Neurogenesis in Monkey and Human Adult Brain

Abstract

This paper summarizes the results of our studies on adult neurogenesis in some key structures of the monkey and human brain. These results stem from multiple immunocytochemical investigations undertaken with antigens raised against various molecular markers of neurogenesis, either alone or in combination with the DNA synthesis indicator bromodeoxyuridine (BrdU). This approach has allowed us to provide the first detailed picture of the organization of the rostral migratory stream (RMS) in adult squirrel monkeys. Furthermore, studies on human postmortem tissue have revealed, for the first time, that the adult human olfactory bulb is the recipient of neuroblasts that migrate along the RMS and progressively develop a GABAergic or dopaminergic phenotype. A new migratory stream that provides newborn neurons to the amygdala and adjacent piriform cortex has also been visualized in squirrel monkeys. Finally, the striatum of normal adult squirrel monkeys was found to harbor newly generated cells that eventually become projection neurons. The recruitment of such striatal neurons was markedly increased in the presence of brain-derived neurotrophic factor (BDNF), a finding that raises hope for the development of novel therapeutic approaches for the treatment of certain neurodegenerative diseases.