Lack of GDAP1 leads to loss of motor neurons and abnormal neuromuscular junctions.

<p><b>(A)</b> Anterior horns from lumbar spinal cord of 5 and 12-months-old mice were stained by Nissl staining. Reduced number of MNs and evidence of chromatolysis are visible in <i>Gdap1</i>^<i>-/-</i> mice. <b>(B)</b> Progressive graphics representing the number of healthy motor neurons in anterior horns per section in WT (black line) and <i>Gdap1</i>^<i>-/-</i> (gray line) mice at several ages (n = 3). <b>(C)</b> Representative confocal stack images of NMJs from the gastrocnemius muscle. Axons were immunostained with anti-β-III tubulin (β-III tub, green) and the postsynaptic acetyl-choline receptor was stained with AF488-coupled α-bungarotoxin (BTX, red). <b>(D)</b> Histograms show the percentage of NMJ occupancy by terminal axons in WT (black bars) and <i>Gdap1</i>^<i>-/-</i> (gray bars) mice. <b>(E)</b> Magnification of tangle-like abnormal structures (white arrows) at the terminal axons closed to the NMJ observed in <i>Gdap1</i>^<i>-/-</i> mice muscles. * represents significant differences between WT and <i>Gdap1</i>^<i>-/-</i> mice; <b>&</b> indicates differences between ages of WT mice; and <b>#</b> indicates differences between ages of <i>Gdap1</i>^<i>-/-</i> animals (Student’s <i>t</i> test, data are presented as means ±S.E.M.).