scholarly journals Retinal specializations to a micro-predatory and crypto-benthic life-style in the Mediterranean triplefin blenny Tripterygion delaisi

2017 ◽  
Author(s):  
Roland Fritsch ◽  
Shaun P. Collin ◽  
Nico K. Michiels
Keyword(s):  
Visual Field ◽  
Ganglion Cell ◽  
Cross Sections ◽  
Ganglion Cells ◽  
Average Density ◽  
Resolving Power ◽  
Retinal Ganglion ◽  
Vast Number ◽  
The Mediterranean ◽  
Tripterygion Delaisi

AbstractThe environment and lifestyle of a species are known to exert selective pressure on the visual system, often demonstrating a tight link between visual morphology and ecology. Many studies have predicted the visual requirements of a species by examining the anatomical features of the eye. However, among the vast number of studies on visual specializations in aquatic animals, only a few have focused on small benthic fishes that occupy a heterogeneous and spatially complex visual environment. This study investigates the general retinal anatomy including the topography of both the photoreceptor and ganglion cell populations and estimates the spatial resolving power of the eye of the Mediterranean triplefin Tripterygion delaisi. Retinal wholemounts were prepared to systematically and quantitatively analyze photoreceptor and retinal ganglion cell densities using design-based stereology. To further examine the retinal structure, we also used magnetic resonance imaging and histological examination of retinal cross sections. Observations of the triplefin's eyes revealed them to be highly mobile, allowing them to view the surroundings without body movements. A rostral aphakic gap and the elliptical shape of the eye extend its visual field rostrally and allow for a rostro-caudal accommodatory axis, enabling this species to focus on prey at close range. Single and twin cones dominate the retina and are consistently arranged in one of two regular patterns, which may enhance motion detection and color vision. The retina features a prominent, dorso-temporal, convexiclivate fovea with an average density of 104,400 double and 30,800 single cones per mm2, and 81,000 retinal ganglion cells per mm2. Based on photoreceptor spacing, spatial resolving power was calculated to be between 6.7 and 9.0 cycles per degree. Location and resolving power of the fovea would benefit the detection and identification of small prey in the lower frontal region of the visual field.

The number, morphology, and distribution of retinal ganglion cells and optic axons in the Australian lungfishNeoceratodus forsteri(Krefft 1870)

2006 ◽  
Vol 23 (2) ◽  
pp. 257-273 ◽  
Author(s):  
HELENA J. BAILES ◽  
ANN E.O. TREZISE ◽  
SHAUN P. COLLIN
Keyword(s):  
Optic Nerve ◽  
Ganglion Cell ◽  
Retinal Ganglion Cells ◽  
Ganglion Cell Layer ◽  
Ganglion Cells ◽  
Cell Layer ◽  
Amacrine Cells ◽  
Resolving Power ◽  
Retinal Ganglion ◽  
Retrograde Labelling

Australian lungfishNeoceratodus forsterimay be the closest living relative to the first tetrapods and yet little is known about their retinal ganglion cells. This study reveals that lungfish possess a heterogeneous population of ganglion cells distributed in a horizontal streak across the retinal meridian, which is formed early in development and maintained through to adult stages. The number and complement of both ganglion cells and a population of putative amacrine cells within the ganglion cell layer are examined using retrograde labelling from the optic nerve and transmission electron-microscopic analysis of axons within the optic nerve. At least four types of retinal ganglion cells are present and lie predominantly within a thin ganglion cell layer, although two subpopulations are identified, one within the inner plexiform and the other within the inner nuclear layer. A subpopulation of retinal ganglion cells comprising up to 7% of the total population are significantly larger (>400 μm2) and are characterized as giant or alpha-like cells. Up to 44% of cells within the retinal ganglion cell layer represent a population of presumed amacrine cells. The optic nerve is heavily fasciculated and the proportion of myelinated axons increases with body length from 17% in subadults to 74% in adults. Spatial resolving power, based on ganglion cell spacing, is low (1.6–1.9 cycles deg−1,n= 2) and does not significantly increase with growth. This represents the first detailed study of retinal ganglion cells in sarcopterygian fish, and reveals that, despite variation amongst animal groups, trends in ganglion cell density distribution and characteristics of cell types were defined early in vertebrate evolution.

