东京大学研究人员在3月12日出版的《自然》杂志上报告说，他们经实验确认果蝇触角根部的感觉神经能和人类的耳朵一样感知声音和重力，其与声音和重力相关的脑神经回路与人类极为相似。
研究人员用绿色荧光蛋白从果蝇触角的运动着手，确定了果蝇感知声音和重力的区域。这一区域是由约500个神经细胞排列而成的“Johnston’s organ”。
雄性果蝇有听到“情歌”就开始寻找雌性果蝇的习性，但研究人员在实验中发现，如果使“Johnston’s organ”中与声音相关的神经细胞不发挥作用，再用扬声器播放情歌，雄果蝇就不会像通常一样向扬声器聚拢。
在针对果蝇受惊吓后会向上逃走的习性进行实验时，研究人员让“Johnston’s organ”中与重力相关的神经细胞不发挥作用，结果果蝇大多数情况下不再向上飞。
研究人员还证实，果蝇大脑在比较左右两侧传来声音的机制方面，以及感受重力后将这一信息传递到大脑其他区域的机制都与人脑非常相似。
研究人员解释说，在生物的进化过程中，人类与果蝇在距今约6亿年前分道扬镳。人和果蝇之所以有相似的脑神经回路，或许是因为两者在进化时都在寻求对处理声音和重力信息来说最合适的构造。
此前研究曾表明，果蝇感知气味、光线和味道的大脑机制和人类相似，加上这次的研究成果，果蝇在对生物来说最重要的5种感知的大脑机制方面都与人类相似。（生物谷Bioon.com）
生物谷推荐原始出处：
Nature 458, 165-171 (12 March 2009) | doi:10.1038/nature07810
The neural basis of Drosophila gravity-sensing and hearing
Azusa Kamikouchi1,2,3,6, Hidehiko K. Inagaki2,6,7, Thomas Effertz1,4, Oliver Hendrich1,4, André Fiala4,5, Martin C. G?pfert1,4 & Kei Ito2
1 Sensory Systems Laboratory, Institute of Zoology, University of Cologne, 50923 Cologne, Germany
2 Institute of Molecular and Cellular Biosciences, University of Tokyo, Yayoi, Bunkyo-ku, 113-0032 Tokyo, Japan
3 School of Life Sciences, Tokyo University of Pharmacy and Life Sciences, 1432-1, Horinouchi, Hachioji, 192-0392 Tokyo, Japan
4 Johann-Friedrich-Blumenbach-Institute, University of G?ttingen, 37073 G?ttingen, Germany
5 Theodor-Boveri-Institute, Department of Genetics and Neurobiology, Julius-Maximilians-University of Würzburg, Am Hubland, 97074 Würzburg, Germany
6 These authors contributed equally to this work.
7 Present address: Division of Biology 216-76, California Institute of Technology, Pasadena, California 91125, USA.
The neural substrates that the fruitfly Drosophila uses to sense smell, taste and light share marked structural and functional similarities with ours, providing attractive models to dissect sensory stimulus processing. Here we focus on two of the remaining and less understood prime sensory modalities: graviception and hearing. We show that the fly has implemented both sensory modalities into a single system, Johnston's organ, which houses specialized clusters of mechanosensory neurons, each of which monitors specific movements of the antenna. Gravity- and sound-sensitive neurons differ in their response characteristics, and only the latter express the candidate mechanotransducer channel NompC. The two neural subsets also differ in their central projections, feeding into neural pathways that are reminiscent of the vestibular and auditory pathways in our brain. By establishing the Drosophila counterparts of these sensory systems, our findings provide the basis for a systematic functional and molecular dissection of how different mechanosensory stimuli are detected and processed.
