Figure 3. SCI Leads to Brain Choroid Plexus Activation and Monocyte Recruitment.

(A–C) Morphological changes at the CP after SCI.

(A) Cresyl violet staining; arrowheads indicate epithelial swelling, pointer indicates epithelial flattening or attenuation, and asterisk indicates ventricular flocculent material. n = 3–4 animals.

(B and C) Staining of CP for tight junctions (Zo-1 in B and occludin in C) and CD31. Arrowheads mark areas with disorganized epithelial tight junctions. n = 3 animals per time point; qualitatively similar. (Cii) qRT-PCR analysis of isolated CP for Ocln, encoding occludin. n = 3–4 per time point. ANOVA: F = 6, p = 0.03. (D–I) GFP⁺ cells in the CP of SC-injured Cx3cr1^GFP/+ chimeras.

(D–F) GFP⁺ cells in CP sections (D) or whole mounts (E and higher magnification in F). n = 3–4 mice.

(G–I) Flow cytometry analysis.

(G) Quantitative kinetics. Values are absolute cell numbers per 10,000 live cells. ANOVA: (i) F_5,12 = 3.12, p = 0.04; (ii) F_3,15 = 27.05, *p < 0.0001 relative to uninjured.

(H) Dot plot of CP (d0; chimera) for Iba-1 and GFP.

(I) Marker expression; slash indicates heterogeneity; isotype controls served as negative controls; pools of ten mice.

(J and K) CPs analyzed by (J) qRT-PCR (n = 3–4 per time point; ANOVA; *relative to uninjured) and (K) Luminex (pools of six mice; results of day 0 are presented as fold of change relative to noninjured; ANOVA; F_6,9 = 4.96, p = 0.018).

Data are represented as mean ± SEM. Scale bars represent 100 μm in (D) and (E), 50 μm in (A)–(C), and 10 μm in (F). See also Figure S2.