Fig. 6
From: Sustained microglial activation in the area postrema of collagen-induced arthritis mice
Correlation of IL-1β expression level in the AP of brain with depressive behavior of CIA mice. A Experimental scheme for behavioral test. B Results of sucrose preferences test (CIA, n = 18; saline, n = 12). The preference for sucrose in the CIA group was significantly lower compared with the saline group by unpaired t-test. C mRNA expression levels of a microglial activation marker (Itgam, left panel) and cytokines (IL-1β, middle panel; TNF-α, right panel) in medulla containing the AP (CIA, n = 18; saline, n = 6). Itgam and lL-1β were significantly higher in the CIA group. D Correlation of medullary mRNA expression with sucrose preferences (CIA, n = 18; saline, n = 6). Preference for sucrose in the CIA group significantly correlated with expression of Itgam (rs = − 0.837, n = 18, p = 0.0000013; Spearman rank correlation coefficient) and IL-1β (rs = − 0.788, n = 7, p = 0.000104; Spearman rank correlation coefficient), but not TNF-α (rs = 0.195, n = 7, p = 0.438; Spearman rank correlation coefficient). There were no significant correlations between preference for sucrose in the saline group and any mRNAs evaluated. Abbreviations: AP, area postrema; CIA, collagen-induced arthritis; IL-1β, interleukin-1β; PID, post-immunization day; TNF-α, tumor necrosis factor-α