Fetal central auditory system metabolic response to cochlear implant stimulation.
OBJECTIVE
The purpose of this study was to examine the effects of profound auditory deprivation and its treatment by cochlear implantation and stimulation on the metabolic activity of the central auditory system in fetal sheep.


METHODS
Six ovine fetuses at 85% to 90% gestation were bilaterally deafened by kanamycin perfusion and unilaterally implanted with cochlear electrode arrays. Half of the implanted animals were stimulated with an extrauterine sound processor, and half were not. Four animals served as hearing controls. One week postoperatively, central nervous system metabolic activity was evaluated in ambient laboratory noise by quantitative autoradiography using (14)C-deoxyglucose.


RESULTS
Kanamycin perfusion deafened all treated animals as verified by auditory brainstem response and scanning electron microscopy. Glucose utilization in the inferior colliculus was markedly lower in deafened and unstimulated animals relative to hearing controls. Glucose utilization in implanted-stimulated animals was similar to normal controls.


CONCLUSIONS
Changes in central auditory system metabolic activity associated with congenital deafness may be minimized by prompt auditory habilitation.
Antonelli
Patrick J
PJ
Department of Otolaryngology, University of Florida, Gainesville 32610-0264, USA. antonpj@ent.ufl.edu
Gerhardt
Kenneth J
KJ
Abrams
Robert M
RM
Huang
Xinyan
X
D000818:Animals; D000900:Anti-Bacterial Agents; D001304:Auditory Diseases, Central / Q000139:chemically induced / Q000151:congenital / Q000175:diagnosis / Q000378:metabolism* / Q000601:surgery*; D001345:Autoradiography; D001923:Brain Chemistry; D002250:Carbon Radioisotopes / Q000378:metabolism; D019929:Cochlear Implantation; D004195:Disease Models, Animal; D016057:Evoked Potentials, Auditory, Brain Stem; D005315:Fetal Diseases / Q000175:diagnosis / Q000378:metabolism* / Q000601:surgery*; D005865:Gestational Age; D006801:Humans; D007231:Infant, Newborn; D007612:Kanamycin; D008855:Microscopy, Electron, Scanning; D015997:Neonatal Screening; D011295:Prenatal Care / Q000379:methods*; D012756:Sheep
D000900:Anti-Bacterial Agents; D002250:Carbon Radioisotopes; D007612:Kanamycin