Fig. 3

Exosomes isolated from LPS-treated mice increase microglial activation. a Photomicrographs of the hippocampal (Hp) and neocortical (Cx) areas from C57BL/6J mice. Mice were either left untreated (Unt) or intravenously injected 1 mg of exosomes (in 200 μl PBS) isolated from the sera of donor mice. Donors received intraperitoneal injection of PBS or treatment of one of the three LPS regimens. The recipient mice were euthanized after 24 h. Brain sections were stained with anti-Iba1 antibody for microglia (red) and with DAPI for nuclei (blue). Scale bar, 20 μm. b, c Comparison of the relative immunofluorescent intensity of Iba1 in the hippocampal (b) and neocortical (c) areas between treatments. n = 3–5 per group. Data represent mean ± SEM; ns no statistical significance, *P < 0.05, **P < 0.01, and ***P < 0.001; ^#P < 0.05, ^##P < 0.01, and ^###P < 0.001 as compared to the PBS-Exo-treated group