Dr. rer. nat. Meike Marie Rogalla 

Age-related alterations throughout the auditory system have a profound impact on hearing. Besides age-related hearing loss that compromises the inner ear and the auditory nerve, alteration within inhibitory circuits of the central nervous system have been identified. Inhibition plays a key role in shaping auditory perception. Especially for binaural processing, the integration of sound from both ears enabling directional hearing, a robust level of inhibition within the auditory brainstem is required. It is believed that this inhibition is reduced in aged individuals, which limits the intelligibility of complex sounds like speech in environments with multiple sound sources (e.g., in cocktail-party situations). Although the binaural circuitry has been identified, the effect of inhibition on binaural processing is still under debate. The aim of this project is to dissect effects of inhibition on binaural processing mechanisms by using a unique combination of behavioral testing and a virtual acoustic reality while manipulating inhibition. Light delivered via optical fiber implants will be used to silence inhibitory activity within the auditory brainstem while adult Mongolian gerbils with normal hearing engage in sound localization, a behavioral measure for binaural processing. The localization error that is due to reduced brainstem inhibition will allow for the identification of mechanisms underlying binaural processing and provide the behavioral proof for the role of inhibition in these circuits.