Effects of deafness and cochlear implant use on temporal response characteristics in cat primary auditory cortex.

Effects of deafness and cochlear implant use on temporal response characteristics in cat primary auditory cortex. Hear Res. 2014 Jun 14; Authors: Fallon JB, Shepherd RK, Nayagam DA, Wise AK, Heffer LF, Landry TG, Irvine DR Abstract We have previously shown that neonatal deafness of 7-13 months duration leads to loss of cochleotopy in the primary auditory cortex (AI) that can be reversed by cochlear implant use. Here we describe the effects of a similar duration of deafness and cochlear implant use on temporal processing. Specifically, we compared the temporal resolution of neurons in AI of young adult normal-hearing cats that were acutely deafened and implanted immediately prior to recording with that in three groups of neonatally deafened cats. One group of neonatally deafened cats received no chronic stimulation. The other two groups received up to 8 months of either low- or high-rate (50 or 500 pulses per second per electrode, respectively) stimulation from a clinical cochlear implant initiated at 10 weeks of age. Deafness of 7-13 months duration had no effect on the duration of post-onset response suppression, latency, latency jitter, or the stimulus repetition rate at which units responded maximally (best repetition rate), but resulted in a statistically significant reduction in the ability of units to respond to every stimulus in a train (maximum following rate). None of the temporal response characteristics of the low-rate gro...
Source: Hearing Research - Category: Audiology Authors: Tags: Hear Res Source Type: research