Histological vacuole scores by brain region for small ruminant scrapie in P2 Tg338 mice. Shown are the mean vacuolization scores with standard errors by Tg338 mouse brain region for scrapie isolates derived from the brain of three clinical goats and a reference sheep. Each isolate source case number is indicated to the right in each panel. Note the similar regional pattern of grey (G) and white (W) matter vacuole scores induced by goat and sheep-derived scrapie. G1, dorsal medulla nuclei; G2, cerebellar cortex of the folia including the granular layer adjacent to the fourth ventricle; G3, cortex of the superior colliculus; G4, hypothalamus; G5, thalamus; G6, hippocampus; G7, septal nuclei of the paraterminal body; G8, cerebral cortex (at the level of G4 and G5); G9, cerebral cortex (at the level of G7); W1, cerebellar white matter, W2, tegmentum; and W3, pyramidal tract.