Spine-neck geometry determines NMDA receptor-dependent Ca2+ signaling in dendrites
Spine-neck geometry determines NMDA receptor-dependent Ca2+ signaling in dendrites
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DOI：
10.1016/j.neuron.2005.03.015
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发表时间：
2005-05-19
期刊：
影响因子：
16.2
通讯作者：
Kasai, H
中科院分区：
文献类型：
--
作者：
Noguchi, J;Matsuzaki, M;Kasai, H
NMDA敏感性谷氨酸受体（NMDARs）介导的胞浆Ca2+浓度（[Ca2+]（i））增加对突触可塑性很重要。我们研究了各种各样的树突棘大鼠CA1锥体神经元在急性海马脑片。双光子uncaging和Ca2+成像显示，NMDAR介导的电流增加与脊髓头体积，即使是最小的脊柱包含了显着数量的NMDAR。通过NMDAR进入脊柱头部的Ca2+的命运由脊柱颈部的形状（长度和半径）决定。较大的棘有颈部，允许更多的Ca2+流出到树突干，而较小的棘表现出更大的增加[Ca2+]（i）内的棘室作为一个较小的Ca2+通量通过颈部的结果。因此，棘颈几何形状是棘Ca2+信号传导的重要决定因素，允许小棘成为孤立诱导长时程增强的优先位点。
Increases in cytosolic Ca2+ concentration ([Ca2+](i)) mediated by NMDA-sensitive glutamate receptors (NMDARs) are important for synaptic plasticity. We studied a wide variety of dendritic spines on rat CA1 pyramidal neurons in acute hippocampal slices. Two-photon uncaging and Ca2+ imaging revealed that NMDAR-mediated currents increased with spine-head volume and that even the smallest spines contained a significant number of NMDARs. The fate of Ca2+ that entered spine heads through NMDARs was governed by the shape (length and radius) of the spine neck. Larger spines had necks that permitted greater efflux of Ca2+ into the dendritic shaft, whereas smaller spines manifested a larger increase in [Ca2+](i) within the spine compartment as a result of a smaller Ca2+ flux through the neck. Spine-neck geometry is thus an important determinant of spine Ca2+ signaling, allowing small spines to be the preferential sites for isolated induction of long-term potentiation.