Adult-Born Hippocampal Neurons Are More Numerous, Faster Maturing, and More Involved in Behavior in Rats than in Mice

Unit on Neuroplasticity, National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland 20892, USA.
The Journal of Neuroscience : The Official Journal of the Society for Neuroscience (Impact Factor: 6.34). 11/2009; 29(46):14484-95. DOI: 10.1523/JNEUROSCI.1768-09.2009
Source: PubMed


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.

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Available from: Jason Snyder, Jul 22, 2014
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    • "En résumé, le blocage de la neurogenèse adulte hippocampique, que ce soit par méthode chimique, physique ou génétique, induit un certain nombre de déficits de mémoires dépendantes de l'hippocampe . Les quelques résultats contradictoires observés peuventêtrepeuventêtre en partie expliqués par les types de mémoiresmémoiresétudiées, l'hétérogénéité des protocoles utilisés , les différentes espèces, mais aussi les différentes méthodesdeBruel-Jungerman et al., 2006 ;Snyder et al., 2009)Snyder et al., 2009). De même, la réexposition réexpositionà un environnement enrichi familier ainsi que le rap- peì a long terme d'une mémoire spatiale ou encore le réapprentissage 4 semaines après lapremì ere exposition recrutent des nouveaux neuronesâgésneuronesˆneuronesâgés de 1 ` a 2 semaines (Tashiro et al., 2007 ;Trouche et al., 2009 ;Epp et al., 2011b). "
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