Relation of Brightness to Threshold for Light-Adapted and Dark-Adapted Rods and Cones: Effects of Retinal Eccentricity and Target Size

Perception ◽  
1980 ◽  
Vol 9 (6) ◽  
pp. 633-650 ◽  
Author(s):  
Bruce Drum
Keyword(s):  
Retinal Ganglion Cells ◽  
Channel Model ◽  
Ganglion Cells ◽  
The Other ◽  
Target Size ◽  
Retinal Eccentricity ◽  
Retinal Ganglion ◽  
Threshold Functions ◽  
Rods And Cones ◽  
Matching Procedure

‘Equal-brightness' functions of retinal eccentricity and target diameter were measured by a matching procedure, and compared with the corresponding threshold functions for four different adaptation conditions: light-adapted cones (LAC), dark-adapted cones (DAC), light-adapted rods (LAR) and dark-adapted rods (DAR). The separation between log brightness matches and log thresholds decreased with eccentricity and increased with target size for all adaptation conditions, but overall separation was substantially greater for the DAR condition than for the other three. A two-channel model of achromatic brightness is proposed to explain the results. The model assumes ‘strong’ and ‘weak’ channels, which contribute unequally to brightness. These channels are tentatively identified with tonic and phasic classes of retinal ganglion cells.

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.

scholarly journals Contribution of human melanopsin retinal ganglion cells to steady-state pupil responses

2010 ◽  
Vol 277 (1693) ◽  
pp. 2485-2492 ◽  
Author(s):  
Sei-ichi Tsujimura ◽  
Kazuhiko Ukai ◽  
Daisuke Ohama ◽  
Atsuo Nuruki ◽  
Kazutomo Yunokuchi
Keyword(s):  
Steady State ◽  
Retinal Ganglion Cells ◽  
Ganglion Cells ◽  
Pupil Diameter ◽  
Retinal Ganglion ◽  
Silent Substitution ◽  
Conventional View ◽  
Rods And Cones ◽  
Direct Measurements ◽  
Stimulation System

The recent discovery of melanopsin-containing retinal ganglion cells (mRGCs) has led to a fundamental reassessment of non-image forming processing, such as circadian photoentrainment and the pupillary light reflex. In the conventional view of retinal physiology, rods and cones were assumed to be the only photoreceptors in the eye and were, therefore, considered responsible for non-image processing. However, signals from mRGCs contribute to this non-image forming processing along with cone-mediated luminance signals; although both signals contribute, it is unclear how these signals are summed. We designed and built a novel multi-primary stimulation system to stimulate mRGCs independently of other photoreceptors using a silent-substitution technique within a bright steady background. The system allows direct measurements of pupillary functions for mRGCs and cones. We observed a significant change in steady-state pupil diameter when we varied the excitation of mRGC alone, with no change in luminance and colour. Furthermore, the change in pupil diameter induced by mRGCs was larger than that induced by a variation in luminance alone: that is, for a bright steady background, the mRGC signals contribute to the pupillary pathway by a factor of three times more than the L- and M-cone signals.

scholarly journals Functional diversity of human intrinsically photosensitive retinal ganglion cells

Science ◽  
2019 ◽  
Vol 366 (6470) ◽  
pp. 1251-1255 ◽  
Author(s):  
Ludovic S. Mure ◽  
Frans Vinberg ◽  
Anne Hanneken ◽  
Satchidananda Panda
Keyword(s):  
Retinal Ganglion Cells ◽  
Preparation Method ◽  
Ganglion Cells ◽  
Organ Donor ◽  
Retinal Ganglion ◽  
Visual Responses ◽  
Human Organ ◽  
Rods And Cones ◽  
Light Signals ◽  
Human And Mouse

Intrinsically photosensitive retinal ganglion cells (ipRGCs) are a subset of cells that participate in image-forming and non–image-forming visual responses. Although both functional and morphological subtypes of ipRGCs have been described in rodents, parallel functional subtypes have not been identified in primate or human retinas. In this study, we used a human organ donor preparation method to measure human ipRGCs’ photoresponses. We discovered three functional ipRGC subtypes with distinct sensitivities and responses to light. The response of one ipRGC subtype appeared to depend on exogenous chromophore supply, and this response is conserved in both human and mouse retinas. Rods and cones also provided input to ipRGCs; however, each subtype integrated outer retina light signals in a distinct fashion.

