Glucocorticoid hormones are released during the active phase of the circadian cycle and in response to stress. Stress-induced high levels of glucocorticoids have been shown to increase the memory of stress-associated events and to contribute to the development of stressrelated pathologies (depression, anxiety, drug abuse…). This study provides a complete molecular pathway (GR/Egr-1/MAPK/Synapsin-Ia-Ib) through which stress and glucocorticoids enhance the memory of stressrelated events. The study involved total protein extractions both from mice hippocampi and PC12 cells using Precellys®24homogenizer .
 Revest et al. 2010. The enhancement ofstress-related memory by glucocorticoidsdepends on synapsin-Ia/Ib. Molecular Psychiatry,n° 4 (April) doi:10.1038/mp.2010.40.
The figure below shows an example of total protein extraction from PC12 cells using Precellys®24. Total extracts were analyzed by western blot. The corresponding X-ray films were quantified by densitometry. Those results allowed to better understand the action of corticosterone in the molecular cascade mediating the enhancement of stress-related memories.