Fab fragments from some patients disrupt glycinergic neurotransmission. (A) Example electrophoresis gel stained with Ponceau S showing a protein ladder (left), the undigested IgG, digest (containing Fc and Fab fragments) and purified Fab fragments. (B) Upper panel shows example traces and example amplitude scaled average miniature events from cells incubated in Fab fragments generated from IgGs from Control Subject 2 and Patients 1–4 (patients). Box plot shows relative (GlyR:AMPAR) charge transfer. (C) Example traces, example scaled average miniature events and box plot of relative charge transfer for neurons previously incubated in Fab fragments from Control Subject 2 or Patient 4 for 15 min. (D) Example traces, example scaled average miniature events and box plot of relative charge transfer for neurons incubated in Fab fragments generated from Control Subject 2 or Patient 3 for 16 h. (B–D) Vertical scale bar = 50 pA, horizontal scale bar = 1 s for example traces and 10 ms for example scaled miniature events. Horizontal bar = mean, whiskers = SEM, numbers in parentheses = number of cells. Horizontal bars indicate statistical significance P < 0.05 by two-tailed Mann-Whitney U-tests.