Multirecording of Ca(2+) signals from inner retinal neurons evoked by light stimulation of photoreceptors.
We simultaneously monitored changes of intracellular free Ca(2+) concentration ([Ca(2+)](i)) following different light stimuli from different inner retinal neurons of the turtle retina slice preparation. [Ca(2+)](i) increased with an increase of the light stimulus intensity. Some of the cells also showed color opponent Ca(2+) signals. 2-Amino-4-phosphonobutyric acid (APB) blocked in particular [Ca(2+)](i) increases and picrotoxin enhanced the observed [Ca(2+)](i) changes. These data support the idea that the observed [Ca(2+)](i) changes result from light stimulation and subsequent retinal processing. Similar Ca(2+) signals were observed when the release of Ca(2+) from internal stores was blocked with caffeine and thapsigargin. These results indicate that retinal Ca(2+) signals evoked by light stimulation depend to a large extent on voltage-dependent Ca(2+) influx and might therefore reflect signal processing.
Okada
T
T
Neurobiology, FB 7, Department of Biology, University of Oldenburg, PO Box 2503, D-26111, Oldenburg, Germany.
Weiler
R
R
D000818:Animals; D002087:Butyrates / Q000494:pharmacology; D002110:Caffeine / Q000494:pharmacology; D020013:Calcium Signaling / Q000187:drug effects / Q000502:physiology*; D000697:Central Nervous System Stimulants / Q000494:pharmacology; D004594:Electrophysiology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D006633:Histamine Antagonists / Q000494:pharmacology; D010775:Photic Stimulation; D020419:Photoreceptor Cells, Vertebrate / Q000187:drug effects / Q000502:physiology*; D010852:Picrotoxin / Q000494:pharmacology; D013194:Staining and Labeling; D019284:Thapsigargin / Q000494:pharmacology; D014426:Turtles / Q000502:physiology*
D002087:Butyrates; D002110:Caffeine; D000697:Central Nervous System Stimulants; D004791:Enzyme Inhibitors; D006633:Histamine Antagonists; D010852:Picrotoxin; D019284:Thapsigargin