| Project/Area Number |
09671735
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research (C)
|
| Allocation Type | Single-year Grants |
|---|
| Section | 一般 |
|---|
| Research Field |
Otorhinolaryngology
|
|---|
| Research Institution | University of Tokyo |
|---|
Principal Investigator |
TAKEUCHI Naonobu Univ of Tokyo, Dept of Otolaryngology, Assistant, 医学部・附属病院, 助手 (40280945)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
NAITO Rie Univ of Tokyo, Dept of Otolaryngology, Assistant, 保健管理センター, 助手 (10282667)
MUROFUSHI Toshihisa Univ of Tokyo, Dept of Otolaryngology, Assistant, 医学部・附属病院, 講師 (30242176)
|
|---|
| Project Period (FY) |
1997 – 1998
|
| Project Status |
Completed (Fiscal Year 1998)
|
| Budget Amount *help |
¥2,900,000 (Direct Cost: ¥2,900,000)
Fiscal Year 1998: ¥700,000 (Direct Cost: ¥700,000)
Fiscal Year 1997: ¥2,200,000 (Direct Cost: ¥2,200,000)
|
|---|
| Keywords | regeneration / facial nerve / myelin deficiency / rat / mutant / hamster |
|---|
| Research Abstract |
Experiment 1 "Regeneration of facial nerves in normal rats"
We observed the morphological changes of endoneurium collagen fibers in regeneration of facial nerve fibers of normal rats with transmission and scanning electron microscopes. Wistar rats were underwent intraperitoneal anesthesia and we severed zygomatic branch of facial nerve and conducted epineurial anatomosis using 10-0 nylon sutures. After monitoring the evoked electromyograms at 2, 4, 8 and 12 weeks, we sacrificed the animals and treated for morphological study. In order to observe the three dimensional structure of the collagen fibers clearly, the specimens were immersing in 10% NaOH for 2 days.
Collagen fibers of endoneurium at Week 2 were thinner and their density was slower compared to normal. At Week 4, collagen bundles become tube shaped corresponding to Week 8, the diameter of collagen fibers increased. At Week 12, matrix structure was different from the normal 2-layer structure, and presented thick layers covering the nerve fibers.
In this study, significant proliferation of collagen fibers was observed after severing the nerve, and its regenerated matrix structure was different from the one before severing. This change in matrix could have a definite influence on the recovery of nerve functions.
Experiment 2 "Brainstem function of the mutant hamster with myelin deficiency"
Brainstem functions of the mutant hamster with myelin deficiency were studied by auditory brainstem response and found to be abnormal in auditory brainstem pathway and auditory nerve.
Experiment 3 "Pathology of brainstem in the mutant hamster with myelin deficiency"
Brainstem pathology of facial nerve fibers of the mutant hamster was investigated by light microscopy and electron microscopy and demonstrated to be abnormal in the facial nerve as well as in the spiral ganglion and auditory brainstem pathway. No regeneration was found in the facial nerve.
|
