Prof Jonathan Ashmore - Lab Page
My lab has been interested for a long time in the cellular mechanisms within the cochlea.
In particular, my colleagues and I have been interested in what the population of outer hair cells do. It turns out these cells amplify the sound coming in to the ear as they behave like fast 'motor' cells. Strictly speaking, they are actuators as their energy source is external to the cell itself.
Rock around the clock Hair Cell
This movie shows a short video of an outer hair cell being stimulated electrically by a patch pipette which enters from the lower left. It was recorded one cold Saturday morning for a BBC programme called ‘Ear We Go’ and originally broadcast on 13 August 1987. I still have the holes in my equipment where they put the camera.
This is an outer hair cell microdissected from the low frequency (apical) end of the cochlea and placed on the stage of a microscope. Cells such as this survive for a couple of hours if kept in the right culture conditions. To change the cell’s potential and then make the cell change length I just played Rock-Around-the-Clock (Bill Haley’s 1954 classic) from my (then) Walkman into the input socket of the electrophysiology amplifer. The BBC producer was delighted because even then RAtC was so ancient that they did not have to pay copyright charges.
For the scientifically minded: This outer hair cell gets thinner when it gets longer and fatter when it gets shorter. Measuring up these changes indicates that the cell volume stays constant. This supports the idea that the ‘motor’ is a molecule whose job it is to change membrane area. The molecule, discovered in 2000 by Peter Dallos’ lab in the US, is called ‘prestin’.
Links
- More information about the context for the video can be can be obtained from a fine book by Schnupp, Nelkon and King
Research Units
The research at the UCL Ear Institute can be organised into three research units: