Temporal evolution of the azimuthally averaged density (top row) and metallicity (middle row) disc profiles for our galaxy models. Bulge particles are not considered. The different times shown are color coded as indicated in the second row, third column. The time evolution of the bars’ corotation and outer Lindblad resonances are shown by the dotted and solid vertical lines, respectively, where the colors correspond to the different times. Note that the bars slow down considerably, especially in the simulation lacking a gaseous component (gS0).