Learning-induced survival of new neurons depends on the cognitive status of aged rats
Learning-induced survival of new neurons depends on the cognitive status of aged rats
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DOI：
10.1523/jneurosci.1031-07.2007
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发表时间：
2007-05-30
影响因子：
5.3
通讯作者：
Abrous, Djoher Nora
中科院分区：
文献类型：
--
作者：
Drapeau, Elodie;Montaron, Marie-Francoise;Abrous, Djoher Nora
衰老伴随着空间记忆的改变，这与海马可塑性的改变有关。在齿状回内，新的神经元在个体的整个生命中产生。这种神经发生似乎在海马介导的学习中起作用，并且已经提出学习诱导的神经发生变化与记忆有关。然而，在老年大鼠中，很少有人知道的影响，学习的成年出生的神经元的早期发育和学习诱导的变化可能参与神经发生在年龄相关的记忆缺陷。为了解决这个问题，我们利用了存在的自发性个体差异的表现在老年受试者在水迷宫中观察。在这项任务中，学习可以分为两个阶段，早期阶段，在此期间的性能迅速提高，和后期阶段，在此期间的性能达到渐近水平。我们发现，空间学习对新生细胞存活的影响取决于它们的出生日期和老年大鼠的记忆能力。在保留空间记忆的老年大鼠中，学习增加了学习前产生的细胞的存活，而减少了学习早期产生的细胞的存活。这些结果强调了学习诱导的变化在记忆中的成年细胞存活中的重要性。此外，他们提供了认知功能老化的可能的神经机制的新见解，并表明，改变导致神经发生的步骤可能参与个人记忆能力的确定。
Aging is accompanied by an alteration of spatial memory, which has been related to an alteration in hippocampal plasticity. Within the dentate gyrus, new neurons are generated throughout the entire life of an individual. This neurogenesis seems to play a role in hippocampal-mediated learning and learning-induced changes in neurogenesis have been proposed to be involved in memory. However, in aged rats, little is known on the influence of learning on the early development of the adult-born neurons and on the possible involvement of learning-induced changes in neurogenesis in age-related memory deficits. To address this issue, we took advantage of the existence of spontaneous individual differences for performances observed in aged subjects in the water maze. In this task, learning can be divided into two phases, an early phase during which performances quickly improve, and a late phase during which asymptotic levels of performances are reached. We show that the influence of spatial learning on the survival of the newly born cells depends on their birth date and the memory abilities of the aged rats. In aged rats with preserved spatial memory, learning increases the survival of cells generated before learning whereas it decreases survival of cells produced during the early phase of learning. These results highlight the importance of learning-induced changes in adult-born cell survival in memory. Furthermore, they provide new insights on the possible neural mechanisms of aging of cognitive functions and show that an alteration to the steps leading to neurogenesis may be involved in the determination of individual memory abilities.