Myelin loss and mild microgliosis in the cortex. (A-D) Double immunolabeling of myelin (MBP, red) and activated microglia (MAC-3, green) or microglia (F4/80, green), respectively. Cortical demyelination was detected in a subset of Nestin-Pex5
−/− mice at six weeks (B and D), but a strong microglial reaction was never seen (B and D). However, the observed microglial cells were MAC-3 positive, which indicates phagocytotic activity (B) and some microglia seem to contain myelin (D, arrow). (E-F) Loss of axons, represented as a decreased SMI31 immunoreactivity, was clearly detectable in the cortex of 12-week-old knockout mice (F), when compared to the control mice (E). All panels of each row were stained with the same antibodies. Scale bars: A-C and G-I: 100 μm; D-F: 25 μm. MBP, myelin basic protein.