Fraction of all dentate gyrus granule cells that are new (defined as <8 weeks of age) neurons

Range at 3 months old >25%: at 12 months old 5% % of all dentate gyrus granule cells
Organism Rat Rattus norvegicus
Reference Josselyn SA, Frankland PW. Infantile amnesia: a neurogenic hypothesis. Learn Mem. 2012 Aug 16 19(9):423-33. doi: 10.1101/lm.021311.110 p.428 right column 2nd paragraphPubMed ID22904373
Primary Source Snyder JS, Cameron HA. 2011. Could adult hippocampal neurogenesis be relevant for human behavior? Behav Brain Res 227: 384–390 link PubMed ID21736900
Method Primary source abstract: "In this review [investigators] examine neuroanatomy and circuit function in the hippocampus to ask how many granule neurons are needed to impact hippocampal function and then discuss what is known about numbers of new neurons produced in adult rats and humans."
Comments P.428 right column 2nd paragraph: "In young adult rodents, several thousand new neurons are generated daily (Cameron and McKay 2001). While not all of these new neurons survive, they still represent a sizable proportion of all dentate granule cells. For example, in the 3-mo-old rat, new neurons (defined as <8 wk of age) are estimated to make up >25% of the entire granule cell population. This percentage drops with age, but even so, at 12 mo, new neurons likely account for 5% of all dentate granule cells (primary source)."
Entered by Uri M
ID 117231