In the vertebrate brain, sensory experience plays a crucial role in shaping thalamocortical connections for visual processing. However, it is still not clear how visual experience influences tissue homeostasis and neurogenesis in the developing thalamus. Here, we reported that the majority of SOX2-positive cells in the thalamus are differentiated neurons that receive visual inputs as early as stage 47 Xenopus. Visual deprivation (VD) for 2 days shifts the neurogenic balance toward proliferation at the expense of differentiation, which is accompanied by a reduction in nuclear-accumulated β-catenin in SOX2-positive neurons. The knockdown of β-catenin decreases the expression of SOX2 and increases the number of progenitor cells. Coimmunoprecipitation studies reveal the evolutionary conservation of strong interactions between β-catenin and SOX2. These findings indicate that β-catenin interacts with SOX2 to maintain homeostatic neurogenesis during thalamus development.

Recent studies show that the human adult visual system exhibits neural plasticity. For instance, short-term monocular deprivation shifts the eye dominance in favor of the deprived eye. This phenomenon is believed to occur in the primary visual cortex by reinstating neural plasticity. However, it is unknown whether the changes in eye dominance after monocularly depriving the visual input can also be induced by alternately depriving both eyes. In this study, we found no changes in binocular balance and interocular correlation sensitivity after a rapid (7 Hz), alternate and monocular deprivation for one hour in adults. Therefore, the effect of short-term monocular deprivation cannot seem to be emulated by alternately and rapidly depriving both eyes.Significance statementPrevious work has shown that short-term binocular function disruption, which its most extreme form is monocular deprivation, could induce neural plasticity in adult visual system. In this study, we found a balanced deprivation of binocular function could not induce a neuroplastic change in human adults. It appears that ocular dominance plasticity in human adults is unique in so far as it is only driven by an input imbalance not balanced deprivation of binocular function.

We aimed to explore whether motor function and activities of daily life (ADL) could be improved with the application of visual deprivation in two patients with Pusher syndrome complicated by hemispatial neglect after right basal ganglia stroke. We assessed two stroke patients suffering from severe motor disturbances, both tilting heavily to the left, with diagnoses of Pusher syndrome and left hemispatial neglect. Vision in the left eye was deprived using patches during clinical rehabilitation. Motor function promotion was confirmed using the Burke Lateropulsion Scale (BLS), Fugl-Meyer Balance Scale (FMBS), and Holden grade (HG), while the Barthel index (BI) assessed ADL immediately and 1 week after intervention. Both patients regained standing balance immediately using visual deprivation, as well as walking ability, although both scored 0 on the FMBS and HG. After 1 week of treatment, one patient increased to 11 and 3 on the FMBS and HG, respectively, while the BLS score decreased from 12 to 2, and the ADL increased from 23 to 70. The other patient demonstrated increases to 10 and 3 on the FMBS and HG, respectively, with the BLS decreasing from 13 to 3, and the ADL increasing from 25 to 60. Therefore, in the rehabilitation treatment of Pusher syndrome complicated by hemispatial neglect due to basal ganglia stroke, visual deprivation can significantly improve motor function and shorten the treatment course.

Can we recognize faces with zero experience on faces? This question is critical because it examines the role of experiences in the formation of domain-specific modules in the brain. Investigation with humans and non-human animals on this issue cannot easily dissociate the effect of the visual experience from that of the hardwired domain-specificity. Therefore, the present study built a model of selective deprivation of the experience on faces with a representative deep convolutional neural network, AlexNet, by removing all images containing faces from its training stimuli. This model did not show significant deficits in face categorization and discrimination, and face-selective modules automatically emerged. However, the deprivation reduced the domain-specificity of the face module. In sum, our study provides empirical evidence on the role of nature vs. nurture in developing the domain-specific modules that domain-specificity may evolve from non-specific experience without genetic predisposition, and is further fine-tuned by domain-specific experience.

Early visual deprivation is known to have profound consequences on the subsequent development of spatial visual processing. However, its impact on temporal processing is not well characterized. We have examined spatial and temporal contrast sensitivity functions following treatment for early and extended bilateral visual deprivation in fifteen children born with congenital cataracts in rural India. The results reveal a marked difference in post-treatment spatial and temporal sensitivities. Whereas spatial processing in newly sighted children is significantly impaired relative to age-matched controls, temporal processing exhibits remarkable resilience and is comparable to that in the control group. This difference in spatial and temporal outcomes is especially surprising given our computational analyses of video sequences which indicate a strong linkage between the spatial and temporal spectral content of natural visual inputs. We consider possible explanations for this discrepancy.

