Continuity and discontinuity of the radial scaffolding in the forebrain of a lizard embryo.

We have used ventricular injections of the fluorescent carbocyanine dye DiI (Molecular Probes, Eugene, OR, USA) to demonstrate the scaffolding of the radial ventricular cells in the embryonic forebrain of lizards. The results reveal changes of density, orientation, or thickness of the radial processes between adjacent regions. On the whole, they support the idea that the hypothalamus together with the telencephalic stalk and the telencephalic hemispheres make up the anterior region of the neural tube or secondary prosencephalon, as proposed by the prosomeric model.