Figure 4.

Locust (Schistoceca gregaria) motor neuron terminals on M85 stained with antibodies to synaptic proteins. (A) Typical appearance of motor neuron terminals on M85 labeled with neurobiotin by anterograde staining of N4D4. Terminals are aligned in parallel to fibers and cover the entire muscle. Z-Dimension of image stack 10 μm, scale bar 10 μm. (B) Labeling of M85 with anti-synapsin I (magenta) in addition to the backfilled motor nerve by neurobiotin (green) highlights the presence and distribution of presynaptic sites (white). Z-Dimension of image stack 30 μm, scale bar 20 μm. (C) Immunoreactivity to the synaptic protein bruchpilot (BRP), BRP^NC82 (green), can be located in motor terminals (magenta, NB-labeled) as distinct puncta presumably representing active zones. Z-Dimension of image stack 30 μm, scale bar 5 μm. (D) Double-labeling with anti-synapsin I (green) and anti-tyramine (magenta) shows the characteristic beaded octopaminergic/tyraminergic fibers in proximity to motor terminals (green, Di). In addition to the markedly stained motor terminals by anti-synapsin (green, Di and Dii, one motor terminal marked by white asterisk) weak labeling in OA/TA-ir boutons is also revealed (white arrows in Di and Dii). Z-dimension of image stacks 10 μm, scale bar 5 μm.