Restraint stress modulates glucocorticoid receptors and nuclear factor kappa B in the cochlea

The regulation of glucocorticoid receptors and nuclear factor kappa B was evaluated in the spiral ganglion neurons after 4 h of restraint stress in the mouse cochlea. Immediately after restraint stress, glucocorticoid receptor protein expression was not altered in spiral ganglion neurons even though both the plasma corticosterone levels and glucocorticoid receptor nuclear translocation increased. By 24 h after restraint stress, the protein expression of glucocorticoid receptors was decreased in spiral ganglion neurons. Pre-treatment with RU486 and metyrapone prevented nuclear translocation of glucocorticoid receptors and nuclear factor kappa B. Moreover, the synthesis of nuclear factor kappa B protein (p65) and inhibitory factor kappa B alpha decreased when RU486 and metyrapone treatment was given before restraint stress. These findings suggest that restraint stress modulates glucocorticoid receptor and nuclear factor kappa B activity in the spiral ganglion neurons, resulting in an altered response to stress.