Fig. 7. Spread osteoclasts exhibit different spreading patterns. Membrane spreading is illustrated for three osteoclasts. The right image shows the cell appearance at the beginning of time-lapse recording, and the left image illustrates the cell at the maximum spreading. During this process, some osteoclasts showed a `symmetrical' spreading by radial axes around the nuclei (N) (cell 1), whereas other cells only exhibited membrane movement along a few directions (cells 2 and 3). Membrane spreading may take place over 180° opposite directions, as is seen in cell 3.