Axon shows robustness and nonlocalization in contraction. (A) Experimental images showing an axon contract during three consecutive slackening cycles. The contraction strain in each cycle is 10–15% of the initial length ( in each cycle). Note that the axon contracts and becomes taut upon each push within 2–4 min. The total shortening is ∼40% of the original length ( in cycle 1). (B) for each compression cycle, demonstrating robust axonal contractility (n = 6 in all groups). (C) Time constants of contraction for axons pushed (first time) immediately after surgical preparation, pushed (first time) 1 h after surgery, and pushed the second time 1 h after the first push (n = 6 in all groups). (D) The same axon overlaid at different time points—0, 10, 20, 30, and 50 s—after a push. Movements of fluorescence intensity features (red arrows) reveal a change in forcing direction along the length. All error bars indicate the standard deviation. To see this figure in color, go online.