The Topographic Organization of Retinal Ganglion Cell Density and Spatial Resolving Power in an Unusual Arboreal and Slow-Moving Strepsirhine Primate, the Potto (Perodicticus potto)

2016 ◽  
Vol 87 (1) ◽  
pp. 4-18 ◽  
Author(s):  
João Paulo Coimbra ◽  
Consolate Kaswera-Kyamakya ◽  
Emmanuel Gilissen ◽  
Paul R. Manger ◽  
Shaun P. Collin
Keyword(s):  
Ganglion Cell ◽  
Cell Density ◽  
Retinal Ganglion Cells ◽  
Spatial Resolution ◽  
Ganglion Cells ◽  
Resolving Power ◽  
Retinal Ganglion ◽  
Upper Limits ◽  
Slow Moving ◽  
Topographic Distribution

The potto (Perodicticus potto) is an arboreal strepsirhine found in the rainforests of central Africa. In contrast to most primates, the potto shows slow-moving locomotion over the upper surface of branches, where it forages for exudates and crawling invertebrates with its head held very close to the substrate. Here, we asked whether the retina of the potto displays topographic specializations in neuronal density that correlate with its unusual lifestyle. Using stereology and retinal wholemounts, we measured the total number and topographic distribution of retinal ganglion cells (total and presumed parasol), as well as estimating the upper limits of the spatial resolution of the potto eye. We estimated ∼210,000 retinal ganglion cells, of which ∼7% (∼14,000) comprise presumed parasol ganglion cells. The topographic distribution of both total and parasol ganglion cells reveals a concentric centroperipheral organization with a nasoventral asymmetry. Combined with the upwardly shifted orbits of the potto, this nasoventral increase in parasol ganglion cell density enhances contrast sensitivity and motion detection skywards, which potentially assists with the detection of predators in the high canopy. The central area of the potto occurs ∼2.5 mm temporal to the optic disc and contains a maximum ganglion cell density of ∼4,300 cells/mm2. We found no anatomical evidence of a fovea within this region. Using maximum ganglion cell density and eye size (∼14 mm), we estimated upper limits of spatial resolving power between 4.1 and 4.4 cycles/degree. Despite their reported reliance on olfaction to detect exudates, this level of spatial resolution potentially assists pottos with foraging for small invertebrates and in the detection of predators.

scholarly journals Survival of retinal ganglion cells after damage to the occipital lobe in humans is activity dependent

2019 ◽  
Vol 286 (1897) ◽  
pp. 20182733 ◽  
Author(s):  
Colleen L. Schneider ◽  
Emily K. Prentiss ◽  
Ania Busza ◽  
Kelly Matmati ◽  
Nabil Matmati ◽  
...  
Keyword(s):  
Visual Cortex ◽  
Visual Field ◽  
Ganglion Cell ◽  
Retinal Ganglion Cells ◽  
Retinal Ganglion Cell ◽  
Ganglion Cells ◽  
Retinal Ganglion ◽  
Cell Degeneration ◽  
Visual Ability ◽  
Activity Dependent

Damage to the optic radiations or primary visual cortex leads to blindness in all or part of the contralesional visual field. Such damage disconnects the retina from its downstream targets and, over time, leads to trans-synaptic retrograde degeneration of retinal ganglion cells. To date, visual ability is the only predictor of retinal ganglion cell degeneration that has been investigated after geniculostriate damage. Given prior findings that some patients have preserved visual cortex activity for stimuli presented in their blind field, we tested whether that activity explains variability in retinal ganglion cell degeneration over and above visual ability. We prospectively studied 15 patients (four females, mean age = 63.7 years) with homonymous visual field defects secondary to stroke, 10 of whom were tested within the first two months after stroke. Each patient completed automated Humphrey visual field testing, retinotopic mapping with functional magnetic resonance imaging, and spectral-domain optical coherence tomography of the macula. There was a positive relation between ganglion cell complex (GCC) thickness in the blind field and early visual cortex activity for stimuli presented in the blind field. Furthermore, residual visual cortex activity for stimuli presented in the blind field soon after the stroke predicted the degree of retinal GCC thinning six months later. These findings indicate that retinal ganglion cell survival after ischaemic damage to the geniculostriate pathway is activity dependent.

Retinal ganglion cell density of the black rhinoceros (Diceros bicornis): Calculating visual resolution

2008 ◽  
Vol 25 (2) ◽  
pp. 215-220 ◽  
Author(s):  
JOHN D. PETTIGREW ◽  
PAUL R. MANGER
Keyword(s):  
Visual Field ◽  
Ganglion Cell ◽  
Cell Density ◽  
Visual Information ◽  
Ganglion Cells ◽  
Cell Types ◽  
Domestic Cat ◽  
Retinal Ganglion ◽  
Black Rhinoceros ◽  
Visual Resolution

