Ahmadlou Mehran, Heimel J Alexander
Netherlands Institute for Neuroscience, an institute of the Royal Academy of Arts and Sciences, Cortical Structure &Function group, Meibergdreef 47, 1105 BA Amsterdam, The Netherlands.
Nat Commun. 2015 Apr 2;6:6773. doi: 10.1038/ncomms7773.
The superior colliculus is a layered structure important for body- and gaze-orienting responses. Its superficial layer is, next to the lateral geniculate nucleus, the second major target of retinal ganglion axons and is retinotopically organized. Here we show that in the mouse there is also a precise organization of orientation preference. In columns perpendicular to the tectal surface, neurons respond to the same visual location and prefer gratings of the same orientation. Calcium imaging and extracellular recording revealed that the preferred grating varies with retinotopic location, and is oriented parallel to the concentric circle around the centre of vision through the receptive field. This implies that not all orientations are equally represented across the visual field. This makes the superior colliculus different from visual cortex and unsuitable for translation-invariant object recognition and suggests that visual stimuli might have different behavioural consequences depending on their retinotopic location.
上丘是一个分层结构，对身体定向和注视定向反应很重要。其表层是继外侧膝状核之后视网膜神经节轴突的第二个主要靶点，并且具有视网膜拓扑组织。在这里我们表明，在小鼠中也存在精确的方向偏好组织。在垂直于顶盖表面的柱中，神经元对相同的视觉位置做出反应，并偏好相同方向的光栅。钙成像和细胞外记录显示，偏好的光栅随视网膜拓扑位置而变化，并且与通过感受野围绕视觉中心的同心圆平行排列。这意味着并非所有方向在整个视野中都有同等的代表性。这使得上丘不同于视觉皮层，不适合进行平移不变的物体识别，并表明视觉刺激可能因其视网膜拓扑位置而产生不同的行为后果。
