A guinea pig model of hidden hearing loss: Prelude to the development of a human model

Cochlear synaptopathy, otherwise known as hidden hearing loss, has been at least partially characterized in a number of mammalian species. Although well-established generally, the disorder is incompletely understood, particularly with regard to the extent of interspecies pathology associated with the condition. Furthermore, the extent to which recovery of lost function is achieved among species thus far studied is also incompletely understood. In this context, the existence of evidence suggesting that humans experience this form of synapse pathology calls for the development of a noninvasive protocol designed to further address the question. If confirmed, where on the disorder spectrum humans are positioned takes on a heightened sense of importance. To that end, a protocol that reliably identifies the disorder in a guinea pig model is under development and will, if successful, serve as the foundation for the development of an equivalent human protocol employing the same noninvasive electrophysiological strategy. In this report, preliminary findings from an ongoing study centered on a battery of electrophysiology and immunohistochemical studies supporting model development in guinea pigs will be reviewed with the goal of identifying response outcomes with diagnostic potential. [Work supported by the Department of Defense Award No. W81XWH-19-1-0862.]