Fig. 4

Schwann cell migration on fibers reduced sex-based differences. (A) Cells paths indicate the influence of aligned fibers, with migration primarily along the x-axis of fiber alignment. Columns are separated by fiber diameter, with male (i, iii and v) in black and female (ii, iv and vi) in pink. (B) MSD was calculated and the MSD curve for 1.8 µm fibers was lower for females compared to other fibers and controls, but males showed no differences. Each graph has the MSD for the appropriate fiber group and its flat control. (C) The fit of α for anomalous migration was found to increase over controls but showed no differences between the sexes. The increase in α for fibers indicated further increased persistence. Within each sex, α parameters statistically increased on fibers compared to flat substrates. (D) The velocity vector indicated that the movement was primarily in the x-direction, as expected, with cells moving back and forth along the fiber, averaging to a 0 overall velocity. (E) The PR was again calculated for the fibers and while it increased from controls, minimal differences were found between the sexes except on 1.8 µm fibers, where male cells were more persistent than female cells. (F) The differences in speed (along fiber axis or x axis for controls) between sex was reduced with the addition of fibers at 0.9 µm, but the female cells showed increased speed with the larger fibers over male cells. Three biological replicates (N = 3) were completed per sex, where at least 100 individual cells were included (0.9 µm - n_male = 124, n_female = 124; 1.2 µm - n_male = 138, n_female = 134); 1.8 µm - n_male = 169, n_female = 139). Statistical analyses were calculated using two-tailed unpaired t-test (control) and two-way ANOVA test with Tukey as a post hoc test (fiber). Error bar: standard deviation.