The subspine organization of actin fibers regulates the structure and plasticity of dendritic spines
The subspine organization of actin fibers regulates the structure and plasticity of dendritic spines
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DOI：
10.1016/j.neuron.2008.01.013
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发表时间：
2008-03-13
期刊：
影响因子：
16.2
通讯作者：
Kasai, Haruo
中科院分区：
文献类型：
--
作者：
Honkura, Naoki;Matsuzaki, Masanori;Kasai, Haruo
突触的功能和可塑性取决于由肌动蛋白细胞骨架决定的树突棘的物理结构。我们研究了大鼠海马片CA1锥体神经元单个棘内丝状(F-)肌动蛋白的组织结构。利用融合到P-肌动蛋白上的绿色荧光蛋白的双光子光激活，我们发现脊柱顶端的一个动态的β-肌动蛋白池可以快速地跑步性地产生扩张力。脊柱底部稳定的F-肌动蛋白池的大小取决于脊柱体积。重复的双光子去谷氨酸形成了第三个F-肌动蛋白池，扩大了脊柱。脊椎经常将这个“膨胀池”释放到树突干中，但这个池必须受到脊椎颈部的物理限制，才能持久地扩大。Ca~(2+)/钙调蛋白依赖的蛋白激酶II调节这种限制。因此，脊椎具有一种精细的机械性质，由肌动蛋白纤维调节。
Synapse function and plasticity depend on the physical structure of dendritic spines as determined by the actin cytoskeleton. We have investigated the organization of filamentous (F-) actin within individual spines on CA1 pyramidal neurons in rat hippocampal slices. Using two-photon photoactivation of green fluorescent protein fused to P-actin, we found that a dynamic pool of beta-actin at the tip of the spine quickly treadmilled to generate an expansive force. The size of a stable F-actin pool at the base of the spine depended on spine volume. Repeated two-photon uncaging of glutamate formed a third pool of F-actin and enlarged the spine. The spine often released this "enlargement pool" into the dendritic shaft, but the pool had to be physically confined by a spine neck for the enlargement to be long-lasting. Ca2+/calmodulin-dependent protein kinase II regulated this confinement. Thus, spines have an elaborate mechanical nature that is regulated by actin fibers.