Understanding deafness: the role of auditory nerve mapping
A key step in hearing development involves creating synaptic connections between the auditory nerve and sensory cells of the inner ear, yet how this happens is not fully understood. Further knowledge is needed to identify causes of hereditary hearing loss and eventually lead to effective treatments.
IRP researchers led by Matthew Kelley, Ph.D., demonstrated that expression of Pou3f4—a protein that helps transcribe DNA into RNA—interferes with auditory nerve axon growth by forcing the axons to grow along specific tracks toward inner ear sensory cells.
The finding helps explain why mutations in the Pou3f4 gene cause hearing loss. It may also lead to improvements in the function of cochlear implants, which must connect with the auditory nerve to alleviate deafness.
Coate TM, Raft S, Zhao X, Ryan AK, Crenshaw EB 3rd, Kelley MW. (2012). Otic mesenchyme cells regulate spiral ganglion axon fasciculation through a Pou3f4/EphA4 signaling pathway. Neuron. 73(1), 49-63.