Figure 5.

Acute neuronal degeneration and cell loss in LGI1 antibody-positive FEPSO animals. Staining for terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) (blue) and MAP2/neuronal nuclei (NeuN) (red). (A) TUNEL⁺ cells and severe loss of neurons and processes is visible in the hippocampus. (B) Shows the areas indicated by the rectangle in Figure 5A, revealing TUNEL⁺ neurons and loss of myelin-associated protein 2 reactivity (arrowheads). (C) In the amygdala, a high number of TUNEL⁺ nuclei are visible, while in (D), enlargement of rectangle in Figure 5C and loss of MAP2-reactivity around TUNEL + nuclei is observed. Neither in the (E) basal ganglia, (F) cortex, (G) cerebellum nor (H) white matter TUNEL⁺ cells or de-hypomyelination was observed. (I) The percentage of TUNEL⁺ cells in different areas was quantified. This graph shows significant cell loss in the hippocampus of FEPSO animals. Data are shown as median with interquartile range, LGI1 antibody-positive animals are indicated in red, and untested animals in black (***p < 0.001, Kruskal–Wallis test with Dunn’s post hoc correction, hippocampus n = 15, amygdala n = 9, basal ganglia n = 12, cortex n = 15, cerebellum n = 13). (J) Hippocampal cornu ammonis (CA) subfields revealed severe loss of NeuN-positive cells compared with normal controls (equals 100%) in CA1-4, but not in DG. CA4 subfields exhibits reveal the most severe cell losses, which was significantly different from the loss in the DG. Data shown as median with interquartile range (***p < 0.001, Wilcoxon signed-rank test with hypothetical value: 100, n = 14, **p < 0.01, Kruskal–Wallis test with Dunn’s post hoc correction for evaluation of inter-hippocampal differences, n = 14). Scale bar corresponds to (A) 200 µm, (B,D) 20 µm, (C) 100 µm, (E,F,H) 50 µm, and (G) 200 µm.