Excitatory and suppressive receptive field subunits in awake monkey primary visual cortex (V1)
Excitatory and suppressive receptive field subunits in awake monkey primary visual cortex (V1)
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DOI：
10.1073/pnas.0706938104
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发表时间：
2007-11-27
影响因子：
11.1
通讯作者：
Dan, Yang
中科院分区：
文献类型：
--
作者：
Chen, Xiaodong;Han, Feng;Dan, Yang
理解视觉加工的一个重要步骤是表征视觉通路每个阶段的神经元感受野（RF）。然而，在初级视觉皮层（V1）中的简单细胞之外的RF表征仍然是一个重大挑战。最近的应用尖峰触发的协方差（STC）分析，极大地促进了表征复杂的细胞RF在麻醉动物。在这里，我们将STC应用于清醒猴V1的RF表征。我们发现每个细胞最多有9个亚基，包括一个或两个标准模型所描述的主要兴奋性亚基，沿着其他贡献较弱的兴奋性和抑制性亚基。与优势亚基相比，非优势兴奋性亚基的取向和空间频率相似，但空间包络较大。它们有助于对刺激方向、位置和空间频率的微小变化的反应不变性。相反，抑制性亚基被调整到与兴奋性亚基不同的45度-90度的取向，这可能是交叉取向抑制的基础。总之，兴奋性和抑制性亚基形成一个紧凑的描述RF清醒的猴子V1，允许预测的反应，任意的视觉刺激。
An essential step in understanding visual processing is to characterize the neuronal receptive fields (RFs) at each stage of the visual pathway. However, RF characterization beyond simple cells in the primary visual cortex (V1) remains a major challenge. Recent application of spike-triggered covariance (STC) analysis has greatly facilitated characterization of complex cell RFs in anesthetized animals. Here we apply STC to RF characterization in awake monkey V1. We found up to nine subunits for each cell, including one or two dominant excitatory subunits as described by the standard model, along with additional excitatory and suppressive subunits with weaker contributions. Compared with the dominant subunits, the nondominant excitatory subunits prefer similar orientations and spatial frequencies but have larger spatial envelopes. They contribute to response invariance to small changes in stimulus orientation, position, and spatial frequency. In contrast, the suppressive subunits are tuned to orientations 45 degrees - 90 degrees different from the excitatory subunits, which may underlie cross-orientation suppression. Together, the excitatory and suppressive subunits form a compact description of RFs in awake monkey V1, allowing prediction of the responses to arbitrary visual stimuli.