Atypical bovine spongiform encephalopathy (BSE) has recently been identified in Europe, North America, and Japan. It is classified as H-type and L-type BSE according to the molecular mass of the disease-associated prion protein (PrPSc). To investigate the topographical distribution and deposition patterns of immunolabelled PrPSc, H-type BSE isolate was inoculated intracerebrally into cattle. H-type BSE was successfully transmitted to 3 calves, with incubation periods between 500 and 600 days. Moderate to severe spongiform changes were detected in the cerebral and cerebellar cortices, basal ganglia, thalamus, and brainstem. H-type BSE was characterized by the presence of PrP-immunopositive amyloid plaques in the white matter of the cerebrum, basal ganglia, and thalamus. Moreover, intraglial-type immunolabelled PrPSc was prominent throughout the brain. Stellate-type immunolabelled PrPSc was conspicuous in the gray matter of the cerebral cortex, basal ganglia, and thalamus but not in the brainstem. In addition, PrPSc accumulation was detected in peripheral nervous tissues such as the trigeminal ganglia, dorsal root ganglia, optic nerve, retina, and neurohypophysis. Cattle are susceptible to H-type BSE with a shorter incubation period, showing distinct and distinguishable phenotypes of PrPSc accumulation.
(Prion Disease Research Center)
References:
Okada H. et al (2011) Vet. Res. 42:79 (DOI: 10.1186/1297-9716-42-79)
