Structural dynamics of synapses in vivo correlate with functional changes during experience-dependent plasticity in visual cortex.
Structural dynamics of synapses in vivo correlate with functional changes during experience-dependent plasticity in visual cortex.
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DOI：
10.1523/jneurosci.1661-10.2010
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发表时间：
2010-08-18
期刊：
影响因子：
--
通讯作者：
Sur M
中科院分区：
文献类型：
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作者：
Tropea D;Majewska AK;Garcia R;Sur M
活动对神经回路的影响是复杂的，涉及功能和结构的变化，而它们之间的相互作用在很大程度上是未知的。我们利用小鼠视觉皮层反应的光学成像以及对第5层神经元表层树突棘的双光子成像，在体监测小鼠视觉皮层的网络功能和突触结构动态。出生后在黑暗中饲养导致完全缺乏视觉会抑制视觉反应，并使树突棘的动态和形态向不成熟状态转变。黑暗饲养后视觉的影响在很大程度上取决于暴露的时间：在数天的时间里，功能和结构的变化在时间上是相关的，即光线在增加视觉驱动活动的同时稳定树突棘。长期光照的影响可以通过在黑暗中实验性地增强抑制性信号来部分模拟。然而，短暂的光照会导致皮层反应迅速、短暂且依赖NMDA的增加，同时伴随着树突棘动态性的增加。这些发现表明，视觉经验会诱导皮层回路的快速重组，随后是一段稳定期，并证明了单个突触的动态变化与皮层网络功能之间的密切关系。
The impact of activity on neuronal circuitry is complex, involving both functional and structural changes whose interaction is largely unknown. We have used optical imaging of mouse visual cortex responses and two-photon imaging of superficial layer spines on layer 5 neurons to monitor network function and synaptic structural dynamics in the mouse visual cortex in vivo. Total lack of vision due to dark-rearing from birth dampens visual responses and shifts spine dynamics and morphologies toward an immature state. The effects of vision after dark rearing are strongly dependent on the timing of exposure: over a period of days, functional and structural changes are temporally related such that light stabilizes spines while increasing visually-driven activity. The effects of long-term light exposure can be partially mimicked by experimentally enhancing inhibitory signaling in the darkness. Brief light exposure, however, results in a rapid, transient, NMDA-dependent increase of cortical responses, accompanied by increased dynamics of dendritic spines. These findings indicate that visual experience induces rapid reorganization of cortical circuitry followed by a period of stabilization, and demonstrate a close relationship between dynamic changes at single synapses and cortical network function.