Fig. 4

White matter localization and oligodendrocyte expression of BIN1 in the human brain. a Immunohistochemical staining of the hippocampus and parahippocampal gyrus using goat pAb N-19 (top) and mAb 2 F11 (bottom) reveal prominent white matter labeling. In the hippocampus, the perforant path axons and the alveus are labeled. b Higher magnification images of N-19 shows relatively weaker labeling in the cortex and intense labeling in the white matter. Note the labeling of mature oligodendrocytes (white arrows) in the enlarged area. c Higher magnification of mAb 2 F11 labeling reveals intense BIN1 labeling of smaller cells with a radial morphology and ramified processes (red arrows), and only a weak labeling of larger neuronal cell bodies (black arrows). In addition punctate and discontinuous staining along fine linear processes is also visible. d TPPP immunolabeling identifies mature oligodendrocytes in cerebral peduncle (red arrows). Analysis of adjacent serial sections reveal BIN1 labeling of mature oligodendrocytes and traversing myelinated fibers. e, f Immunohistochemical analysis of adjacent sections of hippocampal CA1 region reveals that the BIN1 cellular labeling pattern is distinct from that of microglia (Iba1) and astrocytes (GFAP). g Two-color immunostaining of BIN1 and Caspr. The inset shows a magnified area where the localization of BIN1 (brown) and Caspr (red) along adjacent segments of the axon tracts can be seen. BIN1 immunolabeling of annular structures likely represents cross sections of myelinated axons that lie perpendicular to the plane of the section. WM = white matter; Alv = alveus; Hipp = hippocampus; EC = entorhinal cortex; F = fimbria; DG = dentate gyrus; Sub = subiculum; PP = perforant path; CA1 = Cornu Ammonis area 1