Guidance cues for neuronal migration regulate activities of CCs. (a, left) Local perfusion with the attractive cue BDNF (50 ng/ml) guided neuron migration. Broken lines, perfusion pipette for BDNF delivery sequentially at the end of the LP and TP. Note the direction of soma translocation after BDNF perfusion at each location. (a, right) Summary of the BDNF effect on the velocity of soma translocation. BDNF was applied at the distal region of the long process, and the soma velocity (+ and −, toward and away from the long process) was monitored for 9–40 min before and after BDNF application. Note the increase in velocity toward the tip of the LP (P = 0.014, paired t test). (b) Line scan (along the red trace shown on the left) of the stress produced by a neuron before and after bath application of BDNF (50 ng/ml), showing overall increase in the stress. Red dots, location of dominant CC. (c) Changes in the total strain energy of the neuron after bath treatment with various agents: BDNF (50 ng/ml) + ML141 (15 µM), Slit2 (0.5 µg/ml), Y27632 (25 µM), ML141 (15 µM). Results from all cells examined for five different treatments are shown. (d and e, left) Line scan (red trace on the schematic cell) of the stress produced by two neurons before and after local application of BDNF and Slit2 in front of the long process. Green dots, location of the dominant CC; cyan line, soma center. (d and e, right) Locations of dominant CCs relative to the soma center before and after local perfusion of BDNF and Slit2 for 10–40 min were summarized. Note the forward and rearward movement of the dominant CCs induced by BDNF and Slit2 perfusion at the long process.