Prof. Daibhid O Maoileidigh on Making sense of the sensory hearing cells

How do we make sense of the auditory periphery? It's quite magical. The fastest moving cells in the body transduce nanometers of motion into electrical stimuli that our brain can turn into speech or music. Did I mention the feedback that lets us here over many, many orders of magnitude? To make matters more interesting it’s a dynamic system with plenty of feedback, ensuring that there are many problems to solve. And all of our auditory experiences start here. How does it work?

Who: Dáibhid Ó Maoiléidigh, Stanford Otolaryngology
What: Making Sense of the Sensory Hearing Cells
When: Friday May 26th at 10:30AM
Where: CCRMA Seminar Room (Top Floor at The Knoll)
Why It all starts at the cochlea and hair cells

It’s been a while since we’ve talked about cochlear mechanics and hair cells. I’m looking forward to an update on this part of our world. I hope you will enjoy.

Come to the CCRMA Hearing Seminar and we’ll talk about the start of the auditory system.


Making sense of the sensory hair cells.
Our hearing relies on sensory hair cells within our ears to convert vibrations caused by sound into electrical signals, which are transmitted to our brain. Each hair cell uses a micron-scale sensor, its hair bundle, to perform this conversion, called mechanoelectrical transduction. Hair bundles accomplish mechanoelectrical transduction at frequencies far higher than most other biological processes, are sensitive to vibrations smaller than the size of a hydrogen atom, and nonlinearly distort and compress the sound signal. I will discuss how the properties of a hair bundle ensure its remarkable speed, sensitivity, and nonlinearity. There are large systematic differences in bundle structure between different types of bundles and between bundles in different locations within our hearing organ. My lab is investigating how these differences regulate the roles of different types of hair bundles in hearing and enable us to hear wide ranges of sound frequencies and intensities.

Bio
Dáibhid Ó Maoiléidigh has a BA in Theoretical Physics and an MSc in High-Performance Computing from Trinity College Dublin. He was awarded his PhD in Physics from Rutgers University, where he studied pausing in transcription elongation using mathematical modeling. Dr. Ó Maoiléidigh began working on hearing at the Max Planck Institute for the Physics of Complex Systems. Subsequently, during his time at The Rockefeller University, he explained and predicted a host of experimental observations using mathematical models. He is currently an Assistant Professor in the Department of Otolaryngology - Head & Neck Surgery, where his lab uses mathematical models to understand hearing and balance. He has developed mathematical models to understand the ear's mechanics, synaptic dynamics, and otoacoustic emissions and uses experimental data to motivate, validate, and test these models. Dr. Ó Maoiléidigh has a particular interest in how the peripheral hearing and balance systems transform sensory input.

A bundle of mechanisms: inner-ear hair-cell mechanotransduction
D Ó Maoiléidigh, AJ Ricci
Trends in neurosciences 42 (3), 221-236

Mechanical transduction processes in the hair cell
DP Corey, D Ó Maoiléidigh, JF Ashmore
Understanding the cochlea, 75-111

Here is a good website about the hearing periphery.
http://www.cochlea.eu/en