fig. 5

α2-Na⁺/K⁺-ATPase knockdown or ouabain reduced K⁺ uptake during whisker stimulation. In order to investigate the extracellular potassium changes, a fluorescent potassium probe, Asante Potassium Green-4 (IPG-4) was used. A The potassium sensitivity of IPG-4 fluorescence was linear within the range encountered in the extracellular space during CSD as assessed in vitro. B and C We monitored the extracellular potassium changes through a cranial window placed over the barrel cortex (picture) by plotting the relative fluorescence intensity change (dF/F0) over time (graphs on the left) and calculating the area under the curve (bars on the right). In ouabain-primed (0.1 mM) cortex, 5 min of 10 Hz whisker stimulation resulted in a significant increase in potassium fluorescence compared to aCSF-treated control group (n = 6 mice for each group)(p = 0.004, Mann–Whitney U test). Similarly, there was significant increase in potassium signal during whisker stimulation in α2-Na⁺/K⁺-ATPase shRNA-encoding plasmid injected mice (n = 5) compared to blank plasmid injected animals (n = 6)(p = 0.055, Mann–Whitney U test). Error bars represent SEM