Interregional synaptic competition in neurons with multiple STDP-inducing signals
Interregional synaptic competition in neurons with multiple STDP-inducing signals
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DOI：
10.1152/jn.00612.2010
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发表时间：
2011-03-01
影响因子：
2.5
通讯作者：
Segev, Idan
中科院分区：
文献类型：
--
作者：
Bar Ilan, Lital;Gidon, Albert;Segev, Idan
Bar Ilan L，Gidon A，Segev I.具有多种STDP诱导信号的神经元的区域间突触竞争。J Neurophysiol 105：989-998，2011.首次发表于2010年12月1日; doi：10.1152/jn.00612.2010.-新皮层第5层（L5）锥体细胞具有至少两个锋电位起始区：Na（+）锋电位产生于索马附近，Ca 2（+）锋电位产生于顶端树突簇。这些尖峰相互作用，并作为突触可塑性的信号。目前的计算研究探讨了在一个神经元中具有两个尖峰时间依赖可塑性（STDP）信号的含义，每个信号都具有各自的突触“瞳孔”区域群体。“在L5锥体神经元的详细模型中，属于不同区域的突触之间出现竞争，在每个区域内突触之间的竞争之上，这是STDP机制的特征。区域间的竞争导致一组突触的加强，这最终控制了细胞放电，而其他区域的突触则被削弱。这种新型的竞争是固有的树突与多个区域的信号Hebbian可塑性。令人惊讶的是，这种区域间竞争甚至存在于两个相同的耦合隔间的简化模型中。我们发现，在L5锥体细胞模型中，当Ca 2（+）峰的诱导需要反向传播动作电位（BPAP）时，不同的突触亚群“和平共处”。因此，我们提出了一个新的关键作用的BPAP，以维持整个树突树的突触效能之间的平衡，从而维持整个神经元的功能完整性。
Bar Ilan L, Gidon A, Segev I. Interregional synaptic competition in neurons with multiple STDP-inducing signals. J Neurophysiol 105: 989-998, 2011. First published December 1, 2010; doi: 10.1152/jn.00612.2010.-Neocortical layer 5 (L5) pyramidal cells have at least two spike initiation zones: Na(+) spikes are generated near the soma, and Ca2(+) spikes at the apical dendritic tuft. These spikes interact with each other and serve as signals for synaptic plasticity. The present computational study explores the implications of having two spike-timing-dependent plasticity (STDP) signals in a neuron, each with its respective regional population of synaptic "pupils." In a detailed model of an L5 pyramidal neuron, competition emerges between synapses belonging to different regions, on top of the competition among synapses within each region, which characterizes the STDP mechanism. Interregional competition results in strengthening of one group of synapses, which ultimately dominates cell firing, at the expense of weakening synapses in other regions. This novel type of competition is inherent to dendrites with multiple regional signals for Hebbian plasticity. Surprisingly, such interregional competition exists even in a simplified model of two identical coupled compartments. We find that in a model of an L5 pyramidal cell, the different synaptic subpopulations "live in peace" when the induction of Ca2(+) spikes requires the back-propagating action potential (BPAP). Thus we suggest a new key role for the BPAP, to maintain the balance between synaptic efficacies throughout the dendritic tree, thereby sustaining the functional integrity of the entire neuron.