Department of Psychology, University of California , Los Angeles, California.
Department of Neurobiology, David Geffen School of Medicine, University of California , Los Angeles, California.
J Neurophysiol. 2018 Jul 1;120(1):274-280. doi: 10.1152/jn.00150.2018. Epub 2018 Apr 18.
Neurons in primary visual cortex are selective to the orientation and spatial frequency of sinusoidal gratings. In the classic model of cortical organization, a population of neurons responding to the same region of the visual field but tuned to all possible feature combinations provides a detailed representation of the local image. Such a functional module is assumed to be replicated across primary visual cortex to provide a uniform representation of the image across the entire visual field. In contrast, it has been hypothesized that the tiling properties of ON- and OFF-center receptive fields in the retina, largely mirrored in the geniculate, may constrain cortical tuning at each location in the visual field. This model predicts the existence of local biases in tuning that vary across the visual field and would prevent the cortex from developing a uniform, modular representation as postulated by the classic model. Here, we confirm the existence of local tuning biases in the primary visual cortex of the mouse, lending support to the notion that cortical tuning may be constrained by signals from the periphery. NEW & NOTEWORTHY Populations of cortical neurons responding to the same part of the visual field are shown to have similar tuning. Such local biases are consistent with the hypothesis that cortical tuning, in mouse primary visual cortex, is constrained by signals from the periphery.
初级视皮层中的神经元对正弦光栅的方向和空间频率具有选择性。在经典的皮层组织模型中，一群对同一视野区域但对所有可能特征组合都有反应的神经元提供了对局部图像的详细表示。假设这样的功能模块在初级视皮层中复制，以在整个视野中提供图像的均匀表示。相比之下，有人假设视网膜中 ON- 和 OFF- 中心感受野的平铺特性，在很大程度上反映在视丘中，可能会限制视野中每个位置的皮层调谐。该模型预测了调谐中的局部偏差的存在，这些偏差在整个视野中变化，并且会阻止皮层像经典模型所假设的那样发展出统一的、模块化的表示。在这里，我们证实了在鼠标的初级视皮层中存在局部调谐偏差，这支持了皮层调谐可能受到来自外围的信号限制的观点。新的和值得注意的是，对视觉场相同部分做出反应的皮层神经元群体显示出相似的调谐。这种局部偏差与这样的假设一致，即鼠标初级视皮层中的皮层调谐受到来自外围的信号的限制。
