1994 Fiscal Year Final Research Report Summary
Auditory Plasticity in Cochlear Implant Animal Model
| Project/Area Number |
05671428
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
Otorhinolaryngology
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| Research Institution | OSAKA UNIVERSITY |
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Principal Investigator |
KUBO Takeshi MEDICAL SCHOOL,OTOLARYNGOLOGY,PROFESSOR, 医学部, 教授 (30107031)
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| Co-Investigator(Kenkyū-buntansha) |
DOI Katsumi MEDICAL SCHOOL,OTOLARYNGOLOGY,ASSOCIATE PROFESSOR, 医学部, 講師 (40243224)
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| Project Period (FY) |
1993 – 1994
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| Keywords | COCHLEAR IMPLANT / ANIMAL MODEL / AUDITION / PLASTICITY / FOS / NEUROTRANSMITTER / ELECTRIC STIMUTALTION |
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| Research Abstract |
It was not known that each Cochlear Implant (Cl) patients can obtain how much speech discrimination ability prior to the operation. This study aimed to find the useful method in order to predict speech discrimination ability (auditory plasticity) in using Cl animal model and also with the patients.
I.Auditory plasticity in Cl animal model : The electrodes were inserted in the cochlea of neonatally deafended rats (Cl animal model). Electricaly driven auditory brainstem response (EABR) was compared between Cl model and control rats. The threshold of EABR showed no difference, but the ampltitude growth curve relative to the stimulus intensity showed significant difference ; the steepness was smaller in animal model. This indicated that the number of auditory nerve fibers evoked by the electric stimulation was smaller in deafended animal than the controls. As the steepness of amplitude growth curve reflected the extent of surviving auditory nerve, it became a good indicator for post-operative speech discrimination ability. The brainstem was examined for the appearance of Fos protein following the electric stimulation in the cochlea. As the dorsal conchlear nucleus contained large number of Fos positive neurons, this region was thought to be one of the important site for electrically driven auditory sensation.
II.Auditory plasticity in Cl patients : Speech discrimination scores and the electrophysiological parameters were studied for over a year in Cl patients. The results revealed positive change in each parameters. Thus, auditory plasticity was also proved in Cl patients.
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