When a leaflet is touched, this triggers an action potential in sensing cells at the base of the leaflet. cells at the base of the leaflet respond to this action potential, folding the leaflet inward. if you make a gentle touch that only stimulates the end leaflet, the resulting action potential propagates down the axis that supports all of the leaflets, triggering an action potential in the sensing cells at the base of the adjacent leaflet, then the one next to it, and so on down the line, similar to how electrical signals propagate in the human nervous system. you can watch the progress of this pulse of action potential by watching adjacent leaflets fold inward, one after another. if, instead of a touch, a leaf structure is stimulated with a spark that sends a charge through the structure that holds all of the leaflets, how might you expect the leaflets to behave?