Adult-born hippocampal neurons are more numerous, faster-maturing and more involved in behavior in rats than in mice

By J. Snyder, Jessica S. Choe, Meredith A. Clifford, Sara I. Jeurling, Patrick Hurley, Ashly Brown, J. Kamhi, Heather A. Cameron. 2009

454 citations recorded by the source corpus.

Neurons are born throughout adulthood in the hippocampus and show enhanced plasticity compared with mature neurons. However, there are conflicting reports on whether or not young neurons contribute to performance in behavioral tasks, and there is no clear relationship between the timing of maturation of young neurons and the duration of neurogenesis reduction in studies showing behavioral deficits. We asked whether these discrepancies could reflect differences in the properties of young neurons in mice and rats. We report that young neurons in adult rats show a mature neuronal marker profile and activity-induced immediate early gene expression 1–2 weeks earlier than those in mice. They are also twice as likely to escape cell death, and are 10 times more likely to be recruited into learning circuits. This comparison holds true in two different strains of mice, both of which show high rates of neurogenesis relative to other background strains. Differences in adult neurogenesis are not limited to the hippocampus, as the density of new neocortical neurons was 5 times greater in rats than in mice. Finally, in a test of function, we find that the contribution of young neurons to fear memory is much greater in rats than in mice. These results reveal substantial differences in new neuron plasticity and function between these two commonly studied rodent species.

Subfields: Cellular and Molecular Neuroscience, Developmental Neuroscience

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Cellular and Molecular Neuroscience

In Developmental Neuroscience

Citations in the corpus

New neurons and new memories: how does adult hippocampal neurogenesis affect learning and memory? (2010, background): “The kinetics of DGC maturation are species dependen”
Maturation time of new granule cells in the dentate gyrus of adult macaque monkeys exceeds six months (2011, background): “In rats, there are an estimated 3,000 BrdU+ cells/hippocampus (15), which is ∼25 new cells/10,000 granule A 48 Hours B 2 Weeks C 6 Weeks D 23 Weeks”
Adult neurogenesis and the plasticity of the dentate gyrus network (2011, background): “While the timing described above has been consistently observed in mice studies, maturation seems to occur at a faster pace in the rat hippocampus (Snyder et al., 2009).”
Human adult neurogenesis: evidence and remaining questions (2018, background): “A report by Sorrells et al. (2018) concluded that neurogenesis in the human hippocampal dentate gyrus drops to undetectable amounts during childhood, and that the human hippocampus must function differently from that in other species, in which adult neurogenesis is conserved (Sorrells et al., 2018).”
Young dentate granule cells mediate pattern separation, whereas old granule cells facilitate pattern completion. (2012, unknown): “This conclusion was supported by the lack of GFP expression in the adult-born doublecortin (DCX)-positive GCs (a marker for up to 3-week-old cells) (Nacher et al., 2001; Snyder et al., 2009) in the DG-GFP mice (Figures 3G–3K).”