Director: Robert V. Harrison

The Auditory Science Laboratory within the Department of Otolaryngology – Head and Neck Surgery at Sick Kids has been part of the department for almost 28 years. Over that time, the laboratory has introduced and used many novel research techniques to explore the structure and function of the auditory system. The methodologies include various brain imaging and electrophysiological techniques, our mainstay being 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. Earlier in the year, Jaina Negandhi completed her Master of Science thesis with the Department of Physiology. Jaina has been in the lab as Project Manager for a number of years, and her Masters thesis work was a very important discovery of changes to resting levels of neural activity in the auditory pathway as a result of conductive hearing loss. This work has some important implications for our understanding of the effects of long-term conductive hearing loss, for example caused by otitis media. Her work was reported at the Collegium ORL meeting and published this year in Acta Otolaryngologica.

For the past year, a Visiting Scholar from the medical school of the University of Tokyo, Japan has been working hard in the lab. “Moto” (Dr. Ujimoto Konomi) has been working on recording from neurons in the auditory brain to analyze not just the excitation, but also the inhibition of activity. We are pleased to have Moto in the lab; this re-establishes some very useful research collaborations with our colleagues in Japan. Dr. Konomi has also been working together with our paediatric otolaryngology research fellow, Dr. Sohit Kanotra on a project on age related aspects of otoacoustic emissions. Together with Adrian James we are continue to investigate the neural pathway that links the two ears. This is an important line of research that Adrian James and I started a decade ago.

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. D’Alessandro was recently chosen by the Faculty of Medicine to represent PhD trainees at a national CIHR conference in Winnipeg this summer. Well done for that honour.

In the past years, summer students have been working hard in the lab, including Brooke Allemang, Brittany Harrison, Cullen Allemang and Adrienne Harrison. These young, enthusiastic students are learning new research techniques including histology, electrophysiology and electron microscopy. I am sure that their training will offer them a glimpse into the area of basic and clinical research, which perhaps will inform their future career choices.

Other projects in the lab include analysis of vascular networks in the trachea of animal models of tracheal pathology. This work mainly done by resident Lukas Kus, supervised by Drs. Evan Propst and Vito Forte. 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.

Research funding this past year has come from CIHR as well as other contributions from the Masonic Foundation of Ontario. 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!