Fig. 1

Synaptic loss in lumbar spinal cord of TDP-43-positive ALS correlates with loss of MN but not with pTDP-43-immunopositive MN. a–d Representative pictures of lumbar SC (L4-L5) overview, a), with high-magnification insets from laminae I-II (b), lamina VII (c) and lamina IX (d) from healthy control and pTDP-43 + ALS cases with different disease duration and neuropathological stage; immunostaining for Synaptophysin, 50 µm paraffin sections. Scale bar = 500 µm overview, 20 µm inset. e–g. Synaptic area is unchanged in laminae I-II (3) in lamina VII (f); in lamina IX a significant decrease in synaptic area is observed (g; uncorrected t-test p = 0.086; t-test with Welch´s correction for different SD, p < 0.001). h. The synaptic area in lamina IX is directly correlated with the number of surviving MN (r = 0.709; p < 0.0001). i No correlation between the fraction of MN displaying pTDP-43 + inclusions and the synaptic area in lamina IX. Data information: In (e–g), data are presented as means ± SD. ns, p > 0.05 (t-test and Pearson´s and Spearman´s correlation)