Bidirectional thermotaxis in Caenorhabditis elegans is mediated by distinct sensorimotor strategies driven by the AFD thermosensory neurons
Bidirectional thermotaxis in Caenorhabditis elegans is mediated by distinct sensorimotor strategies driven by the AFD thermosensory neurons
复制标题
秀丽隐杆线虫的双向趋热性是由 AFD 热感觉神经元驱动的不同感觉运动策略介导的
DOI：
10.1073/pnas.1315205111
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发表时间：
2014-02-18
影响因子：
11.1
通讯作者：
Samuel, Aravinthan D. T.
中科院分区：
文献类型：
--
作者：
Luo, Linjiao;Cook, Nathan;Samuel, Aravinthan D. T.
线虫秀丽隐杆线虫（Caelophabditis elegans）朝向通过长期温度暴露确定的优选温度设定点（Ts）导航。在趋热性过程中，蠕虫在温度高于Ts（负趋热性）时沿温度梯度向下迁移，并在Ts附近进行等温跟踪。在某些条件下，蠕虫在低于Ts的温度梯度上迁移（正趋热性）。在这里，我们分析了积极和消极的趋热性T-S研究特定的神经元，已被提出参与趋热性使用遗传消融，行为跟踪，钙成像的作用。我们发现差异的积极和消极的趋热性的策略。负趋热性是通过偏置频率的重定向机动（转弯和逆转）和偏置方向的重定向机动朝向较冷的温度。相反，正趋热性只会使重定向运动的方向偏向更温暖的温度。我们发现，AFD热敏神经元驱动积极和消极的趋热性。位于AFD突触后的AIY中间神经元可能介导T-s以下由负趋热性向正趋热性的转变。我们建议，多个趋热行为，每个定义由一组不同的感觉运动转换，从AFD的热敏神经元发出。AFD学习并存储首选温度的记忆，检测温度梯度，并通过灵活使用下游电路在每个温度状态下驱动适当的趋热行为。
The nematode Caenorhabditis elegans navigates toward a preferred temperature setpoint (T-s) determined by long-term temperature exposure. During thermotaxis, the worm migrates down temperature gradients at temperatures above T-s (negative thermotaxis) and performs isothermal tracking near T-s. Under some conditions, the worm migrates up temperature gradients below T-s (positive thermotaxis). Here, we analyze positive and negative thermotaxis toward T-s to study the role of specific neurons that have been proposed to be involved in thermotaxis using genetic ablation, behavioral tracking, and calcium imaging. We find differences in the strategies for positive and negative thermotaxis. Negative thermotaxis is achieved through biasing the frequency of reorientation maneuvers (turns and reversal turns) and biasing the direction of reorientation maneuvers toward colder temperatures. Positive thermotaxis, in contrast, biases only the direction of reorientation maneuvers toward warmer temperatures. We find that the AFD thermosensory neuron drives both positive and negative thermotaxis. The AIY interneuron, which is postsynaptic to AFD, may mediate the switch from negative to positive thermotaxis below T-s. We propose that multiple thermotactic behaviors, each defined by a distinct set of sensorimotor transformations, emanate from the AFD thermosensory neurons. AFD learns and stores the memory of preferred temperatures, detects temperature gradients, and drives the appropriate thermotactic behavior in each temperature regime by the flexible use of downstream circuits.