Feinstein Institute of Medical Research, New York, USA.
Biosciences Institute, Newcastle University, Henry Wellcome Building, Newcastle upon Tyne, NE2 4HH, UK.
Sci Rep. 2021 Apr 16;11(1):8384. doi: 10.1038/s41598-021-88044-7.
Context affects the salience and visibility of image elements in visual scenes. Collinear flankers can enhance or decrease the perceptual and neuronal sensitivity to flanked stimuli. These effects are mediated through lateral interactions between neurons in the primary visual cortex (area V1), in conjunction with feedback from higher visual areas. The strength of lateral interactions is affected by cholinergic neuromodulation. Blockade of muscarinic receptors should increase the strength of lateral intracortical interactions, while nicotinic blockade should reduce thalamocortical feed-forward drive. Here we test this proposal through local iontophoretic application of the muscarinic receptor antagonist scopolamine and the nicotinic receptor antagonist mecamylamine, while recording single cells in parafoveal representations in awake fixating macaque V1. Collinear flankers generally reduced neuronal contrast sensitivity. Muscarinic and nicotinic receptor blockade equally reduced neuronal contrast sensitivity. Contrary to our hypothesis, flanker interactions were not systematically affected by either receptor blockade.
上下文会影响视觉场景中图像元素的显著性和可见性。共线侧抑制可以增强或降低对侧翼刺激的感知和神经元敏感性。这些影响是通过初级视觉皮层（V1 区）神经元之间的侧向相互作用以及来自更高视觉区域的反馈来介导的。侧向相互作用的强度受胆碱能神经调制的影响。毒蕈碱受体阻断剂的阻断应该增加皮质内侧向相互作用的强度，而烟碱受体阻断剂的阻断应该减少丘脑皮质前馈驱动。在这里，我们通过局部离子电泳应用毒蕈碱受体拮抗剂东莨菪碱和烟碱受体拮抗剂美加明，同时在清醒注视猕猴 V1 的中央凹旁区域记录单个细胞，来验证这一假设。共线侧翼通常会降低神经元的对比度敏感性。毒蕈碱和烟碱受体阻断剂同样降低了神经元的对比度敏感性。与我们的假设相反，侧翼相互作用不受任何一种受体阻断剂的系统影响。
