Quantifications of number of AChR clusters in C2C12 cells. 4-d-old C2C12 myotubes were pretreated for 24 h with HDAC6 inhibitors HPOB (5 µM) and TubA (5 µM) or with DMSO (CTL; 1 µl). (A) Quantification of the total fluorescence intensity of AChR clusters per field; n = number of fields of 0.15 mm² counted, between 8 and 15. (B) Quantification of the number of clusters per field; n = number of fields of 0.15 mm² counted, between 10 and 17. Each quantification result from three independent experiments. Means ± SEM. ***, P < 0.001; n.s, not significant; Mann-Whitney U test.