Director: Robert V. Harrison

The Auditory Science Laboratory within the Department of Otolaryngology – Head and Neck Surgery at SickKids has been part of the department for almost 30 years. Over that time, the laboratory has adopted many novel research techniques to explore the structure and function of the normal and pathological auditory system. The methodologies include various brain imaging and electrophysiological techniques, including our mainstay, the recording of single neurons from different areas of the auditory brain. We also carry out evoked potential and otoacoustic emission research in human subjects and in animal models. On the anatomical side, we continue to do electron microscopy and various histological evaluations of the inner ear, and we also probe neural pathways in the brain associated with hearing using neural tracer studies, or most recently immunolabeling for cell activity.

This past year has been very busy and productive. Jaina Negandhi has been in the lab as Project Manager for a number of years. Over the past year she has been exploring some important issues regarding hearing loss as a result of cochlear damage. For example, she has described in some detail the time course of cochlear excitotoxicity caused by massive glutamate release after inner haircell damage.

graphs showing excitotoxicity

A visiting scholar from the medical school of the University of Tokyo, Dr. Ujimoto Konomi (“Moto”) has completed important studies on the age-related aspects of otoacoustic emission suppression. The work was presented at the Collegium meeting (Rome) and published in Acta Otolaryngologica. In this work Konomi worked together with our paediatric otolaryngology research fellow, Dr. Sohit Kanotra. On further research on otoacoustic emissions Dr. Adrian James has been working on the development of a new diagnostic device involving contralateral emission suppression.

Over the past year, Lisa D’Alessandro has continued her PhD thesis work. She has been interested in patterns of neural activity in the auditory midbrain, and has been investigating whether certain sounds presented repeatedly at birth can cause a rewiring of the auditory midbrain. Mattia Carrero a Master’s trainee with IBBME, started his research work this year and has made tremendous progress investigating some important aspects of the blood supply to the cochlea. Other trainees in the past year are summer students who have been working hard in the lab, including Adrienne Harrison, Cullen Allemang and Emily Papsin. These young, enthusiastic students are learning new research techniques including histology, electrophysiology and electron microscopy.

This past year, through the funding of a CIHR team grant, we have had some very fruitful collaborations with other research teams including that of Dr. Lu-Yang Wang at SickKids and Dr. Vince Lin at Sunnybrook Health Science Centre. These collaborations have led to significant research findings. In addition to basic laboratory-based research we have active collaboration with the Cochlear Implant Research Lab, directed by Drs. Blake Papsin and Karen Gordon, and also the Centre for Voice and Laryngeal Function, directed by Dr. Paolo Campisi.

Our research productivity has been good with findings published in a range of basic science and clinical journals. The Auditory Science Laboratory has had a productive year thanks to all the hard work of our trainees and staff. Well done!