Susceptibility of retinal ganglion cells to excitotoxicity depends on soma size and retinal eccentricity

1999 ◽  
Vol 19 (1) ◽  
pp. 59-65 ◽  
Author(s):  
C.K. Vorwerk ◽  
M.R. Kreutz ◽  
T.M. Böckers ◽  
M. Brosz ◽  
E.B. Dreyer ◽  
...  
Keyword(s):  
Retinal Ganglion Cells ◽  
Ganglion Cells ◽  
Retinal Eccentricity ◽  
Retinal Ganglion ◽  
Soma Size

scholarly journals Intrinsically Photosensitive Retinal Ganglion Cells of the Human Retina

2021 ◽  
Vol 12 ◽  
Author(s):  
Ludovic S. Mure
Keyword(s):  
Retinal Ganglion Cells ◽  
Ganglion Cells ◽  
Life Quality ◽  
Well Being ◽  
Therapeutic Interventions ◽  
Diagnostic Tools ◽  
Human Retina ◽  
Retinal Ganglion ◽  
Rods And Cones ◽  
Light And Gene Expression

Light profoundly affects our mental and physical health. In particular, light, when not delivered at the appropriate time, may have detrimental effects. In mammals, light is perceived not only by rods and cones but also by a subset of retinal ganglion cells that express the photopigment melanopsin that renders them intrinsically photosensitive (ipRGCs). ipRGCs participate in contrast detection and play critical roles in non-image-forming vision, a set of light responses that include circadian entrainment, pupillary light reflex (PLR), and the modulation of sleep/alertness, and mood. ipRGCs are also found in the human retina, and their response to light has been characterized indirectly through the suppression of nocturnal melatonin and PLR. However, until recently, human ipRGCs had rarely been investigated directly. This gap is progressively being filled as, over the last years, an increasing number of studies provided descriptions of their morphology, responses to light, and gene expression. Here, I review the progress in our knowledge of human ipRGCs, in particular, the different morphological and functional subtypes described so far and how they match the murine subtypes. I also highlight questions that remain to be addressed. Investigating ipRGCs is critical as these few cells play a major role in our well-being. Additionally, as ipRGCs display increased vulnerability or resilience to certain disorders compared to conventional RGCs, a deeper knowledge of their function could help identify therapeutic approaches or develop diagnostic tools. Overall, a better understanding of how light is perceived by the human eye will help deliver precise light usage recommendations and implement light-based therapeutic interventions to improve cognitive performance, mood, and life quality.

scholarly journals Mechanisms and Distribution of Ion Channels in Retinal Ganglion Cells: Using Temperature as an Independent Variable

2010 ◽  
Vol 103 (3) ◽  
pp. 1357-1374 ◽  
Author(s):  
Jürgen F. Fohlmeister ◽  
Ethan D. Cohen ◽  
Eric A. Newman
Keyword(s):  
Retinal Ganglion Cells ◽  
Action Potentials ◽  
Channel Model ◽  
Ganglion Cells ◽  
Safety Margin ◽  
Delayed Rectifier ◽  
Na Channel ◽  
Retinal Ganglion ◽  
Temperature Dependent ◽  
Cell Recording

Trains of action potentials of rat and cat retinal ganglion cells (RGCs) were recorded intracellularly across a temperature range of 7–37°C. Phase plots of the experimental impulse trains were precision fit using multicompartment simulations of anatomically reconstructed rat and cat RGCs. Action potential excitation was simulated with a “Five-channel model” [Na, K(delayed rectifier), Ca, K(A), and K(Ca-activated) channels] and the nonspace-clamped condition of the whole cell recording was exploited to determine the channels' distribution on the dendrites, soma, and proximal axon. At each temperature, optimal phase-plot fits for RGCs occurred with the same unique channel distribution. The “waveform” of the electrotonic current was found to be temperature dependent, which reflected the shape changes in the experimental action potentials and confirmed the channel distributions. The distributions are cell-type specific and adequate for soma and dendritic excitation with a safety margin. The highest Na-channel density was found on an axonal segment some 50–130 μm distal to the soma, as determined from the temperature-dependent “initial segment–somadendritic (IS-SD) break.” The voltage dependence of the gating rate constants remains invariant between 7 and 23°C and between 30 and 37°C, but undergoes a transition between 23 and 30°C. Both gating-kinetic and ion-permeability Q10s remain virtually constant between 23 and 37°C (kinetic Q10s = 1.9–1.95; permeability Q10s = 1.49–1.64). The Q10s systematically increase for T <23°C (kinetic Q10 = 8 at T = 8°C). The Na channels were consistently “sleepy” (non-Arrhenius) for T <8°C, with a loss of spiking for T <7°C.

