Figure 5.

Treatment with 4Ig reduces neuronal damage after MCAO. Animals were submitted to MCAO and treated with PBS (control) or 4Ig (10 mg/kg, tail vein injection). One week after insult, brains were sectioned and neuronal damage was assessed. (a) Fluoro-Jade B labeling (green) of degenerating neurons revealed a higher number of damaged neurons in control versus 4Ig-treated animals. (b) Quantification indicated that the number of Fluoro-Jade-positive cells was significantly lower in 4Ig-treated brains when compared with controls (*P<0.01). (c) Fluorescence micrographs of peri-infarct area of the injured hemisphere. Columns (left to right) show NF-200 (NF-H) immunoreactivity with indications of the penumbra and core infarct, a merge of the preceding image with DAPI, and a higher magnification view of the inset white box in the merged images. Control samples showed sparse neurofilament immunoreactivity, whereas samples treated with the 4Ig peptide showed increased levels of NF-200 after MCAO. (d) Quantification of the relative mean number of NF-200-positive cells per mm² (±S.E.M.) following MCAO. 4Ig significantly increased the relative level of NF-200 (*P<0.01), at 7 days after stroke. Scale bar, 100 μm. (e) Representative pictures of control and 4IG treated cortical cultures following OGD and staining with DAPI or caspase-3. Bar, 100 μm. (f) Quantification of experiments presented in e showed a significant reduction of caspase-3 activation following 4Ig treatment (*P<0.01)