The response to electric stimulation of horizontal cells in the carp retina

Byzov, A. L.; Trifonov, Ju.A.

doi:10.1016/0042-6989(68)90132-6

Cited by 87 publications

(29 citation statements)

References 1 publication

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“…7, left column), the waveforms of the evoked potentials were biphasic in the cone as well as in the horizontal cell. The latency of the transient EPSP was very short (about 1 msec, KANEKO and SHIMAZAKI, 1976) ; the time to its peak was about 10 msec, and a marked transient hyperpolarization followed (BYZOV and TRIFONOV, 1968). In the cone, a negative phase reached its peak about 25 msec later than that of the EPSP of the horizontal cell, and a prominent positive phase followed.…”

Section: Neural Mechanism Producing Biphasic Waveform In Conesmentioning

confidence: 93%

“…The photoreceptors of the vertebrate retina are so regularly arranged that a transretinal current pulse, flowing from the receptor side to the vitreal side, effectively depolarizes the cone terminals, activates transmitter release, and thereby generates a transient depolarization (EPSP) in the horizontal cells (TRIFONOV, 1968;BYZOV and TRIFONOV, 1968;TRIFONOV et al, 1974;KANEKO and SHIMAZAKI, 1976;WATANABE et al, 1978). The transient EPSP's thus evoked in the horizontal cells are shown in Fig.…”

Section: Methodsmentioning

confidence: 99%

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GABA-mediated negative feedback from horizontal cells to cones in carp retina.

et al. 1982

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In the isolated, perfused retina of the carp, properties of the feedback pathway from horizontal cells to cones were investigated by means of electrophysiological and neuropharmacological methods. When horizontal cells were hyperpolarized by illumination with an annulus, a depolarizing synaptic potential was produced in cones at the center of the annulus, suggesting that horizontal cells receive inputs from cones and exert a negative feedback to cones. On the other hand, a hyperpolarizing response (IPSP) was detected in cones, when a transient depolarization (EPSP) was induced in horizontal cells by application of a transretinal current pulse, which activated the release of transmitter from the photoreceptor terminals. The IPSP was abolished when the retina was perfused with a GABA-containing Ringer solution, because of desensitization of the feedback synapse. GABA also hyperpolarized the cone membrane, indicating the presence of a GABA-sensitive site in the cone. These results suggest that the GABA-mediated negative feedback operates from horizontal cells to cones in the dark, and ceases its function in the light.

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Section: Neural Mechanism Producing Biphasic Waveform In Conesmentioning

confidence: 93%

Section: Methodsmentioning

confidence: 99%

GABA-mediated negative feedback from horizontal cells to cones in carp retina.

et al. 1982

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“…It is thought that photoreceptor terminals release more depolarizing transmitter in the dark than in the light (18)(19)(20)(21) (25). This elevation of cAMP may be indicative of phosphorylase activation, a process in which cAMP plays an important role (26).…”

Section: Resultsmentioning

confidence: 99%

Distribution of 3':5'-cyclic AMP and 3':5'-cyclic GMP in rabbit retina in vivo: selective effects of dark and light adaptation and ischemia.

Orr¹,

Lowry²,

Cohen³

et al. 1976

Proc. Natl. Acad. Sci. U.S.A.

