K+ waves in brain cortex visualized using a long-wavelength K+-sensing fluorescent indicator.

Prashant Padmawar; Xiaoming Yao; Orin Bloch; Geoffrey T Manley; A S Verkman

doi:10.1038/nmeth801

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K+ waves in brain cortex visualized using a long-wavelength K+-sensing fluorescent indicator.

Prashant Padmawar·Xiaoming Yao·Orin Bloch·Geoffrey T Manley·A S Verkman

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Abstract

We synthesized a water-soluble, long-wavelength K(+) sensor, TAC-Red, consisting of triazacryptand coupled to 3,6-bis(dimethylamino)xanthylium, whose fluorescence increased 14-fold at 0-50 mM K(+) with K(+)-to-Na(+) selectivity >30. We visualized K(+) waves in TAC-Red-stained brain cortex in mice during spreading depression, with velocity 4.4 +/- 0.5 mm/min, and K(+) release and reuptake half-times (t(1/2)) of 12 +/- 2 and 32 +/- 4 s, respectively. Aquaporin-4 (AQP4) deletion slowed K(+) reuptake about twofold, suggesting AQP4-dependent K(+) uptake by astroglia.

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Animals Aquaporin 4 Astrocytes Aza Compounds Cerebral Cortex Fluorescent Dyes Heterocyclic Compounds, 3-Ring Mice Mice, Knockout Molecular Structure Potassium Solubility Time Factors Journal Article Research Support, N.I.H., Extramural Research Support, Non-U.S. Gov't Research Support, U.S. Gov't, P.H.S.

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Prashant Padmawar, Xiaoming Yao, Orin Bloch, Geoffrey T Manley, A S Verkman. 2005. K+ waves in brain cortex visualized using a long-wavelength K+-sensing fluorescent indicator.. https://doi.org/10.1038/nmeth801

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