1. Modulation of proorphaninFQ/N gene expression by morphine in the rat mesocorticolimbic system
- Author
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Patrizia Romualdi, Sanzio Candeletti, Daniela Landuzzi, and Claudio D'Addario
- Subjects
Male ,medicine.medical_specialty ,Gene Expression ,Striatum ,Nucleus accumbens ,Drug Administration Schedule ,Rats, Sprague-Dawley ,Mesencephalon ,Internal medicine ,Basal ganglia ,Limbic System ,medicine ,Animals ,RNA, Messenger ,Protein Precursors ,Cerebral Cortex ,Morphine ,Chemistry ,General Neuroscience ,Rats ,Analgesics, Opioid ,Ventral tegmental area ,Endocrinology ,medicine.anatomical_structure ,Opioid ,Cerebral cortex ,Receptors, Opioid ,Opiate ,Neuroscience ,medicine.drug - Abstract
We studied the effects of acute and chronic morphine treatment on proorphaninFQ/N (proOFQ/N) gene expression in the mesocorticolimbic system, known to be a reward-relevant area, of the rat CNS. Northern blot analysis revealed that a single injection of morphine 10 mg/kg i.p. increased proOFQ/N mRNA levels in nucleus accumbens, temporo-parietal cortex and in striatum. The chronic administration of the opiate caused a significant increase of proOFQ/N mRNA levels in the ventral tegmental area and a decrease in the striatum and in the nucleus accumbens. No changes were observed in the prefrontal cortex. These data indicate for the first time that morphine alters proOFQ/N gene expression in mesocorticolimbic areas, supporting the direct interaction between the opioid and OFQ/N systems and the OFQ/N involvement in morphine-rewarding mechanisms.
- Published
- 2002