HAIRSPIKE - pH control of hair cell development

In the mammalian inner ear, specialized auditory receptor cells due to their characteristic hair-like processes at the apical pole termed hair cells transform incoming acoustic signals to neural code in the auditory nerve. To faithfully fulfill this challenging task with utmost temporal precision, hair cell synaptic transmission must be finely tuned during developmental maturation. This refinement process is absolutely essential since hair cell synapses initiate the ascending auditory pathway and hence form the cellular basis of sound perception. Prior to hearing onset, pre-sensory spontaneous activity in the auditory periphery triggers hair cell synaptic release in the absence of external sound input, hence enabling correct neuronal wiring and functional maturation of the involved synaptic relay stations of the auditory pathway. While the origin of this spontaneous activity in the cochlear periphery has been an area of intense research in recent years, the molecular mechanisms underlying the fine-tuning of this process remain largely elusive to date. Hence, the international collaboration project HAIRSPIKE between the Institute of Physiology at the Medical University Innsbruck and the Institute or Neuroscience at the University of Montpellier aims to investigate the role of synaptic pH regulation on hair cell excitability. To this end, we will combine molecular biology with advanced light microscopy, modelling and electrophysiological measurements to advance our understanding of hair cell development and the functional maturation of the ascending auditory pathway.