The biology of hearing and hearing loss: New insights from naked mole-rats into mechanisms and adaptive responses

Abstract

Understanding the biology of hearing and hearing loss requires not only examination of the existing structure and function of the auditory system but also consideration of its evolutionary legacy. In this context, research in my group, in collaboration with others, utilizes a comparative approach to investigate hearing and hearing loss in various rodent models, including Naked mole-rats—a highly vocal, eusocial, subterranean species exhibiting surprisingly poor hearing for reasons that long remained elusive. Our findings reveal that the comparatively poor hearing in Naked mole-rats results from a combination of factors, including the absence of cochlear amplification, disrupted hair bundles, and hair bundle proteins bearing deafness-associated amino acid substitutions. Intriguingly, evidence of positive selection in some bundle proteins suggests that altered hearing in Naked mole-rats may be an adaptive response to their subterranean and eusocial lifestyles. More recent work investigates the comparative organization of central auditory structures in Naked mole-rats to identify the mechanisms of central compensation that support auditory-vocal communication in this species despite their poor peripheral hearing. Ultimately, the Naked mole-rats serve as a naturally occurring disease model to investigate hearing loss and gain valuable insights into mechanistic approaches to treat hearing loss.