Ca2+ imaging of mouse neocortical interneurone dendrites:: Contribution of Ca2+-permeable AMPA and NMDA receptors to subthreshold Ca2+ dynamics
Ca2+ imaging of mouse neocortical interneurone dendrites:: Contribution of Ca2+-permeable AMPA and NMDA receptors to subthreshold Ca2+ dynamics
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DOI：
10.1113/jphysiol.2003.042598
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发表时间：
2003-08-15
影响因子：
5.5
通讯作者：
Tamas, G
中科院分区：
文献类型：
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作者：
Goldberg, JH;Yuste, R;Tamas, G
在第二项研究中，我们将双光子钙成像与全细胞记录以及解剖学重建相结合，以直接描述三种类型的小鼠初级视皮层（V1）颗粒上层中间神经元中由突触诱发的钙信号：小白蛋白阳性的快速发放神经元（FS）、钙结合蛋白阳性的不规则发放神经元（IS）以及适应性细胞（AD）。我们观察到，阈下突触激活诱发的钙信号在局部局限于单个树突区室。在AD和IS细胞中，这些信号由N - 甲基 - D - 天冬氨酸受体（NMDARs）介导，而在FS细胞中，钙通透性α - 氨基 - 3 - 羟基 - 5 - 甲基 - 4 - 异恶唑丙酸受体（CP - AMPARs）提供了一种额外的且在动力学上不同的内流。此外，即使是单次阈下突触激活所诱发的树突钙内流也比反向传播的动作电位更大。我们的研究结果表明，NMDARs在中间神经元的阈下钙动力学中起主导作用，并揭示了CP - AMPARs对皮质中间神经元的一个特定亚类的功能贡献。这些数据突显了不同类型的中间神经元在树突信号处理方面的不同策略。
In this second study, we have combined two-photon calcium imaging with whole-cell recording and anatomic reconstructions to directly characterize synaptically evoked calcium signals in three types of mouse V1 supragranular interneurones: parvalbumin-positive fast spikers (FS), calretinin-positive irregular spikers (IS), and adapting cells (AD). We observed that subthreshold synaptic activation evoked calcium signals locally restricted to individual dendritic compartments. These signals were mediated by NMDA receptors (NMDARs) in AD and IS cells, whereas in FS cells, calcium-permeable AMPA receptors (CP-AMPARs) provided an additional and kinetically distinct influx. Furthermore, even a single, subthreshold synaptic activation evoked a larger dendritic calcium influx than backpropagating action potentials. Our results demonstrate that NMDARs dominate subthreshold calcium dynamics in interneurones and reveal the functional contribution of CP-AMPARs to a specific subclass of cortical interneurone. These data highlight different strategies in dendritic signal processing by distinct classes of interneurones.