Constitutive reduction in neuronal DTH results in results in aberrant gut fiber architecture. Analysis of proventricular tissues from 3rd larval instars dissected and incubated with anti-5-HT. A. Neurite branching. B. Number of large varicosities (> 1 μm2) per 0.1 mm neurite length. C. Number of varicosities > 5 μm2 per 0.1 mm length. D. varicosity area. *p < 0.05, ***p < 0.001, one way ANOVA followed by Dunnett's multiple comparisons post-test. w1118/THA;THK, n = 66 fibers from 48 guts from 8 independent experiments; elav/THK, n = 40 fibers from 18 guts from 2 independent experiments; elav/THA, n = 37 fibers from 21 guts from 2 independent experiments; elav/THA;THK, n = 35 fibers from 18 guts from 3 independent experiments. Lines above the graph depict standard error of the mean. E - H. Visual depiction of 5-HT axonal fibers from w1118/THA;THK (E), elav/THK (F), elav/THA (G) and elav/THA;THK (H) guts. Scale bar = 30 μm.