Mouse Auditory Testing Core Facility

National Institute On Deafness And Other Communication Disorders

Investigators

Linked publications & trials

Abstract

The Mouse Auditory Testing (MAT) Core assists investigators at the National Institute on Deafness and Other Communication Disorders (NIDCD) and their collaborators with tests of auditory and vestibular function in mice. Two physiological measures of auditory function are employed in the MAT Core: the auditory brainstem response (ABR) and distortion-product otoacoustic emissions (DPOAEs). The ABR is an evoked potential that can be used to estimate hearing thresholds. DPOAEs are soft sounds that are recorded in the ear canal using a small microphone. DPOAEs can be used to screen for hearing loss and to evaluate inner ear function; specifically, the presence of DPOAEs indicates normal function of outer hair cells in the inner ear. Vestibular sensory evoked potentials (VsEPs) are measured to assess vestibular function. VsEPs are generated by the vestibular nervous system in response to linear movements of the head and provide information about function of the otolith organs (utricle and saccule). The Core assists with noise exposure protocols as needed. Hands-on training and observation in the Core were suspended from October 2020-June 2021 due to the COVID-19 pandemic. Dr. Fitzgerald conducted hands-on training in auditory function testing with four NIDCD investigators in July-September 2021. Eleven NIDCD investigators conducted auditory function testing independently with support from the MAT Core. Normative and experimental VsEP data collection by Dr. Talah Wafa (Post-Doctoral Fellow) continued this year. Dr. Fitzgerald began a collaboration with John Kakareka (Electronics Engineer, Signal Processing and Instrumentation Section (SPIS) of the Computation Bioscience and Engineering Lab (CBEL) in the Center for Information Technology (CIT)) to develop a custom probe for DPOAE measurements. Dr. Fitzgerald began setup of a third auditory test suite in August-September 2021. Dr. Fitzgerald and Dr. Wafa collaborated on and/or supported projects conducted in eight NIDCD labs. Dr. Fitzgerald collaborated on two projects by labs in the National Institute on Neurological Disorders and Stroke (NINDS). Dr. Wafa collaborated on one of these projects. Dr. Fitzgerald was a co-author on three manuscripts published this past year. Dr. Wafa was a co-author on one of the manuscripts. Information on collaborations with specific laboratories is listed below. Inner Ear Gene Therapy Program (PI: Wade Chien, M.D.) Dr. Fitzgerald provided support to Kevin Isgrig (Biologist), Yasuko Ishibashi (Post-Doctoral Fellow), Jinwoong Choi, and Jianliang Zhu (Biologist) for multiple projects investigating the use of gene therapy to remediate hearing loss. Drs. Fitzgerald and Wafa collaborated with Kevin Isgrig, Mhamed Grati (Staff Scientist), and Dr. Chien on a project investigating the use of gene therapy to remediate vestibular dysfunction in mutant mice. Section on Sensory Cell Biology (PI: Lisa Cunningham, Ph.D.) Dr. Fitzgerald trained Drs. Cathy Sung and John Lee (Post-Doctoral Fellows) in auditory test procedures. Dr. Fitzgerald provided support to Dr. Sung, Dr. Lee, and Dr. Katharine Fernandez (Staff Scientist) for projects investigating prevention of hearing loss caused by ototoxic drugs. Laboratory of Molecular Genetics (PI: Thomas Friedman, Ph.D.) Dr. Fitzgerald collaborated on multiple projects examining auditory function in various mutant mouse strains, including projects with Dr. Inna Belyantseva (Staff Scientist), Rabia Faridi (Post-Doctoral Visiting Fellow), Dr. Rizwan Yousaf (Post-Doctoral Visiting Fellow), Elizabeth Wilson Bernhard (Biologist), and a collaboration between the Chien lab and Dr. Belyantseva. Section on Molecular Biology and Genetics (PI: Isabelle Roux, Ph.D.) Dr. Fitzgerald began training Kerstin Valente (Biologist) in auditory testing and supported independent auditory testing by Kelly Hedger (Biologist). Drs. Fitzgerald and Wafa collaborated with Ms. Valente, Ms. Hedger, and Dr. Roux on projects that included auditory and vestibular function testing in several mouse lines segregating alleles of Slc26a4 with missense mutations identified in patients with hearing loss and enlarged vestibular aqueduct. Auditory Development and Restoration Program (PI: Michael Hoa, M.D.) Dr. Fitzgerald supported auditory testing by Rafal Olszewski (Biologist) on a mouse model of fluctuating hearing loss. Dr. Fitzgerald assisted with preparation of one accepted manuscript. Laboratory of Cochlear Development (PI: Matthew Kelley, Ph.D.) Dr. Fitzgerald supported auditory function testing of mutant mice by Dr. Braulio Peguero (Post-doctoral Fellow). Drs. Fitzgerald and Wafa assisted with preparation and revision of one published manuscript from a collaboration with Dr. Beatrice Mao (Post-doctoral Fellow), Tara Balasubrumanian (Post-bac IRTA), Dr. Kelley, and members of the the Blast-Induced Neurotrauma Branch at the Walter Reed Army Institute of Research on a project investigating the effects of blast trauma on auditory and vestibular function in mice. Molecular and Epigenetic Mechanisms of Hereditary Hearing Loss (PI: Robert Morell, Ph.D.) Dr. Fitzgerald supported auditory testing of mutant mice by Kelly Hedger (Biologist). Section on Sensory Cell Regeneration and Development (PI: Doris Wu, Ph.D.) Drs. Wafa and Fitzgerald collaborated with Dr. Youngrae Ji (Post-Doctoral Visiting Fellow), Austin Huang (Post-Bac IRTA), and Dr. Wu on projects examining auditory and vestibular function in conditional knockout mice. Dr. Fitzgerald assisted with noise exposures for a pilot project by Dr. Ji. Molecular Physiology and Biophysics Section, NINDS (PI: Kenton Swartz, Ph.D.) Dr. Fitzgerald collaborated with Dr. Angela Ballesteros Morcillo (Post-Doctoral Fellow) and Dr. Swartz on one published manuscript for a project on hearing loss in mT/mG transgenic mice. Spatial Navigation and Memory Unit, NINDS (PI: Yi Gu, Ph.D.) Dr. Fitzgerald collaborated with Duc Nguyen (Post-Bac IRTA) and Dr. Gu on a project using in-vivo calcium imaging of the entorhinal cortex during spatial navigation. The Core performed auditory testing to ensure the mice could hear auditory cues that are part of the experimental task.