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Neurogenesis in the adult is involved in the formation of trace memories

A Corrigendum to this article was published on 20 December 2001


The vertebrate brain continues to produce new neurons throughout life1,2,3,4,5,6,7,8,9,10,11,12. In the rat hippocampus, several thousand are produced each day, many of which die within weeks13. Associative learning can enhance their survival13,14; however, until now it was unknown whether new neurons are involved in memory formation. Here we show that a substantial reduction in the number of newly generated neurons in the adult rat impairs hippocampal-dependent trace conditioning, a task in which an animal must associate stimuli that are separated in time15. A similar reduction did not affect learning when the same stimuli are not separated in time, a task that is hippocampal-independent16,17. The reduction in neurogenesis did not induce death of mature hippocampal neurons or permanently alter neurophysiological properties of the CA1 region, such as long-term potentiation. Moreover, recovery of cell production was associated with the ability to acquire trace memories. These results indicate that newly generated neurons in the adult are not only affected by the formation of a hippocampal-dependent memory13, but also participate in it.

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Figure 1: Adult-generated neurons are involved in trace but not in delay conditioning.
Figure 2: MAM treatment decreases number of BrdU-labelled cells in dentate gyrus and does not alter gross morphology.
Figure 3: Reduction of adult-generated granule cells in the hippocampus does not affect neurophysiological responses in area CA1.
Figure 4: Trace conditioning is not affected when newly generated cells are less than one week of age or proliferation recovers.


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We thank L. D. Matzel for comments and L. King, G. Kozorovitskiy and B. DiCicco-Bloom for technical assistance. This work is supported by NIMH, NSF, the National Alliance for Research on Schizophrenia and Depression, and the van Ameringen Foundation to T.J.S., and NIMH to E.G.

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Correspondence to Tracey J. Shors.

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Shors, T., Miesegaes, G., Beylin, A. et al. Neurogenesis in the adult is involved in the formation of trace memories. Nature 410, 372–376 (2001).

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