Color vision, initiated from the cone photoreceptors, is essential for fish to obtain environmental information. Although the visual impairment of triazine herbicide prometryn has been reported, data on the effect of herbicide such as prometryn on natural color sensitivity of fish is scarce. Here, zebrafish were exposed to prometryn (0, 1, 10, and 100 μg/L) from 2 h post-fertilization to 160 days post-fertilization, to explore the effect and underlying mechanism of prometryn on color perception. The results indicated that 10 and 100 μg/L prometryn shortened the height of red-green cone cells, and down-regulated expression of genes involved in light transduction pathways (arr3a, pde6h) and visual cycle (lrata, rpe65a); meanwhile, 1 μg/L prometryn increased all-trans-retinoic acid levels in zebrafish eyes, and up-regulated the expression of genes involved in retinoid metabolism (rdh10b, aldh1a2, cyp26a1), finally leading to weakened red and green color perception of female zebrafish. This study first clarified how herbicide such as prometryn affected color vision of a freshwater fish after a long-term exposure from both morphological and functional disruption, and its hazard on color vision mediated-ecologically relevant tasks should not be ignored.

Vision plays a major role in perceiving external stimuli and information in our daily lives. The neural mechanism of color vision is complicated, involving the co-ordinated functions of a variety of cells, such as retinal cells and lateral geniculate nucleus cells, as well as multiple levels of the visual cortex. In this work, we reviewed the history of experimental and theoretical studies on this issue, from the fundamental functions of the individual cells of the visual system to the coding in the transmission of neural signals and sophisticated brain processes at different levels. We discuss various hypotheses, models, and theories related to the color vision mechanism and present some suggestions for developing novel implanted devices that may help restore color vision in visually impaired people or introduce artificial color vision to those who need it.

OBJECTIVE: To examine relationships between visual function (ie, contrast sensitivity, visual field, color vision, and motion perception) and cognitive impairment, including any definition of \"cognitive impairment,\" mild cognitive impairment, or dementia.
METHODS: Systematic review and meta-analyses.
METHODS: Any settings; participants with (cases) or without (controls) cognitive impairment.
METHODS: We searched 4 databases (to January 2024) and included published studies that compared visual function between cases and controls. Standardized mean differences (SMD) with 95% CIs were calculated where data were available. Data were sufficient for meta-analyses when cases were people with dementia. The Joanna Briggs Institute checklists were used for quality assessment.
RESULTS: Fifty-one studies/69 reports were included. Cross-sectional evidence shows that people with dementia had worse contrast sensitivity function and color vision than controls: measured by contrast sensitivity (log units) on letter charts, SMD -1.22 (95% CI -1.98, -0.47), or at varied spatial frequencies, -0.92 (-1.28, -0.57); and by pseudoisochromatic plates, -1.04 (-1.59, -0.49); color arrangement, -1.30 (-2.31, -0.29); or matching tests, -0.51 (-0.78, -0.24). They also performed more poorly on tests of motion perception, -1.20 (-1.73, -0.67), and visual field: mean deviation, -0.87 (-1.29, -0.46), and pattern standard deviation, -0.69 (-1.24, -0.15). Results were similar when cases were limited to participants with clinically diagnosed Alzheimer disease. Sources of bias included lack of clarity on study populations or settings and definitions of cognitive impairment. The 2 included longitudinal studies with follow-ups of approximately 10 years were of good quality but reported inconsistent results.
CONCLUSIONS: In the lack of longitudinal data, cross-sectional studies indicate that individuals with cognitive impairment have poorer visual function than those with normal cognition. Additional longitudinal data are needed to understand whether poor visual function precedes cognitive impairment and the most relevant aspects of visual function, dementia pathologies, and domains of cognition.

暂无摘要。

In insects, vision is crucial in finding host plants, but its role in nocturnal insects is largely unknown. Vision involves responses to specific spectra of photon wavelengths and opsins plays an important role in this process. Long-wavelength sensitive opsin (LW opsin) and blue-sensitive opsin (BL opsin) are main visual opsin proteins and play important in behavior regulation.We used CRISPR/Cas9 technology to mutate the long-wavelength-sensitive and blue wavelength-sensitive genes and explored the role of vision in the nocturnal invasive pest Tuta absoluta. Light wave experiments revealed that LW2(-/-) and BL(-/-) mutants showed abnormal wavelength tropism. Both LW2 and BL mutations affected the preference of T. absoluta for the green environment. Mutations in LW2 and BL are necessary to inhibit visual attraction. The elimination of LW2 and BL affected the preference of leaf moths for green plants, and mutations in both induced a preference in moths for white plants. Behavioral changes resulting from LW2(-/-) and BL(-/-) mutants were not affected by sense of smell, further supporting the regulatory role of vision in insect behavior. To the best of our knowledge, this is the first study to reveal that vision, not smell, plays an important role in the host-seeking behavior of nocturnal insects at night, of which LW2 and BL opsins are key regulatory factors. These study findings will drive the development of the \"vision-ecology\" theory.

