Cochlear implants function by electrically stimulating auditory neurons in the absence of hair cells, to enable hearing in severe to profoundly deaf individuals. The efficacy of this device therefore depends on a critical number of surviving auditory neurons. Stem cell transplantation therapy is emerging as a potential strategy for auditory nerve rehabilitation, as differentiated stem cells may provide a source of replacement auditory neurons to the deaf cochlea. The successful engraftment of stem cells into the cochlea will require both the directed growth of new processes and the formation of functional connections with existing structures, and we are investigating these questions using a number of in vitro and in vivo experimental models.
We are particularly interested in the role of electrical stimulation (delivered via a fully implantable stimulator or using multielectrode arrays) in directing neurite outgrowth and improving functional connectivity in the auditory brainstem. Available projects fall into two general categories and can be tailored to suit individual backgrounds/strengths:
In vitro: investigating the role of multielectrode arrays in directing growth and enhancing functional activity of stem cell-derived neurons
In vivo: investigating the combined effect of stem cell transplantation and electrical stimulation on improving hearing after deafness
(Image from Nayagam et al., Stem Cells and Development, 2013) These projects are most suitable for PhD candidates.