Movie 1.

Cyclopamine-mediated inhibition of Smo induced aberrant dI1 axon guidance at the contralateral floorplate border. Twenty-four hours of time-lapse recordings of the ventral midline of ex vivo spinal cords show Math1::tdTomato-F-positive dI1 axons (black) at the contralateral floorplate border in an ethanol-treated control (EtOH) or Cyclopamine-treated sample (Cyclop). dI1 axons turned rostrally in an organized manner in the control, but many of them showed aberrant trajectories in the presence of Cyclopamine. Maximum projections of z-stacks taken every 15 minutes. Rostral is up.