Fig. 7

Neuromuscular junctions in the xenografts. Cross sections of unfixed xenografts from group 3 were labeled with Alexa Fluor 633-α-bungarotoxin to visualize postsynaptic acetylcholine receptors (AChRs) (blue; a, b, arrows) and with antibodies to human β-spectrin (red; a, b) and to synaptophysin (green; b, arrowhead) to visualize the sarcolemma of human myofibers and presynaptic structures, respectively. The results show the accumulation of AChRs at the sarcolemma of human myofibers (a, b; arrows) that correspond with sites of innervation (b; arrowhead). Scale bars = 5 μm