Visual Response Properties of V1 Neurons Projecting to V2 in Macaque
Visual Response Properties of V1 Neurons Projecting to V2 in Macaque
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DOI：
10.1523/jneurosci.2753-13.2013
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发表时间：
2013-10-16
影响因子：
5.3
通讯作者：
Movshon, J. Anthony
中科院分区：
文献类型：
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作者：
El-Shamayleh, Yasmine;Kumbhani, Romesh D.;Movshon, J. Anthony
灵长类动物大脑皮层的视觉区V2从V1区接收最大的投影。V2被认为使用其条纹输入作为计算的基础，这些计算对视觉形式处理很重要，例如信号角度，物体边界，虚幻轮廓和相对双眼视差。然而，目前还不清楚这些刺激属性的选择性如何出现在V2中，部分原因是输入的功能属性是未知的。我们使用逆向电刺激来识别直接投射到V2的V1神经元（记录的所有V1神经元的10%），并表征其电和视觉反应。V2投射神经元集中在纹状体皮层的浅层和中层，与已知的皮质-皮质回路解剖结构一致。大多数是快速传导和时间精确的电反应，并广泛的尖峰波形与锥体规则尖峰兴奋性神经元一致。总的来说，投射神经元的功能是多样的。然而，大多数，调整方向和双眼视差，并强烈抑制大的刺激。投射神经元包括对空间相位具有选择性和不变性的神经元，它们的比例大致相等。在浅层发现的投射神经元有较长的传导时间，更广泛的尖峰波形，更响应于彩色刺激;那些发现在中间层的运动方向和双眼视差更强的选择性。总的来说，这些响应属性可以很好地适合于在V2中和超过V2生成复杂特征选择性。
Visual area V2 of the primate cortex receives the largest projection from area V1. V2 is thought to use its striate inputs as the basis for computations that are important for visual form processing, such as signaling angles, object borders, illusory contours, and relative binocular disparity. However, it remains unclear how selectivity for these stimulus properties emerges in V2, in part because the functional properties of the inputs are unknown. We used antidromic electrical stimulation to identify V1 neurons that project directly to V2 (10% of all V1 neurons recorded) and characterized their electrical and visual responses. V2-projecting neurons were concentrated in the superficial and middle layers of striate cortex, consistent with the known anatomy of this cortico-cortical circuit. Most were fast conducting and temporally precise in their electrical responses, and had broad spike waveforms consistent with pyramidal regular-spiking excitatory neurons. Overall, projection neurons were functionally diverse. Most, however, were tuned for orientation and binocular disparity and were strongly suppressed by large stimuli. Projection neurons included those selective and invariant to spatial phase, with roughly equal proportions. Projection neurons found in superficial layers had longer conduction times, broader spike waveforms, and were more responsive to chromatic stimuli; those found in middle layers were more strongly selective for motion direction and binocular disparity. Collectively, these response properties may be well suited for generating complex feature selectivity in and beyond V2.