In vitro study of rat visual cortical plasticity

大鼠视觉皮层可塑性的体外研究

基本信息

批准号：
09480233
负责人：
TOYAMA Keisuke
金额：
$ 8.9万
依托单位：
KYOTO PREFECTURAL UNIVERSITY OF MEDICINE
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
1997
资助国家：
日本
起止时间：
1997 至 1998
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-09480233/
关键词：
PLASTICITY fast LTP slow LTP protein kinase visual cortex staurosporine protein kinase 可塑性視覚野

项目摘要

In vitro study of rat visual cortical plasticityA debate between the prenatal vs. postnatal theory has long been one of the central issues in neuroscience. Recently, it has been shown that two basic structures in the cerebral cortex, the layer and columnar organizations, depend on the gene and learning, respectively. We have been studying the plasticity responsible for learning of the columnar organization in the visual cortex by in vitro approach, investigating the plasticity as long term potentiation (LTP) of synaptic transmission in the rat visual cortical slices. We found two types of LTPs. Fast (fLTP) developed almost immediately (in 5 min.) after theta-burst stimulation of the white matter while slow LTP (sLTP) developed gradually (in one hour). The two LTPs exhibited the following distinct properties. First, the fLTP occurred in the adult as well as young rat slices, while the sLTP preferentially occurred in the young slices. Second, the induction of the fLTP was blocked by blockers of the NMDA receptors (APV) while that of the sLTP was blocked by blockers of the voltage-gated Ca channels as well as those of the protein and RNA syntheses. Third, sLTP expressed in the first and second order geniculo-cortical synapses while fLTP expressed in the axon collateral synapses in layers 5 and 6. These findings indicate that the sLTP is the substrate for the developmental plasticity underlying formation of columnar structures such as the ocular dominance and orientation columns while the fLTP is that for the adult plasticity underlying learning phenomena such as adaptation.

大鼠视觉皮层可塑性的体外研究产前与产后理论之间的争论长期以来一直是神经科学的核心问题之一。最近，研究表明，大脑皮层的两种基本结构，层状组织和柱状组织，分别取决于基因和学习。我们一直在通过体外方法研究负责学习视觉皮层柱状组织的可塑性，研究可塑性作为大鼠视觉皮层切片中突触传递的长期增强（LTP）。我们发现了两种类型的 LTP。快 (fLTP) 在白质 θ 爆发刺激后几乎立即（5 分钟内）形成，而慢 LTP (sLTP) 逐渐形成（1 小时内）。这两种 LTP 表现出以下不同的特性。首先，fLTP 发生在成年和幼鼠切片中，而 sLTP 优先发生在幼鼠切片中。其次，fLTP 的诱导被 NMDA 受体 (APV) 阻断剂阻断，而 sLTP 的诱导被电压门控 Ca 通道以及蛋白质和 RNA 合成阻断剂阻断。第三，sLTP 在第一和第二级膝皮质突触中表达，而 fLTP 在第 5 层和第 6 层的轴突侧支突触中表达。这些发现表明 sLTP 是形成柱状结构（例如眼部）的发育可塑性的底物。优势和方向列，而 fLTP 是针对成人可塑性的基础学习现象（例如适应）。