Physical coupling between the posterior and anterior neural plate is necessary for anterior neural plate directed movement. Time lapse recording of a posterior neural plate explant (left) and an anterior neural plate explant. Note that during deformation of the posterior neural plate explant due to convergent extension, the anterior neural plate explants does not display directed forward movement towards the anterior (top). Magenta: mem-GFP, Grey: Histone-RFP. Time interval: 3 min.