TY  - JOUR
AU  - Groschup, Bernhard
AU  - Calandra, Gian-Marco
AU  - Raitmayr, Constanze
AU  - Shrouder, Joshua
AU  - Llovera, Gemma
AU  - Zaki, Asal Ghaffari
AU  - Burgstaller, Sandra
AU  - Bischof, Helmut
AU  - Eroglu, Emrah
AU  - Liesz, Arthur
AU  - Malli, Roland
AU  - Filser, Severin
AU  - Plesnila, Nikolaus
TI  - Probing intracellular potassium dynamics in neurons with the genetically encoded sensor lc-LysM GEPII 1.0 in vitro and in vivo.
JO  - Scientific reports
VL  - 14
IS  - 1
SN  - 2045-2322
CY  - [London]
PB  - Macmillan Publishers Limited, part of Springer Nature
M1  - DZNE-2024-00767
SP  - 13753
PY  - 2024
AB  - 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.
KW  - Animals
KW  - Potassium: metabolism
KW  - Neurons: metabolism
KW  - Mice
KW  - Biosensing Techniques: methods
KW  - Action Potentials
KW  - Cells, Cultured
KW  - Fluorescence Resonance Energy Transfer: methods
KW  - Optogenetics: methods
KW  - Potassium (NLM Chemicals)
LB  - PUB:(DE-HGF)16
C6  - pmid:38877089
C2  - pmc:PMC11178854
DO  - DOI:10.1038/s41598-024-62993-1
UR  - https://pub.dzne.de/record/270295
ER  -