Fig. 8 . Abnormal neuronal maturation in the SVZ-RMS of NCAM^-/- animals is associated with apoptosis and p75 expression. (A) Morphological analysis of cells in SVZ-RMS 4 days after a GFP lentiviral vector injection in the lateral ventricles. In WT animals, GFP⁺ cells display a unipolar morphology typical of migrating cells, whereas in NCAM mutant mice many GFP⁺ cells exhibit a complex branched morphology suggestive of maturating neurons. GFP⁺ cells colocalized with the neuronal marker doublecortin (DCX). (B) NeuN staining in the SVZ-RMS revealed numerous NeuN-positive nuclei in the NCAM mutant mice (arrows). These nuclei were smaller than those found on the cortex (arrowheads). The dashed line indicates the limit between the SVZ-RMS and the overlying corpus callosum and cortex. (C) Colocalization of TUNEL labeling and p75 immunostaining in the NCAM-deficient SVZ-RMS. The upper panel depicts an example of a TUNEL⁺ nucleus that colocalizes with p75, whereas the lower panels illustrate a strongly TUNEL⁺ nucleus that does not colocalize with p75 staining. Note that this latter nucleus is highly condensed, as illustrated by the Hoechst staining. Scale bar: 20 µm in A,B; 10 µm in C.