Fig. 4: Deletion of MCT4 in microglia leads to altered synaptic pruning in the hippocampus.

a Representative western blots of synaptic markers in hippocampal homogenate from P15 control and cKO littermates and b relative quantification, normalized to the control group. Each data point corresponds to one animal. Control: N = 3 males; N = 5 females; cKO: N = 5 males; N = 8 females. Two-tailed unpaired t test, **p(synapsin) = 0.0024; **p(VGAT) = 0.0011; *p(GluA2) = 0.0372. c Representative confocal z-stack projections and relative 3D reconstruction of synapsin- and Homer1-positive puncta in the CA1 stratum radiatum from control and cKO P15 mice. Scale bar: 2 µm and 0.3 µm in the inset. d Quantification of the total volume of synapsin-positive puncta measured in the CA1 stratum radiatum and dentate gyrus of control and cKO mice at P15, normalized to controls. Each data point corresponds to one animal. Control: N = 4 males; N = 4 females; cKO: N = 4 males; N = 2 females. Two-tailed unpaired t test, ***p = 0.0007. e Excitatory synapses quantification in the CA1 stratum radiatum of control and cKO mice at P15. Individual synapses are defined as the colocalization of the pre- and post-synaptic markers synapsin and Homer1. Each data point corresponds to one animal. Control: N = 4 males; N = 4 females; cKO: N = 4 males; N = 3 females. Two-tailed unpaired t test, *p = 0.0412. f Representative dendrites of CA1 pyramidal neurons in control and cKO mice at P15, visualized by Golgi-cox staining. Scale bar: 10 µm. g Quantification of spine density reported as absolute numbers per µm. Each data point represents one animal, as the average of n = 3–18 dendrites segments. Group size N = 3 (N = 1 male and N = 2 females per genotype). h Representative confocal z-stack projections and relative 3D surface reconstruction of IBA1-positive microglia cells, engulfing synapsin puncta within CD68-positive phagolysosomal structures, from control and cKO mice (P15, CA1 stratum radiatum). Left panel: scale bar 10 µm; Zoom-in: scale bar 3 µm. i, j Number and total volume of engulfed synapsin puncta per microglia volume unit. Two-tailed unpaired t test, ***p = 0.0001; ****p < 0.0001. Data points represent individual cells from N = 3 males and N = 4 females per genotype; n = 30 control cells, n = 42 cKO cells. b, d, e, g, i, j Data are represented as mean ± SEM. Source data are provided as a Source Data file.