Cellular mechanisms of temporal sensitivity in visual cortex neurons.
Cellular mechanisms of temporal sensitivity in visual cortex neurons.
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DOI：
10.1523/jneurosci.5279-09.2010
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发表时间：
2010-03-10
期刊：
影响因子：
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通讯作者：
Palmer LA
中科院分区：
文献类型：
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作者：
Cardin JA;Kumbhani RD;Contreras D;Palmer LA
皮质神经元准确编码其输入的时间模式的能力对皮质功能和感知敏锐度具有重要影响。在这里，我们确定皮层神经元的敏感性的感觉诱发的突触输入的时间的细胞机制。我们发现，时间上一致的输入到初级视皮层第4层神经元引起的尖峰精度和超线性尖峰总和的增加。这种非线性总和的基础是诱发兴奋性电导和相关膜电位反应的变化以及兴奋和抑制之间的窗口延长。此外，第4层中的快速尖峰抑制性中间神经元与兴奋性神经元相比表现出较短的时间敏感性窗口。与第4层神经元对同步输入的增强反应相反，下游皮层层的感觉输入整合更线性，对时间不太敏感。因此，皮层输入层的神经元被独特地优化以检测和编码同步的感觉诱发输入。
The ability of cortical neurons to accurately encode the temporal pattern of their inputs has important consequences for cortical function and perceptual acuity. Here we identify cellular mechanisms underlying the sensitivity of cortical neurons to the timing of sensory-evoked synaptic inputs. We find that temporally coincident inputs to layer 4 neurons in primary visual cortex evoke an increase in spike precision and supralinear spike summation. Underlying this nonlinear summation are changes in the evoked excitatory conductance and the associated membrane potential response and a lengthening of the window between excitation and inhibition. Furthermore, fast-spiking inhibitory interneurons in layer 4 exhibit a shorter window of temporal sensitivity in comparison to excitatory neurons. In contrast to the enhanced response to synchronous inputs by layer 4 neurons, sensory input integration in downstream cortical layers is more linear and less sensitive to timing. Neurons in the input layer of cortex are thus uniquely optimized to detect and encode synchronous sensory-evoked inputs.