Fig. 1

Seizure phenotype in larval stxbp1b mutant zebrafish. A, Local field potential (LFP) recording from a representative agarose-embedded stxbp1b mutant at 4 d postfertilization (dpf). Electrode is located in the optic tectum. At top is a schematic of the experimental protocol for baseline (0–15 min) and test drug exposure (15–60 min) periods. Test drug in this example is phenytoin (PHT). Type II ictal-like events are denoted by open circles (red). A 60-min continuous gap-free LFP recording trace (top) and associated spectrogram (at bottom) are shown. B, Representative images from age-matched wild-type (WT) sibling and darkly pigmented stxbp1b mutant larvae at 4 dpf. C, Example of a Type II ictal-like event identified using an amplitude threshold detector set to exclude small-amplitude brief interictal-like activity. Note the presence of a brief period of postictal depression in the electrical recording following the event. D, Plot showing the frequency of Type II ictal-like events in stxbp1b mutant larvae used for pharmacology studies (n = 84)