Figure 9.

Data summarizing the measurement of a neural growth cone with ERISM. (a) Phase-contrast images and corresponding displacement maps for four different time points are shown. Scale bar, 20 μm. The white arrows are reference points between phase-contrast images and displacement maps. (b) The profile of the vertical displacement at the position indicated by the white dotted line in (a) is given. The ERISM signal is 12 nm, calculated by subtracting the value at maximal pushing from the value at maximal pulling. The lateral force has been calculated as explained in the text. (c) The ERISM signal (black) and noise (at a position where no forces are exerted by growth cone, magenta) are shown for the 3.2 h of the experiment. (d) A close-up of ERISM signal and noise level over 10 min. Black squares indicate the actual data points, and the blue line is a guide to the eye and corresponds to the line in (c). (e) The lateral force (red dotted line) and growth cone speed over time (black line, smoothed with 5-min gliding average) are given. The arrows indicate prominent anticorrelations between lateral force and growth cone speed. To see this figure in color, go online.