Effects of muscarinic and nicotinic receptors on contextual modulation in macaque area V1

• Published in: Scientific reports Vol. 11; no. 1; pp. 8384 - 15
• Main Authors: Herrero, Jose L., Thiele, Alexander
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 16-04-2021; Nature Publishing Group; Nature Portfolio
• Subjects: 631/378/2613; 631/378/87; Acetylcholine receptors (muscarinic); Acetylcholine receptors (nicotinic); Animals; Contrast Sensitivity - drug effects; Contrast Sensitivity - physiology; Feedback; Humanities and Social Sciences; Macaca mulatta; Male; Mecamylamine; multidisciplinary; Muscarinic Antagonists - pharmacology; Neuromodulation; Neurons; Neurons - drug effects; Neurons - physiology; Nicotinic Antagonists - pharmacology; Photic Stimulation; Receptors, Muscarinic - chemistry; Receptors, Muscarinic - metabolism; Receptors, Nicotinic - chemistry; Receptors, Nicotinic - metabolism; Science; Science (multidisciplinary); Scopolamine; Thalamus; Visual cortex; Visual Cortex - drug effects; Visual Cortex - physiology
• ISSN: 2045-2322; 2045-2322
• 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.