Figure 5.

Effects of SV and DCV secretion on 5-HT accumulation in 5-HT-absorbing neurons. a–f, Photomicrographs of 5-HT immunostaining of mutants affecting SV secretion (snt-1 and snb-1), DCV secretion (unc-31), and both forms of secretion (unc-13, unc-18, unc-64, and unc-104). All the animals shown were adults with anterior to the left. Arrows point to bulged 5-HT immunoreactivity at the end of NSM axons, which could reflect the accumulation of unreleased 5-HT vesicles in the mutant neurons. g, Quantification of 5-HT immunoreactivity in AIM. Data represent the average of 15 animals per strain ± SEM, and the value of the mutants is normalized to that of WT stained in parallel. The experiments have been performed multiple times, and the results from the other trials were similar. ***p < 0.001, Student's t test.