小柯机器人

空间连接性与视觉皮层中的方向选择性一致
2020-11-15 00:26

英国伦敦大学学院L. Federico Rossi等研究人员发现,空间连接性与视觉皮层中的方向选择性一致。相关论文于2020年11月11日在线发表于国际学术期刊《自然》。

研究人员发现,通过遵循精确的空间模式,与第2/3层神经元的兴奋性和抑制性皮质内连接符合其选择性。研究人员使用狂犬病示踪标记和功能成像到小鼠视觉皮层2/3层的各个锥体神经元的兴奋性和抑制性输入。突触前兴奋性神经元跨越第2/3和4层,并与突触后神经元的首选方向同轴分布,这有利于与其首选方向相反的区域。
 
相比之下,突触前抑制神经元驻留在第2/3层内,并且位于突触后神经元附近以及其首选方向之前。突触后神经元的方向选择性与突触前神经元的选择性无关,但与兴奋性和抑制性突触前集合之间的空间位移相关。相似的不对称连接性在视网膜中建立方向选择性。这表明该回路模体在感觉处理中可能是经典的。
 
据悉,神经元反应的选择性来自兴奋性和抑制性连接的结构。在初级视觉皮层中,第2/3层神经元对刺激方向和方向的选择性被认为是由皮质内输入引起的,该输入具有类似的选择性。但是,神经元的兴奋性输入可能具有不同的刺激偏好,而抑制性输入可能是混杂的和非选择性的。
 
附:英文原文

Title: Spatial connectivity matches direction selectivity in visual cortex

Author: L. Federico Rossi, Kenneth D. Harris, Matteo Carandini

Issue&Volume: 2020-11-11

Abstract: The selectivity of neuronal responses arises from the architecture of excitatory and inhibitory connections. In the primary visual cortex, the selectivity of a neuron in layer 2/3 for stimulus orientation and direction is thought to arise from intracortical inputs that are similarly selective1,2,3,4,5,6,7,8. However, the excitatory inputs of a neuron can have diverse stimulus preferences1,2,3,4,6,7,9, and inhibitory inputs can be promiscuous10 and unselective11. Here we show that the excitatory and inhibitory intracortical connections to a layer 2/3 neuron accord with its selectivity by obeying precise spatial patterns. We used rabies tracing1,12 to label and functionally image the excitatory and inhibitory inputs to individual pyramidal neurons of layer 2/3 of the mouse visual cortex. Presynaptic excitatory neurons spanned layers 2/3 and 4 and were distributed coaxial to the preferred orientation of the postsynaptic neuron, favouring the region opposite to its preferred direction. By contrast, presynaptic inhibitory neurons resided within layer 2/3 and favoured locations near the postsynaptic neuron and ahead of its preferred direction. The direction selectivity of a postsynaptic neuron was unrelated to the selectivity of presynaptic neurons, but correlated with the spatial displacement between excitatory and inhibitory presynaptic ensembles. Similar asymmetric connectivity establishes direction selectivity in the retina13,14,15,16,17. This suggests that this circuit motif might be canonical in sensory processing.

DOI: 10.1038/s41586-020-2894-4

Source: https://www.nature.com/articles/s41586-020-2894-4

Nature:《自然》,创刊于1869年。隶属于施普林格·自然出版集团,最新IF:69.504
官方网址:http://www.nature.com/
投稿链接:http://www.nature.com/authors/submit_manuscript.html


本期文章:《自然》:Online/在线发表

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