scholarly journals Light responses and light adaptation in rat retinal rods at different temperatures

2005 ◽  
Vol 567 (3) ◽  
pp. 923-938 ◽  
Author(s):  
S. Nymark ◽  
H. Heikkinen ◽  
C. Haldin ◽  
K. Donner ◽  
A. Koskelainen
Keyword(s):  
Light Adaptation ◽  
Light Responses ◽  
Retinal Rods ◽  
Different Temperatures

scholarly journals Dopamine D1 receptor activation contributes to light-adapted changes in retinal inhibition to rod bipolar cells

2018 ◽  
Vol 120 (2) ◽  
pp. 867-879 ◽  
Author(s):  
Michael D. Flood ◽  
Johnnie M. Moore-Dotson ◽  
Erika D. Eggers
Keyword(s):  
Light Adaptation ◽  
Amacrine Cell ◽  
Amacrine Cells ◽  
Receptor Activation ◽  
Bipolar Cells ◽  
D1 Receptor ◽  
D1 Receptors ◽  
Light Responses ◽  
Dopamine Modulation ◽  
Rod Bipolar Cells

Dopamine modulation of retinal signaling has been shown to be an important part of retinal adaptation to increased background light levels, but the role of dopamine modulation of retinal inhibition is not clear. We previously showed that light adaptation causes a large reduction in inhibition to rod bipolar cells, potentially to match the decrease in excitation after rod saturation. In this study, we determined how dopamine D1 receptors in the inner retina contribute to this modulation. We found that D1 receptor activation significantly decreased the magnitude of inhibitory light responses from rod bipolar cells, whereas D1 receptor blockade during light adaptation partially prevented this decline. To determine what mechanisms were involved in the modulation of inhibitory light responses, we measured the effect of D1 receptor activation on spontaneous currents and currents evoked from electrically stimulating amacrine cell inputs to rod bipolar cells. D1 receptor activation decreased the frequency of spontaneous inhibition with no change in event amplitudes, suggesting a presynaptic change in amacrine cell activity in agreement with previous reports that rod bipolar cells lack D1 receptors. Additionally, we found that D1 receptor activation reduced the amplitude of electrically evoked responses, showing that D1 receptors can modulate amacrine cells directly. Our results suggest that D1 receptor activation can replicate a large portion but not all of the effects of light adaptation, likely by modulating release from amacrine cells onto rod bipolar cells. NEW & NOTEWORTHY We demonstrated a new aspect of dopaminergic signaling that is involved in mediating light adaptation of retinal inhibition. This D1 receptor-dependent mechanism likely acts through receptors located directly on amacrine cells, in addition to its potential role in modulating the strength of serial inhibition between amacrine cells. Our results also suggest that another D2/D4 receptor-dependent or dopamine-independent mechanism must also be involved in light adaptation of inhibition to rod bipolar cells.

scholarly journals Light adaptation in retinal rods of the rabbit and two other nonprimate mammals.

1991 ◽  
Vol 97 (3) ◽  
pp. 413-435 ◽  
Author(s):  
K Nakatani ◽  
T Tamura ◽  
K W Yau
Keyword(s):  
Light Adaptation ◽  
Evoked Responses ◽  
Flash Intensity ◽  
Exponential Form ◽  
Time To Peak ◽  
Outward Currents ◽  
Retinal Rods ◽  
Response Peak ◽  
Flash Response ◽  
Plateau Level

The responses of rabbit rods to light were studied by drawing a single rod outer segment projecting from a small piece of retina into a glass pipette to record membrane current. The bath solution around the cells was maintained at near 40 degrees C. Light flashes evoked transient outward currents that saturated at up to approximately 20 pA. One absorbed photon produced a response of approximately 0.8 pA at peak. At the rising phase of the flash response, the relation between response amplitude and flash intensity (IF) had the exponential form 1-e-kappa FIF (where kappa F is a constant denoting sensitivity) expected from the absence of light adaptation. At the response peak, however, the amplitude-intensity relation fell slightly below the exponential form. At times after the response peak, the deviation was progressively more substantial. Light steps evoked responses that rose to a transient peak and rapidly relaxed to a lower plateau level. The response-intensity relation again indicated that light adaptation was insignificant at the early rising phase of the response, but became progressively more prominent at the transient peak and the steady plateau of the response. Incremental flashes superposed on a steady light of increasing intensity evoked responses that had a progressively shorter time-to-peak and faster relaxation, another sign of light adaptation. The flash sensitivity changed according to the Weber-Fechner relation (i.e., inversely) with background light intensity. We conclude that rabbit rods adapt to light in a manner similar to rods in cold-blooded vertebrates. Similar observations were made on cattle and rat rods.