110

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By use of highly sensitive radioimmunoassays, 3':5'-cyclic AMP (cAMP) and 3':5'-cyclic GMP (cGMP) were measured in individual layers of light-and dark-adapted rabbit retinas, and the effects of ischemia were determined. In lightadapted retinas, cGMP levels ranged 50-fold, with over 90% of the total concentrated in the photoreceptor cells. The layer of outer segments contained 95 gmol/kg of dry weight, or three times the concentration present in the remainder of the photoreceptor cell layers. By contrast, levels of cAMP varied only 4-fold; the lowest level (6 gmol/kg of dry weight) was found in the outer segment layer and the highest level (22 ;mol/kg of dry weight) in the inner segment layer of the photoreceptor cells. Dark adaptation elevated cGMP levels only in retinal layers containing photoreceptor cells, and the greatest proportional increase was observed in the synaptic layer of photoreceptor cells. Dark adaptation also caused increases of cAMP that were restricted to the outer plexiform and outer nuclear layers. Ischemia lowered cGMP levels, but only in retinal layers containing photoreceptor cells, and elevated cAMP levels, primarily in the inner layers of the retina. emia was studied. The findings demonstrate that the cyclic nucleotides are discretely localized in retinas and that both light exposure and ischemia produce regionally selective changes in their levels. MATERIALS AND METHODS Tissue Preparation. Randomly bred, 6-month-old pigmented rabbits were obtained locally. Light adaptation consisted of 1 hr of exposure to two 100-watt tungsten bulbs about 25 cm above the rabbits. After the photopic stimulation, the rabbits were killed by decapitation. The eyes were removed, and after various ischemic periods in room light, were quickly frozen in liquid N2 cooled to its freezing point by partial evaporation under reduced pressure. Consequently, the liquid N2 does not boil when the eyes are immersed, and freezing is quicker. Dark adaptation consisted of an overnight period in cages wrapped with black cloth and placed in a completely dark room. After decapitation in this room, the dark-adapted eyes were dissected free with the aid of an infrared light source and an infrared image converter, and after various periods, were frozen in the dark as above. Under the most ideal conditions it required 1 min (46-69 sec) to remove and freeze either the light-or dark-adapted eyes. All eyes were stored at -70°until sectioned. Tangential sections (6 ,m) of the retinas were cut at -20°and dried at -400 under reduced pressure. Sections were taken from the paracentral regions of the retina, and care was taken to avoid that portion underlying the myelinated fiber bundle. Paracentral areas of rabbit retina are poorly vacularized (9). Samples (0.03-0.9 ,g dry weight) were dissected from the individual retinal layers and weighed on a quartz-fiber balance (10). Stained, undissected retinal sections were used to help identify individual layers.Assay of cGMP and cAMP. The procedures used for extraction and radioimmunoas...

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“…Therefore, it is reasonable to assume that the individual terminals were depolarized at nearly equal membrane potential levels and little leakage current flowed between rods. Thus, the transretinal current was effective in stimulating rods (TRIFONOV, 1968;BYzov and TRIFONOV,1968).…”

Section: Discussionmentioning

confidence: 99%

Electrically evoked calcium responses in rods of the frog retina.

1984

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In the rod of the isolated frog retina perfused with normal Ringer solution, a transretinal current pulse flowing from the receptor side to the vitreous side evoked a response consisting of a transient depolarization and a subsequent damped oscillation. The transient depolarization was not an all-or-none response, but was a graded one which depended on the intensity and duration of the electrical stimulation. The amplitude of the initial depolarization varied with Ca2+ concentrations of the perfusate, being enhanced in the high Ca2+ and reduced in the low Ca2+ medium. Furthermore, it was enhanced by perfusion with a Bat-containing solution, and suppressed by exposure to Co2+ These observations suggest that the initial depolarization can be attributed to an increase of Ca2+ conductance. The late hyperpolarization which followed the initial depolarization was suppressed by membrane depolarization and was enhanced by membrane hyperpolarization. In addition, the evoked responses were not affected by application of either L-aspartate or L-glutamate, both of which blocked the synaptic transmission from the photoreceptors to the second order neurons. Thus it is unlikely that the late hyperpolarization is an IPSP-like response evoked by the negative feedback input from horizontal cells. Rather the rod membrane itself seems to have an oscillatory property.

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The response to electric stimulation of horizontal cells in the carp retina

Cited by 87 publications

References 1 publication

GABA-mediated negative feedback from horizontal cells to cones in carp retina.

GABA-mediated negative feedback from horizontal cells to cones in carp retina.

Distribution of 3':5'-cyclic AMP and 3':5'-cyclic GMP in rabbit retina in vivo: selective effects of dark and light adaptation and ischemia.

Electrically evoked calcium responses in rods of the frog retina.

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