Fig. 7. Pharmacological block of neural activity phenocopies the effect of the mao mutation on Rohon-Beard peripheral processes. (A) Wild-type embryos were treated with 0.006% tricaine between 24-72 hpf. Untreated (top) and tricaine-treated (bottom) embryos develop normally without obvious gross morphological differences. Scale bar: 200 µm. (B) aat immunoreactivity in a 60 hpf wild-type (top) is present in varicosities, as found in mao sibling embryos of similar age (Fig. 3B; data not shown). By contrast, tricaine-treated embryos (bottom) do not develop aat-positive varicosities. Thus, tricaine-treatment phenocopies the effect of the mao mutation on RB peripheral processes (Fig. 3D). Scale bar: 20 µm.