Figure 5.

Intrathecal administration of XPro1595 does not affect splenic corticosterone levels but does diminish the surge in NE expression and sprouting of adrenergic fibers within the spleen after SCI. a, b, Spleens were harvested 8 weeks after SCI and assessed for corticosterone (CORT) or norepinephrine (NE) levels via ELISA. Spleens from naive animals had a basal level of CORT and NE. Both T3Tx-Saline animals and T3Tx-XPro1595 exhibited a strong trend toward increased splenic CORT. T3Tx-Saline animals had greater levels of splenic NE than naive or T3Tx-XPro1595 animals. c–m, Transverse sections of spleens from naive, uninjured animals or T3Tx-Saline or -XPro1595 animals 8 weeks after SCI were immunostained for CD45 (green) to label leukocytes in white pulp regions and TH (red) to identify adrenergic fibers. Spleens from naive animals had large CD45⁺ islands (c) innervated by TH⁺ axons (d, e). T3Tx-Saline animals had smaller CD45⁺ white pulp regions than naive animals (f), that were innervated by more TH⁺ fibers (g, l, m). CD45⁺ white pulp in T3Tx-XPro1595 spleens were similar in size to naive animals and were larger than those in saline-treated animals (i, l). Moreover, TH⁺ immunostaining in white pulp in T3Tx-XPro1595 animals was similar to naive animals and was less than that in T3Tx-Saline animals (j, m). n = 4–5/group. Mean ± SEM *p < 0.05; **p < 0.01. Scale bar, 50 μm.