Fig. 1. Microglia are metabolically flexible and can efficiently import lactate in vitro.

a Heatmaps of the microglial expression levels of genes annotated within substrate metabolism-related KEGG pathways. Data were obtained from the dataset published in Pinto et al.²⁶, from three independent experiments, shown as normalized intensity values. b Violin plot showing Seurat⁸³ module scores for six KEGG pathways across different cell types in the mechanically dissociated mouse hippocampus (dataset from Mattei et al.²⁷). The module scores represent the average expression of all genes in a particular cluster at a single-level, subtracted by the aggregated expression of control feature sets. Module scores in microglia are compared to other cell types; Two-sided Wilcoxon test, ****p < 0.0001; exact p values are provided in Supplementary Fig. 1b. c Representative confocal z-stack projections of SCOTfluor lactate internalized by primary microglia, in standard (25 mM) or reduced (0.1 mM) glucose conditions and d relative quantification. Data point represent individual cells; glucose 25 mM: n = 105 cells; glucose 0.1 mM: n = 168 cell from N = 3 independent experiments. Two-tailed unpaired t test, ****p < 0.0001. Scale bar: 50 µm. e Intracellular lactate content measured by LC-MS in primary microglia cells upon 6 h exposure to 20 mM Na-lactate or control in standard 25 mM glucose conditions. N = 3 independent experiments. Two-tailed unpaired t test, *p = 0.0235. d, e Data are represented as mean ± SEM. a, b, d, e Source data are provided as a Source Data file.