%0 Journal Article
%A Groschup, Bernhard
%A Calandra, Gian-Marco
%A Raitmayr, Constanze
%A Shrouder, Joshua
%A Llovera, Gemma
%A Zaki, Asal Ghaffari
%A Burgstaller, Sandra
%A Bischof, Helmut
%A Eroglu, Emrah
%A Liesz, Arthur
%A Malli, Roland
%A Filser, Severin
%A Plesnila, Nikolaus
%T Probing intracellular potassium dynamics in neurons with the genetically encoded sensor lc-LysM GEPII 1.0 in vitro and in vivo.
%J Scientific reports
%V 14
%N 1
%@ 2045-2322
%C [London]
%I Macmillan Publishers Limited, part of Springer Nature
%M DZNE-2024-00767
%P 13753
%D 2024
%X Neuronal activity is accompanied by a net outflow of potassium ions (K+) from the intra- to the extracellular space. While extracellular [K+] changes during neuronal activity are well characterized, intracellular dynamics have been less well investigated due to lack of respective probes. In the current study we characterized the FRET-based K+ biosensor lc-LysM GEPII 1.0 for its capacity to measure intracellular [K+] changes in primary cultured neurons and in mouse cortical neurons in vivo. We found that lc-LysM GEPII 1.0 can resolve neuronal [K+] decreases in vitro during seizure-like and intense optogenetically evoked activity. [K+] changes during single action potentials could not be recorded. We confirmed these findings in vivo by expressing lc-LysM GEPII 1.0 in mouse cortical neurons and performing 2-photon fluorescence lifetime imaging. We observed an increase in the fluorescence lifetime of lc-LysM GEPII 1.0 during periinfarct depolarizations, which indicates a decrease in intracellular neuronal [K+]. Our findings suggest that lc-LysM GEPII 1.0 can be used to measure large changes in [K+] in neurons in vitro and in vivo but requires optimization to resolve smaller changes as observed during single action potentials.
%K Animals
%K Potassium: metabolism
%K Neurons: metabolism
%K Mice
%K Biosensing Techniques: methods
%K Action Potentials
%K Cells, Cultured
%K Fluorescence Resonance Energy Transfer: methods
%K Optogenetics: methods
%K Potassium (NLM Chemicals)
%F PUB:(DE-HGF)16
%9 Journal Article
%$ pmid:38877089
%2 pmc:PMC11178854
%R 10.1038/s41598-024-62993-1
%U https://pub.dzne.de/record/270295