A ciliate memorizes the geometry of a swimming arena
A ciliate memorizes the geometry of a swimming arena
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DOI：
10.1098/rsif.2016.0155
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发表时间：
2016-05-01
影响因子：
3.9
通讯作者：
Nakagaki, Toshiyuki
中科院分区：
文献类型：
--
作者：
Kunita, Itsuki;Yamaguchi, Tatsuya;Nakagaki, Toshiyuki
之前对单细胞生物体适应行为的研究已经暗示了它们记忆能力的起源。在这里，我们报告的证据表明，原生动物纤毛虫四膜虫有能力学习其游泳空间的形状和大小。在小水滴中短期限制的细胞被发现在释放时重现环形游泳轨迹。环形轨迹的直径及其持续时间反映了液滴的大小和限制时间。我们提出了一种基于钙离子通道的这种适应性行为的可能机制。在我们的模型中，与限制液滴的壁反复碰撞会导致细胞内钙的缓慢上升，从而导致纤毛搏动反转频率的长期增加。
Previous studies on adaptive behaviour in single-celled organisms have given hints to the origin of their memorizing capacity. Here we report evidence that a protozoan ciliate Tetrahymena has the capacity to learn the shape and size of its swimming space. Cells confined in a small water droplet for a short period were found to recapitulate circular swimming trajectories upon release. The diameter of the circular trajectories and their duration reflected the size of the droplet and the period of confinement. We suggest a possible mechanism for this adaptive behaviour based on a Ca2+ channel. In our model, repeated collisions with the walls of a confining droplet result in a slow rise in intracellular calcium that leads to a long-term increase in the reversal frequency of the ciliary beat.