| Project/Area Number |
14570057
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Environmental physiology (including Physical medicine and Nutritional physiology)
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| Research Institution | Osaka Electro-Communication University |
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Principal Investigator |
HOSONO Takayoshi Osaka Electro-Communication University, Faculty of Engineering, Professor, 工学部, 教授 (60294104)
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| Co-Investigator(Kenkyū-buntansha) |
FUKUDA Hirotsugu Osaka University, Graduate School of Medicine, Assistant Professor, 大学院・医学系研究科, 助手 (40324751)
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| Project Period (FY) |
2002 – 2003
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| Project Status |
Completed (Fiscal Year 2003)
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| Budget Amount *help |
¥3,500,000 (Direct Cost: ¥3,500,000)
Fiscal Year 2003: ¥1,000,000 (Direct Cost: ¥1,000,000)
Fiscal Year 2002: ¥2,500,000 (Direct Cost: ¥2,500,000)
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| Keywords | brain damage / newborn / environmental temberature / rat / thermoregulation / optic recording / auditory brainstem response / 脳性脳幹反応 / 低酸素 |
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| Research Abstract |
In order to investigate the effect of brain cooling of the neonate suffered hypoxic-ischemic brain-damage, we performed experiments using animal model. Under the inspired anesthesia, we ligated left common carotid artery of the 7-day-old rat neonate, and exposed them to the hypoxic air (oxygen 8%). After the hypoxic exposure, we divided the rat neonates to three groups. The first group (hypothermia group) was kept in a room of low environmental temperature for 24 hr, which led the rats to the hypothermia (30 degree). The second group (normothermia group) was kept in a room of normal temperature for 24 hr, which kept the rat body temperature in normothermia. The third group was a control, which had a sham operation. After rearing for three months, we performed auditory brainstem response (ABR) for three groups. ABR was successfully recorded in all the rats under light anesthesia. The interpeak latency of III and V peaks of the normothermia group was significantly elongated than those of the hypothermia and control group. The ratio of the amplitude of V peak versus I peak of the normothermia group was also significantly small than those of the other groups. The inferior colliculus of the normothermia group was significantly atrophic than those of the other groups by using light microscope and imaging-data processing software. These findings indicate that high environmental temperature for the neonate rats after the hypoxic-ischemic insult caused more damages in rat midbrain function than low environmental temperature does. We also performed preliminary investigation on the function of neuronal circuit using optic recording, and found that optic recording using low perfusion temperature might be a useful investigation tools for the study of damaged brain function of suffered neonate animal models.
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