| dc.description | The development of cochlear ilmplants for the treatment of patients with profound hearing loss has
advanced considerably in the last few decades, particularly in the field of speech comprehension. However,
attempts to provide not only sound decoding but also spatial hearing are limited by our understanding of
circuit adaptations in the absence of auditory input. Here we investigate the lateral superior olive (LSO),
a nucleus involved in interaural level difference (ILD) processing in the auditory brainstem using a mouse
model of congenital deafness (the dn/dn mouse). An electrophysiological investigation of principal
neurons of the LSO from the dn/dn mouse reveals a higher than normal proportion of single spiking (SS)
neurons, and an increase in the hyperpolarisation-activated Ih current. However, inhibitory glycinergic
input to the LSO appears to develop normally both pre and postsynaptically in dn/dn mice despite the
absence of auditory nerve activity. In combination with previous electrophysiological findings from the dn/
dn mouse, we also compile a simple Hodgkin and Huxley circuit model in order to investigate possible
computational deficits in ILD processing resulting from congenital hearing loss. We find that the
predominance of SS neurons in the dn/dn LSO may compensate for upstream modifications and help to
maintain a functioning ILD circuit in the dn/dn mouse. This could have clinical repercussions on the
development of stimulation paradigms for spatial hearing with cochlear implants. | |
