Authors:
Juan M. Encinas, Tatyana V. Michurina, Natalia Peunova, June-Hee Park, Julie Tordo, Daniel A. Peterson, Gord Fishell, Alex Koulakov, & Grigori Enikolopov
Summary:
Production of new neurons in the adult hippocampus decreases with age; this decline may underlie age-related cognitive impairment. Here we show that continuous depletion of the neural stem cell pool, as a consequence of their division, may contribute to the age-related decrease in hippocampal neurogenesis. Our results indicate that adult hippocampal stem cells, upon exiting their quiescent state, rapidly undergo a series of asymmetric divisions to produce dividing progeny destined to become neurons and subsequently convert into mature astrocytes. Thus, the decrease in the number of neural stem cells is a division-coupled process and is directly related to their production of new neurons. We present a scheme of the neurogenesis cascade in the adult hippocampus that includes a proposed disposable stem cell model and accounts for the disappearance of hippocampal neural stem cells, the appearance of new astrocytes, and the age-related decline in the production of new neurons.
Source:
Cell Stem Cell; Vol. 8, Issue 5, 566-579 (05/06/11)