Cellular mechanisms of hearing

Jonathan Ashmore, FRS
Bernard Katz Professor of Biophysics UCL Ear Institute, 332 Gray's Inn Road, London WC1X 8EE
Tel: +44 (0)20 7679 8937 / 020 7679 6080 Internal: 28937
Fax: +44 (0) 20 7679 8990
Email: j.ashmore@ucl.ac.uk

Lab Members:

  • Dr Juande Navarro-Lopez
  • Chris Mullaley
  • Heather Dorricott
  • Dr Pavel Mistrik
  • Jason Mikiel-Hunter
JA1

I started out my research career as a theoretical physicist and then switched to the biophysics of vision. But I hated sitting in darkened rooms! When I was appointed a lecturer in Sussex, I met people who were interested in hearing research and those lucky people weren’t sitting in dark rooms: they were in quiet rooms instead! Luckily for me, I was there at the time when the ideas of cellular physiology were being introduced into hearing research and it was also possible to carry across principles about how the eye worked and apply them to the ear. It was some years later, when I moved to Bristol, that I was truly able to set up my own group of hearing researchers. I like the way in which trying to understand hearing brings you into contact with geneticists, physicists, nanotechnologists, audiological clinicians and surgeons and at the same time it’s all firmly rooted in mainstream physiology. UCL is a fantastic place to do that, especially in the Ear Institute where scientists of many different disciplines are actually working side by side: they even share the same benches in some cases! I’m still like my Rock Around the Clock hair cell video. I was the first person to capture a hair cell changing length in time to music on video and although most of the work I’ve done recently has nothing to do with that, it is still a really fun clip!

Research

My lab is now situated at the UCL Ear Institute - please visit my main site.

This laboratory works on the cellular mechanisms of hearing. We are particularly interested in outer hair cells of the cochlea. These cells are responsible for selectively amplifying the sound entering the ear and act by producing forces in response to a sound stimulus acting upon them. We are investigating how the motor works by using electrophysiology, imaging and other biophysical techniques. We are working on trying to understand how potassium ions flow through the cochlea and to do this we use large scale computer models to investigate the way in which individual cells within the organ of Corti integrate into creating a functional cochlea. With Chris Richards we are using 2 photon confocal microscopy to study how the fast synapse of the inner hair cell works. The laboratory is a member of UCL-LSIC and also has links with CoMPLEX, the Centre for the application of Mathematics and Physics to the Life Sciences to Experimental Biology where we are working on a DTI Beacon Project, and with the IMCB, the Interdepartmental Laboratory of Molecular and Cell Biology.

Links

Rock Around The Clock Hair Cell Video. Download it as a 5Mb MPEG movie with sound or obtain an explanation of this movie! There are growing numbers of sites devoted to hearing research. These contain a wide variety of images, data and models. Some of these are sites that provide graphics and further explanation of the topics covered in an article appearing TINS APRIL 1998 : Nobili, Mammano and Ashmore: How well do we understand the cochlea? For web sites you might like to start at the Association for Research in Otolaryngology (ARO) where the virtual library is kept up to date with many ear related web sites The sites you will find your way to include:

Full publications list with PDFs

Selected publications:

  • Muallem D, Ashmore JF (2006) An Anion Antiporter Model of Prestin, the Outer Hair Cell Motor Protein. Biophysical Journal. 90, 4035-4045. link
  • Griesinger CB, Richards CD, Ashmore JF (2005) Fast vesicle replenishment allows indefatigable signalling at the first auditory synapse. Nature. 435, 212-5. link
  • Chambard JM, Ashmore JF (2005) Regulation of the voltage-gated potassium channel KCNQ4 in the auditory pathway. Pflugers Arch – Eur J Physiol. 450, 34-44. link
  • Jonathan Ashmore (2004) Channel at the hair's end. Nature, N & V 432(7018):685-6
  • Ashmore J and Gale J E (2004) The cochlear amplifier. Curr Biol. 14(11):R403-4.
  • Griesinger CB, Richards CD, Ashmore JF. (2004) Apical endocytosis in outer hair cells of the mammalian cochlea. Eur J Neuroscience
  • J-M Chambard & J F Ashmore (2003) Sugar transport by mammalian members of the SLC26 superfamily of anion-bicarbonate exchangers. Journal of Physiology 550:667-678 link
  • C.B.Griesinger, C.D.Richards & J F Ashmore (2002) Apical endocytosis in inner hair cells imaged by two photon Imaging of FM1-43 Journal of Neuroscience 22: 3939-3952. link
  • Ashmore, JF (2002) Biophysics of the cochlea: ion channels and channelopathies. British Medical Bulletin 63:59-72
  • Jonathan Ashmore & Fabio Mammano (2001) Can you still see the cochlea for the molecules? Current Opinion in Neurobiology 11:449 link
  • Laura Lagostena, Jonathan Ashmore, Bechara Kachar & Fabio Mammano (2001) Purinergic control of intercellular communication between Hensen's cells of the guinea pig cochlea. Journal of Physiology 531:603-706. link
  • Jonathan Ashmore & Jonathan Gale (2000) The Cochlea: A Primer Current Biology 10:R325-327.
  • Jagger DJ, Griesinger CB, Rivolta MN, Holley MC, and Ashmore JF. (2000) Calcium signalling mediated by the alpha9 acetylcholine receptor in a cochlear cell line from the Immortomouse. Journal of Physiology 2000 527:49-54. link
  • Jonathan Ashmore. (2000) Hearing. In. "Sound" (Eds P.Kruth and H. Stobart) Cambridge University Press.
  • Jonathan Ashmore and Jessica de Boer (1999) Spreading the fluid word. Nature N&V 402: 476-77
  • Geleoc, G.S., ForgeA., Casalotti, S., and Ashmore, J.F. (1999) A sugar transporter as a candidate for the outer hair cell motor. Nature Neuroscience 2: 713-719. link
  • Ashmore, J. F. and Geleoc, GS (1999) Hearing in the fast lane. Current Biology 9: 572-574
  • Jagger, D.J., Holley, M.C. and Ashmore J.F. (1999) Ionic currents expressed in a cell line derived from the organ of Corti of the Immortomouse. Pflugers Arch -Eur J Physiol. 438: 8-14. link
  • Jagger, D.J., and Ashmore J.F. (1999) Regulation of ionic currents by protein kinase A and intracellular calcium in outer hair cells isolated from the guinea pig cochlea. Pflugers Arch -Eur J Physiol. 437: 409-416 link