POSTNATAL MOUSE SUBVENTRICULAR ZONE NEURONAL PRECURSORS CAN MIGRATE AND DIFFERENTIATE WITHIN MULTIPLE LEVELS OF THE DEVELOPING NEURAXIS

The mammalian subventricular zone (SVZ) of the lateral wall of the for ebrain ventricle retains a population of proliferating neuronal precur sors throughout life, Neuronal precursors born in the postnatal and ad ult SVZ migrate to the olfactory bulb where they differentiate into in terneurons, Here we tested the potential of mouse postnatal SVZ precur sors in the environment of the embryonic brain: (i) a ubiquitous genet ic marker, (ii) a neuron-specific transgene, and (iii) a lipophilic-dy e were used to follow the fate of postnatal day 5-10 SVZ cells grafted into embryonic mouse brain ventricles at day 15 of gestation, Graft-d erived cells were found at multiple levels of the neuraxis, including septum, thalamus, hypothalamus, and in large numbers in the midbrain i nferior colliculus. We observed no integration into the cortex, Neuron al differentiation of graft derived cells was demonstrated by double-s taining with neuron-specific beta-tubulin antibodies, expression of th e neuron-specific transgene, and the dendritic arbors revealed by the lipophilic dye, We conclude that postnatal SVZ cells can migrate throu gh and differentiate into neurons within multiple embryonic brain regi ons other than the olfactory bulb.