Institute of Medical Psychology and Behavioral Neurobiology and Center for Integrative Neuroscience CIN, University of Tübingen, Tübingen, Germany; Graduate Training Centre of Neuroscience (GTC), International Max Planck Research School (IMPRS) at the University of Tübingen, Germany.
Institute of Medical Psychology and Behavioral Neurobiology and Center for Integrative Neuroscience CIN, University of Tübingen, Tübingen, Germany.
Neurobiol Learn Mem. 2018 Nov;155:306-312. doi: 10.1016/j.nlm.2018.07.012. Epub 2018 Aug 4.
Sleep enhances memory consolidation which has been shown in mammals as well as in invertebrates, like bees and Drosophila. The current study is part of a series of experiments examining whether this memory function of sleep is preserved in Aplysia with an even simpler nervous system. Previous work showed that Aplysia sleep and that sleep after training supports memory on an inhibitory conditioning task ('learning that food is inedible', LFI). Here, we tested whether sleep in Aplysia would also support memory for an extinction learning on the LFI task. Following Acquisition in which animals learned that netted food is inedible, two groups of animals, a Sleep group (n = 15) and a Wake group (n = 16) underwent extinction training. After a 17-hour Retention interval which contained either regular nocturnal sleep or daytime wakefulness (supported by sleep deprivation) animals were retested on the LFI task. Contrary to our hypothesis, the Wake animals showed significantly prolonged food intake behavior on the LFI, indicating that extinction memory in these animals was better than in the Sleep animals. Performance of a control group not subjected to extinction training, ruled out that the superior extinction performance of Wake animals merely reflected forgetting over time of the LFI memory, and also excluding a possible circadian confound. We speculate that wakefulness mainly acts by accelerating active forgetting of the LFI memory after it was labialized through extinction training, thereby facilitating the re-emergence of the original innate behavior of food intake.
睡眠增强了记忆巩固，这在哺乳动物以及无脊椎动物如蜜蜂和果蝇中都有体现。本研究是一系列实验的一部分，旨在检验睡眠的这种记忆功能是否在具有更简单神经系统的海兔中得到保留。先前的工作表明，海兔的睡眠以及训练后的睡眠支持了抑制性条件反射任务（“学习食物不可食用”，LFI）的记忆。在这里，我们测试了海兔的睡眠是否也能支持 LFI 任务的消退学习记忆。在获得性训练中，动物学会了网捕食物是不可食用的，两组动物，睡眠组（n=15）和清醒组（n=16）接受了消退训练。在 17 小时的保留间隔期内，睡眠组包含正常的夜间睡眠，清醒组包含白天的清醒（由剥夺睡眠支持），然后动物在 LFI 任务上进行重新测试。与我们的假设相反，清醒组在 LFI 上表现出明显延长的食物摄入行为，表明这些动物的消退记忆比睡眠组更好。未进行消退训练的对照组的表现排除了清醒组的优越消退表现仅仅反映了 LFI 记忆随时间的遗忘，也排除了可能的昼夜节律混淆。我们推测清醒主要通过加速 LFI 记忆的主动遗忘来发挥作用，从而促进了原始的、天生的食物摄入行为的重新出现。
