Collaborative Proposal: No Brainer: Cognitive-like Behaviors in a Unicellular Slime Mold

大多数生命是无脑的，地球上绝大多数生物完全没有神经元。这些生物包括植物、真菌和细菌（包括非致病性和致病性类型），它们都必须应对与人类相同的问题——在不断变化的世界中做出最佳选择或冒着死亡的风险——但没有大脑甚至简单的神经系统的帮助。该项目将探索其中一种无神经元生物的决策能力，即黏菌多头绒泡菌。特别令人感兴趣的是：(1)多头虾在选择食物来源时如何整合嘈杂的、有时是相互矛盾的信息；(2)其过去的经验（例如，它以前访问过的资源）对其未来选择的结果的作用。由于多头螺是一种宏观的单细胞生物，它可以很容易地操纵和观察，同时保留了与其他无神经元的微观生物相似的特征。因此，它是了解大多数生物如何整合复杂和动态信息的完美模型系统。该项目将在美国最多元化的校园之一（罗格斯-纽瓦克和新泽西理工大学，均位于新泽西州纽瓦克）和澳大利亚悉尼的一个合作实验室培训2名研究生和至少15名本科生和高中生进行综合研究。为鼓励对无神经元生物和其他非传统模式生物的认知过程的研究，将开发用于K-12班级的“动手”、开源演示套件，以实验黏菌的运动和决策。该项目将建立一个全面的实验和理论框架，可用于研究其他无神经元生物的决策，并与有脑动物进行比较，从而促进我们对生物系统中认知过程出现的理解。细胞显微操作和钙显像结合神经生理学和统计物理学的分析工具，将首先研究多头棘球藻细胞膜收缩振荡在其决策过程中的作用。特别是，信息的传递和整合从不同的刺激将被检查。当可用信息嘈杂或相互矛盾时，黏菌决策机制的效率也将受到考验。最后，如果食物总是出现在上坡，那么黏菌的自然正地向性（在重力方向上的运动）是否可以被调节（即在这里被逆转）将被确定。这将表明黏菌具有空间联想学习的能力（这在黏菌中是第一次），并且它的决策过程能够适应它所处环境的特征。在此项目中开发的所有方法、结果和软件将在开放科学框架托管的存储库中免费提供。

Most of life is brainless and the vast majority of organisms on Earth lack neurons altogether. These organisms include plants, fungi, and bacteria (both non-pathogenic and disease-causing types), who all must cope with the same problem as humans - make the best choices in an ever changing world or risk dying - but without the help of a brain or even a simple nervous system. This project will explore the decision-making abilities of one of these neuron-less organisms, the slime mold Physarum polycephalum. Of particular interest is (1) how P. polycephalum integrates noisy and sometimes contradictory information when selecting a food source; and (2) the role of its past experiences (e.g. the resources it has previously visited) on the outcome of its future choices. Because P. polycephalum is a macroscopic unicellular organism, it can be easily manipulated and observed, while retaining similar characteristics to other neuron-less, microscopic creatures. It is therefore a perfect model system to understand how most living beings integrate complex and dynamical information. The project will train 2 graduate students and at least 15 undergraduate and high school students in integrative research at one of the most diverse campuses in the US (Rutgers-Newark and NJIT, both located in Newark, NJ) and at a collaborating lab in Sydney, Australia. "Hands-on", open sourced demonstration kits for K-12 classes to experiment with slime mold locomotion and decision-making will be developed to encourage the study of cognitive processes in neuron-less organisms and other non-traditional model organisms. The proposed project will set up a comprehensive experimental and theoretical framework that can be used beyond the scope of this project to study decision-making in other neuron-less organisms and to establish comparisons with brained animals, thereby advancing our comprehension of the emergence of cognitive processes in biological systems. Cell micromanipulation and calcium imaging combined with analytical tools from neurophysiology and statistical physics will be used to first investigate the role of contractile oscillations of P. polycephalum's cellular plasma membrane in its decision-making process. In particular, the transfer and integration of information from different stimuli will be examined. The efficiency of the slime mold decision-making mechanism when the available information is noisy or contradictory will also be tested. Finally, whether the slime mold's natural positive geotaxis (motion in the direction of gravity) can be conditioned (i.e., reversed here) if food is always present uphill will be determined. This would indicate that the slime mold is capable of spatial associative learning (a first in the slime mold), and that its decision-making process is capable of adapting to the characteristics of the environment through which it moves. All methods, results and software developed during this project will be made freely available on a repository hosted by the Open Science Framework.