Nrf2 activation enhances both cytoplasmic enzyme-bound NADH and NADPH levels in basal conditions, but favours energy production in astrocytes when glucose availability is reduced.(A-B) Colour-coded representative images of (A) NAD(P)H fluorescence lifetime (τ bound) and (B) percentage of enzyme-bound NAD(P)H (α bound) in basal conditions and after 12h incubation in low glucose (1 mM) media or orthovanadate (OV, 30 μM). (C-F) Quantification in individual neurons and astrocytes of (C) NAD(P)H fluorescence lifetime (τ bound); (D) relative cytoplasmic enzyme-bound NADH levels; (E) relative cytoplasmic enzyme-bound NADPH levels and (F) percentage of enzyme-bound NAD(P)H (α bound) in basal conditions and after 12h incubation in low glucose (1 mM) media or orthovanadate (OV, 30 μM). Number of cells analysed is shown in brackets. Scale bar: 5 μm. Non-parametric Kruskal-Wallis ANOVA with post-hoc Dunn's test for each group, *p < 0.05, **p < 0.01, ***p < 0.0001. (For interpretation of the references to colour in this figure legend, the reader is referred to the Web version of this article.)