Fig. 4.

Factors affecting neutrophil spreading. The effect of uncaging Ca²⁺ (nitr5) to a level of the initial (release) phase of the caged IP₃-induced Ca²⁺ signal. (A) The matching of initial (release) phase of the caged IP₃-induced Ca²⁺ signal (upper graph ‘cIP₃’) and nitr5 uncaging followed by addition of f-mlp (lower graph). (B) Graphs are showing the effect of f-mlp addition from A in more detail, with the accompanying effect on the cell ‘footprint’ and (C) images of the cell and its cytosolic free Ca²⁺ from which the data was taken. (D–F) The effect of the pre-treatment of neutrophils with cytochalasin B (5 µg/ml) before uncaging IP₃: (D) a series of phase contrast and fluo4 images, (E) quantification of cytosolic free Ca²⁺, footprint and cell roundness [taken as (cell perimeter/π.max cell dimension)], and (F) changes in the reconstructed isosurface of the cell and the position of the nucleus, with the arrowheads indicating local sites of cell deformation. An example of the ‘wriggling response’ to IP₃ uncaging in cytochalasin-B-treated neutrophils is shown in supplementary material Movie 2.