Fig. 2

Surgery induced neuroinflammation by triggering the peripheral inflammatory response. The concentration of a HMGB1, b IL-1β, c IL-6, and d TNF-α in serum were measured using ELISAs on postoperative days 1, 3, 6, 13, and 20 (n = 5 rats per group). e Representative immunoblot showing the levels of the HMGB1 protein (top panel) and densitometry analysis of the HMGB1 protein (bottom panel) in the dHPC on postoperative days 1, 3, 6, 13, and 20 (n = 5 rats per group). f Representative confocal images of immunohistochemical staining for HMGB1⁺ cells (green) in the dHPC captured with a 10 × objective on postoperative day 3. The concentration of g IL-1β, h IL-6, and i TNF-α in the dHPC were measured using ELISAs on postoperative days 1, 3, 6, 13, and 20 (n = 5 rats per group). j Representative confocal images of immunohistochemical staining for Iba1⁺ cells (red) in the dHPC captured with a 10 × objective on postoperative days 1 and 3. k Quantitative analysis of Iba1⁺ cells in the dHPC on postoperative days 1, 3, 6, 13, and 20 (n = 5 rats per group). l Representative 2D projection images of microglia captured with a 63 × objective (left panel). A schematic diagram of a 2D Sholl grid of concentric spheres beginning from the geometric center of the microglial cell soma (middle panel). Quantitative Sholl analysis of microglial processes by counting the number of intersections (right panel). m Total process lengths and n cell body area observed in confocal images of immunohistochemical staining for microglia were analyzed using FIJI software (n = 96 microglial cells from 4 rats per group). C control, S surgery. Data are presented as means ± SEM and statistical analyzed by a two-way ANOVA followed by a Tukey’s test (a, b, c, d, e, g, h, i, and k), or a Student’s t test (l, m, and n). *p < 0.05 and **p < 0.01 compared with Control