1. GABAergic inhibition in the human visual cortex relates to eye dominance
- Author
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I. Betina Ip, Uzay E. Emir, Andrew Parker, Claudia Lunghi, Holly Bridge, Laboratoire des systèmes perceptifs (LSP), Département d'Etudes Cognitives - ENS Paris (DEC), École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS Paris), and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS) more...
- Subjects
Male ,Magnetic Resonance Spectroscopy ,genetic structures ,medicine.medical_treatment ,Striate cortex ,030218 nuclear medicine & medical imaging ,0302 clinical medicine ,GABAergic Neurons ,gamma-Aminobutyric Acid ,media_common ,Visual Cortex ,Vision, Binocular ,Multidisciplinary ,medicine.diagnostic_test ,Reciprocal inhibition ,Magnetic Resonance Imaging ,Dominance, Ocular ,Dominance (ethology) ,medicine.anatomical_structure ,Cerebral cortex ,Medicine ,Sensory processing ,Female ,Adult ,media_common.quotation_subject ,Science ,Biology ,Inhibitory postsynaptic potential ,Article ,Ocular dominance ,Young Adult ,03 medical and health sciences ,Perception ,medicine ,Humans ,Monocular ,[SCCO.NEUR]Cognitive science/Neuroscience ,Neural Inhibition ,eye diseases ,Oxygen ,Visual cortex ,sense organs ,Visual system ,Functional magnetic resonance imaging ,Neuroscience ,Binocular vision ,Photic Stimulation ,030217 neurology & neurosurgery - Abstract
Our binocular world is seamlessly assembled from two retinal images that remain segregated until the cerebral cortex. Despite the coherence of this input, there is often an imbalance between the strength of these connections in the brain. ‘Eye dominance’ provides a measure of the perceptual dominance of one eye over the other. Theoretical models suggest that eye dominance is related to reciprocal inhibition between monocular units in the primary visual cortex, the first location where the binocular input is combined. As the specific inhibitory interactions in the binocular visual system critically depend on the presence of visual input, we sought to test the role of inhibition by measuring the concentrations of inhibitory (GABA) neurotransmitters during monocular visual stimulation of the dominant and the non-dominant eye. GABA-levels were acquired in V1 using a combined functional magnetic resonance imaging (fMRI) and magnetic resonance spectroscopy (MRS) sequence on a 7-Tesla MRI scanner. Individuals with stronger eye dominance had a greater difference in GABAergic inhibition between the eyes. This relationship was present only when the visual system was actively processing sensory input and was not present at rest. We provide the first evidence that imbalances in GABA levels during ongoing sensory processing are related to eye dominance in the human visual cortex. This provides strong support to the view that intracortical inhibition underlies normal eye dominance.SIGNIFICANCE STATEMENTWhat we see is shaped by excitation and inhibition in our brain. We investigated how eye dominance, the perceptual preference of one eye’s input over the other, is related to levels of inhibitory neurotransmitter GABA during monocular visual stimulation. GABAergic inhibition is related to eye dominance, but only when the visual system is actively processing sensory input. This provides key support for the view that imbalances in visual competition that are observed in the normal visual system arise from an inability of GABA signalling to suppress the stronger sensory representation. more...
- Published
- 2021
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