Brain tissue is characterized as a nonlinear viscoelastic material. One intriguing property of brain tissue is material softening at finite strains. In this study, we examine the individual motion of neural and glial cells in slices of brain tissue subjected to a controlled equibiaxial deformation. We compare the cellular motions to the kinematics of nuclei movement in astrocyte monolayers exposed to the same strain field, and to the patterns of bead movement for beads entrapped within a silicone gel surrogate. We find (a) not all cell nuclei in tissue move in response to an applied deformation, (b) the relative fraction of displaced nuclei is sensitive to the applied deformation, but not the distance of the cell from the stretched membrane, and (c) the strains computed from tracking the nuclei of moving cells is not significantly different than the strains computed from astrocyte monlayers or silicone gel surrogates. Together, these suggest a cellular mechanism underlying the strain softening behavior measured for brain tissue. Separately, these developed relationships will help determine the relative number of cells experiencing a deformation under an applied macroscopic strain field.