Long term cortical plasticity in visual retinotopic areas in humans with silent retinal ganglion cell loss

d’Almeida, Otília C.; Mateus, Catarina; Reis, Aldina; Grazina, Manuela; Castelo‐Branco, Miguel

doi:10.1016/j.neuroimage.2013.05.032

Cited by 26 publications

(31 citation statements)

References 38 publications

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“…Young adult carriers of a mitochondrial DNA mutation causing Leber hereditary optic neuropathy have a loss of macular retinal ganglion cells and thicker visual cortex gray matter [68]. In contrast, older people with progressive retinal damage from glaucoma or macular degeneration have thinning in the corresponding eccentric locations of visual cortex [69–72].…”

Section: Discussionmentioning

confidence: 99%

Patterns of Individual Variation in Visual Pathway Structure and Function in the Sighted and Blind

et al. 2016

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Many structural and functional brain alterations accompany blindness, with substantial individual variation in these effects. In normally sighted people, there is correlated individual variation in some visual pathway structures. Here we examined if the changes in brain anatomy produced by blindness alter the patterns of anatomical variation found in the sighted. We derived eight measures of central visual pathway anatomy from a structural image of the brain from 59 sighted and 53 blind people. These measures showed highly significant differences in mean size between the sighted and blind cohorts. When we examined the measurements across individuals within each group we found three clusters of correlated variation, with V1 surface area and pericalcarine volume linked, and independent of the thickness of V1 cortex. These two clusters were in turn relatively independent of the volumes of the optic chiasm and lateral geniculate nucleus. This same pattern of variation in visual pathway anatomy was found in the sighted and the blind. Anatomical changes within these clusters were graded by the timing of onset of blindness, with those subjects with a post-natal onset of blindness having alterations in brain anatomy that were intermediate to those seen in the sighted and congenitally blind. Many of the blind and sighted subjects also contributed functional MRI measures of cross-modal responses within visual cortex, and a diffusion tensor imaging measure of fractional anisotropy within the optic radiations and the splenium of the corpus callosum. We again found group differences between the blind and sighted in these measures. The previously identified clusters of anatomical variation were also found to be differentially related to these additional measures: across subjects, V1 cortical thickness was related to cross-modal activation, and the volume of the optic chiasm and lateral geniculate was related to fractional anisotropy in the visual pathway. Our findings show that several of the structural and functional effects of blindness may be reduced to a smaller set of dimensions. It also seems that the changes in the brain that accompany blindness are on a continuum with normal variation found in the sighted.

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Section: Discussionmentioning

confidence: 99%

Patterns of Individual Variation in Visual Pathway Structure and Function in the Sighted and Blind

et al. 2016

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“…Anatomical volumes were re-oriented in relation to AC–PC plane and transformed to Talairach (TAL) coordinate system. Afterwards, the cerebral cortex was segmented into the cerebral spinal fluid, gray matter, and white matter using automatic segmentation routines in order to create inflated mesh representations of each hemisphere (d'Almeida et al, 2013). …”

Section: Methodsmentioning

confidence: 99%

“…In this way, the LPZ corresponds to the retinal scotomata in RP patients and the FPZ corresponds to the spared retina. Cortical thickness was calculated on the V1 regions using the standard procedure of BrainVoyager [see (d'Almeida et al, 2013) for a complete description]. To allow an accurate segmentation of white matter–gray matter and gray matter–cerebral spinal fluid boundary, TAL anatomical data were converted to high-resolution 0.5 × 0.5 × 0.5 mm 3 .…”

Section: Methodsmentioning

confidence: 99%

Primary visual cortical remapping in patients with inherited peripheral retinal degeneration

Ferreira

Pereira

Quendera

et al. 2017

NeuroImage: Clinical

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Human studies addressing the long-term effects of peripheral retinal degeneration on visual cortical function and structure are scarce. Here we investigated this question in patients with Retinitis Pigmentosa (RP), a genetic condition leading to peripheral visual degeneration. We acquired functional and anatomical magnetic resonance data from thirteen patients with different levels of visual loss and twenty-two healthy participants to study primary (V1) visual cortical retinotopic remapping and cortical thickness. We identified systematic visual field remapping in the absence of structural changes in the primary visual cortex of RP patients. Remapping consisted in a retinotopic eccentricity shift of central retinal inputs to more peripheral locations in V1. Importantly, this was associated with changes in visual experience, as assessed by the extent of the visual loss, with more constricted visual fields resulting in larger remapping. This pattern of remapping is consistent with expansion or shifting of neuronal receptive fields into the cortical regions with reduced retinal input. These data provide evidence for functional changes in V1 that are dependent on the magnitude of peripheral visual loss in RP, which may be explained by rapid cortical adaptation mechanisms or long-term cortical reorganization. This study highlights the importance of analyzing the retinal determinants of brain functional and structural alterations for future visual restoration approaches.

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“…However, each year, millions of infants worldwide suffer from visual deprivation. These populations face the risk of irreversible amblyopia and numerous vision impairments [34][35][36]. Thus, it is important to investigate the mechanisms of environmental regulation of visual system development and its experience-dependent plasticity, which may provide further evidence to develop a comprehensive method for assessing the visual recovery potential in blind children.…”

Section: Discussionmentioning

confidence: 99%

“…Previous studies have shown that the axial overgrowth and myopia caused by visual form deprivation can be manipulated by altering peripheral retinal defocus [42]. In addition, early retinal changes are reflected in retinotopically specific plasticity, which can be assessed by visual cortical thickness [34,43]. Both neurochemical and immunocytochemical experiments in chickens and monkeys suggest that definable retinal neurons participate in the regulatory pathway controlling eye growth [41].…”

Section: Discussionmentioning

confidence: 99%

Dynamic response to initial stage blindness in visual system development

et al. 2017

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Correspondence: Haotian Lin (gddlht@aliyun.com)Sensitive periods and experience-dependent plasticity have become core issues in visual system development. Converging evidence indicates that visual experience is an indispensable factor in establishing mature visual system circuitry during sensitive periods and the visual system exhibits substantial plasticity while facing deprivation. The mechanisms that underlie the environmental regulation of visual system development and plasticity are of great interest but need further exploration. Here, we investigated a unique sample of human infants who experienced initial stage blindness (beginning at birth and lasting for 2-8 months) before the removal of bilateral cataracts. Retinal thickness (RT), axial length (AL), refractive status, visual grating acuity and genetic integrity were recorded during the preoperative period or at surgery and then during follow-up. The results showed that the development of the retina is malleable and associated with external environmental influences. Our work supported that the retina might play critical roles in the development of the experience-dependent visual system and its malleability might partly contribute to the sensitive period plasticity.

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Long term cortical plasticity in visual retinotopic areas in humans with silent retinal ganglion cell loss

Cited by 26 publications

References 38 publications

Patterns of Individual Variation in Visual Pathway Structure and Function in the Sighted and Blind

Patterns of Individual Variation in Visual Pathway Structure and Function in the Sighted and Blind

Primary visual cortical remapping in patients with inherited peripheral retinal degeneration

Dynamic response to initial stage blindness in visual system development

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