Age dependence of axial, radial, and mean kurtosis (AK, RK, and MK, respectively) in different ROIs of the male guinea pig brain. Graphs illustrate the age dependence of AK, RK, and MK in the corpus callosum (A), striatum (B), thalamus (C), amygdala (D), hippocampus (E), and cerebral cortex (F) in the brain of male guinea pigs. Symbols and error bars represent mean and SD of results obtained from six guinea pigs examined longitudinally at PND 18-25, PND 46-51, and PND 118-123. Whenever ANOVA revealed a significant effect of age on a given parameter, the Tukey post-hoc test was used for multi-group comparisons. Asterisks and daggers are used for comparison, with data obtained at PND 18-25 and PND 46-51, respectively. *, p < 0.05; **, p < 0.01; ***, p < 0.001; †, p < 0.05; ††, p < 0.01.