AbstractA single right retina from a black rhinoceros was whole mounted, stained and analyzed to determine the visual resolution of the rhinoceros, an animal with reputedly poor eyesight. A range of small (15-μm diameter) to large (100-μm diameter) ganglion cell types was seen across the retina. We observed two regions of high density of retinal ganglion cells at either end of a long, but thin, horizontal streak. The temporal specialization, which receives light from the anterior visual field, exhibited a ganglion cell density of approximately 2000/mm2, while the nasal specialization exhibited a density of approximately 1500/mm2. The retina exhibited a ganglion cell density bias toward the upper half, especially so, the upper temporal quadrant, indicating that the rhinoceros would be processing visual information from the visual field below the anterior horizon for the most part. Our calculations indicate that the rhinoceros has a visual resolution of 6 cycles/degree. While this resolution is one-tenth that of humans (60 cycles/deg) and less than that of the domestic cat (9 cycles/deg), it is comparable to that of the rabbit (6 cycles/deg), and exceeds that seen in a variety of other mammals including seals, dolphins, microbats, and rats. Thus, the reputation of the rhinoceros as a myopic, weakly visual animal is not supported by our observations of the retina. We calculate that the black rhinoceros could readily distinguish a 30 cm wide human at a distance of around 200 m given the appropriate visual background.

scholarly journals Improvement in Inner Retinal Function in Glaucoma in Response to Nicotinamide (Vitamin B3) Supplementation: A Crossover Randomized Clinical Trial

2020 ◽  
Author(s):  
Flora Hui ◽  
Jessica Tang ◽  
Pete A Williams ◽  
Myra B McGuinness ◽  
Xavier Hadoux ◽  
...  
Keyword(s):  
Clinical Trial ◽  
Visual Field ◽  
Ganglion Cell ◽  
Retinal Ganglion Cells ◽  
Cell Function ◽  
Ganglion Cells ◽  
Retinal Function ◽  
Trial Registration ◽  
Retinal Ganglion ◽  
Retinal Ganglion Cell Function

AbstractImportanceRetinal ganglion cells endure significant metabolic stress with ageing and glaucoma-related stressors. Injured cells require increased energy for repair but maintain capacity to recover function despite periods of functional loss. Nicotinamide, a precursor of redox co-factor and metabolite, NAD+, is low in serum of patients with primary open-angle glaucoma and its supplementation provides robust protection of retinal ganglion cells by targeting mitochondrial health in glaucoma models. However, the potential of nicotinamide to improve retinal ganglion cell function in humans with glaucoma is yet unknown.ObjectiveTo determine whether nicotinamide supplementation taken in conjunction with conventional IOP-lowering therapy leads to early improvement in retinal ganglion cell function in people with glaucoma.DesignCrossover, double-masked, randomized clinical trial conducted between October 2017 to January 2019.SettingStudy participants recruited from two tertiary care centers in Melbourne, Australia.ParticipantsAdults diagnosed and treated for primary glaucoma. Ninety-four participants assessed for study eligibility.InterventionParticipants randomized to first receive oral placebo or nicotinamide and reviewed six-weekly. Accelerated dosing method utilized; participants commenced 6-week course of 1.5 grams/day followed by 6 weeks of 3.0 grams/day. After 12 weeks, participants crossed over to other intervention for 12 weeks without washout. At each visit, visual function measured using full-field flash electroretinography and white-on-white perimetry.Main outcome measuresPrimary endpoint was change in inner retinal function determined a-priori as change in photopic negative response (PhNR) parameters: saturated PhNR amplitude (Vmax), ratio of PhNR/b-wave amplitude (Vmax ratio).ResultsFifty-seven participants (65.5±10.0 years, 39% female) enrolled. PhNR Vmax improved beyond 95% coefficient of repeatability (COR) in 23% of participants following 12 weeks of nicotinamide versus 9% on placebo. Conversely, PhNR Vmax deteriorated in 9% on placebo and 7% on nicotinamide. Overall, Vmax improved by 14.8% [95% CI: 2.8%, 26.9%], (p=0.02) on nicotinamide and 5.2% [-4.2%, 14.6%], (p=0.27) on placebo. Vmax ratio improved on average by 12.6% [5.0%, 20.2%], (p=0.002) following nicotinamide and 3.6% [-3.4%, 10.5%], (p=0.30) on placebo. A concomitant trend for improved visual field mean deviation was observed with 27% improving ≥1dB on nicotinamide and fewer deteriorating ≥1dB (4%) compared to placebo (p=0.02). Moderate correlation was observed between PhNR and visual field change with treatment. Participants demonstrated excellent treatment adherence rates (>94%) and nicotinamide was well tolerated with minimal side effects.Conclusions and RelevanceNicotinamide supplementation can improve inner retinal function in patients receiving concurrent IOP-lowering glaucoma therapy. Further studies are underway to elucidate the effects of long-term nicotinamide supplementation on glaucoma progression.Trial RegistrationANZCTR trial ID: ACTRN12617000809336 https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=373001

scholarly journals Hop flower extracts mitigate retinal ganglion cell degeneration in a glaucoma mouse model

