Abstract
Aim: The focus of this project is to identify biomarkers related to circadian disturbances in major depressive disorder.
Background: A large body of clinical data from depressed individuals showed that sleep, temperature, hormones, physiological states and moodchanges are consistent with disturbances in circadian related processes. The suprachiasmatic nucleus (SCN) is well known for its function as the master clock and regulates several circadian systems by clock genes expression. In addition to central expression, peripheral clock genes have been found.
Methods: The study is based on a highly validated animal model of depression, the chronic mild stress model (CMS). Depression-like and control rats were killed by decapitation within 24 h. Trunk blood, brain and liver tissue were collected. The quantitative amount of plasma corticosterone and melatonin were measured using an ELISA and RIA kit, respectively. Identification of specific clock genes in the liver was done by using the q-PCR method. Quantification and visualization of clock genes in the brain were established by the in situ hybridization method.
Results: We studied three of the most essential clock genes, PER1, PER2 and Bmal1, and found that depression-like animals showed an abnormal circadian rhythm in the liver and in subregions of the rat brains related to depression. However, the SCN was partly protected against stress. We found an increased level of corticosteron and melatonin, in the depression-like animals as well as a shifted circadian rhythm.
Conclusion: Abnormalities in circadian rhythms, both centrally and peripherally, are related to depression-like state in the CMS model.
Research support:
This study is supported by Aarhus University and Illum fondet
Background: A large body of clinical data from depressed individuals showed that sleep, temperature, hormones, physiological states and moodchanges are consistent with disturbances in circadian related processes. The suprachiasmatic nucleus (SCN) is well known for its function as the master clock and regulates several circadian systems by clock genes expression. In addition to central expression, peripheral clock genes have been found.
Methods: The study is based on a highly validated animal model of depression, the chronic mild stress model (CMS). Depression-like and control rats were killed by decapitation within 24 h. Trunk blood, brain and liver tissue were collected. The quantitative amount of plasma corticosterone and melatonin were measured using an ELISA and RIA kit, respectively. Identification of specific clock genes in the liver was done by using the q-PCR method. Quantification and visualization of clock genes in the brain were established by the in situ hybridization method.
Results: We studied three of the most essential clock genes, PER1, PER2 and Bmal1, and found that depression-like animals showed an abnormal circadian rhythm in the liver and in subregions of the rat brains related to depression. However, the SCN was partly protected against stress. We found an increased level of corticosteron and melatonin, in the depression-like animals as well as a shifted circadian rhythm.
Conclusion: Abnormalities in circadian rhythms, both centrally and peripherally, are related to depression-like state in the CMS model.
Research support:
This study is supported by Aarhus University and Illum fondet
| Original language | English |
|---|---|
| Publication date | 1 May 2014 |
| Publication status | Published - 1 May 2014 |
| Event | Stress and behavior - Skt. Petersborg, Skt. Petersborg, Russian Federation Duration: 15 May 2014 → 19 May 2014 |
Conference
| Conference | Stress and behavior |
|---|---|
| Location | Skt. Petersborg |
| Country/Territory | Russian Federation |
| City | Skt. Petersborg |
| Period | 15/05/2014 → 19/05/2014 |