Short ride in a fast sense: hearing from hair cells to cortex
Short ride in a fast sense: hearing from hair cells to cortex
Theme: Sensory and motor systems
Monday 24th April, 15:30 – 17:10
Supported by Sussex Neuroscience
Hearing is the fastest sense, some three orders of magnitude faster than vision. For example, to pinpoint where a sound comes from your brain can perceive a time difference of 10 microseconds between the two ears. In this symposium we follow the processing of sound from the mechanosensory hair cells in the inner ear, through the brainstem, to the auditory cortex. The mechano-electrical transducer channels (MET) at the tops of the auditory hair cells in the cochlea convert sounds such as speech and music into rapidly varying electrical currents, the first stage of sound processing. The MET channel properties vary with the position of the hair cells along the cochlea, having a larger conductance and pore diameter in hair cells that process high-frequency sounds. The calcium dynamics of the hair cells help determine the voltage responses of the hair cells to the MET currents, setting a limit the speed of auditory processing. This speed is preserved in the auditory nerve and the auditory brainstem, where rapidly activating and deactivating potassium channels of the Kv3 family enable action potential firing rates of up to 1000 Hz, thus preserving the exquisite temporal resolution of the auditory system. The role of the auditory cortex turns out to be more complex and enigmatic, perhaps being more important for learning to localize sounds that for sound localization per se. Understanding the respective roles of the different stages of auditory processing will help with restoring hearing loss, by optimizing cochlear implants and future drug and gene editing treatments.
- Corné Kros, University of Sussex, UK: Mechano-electrical transducer channel pore properties vary with frequency position along the cochlea (co-chair)
- Snezana Levic, Brighton and Sussex Medical School, UK: The role of the calcium-sensing receptor in regulating intracellular calcium dynamics in the mammalian cochlea (co-chair)
- Victoria Ciampani, University of Leicester, UK: Kv3 channel modulation of action potentials at high frequencies in the auditory brainstem
- Andrew King, Oxford University, UK: Why do we need an auditory cortex?