Study on plasticity of visual system by thyroid hormone
Project/Area Number |
60570076
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Research Category |
Grant-in-Aid for General Scientific Research (C)
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Allocation Type | Single-year Grants |
Research Field |
環境生理学(含体力医学・栄養生理学)
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Research Institution | Gunma University |
Principal Investigator |
SUZUKI Mitsuo Professor , Institute of Endocrinology, Gunma University, 内分泌研究所, 教授 (60008597)
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Co-Investigator(Kenkyū-buntansha) |
ISHIKAWA Koichi Assistant Professor , Institute of Endocrinology, Gunma University, 内分泌研究所, 助手 (80143238)
KATO Masakatsu Assistant Professor , Institute of Endocrinology, Gunma University, 内分泌研究所, 助手 (90143239)
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Project Period (FY) |
1985 – 1986
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Project Status |
Completed (Fiscal Year 1986)
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Budget Amount *help |
¥1,600,000 (Direct Cost: ¥1,600,000)
Fiscal Year 1986: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 1985: ¥1,100,000 (Direct Cost: ¥1,100,000)
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Keywords | thyroid hormone / <T_4> / <T_3> / plasticity / evoked potential / visual cortex / 誘発電位 / 粘液水腫 / クレチン症 / ソマトスタチン |
Research Abstract |
It has been known that thyroid hormone affects morphological integrity of the visual cortex of developing rats as well as nervous functions including mental states. In order to find the functional changes in the central nervous system, caused by thyroid hormone, we applied photic repetitive stimulation to the visual system of rats in various thyroid states. Normal ( <I> ), thyroidectomized 3 to 11 week prior to the experiments ( <II> ) and thyroidectomized- <T_4> (0.1 mg/kg) supplemented ( <III> ) were used. After anesthesia with Nembutal (55 mg/kg), photic stimulation (2 joules, 5 sec interval, 25 cm) was given to the rats. To record evoked potentials (Ep) elicited by the photic stimulation a glass electrode was inserted into the visual cortex Ve (Bregma-8.5-9.5 mm, <lambda> 3.0 mm, d 0.2-0.5 mm) and also the lateral geniculate nucleus (LGN). Group II rats showed a prolonged latency in Ep at VC (+28.0%) and also at LGN (+29.1%) at the levels of p<0.01 in both areas. These changes were observed as early as 2 days after <T_4> and also 1 day after <T_3> (0.05 mg/kg) injections, suggesting that thyroid hormone is required to maintain the functional integrity of the visual system.
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Report
(1 results)
Research Products
(6 results)