The subventricular zone (SVZ) is an embryonic remnant that persists and remains 
mitotically active throughout adulthood. The rodent SVZ harbors neuronal 
precursors, principally in its anterior part, and generates neuroblasts that 
migrate tangentially into the olfactory bulb, thus forming the so-called rostral 
migratory stream. This study aimed at characterizing the SVZ in the human brain. 
Antibodies raised against the widely used SVZ molecular markers nestin, glial 
fibrillary acidic protein, beta-tubulin-III and polysialylated neural cell 
adhesion molecule, have allowed us to characterize in detail a zone similar to 
the rodent SVZ in humans. Virtually all portions of the lateral ventricle, as 
well as the ventral (hypothalamic) sector of the third ventricle, displayed 
immunoreactivity for most of the molecular markers. The midline region of the 
septum (septal recess) and the ventral portion of the SVZ displayed a 
particularly intense immunostaining for all SVZ markers. These two regions may 
represent zones of adult neurogenesis that are unique to primates. Furthermore, 
the anti-apoptotic protein Bcl-2 was found to be actively synthesized and 
co-expressed with all the other markers throughout the entire SVZ. This study 
reveals that a well-developed SVZ exists in the adult human brain and suggests 
that Bcl-2 might play an important role in the functional organization of such a 
system.