Abstract
Isolated rabbit retinas were superfused from the receptor side with a plasma-saline mixture kept at 35° C. The vitreal side was exposed to an atmosphere of humidified warm oxygen. In one study the second-order neuronal activity was suppressed with aspartate and glutamate; in another study transmission was not blocked. When all neurons were active, [K+]0 around receptors was 4.5 ± 0.4 mM in the dark. During a long (60s) exposure to light stimulus, [K+]0 dropped to 73% of the dark value and reaccumulated to 80%. At the vitreal surface, [K+]0 in the dark was 4.7 ± 0.8 mM. During the 60s light stimulus, [K+]0 increased transiently, dropped to 83% of the dark value, then increased again to 91%. A continuous decrease of [K+]0 at the vitreal surface during long light stimuli concurrent with the increase of [K+]0 around receptors would indicate that the spatial buffering capability of the Müller cells contributes to the reaccumulation of potassium. Such a decrease, however, was not detected. After the blockage of transmission, [K+]0 values did not vary significantly from those after light stimulus in unblocked preparations. In the dark, [K+]0 was 5.2 ± 0.9mM at the vitreal surface and 4.6 ± 0.4 mM around the receptors.
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References
Tomita T. Electrophysiological studies of retinal cell function. Invest Ophthalmol 1976; 15: 169–187.
Oakley II B, Green DG. Correlation of light-induced changes in extracellular potassium concentration with the c-wave of the electroretinogram. J Neurophysiol 1976; 39: 1117–1133.
Steinberg RH, Oakley II B, Niemeyer G. Light-evoked changes in [K+]0 in retina of the intact cat eye. J Neurophysiol 1980; 44: 897–921.
Oakley II B. Effects of maintained illumination upon [K+]0 in the subretinal space of the isolated retina of the toad. Vision Res 1983; 23: 1325–1337.
Hanitzsch R. The time course of the light-induced extracellular potassium change around receptors and at the vitreal surface compared with the time course of slow P III wave in the isolated rabbit retina. Physiologica Bohemoslowaca 1988; 37: 227–233.
Coles JA. Homeostasis of extracellular fluid in retinas of invertebrates and vertebrates. In: Progress in Sensory Physiology, Autumn H (ed), 1986; 105–138.
Karwoski CJ, Proenza LM. Sources and sinks of light evoked Δ [K+]0 in the vertebrate retina. Can J Physiol Pharmacol 1987; 65: 1009–1017.
Newman EA. Regulation of potassium levels by glial cells in the retina. Trends in Neurosciences 1985; 8: 156–159.
Newman EA. Distribution of potassium conductance in mammalian Müller (glial) cells. A comparative study. J Neuroscience 1987; 7: 2423–2432.
Hanitzsch R, Bomschein H. Spezielle Überlebensbedingungen für isolierte Netzhäute verschiedener Warmblüter. Experientia 1965; 21: 484.
Hanitzsch R. Dependence of the b-wave on the potassium concentration in the isolated superfused rabbit retina. Doc Ophthalmol 1981; 51: 235–240.
Hanitzsch R, Tomita T, Wagner H. A chamber preserving cellular function of the isolated rabbit retina suited for extracellular and intracellular recordings. Ophthal Res 1984; 16: 27–30.
Dick E, Miller RF, Bloomfield S. Extracellular K+ activity changes related to electroretinogram components. II. Rabbit Retina. J Gen Physiol 1985; 85: 911–931.
Hanitzsch R. Properties of mammalian slow P III - a retinal glial potential. In: Roitbak AJ (ed), Functions of Neuroglia, Metzmiereba, Tbilisi 1987.
Reichenbach A, Eberhardt W. Intracellular recordings from isolated rabbit retinal Müller (glial) cells. Pflügers Arch 1986; 407: 348–353.
Brew H, Attwell D. Electrogenic glutamate uptake is a major current carrier in the membrane of axolotl retinal glial cells. Nature 1987; 327: 707–709.
Barbour B, Brew H, Attwell D. Electrogenic glutamate uptake in glial cells is activated by intracellular potassium. Nature 1988; 335: 433–435.
Attwell D, Sarantis M. The effect of glutamate on glial cells isolated from the rabbit retina. J Physiol 1989; 415: 40 P.
Shimazaki H, Oakley II B. Reaccumulation of [K+]0 in the toad retina during maintained illumination. J Gen Physiol 1984; 84: 475–504.
Frishman LJ, Steinberg RH. Light evoked increases in [K+]0 in proximal portion of the dark-adapted cat retina. J Neurophysiol 1989; 61: 1233–43.
Sieving PA, Frishman LJ, Steinberg RH. Scotopic threshold response of proximal retina in cat. J Neurophysiol 1986; 56: 1049–1061.
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Mättig, WU., Hanitzsch, R. Changes in [K+]0 at the vitreal surface compared with those around receptors in the isolated rabbit retina. Doc Ophthalmol 75, 181–187 (1990). https://doi.org/10.1007/BF00146554
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DOI: https://doi.org/10.1007/BF00146554