The C. elegans thermosensory neuron AFD responds to warming
The C. elegans thermosensory neuron AFD responds to warming
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DOI：
10.1016/j.cub.2004.06.060
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发表时间：
2004-07-27
期刊：
影响因子：
9.2
通讯作者：
Mori, I
中科院分区：
文献类型：
--
作者：
Kimura, KD;Miyawaki, A;Mori, I
温度感觉的机制远不如对其他环境刺激（如光，气味和味觉）的感觉反应那么了解。嗜热性行为在C.线虫需要能够辨别小至0.05摄氏度的温差，并记住先前培养的温度[1，2]。AFD神经元是趋热性行为所需的唯一主要热敏神经元[3]。遗传分析已经揭示了AFD神经元中温度信息的感觉和/或记忆所需的几种信号转导分子[4-7]，但其生理特性，例如其感觉绝对温度或温度变化的能力，尚不清楚。我们在这里展示了AFD神经元对变暖的反应。AFD神经元胞体内钙离子浓度对升温反应呈一过性升高，而对绝对温度或降温反应不明显。瞬时反应需要TAX-4 cGMP门控阳离子通道的活性，其在AFD神经元的功能中起重要作用[5]。有趣的是，AFD神经元进一步响应高于温度记忆设定的阈值的阶梯式升温。我们建议C.线虫为揭示温度信息感知和记忆的分子机制提供了理想的遗传和生理模型。
The mechanism of temperature sensation is far less understood than the sensory response to other environmental stimuli such as light, odor, and taste. Thermotaxis behavior in C. elegans requires the ability to discriminate temperature differences as small as similar to0.05degreesC and to memorize the previously cultivated temperature [1, 2]. The AFD neuron is the only major thermosensory neuron required for the thermotaxis behavior [3]. Genetic analyses have revealed several signal transduction molecules that are required for the sensation and/or memory of temperature information in the AFD neuron [4-7], but its physiological properties, such as its ability to sense absolute temperature or temperature change, have been unclear. We show here that the AFD neuron responds to warming. Calcium concentration in the cell body of AFD neuron is increased transiently in response to warming, but not to absolute temperature or to cooling. The transient response requires the activity of the TAX-4 cGMP-gated cation channel, which plays an essential role in the function of the AFD neuron [5]. Interestingly, the AFD neuron further responds to step-like warming above a threshold that is set by temperature memory. We suggest that C. elegans provides an ideal model to genetically and physiologically reveal the molecular mechanism for sensation and memory of temperature information.