| Project/Area Number |
08457455
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Otorhinolaryngology
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| Research Institution | Jichi Medical School |
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Principal Investigator |
KITAMURA Ken Jichi Medical School, Dept.of Otolaryngology, Prof., 医学部, 教授 (90010470)
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| Co-Investigator(Kenkyū-buntansha) |
ISHII Kosuke Jichi Medical School, Dept.of Otolaryngology, 医学部, 助教授 (30151319)
KAKOI Hiroyuki Jichi Medical School, Dept.of Otolaryngology, Lecturer, 医学部, 講師 (40201412)
石田 孝 自治医科大学, 医学部, 講師 (10151375)
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| Project Period (FY) |
1996 – 1998
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| Project Status |
Completed (Fiscal Year 1998)
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| Budget Amount *help |
¥4,000,000 (Direct Cost: ¥4,000,000)
Fiscal Year 1998: ¥1,400,000 (Direct Cost: ¥1,400,000)
Fiscal Year 1997: ¥1,200,000 (Direct Cost: ¥1,200,000)
Fiscal Year 1996: ¥1,400,000 (Direct Cost: ¥1,400,000)
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| Keywords | Mouse / Deafness / Inner ear anomaly / Gene / マウス / 遺伝子性難聴 / 行動異常 / 蝸牛変性 |
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| Research Abstract |
Pathophysiology of sensorineural hearing impairment which is acommon clinical disorder remains yet to be determined. However, some genes responsible for sensorineural hearing impairment have been cloned for the last several years and the mechanism causing hearing impairment has been started to be clarified with the advent of development of molecular genetics. We studied here pathophysiology of human sensorineural hearing loss by evaluating the mutant mouse with abnormal behavior and severe hearing loss.
Wriggle Mouse Sagami (WMS) is a spontaneous mutant strain with neuroepithelial defects. These animals are characterized by abnormal movements linked to an autosomal recessive gene. To determine the association between inner ear histology and hearing ability, we assayed these characteristics in mice homozygous and heterozygous for the mutation, as well as in wild-type animals. In homozygotes, the cochlea and saccule degenerated three months after birth. Three-month-old heterozygotes demonstrated degeneration in the cochlea, not in the saccule. No obvious auditory brainstem evoked response (ABR) was observed at any frequency in homozygotes aged one month and older. In contrast, the heterozygotes retained some hearing acuity until the age of one month, after which they became deaf.
Taken together, loss of hearing is transmitted by an autosomal dominant manner although abnormal movements are transmitted by an autosomal recessive manner. These findings suggest that WMS mice may provide a good model that will be useful in identifying deafness genes in humans.
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