Project/Area Number |
11671078
|
Research Category |
Grant-in-Aid for Scientific Research (C)
|
Allocation Type | Single-year Grants |
Section | 一般 |
Research Field |
Embryonic/Neonatal medicine
|
Research Institution | Institute for Developmental Research, Aichi Human Service Center |
Principal Investigator |
NAKANISHI Keiko Dept. of Physiology, Senior Researcher, 生理学部, 主任研究員 (50280813)
|
Project Period (FY) |
1999 – 2002
|
Project Status |
Completed (Fiscal Year 2002)
|
Budget Amount *help |
¥2,800,000 (Direct Cost: ¥2,800,000)
Fiscal Year 2002: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 2001: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 2000: ¥700,000 (Direct Cost: ¥700,000)
Fiscal Year 1999: ¥1,100,000 (Direct Cost: ¥1,100,000)
|
Keywords | X-irradiation / microcephaly / cultured neuron / synapse formation / GABA / シナプス / 同調活動 |
Research Abstract |
Prenatal X-irradiation can induce microcephaly in the brain of offsprings. To investigate the mechanism how temporary stress in utero induces neurological disorders remaining throughout their life, synapse formation of neocortical neurons from prenatally X-irradiated rats was examined. Total number of neocortical neurons from prenatally (E16) X-irradiated rats decreased by 16 % relative to control when examined at E17, while the ratio of GABA-positive neurons to MAP2-positive ones increased 2.2 folds of control. Cultured neocortical neurons from normal embryonic rats exhibit synchronized synaptically-driven rhythmic depolarizing potentials (RDPs) after 7-10 DIV. Although RDPs were observed in X-irradiated neurons as well as in control neurons, their amplitude and the number of spikes decreased. These results suggest that inhibitory inputs hold predominance over excitatory inputs in X-irradiated rat's brain, although their neurons have the ability to form synapses. Increased inhibitory inputs might give rise to subsequent neurological disorders of X-irradiated rats.
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