Glucocorticoids stimulate hypothalamic dynorphin expression accounting for stress-induced impairment of GnRH secretion during preovulatory period.

•Preovulatory-like concentrations of estrogens favor glucocorticoid gene regulation.•Stress-like glucocorticoid concentrations regulate hypothalamic prodynorphin expression.•The glucocorticoid receptor binds to and transactivates prodynorphin promoter.