Fig. 6. Lhx1 and Lhx5 regulate late aspects of development in Pax2 inhibitory interneurons. (A-D) Dorsal horn quadrants showing the downregulation of Pax2 in dIL_A neurons. This downregulation begins at E12.5 in DKO animals (asterisk, B) and is more pronounced at E14.5 (asterisk, D). (E-H)Lmx1b⁺ dIL_B neurons are specified normally and settle in the superficial dorsal horn in DKO animals at similar stages to wild type. (I-L) VGluT2 is not upregulated in the superficial dorsal horn (arrows) indicating that GABAergic Pax2⁺ cells do not adopt a dIL_B glutamatergic phenotype in the DKO cord. (M,N) E17.5 DKO animals exhibit a loss of Pax2 expression both dorsally and ventrally at E17.5. (O) Cell counts of Pax2⁺ and Lmx1b⁺ cells at E14.5 show a >60% reduction in the number of dorsal Pax2⁺ cells without any increase in the number of Lmx1b⁺ dIL_B cells.