Dendrites Impact the Encoding Capabilities of the Axon
Dendrites Impact the Encoding Capabilities of the Axon
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DOI：
10.1523/jneurosci.5431-13.2014
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发表时间：
2014-06-11
影响因子：
5.3
通讯作者：
Segev, Idan
中科院分区：
文献类型：
--
作者：
Eyal, Guy;Mansvelder, Huibert D.;Segev, Idan
这项研究突出了树突树（神经元的输入区域）对轴突（输出区域）编码能力的新的和强大的直接影响。我们发现，树突状的乔木（其阻抗负载）的大小强烈调制的形状的动作电位（AP）在轴突起始段的发病，它是加速在神经元具有较大的树突状表面积。AP发作的快速性是确定轴突尖峰对突触输入的快速变化进行编码（锁相）的能力的关键。因此，我们的研究结果意味着具有较大树突的神经元具有改善的编码能力。这种“树突大小效应”的探讨分析以及数值，在简化和详细的模型的3D重建层2/3皮质锥体细胞的大鼠和人类。棘波相位锁定调制输入的截止频率增加，从100至200 Hz的年轻大鼠的锥体细胞的400-600 Hz的人类细胞。在后一种情况下，在类似体内的条件下，锁相达到接近1 KHz。这项工作突出了新的和功能深刻的树突树和轴突初始段之间的串扰，提供了新的理解神经元作为复杂的非线性输入/输出设备。
This study highlights a new and powerful direct impact of the dendritic tree (the input region of neurons) on the encoding capability of the axon (the output region). We show that the size of the dendritic arbors (its impedance load) strongly modulates the shape of the action potential (AP) onset at the axon initial segment; it is accelerated in neurons with larger dendritic surface area. AP onset rapidness is key in determining the capability of the axonal spikes to encode (phase lock to) rapid changes in synaptic inputs. Hence, our findings imply that neurons with larger dendritic arbors have improved encoding capabilities. This "dendritic size effect" was explored both analytically as well as numerically, in simplified and detailed models of 3D reconstructed layer 2/3 cortical pyramidal cells of rats and humans. The cutoff frequency of spikes phase locking to modulated inputs increased from 100 to 200 Hz in pyramidal cells of young rats to 400-600 Hz in human cells. In the latter case, phase locking reached close to 1 KHz in in vivo-like conditions. This work highlights new and functionally profound cross talk between the dendritic tree and the axon initial segment, providing new understanding of neurons as sophisticated nonlinear input/output devices.