Analysis of calcium channels in single spines using optical fluctuation analysis
Analysis of calcium channels in single spines using optical fluctuation analysis
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DOI：
10.1038/35046076
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发表时间：
2000-11-30
期刊：
影响因子：
64.8
通讯作者：
Svoboda, K
中科院分区：
文献类型：
--
作者：
Sabatini, BL;Svoboda, K
大多数突触形成于称为树突棘的小型特化突触后结构 (1)。 Ca2+ 离子通过突触受体和电压敏感 Ca2+ 通道 (VSCC) 流入此类棘，从而触发突触可塑性背后的多种过程 (2)。使用双光子激光扫描显微镜 (3)，我们对大鼠海马切片 (4) 中 CA1 锥体神经元的棘和树突中 Ca2+ 浓度的瞬时变化进行了成像。通过分析这些瞬态中试验间的大波动，我们确定了单个脊柱中 VSCC 的数量和性质。在这里，我们报告每个脊柱包含 1-20 个 VSCC，并且这个数量随着脊柱体积的增加而增加。我们能够检测脊柱上单个 VSCC 的开口。在位于近端树突树上的棘中，VSCC 通常在树突动作电位后以高概率（类似于 0.5）打开。 GABA(B) 受体的激活将顶棘中的这种概率降低至类似于 0.3，但对树突或基底棘中的 VSCC 没有影响。我们的研究表明，VSCC 亚型的空间分布及其调节潜力受到亚微米精度的调节。
Most synapses form on small, specialized postsynaptic structures known as dendritic spines(1). The influx of Ca2+ ions into such spines-through synaptic receptors and voltage-sensitive Ca2+ channels (VSCCs)-triggers diverse processes that underlie synaptic plasticity(2). Using two-photon laser scanning microscopy(3), we imaged action-potential-induced transient changes in Ca2+ concentration in spines and dendrites of CA1 pyramidal neurons in rat hippocampal slices(4). Through analysis of the large trial-to-trial fluctuations in these transients, we have determined the number and properties of VSCCs in single spines. Here we report that each spine contains 1-20 VSCCs, and that this number increases with spine volume. We are able to detect the opening of a single VSCC on a spine. In spines located on the proximal dendritic tree, VSCCs normally open with high probability (similar to0.5) following dendritic action potentials. Activation of GABA(B) receptors reduced this probability in apical spines to similar to0.3 but had no effect on VSCCs in dendrites or basal spines. Our studies show that the spatial distribution of VSCC subtypes and their modulatory potential is regulated with submicrometre precision.