Properties of light adaptation in retinal rods

1992 ◽  
Vol 55 ◽  
pp. 71
Author(s):  
L. Cervetto ◽  
S. Bisti ◽  
A. Campagni ◽  
S. Del Bianco ◽  
G.C. Demontis ◽  
...  
Keyword(s):  
Light Adaptation ◽  
Retinal Rods

Sodium nitroprusside alters dark voltage and light responses in isolated retinal rods during whole-cell recording

1992 ◽  
Vol 9 (2) ◽  
pp. 205-209 ◽  
Author(s):  
Karl-Friedrich Schmidt ◽  
Gottfried N. Nöll ◽  
Yoshihiko Yamamoto
Keyword(s):  
Sodium Nitroprusside ◽  
Rana Esculenta ◽  
Recovery Phase ◽  
Patch Clamp Technique ◽  
Light Responses ◽  
Whole Cell ◽  
Whole Cell Recording ◽  
Retinal Rods ◽  
Cell Recording ◽  
Nitric Oxide Releasing

AbstractDark voltage and light responses of isolated retinal rods of Rana esculenta were investigated by employing the whole-cell patch-clamp technique. When the recording pipette was filled with a medium devoid of nucleotides, a spontaneous hyperpolarization of the dark voltage partly due to a diffusional loss of cGMP and its precursor GTP and a retardation in the recovery of the light responses was observed. The larger part of the retardation of the light responses was prevented by 1 mM ATP. Addition of GTP attenuated the hyperpolarization, but did not abolish it completely. When the nitric-oxide-releasing substance sodium nitroprusside plus GTP was applied, the tendency of hyperpolarization disappeared and a stable dark voltage or even a slight depolarization was measured during the whole-cell recording period. Similar results were also obtained when GTP was given in combination with either EGTA or IBMX which are both known to interfere with the cGMP regulating enzymes in retinal rods. In addition to its effects on the dark voltage, an acceleration of the recovery phase of the light responses by sodium nitroprusside was also observed. Our observations strongly suggest that sodium nitroprusside activates guanylate cyclase in photoreceptors, as it does in other tissues, but we cannot exclude with certainty an effect on the phosphodiesterase.

Calcium and light adaptation in retinal rods and cones

Nature ◽  
1988 ◽  
Vol 334 (6177) ◽  
pp. 69-71 ◽  
Author(s):  
K. Nakatani ◽  
K.-W. Yau
Keyword(s):  
Light Adaptation ◽  
Rods And Cones ◽  
Retinal Rods

Light Adaptation in Retinal Rods of the Newt

1990 ◽  
pp. 205-226
Author(s):  
S. Forti ◽  
A. Menini ◽  
G. Rispoli ◽  
L. Spadavecchia ◽  
V. Torre
Keyword(s):  
Light Adaptation ◽  
Retinal Rods

scholarly journals Effect of blocking the Na+/K+ ATPase on Ca2+ extrusion and light adaptation in mammalian retinal rods

1995 ◽  
Vol 69 (2) ◽  
pp. 439-450 ◽  
Author(s):  
G.C. Demontis ◽  
G.M. Ratto ◽  
S. Bisti ◽  
L. Cervetto
Keyword(s):  
Light Adaptation ◽  
Retinal Rods

Light responses from one type of ON-OFF amacrine cells in the rabbit retina

1995 ◽  
Vol 74 (6) ◽  
pp. 2460-2468 ◽  
Author(s):  
R. F. Dacheux ◽  
E. Raviola
Keyword(s):  
Light Adaptation ◽  
Receptive Fields ◽  
Central Area ◽  
Plexiform Layer ◽  
Light Response ◽  
Amacrine Cells ◽  
Wide Field ◽  
Inner Plexiform Layer ◽  
Rabbit Retina ◽  
Light Responses

1. The light responses from one type of ON-OFF amacrine cell were recorded intracellularly in the superfused rabbit retina under various conditions of light adaptation. These recordings were obtained from cells located in a central area. 5-7 mm inferior and directly below the optic nerve head. 2. ON-OFF amacrine cells responded to the initiation and termination of light stimuli with transient depolarizations. Their receptive fields were approximately 0.8-1 mm diam and did not exhibit antagonistic center-and-surround organization. 3. The cells received rod input because they responded to very dim scotopic stimuli. With prolonged dark adaptation, the cells became more sensitive to the initiation than termination of the stimulus, because the ON component of the light response had a lower threshold than the OFF component. 4. The cells continued to respond to test flashes when the retina was adapted to a background illumination of rod-saturating intensity. Thus ON-OFF amacrine cells also receive cone input. Under these photopic conditions, a secondary afterpotential was observed following the OFF component. Its characteristics were different from those of the rod aftereffect reported in other retinal cells of the rabbit because its latency and amplitude changed with increasing stimulus intensity. 5. Intracellular injections of horseradish peroxidase showed that the recordings were obtained from a class of ON-OFF amacrine cells whose wide-field, unistratified dendrites were rigorously confined to the middle of the inner plexiform layer or stratum 3. 6. The conspicuous rod and cone inputs into a class of amacrine cells that are connected neither to rod bipolars nor to All amacrine cells strongly support the idea that in the rabbit the rod pathway uses cone bipolars as interneurons to distribute scotopic signals to ganglion and cone-driven amacrine cells.

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