| Budget Amount *help |
¥2,100,000 (Direct Cost: ¥2,100,000)
Fiscal Year 1996: ¥600,000 (Direct Cost: ¥600,000)
Fiscal Year 1995: ¥1,500,000 (Direct Cost: ¥1,500,000)
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| Research Abstract |
To make culture of mature cerebral cortex has been thought to be difficult. Previously, I showed that a part of neurons in 3-4 week-old rat visual cortex can survive for 1 week by making very thin (150 micron) slice. In that case, however, I had only observed neurite outgrowth from and within the slice using fluorescent dyes. It was difficult to observe field potentials by stimulating underlying white matter in a very thin slice. In the present study, I made 400 microns-thick cortical slices. This enabled us to estimate slice viability from electrophysiological aspect.
Population field responses in mature cortical slices disappeared within 4 hours when they were put on a conventional interface-type culture dish in a commerciallyavailable CO2 incubator. Most of the neurons soon showed apparent shrinkage. In contrast, slices which were continuously perfused by culture medium (1.2ml/min) showed field responses over 18 hours. With our previous culture preparing method, considerablly long period was needed for atmosphere in a culture dish to reach equibrium in gas composition, pH,humidity, temperature after they are exposed in room air at the instance of transferring tissues. This may be fatal for adult cortical tissues. Now I am constructing a new system which enables us to conduct a long time recording in a sterilized condition.
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