Department of Biochemistry and Molecular Biophysics and the Howard Hughes Medical Institute, College of Physicians and Surgeons, Columbia University, New York, New York 10032, USA.
Nature. 2010 Dec 2;468(7324):686-90. doi: 10.1038/nature09554.
Drosophila show innate olfactory-driven behaviours that are observed in naive animals without previous learning or experience, suggesting that the neural circuits that mediate these behaviours are genetically programmed. Despite the numerical simplicity of the fly nervous system, features of the anatomical organization of the fly brain often confound the delineation of these circuits. Here we identify a neural circuit responsive to cVA, a pheromone that elicits sexually dimorphic behaviours. We have combined neural tracing using an improved photoactivatable green fluorescent protein (PA-GFP) with electrophysiology, optical imaging and laser-mediated microlesioning to map this circuit from the activation of sensory neurons in the antennae to the excitation of descending neurons in the ventral nerve cord. This circuit is concise and minimally comprises four neurons, connected by three synapses. Three of these neurons are overtly dimorphic and identify a male-specific neuropil that integrates inputs from multiple sensory systems and sends outputs to the ventral nerve cord. This neural pathway suggests a means by which a single pheromone can elicit different behaviours in the two sexes.
果蝇表现出先天的嗅觉驱动行为，这些行为在没有先前学习或经验的情况下就能被观察到，这表明介导这些行为的神经回路是由基因编程的。尽管果蝇的神经系统在数量上很简单，但果蝇大脑的解剖组织特征常常使这些回路的划分变得复杂。在这里，我们鉴定了一个对 cVA 有反应的神经回路，cVA 是一种能引起性别二态性行为的信息素。我们结合了使用改良的光激活绿色荧光蛋白 (PA-GFP) 的神经追踪技术，以及电生理学、光学成像和激光介导的微损伤技术，从触角中的感觉神经元的激活到腹神经索中下行神经元的兴奋，来绘制这个回路。这个回路简洁明了，由四个神经元组成，通过三个突触连接。其中三个神经元明显是二态性的，并确定了一个雄性特异性神经丛，它整合来自多个感觉系统的输入，并将输出发送到腹神经索。这条神经通路表明，一种单一的信息素可以在两种性别中引发不同的行为。
