Fig. 12

Individual branches change their orientation of growth in response to altered netrin levels. a, b The maximum projections of each confocal z-stack of two sample neurons at the 0-, 2-, and 4-h imaging time points, and the corresponding 90° view of each three-dimensional z-stack, illustrate the dynamic changes in growth and directionality of individual dendrites in response to acute netrin-1 treatment. The neuron in a corresponds to that shown in Fig. 5b. b’ For the sample neuron in b, a single primary dendrite and its individual secondary branches of the same branch can be discerned in the higher magnification images by selecting and projecting only the z-planes from each confocal stack that include that branch. By isolating the individual dendrite from the rest of the dendritic arbor, one can better differentiate the change in the direction of growth of the primary dendrite (short white arrows) that took place while some of its secondary branches were pruned (double blue arrows) or changed their direction of growth (green arrow) and others were maintained. Scale bars: 20 μm