Fig. 3

C1q neutralisation attenuates injury in a novel mouse model of AMAN. a Tidal volume and respiratory rate decreased compared to baseline measurements in both treatment groups. Tidal volume and respiratory rate reached a significant reduction in mice treated with isotype control mAb (p < 0.01, p < 0.05, respectively) compared to anti-C1q antibody (n = 5/group). Representative flow-charts from the plethysmography recordings are shown for each treatment group at baseline and 6 h post-NHS treatment. b Behavioural tests showed isotype control mAb treated mice (n = 5) spent significantly less time on the accelerating rotarod than did mice treated with anti-C1q antibody (p < 0.001). There was no significant difference in grip strength between groups. c Top panels: Illustrative images show MAC (orange) and C3c (green) deposited at nerve terminals (nAChR’s identified by α-BTx, red; CFP-positive axons, blue) from mice treated with control mAb, while this staining is absent from those treated with anti-C1q antibody. Lower panels: Anti-ganglioside antibody (orange) is present at terminals from both treatment groups, but neurofilament immunostaining (green) is only present at those terminals from mice treated with anti-C1q antibody. d The diaphragm nerve terminals were identified by fluorescently labelled α-BTx. Nerve terminals were immunohistochemically assessed for complement deposits and axonal integrity. The early and end-stage complement products C3c and MAC, respectively, showed significantly greater deposits at control mAb treated mice than anti-C1q antibody treated mice nerve terminals (p < 0.01). Axonal integrity was a measure of percentage “normal” neurofilament immunostaining overlying the endplate. Axonal integrity was significantly more intact at anti-C1q antibody protected mice nerve terminals compared to the isotype control mAb group. Box and whisker plots represent the spread of all data points and significance was based on Mann–Whitney statistical analysis of the median from each animal per treatment. * p < 0.05; ** p < 0.01; *** p < 0.001, unpaired student t-test (a,b), Mann–Whitney test (c). Scale bar = 20 μm. AGAb = anti-ganglioside antibody, nAChR = nicotinic acetylcholine receptor