Fig. 2.

Microglial depletion results in exaggerated vascular leak during CMH. (A) Frozen sections of lumbar spinal cord taken from mice fed normal chow or PLX5622-containing chow and maintained under normoxic conditions for 7 d were stained for the microglial marker Mac-1. (B) Quantification of microglial depletion after 7-d PLX5622. Results are expressed as the mean ± SEM (n = 6 mice per group). Note that 7-d PLX5622 reduced the number of spinal cord microglia to 10% of untreated controls. (C and D) Frozen sections of lumbar spinal cord taken from mice fed normal chow or PLX5622-containing chow and maintained under hypoxic conditions for 7 d were stained for CD31 (Alexa Fluor 488) and fibrinogen (Cy-3). (E) Quantification of the number of leaky vessels/FOV. Results are expressed as the mean ± SEM (n = 6 mice per group). *P < 0.05, **P < 0.01. One-way ANOVA followed by Tukey’s multiple comparison test. Note that PLX5622-treated mice showed a much greater number of leaky blood vessels. (F) CD31/fibrinogen/Mac-1 triple-IF of control chow mice confirmed microglial clustering and elevated levels of Mac-1 expression by microglia surrounding the leaky vessel, but absence of microglial clustering in PLX5622-fed mice. (Scale bars, A, 100 μm; C, 50 μm; D, 100 μm; F, 25 μm.)