Cooperative astrocyte and dendritic spine dynamics at hippocampal excitatory synapses
Cooperative astrocyte and dendritic spine dynamics at hippocampal excitatory synapses
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DOI：
10.1523/jneurosci.1302-06.2006
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发表时间：
2006-08-30
影响因子：
5.3
通讯作者：
Murai, Keith K.
中科院分区：
文献类型：
--
作者：
Haber, Michael;Zhou, Lei;Murai, Keith K.
越来越多的证据重新定义了神经元-神经胶质细胞在中枢神经系统突触中相互作用的重要性。星形胶质细胞与突触前和突触后结构形成"三重"复合体，并调节突触传递和可塑性。尽管我们了解神经元-神经胶质细胞关系在生理环境中的重要性，但对星形胶质细胞和突触之间的结构相互作用知之甚少。在过去，这一直很难探索，因为研究一直受到缺乏一个系统，保留在大脑中观察到的复杂神经元-胶质细胞关系的阻碍。在这里，我们提出了一个系统，可用于表征星形胶质细胞的过程和突触结构之间的错综复杂的关系，在原位使用器官型海马切片，制备，保留了星形胶质细胞-突触相互作用的三维结构。使用延时共聚焦成像，我们证明，星形胶质细胞可以迅速延长和收缩细进程从事和脱离运动突触后树突棘。令人惊讶的是，平均而言，星形胶质细胞的运动性高于树突棘，可能依赖于肌动蛋白为基础的细胞骨架重组。星形胶质细胞过程的变化通常与棘的变化相协调，并且星形胶质细胞-棘的相互作用在较大的棘处稳定。我们的研究结果表明，星形胶质细胞的动态结构变化有助于控制海马突触神经元-胶质细胞通讯的程度。
Accumulating evidence is redefining the importance of neuron-glial interactions at synapses in the CNS. Astrocytes form "tripartite" complexes with presynaptic and postsynaptic structures and regulate synaptic transmission and plasticity. Despite our understanding of the importance of neuron-glial relationships in physiological contexts, little is known about the structural interplay between astrocytes and synapses. In the past, this has been difficult to explore because studies have been hampered by the lack of a system that preserves complex neuron-glial relationships observed in the brain. Here we present a system that can be used to characterize the intricate relationship between astrocytic processes and synaptic structures in situ using organotypic hippocampal slices, a preparation that retains the three-dimensional architecture of astrocyte-synapse interactions. Using time-lapse confocal imaging, we demonstrate that astrocytes can rapidly extend and retract fine processes to engage and disengage from motile postsynaptic dendritic spines. Surprisingly, astrocytic motility is, on average, higher than its dendritic spine counterparts and likely relies on actin-based cytoskeletal reorganization. Changes in astrocytic processes are typically coordinated with changes in spines, and astrocyte-spine interactions are stabilized at larger spines. Our results suggest that dynamic structural changes in astrocytes help control the degree of neuron-glial communication at hippocampal synapses.