Figure 5.

Synaptic protrusions develop after initial synaptogenesis is complete and their location is age and activity dependent. A, An early L3 gon-1(q518) larva exhibiting no synaptic protrusions. B, A mid-L4 gon-1(q518) larva. Synaptic protrusions are largely restricted to the posterior third of the worm (Box 1). Boxes indicate areas of magnification below. C, A young adult gon-1(q518) exhibiting more pronounced synaptic protrusions. D, A 2-d-old adult gon-1(q518) with synaptic protrusions visible along the length of the worm (arrows), although still most pronounced in the most posterior region (asterisks). E, F, Crossing gon-1(q518) into the synaptic activity mutants unc-32(e189) (E) and unc-3(e151) (F) leads to an enhancement of the phenotype such that protrusions are no longer limited to the posterior region. Boxes indicate areas of magnification below. Scale bars: A, 20 μm; B, 50 μm, insets, 20 μm; C, 20 μm; D, 50 μm; E, F, 50 μm, insets, 20 μm.