Sensorineural hearing loss in insulin-like growth factor I-null mice: A new model of human deafness

Abstract

It has been reported that mutations in the gene encoding human insulin-like growth factor-I (IGF-I) cause syndromic hearing loss. To study the precise role of IGF-I in auditory function and to hypothesize the possible morphological and electrophysiological changes that may occur in the human inner ear, we have analysed the auditory brainstem response in a mouse model of IGF-I deficiency. We show here that homozygous Igf-1-/- mice present an all-frequency involved bilateral sensorineural hearing loss. Igf-1-/- mice also present a delayed response to acoustic stimuli; this increases along the auditory pathway, indicating a contribution of the central nervous system to the hearing loss in Igf-1-/- mice. These results support the use of the Igf-1-/- mouse as a new model for the study of human syndromic deafness. © The Authors (2006).