Press release: Holy grail of the inner ear discovered

Nr. 144/2012 - 30.07.2012

Sound conversion: Neurobiologists in Göttingen discover responsible protein

(pug) When sound waves hit a sensory cell of the ear, they are converted into electrical nerve signals through specialized ion channels that open and close. Scientists at the University of Göttingen have now discovered a protein that is essential for the opening and closing of these ion channels. The protein could thus be responsible for the ability to hear. The investigations were conducted at the Department of Cellular Neurobiology within the framework of the Collaborative Research Centre “Molecular mechanisms of sensory processing”. The results were published in the prestigious journal Nature Neuroscience.

Using the fruit fly Drosophila melanogaster, which hears with its antenna, the scientists investigated how sound conversion functions in the ear. Minute feathers are located on the ion channels and transmit sound waves directly to them: the ion channels open and close when the fly’s antenna vibrates in a sound field. Conversely, the opening and closing of the channels causes the antenna to move. The scientists used the antenna movements caused by the channels to detect genetic defects in their function. In the process, they came upon a protein whose absence prevented the channels from opening and closing. The channel functioned again after reintroducing the protein, and only part of the channels functioned when the protein levels were reduced.

“The initial results of our study show that the loss of this protein specifically severs the feather channel complex in hearing cells”, explains Thomas Effertz, lead author of the study. “The molecular identification of this complex is considered to be the holy grail of hearing research, and we've discovered it in the ear of a fly.” The protein is called TRPN1 or NompC and can be found in the hearing cells of insects, flies and frogs. The scientists suspect that it forms both the feather and the corresponding ion channel. In order to test this theory in further studies, they want to modify the TRPN1 ion channel feather using genetic tricks, for example, to make it stiffer or softer.

Original publication: Thomas Effertz et al. Direct gating and mechanical integrity of Drosophila auditory transducers require TRPN1. Nature Neuroscience (2012). Doi: 10.1038/nn.3175.

Contact:
Prof. Dr. Martin Göpfert
Georg-August-Universität Göttingen
Faculty of Biology – Department of Cellular Neurobiology
Julia-Lermontowa-Weg 3, 37077 Göttingen
Phone +49 551 39-177955
Email: mgoepfe@gwdg.de
Internet: www.uni-goettingen.de/de/114662.html