Vacuolation and PrPd immunolabelling in the solitary tract nucleus of classical and atypical BSE cases. a-c) Haematoxylin and eosin (H&E) stained sections. d-f) Sections immunolabelled with monoclonal antibody (mAb) R145. Comparison of a C-type BSE case (intracerebrally inoculated case 163/95; a and d) with an L-type BSE case (L3; b and e) and an H-type BSE case (H1; c and f). In all three cases vacuolation is present, and immunolabelling is extensive and presents with particulate neuropil labelling as the predominant form.