Figure 1. Incubation periods of chronic wasting disease (CWD) and neuropathologic features of CWD agent–infected squirrel monkeysA) Incubation periods for squirrel monkeys infected with CWD agents by intracerebral (IC) or oral (PO) routesSolid circles indicate euthanized squirrel monkeys (SM) that tested positive for prion diseaseThe open circle indicates 1 squirrel monkey that remained clinically normal at 108 months postinoculation (mpi)Lines indicate the mean and standard deviation within each groupB, C) Lesion profiles of CWD-agent–infected squirrel monkeys showing spongiform degeneration (B) and PrPres deposition (C) values in 10 gray matter regions of the brainN values for each group are as follows: IC SM-CWD, 11; PO SM-CWD, 7; IC control SM, 1TL, temporal lobe; PL, parietal lobe; FL, frontal lobe; OL, occipital lobe; Cer, cerebellum; Thal, thalamus; HC, hippocampus; MB, midbrain; Str, stiatum; SC, spinal cordError bars show the SD for each groupPanels D-G show brain from a squirrel monkey infected PO with CWD and euthanized at 69 months postinoculationPanels D-F are stained with hematoxylin and eosin and show D) severe spongiform lesions in the striatum, E) lack of pathology in the occipital lobe, and F) pathology in the parietal lobePanels G, H, and J show immunohistochemical staining for PrPres by using anti-PrP antibody D13G) Adjacent section to the region depicted in F shows the positive correlation of PrPres (brown) with spongiform degenerationPanels H–J show lymphoid tissue from a squirrel monkey infected PO with CWD and euthanized at 80 mpiH) PrPres (brown) staining in spleen and J) mesenteric lymph nodeI) No primary antibody control of the region shown in H, demonstrating specificity of stain observed in HThe scale bar shown in D applies to panels D–G and represents 50 µm; the scale bar shown in H applies to H–I and represents 25 µm.