Slaby Pavel, Bartos Premysl, Karas Jakub, Netusil Radek, Tomanova Kateřina, Vacha Martin
Faculty of Science, Institute of Experimental Biology, Masaryk University, Brno, Czechia.
Front Behav Neurosci. 2018 May 28;12:107. doi: 10.3389/fnbeh.2018.00107. eCollection 2018.
Diverse animal species perceive Earth's magnetism and use their magnetic sense to orientate and navigate. Even non-migrating insects such as fruit flies and cockroaches have been shown to exploit the flavoprotein Cryptochrome (Cry) as a likely magnetic direction sensor; however, the transduction mechanism remains unknown. In order to work as a system to steer insect flight or control locomotion, the magnetic sense must transmit the signal from the receptor cells to the brain at a similar speed to other sensory systems, presumably within hundreds of milliseconds or less. So far, no electrophysiological or behavioral study has tackled the problem of the transduction delay in case of Cry-mediated magnetoreception specifically. Here, using a novel aversive conditioning assay on an American cockroach, we show that magnetic transduction is executed within a sub-second time span. A series of inter-stimulus intervals between conditioned stimuli (magnetic North rotation) and unconditioned aversive stimuli (hot air flow) provides original evidence that Cry-mediated magnetic transduction is sufficiently rapid to mediate insect orientation.
多种动物能够感知地球磁场，并利用它们的磁感来定向和导航。即使是像果蝇和蟑螂这样不迁徙的昆虫，也已被证明会利用黄素蛋白隐花色素（Cry）作为一种可能的磁向传感器；然而，其转导机制仍然未知。为了作为一个引导昆虫飞行或控制运动的系统发挥作用，磁感必须以与其他感觉系统相似的速度将信号从受体细胞传递到大脑，大概在几百毫秒或更短的时间内。到目前为止，还没有电生理或行为学研究专门解决Cry介导的磁感受情况下的转导延迟问题。在这里，我们对美洲蟑螂使用一种新的厌恶条件反射测定法，表明磁转导在亚秒级时间范围内完成。条件刺激（磁北旋转）和非条件厌恶刺激（热气流）之间的一系列刺激间隔提供了原始证据，表明Cry介导的磁转导足够迅速，能够介导昆虫的定向。
