Short-term adaptation and temporal processing in the cryophilic response of Caenorhabditis elegans
Short-term adaptation and temporal processing in the cryophilic response of Caenorhabditis elegans
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DOI：
10.1152/jn.00892.2006
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发表时间：
2007-03-01
影响因子：
2.5
通讯作者：
Samuel, Aravinthan D. T.
中科院分区：
文献类型：
--
作者：
Clark, Damon A.;Gabel, Christopher V.;Samuel, Aravinthan D. T.
在空间温度梯度导航时，线虫C。秀丽线虫向较冷的温度迁移，直到它达到其先前的培养温度，表现出嗜冷运动。影响嗜冷运动的策略是有偏随机游走：C。elegans通过调节重新定向的概率来延长（缩短）向下（向上）空间热梯度定向的向前运动的周期。在这里，我们分析的时间感觉处理器，使嗜冷运动量化的运动，个别蠕虫受到定义的温度波形。我们表明，步骤增加温度小至0.05摄氏度导致短暂的增加，然后逐渐适应基线水平的重新定位的概率;温度下降导致类似的，但反转的响应。短期适应是感觉系统的一般特性，允许生物体在广泛的操作范围内保持对感觉变化的敏感性。在嗜冷运动过程中C. elegans还使用其适应性反应的时间动态来计算具有精密灵敏度的逐渐温度变化的时间导数。基于时间导数，蜗杆确定其在每个向前运动期间在空间热梯度中如何定向。我们发现，在ttx-3突变体中，嗜冷反应的操作范围延伸到较低的温度，这会影响AIY中间神经元的发育。我们发现，时间的感觉处理器的嗜冷反应的EAT-4谷氨酸囊泡转运蛋白突变的影响。调节嗜冷反应的操作范围和执行嗜冷反应可以具有单独的神经机制。
When navigating spatial thermal gradients, the nematode C. elegans migrates toward colder temperatures until it reaches its previous cultivation temperature, exhibiting cryophilic movement. The strategy for effecting cryophilic movement is the biased random walk: C. elegans extends ( shortens) periods of forward movement that are directed down ( up) spatial thermal gradients by modulating the probability of reorientation. Here, we analyze the temporal sensory processor that enables cryophilic movement by quantifying the movements of individual worms subjected to defined temperature waveforms. We show that step increases in temperature as small as 0.05 degrees C lead to transient increases in the probability of reorientation followed by gradual adaptation to the baseline level; temperature downsteps leads to similar but inverted responses. Short-term adaptation is a general property of sensory systems, allowing organisms to maintain sensitivity to sensory variations over broad operating ranges. During cryophilic movement C. elegans also uses the temporal dynamics of its adaptive response to compute the time derivative of gradual temperature variations with exquisite sensitivity. On the basis of the time derivative, the worm determines how it is oriented in spatial thermal gradients during each period of forward movement. We show that the operating range of the cryophilic response extends to lower temperatures in ttx-3 mutants, which affects the development of the AIY interneurons. We show that the temporal sensory processor for the cryophilic response is affected by mutation in the EAT-4 glutamate vesicular transporter. Regulating the operating range of the cryophilic response and executing the cryophilic response may have separate neural mechanisms.