Fig 4. Significant decline in circulating T- and B-cell frequencies after cervical SCI compared to sham-operated rats.

(a-b) T- and B-cell frequencies in rats with cervical SCI were significantly lower than in shams at 10 weeks post-injury. These frequencies did not change with time post-cervical SCI, whereas in shams T- and B- cells exhibited time-dependent changes; with (a) T- cells marking a significant increase from 2 to 10 weeks and a drop from 10 to 20 weeks, whereas (b) B- cell proportions declined from 10 to 20 weeks p.i. (c) CD8⁺ T- cell frequencies dropped at 2 weeks post cervical SCI, compared to shams, but no overall time-dependent changes were observed within each injury group. (d) CD4+ T- cells were similar between injury groups, although only CD4⁺ T- cells in sham animals showed time-dependent changes; with a significant increase from 2 to 10 weeks and a decrease from 10 to 20 weeks. For all data Independent Student’s t-tests were performed to analyze differences between sham and cervical SCI groups at each time point. Within each injury group, one-way ANOVA with Bonferroni post hoc tests between weeks was conducted to compare time-dependent changes. * p < 0.05, ** p < 0.01 (black * refers to difference between sham and SCI, blue and red * refer to time-dependent difference within the SCI or sham group following post-hoc testing, respectively); N = 5–7 (2 weeks), 6 (10 weeks), 7 (20 weeks) rats/ injury group, mean ± SEM.