PET Imaging Reveals Brain Metabolic Changes in Adolescent Rats Following Chronic Escalating Morphine Administration
Non-medical use of prescription opioids, especially among adolescents, has been substantially increased in recent years. However, the neuromechanism remains largely unexplored. In the present study, we aimed to investigate the brain metabolic changes in adolescent rats following chronic escalating morphine administration using positron emission tomography (PET).
2-Deoxy-2-[18F]Fluoro-d-glucose ([18F]FDG) microPET imaging was performed, and statistical parametric mapping (SPM) was used for image analysis. Glucose transporter 3 (Glut-3), dopamine D2 receptor (D2R), and Mμ-opioid receptor (μ-OR) were used for immunostaining analysis.
Cerebral glucose metabolism was increased in the corpus callosum (CC) and right retrosplenial dysgranular cortex (rRSD), while it was decreased in the right ventral pallidum (rVP). The expressions of Glut-3, D2R, and μ-OR were increased in CC and rRSD, while they were decreased in rVP. Furthermore, glucose metabolism and Glut-3 expression were positively correlated with the expressions of D2R or μ-OR in CC, rRSD, and rVP.
[18F]FDG microPET brain imaging study in combination with immunohistological investigation revealed that CC, rRSD, and rVP were specifically involved in opioid dependence in adolescents. Our findings provided valuable insights into the neuromechanism of adolescent addiction of prescription opioids and might have important implications for the development of prevention and intervention approaches.
Key wordsOpioid Glucose metabolism Positron emission tomography (PET) Statistical parametric mapping (SPM)
This work was partly sponsored by the National Natural Science Foundation of China (81301243,81425015), the Natural Science Foundation of Zhejiang Province (LY17H180004), the Research Fund for the Doctoral Program of Higher Education of China (20120101120031), the grants from the Health Bureau of Zhejiang Province (2014KYA095, WKJ2013-2-016), and supported by Zhejiang University K. P. Chao’s High Technology Development.
Compliance with Ethical Standards
All animal studies were approved by the Zhejiang University Ethics Committee for Animal Experiments (Protocol No. ZJU2015-069-02).
Conflict of Interest
The authors declare that they have no conflict of interest.
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