Fig. 7. BrdU pulse-chase and histological analysis of late neuron development in DKO spinal cord. (A,B) Late-born interneurons were pulsed with BrdU at E12.5, and were analyzed at E14.5 when the downregulation of Gad1 is first observed in the dorsal horn. The distribution of BrdU⁺ cells in wild-type (wt) and DKO spinal cord is similar, suggesting that there are no major defects in cell birth or cell migration in the DKO cord. (C-F) Anatomical analysis indicates no marked loss of neurons in the superficial dorsal horn. The dorsal funiculus is reduced in size (arrowheads) in the lumbar spinal enlargement of the DKO cord. E and F: enlargements of the boxed regions in C and D.