Fig. 5.

Exogenous dopamine induced the positive turning of a target cell growth cone. The outgrowth of a target cell growth cone was monitored for 60 min (A, 60 min). Exogenous dopamine (10⁻⁵m) was pressure applied at an angle to the target growth cone (starting at 60 min and applied in a pulsatile manner for 3 min, repeated 3 times with 10 min intervals).B, At 90 min, the growth cone started to turn toward the dopamine source. C, The target growth cone turned and grew in the direction of the exogenous source of dopamine (135 min). Scale bar, 50 μm.