Morphology, dendritic field size, somal size, density, and coverage of M and P retinal ganglion cells of dichromatic Cebus monkeys

1996 ◽  
Vol 13 (6) ◽  
pp. 1011-1029 ◽  
Author(s):  
Elizabeth S. Yamada ◽  
Luiz Carlos L. Silveira ◽  
V. Hugh Perry
Keyword(s):  
Retinal Ganglion Cells ◽  
Ganglion Cells ◽  
Dendritic Tree ◽  
Field Size ◽  
Retinal Eccentricity ◽  
Temporal Region ◽  
Retinal Ganglion ◽  
Dendritic Field ◽  
Retrograde Filling

AbstractMale Cebus monkeys are all dichromats, but about two thirds of the females are trichromats. M and P retinal ganglion cells were studied in the male Cebus monkey to investigate the relationship of their morphology to retinal eccentricity. Retinal ganglion cells were retrogradely labeled after optic nerve deposits of biocytin to reveal their entire dendritic tree. Cebus M and P ganglion cell morphology revealed by biocytin retrograde filling is similar to that described for macaque and human M and P ganglion cells obtained by in vitro intracellular injection of HRP and neurobiotin. We measured 264 and 441 M and P ganglion cells, respectively. M ganglion cells have larger dendritic field and cell body size than P ganglion cells at any comparable temporal or nasal eccentricity. Dendritic trees of both M and P ganglion cells are smaller in the nasal than in the temporal region at eccentricities greater than 5 mm and 2 mm for M and P ganglion cells, respectively. The depth of terminal dendrites allows identification of both inner and outer subclasses of M and P ganglion cells. The difference in dendritic tree size between inner and outer cells is small or absent. Comparison between Cebus and Macaca shows that M and P ganglion cells have similar sizes in the central retinal region. The results support the view that M and P pathways are similarly organized in diurnal dichromat and trichromat primates.

scholarly journals Intrinsically Photosensitive Retinal Ganglion Cells

2010 ◽  
Vol 90 (4) ◽  
pp. 1547-1581 ◽  
Author(s):  
Michael Tri Hoang Do ◽  
King-Wai Yau
Keyword(s):  
Retinal Ganglion Cells ◽  
Ganglion Cells ◽  
Small Population ◽  
Retinal Ganglion ◽  
Visual Functions ◽  
Rods And Cones ◽  
Living Things ◽  
Rotation Of The Earth ◽  
Life On Earth ◽  
And Behavior

Life on earth is subject to alternating cycles of day and night imposed by the rotation of the earth. Consequently, living things have evolved photodetective systems to synchronize their physiology and behavior with the external light-dark cycle. This form of photodetection is unlike the familiar “image vision,” in that the basic information is light or darkness over time, independent of spatial patterns. “Nonimage” vision is probably far more ancient than image vision and is widespread in living species. For mammals, it has long been assumed that the photoreceptors for nonimage vision are also the textbook rods and cones. However, recent years have witnessed the discovery of a small population of retinal ganglion cells in the mammalian eye that express a unique visual pigment called melanopsin. These ganglion cells are intrinsically photosensitive and drive a variety of nonimage visual functions. In addition to being photoreceptors themselves, they also constitute the major conduit for rod and cone signals to the brain for nonimage visual functions such as circadian photoentrainment and the pupillary light reflex. Here we review what is known about these novel mammalian photoreceptors.

Properties and tectal projections of monkey retinal ganglion cells

1977 ◽  
Vol 40 (2) ◽  
pp. 428-445 ◽  
Author(s):  
P. H. Schiller ◽  
J. G. Malpeli
Keyword(s):  
Superior Colliculus ◽  
Retinal Ganglion Cells ◽  
Ganglion Cells ◽  
Broad Band ◽  
Optic Chiasm ◽  
Retinal Eccentricity ◽  
Relative Distribution ◽  
Retinal Ganglion ◽  
Antidromic Activation ◽  
Group 5

1. Extracellular single-unit recordings were undertaken in the retina of the rhesus monkey in order to assess the receptive-field properties of those ganglion cells which project to the superior colliculus. Cells were tested for antidromic activation from the superior colliculus, lateral geniculate nucleus, and the optic chiasm. 2. The majority of retinal ganglion cells could be classified as color opponent or broad band. A small, heterogeneous group could not be so classified and were collectively referred to as "rarely encountered" cells. 3. Color-opponent cells responded in a sustained fashion and broad-band cells in a transient fashion to visual stimuli. Quantitative assessment of response transiency shows that this measure reliably differentiates these two classes. 4. To moving sinusoidal gratings broad-band cells responded more vigorously and with greater temporal modulation than did color-opponent cells. 5. The distributions of conduction velocities of different classes of neurons showed considerable overlap. On the average, axons of broadband neurons conducted most rapidly and rarely encountered types, most slowly. 6. The population of cells projecting to the superior colliculus does not contain color-opponent cells. The retinotectal cells respond predominantly in a transient fashion. Only 3.9% of broad-band cells (26 of 663) were antidromically driven from the superior colliculus, while 29% of the rarely encountered group (5 of 17) could be so activated. 7. The relative distribution of color-opponent and broad-band cells does not appear to change with retinal eccentricity within the central 20 degrees.

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