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Tomoko Hasegawa ◽  
Hanako O. Ikeda ◽  
Sachiko Iwai ◽  
Norio Sasaoka ◽  
Akira Kakizuka ◽  
...  
Keyword(s):  
Intraocular Pressure ◽  
Visual Field ◽  
Ganglion Cell ◽  
Retinal Ganglion Cells ◽  
Ganglion Cells ◽  
Amyloid Β ◽  
Visual Field Loss ◽  
Retinal Ganglion ◽  
Cell Degeneration ◽  
Novel Therapeutic

AbstractIn glaucoma, retinal ganglion cells degenerate progressively, leading to visual field loss and blindness. Presently, the only treatment strategy for glaucoma is lowering the intraocular pressure. However, there are cases in which patients develop progressive visual field loss even though their intraocular pressures are within normal ranges. Therefore, the development of novel therapeutic strategies is an urgent endeavor. Besides high intraocular pressure, several other factors have been proposed to be associated with glaucoma progression, e.g., myopia, blood flow impairment, and amyloid β accumulation. We have previously reported that hop flower extracts possess γ-secretase inhibitory activities and reduce amyloid β deposition in the brains of Alzheimer’s disease model mice. In the current study, we showed that administration of hop flower extracts to glutamate-aspartate transporter (GLAST) knockout mice, the glaucoma model mice, attenuated glaucomatous retinal ganglion cell degeneration. Preservation of retinal ganglion cells in hop flower extract-administered mice was confirmed using optical coherence tomography, confocal scanning laser ophthalmoscopy, and retinal flatmount and histological evaluations. Hop flower extracts are, therefore, deemed a possible candidate as a novel therapeutic agent to treat glaucoma.

scholarly journals Dynamic Expression of HDAC3 in db/db Mouse RGCs and Its Relationship with Apoptosis and Autophagy

2020 ◽  
Vol 2020 ◽  
pp. 1-8
Author(s):  
Yuhong Fu ◽  
Ying Wang ◽  
Xinyuan Gao ◽  
Huiyao Li ◽  
Yue Yuan
Keyword(s):  
Diabetic Retinopathy ◽  
Ganglion Cell ◽  
Retinal Ganglion Cells ◽  
Retinal Ganglion Cell ◽  
Ganglion Cells ◽  
Control Group ◽  
Diabetic Patients ◽  
Retinal Ganglion ◽  
Glucose Levels ◽  
Dynamic Expression

Background. Diabetic retinopathy (DR) is a severe complication of diabetes mellitus. DR is considered as a neurovascular disease. Retinal ganglion cell (RGC) loss plays an important role in the vision function disorder of diabetic patients. Histone deacetylase3 (HDAC3) is closely related to injury repair and nerve regeneration. The correlation between HDAC3 and retinal ganglion cells in diabetic retinopathy is still unclear yet. Methods. To investigate the chronological sequence of the abnormalities of retinal ganglion cells in diabetic retinopathy, we choose 15 male db/db mice (aged 8 weeks, 12 weeks, 16 weeks, 18 weeks, and 25 weeks; each group had 3 mice) as diabetic groups and 3 male db/m mice (aged 8 weeks) as the control group. In this study, we examined the morphological and immunohistochemical changes of HDAC3, Caspase3, and LC3B in a sequential manner by characterizing the process of retinal ganglion cell variation. Results. Blood glucose levels and body weights of db/db mice were significantly higher than that of the control group, P<0.01. Compared with the control group, the number of retinal ganglion cells decreased with the duration of disease increasing. HDAC3 expression gradually increased in RGCs of db/db mice. Caspase3 expression gradually accelerated in RGCs of db/db mice. LC3B expression dynamically changed in RGCs of db/db mice. HDAC3 was positively correlated with Caspase3 expression (r=0.7424), P<0.01. HDAC3 was positively correlated with LC3B expression (r=0.7336), P<0.01. Discussion. We clarified the dynamic expression changes of HDAC3, Caspase3, and LC3B in retinal ganglion cells of db/db mice. Our results suggest the HDAC3 expression has a positive correlation with apoptosis and autophagy.

scholarly journals Spatial receptive field properties of rat retinal ganglion cells

