TY  - JOUR
AU  - Gerkau, Niklas J.
AU  - Lerchundi, Rodrigo
AU  - Nelson, Joel S. E.
AU  - Lantermann, Marina
AU  - Meyer, Jan
AU  - Hirrlinger, Johannes
AU  - Rose, Christine R.
TI  - Relation between activity‐induced intracellular sodium transients and ATP dynamics in mouse hippocampal neurons
JO  - The journal of physiology
VL  - 597
IS  - 23
SN  - 1469-7793
CY  - Hoboken, NJ
PB  - Wiley-Blackwell
M1  - FZJ-2020-01276
SP  - 5687 - 5705
PY  - 2019
AB  - Excitatory neuronal activity results in the influx of Na+ through voltage‐ and ligand‐gated channels. Recovery from accompanying increases in intracellular Na+ concentrations ([Na+]i) is mainly mediated by the Na+/K+‐ATPase (NKA) and is one of the major energy‐consuming processes in the brain. Here, we analysed the relation between different patterns of activity‐induced [Na+]i signalling and ATP in mouse hippocampal CA1 pyramidal neurons by Na+ imaging with sodium‐binding benzofurane isophthalate (SBFI) and employing the genetically encoded nanosensor ATeam1.03YEMK (ATeam). In situ calibrations demonstrated a sigmoidal dependence of the ATeam Förster resonance energy transfer ratio on the intracellular ATP concentration ([ATP]i) with an apparent KD of 2.6 mm, indicating its suitability for [ATP]i measurement. Induction of recurrent network activity resulted in global [Na+]i oscillations with amplitudes of ∼10 mm, encompassing somata and dendrites. These were accompanied by a steady decline in [ATP]i by 0.3–0.4 mm in both compartments. Global [Na+]i transients, induced by afferent fibre stimulation or bath application of glutamate, caused delayed, transient decreases in [ATP]i as well. Brief focal glutamate application that evoked transient local Na+ influx into a dendrite, however, did not result in a measurable reduction in [ATP]i. Our results suggest that ATP consumption by the NKA following global [Na+]i transients temporarily overrides its availability, causing a decrease in [ATP]i. Locally restricted Na+ transients, however, do not result in detectable changes in local [ATP]i, suggesting that ATP production, together with rapid intracellular diffusion of both ATP and Na+ from and to unstimulated neighbouring regions, counteracts a local energy shortage under these conditions. 
LB  - PUB:(DE-HGF)16
C6  - pmid:31549401
UR  - <Go to ISI:>//WOS:000493167900001
DO  - DOI:10.1113/JP278658
UR  - https://juser.fz-juelich.de/record/874176
ER  -