RIα labeling of the NMJ and adjacent muscle. Individual optical sections from separate z-series were chosen after deblurring that most completely shows the postsynaptic membrane topography in order to demarcate presynaptic from postsynaptic regions. (a) Partial overlap occurs between RIα and synaptophysin, which labels presynaptic vesicles. Overlap is also seen with bungarotoxin, although it is not prominent, scale bar = 10 μm. (b) RIα overlaps the mitochondrial marker in the postsynaptic region, as well as mitochondria in the actin region of muscle fibers. Motor endplates were identified by labeling the nAChR using rhodamine-conjugated α-bungarotoxin. Anti-lipoic acid marks mitochondria only. scale bar = 10 μm.