2011 ◽  
Vol 28 (5) ◽  
pp. 403-417 ◽  
Author(s):  
WALTER F. HEINE ◽  
CHRISTOPHER L. PASSAGLIA
Keyword(s):  
Receptive Field ◽  
Ganglion Cell ◽  
Retinal Ganglion Cells ◽  
Ganglion Cells ◽  
Cell Types ◽  
Quantitative Information ◽  
Retinal Ganglion ◽  
X And Y Cells ◽  
Y Cells

AbstractThe rat is a popular animal model for vision research, yet there is little quantitative information about the physiological properties of the cells that provide its brain with visual input, the retinal ganglion cells. It is not clear whether rats even possess the full complement of ganglion cell types found in other mammals. Since such information is important for evaluating rodent models of visual disease and elucidating the function of homologous and heterologous cells in different animals, we recorded from rat ganglion cells in vivo and systematically measured their spatial receptive field (RF) properties using spot, annulus, and grating patterns. Most of the recorded cells bore likeness to cat X and Y cells, exhibiting brisk responses, center-surround RFs, and linear or nonlinear spatial summation. The others resembled various types of mammalian W cell, including local-edge-detector cells, suppressed-by-contrast cells, and an unusual type with an ON–OFF surround. They generally exhibited sluggish responses, larger RFs, and lower responsiveness. The peak responsivity of brisk-nonlinear (Y-type) cells was around twice that of brisk-linear (X-type) cells and several fold that of sluggish cells. The RF size of brisk-linear and brisk-nonlinear cells was indistinguishable, with average center and surround diameters of 5.6 ± 1.3 and 26.4 ± 11.3 deg, respectively. In contrast, the center diameter of recorded sluggish cells averaged 12.8 ± 7.9 deg. The homogeneous RF size of rat brisk cells is unlike that of cat X and Y cells, and its implication regarding the putative roles of these two ganglion cell types in visual signaling is discussed.

Specification of retinotectal connexions during development of the toad Xenopus laevis

Development ◽  
1980 ◽  
Vol 55 (1) ◽  
pp. 77-92
Author(s):  
S. C. Sharma ◽  
J. G. Hollyfield
Keyword(s):  
Xenopus Laevis ◽  
Ganglion Cell ◽  
Retinal Ganglion Cells ◽  
Optic Tectum ◽  
Ganglion Cells ◽  
The Other ◽  
Retinal Ganglion ◽  
Visual Projection ◽  
Series Of Experiments ◽  
The Right

The specification of central connexions of retinal ganglion cells was studied in Xenopus laevis. In one series of experiments, the right eye primordium was rotated 180° at embryonic stages 24–32. In the other series, the left eye was transplanted into the right orbit, and vice versa, with either 0° or 180° rotation. After metamorphosis the visual projections from the operated eye to the contralateral optic tectum were mapped electrophysiologically and compared with the normal retinotectal map. In all cases the visual projection map was rotated through the same angle as was indicated by the position of the choroidal fissure. The left eye exchanged into the right orbit retained its original axes and projected to the contralateral tectum. These results suggest that retinal ganglion cell connexions are specified before stage 24.

The retinal ganglion cell distribution and the representation of the visual field in area 17 of the owl monkey, Aotus trivirgatus

1993 ◽  
Vol 10 (5) ◽  
pp. 887-897 ◽  
Author(s):  
L. C. L. Silveira ◽  
V. H. Perry ◽  
E. S. Yamada
Keyword(s):  
Visual Cortex ◽  
Visual Field ◽  
Ganglion Cell ◽  
Cell Density ◽  
Ganglion Cells ◽  
Amacrine Cells ◽  
Temporal Region ◽  
Cell Distribution ◽  
Area 17 ◽  
Displaced Amacrine Cells

AbstractThe distribution of ganglion cells and displaced amacrine cells was determined in whole-mounted Aotus retinae. In contrast to diurnal simians, Aotus has only a rudimentary fovea. Ganglion cell density decreases towards the periphery at approximately the same rate along all meridians, but is 1.2–1.8 times higher in the nasal periphery when compared to temporal region at the same eccentricities. The total number of ganglion cells varied from 421,500 to 508,700. Ganglion cell density peaked at 15,000/mm2 at 0.25 mm dorsal to the fovea. The displaced amacrine cells have a shallow density gradient, their peak density in the central region is about 1500–2000/mm2 and their total number varied from 315,900 to 482,800. Comparison between ganglion cell density and areal cortical magnification factor for the primary visual cortex, area 17, shows that there is not a simple proportional representation of the ganglion cell distribution. There is an overrepresentation of the central 10 deg of the visual field in the visual cortex. The present results for Aotus and the results of a similar analysis of data from other primates indicate that the overrepresentation of the central visual field is a general feature of the visual system of primates.

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