Drastic change of local stiffness distribution correlating to cell migration in living fibroblasts

Sequential images of the local stiffness distribution of living fibroblasts (NIH3T3) were captured under a culture condition using scanning probe microscopy in a force modulation mode. We found a clear relation between cell mi-ration and local stiffness distribution on the cell: When cells were stationary at one position, the stiffness distribution of their cellular surface was quite stable. On the other hand, once the cells started to move, the stiffness in their nuclear regions drastically decreased. Possible explanations for the correlation between the cell mi-ration and the cell stiffness are proposed. Cell Motil. Cytoskeleton 50: 173-179,2001. (C) 2001 Wiley-Liss, Inc.