Figure 1.

Models for studying muscle postsynaptic machinery. (a) Complex structure of postsynaptic machinery at the murine NMJ (b) Differentiated C2C12 myotubes that were stimulated with a neuron-specific splice variant of the glycoprotein agrin that was supplemented to the media formed small, elongated AChR clusters on the lateral and apical sides of the myotubes. (c) C2C12 myotubes that were grown on a laminin substratum with deposited agrin patches formed large uniform AChR assemblies at the basal surface of the myotubes. (d) C2C12 myotubes that were grown on mouse laminin-111-coated surfaces formed clusters of postsynaptic machinery that underwent developmental remodeling to topologically complex assemblies that resembled the shape of postsynaptic machinery at the NMJ. Scale bar = 6 μm. AChRs were visualized with α-bungarotoxin.