Brainstem pathology is absent in K^b-/-D^b-/- BM chimeras.

(A) Representative confocal images of sagittal brain sections from a wild type BM chimera mouse (top) or a K^b-/-D^-/- BM chimera (bottom) at d6 p.i. following simultaneous i.v. injection of Evans blue (white) and propidium iodide (red) to visualize vascular leakage and cell death, respectively (n = 4 mice per group). Cell nuclei are shown in blue. (B) Representative confocal images of the brainstem from a wild type BM chimera mouse (top) or a K^b-/-D^-/- BM chimera (bottom) at d6 p.i. following propidium iodide (red) injection and immunohistochemical staining for NeuN⁺ neurons (green). Cell nuclei are shown in blue. (C) The bar graph shows quantification of data shown in (B). Each bar represents the total number of brainstem cells that are PI⁺ (gray), and within the bar, the red coloration shows the proportion that are also NeuN⁺ (mean ± SD; n = 4 mice per group; 1 brain section per mouse; 4 images per brain section). Asterisks denote a statistically significant difference from all other groups (***P < 0.05).