Abstract
The presence of sodium-potassium-adenosine triphosphatase (Na+,K+-ATPase) on the surface of arachnoid cells indicates that active transport of electrolytes and water occurs there. Previously, we accidentally found that intraventricular administration of TGF-beta1 impaired rat spatial learning. Levels of Na+,K+ -ATPase were decreased in arachnoid cells with fibrosis. To characterize the role of the Na+,K+ -ATPase, Wistar rats were intraventricularly administered a total of 200 microl of ouabain, at concentrations of 10(-5), 10(-4) and 10(-3) M, for one week with an osmotic pump, and were examined with a Morris water maze. Latency for reaching the platform did not significantly differ between ouabain-administered rats and controls. Spatial learning was impaired in a dose-dependent manner. Na+,K+ -ATPase activity of arachnoid cells ceased during ouabain administration, and recovered completely three weeks after the end of ouabain administration. The present results suggest that the Na+,K+ -ATPase on the surface of arachnoid cells contributes to maintenance of rat spatial learning.
MeSH terms
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Animals
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Arachnoid / drug effects
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Arachnoid / enzymology*
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Arachnoid / ultrastructure
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Cell Membrane / drug effects
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Cell Membrane / enzymology
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Cell Membrane / ultrastructure
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Disease Models, Animal
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Dose-Response Relationship, Drug
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Down-Regulation / drug effects
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Down-Regulation / physiology
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Enzyme Inhibitors / pharmacology
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Epithelial Cells / drug effects
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Epithelial Cells / enzymology
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Epithelial Cells / ultrastructure
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Fibrosis / chemically induced
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Fibrosis / pathology
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Fibrosis / physiopathology
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Injections, Intraventricular
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Male
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Maze Learning / drug effects*
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Maze Learning / physiology
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Memory Disorders / chemically induced
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Memory Disorders / enzymology*
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Memory Disorders / physiopathology
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Meninges / drug effects
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Meninges / ultrastructure
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Microscopy, Electron
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Ouabain / pharmacology
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Rats
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Rats, Wistar
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Reaction Time / drug effects
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Reaction Time / physiology
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Sodium-Potassium-Exchanging ATPase / antagonists & inhibitors
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Sodium-Potassium-Exchanging ATPase / metabolism*
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Water-Electrolyte Balance / drug effects
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Water-Electrolyte Balance / physiology*
Substances
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Enzyme Inhibitors
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Ouabain
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Sodium-Potassium-Exchanging ATPase