Related Experiment Video
Updated: Aug 2, 2026
08:29
Biomarkers in an Animal Model for Revealing Neural, Hematologic, and Behavioral Correlates of PTSD
Published on: October 10, 2012
Discrimination between changes in glucocorticoid receptor expression and activation in rat brain using western blot
R L Spencer1, B A Kalman, C S Cotter
1Department of Psychology, Campus Box 345, University of Colorado, Boulder, CO 80309, USA. spencer@psych.colorado.edu
Brain Research
|June 16, 2000
Summary
Western blot analysis reveals that acute corticosterone treatment causes glucocorticoid receptor (GR) redistribution to the nucleus, not downregulation. Long-term changes in adrenalectomy or corticosterone alter GR protein expression in rat brains.
Area of Science:
- Neuroscience
- Molecular Biology
- Endocrinology
Background:
- Glucocorticoid receptor (GR) plays a crucial role in stress response and brain function.
- Understanding the autoregulation of GR expression and activation is vital for comprehending neuroendocrine regulation.
- Previous methods often conflated receptor activation with changes in protein levels.
Purpose of the Study:
- To investigate the autoregulation of glucocorticoid receptor (GR) protein expression and activation in the rat brain.
- To differentiate between GR activation and GR protein expression changes using western blot methodology.
- To establish a reliable western blot method for studying GR regulation in vivo.
Main Methods:
- Western blot analysis of cytosolic, nuclear, and whole-cell extracts from rat brain tissue.
- Comparison with receptor binding assays to validate findings.
- Utilizing adrenalectomy and corticosterone treatments to manipulate GR levels and activation.
Main Results:
- Acute corticosterone treatment led to GR redistribution from cytosol to nucleus, without altering whole-cell GR levels, indicating activation rather than downregulation.
- Long-term adrenalectomy increased cytosolic GR, while long-term corticosterone treatment decreased it, signifying changes in GR protein expression.
- Western blot of whole-cell extracts accurately reflected changes in GR protein expression, even in adrenal-intact rats.
Conclusions:
- Western blot analysis of whole-cell rat brain extracts is a valid method for studying in vivo GR protein expression regulation.
- This technique allows for the measurement of GR protein expression in adrenal-intact animals, overcoming limitations of receptor binding assays.
- The findings support the use of cytosolic receptor binding assays for estimating relative GR activation when appropriate controls are used.
