Anomalous diffusion on the servosphere: A potential tool for detecting inherent organismal movement patterns.
Anomalous diffusion on the servosphere: A potential tool for detecting inherent organismal movement patterns.
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DOI：
10.1371/journal.pone.0177480
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发表时间：
2017
期刊：
影响因子：
3.7
通讯作者：
Fujisawa R
中科院分区：
文献类型：
--
作者：
Nagaya N;Mizumoto N;Abe MS;Dobata S;Sato R;Fujisawa R
跟踪动物的运动（例如行走）是了解动物如何以及为何在环境中运动以及对外部刺激做出反应的一项重要任务。实现图像分析和数据记录器（例如 GPS）的不同方法已分别用于实验室实验和现场研究。最近，无刺激的动物运动模式引起了越来越多的关注，以寻找其所有运动背后的共同先天特征。然而，由于实验室的空间限制或现场环境的异质性，在没有刺激的情况下很难在广阔且均匀的环境中跟踪运动，这阻碍了我们对固有运动模式的理解。在这里，我们应用了全向跑步机机构或伺服球作为跟踪小动物二维运动的工具，它可以提供均匀的环境和虚拟的无限行走空间。为了验证我们的跟踪系统在评估自由行走行为方面的用途，我们将伺服球上的单个药虫（Armadillidium vulgare）的行走模式与两种类型的实验平坦场地中的行走模式进行了比较。我们的结果表明，伺服球上的行走模式显示出与模拟开放空间的大型竞技场中观察到的相似的扩散特性，并且我们证明，与具有封闭空间的小型竞技场相比，我们的机制提供了更稳健的扩散特性测量。此外，我们还表明，可以从我们的跟踪系统上的自由行走行为中检测到异常扩散特性，包括 Lévy walk。因此，我们新颖的跟踪系统可用于测量固有的运动模式，这将有助于运动生态学、动物行为学和行为科学的研究。
Tracking animal movements such as walking is an essential task for understanding how and why animals move in an environment and respond to external stimuli. Different methods that implemented image analysis and a data logger such as GPS have been used in laboratory experiments and in field studies, respectively. Recently, animal movement patterns without stimuli have attracted an increasing attention in search for common innate characteristics underlying all of their movements. However, it is difficult to track the movements in a vast and homogeneous environment without stimuli because of space constraints in laboratories or environmental heterogeneity in the field, hindering our understanding of inherent movement patterns. Here, we applied an omnidirectional treadmill mechanism, or a servosphere, as a tool for tracking two-dimensional movements of small animals that can provide both a homogenous environment and a virtual infinite space for walking. To validate the use of our tracking system for assessment of the free-walking behavior, we compared walking patterns of individual pillbugs (Armadillidium vulgare) on the servosphere with that in two types of experimental flat arenas. Our results revealed that the walking patterns on the servosphere showed similar diffusive characteristics to those observed in the large arena simulating an open space, and we demonstrated that our mechanism provides more robust measurements of diffusive properties compared to a small arena with enclosure. Moreover, we showed that anomalous diffusion properties, including Lévy walk, can be detected from the free-walking behavior on our tracking system. Thus, our novel tracking system is useful to measure inherent movement patterns, which will contribute to the studies of movement ecology, ethology, and behavioral sciences.