A switching role of postsynaptic calcium in the induction of long-term potentiation or long-term depression in visual cortex
A switching role of postsynaptic calcium in the induction of long-term potentiation or long-term depression in visual cortex
复制标题
突触后钙在视觉皮层长期增强或长期抑制诱导中的转换作用
DOI：
10.1006/smns.1996.0038
复制
发表时间：
1996
期刊：
影响因子：
--
通讯作者：
H. Yasuda
中科院分区：
文献类型：
--
作者：
T. Tsumoto;H. Yasuda
摘要长时程增强（LTP）和抑制（LTD）被认为是大脑新皮层神经元功能变化的经验依赖性过程的起始步骤。作为LTP和LTD的诱导机制，有人假设，输入相关的Ca 2+的上升超过一定的阈值，在突触后位点导致LTP，而较低的上升低于阈值导致LTD。为了测试这一Ca 2+开关假说，显微镜荧光测定法与Ca 2+指标，如Fura-2已被采用。在这篇评论中，这个Fura-2方法的问题进行了描述，并与其他指标具有较弱的Ca 2+螯合作用得到的结果简要提及。实验结果表明，参与钙/钙调素依赖性蛋白激酶II（CaMKII）和蛋白磷酸酶（钙调神经磷酸酶）也进行了审查，并提出了一个模型，其中包括时空动态的钙离子和细胞内的位置作为变量的钙离子开关假说的修改。
Abstract Long-term potentiation (LTP) and depression (LTD) are considered to be an initial step in processes governing experience-dependent changes in neuronal function in cerebral neocortex. As a mechanism for the induction of LTP and LTD, it is hypothesized that an input-associated rise of Ca2+beyond a certain threshold at postsynaptic sites leads to LTP while a lower rise below the threshold leads to LTD. To test this Ca2+-switching hypothesis, the method of microscopic fluorometry with Ca2+indicators such as fura-2 has been employed. In this review, problems with this fura-2 method are described, and results obtained with other indicators having weaker Ca2+-chelating action are mentioned briefly. Experimental results indicating the involvement of Ca2+/calmodulin-dependent protein kinase II (CaMKII) and protein phosphatase (calcineurin) are also reviewed, and a model that includes the spatiotemporal dynamics of Ca2+and the intracellular location of both enzymes as variables is proposed as a modification of the Ca2+-switching hypothesis.