Glucocorticoids reset circadian clock in choroid plexus via period genes

The epithelial cells of choroid plexus (CP) in brain ventricles produce cerebrospinal fluid and act as the blood-cerebrospinal barrier. In this study, we confirmed that CP 4th ventricle is composed cellular oscillators all harbor glucocorticoid receptors are mutually synchronized to a robust clock gene expression rhythm detectable at tissue level vivo vitro . Animals lacking glucocorticoids (GCs) due surgical removal adrenal glands had Per1 , Per2 Nr1d1 Bmal1 rhythmicity their significantly dampened, whereas subjecting them daily bouts synthetic GC analog, dexamethasone (DEX), reinforced those rhythms. We verified these effects using an model organotypic explants; depending on time its application, DEX increased amplitude efficiently reset phase clock. results first description PRC for non-neuronal brain, demonstrating shares some properties with clocks elsewhere body. Finally, found exhibited multiple synergic clock, including acute activation change PER2 protein turnover rate. DEX-induced shifts were partially mediated via PKA-ERK1/2 pathway. provide evidence strengthens entrains helping thus fine-tune environment according day.