Fig. 1

Mid-thoracic SCI alters gene expression and protein levels of molecules associated with axonal sprouting. a Experimental setup. b Schematic representation of the impact of a thoracic SCI in the sprouting of postganglionic neurons innervating the spleen. Created with BioRender.com. c–f Expression analysis of repulsive (c) and growth-associated (d–f) genes by qPCR in spleens harvested 1 h, 6 h, 24 h, and 15 days post-injury. Expression analysis was normalized to three housekeeping genes: Gapdh, Hprt, and 18s, and variation to respective time-point sham control is shown. Results were pooled from two independent experiments. N (1 h) = 5; n (6 h) = 5; n (24 h) = 5; n (15 days) = 5. g–i Immunohistochemistry of TH+ positive fibers in the spleen at 1 (g) and 15 dpi (h). Scale 50 μm. i Area occupied by sympathetic fibers (TH+) in the spleen was quantified by positive TH immunostaining relative to respective time-point sham control. N (1 day) = 2; n (15 days) = 2. j, k Western blot analysis of TH (j) and βIII-tubulin (k) in the spleen harvested 1 and 15 days post-injury (dpi). Protein analysis was normalized for the housekeeping protein actin, and variation to respective time-point sham control is shown. Data representative of three independent experiments. N (1 day) = 5; n (15 days) = 6. Statistical tests: c–f one-way ANOVA; post-hoc Tukey’s multiple comparisons test. i, j, and k unpaired t test. Results expressed as mean ± SEM. *p < 0.05; **p < 0.01, and ***p < 0.001