Neurogenesis in the Mammalian Central Nervous System

Abstract

Medical science have believed firmly for over a century that brain cells are incapable of recreating itself just like other cells of the mammalian body. Tat the adult brain is static in number developing as dendrites and synapses grow around a fixed number of neurons after birth. Over the past two decades, research have confirmed that adult neurogenesis, the process of generating new neurons which integrate into existing circuits after fetal and early postnatal development has ceased, actually occurs in the olfactory bulb and hippocampus of mammals and indeed man. In addition there is a high level of adult neurogenesis in the, olfactory epithelium where olfactory receptor cells are constantly replaced. Furthermore, many vertebrates have neural regeneration capacities that involve neurogenesis (such as tail regeneration in salamanders). This scientific paradygm shift in our view of neurogenesis in the CNS is bound to aid the treatment of certain human disorders if advances in scientific research are able to tackle the unanswered questions. This paper reviews the status research so far and reflects on the current direction of adult neurogenesis in the mammalian central nervous system.