1 Department of Neurology, Clinical Division of Nanlou, Chinese PLA General Hospital, Beijing100853, China 
2 Hefei National Laboratory for Physical Sciences at Microscale and Department of Neurobiology and Biophysics, Life Science School, University of Science and Technology of China, Hefei 230027, China 
3 Netherlands Institute for Neuroscience, an Institute of the Royal Netherlands Academy of Arts and Science, Amsterdam 1105BA, the Netherlands

Abstract 

Objective
Corticotropin-releasing hormone (CRH) plays an important role in neuroendocrine, autonomic and behavioral responses to stressors. In the present study, the effect of chronic unpredictable mild stress (CUMS) on CRH neurons was investigated in rat brain.
Methods
The rats were exposed to one of the stressors each day for 21 d. Immunostaining was performed to detect the CRH-positive neurons in the paraventricular nucleus (PVN) of the hypothalamus and in amygdala.
Results
After the stress protocol, the animals showed a reduction in body weight gain as well as reduced sucrose preference and locomotor activity. Interestingly, the CRH neurons in both PVN and central nucleus of the amygdala (CeA) were stimulated by CUMS. The densities of CRH-containing neurons in both PVN and CeA were significantly higher than those in control group.
Conclusion
The CRH systems in PVN and CeA may both contribute to depression-like behaviors during CUMS.

Keywords

chronic unpredictable mild stress; hypothalamo-pituitary-adrenal axis; corticotropin-releasing hormone; amygdala; paraventricular nucleus

[SpringerLink]