Figure 1.

Ventricular zones with variable proliferative activity can be detected throughout the axolotl central nervous system. (A) Structure of the axolotl brain showing the levels at which sections ventricular zone proliferation was analyzed. B = anterior telencephalon and olfactory nerve, C = anterior telencephalon and olfactory bulb, D = posterior telencephalon, E = mesencephalon, F = cerebellum, G = rhombencephalon; on: olfactory nerve. Scale bar = 1 mm. (B – G) Cumulative BrdU⁺ cell numbers on five sections from each level depicted in A on which individual labeled cells are marked with a red dot. Regions of the brain are marked.; on: olfactory nerve; ob: olfactory bulb; cp: choroid plexus.