TRIM67 regulates filopodial growth and dynamics. (A) Kymographs of filopodia from cultured primary embryonic cortical neurons expressing mCherry. (B) Individual data points and box plots of filopodial lifetime. n (filopodia) = 293 +/+ media, 278 +/+ netrin, 257 −/− media, 226 −/− netrin. (C) Fluorescent micrographs and quantification of filopodial buckling and folding events during the course of 10-min time-lapse of axonal growth cones. (D and E) Individual data points and box-and-whisker plots of rate of filopodial tip protrusions and retractions (D) and duration of individual filopodial protrusion and retraction periods (E) following media sham or netrin treatment. n (events) = protrusion: 142 +/+ media, 193 +/+ netrin, 171 −/− media, 136 −/− netrin; retraction: 151 +/+ media, 226 +/+ netrin, 174 −/− media, 151 −/− netrin. Three experiments per genotype/treatment for all panels. *, P < 0.05; **, P < 0.01; ***, P < 0.005; n.s., P > 0.05. Box plots are minimum, Q1, Q2, Q3, maximum.