Otolaryngology--head and neck surgery : official journal of American Academy of Otolaryngology-Head and Neck Surgery
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Otolaryngol Head Neck Surg · Mar 1991
Protective effect of electrical stimulation in the deafened guinea pig cochlea.
The effect of chronic intrascalar electrical stimulation on the spiral ganglion cell survival of the ototoxically deafened guinea pig was investigated. Immediately after ototoxic drug administration, unilateral sinusoidal (1 kHz) charge-balanced electrical stimulation on a 50% duty cycle was administered for 2 hours per day, 5 days per week, at intensities from 0 (control) to 400 microAmp via an implanted scala tympani electrode. The relationship of electrically evoked middle latency response (EMLR) to stimulation protocol and cell survival was studied. ⋯ Moreover, the slope of the amplitude input/output (I/O) function of the EMLR was found to be dependent on stimulating current level. The effect of stimulation on induced survival may be dependent on a number of mechanisms, including metabolic effects of direct activation of "deafferented" spiral ganglion cells. These data support the suggestion that implantation may provide optimal benefits when performed shortly after deafness.