Egg-laying mammals (monotremes) are considered \"primitive\" due to traits such as oviparity, cloaca, and incomplete homeothermy, all of which they share with reptiles. Two groups of monotremes, the terrestrial echidna (Tachyglossidae) and semiaquatic platypus (Ornithorhynchidae), have evolved highly divergent characters since their emergence in the Cenozoic era. These evolutionary differences, notably including distinct electrosensory and chemosensory systems, result from adaptations to species-specific habitat conditions. To date, very few studies have examined the visual adaptation of echidna and platypus. In the present study, we show that echidna and platypus have different light absorption spectra in their dichromatic visual sensory systems at the molecular level. We analyzed absorption spectra of monotreme color opsins, long-wavelength sensitive opsin (LWS) and short-wavelength sensitive opsin 2 (SWS2). The wavelength of maximum absorbance (λmax) in LWS was 570.2 in short-beaked echidna (Tachyglossus aculeatus) and 560.6 nm in platypus (Ornithorhynchus anatinus); in SWS2, λmax was 451.7 and 442.6 nm, respectively. Thus, the spectral range in echidna color vision is ~ 10 nm longer overall than in platypus. Natural selection analysis showed that the molecular evolution of monotreme color opsins is generally functionally conserved, suggesting that these taxa rely on species-specific color vision. In order to understand the usage of color vision in monotremes, we made 24-h behavioral observations of captive echidnas at warm temperatures and analyzed the resultant ethograms. Echidnas showed cathemeral activity and various behavioral repertoires such as feeding, traveling, digging, and self-grooming without light/dark environment selectivity. Halting (careful) behavior is more frequent in dark conditions, which suggests that echidnas may be more dependent on vision during the day and olfaction at night. Color vision functions have contributed to dynamic adaptations and dramatic ecological changes during the ~ 60 million years of divergent monotreme evolution. The ethogram of various day and night behaviors in captive echidnas also contributes information relevant to habitat conservation and animal welfare in this iconic species, which is locally endangered.

Visual perception plays a crucial role in foraging, avoiding predators, mate selection, and communication. The regulation of color vision is largely dependent on opsin, which is the first step in the formation of the visual transduction cascade in photoreceptor cells. Short-wave-sensitive 1 (sws1) is a visual pigment that mediates short-wavelength light transduction in vertebrates. The depletion of sws1 resulted in increased M-opsin in mice. However, there is still no report on the visual function of sws1 in teleost fish. Here, we constructed the sws1 knockout medaka using CRISPR/Cas9 technology. The 6 dph (days post-hatching) medaka sws1-/- larvae exhibited significantly decreased food intake and total length at the first feeding stage, and the mRNA levels of orexigenic genes (npy and agrp) were significantly upregulated after feeding. The swimming speed was significantly reduced during the period of dark-light transition stimulation in the sws1-mutant larvae. Histological analysis showed that the thickness of the lens was reduced, whereas the thickness of the ganglion cell layer (GCL) was significantly increased in sws1-/- medaka larvae. Additionally, the deletion of sws1 decreased the mRNA levels of genes involved in phototransduction (gnb3b, grk7a, grk7b, and pde6c). We also observed increased retinal cell apoptosis and oxidative stress in sws1 knockout medaka larvae. Collectively, these results suggest that sws1 deficiency in medaka larvae may impair visual function and cause retinal cell apoptosis, which is associated with the downregulation of photoconduction expression and oxidative stress.

The cone photoreceptors in our eyes selectively transduce the natural light into spiking representations, which endows the brain with high energy-efficiency color vision. However, the cone-like device with color-selectivity and spike-encoding capability remains challenging. Here, we propose a metal oxide-based vertically integrated spiking cone photoreceptor array, which can directly transduce persistent lights into spike trains at a certain rate according to the input wavelengths. Such spiking cone photoreceptors have an ultralow power consumption of less than 400 picowatts per spike in visible light, which is very close to biological cones. In this work, lights with three wavelengths were exploited as pseudo-three-primary colors to form \'colorful\' images for recognition tasks, and the device with the ability to discriminate mixed colors shows better accuracy. Our results would enable hardware spiking neural networks with biologically plausible visual perception and provide great potential for the development of dynamic vision sensors.

The ARR3 gene, also known as cone arrestin, belongs to the arrestin family and is expressed in cone cells, inactivating phosphorylated-opsins and preventing cone signals. Variants of ARR3 reportedly cause X-linked dominant female-limited early-onset (age < 7 years old) high myopia (< - 6D). Here, we reveal a new mutation (c.228T>A, p.Tyr76*) in ARR3 gene that can cause early-onset high myopia (eoHM) limited to female carriers. Protan/deutan color vision defects were also found in family members, affecting both genders. Using ten years of clinical follow-up data, we identified gradually worsening cone dysfunction/color vision as a key feature among affected individuals. We present a hypothesis that higher visual contrast due to the mosaic of mutated ARR3 expression in cones contributes to the development of myopia in female carriers.

Retinitis pigmentosa (RP) is an ocular disease characterized by the loss of night vision, followed by the loss of daylight vision. Daylight vision is initiated in the retina by cone photoreceptors, which are gradually lost in RP, often as bystanders in a disease process that initiates in their neighboring rod photoreceptors. Using physiological assays, we investigated the timing of cone electroretinogram (ERG) decline in RP mouse models. A correlation between the time of loss of the cone ERG and the loss of rods was found. To investigate a potential role of the visual chromophore supply in this loss, mouse mutants with alterations in the regeneration of the retinal chromophore, 11-cis retinal, were examined. Reducing chromophore supply via mutations in Rlbp1 or Rpe65 resulted in greater cone function and survival in a RP mouse model. Conversely, overexpression of Rpe65 and Lrat, genes that can drive the regeneration of the chromophore, led to greater cone degeneration. These data suggest that abnormally high chromophore supply to cones upon the loss of rods is toxic to cones, and that a potential therapy in at least some forms of RP is to slow the turnover and/or reduce the level of visual chromophore in the retina.