Figure 2
Surface models of axons of different neurons, tSCs, and vacancies at the NMJs and their contact areas on their endplate. (a,c,e,g) Surface rendering of a series of montaged electron micrographs of the sections of the same NMJs at P0, P3, P7, and P16, respectively. Axons, tSCs, and vacancies are color-coded in the same with Fig. 1. (b,d,f,h) The regions of the axons, tSCs, and vacancies in proximity to their muscle fiber or footprints at their endplate were segmented and using the series of their segmented lines the contact regions of the axons, tSCs, and vacancies were marked in color using the same color-code on their muscle fiber (red). (i) The average relative areas at P0, P3, P7, and P16. From P0 to P3, the relative contact area of tSCs in the endplate increased from 31.0% to 57.0% on average whereas that of axons decreased from 51.6% to 24.8% on average and also that the relative area of vacancies changed little (17.4% at P0 and 18.3% at P3 on average). The relative contact area of tSCs changed little from 57.0% at P3 to 55.6% at P7 and then decreased to 40.7% at P16. The relative contact area of vacancies markedly decreased from 18.3% at P3 to 4.55% at P7 and then changed little (5.82% at P16) whereas the relative contact area of axons significantly increased from 24.8% at P3 to 39.8% at P7 and then to 53.5% at P16.
