Fig 2: Representative micrographs from double fluorescence labeling of myelin basic protein (MBP) and endothelial STL-binding sites 1 day after focal ischemia in the affected striatum of 3-month-old (B–D) as well as 12-month-old mice (A), visualized by confocal laser-scanning microscopy. MBP-immunodetection revealed an increased signal toward the ischemic zone (upper part of A, left part of B). Inter-hemispheric comparison demonstrated the nearly absent immunoreactivity of MBP (C) while vessels were clearly visible as detected by STL (C) on the contralateral, non-affected hemisphere. The same striatal region on the ischemia-affected hemisphere exhibited a dense network of MBP-positive structures (C') in close regional association to the vasculature (inset in C'). At higher magnifications, densely packed fiber-like structures of MBP were regularly observed in the ischemia-affected striatum (D'), while the contralateral striatum was devoid of these MBP-positive structures (D). Scale bars: (A) = 75 µm, (B) = 100 µm, (C,C') = 100 µm, (D,D') = 50 µm.

Fig 3: Representative forebrain overview scans from immunolabeled myelin basic protein (MBP) 1 day after focal cerebral ischemia in 3-month-old (A) and a 12-month-old mice (B). The enhanced MBP-immunosignal captured the overall territory of the middle cerebral artery (i.e., the ischemia-affected striatum, some thalamic regions and lateral parts of the neocortex), which was occluded by a filament-based model of focal cerebral ischemia. Higher magnification (inset in B) indicated dense packages of MBP-immunopositive structures (arrows with plain lines) predominantly in subcortical regions and – toward cortical areas – groups of MBP-positive, mostly parallel arranged strands (arrows with dashed lines). Scale bars: (A,B) = 1 mm.

Fig 4: Representative ischemia-related alterations of oligodendrocyte structures and the vasculature in the striatum 1 day after experimental focal cerebral ischemia in 3-month-old (C) as well as in 12-month old mice (A,B), captured by laser scanning microscopy. Concomitant fluorescence staining of the oligodendrocyte-specific protein (OSP, A) and the myelin basic protein (MBP, A') as myelin-associated markers exhibited a dense network of dotted and strand-like structures, which appeared visually enhanced due to ischemia. Immunoreactivity of the neuron-glia antigen-2 (NG2) was nearly absent in these tissues (B), while simultaneous detection with MBP clearly showed enhancement of the MBP in the same region (B'). Endogenous serum albumin was found in ischemia-affected areas (C) indicating impaired blood – brain barrier integrity, while visualization of the vasculature by collagen IV (Coll IV)-immunostaining (C') and detection of Solanum tuberosum lectin (STL)-binding sites (C?) appeared robustly with a wide range of overlapping vascular structures (C?'). Scale bars: A' (also valid for A) = 50 µm, B' (also valid for B) = 50 µm, C?' (also valid for C–C?) = 25 µm.

Fig 5: Representative micrographs of a 12-month-old mice 1 day after focal cerebral ischemia demonstrating triple fluorescence labeling of the oligodendrocyte-specific protein (OSP), myelin basic protein (MBP), and 2',3'-cyclic nucleotide-3'-phosphodiesterase (CNPase). Immunoreactivities for OSP and MBP were enhanced in the ischemic striatum (right part in A and A') and the lateral neocortex (B,B'). In a similar manner, the immunosignal of CNPase appeared to be enhanced in the ischemic striatum (right part in A?) too, which became even clearer when merging the staining pattern (A?'). Further, an enhanced CNPase-immunoreactivity appeared in the ischemia-affected neocortex except for upper neocortical layers (upper left corner in B?), while overlaying structures were predominantly identified in the affected neocortex (middle part of B?'). Scale bars: A? (also valid for A and A') = 100 µm, A?' = 50 µm, B? (also valid for B and B') = 100 µm, B?' = 50 µm.