How the Brain Connects with the Ear: Corticofugal Oscillatory Modulation of Cochlear Responses

Paul H. Delano from ENT, Universidad de Chile, Santiago, Chile, has been invited by Prof. Marlies Knipper in the frame of “Highlight Seminar Series” of the Centre for Neurosensory Systems. Dr Delano will talk on

Thursday, 7 November 2024 – 15:00-16:30 CET, HNO-Hörsaal
 

Talk Abstract:

Evidence from vertebrates and invertebrates shows that oscillatory mechanisms in the nervous system underlie perception and cognition. Changes in amplitude and phase of brain oscillations within specific frequency bands are thought to facilitate attentional selection, enabling synchronization across various brain regions, whether locally or on a larger scale. However, the extent to which cortical oscillations influence cochlear responses at the receptor level during selective attention to visual stimuli remains unclear. In our recent studies involving humans (both control and tinnitus groups), we developed a new method to examine amplitude changes in the envelope of distortion product otoacoustic emissions (DPOAE) within the frequency range of 1 to 50 Hz, simultaneously measuring electroencephalographic (EEG) activity during a task that alternates between visual and auditory attention. Our results indicate that the switch in attention between visual and auditory modalities modulates both the amplitude and the temporal order of brain and inner ear infrasonic oscillations. Additionally, we found that oscillatory activity was preserved in tinnitus patients. Together, these findings extend the role of oscillatory activity in the nervous system during cognition to the receptor level.

Delano CV:

Paul Delano is an Otolaryngology and Neuroscience Professor in both Departments at the Universidad de Chile. He received his MD (2000) and PhD training (2006) in Neuroscience at the University of Chile. He pursued training as an Otolaryngologist in the residency program of the Clinical Hospital of the University of Chile (2010). In 2010, he joined the Neuroscience and Otolaryngology Departments as scientist and otolaryngologist, leading the Laboratory of Neurobiology of Audition from the Faculty of Medicine of the University of Chile. At the University of Chile, he has been studying the physiological mechanisms of corticofugal projections from the brain to the inner ear, focusing on the cognitive role of the auditory efferent system, using animal models, but also performing experiments in humans. He has also studied clinical otolaryngology, especially the relation between hearing loss, tinnitus and cognition. He was the Director of the Otolaryngology Department in the University of Chile (2019-2022). Nowadays, he is the Academic Director of the Clinical Hospital of the University of Chile in Santiago.
https://orcid.org/0000-0003-2588-4757 

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