Fig. 3

Anti-phosphorylated α-synuclein reactivity in the anterior olfactory nucleus. A Example of immunohistochemical staining for p-αSyn in the human olfactory bulb, highlighting the AON from a person with Parkinson disease and related dementia [case #39]. Scale bars represent 100 µM. B Representative images of semi-quantitative scoring of pathology, ranging from 0 to 5, in the AON. Scale bars represent 50 µM. C Percentage of cases in each group that have a pathology score of 1 or higher. D Correlation between age and p-αSyn pathology scores in the control group (HCO and NCO combined) and COVID19 + cases. E Distribution of pathology scores for each group. Filled blue squares in D and E indicate COVID19 + cases suspected of having incidental LBD at autopsy; filled dark yellow diamond in E indicates AD case diagnosed with mixed pathology at autopsy, and filled green triangle indicates MSA case. Significance was determined using Kruskal–Wallis test with Dunn's post-hoc (E), where **** indicates p ≤ 0.0001. Abbreviations for disease groups as in Fig. 1