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Published on: November 6, 2018
Immediate withdrawal from chronic "binge" cocaine administration increases mu-opioid receptor mRNA levels in rat
Alexis Bailey1, Vadim Yuferov, Jacob Bendor
1Laboratory of the Biology of Addictive Diseases, The Rockefeller University, New York, NY 10021, USA. baileya@rockefeller.edu
Abstract:
An increase in preprodynorphin (ppdyn) mRNA was detected in the caudate putamen of chronically cocaine-treated and 3-h withdrawn rats. An increase in mu-opioid receptor (MOP) mRNA levels was observed in the frontal cortex of 3-h withdrawn rats. Naloxone had no effect on the increase of MOP or ppdyn mRNA levels. The results indicate that the opioid system is altered during early withdrawal from chronic cocaine administration.
Insights
Chronic cocaine use alters the brain
Area of Science:
- Neuroscience
- Pharmacology
- Molecular Biology
Background:
- Chronic cocaine administration leads to neuroadaptations.
- Opioid system involvement in cocaine addiction is under investigation.
Purpose of the Study:
- To investigate changes in opioid system gene expression during early withdrawal from chronic cocaine.
- To determine the role of mu-opioid receptors (MOP) and preprodynorphin (ppdyn) mRNA.
Main Methods:
- Quantitative real-time PCR to measure mRNA levels.
- Analysis of caudate putamen and frontal cortex in rat models.
- Administration of naloxone to assess receptor involvement.
Main Results:
- Increased ppdyn mRNA in caudate putamen of cocaine-treated and withdrawn rats.
- Increased MOP mRNA in the frontal cortex of withdrawn rats.
- Naloxone did not affect MOP or ppdyn mRNA levels.
Conclusions:
- Early withdrawal from chronic cocaine alters opioid system gene expression.
- The opioid system undergoes significant changes during early cocaine withdrawal.
