Rapid and efficient escape behaviors in response to noxious sensory stimuli are essential for protection and survival. Yet, how noxious stimuli are transformed to coordinated escape behaviors remains poorly understood. In Drosophila larvae, noxious stimuli trigger sequential body bending and corkscrew-like rolling behavior. We identified a population of interneurons in the nerve cord of Drosophila, termed Down-and-Back (DnB) neurons, that are activated by noxious heat, promote nociceptive behavior, and are required for robust escape responses to noxious stimuli. Electron microscopic circuit reconstruction shows that DnBs are targets of nociceptive and mechanosensory neurons, are directly presynaptic to pre-motor circuits, and link indirectly to Goro rolling command-like neurons. DnB activation promotes activity in Goro neurons, and coincident inactivation of Goro neurons prevents the rolling sequence but leaves intact body bending motor responses. Thus, activity from nociceptors to DnB interneurons coordinates modular elements of nociceptive escape behavior.

中文翻译：

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伤害性中间神经元控制模块化运动通路以促进果蝇的逃逸行为

对有害感官刺激做出快速有效的逃生行为对于保护和生存至关重要。然而，对有害刺激如何转化为协调的逃避行为仍然知之甚少。在果蝇幼虫中，有害刺激会触发连续的身体弯曲和螺旋状滚动行为。我们在果蝇的神经索中发现了一群中间神经元，称为 Down-and-Back (DnB) 神经元，它们被有害热量激活，促进伤害性行为，并且是对有害刺激的强烈逃逸反应所必需的。电子显微电路重建表明 DnB 是伤害感受和机械感觉神经元的目标，直接与前运动电路突触前连接，并间接连接到 Goro 滚动命令样神经元。DnB 激活促进 Goro 神经元的活动，Goro 神经元的同时失活阻止了滚动序列，但保留了完整的身体弯曲运动反应。因此，从伤害感受器到 DnB 中间神经元的活动协调了伤害性逃避行为的模块化元素。