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Altered Expression Pattern of Clock Genes in a Rat Model of Depression
S L Christiansen1, E V Bouzinova1, J Fahrenkrug1
1Translational Neuropsychiatry Unit, Department of Clinical Medicine, Aarhus University, Denmark (Drs Christiansen, Bouzinova, and Wiborg); Department of Clinical Biochemistry, Faculty of Health Sciences, University of Copenhagen, Denmark (Dr Fahrenkrug).
The International Journal of Neuropsychopharmacology
|July 2, 2016
Summary
Chronic mild stress in rats alters diurnal expression of clock genes, particularly Per2, suggesting a link between circadian rhythm disturbances and depression. This research explores the biological mechanisms underlying this connection.
Area of Science:
- Neuroscience
- Chronobiology
- Molecular Biology
Background:
- Circadian rhythm abnormalities are implicated in major depressive disorder.
- Research is ongoing to understand the biological link between circadian rhythms and depression.
- Single-nucleotide polymorphisms in clock genes have been observed in depressive patients.
Purpose of the Study:
- To investigate if a depression-like state in rats is associated with altered diurnal expression of clock genes.
- To examine the expression patterns of Per1, Per2, and Bmal1 in a chronic mild stress (CMS) rat model of depression.
Main Methods:
- Utilized the CMS rat model to induce a depression-like state.
- Collected brain and liver tissue from control and CMS rats at 4-hour intervals over 24 hours.
- Quantified clock gene expression using in situ hybridization histochemistry in various brain regions and real-time quantitative PCR in the liver.
Main Results:
- The impact of CMS on clock gene expression was found to be selective and region-specific.
- Per1 displayed a consistent diurnal rhythm across most brain regions studied.
- Bmal1 and Per2 expression were notably affected by CMS, indicating susceptibility to the stressor.
Conclusions:
- Altered expression of clock genes, specifically Per2 and Bmal1, is likely associated with the development of a depression-like state in the CMS model.
- These findings contribute to unraveling the biological mechanisms connecting circadian rhythm disturbances and depression.
