Glucocorticoid receptors modulate auditory sensitivity to acoustic trauma

Glucocorticoids are widely used to treat different hearing disorders yet the exact mechanisms of glucocorticoid action on the inner ear are not known. The inner ear of both humans and experimental animals demonstrate an abundance of glucocorticoid receptors (GRs) in both neuronal and non-neuronal tissues. In this review, we discuss how activation of the hypothalamic-pituitary-adrenal axis can directly modulate hearing sensitivity. Recent findings indicate that several factors define the responsiveness of the peripheral auditory system to glucocorticoids including the concentration of agonist, availability of the GR, and the activation of GR and NF-KB. These findings will further our understanding of individual glucocorticoid responsiveness to steroid treatment, and will help improve the development of pharmaceuticals to selectively target GR in the inner ear for individuals with increased sensitivity to acoustic trauma. (C) 2006 Elsevier B.V. All rights reserved.