The interplay between homeostatic synaptic plasticity and functional dendritic compartments.
The interplay between homeostatic synaptic plasticity and functional dendritic compartments.
复制标题
稳态突触可塑性和功能性树突区室之间的相互作用。
DOI：
10.1152/jn.00074.2006
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发表时间：
2006
期刊：
影响因子：
--
通讯作者：
Segev,Idan
中科院分区：
文献类型：
--
作者：
Rabinowitch,Ithai;Segev,Idan
稳态突触可塑性（Homeostatic synaptic plasticity，HSP）是神经元活动缓慢调节的重要机制。每当活动长期增强时，HSP就会削弱树突中突触的重量，反之亦然。由于树突状细胞的形态和其电特性划分的树突状细胞树的功能区室，我们着手探讨HSP和树突状细胞区室化之间的相互作用。为此，我们使用了一个详细的模型，一个CA1锥体神经元接收大量的活动依赖性塑料突触，并开发了一种新的方法来指定功能树突状亚基。我们发现，树突状区室化的程度和HSP的位置特异性密切相关。在单个突触水平上操作的局部HSP机制将把神经元视为多单元分布式系统，每个单元由许多突触组成，因此将支持树枝状区室化，而修改所有突触的全局HSP机制一致地将神经元视为单个集中单元。局部和全局HSP都可以成功地平衡树突活性的持续性、细胞范围的扰动。在局部HSP机制和全局HSP机制下，整个树突中突触重量的空间分布将显著不同。我们提出了一个实验范例，以解开哪种类型的HSP机制在树突状树。这个问题的答案将对我们理解神经元的功能组织具有重要意义。
Homeostatic synaptic plasticity (HSP) is an important mechanism attributed with the slow regulation of the neuron's activity. Whenever activity is chronically enhanced, HSP weakens the weights of the synapses in the dendrites and vice versa. Because dendritic morphology and its electrical properties partition the dendritic tree into functional compartments, we set out to explore the interplay between HSP and dendritic compartmentalization. For this purpose, we used a detailed model of a CA1 pyramidal neuron receiving a large number of activity-dependent plastic synapses and developed a novel approach for specifying functional dendritic subunits. We found that the degree of dendritic compartmentalization and the location-specificity of HSP are strongly tied. A local HSP mechanism, operating at the level of the individual synapse, will regard the neuron as a multiunit distributed system, each unit consisting of many synapses, and will thus support dendritic compartmentalization, whereas a global HSP mechanism, modifying all synapses in unison, will treat the neuron as a single centralized unit. Both local and global HSP can successfully counterbalance persistent, cell-wide perturbations of dendritic activity. The spatial distribution of synaptic weights throughout the dendrites will markedly differ under the local versus global HSP mechanisms. We suggest an experimental paradigm to unravel which type of HSP mechanism operates in the dendritic tree. The answer to this question will have important implications to our understanding of the functional organization of the neuron.