Deletion of aquaporin-4 increases extracellular K(+) concentration during synaptic stimulation in mouse hippocampus.

• Autores: Nadia Nabil Haj-Yasein, Cecilie Elisabeth Bugge, Vidar Jensen, Ivar Østby, Ole P. Ottersen, Øivind Hvalby, Erlend Arnulf Nagelhus
• Localización: Brain Structure and Function, ISSN 1863-2653, ISSN-e 1863-2661, Vol. 220, Nº. 4, 2015, págs. 2469-2474
• Idioma: inglés
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• Resumen

  • The coupling between the water channel aquaporin-4 (AQP4) and K(+) transport has attracted much interest. In this study, we assessed the effect of Aqp4 deletion on activity-induced [K(+)]o changes in acute slices from hippocampus and corpus callosum of adult mice. We show that Aqp4 deletion has a layer-specific effect on [K(+)]o that precisely mirrors the known effect on extracellular volume dynamics. In CA1, the peak [K(+)]o in stratum radiatum during 20 Hz stimulation of Schaffer collateral/commissural fibers was significantly higher in Aqp4 (-/-) mice than in wild types, whereas no differences were observed throughout the [K(+)]o recovery phase. In stratum pyramidale and corpus callosum, neither peak [K(+)]o nor post-stimulus [K(+)]o recovery was affected by Aqp4 deletion. Our data suggest that AQP4 modulates [K(+)]o during synaptic stimulation through its effect on extracellular space volume.;