FIGURE 6

Increased early born ventral lateral descending (VeLD interneurons and GABAergic motor neurons of fmr1 embryos (A,B) Live lateral images of trunk spinal cord from embryos expressing mnx1:EGFP, a reporter of primary motor neurons and VeLD interneurons. Asterisks indicate presumptive VeLD interneurons, with large soma situated dorsal and rostral to primary motor neurons. (C) Quantification of the average number of EGFP⁺ cells per hemisegment at 24 hpf. Representative images of immunohistochemistry to detect gamma-aminobutyric acid (GABA) and Islet1 on transverse trunk spinal cord sections of mnx1:EGFP embryos at 24 hpf. mnx1 + cells (D,E) expressed a combination of the motor neuron marker Islet1 (D’,E’) and GABA (D”,E”). Quantification of mnx1⁺Isl1^–GABA⁺ presumptive VeLD interneurons [(F); magenta arrows; two-tailed t-test], mnx1⁺Isl1⁺GABA^– motor neurons [(G); cyan arrows; two-tailed t-test], and mnx1⁺Isl1⁺GABA⁺ motor neurons [(H); white arrows; two-tailed t-test]. Quantification reflects the average number of cells per section, averaged by embryo. Scale bars = 10 μm. P-values indicated in graphs, where p < 0.05 is considered significant.