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Mukerji A, Byrne KN, Yang E, Levi DM, Silver MA. Visual cortical γ-aminobutyric acid and perceptual suppression in amblyopia. Front Hum Neurosci 2022; 16:949395. [PMID: 36118971 PMCID: PMC9479630 DOI: 10.3389/fnhum.2022.949395] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2022] [Accepted: 08/17/2022] [Indexed: 01/23/2023] Open
Abstract
In amblyopia, abnormal visual experience during development leads to an enduring loss of visual acuity in adulthood. Physiological studies in animal models suggest that intracortical GABAergic inhibition may mediate visual deficits in amblyopia. To better understand the relationship between visual cortical γ-aminobutyric acid (GABA) and perceptual suppression in persons with amblyopia (PWA), we employed magnetic resonance spectroscopy (MRS) to quantify GABA levels in both PWA and normally-sighted persons (NSP). In the same individuals, we obtained psychophysical measures of perceptual suppression for a variety of ocular configurations. In PWA, we found a robust negative correlation between the depth of amblyopia (the difference in visual acuity between the amblyopic and non-amblyopic eyes) and GABA concentration that was specific to visual cortex and was not observed in a sensorimotor cortical control region. Moreover, lower levels of visual cortical GABA were associated with weaker perceptual suppression of the fellow eye by the amblyopic eye and stronger suppression of the amblyopic eye by the fellow eye. Taken together, our findings provide evidence that intracortical GABAergic inhibition is an important component of the pathology of human amblyopia and suggest possible therapeutic interventions to restore vision in the amblyopic eye through enhancement of visual cortical GABAergic signaling in PWA.
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Affiliation(s)
- Arjun Mukerji
- Helen Wills Neuroscience Institute, University of California, Berkeley, Berkeley, CA, United States,Henry H. Wheeler, Jr. Brain Imaging Center, University of California, Berkeley, Berkeley, CA, United States
| | - Kelly N. Byrne
- Henry H. Wheeler, Jr. Brain Imaging Center, University of California, Berkeley, Berkeley, CA, United States,Vision Science Graduate Group, University of California, Berkeley, Berkeley, CA, United States,School of Optometry, University of California, Berkeley, Berkeley, CA, United States
| | - Eunice Yang
- Henry H. Wheeler, Jr. Brain Imaging Center, University of California, Berkeley, Berkeley, CA, United States,School of Optometry, University of California, Berkeley, Berkeley, CA, United States
| | - Dennis M. Levi
- Helen Wills Neuroscience Institute, University of California, Berkeley, Berkeley, CA, United States,Henry H. Wheeler, Jr. Brain Imaging Center, University of California, Berkeley, Berkeley, CA, United States,Vision Science Graduate Group, University of California, Berkeley, Berkeley, CA, United States,School of Optometry, University of California, Berkeley, Berkeley, CA, United States
| | - Michael A. Silver
- Helen Wills Neuroscience Institute, University of California, Berkeley, Berkeley, CA, United States,Henry H. Wheeler, Jr. Brain Imaging Center, University of California, Berkeley, Berkeley, CA, United States,Vision Science Graduate Group, University of California, Berkeley, Berkeley, CA, United States,School of Optometry, University of California, Berkeley, Berkeley, CA, United States,*Correspondence: Michael A. Silver,
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