Thermal nociception in adult Drosophila:: behavioral characterization and the role of the painless gene
Thermal nociception in adult Drosophila:: behavioral characterization and the role of the painless gene
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DOI：
10.1111/j.1601-183x.2006.00213.x
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发表时间：
2006-11-01
影响因子：
2.5
通讯作者：
Guo, A. K.
中科院分区：
文献类型：
--
作者：
Xu, S. Y.;Cang, C. L.;Guo, A. K.
伤害性感受是应该避免的伤害警告，对动物具有重要的保护作用。在这项研究中，我们证明了成年果蝇通过跳跃反应来避免有毒的热量。为了定量分析这种伤害性行为，我们开发了两种分析方法。在二氧化碳激光分析中，当激光加热果蝇的腹部时，果蝇会表现出这种行为。跳跃潜伏期的一致性符合良好的伤害性测定的重要标准。在热板试验中，苍蝇迅速跳跃以逃离高温的铜板(摄氏45度)。我们的结果表明，与哺乳动物一样，跳跃反应的潜伏期与刺激强度成反比，无害的温度感觉不会引发这种伤害性行为。为了探索伤害性感受的遗传机制，我们在两种方法中都检测了几个突变体。突变体无痛(1)的异常伤害行为表明，无痛，一种对果蝇幼虫的伤害感受必不可少的基因，也是成年果蝇热伤害感受所必需的。无痛在周围神经系统和胸神经节的某些神经元中表达，也在特定的大脑结构--蘑菇体中表达。然而，化学或遗传对蘑菇体的侮辱不会影响伤害性行为，这表明不同的无痛表达神经元在热伤害性感受中发挥着不同的作用。此外，No-Bridge(KS49)，一个在原大脑桥中有结构缺陷的突变体，对有害的热量表现出缺陷的反应。因此，我们的结果验证了成年果蝇是研究热伤害感觉遗传机制的有用模型。
Nociception, warning of injury that should be avoided, serves an important protective function in animals. In this study, we show that adult Drosophila avoids noxious heat by a jump response. To quantitatively analyze this nociceptive behavior, we developed two assays. In the CO2 laser beam assay, flies exhibit this behavior when a laser beam heats their abdomens. The consistency of the jump latency in this assay meets an important criterion for a good nociceptive assay. In the hot plate assay, flies jump quickly to escape from a hot copper plate (> 45 degrees C). Our results demonstrate that, as in mammals, the latency of the jump response is inversely related to stimulus intensity, and innoxious thermosensation does not elicit this nociceptive behavior. To explore the genetic mechanisms of nociception, we examined several mutants in both assays. Abnormal nociceptive behavior of a mutant, painless(1), indicates that painless, a gene essential for nociception in Drosophila larvae, is also required for thermal nociception in adult flies. painless is expressed in certain neurons of the peripheral nervous system and thoracic ganglia, as well as in the definite brain structures, the mushroom bodies. However, chemical or genetic insults to the mushroom bodies do not influence the nociceptive behavior, suggesting that different painless-expressing neurons play diverse roles in thermal nociception. Additionally, no-bridge(KS49), a mutant that has a structural defect in the protocerebral bridge, shows defective response to noxious heat. Thus, our results validate adult Drosophila as a useful model to study the genetic mechanisms of thermal nociception.