Figure 2. Changes to morphology of adult NMJs in response to NRG1-III overexpression by motor neurons.
Unlike the mature NMJs of control mice, those in animals that overexpress NRG1-III show signs of remodeling. The postsynaptic AChR aggregates are no longer found in “pretzel-like” continuous gutters, but in fragmented islands that are innervated by varicose presynaptic terminal branches. Some AChR-islands are abandoned by the motor terminal branches (arrowhead) and appear to be in the process of elimination. In addition, there is a significant increase in the number of tSCs, some of which extend long processes within and beyond the synaptic area. Scale bar: 10 μm.