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Fluorescence Activated Cell Sorting (FACS) and Gene Expression Analysis of Fos-expressing Neurons from Fresh and Frozen Rat Brain Tissue
Published on: August 27, 2016
Expression of c-Fos-like immunoreactivity in the brain of mice with learned helplessness
Yn-Ho Huang1, Chih-Ya Cheng, Chen-Jee Hong
1Institute of Anatomy and Cell Biology, School of Medicine, National Yang-Ming University, Shih-Pai, Taipei, 112, Taiwan, ROC. ynho@ym.edu.tw
Insights
Learned helplessness (LH) in mice, an animal model for depression, shows altered c-Fos protein expression in key brain regions. This suggests specific neural pathways involved in stress response and depressive behaviors.
Area of Science:
- Neuroscience
- Behavioral Neuroscience
- Molecular Psychiatry
Background:
- Learned helplessness (LH) is a validated animal model for human major depression.
- c-Fos protein expression indicates neuronal activation in response to stress.
- Understanding brain region involvement in LH is crucial for depression research.
Purpose of the Study:
- To investigate c-Fos expression patterns in brain regions associated with stress and depression in a mouse model of LH.
- To identify specific neural circuits implicated in the development of learned helplessness behaviors.
Main Methods:
- Utilized the learned helplessness paradigm in mice subjected to inescapable stress.
- Examined c-Fos-like immunoreactivity (FLI) across various brain regions.
- Compared FLI levels between LH mice and naive control mice.
Main Results:
- LH mice exhibited significantly lower FLI in the hippocampus dentate gyrus and lateral septal nucleus.
- LH mice displayed significantly higher FLI in the hypothalamic paraventricular nucleus compared to naive mice.
- Findings align with previous studies implicating the lateral septal nucleus and hypothalamic paraventricular nucleus in LH.
Conclusions:
- The hippocampus dentate gyrus, lateral septal nucleus, and hypothalamic paraventricular nucleus are key brain regions involved in learned helplessness behaviors.
- These findings provide a foundation for exploring the molecular mechanisms underlying depression and stress-related disorders.
- The study validates the mouse LH model for investigating neurobiological correlates of depression.
Abstract:
The learned helplessness (LH) developed after repeat inescapable stress is a well validated animal model of human major depression and is not species specific. c-Fos, the protein product of the protooncogene c-fos, is expressed in neurons under a variety of stressors and could reflect the regional neuronal activation. Using the LH paradigm in mice, we examined c-Fos expression in several brain regions related to stress response or major depression. The LH mice showed significantly lower c-Fos-like immunoreactivity (FLI) in the hippocampus dentate gyrus and the lateral septal nucleus, and higher FLI in the hypothalamic paraventricular nucleus compared with the naive mice. Our finding in the mice LH model supported previous studies in rats showing that the lateral septal nucleus and the hypothalamic paraventricular nucleus are important in LH behaviors. We further demonstrated that hippocampus dentate gyrus, a region important for learning and major depression, may also be involved in the LH behaviors. These related brain regions could provide a basis for further exploration of the molecular mechanisms underlying LH behaviors.
