Neurons adult-generated

The proposed neurogenesis-memory clearance hypothesis is attractive because addition and removal of adult-born neurons in local network architecture could gradually destabilize the stored memory traces. Also, adult-generated neurons within the dentate gyrus, the upstream location in the hippocampus, potentially can amplify the destabilization effects. Coincidently, these newborn neurons are short-lived, typically with a life-span of three weeks in rodents [40], which seems to correlate well with the duration of hippocampal dependence of declarative memories. 

Markakis, E.A., Gage, F.H. (1999). Adult-generated neurons in the dentate gyrus send axonal projections to field CA3 and are surrounded by synaptic vesicles. J Comp Neurol, 406, 449-60. 

Gould, E., Vail, N., Wagers, M., Gross, C.G. (2001) Adult-generated hippocampal and neocortical neurons in macaques have a transient existence. Proc Natl Acad Sci USA 98, 10910-7. 

Kempermann, G., Gast, D., Kronenberg, G., Yamaguchi, M., Gage, F.H. (2003) Early determination and long-term persistence of adult-generated new neurons in the hippocampus of mice. Development 130, 391-9. 

Fig. 64 Distribution and phenotype of adult-generated cells in postischemic monkey DG at short-term andlong-term survival time periods al ter surgery. Note the numerous progenitor cells forming clusters in SGZ at short-term survival some of these cells were preserved at long-term survival. Typical for the early periods after ischemia were neuronal progenitors extending processes parallel to DGL, while atlong-term survival the processes were spanning DGL. The quantity of newly generated cells with a mature neuronal phenotype increased over time...

For many years, it was thought that the adult nervous system was unable to generate new neurons after all, neural trauma or disease is devastating and essentially... 

FIGURE 29-5 In the adult rodent brain, dividing cells in the subventricular zone adjacent to the lateral ventricle migrate in the rostral migratory stream (RMS) and differentiate into olfactory neurons in the olfactory bulb (OB). This is one site of neuronal turnover in the adult that appears to result from persistent generation of neurons from adult CNS stem cells. CIS, cerebellum NC, neocortex. 

Reynolds, B. A. and Weiss, S. Generation of neurons and astrocytes from isolated cells from the adult mammalian central nervous system. Science 255 1707-1710,1992. 

Wu, P., Tarasenko,Y. I., Gu,Y., Huang, L. Y., Coggeshall, R. E. and Yu, Y. Region-specific generation of cholinergic neurons from fetal human neural stem cells grafted in adult rat. Nat. Neurosci. 5 1271-1278,2002. 

Gheusi, G., Cremer, H., McLean, H., Chazal, G., Vincent, J.D. and Lledo, P.M. (2000) Importance of newly rly generated neurons in the adult olfactory bulb for odor discrimination. Proc Natl Acad Sci USA. 97, 1823-8. 

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