SDS brain is apoptotic.

<p>Histochemistry of transverse rhombencephalon (E11.5; <b>A</b>) and telencephalon (E14.5; <b>B</b>) brain sections indicate hypocellularity and neuronal cell death (green in TUNEL panels) in post-mitotic regions of <i>Sbds</i>^{<i>R126T/R126T</i>} mice with earlier onset in the <i>Sbds</i>^{<i>R126T/–</i>}mice (compare TUNEL panels in <b>A</b> and <b>B</b>). Bromodeoxyuridine labeling (brown in BrdU panels) highlighted reduced proliferation of neural progenitors. V, lateral ventricle; VZ, ventricular zone; IZ, intermediate zone; CP, cortical plate. Scale bars represent 25 μm.