Dr Stuart Johnson
Royal Society University Research Fellow
Brief career history
Signalling characteristics of cochlear hair cells.
Auditory neuroscience, Sensory coding, Synaptic transmission
Mammalian cochlear inner hair cells (IHCs) are the primary sensory cells of the auditory pathway. Their job is to convert sound vibrations into an electrical signal that can be interpreted by the brain. As such, it is vital that the information encoded by IHCs is accurately preserved at this initial stage. One of the major causes of deafness/hearing loss is associated with IHCs losing their ability to function normally.
The aim of my research is to find out how IHCs are able to accurately encode sounds over a wide frequency and intensity range and how the information is processed on its way to the brain. Knowledge of how the ear processes sound will be informative to develop improved hearing aids, including cochlear implants. An additional aspect of my research applies directly to define how stem cells are able to replace damaged nerve fibres in order to restore hearing (in collaboration with Prof Marcelo Rivolta).
In order to achieve this I will study IHCs in the isolated cochlea using a combination of electrophysiological, cell imaging and molecular biological techniques.
Undergraduate and postgraduate taught modules
- The coupling between Ca2+ channels and the exocytotic Ca2+ sensor at hair cell ribbon synapses varies tonotopically along the mature cochlea.. Journal of Neuroscience, 37(9), 2471-2484. View this article in WRRO
- Connexin-Mediated Signaling in Nonsensory Cells Is Crucial for the Development of Sensory Inner Hair Cells in the Mouse Cochlea.. J Neurosci, 37(2), 258-268. View this article in WRRO
- Calcium entry into stereocilia drives adaptation of the mechanoelectrical transducer current of mammalian cochlear hair cells. Proceedings of the National Academy of Sciences, 111(41), 14918-14923.
- Progressive hearing loss and gradual deterioration of sensory hair bundles in the ears of mice lacking the actin-binding protein Eps8L2.. Proc Natl Acad Sci U S A, 110(34), 13898-13903.
- Presynaptic maturation in auditory hair cells requires a critical period of sensory-independent spiking activity.. Proc Natl Acad Sci U S A, 110(21), 8720-8725.
- Restoration of auditory evoked responses by human ES-cell-derived otic progenitors.. Nature, 490(7419), 278-282. View this article in WRRO
- The resting transducer current drives spontaneous activity in prehearing mammalian cochlear inner hair cells.. J Neurosci, 32(31), 10479-10483.
- Prestin-driven cochlear amplification is not limited by the outer hair cell membrane time constant.. Neuron, 70(6), 1143-1154.
- Position-dependent patterning of spontaneous action potentials in immature cochlear inner hair cells.. Nature Neuroscience, 14(6), 711-717. View this article in WRRO
- Synaptotagmin IV determines the linear Ca2+ dependence of vesicle fusion at auditory ribbon synapses.. Nat Neurosci, 13(1), 45-52. View this article in WRRO
- Membrane properties specialize mammalian inner hair cells for frequency or intensity encoding. eLife, 4. View this article in WRRO