Task-Dependent V1 Responses in Human Retinitis Pigmentosa

Masuda, Yoichiro; Horiguchi, Hiroshi; Dumoulin, Serge O.; Furuta, Ayumu; Miyauchi, Satoru; Nakadomari, Satoshi; Wandell, Brian A.

doi:10.1167/iovs.09-4775

Cited by 55 publications

(80 citation statements)

References 76 publications

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“…A cost-induced shift of cortical reorganization from earlier to later stages of visual processing would straightforwardly explain why reorganization in the form of cortical remapping appears to be absent in adult V1 (Sunness et al, 2004;Smirnakis et al, 2005;Wandell and Smirnakis, 2009;Baseler et al, 2011). The hypothesis is also consistent with the task-dependent differences in V1 activation between patients and controls reported by Masuda et al (2008Masuda et al ( , 2010, who reasoned that the task-dependent responses in the LPZ of V1 must reflect unmasked feedback signals from the extra-striate visual areas, rather than cortical reorganization at the level of V1.…”

supporting

confidence: 63%

“…However, abnormal activity in itself does not warrant the conclusion that cortical remapping has occurred (Masuda et al, 2008;Wandell and Smirnakis, 2009;Baseler et al, 2009;Masuda et al, 2010;Haak et al, 2014c field changes as controls with simulated lesions, indicating that these changes were caused by the absence of visual stimulation alone. Importantly, these voxels were found far into the LPZ, indicating that the receptive field changes could not be easily explained by measurement artifacts at the fringe of the LPZ (Haak et al, 2012;Binda et al, 2013).…”

mentioning

confidence: 88%

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Plasticity, and Its Limits, in Adult Human Primary Visual Cortex

2015

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Article:Haak, Koen V, Morland, Antony B orcid.org/0000-0002-6754-5545 and Engel, Stephen A (2015) Plasticity, and Its Limits, in Adult Human Primary Visual Cortex. Multisensory Research. 297-307. ISSN 2213-4808 https://doi.org/10.1163/22134808-00002496 eprints@whiterose.ac.uk https://eprints.whiterose.ac.uk/ Reuse Unless indicated otherwise, fulltext items are protected by copyright with all rights reserved. The copyright exception in section 29 of the Copyright, Designs and Patents Act 1988 allows the making of a single copy solely for the purpose of non-commercial research or private study within the limits of fair dealing. The publisher or other rights-holder may allow further reproduction and re-use of this version -refer to the White Rose Research Online record for this item. Where records identify the publisher as the copyright holder, users can verify any specific terms of use on the publisher's website. TakedownIf you consider content in White Rose Research Online to be in breach of UK law, please notify us by emailing eprints@whiterose.ac.uk including the URL of the record and the reason for the withdrawal request. Multisensory ResearchPlasticity, and its Limits, in Adult Human Primary Visual Cortex There is an ongoing debate about whether adult human primary visual cortex (V1) is capable of large-scale cortical reorganization in response to bilateral retinal lesions. Animal models suggest that the visual neural circuitry maintains some plasticity through adulthood, and there are also a few human imaging studies in support this notion. However, the interpretation of these data has been brought into question, because there are factors besides cortical reorganization that could also explain the results. Still, how reasonable would it be to accept that adult human V1 does not reorganize itself in the face of disease? Here, we discuss new evidence for the hypothesis that adult human V1 is not as capable of reorganization as in animals and juveniles, because in adult humans, cortical reorganization would come with costs that outweigh its benefits. These costs are likely functional and visible in recent experiments on adaptation a rapid, short-term form of neural plasticity where they prevent reorganization from being sustained over the long-term. Keywords AbstractThere is an ongoing debate about whether adult human primary visual cortex (V1) is capable of

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confidence: 63%

mentioning

confidence: 88%

Plasticity, and Its Limits, in Adult Human Primary Visual Cortex

2015

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“…However, although activation was located only in the left occipital cortex, it was more lateral and basal than expected. This may represent activation of association cortex processing inputs to primary visual cortex that were below the level of detection, or increased attention to the button press during the task (25,26). Alternatively, it could indicate plasticity of cortical neuronal connectivity due to the disease/treatment.…”

Section: Discussionmentioning

confidence: 99%

“…The presence of nystagmus in each patient may have influenced the fMRI results by dictating the amount of time the eye can fixate on a particular object. Alternatively, amblyopia, which is known to affect the degree of cortical activations (26), may have played a role in the level of improvement in the LCA patients. Interestingly, psychophysical testing of contrast sensitivity before and after treatment had not revealed changes in any of the subjects (16,17).…”

Section: Figurementioning

confidence: 99%

The human visual cortex responds to gene therapy–mediated recovery of retinal function

Ashtari¹,

Cyckowski²,

Monroe³

et al. 2011

J. Clin. Invest.

122

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Leber congenital amaurosis (LCA) is a rare degenerative eye disease, linked to mutations in at least 14 genes. A recent gene therapy trial in patients with LCA2, who have mutations in RPE65, demonstrated that subretinal injection of an adeno-associated virus (AAV) carrying the normal cDNA of that gene (AAV2-hRPE65v2) could markedly improve vision. However, it remains unclear how the visual cortex responds to recovery of retinal function after prolonged sensory deprivation. Here, 3 of the gene therapy trial subjects, treated at ages 8, 9, and 35 years, underwent functional MRI within 2 years of unilateral injection of AAV2-hRPE65v2. All subjects showed increased cortical activation in response to high-and medium-contrast stimuli after exposure to the treated compared with the untreated eye. Furthermore, we observed a correlation between the visual field maps and the distribution of cortical activations for the treated eyes. These data suggest that despite severe and long-term visual impairment, treated LCA2 patients have intact and responsive visual pathways. In addition, these data suggest that gene therapy resulted in not only sustained and improved visual ability, but also enhanced contrast sensitivity.

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“…Stimulating the occipital cortex of a patient blinded in adulthood by trauma to the optic nerves resulted in abnormal phosphene maps, also suggesting cortical remapping 17 . Despite these reports, the implication that remapping is responsible for the large-scale spread of activation within the lesion projection zone of patients with retinal lesions acquired in adulthood has been seriously questioned [18][19][20] .…”

Section: Introductionmentioning

confidence: 99%

Large-scale remapping of visual cortex is absent in adult humans with macular degeneration

et al. 2011

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International audienceThe occipital lobe contains a retinotopic representation of the visual field. The representation of the central retina in early visual areas (V1-3) is found at the occipital pole. When the central retina is lesioned in both eyes by macular degeneration, this region of visual cortex at the occipital pole is accordingly deprived of input. However, even when such lesions occur in adulthood, some visually driven activity in and around the occipital pole can be observed. It has been suggested that this activity is due to remapping of this area, so that it now responds to inputs from intact, peripheral retina. We evaluated whether or not remapping of visual cortex underlies this activity. Our fMRI results provide no evidence of remapping, questioning the contemporary view that early visual areas of the adult human brain have the capacity to reorganize extensively

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Task-Dependent V1 Responses in Human Retinitis Pigmentosa

Cited by 55 publications

References 76 publications

Plasticity, and Its Limits, in Adult Human Primary Visual Cortex

Plasticity, and Its Limits, in Adult Human Primary Visual Cortex

The human visual cortex responds to gene therapy–mediated recovery of retinal function

Large-scale remapping of visual cortex is absent in adult humans with macular degeneration

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