Experience leaves a lasting structural trace in cortical circuits.
Experience leaves a lasting structural trace in cortical circuits.
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经验在皮质回路中留下了持久的结构痕迹。
DOI：
10.1038/nature07487
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发表时间：
2009-01-15
期刊：
影响因子：
64.8
通讯作者：
Hübener M
中科院分区：
文献类型：
--
作者：
Hofer SB;Mrsic-Flogel TD;Bonhoeffer T;Hübener M
感觉体验对哺乳动物新皮层神经元回路的功能和未来表现具有重要影响。突触连接的重组被认为是皮层回路储存感官世界信息的一种机制。兴奋性突触结构，如树突棘，是动态的实体，在整个生命过程中对感觉输入的改变保持敏感。然而，树突棘水平的结构变化是否能比原始经验持续更长时间，从而为长期信息存储提供形态学基础，目前尚不清楚。在此，我们追踪了在单眼反复闭眼诱导的眼特异性反应可塑性过程中，成年小鼠视觉皮层功能限定区域锥体神经元顶端树突的脊柱动力学。第一次MD发作使脊柱形成率增加了一倍，从而增加了脊柱密度。这种效应只发生在双眼皮层的第5层细胞上，在这里，大多数神经元对未被剥夺的眼睛的反应增强。双目视力恢复使脊柱动力学恢复到基线水平，但绝对脊柱密度仍然升高，许多md诱导的脊柱在功能恢复期间持续存在。值得注意的是，当同一只眼睛第二次闭上时，脊椎的增加并没有再增加。这种结构可塑性的缺乏与眼睛特定反应的强劲变化相对抗，这种变化在重复剥夺时发生得更快。因此，在第一次MD经验中增加的脊柱可能为随后的功能转变提供结构基础。这些结果提供了功能可塑性和特定突触重排之间的紧密联系，揭示了先前经验如何存储在皮层回路中的机制。
Sensory experiences exert a powerful influence on the function and future performance of neuronal circuits in the mammalian neocortex. Restructuring of synaptic connections is believed to be one mechanism by which cortical circuits store information about the sensory world. Excitatory synaptic structures, such as dendritic spines, are dynamic entities which remain sensitive to alteration of sensory input throughout life. It remains unclear, however, whether structural changes at the level of dendritic spines can outlast the original experience and thereby provide a morphological basis for long-term information storage. Here we follow spine dynamics on apical dendrites of pyramidal neurons in functionally-defined regions of adult mouse visual cortex during plasticity of eye-specific responses induced by repeated closure of one eye (monocular deprivation, MD). The first MD episode doubled the rate of spine formation, thereby increasing spine density. This effect was specific to layer 5 cells located in binocular cortex where most neurons increase their responsiveness to the non-deprived eye. Restoring binocular vision returned spine dynamics to baseline levels, but absolute spine density remained elevated and many MD-induced spines persisted during this period of functional recovery. Remarkably, spine addition did not increase again when the same eye was closed for the second time. This absence of structural plasticity stands out against the robust changes of eye specific responses which occur even faster upon repeated deprivation. Thus, spines added during the first MD experience might provide a structural basis for subsequent functional shifts. These results provide a strong link between functional plasticity and specific synaptic rearrangements, revealing a mechanism of how prior experiences could be stored in cortical circuits.
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影响因子：
16.2
作者：
Holtmaat, AJGD;Trachtenberg, JT;Svoboda, K
通讯作者：
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