Figure 6. Cross-sectional area of muscle fibers.

(A–C) Frequency distributions of muscle fiber cross-sectional areas for the diaphragm muscle. (D–F) Cross-sectional areas for fibers from the tibialis anterior muscle. Data were pooled from healthy naive mice (A & D; n = 5 mice) or mice that received 15 daily injections of anti-MuSK IgG together with vehicle (B & E; n = 4 mice) or 8 mg/kg/day albuterol (C & F; n = 4 mice).