroactive Ligand Receptor Interaction, Oxidative Phosphorilation). This work supports the massive D4R/MOR functional integration at the CPu and provides a gateway to further studies on the use of D4R drugs to modulate morphine-induced effects. PB Springer Nature YR 2018 FD 2018-04-20 LK http://hdl.handle.net/10668/12440 UL http://hdl.handle.net/10668/12440 LA en NO Valderrama-Carvajal A, Irizar H, Gago B, Jiménez-Urbieta H, Fuxe K, Rodríguez-Oroz MC, et al. Transcriptomic integration of D4R and MOR signaling in the rat caudate putamen. Sci Rep. 2018 May 9;8(1):7337 NO This work was supported by the Junta de Andalucía grant (CTS-0161) and Universidad de Málaga. Dr. Valderrama-Carvajal’s work has been funded by a Junta de Andalucía Ph.D. Studentship Grant. Dr Irizar and Haritz Jiménez-Urbieta were supported by a Gobierno Vasco Ph.D. Studentship Grant. DS RISalud RD Apr 10, 2025