FORMACIÓN DE NEURONAS NUEVAS EN EL HIPOCAMPO ADULTO: NEUROGÉNESIS
Gerardo Ramírez-Rodriguez1,2, Gloria Benítez-King1, Gerd Kempermann2

SUMMARY
New neuron formation in the adult brain was an interesting finding that extended the knowledge about brain plasticity. In 1966 Joseph Altman reported the incorporation of tritiated thymidine to neural cell DNA. This finding indicated the proliferation event in the adult brain. After twenty years of this finding, new information was generated that confirmed the new neuron formation in the adulthood. In this review, we will mention different aspects of the new neuron formation process called neurogenesis, as well as some of the factors that modulate such process, citing the information already …ver más…

The niche also plays a key role in maintaining the astrocytic and the endothelial cell populations. Besides the niche, other factors are involved in the neurogenic process, such as the neurotransmitters (GABA, glutamate, serotonin, dopamine), hormones (prolactin, growth hormone), growth factors (FGF, EGF) and neurotrophins (BDNF, NT3). All of them modulate different steps of the process. Some other factors that influence the new neuron formation include the physical activity, enrichment environment and social interaction. It has been shown that physical activity increases the number of surviving newborn cells when rodents have free access to the running wheel. Another positive regulator of the neurogenic process is the enrichment environment. The influence of this factor on the new neuron formation was demonstrated when the animals were maintained in a cage with tunnels and toys. In addition, when the rodents were forced to learn a particular task, more new neurons were found in the dentate gyrus. Additionally, the social interaction has a positive influence on the new neuron formation. Even when neurogenesis is positively regulated by the afore mentioned factors, different conditions and factors have a negati-

Instituto Nacional de Psiquiatría Ramón de la Fuente. Departamento de Neurofarmacología, Subdirección de Investigaciones Clínicas, México D.F. Max Delbrück Center for Molecular Medicine (MDC), Berlin-Buch, Alemania. Correspondencia: Dr.