Fig. 3

Microglial depletion results in greater vascular leak during CMH. a Frozen brain sections taken from mice fed normal chow or PLX5622-containing chow and maintained under normoxic conditions for 7 days were stained for the microglial marker Mac-1 (AlexaFluor-488) and DAPI. b Quantification of microglial depletion after 7 days PLX5622 in the brainstem (BS), olfactory bulb (OB), cerebral cortex (CX) and cerebellum (CB). Results are expressed as the mean ± SEM (n = 4 mice/group). **p < 0.01. Note that 7 days PLX5622 reduced microglial density in all brain regions examined to less than 10% of untreated controls. c Images of brainstem taken from mice fed normal chow or PLX5622-containing chow and maintained under hypoxic conditions for 7 days stained for CD31 (AlexaFluor-488) and fibrinogen (Cy-3). d, f Quantification of the number of leaky vessels/FOV (d) or total area of vascular leak/FOV (f) in the brainstem (BS), olfactory bulb (OB), cerebral cortex (CX) and cerebellum (CB) in mice fed normal chow or PLX5622-containing chow and maintained under hypoxic conditions for 7 days. Results are expressed as the mean ± SEM (n = 4 mice/group). *p < 0.05. Note that all regions of brain examined in PLX5622-treated mice showed a much higher number of leaky blood vessels. e 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 = 100 μm (a, c) and 50 μm (e)