Fig. 7.

The critical window of OT susceptibility to VPA-treatment includes timepoints prior to 72 hpf. (A) Treatment of y304Et(cfos:Gal4); Tg(UAS:Kaede) embryos from 54 to 120 hpf still resulted in neuropil development defects in the treated embryos (I′-V′) compared to controls (I-V). Therefore, the critical window of susceptibility must extend beyond 54 hpf. (B) A subsequent trial in which VPA treatment was initiated at 78 hpf resulted in a significantly reduced phenotype in treated larvae (IV′-V′). Three embryos per experimental condition were imaged and quantified. (C) Average lobe length at 120 hpf was significantly decreased for both treatment groups. (D) Average lobe width is consistently decreased for the 54-120 hpf treatment group across all days measured. (E) The average lobe depth is significantly decreased for the 54-120 hpf treatment group compared to controls when measured at 96 and 120 hpf. The 78-120 hpf treatment group shows no significant difference with controls. Therefore, the critical window of susceptibility is determined to be time points prior to 72 hpf. At 48 hpf, length, width and depth are difficult to measure since during this time neuroepithelium is transitioning into neuroblasts. A two-way ANOVA with Šidák's multiple comparisons test was performed. *P<0.05, **P<0.01, ***P<0.001, ****P<0.0001. Data are shown as mean±s.e.m.