Axonal transmission in the retina introduces a small dispersion of relative timing in the ganglion cell population response.
Axonal transmission in the retina introduces a small dispersion of relative timing in the ganglion cell population response.
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DOI：
10.1371/journal.pone.0020810
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发表时间：
2011
期刊：
影响因子：
3.7
通讯作者：
Fromherz P
中科院分区：
文献类型：
--
作者：
Zeck G;Lambacher A;Fromherz P
视觉刺激在数十种不同的视网膜神经节细胞中引起动作电位。每种神经节细胞类型对给定刺激的反应都有不同的潜伏期，从而将高维输入转化为时间神经代码。不同的视网膜投射神经元细胞之间的第一个尖峰的时间可能会进一步改变沿着轴突传输。本研究的目的是调查视网膜内传导速度是否导致离开眼睛的群体信号的同步或分散。我们使用高密度多晶体管阵列，以微米级的分辨率“成像”了光诱发动作电位沿着单个轴突在兔视网膜中的起始和传输。我们测量了所有视网膜偏心率下轴突群的单峰传导速度分布（1.3±0.3 m/sec，平均值± SD），但包含有髓鞘轴突的中央部分除外。每片视网膜内的速度变化是由显示出较窄且略有不同的平均速度调谐的神经节细胞类型引起的。相同类型的神经节细胞以相似的潜伏期对空间上均匀的刺激作出反应，并以相似的速度进行传导。对于不同类型的神经节细胞，视网膜内传导速度和对闪光刺激的反应潜伏期呈负相关，表明第一尖峰时间的差异增加（高达10毫秒）。同样，对白噪声刺激的成对相关活动的分析表明，传导速度和反应潜伏期呈负相关。视网膜内传导不改变同类型神经节细胞之间的相对发放时间，但增加了不同类型神经节细胞之间的发放时间差异。因此，最快的视网膜神经节细胞充当突触后神经元的新刺激的指示器。根据文献中的数据估计，视网膜外传导时间的变化不会补偿群体活动的视网膜内分散。
Visual stimuli elicit action potentials in tens of different retinal ganglion cells. Each ganglion cell type responds with a different latency to a given stimulus, thus transforming the high-dimensional input into a temporal neural code. The timing of the first spikes between different retinal projection neurons cells may further change along axonal transmission. The purpose of this study is to investigate if intraretinal conduction velocity leads to a synchronization or dispersion of the population signal leaving the eye. We ‘imaged’ the initiation and transmission of light-evoked action potentials along individual axons in the rabbit retina at micron-scale resolution using a high-density multi-transistor array. We measured unimodal conduction velocity distributions (1.3±0.3 m/sec, mean ± SD) for axonal populations at all retinal eccentricities with the exception of the central part that contains myelinated axons. The velocity variance within each piece of retina is caused by ganglion cell types that show narrower and slightly different average velocity tuning. Ganglion cells of the same type respond with similar latency to spatially homogenous stimuli and conduct with similar velocity. For ganglion cells of different type intraretinal conduction velocity and response latency to flashed stimuli are negatively correlated, indicating that differences in first spike timing increase (up to 10 msec). Similarly, the analysis of pair-wise correlated activity in response to white-noise stimuli reveals that conduction velocity and response latency are negatively correlated. Intraretinal conduction does not change the relative spike timing between ganglion cells of the same type but increases spike timing differences among ganglion cells of different type. The fastest retinal ganglion cells therefore act as indicators of new stimuli for postsynaptic neurons. The intraretinal dispersion of the population activity will not be compensated by variability in extraretinal conduction times, estimated from data in the literature.
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影响因子：
9.2
作者：
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通讯作者：
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作者：
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DOI：
10.1073/pnas.0900573106
发表时间：
2009-04-07
影响因子：
11.1
作者：
Jacobs, Adam L.;Fridman, Gene;Nirenberg, Sheila
通讯作者：
Nirenberg, Sheila