Bidirectional synaptic plasticity correlated with the magnitude of dendritic calcium transients above a threshold
Bidirectional synaptic plasticity correlated with the magnitude of dendritic calcium transients above a threshold
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DOI：
10.1152/jn.2001.85.1.399
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发表时间：
2001-01-01
影响因子：
2.5
通讯作者：
Connor, JA
中科院分区：
文献类型：
--
作者：
Cormier, RJ;Greenwood, AC;Connor, JA
突触后Ca 2+瞬变的幅度被认为影响与学习和记忆相关的活动依赖性突触可塑性。大的Ca 2+瞬变与长时程增强（LTP）的诱导有关，而较小的Ca 2+瞬变与长时程抑制（LTD）有关。然而，一个直接的关系尚未被证明之间的钙离子测量和方向的突触可塑性在相同的细胞，使用一个诱导协议。在这里，我们使用谷氨酸离子导入诱导海马CA 1区神经元注射钙离子指示剂Fura-2的钙瞬变。在离子电渗疗法之前和之后的一个或两个突触通路的测试刺激表明，突触可塑性的方向与高于阈值的谷氨酸诱导的Ca 2+水平相关，低于阈值则没有可塑性发生（类似于180 nM）。相对较低的Ca 2+水平（180-500 nM）通常导致突触传递的LTD，而较高的水平（>500 nM）通常导致LTP。未能显示可塑性与两个不同范围内的Ca 2+水平相关：
The magnitude of postsynaptic Ca2+ transients is thought to affect activity-dependent synaptic plasticity associated with learning and memory. Large Ca2+ transients have been implicated in the induction of long-term potentiation (LTP), while smaller Ca2+ transients have been associated with long-term depression (LTD). However, a direct relationship has not been demonstrated between Ca2+ measurements and direction of synaptic plasticity in the same cells, using one induction protocol. Here, we used glutamate iontophoresis to induce Ca2+ transients in hippocampal CA1 neurons injected with the Ca2+- indicator fura-2. Test stimulation of one or two synaptic pathways before and after iontophoresis showed that the direction of synaptic plasticity correlated with glutamate-induced Ca2+ levels above a threshold, below which no plasticity occurred (similar to 180 nM). Relatively low Ca2+ levels (180-500 nM) typically led to LTD of synaptic transmission and higher levels (>500 nM) often led to LTP. Failure to show plasticity correlated with Ca2+ levels in two distinct ranges: