Fig. 5

Lactate treatment promotes axon regeneration and locomotor function recovery after SCI in vivo. A Images of astrocytes (GFAP, green) stained with neurons (NeuN, magenta) in Zone1-Zone3 (Z1_Z3) at 28 dpi in control, lactate, 4-CIN, and OX groups in vivo. Z1 (0–250 μm) was in the lesion site, Z2 (250–500 μm) was started immediately adjacent to Z1, and Z3 (500–750 μm) was adjacent to Z2. Scale bars: magnification, 100 μm. Compass: D, dorsal; V, ventral; R, rostral; C, caudal. B Quantification of NeuN⁺ neurons in three zones (Z1_Z3) in control, lactate, 4-CIN, and OX groups. All data were presented as the mean ± SEM, n = 3 mice per group, *p < 0.05; **p < 0.01. C Images of GFAP (green) co-stained with axons (5-HT, magenta) at 28 dpi in control, lactate, 4-CIN, and OX groups in vivo, and the boxed region indicated the lesion center magnified in right panels. Asterisks indicate the lesion site, scale bars: low magnification, 100 μm; high magnification, 20 μm. C Quantification of the percentage of 5-HT⁺ area in the area of the spinal cord segment penetrating into the lesion core at 28 dpi in vivo. All data are presented as the mean ± SEM, n = 3 mice per group, *p < 0.05; ***p < 0.001; N.S., not significant. D Schedule of locomotor function analysis and the intraperitoneal injection with lactate, 4-CIN or OX daily until 28 dpi. E Locomotor function was evaluated by BMS at the indicated time points. All data are presented as the mean ± SEM, n = 8 mice per group, *p < 0.05; ***p < 0.001; ****p < 0.0001. F Representative images of footprint analysis in control, lactate, 4-CIN, and OX groups at 28 dpi. H–J Quantification of the stride length and width and paw rotation at 28 dpi. All data are presented as the mean ± SEM, n = 8 mice per group; *p < 0.05; **p < 0.01; ***p < 0.001; ****p < 0.0001; N.S., not significant