-transparent.png){kind=logo}
Intracochlear electrical stimulation via cochlear prostheses has been employed as a means of providing some hearing to deaf children. Since chronically restricted stimuli are known to have profound effects on central nervous system development, it is important to examine the effects of chronic intracochlear electrical stimulation in a neonatally deafened animal model. In this study neonatally deafened cats were implanted with a scala tympani electrode consisting of two pairs of electrodes. Chronic electrical stimulation was delivered using one electrode pair and consisted of charge-balanced biphasic pulses (200 microseconds/phase, 30 pps) at 2 dB above the electrically evoked auditory brain stem response (EABR) threshold for 4 h/day or at 6 dB 1 h/day, 5 days/week, for up to 3 months. The second electrode pair was unstimulated and served as an internal control. Following chronic stimulation, acute mapping experiments were performed in the central nucleus of the inferior colliculus (ICC) using single unit and multi-unit recording techniques and activating each electrode pair separately. In addition to these chronically stimulated animals, 2 other groups of experimental animals were studied: A normal group consisting of prior normal adult cats that were acutely implanted; and an unstimulated control group consisting of neonatally deafened adult cats that were either acutely implanted or implanted at 8-10 weeks of age but not chronically stimulated. Among the major findings of this study are: Electrical stimulation of the intracochlear bipolar electrode consistently produces activation of a reproducibly limited sector of the ICC. The location of this activated sector was found to be consistent with the known cochleotopic organization of the ICC and the intracochlear location of the stimulating electrodes. No major differences in the spatial representation of activated electrodes were found between prior normal cats and neonatally deafened unstimulated cats. The locations, shapes and widths of these spatial representations were virtually indistinguishable indicating that ICC cochleotopic organizations were equivalent in these two experimental groups. In contrast, the ICC representation of chronically stimulated electrode pairs were found to be significantly different. The average area activated by chronically stimulated electrode pairs at 6 dB above minimum threshold was approximately twice that of unstimulated deafened animals and prior normal animals; and it was larger, but not significantly so, than the average of the unstimulated electrode pair in the same experimental group.(ABSTRACT TRUNCATED AT 400 WORDS)
R L Snyder, and
S J Rebscher, and
K L Cao, and
P A Leake, and
K Kelly
November 1997,
The American journal of otology,
R L Snyder, and
S J Rebscher, and
K L Cao, and
P A Leake, and
K Kelly
January 1997,
Advances in oto-rhino-laryngology,
R L Snyder, and
S J Rebscher, and
K L Cao, and
P A Leake, and
K Kelly
July 2021,
Hearing research,
R L Snyder, and
S J Rebscher, and
K L Cao, and
P A Leake, and
K Kelly
January 1997,
Advances in oto-rhino-laryngology,
R L Snyder, and
S J Rebscher, and
K L Cao, and
P A Leake, and
K Kelly
January 1981,
The Annals of otology, rhinology & laryngology. Supplement,
R L Snyder, and
S J Rebscher, and
K L Cao, and
P A Leake, and
K Kelly
May 1998,
Clinical and experimental pharmacology & physiology,
R L Snyder, and
S J Rebscher, and
K L Cao, and
P A Leake, and
K Kelly
September 1999,
Journal of neurophysiology,
R L Snyder, and
S J Rebscher, and
K L Cao, and
P A Leake, and
K Kelly
July 2014,
Hearing research,
R L Snyder, and
S J Rebscher, and
K L Cao, and
P A Leake, and
K Kelly
January 1981,
The Annals of otology, rhinology & laryngology. Supplement,
R L Snyder, and
S J Rebscher, and
K L Cao, and
P A Leake, and
K Kelly
December 2015,
Otology & neurotology : official publication of the American Otological Society, American Neurotology Society [and] European Academy of Otology and Neurotology,
