Deafness Research UK researchers publish in Nature Neuroscience.
Walter Marcotti and Stuart Johnson of the University of Sheffield together with colleagues from University of Sussex and from Italy and Germany, published their paper entitled 'Position-dependent patterning of spontaneous action potentials in immature cochlear inner hair cells' last month. The researchers investigated whether sensory cells in the developing ear of mammals are able to generate an intrinsic signal that could be used before the onset of hearing to form the correct connections at the right time and place to end up with our sensitive and complex hearing system. They found that inner hair cells, the tiny sensory cells in the cochlea (the mammalian auditory organ) that detect sound and transmit to the brain, show different electrical activity depending on where they are positioned along the sensory organ. The researchers also identified some of the chemicals released by nearby cells that are responsible for these differences. This early process that happens before we can hear is critical to enable us to perceive sound properly once the ear is fully developed. The knowledge gained in this study will help us to understand what can go wrong in this process and lead to hearing loss and how to better treat these conditions. Dr Marcotti and Dr Johnson commented 'The functional development of the sensory hair cells of the cochlea is thought to be guided by electrical activity that occurs spontaneously in these cells during immature stages before the onset of hearing. We found that this activity varies along the auditory sensory organ, which is likely to instruct the formation of the highly ordered auditory system at a time when sound is not yet perceived. By revealing the main determinants of normal auditory development, we hope that the information gathered could bring us closer to improving methods aimed at repairing hearing loss due to damage or genetic defects. Deafness Research UK has funded two equipment grants for Walter Marcotti's laboratory that have been critical in allowing the researchers to complete this project. The research was funded in addition by research grants from the Wellcome Trust, MRC, Royal Society and RNID and is an excellent example of how important it is for researchers to have access to funds from many sources to complete these complex projects.