Figure 3. Splenectomy did not influence myelopoiesis, monocyte redistribution, or the establishment of anxiety-like behavior following initial exposure to RSD.

A) Male C57BL/6 mice were subjected to sham or splenectomy (SPLX) surgery and were allowed to recover for 14 days. Mice were then exposed to repeated social defeat (RSD) or left undisturbed as controls (CON), and 14 hrs after the final cycle, anxiety-like behavior was assessed in the open field. Subsequently, brain, blood, and bone marrow were collected for analysis. B) RSD increased spleen weight in sham mice (p<0.05). Spleen weights were not detectable (n.d.) in splenectomized mice. C) Representative flow Bi-variate dot plots of CD31 and Ly6C labeling on bone marrow cells is shown. D) Independent of splenectomy, RSD decreased erythrocytes (F_1,17=124.5, p<0.0001) and lymphocytes (F_1,17=129.2, p<0.01) and increased monocytes (F_1,17=120.0, p<0.0001) and granulocytes (F_1,17=144.9, p<0.0001) in bone marrow. E) RSD increased percent Ly6C^hi monocytes in circulation independent of splenoctomy (F_1,18=12.0, p<0.01). F) Representative flow Bi-variate dot plots of CD11b and CD45 labeling on enriched brain macrophages (MΦ) and microglia (MGL). G) RSD increased percent brain macrophages (F_1,18=10.4, p<0.01). RSD increased anxiety-like behavior in the open field with increased time to enter the center (H; F_1,23=8.2, p<0. 01) and decreased time spent in the center (I; F_1,23=10.2 p<0. 01). Abbreviations: Mo, Monocytes; Gr, Granulocytes; Ly, Lymphocytes; Er, Erythrocytes. Bars represent the mean ± SEM. Means with asterisk (*) are significantly different from CON (p<0.05) and means with (#) tended to be different from CON (p<0.1), according to F-protected post hoc analysis.