Subcellular Imbalances in Synaptic Activity
Subcellular Imbalances in Synaptic Activity
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DOI：
10.1016/j.celrep.2016.01.024
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发表时间：
2016-02-16
期刊：
影响因子：
8.8
通讯作者：
Ikegaya, Yuji
中科院分区：
文献类型：
--
作者：
Takahashi, Naoya;Kobayashi, Chiaki;Ikegaya, Yuji
突触兴奋和抑制（E/I）之间的动态相互作用塑造膜电位波动并确定神经元输出的模式;然而，对单个细胞内这些相互作用的时空组织知之甚少。在这里，我们研究了局部突触兴奋和全局抑制在海马锥体神经元使用功能性树突成像结合抑制性突触后电流的全细胞记录之间的关系。我们发现，树突树的脊柱输入的总和被抵消的比例量的体细胞抑制输入。这种在线的E/I相关性保持在树突状节段，长于50 μ m。然而，在单棘水平，只有22%的活动棘被激活的抑制性输入。这种抑制偶联活性主要发生在头部较大的棘中。这些结果揭示了一个微观的E/I平衡机制，在选定的突触，并可能增加神经信息的准确性。
The dynamic interactions between synaptic excitation and inhibition (E/I) shape membrane potential fluctuations and determine patterns of neuronal outputs; however, the spatiotemporal organization of these interactions within a single cell is poorly understood. Here, we investigated the relationship between local synaptic excitation and global inhibition in hippocampal pyramidal neurons using functional dendrite imaging in combination with whole-cell recordings of inhibitory postsynaptic currents. We found that the sums of spine inputs over dendritic trees were counterbalanced by a proportional amount of somatic inhibitory inputs. This online E/I correlation was maintained in dendritic segments that were longer than 50 mu m. However, at the single spine level, only 22% of the active spines were activated with inhibitory inputs. This inhibition-coupled activity occurred mainly in the spines with large heads. These results shed light on a microscopic E/I-balancing mechanism that operates at selected synapses and that may increase the accuracy of neural information.