%0 Journal Article
%A Gerkau, Niklas J.
%A Lerchundi, Rodrigo
%A Nelson, Joel S. E.
%A Lantermann, Marina
%A Meyer, Jan
%A Hirrlinger, Johannes
%A Rose, Christine R.
%T Relation between activity‐induced intracellular sodium transients and ATP dynamics in mouse hippocampal neurons
%J The journal of physiology
%V 597
%N 23
%@ 1469-7793
%C Hoboken, NJ
%I Wiley-Blackwell
%M FZJ-2020-01276
%P 5687 - 5705
%D 2019
%X 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. 
%F PUB:(DE-HGF)16
%9 Journal Article
%$ pmid:31549401
%U <Go to ISI:>//WOS:000493167900001
%R 10.1113/JP278658
%U https://juser.fz-juelich.de/record/874176