Organization of tripartite DLM neuromuscular synapses.

<p>(<b>A</b>) A lateral view of the dissected thorax showing a stack of six DLM fibers (numbered). Each fiber is innervated by a motor axon projecting from the thoracic ganglion (TG) through the Posterior Dorsal Mesothoracic Nerve (PDMN). (<b>B</b>) Confocal immunofluorescence image showing the distribution of PDMN branches (blue) and associated glia (red) over the surface of a DLM stack. Anti-HRP labels the neuronal plasma membrane and anti-GS2 labels glia. (<b>C-H</b>) Confocal immunofluorescence images of DLM neuromuscular synapses. Triple labeling with anti-HRP, anti-GS2 and anti-SYNAPTOTAGMIN (SYT, a synaptic vesicle marker). Fine terminal axon branches make synaptic contacts on the muscle (<b>C,F</b>) in association with glial processes (<b>D,G</b>) to form tripartite neuromuscular synapses (<b>E,H</b>).