Hairston Ilana S, Little Milton T M, Scanlon Michael D, Barakat Monique T, Palmer Theo D, Sapolsky Robert M, Heller H Craig
Psychology Department, University of California, Berkeley, 94720, USA.
J Neurophysiol. 2005 Dec;94(6):4224-33. doi: 10.1152/jn.00218.2005. Epub 2005 Jul 13.
Sleep deprivation impairs hippocampal-dependent learning, which, in turn, is associated with increased survival of newborn cells in the hippocampus. We tested whether the deleterious effects of sleep restriction on hippocampus-dependent memory were associated with reduced cell survival in the hippocampus. We show that sleep restriction impaired hippocampus-dependent learning and abolished learning-induced neurogenesis. Animals were trained in a water maze on either a spatial learning (hippocampus-dependent) task or a nonspatial (hippocampus-independent) task for 4 days. Sleep-restricted animals were kept awake for one-half of their rest phase on each of the training days. Consistent with previous reports, animals trained on the hippocampus-dependent task expressed increased survival of newborn cells in comparison with animals trained on the hippocampus-independent task. This increase was abolished by sleep restriction that caused overall reduced cell survival in all animals. Sleep restriction also selectively impaired spatial learning while performance in the nonspatial task was, surprisingly, improved. Further analysis showed that in both training groups fully rested animals applied a spatial strategy irrespective of task requirements; this strategy interfered with performance in the nonspatial task. Conversely, in sleep-restricted animals, this preferred spatial strategy was eliminated, favoring the use of nonspatial information, and hence improving performance in the nonspatial task. These findings suggest that sleep loss altered behavioral strategies to those that do not depend on the hippocampus, concomitantly reversing the neurogenic effects of hippocampus-dependent learning.
睡眠剥夺会损害依赖海马体的学习能力，而这又与海马体中新生细胞存活率的增加有关。我们测试了睡眠限制对依赖海马体记忆的有害影响是否与海马体中细胞存活率降低有关。我们发现，睡眠限制会损害依赖海马体的学习能力，并消除学习诱导的神经发生。动物在水迷宫中接受为期4天的空间学习（依赖海马体）任务或非空间（不依赖海马体）任务训练。在每个训练日，睡眠受限的动物在其休息阶段的一半时间内保持清醒。与之前的报告一致，接受依赖海马体任务训练的动物与接受不依赖海马体任务训练的动物相比，新生细胞的存活率有所增加。这种增加被睡眠限制所消除，睡眠限制导致所有动物的细胞存活率总体降低。睡眠限制还选择性地损害了空间学习能力，而令人惊讶的是，非空间任务的表现得到了改善。进一步分析表明，在两个训练组中，完全休息的动物无论任务要求如何都会采用空间策略；这种策略会干扰非空间任务的表现。相反，在睡眠受限的动物中，这种偏好的空间策略被消除，有利于使用非空间信息，从而提高了非空间任务的表现。这些发现表明，睡眠不足会将行为策略改变为不依赖海马体的策略，同时逆转依赖海马体学习的神经发生效应。
