Fig. 3. Disrupted neuronal migration in 3 integrin deficient cortex. Neurons in wild-type and mutant E15-E16 cortices were labeled with BAPTA green. Labeled cells in the intermediate zone of the slices, migrating in radial direction (A,B), towards the ventricular zone (C,D) or in tangential orientation (E,F) were repeatedly monitored. (A,C,E,G) In wild-type cortex, neurons migrated radially, tangentially and towards the ventricular zone at an average rate of 27±3.2 µm/hour, 43.5±5.4 µm/hour and 43±3.9 µm/hour, respectively. Arrowheads in A,C,E indicate sample migrating wild-type cells. (B,F,G) In 3ß1 integrin-deficient cortex, the rates of radial and tangential migration of neurons were significantly reduced to 16±1.6 µm/hour, 29±3.1 µm/hour, respectively. By contrast, no significant differences were noticed in the rate of ventricular zone directed neuronal migration (C,D; wild type, 43±3.9 µm/hour; mutant, 37±4.1 µm/hour). Arrows in B,D,F indicate sample migrating 3 integrin mutant cells. n=80 for radial wild type and mutant; n=80 for tangential wild type, n=75 for mutant; n=50 for wild type, ventricular zone directed, n=20 for mutant. Data shown are mean±s.e.m.; asterisk (G), significant when compared with controls at P<0.01 (Student's t-test). Time elapsed since the beginning of observations are indicated in minutes. P and V, direction of the pial and ventricular surfaces, respectively. Scale bar: 50 µm in A-D; 40 µm in E,F. (Also see the Figs S2, S3 and Movies 1, 2 in the supplementary material.)