all the neurons of the ion are generated ( i.e. , pass through their last phase of dna synthesis ) over a 50-hour period between the latter part of the fifth and the seventh days of incubation ( stages 28 -- 31 of the hamburger and hamilton [ '51 ] series ) but the cells come to be assembled within the nucleus along a distinct temporo-spatial gradient .
C0007634
cells
C0007610
nucleus