Morphine dependence is associated with changes in neuropeptide S receptor expression and function in rat brain
Pasha Ghazal1, Roberto Ciccocioppo, Massimo Ubaldi
1School of Pharmacy, Pharmacology Unit, University of Camerino, Via Madonna delle Carceri, 62032 Camerino, Italy.
Peptides
|May 21, 2013
Summary
Morphine withdrawal alters Neuropeptide S Receptor (NPSR) gene expression in rat brains, increasing anxiety. Neuropeptide S (NPS) administration reduced this anxiety during protracted abstinence.
Area of Science:
- Neuroscience
- Pharmacology
- Molecular Biology
Background:
- Neuropeptide S (NPS) is a ligand for the G-protein coupled receptor NPSR.
- NPSR gene expression changes during ethanol withdrawal.
- Opioid withdrawal and protracted abstinence effects on NPSR are not well understood.
Purpose of the Study:
- To investigate NPSR gene expression changes during morphine withdrawal and protracted abstinence.
- To assess anxiety levels and NPS-induced anxiolytic effects during morphine abstinence.
Main Methods:
- Morphine dependence was induced in Wistar rats over 7 days.
- NPSR mRNA expression was analyzed using in situ hybridization (ISH) at 12 hours and 7 days post-morphine.
- Anxiety was assessed using the elevated plus maze (EPM), and NPS anxiolytic effects were tested.
Main Results:
- Morphine treatment induced significant withdrawal symptoms.
- NPSR mRNA expression changed in the ventral tegmental area (12h) and basolateral amygdala/bed nucleus of stria terminalis (7 days).
- Animals exhibited increased anxiety 7 days into abstinence, which was reduced by NPS administration.
Conclusions:
- Morphine dependence alters NPSR mRNA expression in specific brain regions.
- Protracted abstinence from morphine is associated with heightened anxiety.
- NPS exhibits potent anxiolytic-like effects during morphine abstinence, suggesting a therapeutic role.
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