Sensory experience shapes what and how knowledge is stored in the brain-our knowledge about the color of roses depends in part on the activity of color-responsive neurons based on experiences of seeing roses. We compared the brain basis of color knowledge in congenitally (or early) blind individuals, whose color knowledge can only be obtained through language descriptions and/or cognitive inference, to that of sighted individuals whose color-knowledge benefits from both sensory experience and language. We found that some regions support color knowledge only in the sighted, whereas a region in the left dorsal anterior temporal lobe supports object-color knowledge in both the blind and sighted groups, indicating the existence of a sensory-independent knowledge coding system in both groups. Thus, there are (at least) two forms of object knowledge representations in the human brain: sensory-derived and language- and cognition-derived knowledge, supported by different brain systems.

Changes in the electrical activities of visual and auditory thalamic-cortical regions account for the cross-modal enhancement of auditory perception following visual deprivation, but the molecular regulatory factors mediating these changes remain elusive. In this study, we showed that the expression patterns of five glutamate receptor (GluR) subunits which involved in regulating the synaptic plasticity in mouse primary visual (V1) cortex and primary auditory (A1) cortex undergone elaborate modification with layer-specificity after visual deprivation using dark-exposure (DE). The expression levels of NR1 and NR2B were increased, and those of GluR1 and NR2B in the V1 cortex were decreased after DE. In the A1 cortex, the expression levels of NR1, NR2A and NR2B were increased, and the expression levels of GluR1 and GluR2 were decreased after DE. The altered expression levels of GluR subunits selectively happened in the different layers of V1 and A1 cortices. In addition, the expression level of GluR2 in lateral geniculate nucleus (LGN) was decreased. These results provide novel molecular clues for the plastic neural activity in visual and auditory centers in the absence of visual input, and hint the extensive refinement of intracortical circuits and thalamocortical feedback circuits underlying the multisensory cross-modal plasticity.

Color vision has been consistently shown to be unaffected in animals that are raised in dark or in color-deprived environments. However, there are only a few studies that directly addressed the effect of congenital visual deprivation in color perception in humans.
The goal of the current study was to assess the effect of congenital visual deprivation on color vision using a panel based color arrangement test.
We investigated the recovery of color vision using the Farnsworth D15 test in a group of individuals who had experienced visual deprivation since birth due to bilateral dense congenital cataracts before undergoing cataract-reversal surgery (Congenital cataract, CC, n = 12). In addition, we tested two groups of control participants: (1) individuals who had had non-dense congenital cataract or developed cataract later in their childhood (Developmental cataract, DC, n = 10), and (2) sighted controls with normal or corrected to normal vision (n = 14). Based on the methods proposed by Vingrys and King-Smith (1988), we derived the following metrics of color vision performance: (1) total error score, (2) confusion index, (3) confusion angle, and (4) selectivity index.
All of the measured indices of color vision performance were unaltered by a period of congenital visual deprivation.
Our results support the view that, development of visual functions such as color discrimination and color arrangement does not depend on typical visual experience during a sensitive phase in early childhood.

Loss of vision may enhance the capabilities of auditory perception, but the mechanisms mediating these changes remain elusive. Here, visual deprivation in rats resulted in altered oscillatory activities, which appeared to be the result of a common mechanism underlying neuronal assembly formation in visual and auditory centers. The power of high-frequency β and γ oscillations in V1 (the primary visual cortex) and β oscillations in the LGN (lateral geniculate nucleus) was increased after one week of visual deprivation. Meanwhile, the power of β oscillations in A1 (the primary auditory cortex) and the power of β and γ oscillations in the MGB (medial geniculate body) were also enhanced in the absence of visual input. Furthermore, nerve tracing revealed a bidirectional nerve fiber connection between V1 and A1 cortices, which might be involved in transmitting auditory information to the visual cortex, contributing to enhanced auditory perception after visual deprivation. These results may facilitate the better understanding of multisensory cross-modal plasticity.

Acupuncture therapy has a positive effect in the treatment of amblyopia. This article summarizes findings of the research on brain mechanisms underlying the regulatory effect of acupuncture on visual plasticity of amblyopia. In a multi-system and multi-level viewpoints, we elaborated brain mechanism underlying the regulatory effect of acupuncture on visual plasticity in amblyopia from the perspective of ultrastructure, plasticity, electrical activities, neural coding and visual microcirculation of the neurons of the visual cortex, and the targeting points from the visual center to the effector organ.