Research Centre on Animal Cognition (CRCA), Centre for Integrative Biology (CBI), Toulouse University, CNRS, UPS , Toulouse 31062 , France.
Philos Trans R Soc Lond B Biol Sci. 2019 Jun 10;374(1774):20180368. doi: 10.1098/rstb.2018.0368.
Learning and memory are indisputably key features of animal success. Using information about past experiences is critical for optimal decision-making in a fluctuating environment. Those abilities are usually believed to be limited to organisms with a nervous system, precluding their existence in non-neural organisms. However, recent studies showed that the slime mould Physarum polycephalum, despite being unicellular, displays habituation, a simple form of learning. In this paper, we studied the possible substrate of both short- and long-term habituation in slime moulds. We habituated slime moulds to sodium, a known repellent, using a 6 day training and turned them into a dormant state named sclerotia. Those slime moulds were then revived and tested for habituation. We showed that information acquired during the training was preserved through the dormant stage as slime moulds still showed habituation after a one-month dormancy period. Chemical analyses indicated a continuous uptake of sodium during the process of habituation and showed that sodium was retained throughout the dormant stage. Lastly, we showed that memory inception via constrained absorption of sodium for 2 h elicited habituation. Our results suggest that slime moulds absorbed the repellent and used it as a 'circulating memory'. This article is part of the theme issue 'Liquid brains, solid brains: How distributed cognitive architectures process information'.
学习和记忆无疑是动物成功的关键特征。利用过去经验的信息对于在波动的环境中做出最佳决策至关重要。这些能力通常被认为仅限于具有神经系统的生物，排除了它们在非神经生物中的存在。然而，最近的研究表明，尽管黏菌是单细胞生物，但它表现出习惯化，这是一种简单的学习形式。在本文中，我们研究了黏菌短期和长期习惯化的可能基质。我们使用 6 天的训练使黏菌对钠（一种已知的驱避剂）产生习惯化，并将其转化为休眠状态，称为菌核。然后，我们将这些黏菌复活并测试其习惯化。我们表明，在休眠阶段，训练过程中获得的信息得以保留，因为黏菌在休眠一个月后仍表现出习惯化。化学分析表明，在习惯化过程中持续吸收钠，并且表明钠在整个休眠阶段都被保留。最后，我们表明，通过限制吸收 2 小时的钠来引发记忆，会引起习惯化。我们的结果表明，黏菌吸收了驱避剂，并将其用作“循环记忆”。本文是主题为“液态大脑，固态大脑：分布式认知架构如何处理信息”的一部分。
