1. NMDA receptor-mediated K+ efflux and neuronal apoptosis.
- Author
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Yu SP, Yeh C, Strasser U, Tian M, and Choi DW
- Subjects
- Animals, Calcium metabolism, Calcium pharmacology, Calcium Channels metabolism, Cells, Cultured, Cerebral Cortex metabolism, Culture Techniques, Glutamic Acid metabolism, Ion Channel Gating, Ion Transport, Membrane Potentials, Mice, N-Methylaspartate pharmacology, Neocortex cytology, Neocortex embryology, Neocortex metabolism, Neurons metabolism, Patch-Clamp Techniques, Sodium metabolism, Sodium pharmacology, Apoptosis, Cerebral Cortex cytology, Neurons cytology, Potassium metabolism, Receptors, N-Methyl-D-Aspartate metabolism
- Abstract
Neuronal death induced by activating N-methyl-D-aspartate (NMDA) receptors has been linked to Ca2+ and Na+ influx through associated channels. Whole-cell recording from cultured mouse cortical neurons revealed a NMDA-evoked outward current, INMDA-K, carried by K+ efflux at membrane potentials positive to -86 millivolts. Cortical neurons exposed to NMDA in medium containing reduced Na+ and Ca2+ (as found in ischemic brain tissue) lost substantial intracellular K+ and underwent apoptosis. Both K+ loss and apoptosis were attenuated by increasing extracellular K+, even when voltage-gated Ca2+ channels were blocked. Thus NMDA receptor-mediated K+ efflux may contribute to neuronal apoptosis after brain ischemia.
- Published
- 1999
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