Figure 2.

Measuring cascades in zebrafish optic tectum

(A) Calcium imaging in neurod1:GCaMP6f-expressed larval zebrafish. Neuronal dynamics within optic tectum (highlighted by white dash line) were extracted for cascade measurement.

(B) Calcium traces (ΔF/F) from pixels within the optic tectum in a stxbp1b mutant fish on 6 days post fertilization (dpf). A pixel is considered to be active when ΔF/F crosses the threshold of 5 times signal standard deviation (+5 SD). One pixel is 2.67 × 2.67 μm area. Simultaneously recorded local field potential (LFP) recording from midbrain is shown below. Scale bars as indicated in figure.

(C and D) Binarized activity from episodes indicated in (B) (underlined in red). One normal cascade was revealed in (C), and multiple cascades were revealed in (D), including an abnormally large and long cascade located in the left optic tectum. The last frame represents the summation of the binary time series stack of the corresponding episode showing the spatial mapping of the cascades. The cumulative intensity of activation is color coded as shown in the color bar. Scale bars, 100 μm.