Fig. 3

Semi-quantitative tau severity grades and cytopathology progression in the locus coeruleus. a–e LC tau severity Grades 0–4 in rostral (a, b) and middle LC (c–e) sections. f Unstained, native neuromelanin rich LC neurons. g–j Progression of LC tau pathology from g dystrophic neurites to h–j somas filled with increasing amounts of tau. Note the spiked somatic protrusions characteristic of severe LC tangles in j. Scale bar = 100 μm