Figure 2. Neuromuscular analysis of Cntn1 mutant mice.

A) Neuromuscular junctions in wild type P11 mice have a plaque-like field of postsynaptic acetylcholine receptors (red) that is beginning to become convoluted. This is completely overlapped by the presynaptic motor nerve terminal (green). B) A similar NMJ morphology is seen in Cntn1 mutant mice. Histological examination of longitudinal and cross sections of control (C,D), and mutant (E,F) hind limb muscles at P13 did not reveal hallmarks of myopathy. G,H) Transmission electron microscopy was used to evaluate sarcomere anatomy in the tibialis anterior muscle. The structure was not adversely affected by the mutation. I) The absolute maximal contractile force of the extensor digitorum longus muscle was reduced in mutant mice. J) When normalized for muscle weight, contractile force of mutant muscle was not significantly different than control. The scale bar in H represents 14 µm in A, B, 72 µm in C–F, and 3 µm in G, H.