Fig. 2

Histopathology and immunohistochemistry of the index US GH-CJD patient. a-h: Histopathology. a-c: Spongiform degeneration (SD) selectively affecting the deeper layers of the cingulate gyrus (a; bracket), the hippocampal gyrus (b) and more severely the basal ganglia (c). c-d: Reactive astrogliosis (circles) in basal ganglia (c) and midbrain substantia nigra (d); arrows in the inset (dashed square) indicate intraneuronal vacuole formation. e: A kuru plaque in the frontal cortex reminiscent of the florid plaques observed in vCJD. f: A different type of plaque, apparently core-free, was detected in the cortical (f, parietal cortex) and subcortical brain regions. (not shown) g: A ballooned neuron. h: Kuru plaques (arrows) in the cerebellar granular layer. i-q: Immunohistochemistry. i: Laminar PrP immunostaining of the insula. j: Kuru plaque (circles) and plaque-like (squares) PrP immunostaining in the cerebellar granular and molecular layers, and peri-cellular PrP (“stellate”) (arrow) in the molecular layer. k: Large PrP aggregates (circle) and peri-cellular PrP immunostaining (“stellate” cells) (arrow) in proximity of one sulcus in the frontal cortex (dotted line delimiting the sulcus). i: Intense PrP immunostaining of the hippocampus. m: “Brush stroke-like” PrP immunostaining in the molecular layer of the cerebellum. n-o: Higher magnification of the PrP-immunostained “stellate” cells in the cerebellar molecular layer of the present case (n) and in one vCJD case (o). p-q: Intense PrP staining of the dentate nucleus (p) and along processes around the perikaryon of a neuron of the frontal cortex (q). Scale bar of inset in d: 50 μm; antibody: 3F4