東京大學(xué)研究人員在3月12日出版的《自然》雜志上報告說,，他們經(jīng)實驗確認(rèn)果蠅觸角根部的感覺神經(jīng)能和人類的耳朵一樣感知聲音和重力,，其與聲音和重力相關(guān)的腦神經(jīng)回路與人類極為相似,。
研究人員用綠色熒光蛋白從果蠅觸角的運動著手，確定了果蠅感知聲音和重力的區(qū)域,。這一區(qū)域是由約500個神經(jīng)細胞排列而成的“Johnston’s organ”,。
雄性果蠅有聽到“情歌”就開始尋找雌性果蠅的習(xí)性，但研究人員在實驗中發(fā)現(xiàn)，如果使“Johnston’s organ”中與聲音相關(guān)的神經(jīng)細胞不發(fā)揮作用,，再用揚聲器播放情歌,，雄果蠅就不會像通常一樣向揚聲器聚攏,。
在針對果蠅受驚嚇后會向上逃走的習(xí)性進行實驗時,，研究人員讓“Johnston’s organ”中與重力相關(guān)的神經(jīng)細胞不發(fā)揮作用，結(jié)果果蠅大多數(shù)情況下不再向上飛,。
研究人員還證實,，果蠅大腦在比較左右兩側(cè)傳來聲音的機制方面，以及感受重力后將這一信息傳遞到大腦其他區(qū)域的機制都與人腦非常相似,。
研究人員解釋說,，在生物的進化過程中，人類與果蠅在距今約6億年前分道揚鑣,。人和果蠅之所以有相似的腦神經(jīng)回路,，或許是因為兩者在進化時都在尋求對處理聲音和重力信息來說最合適的構(gòu)造。
此前研究曾表明,，果蠅感知氣味,、光線和味道的大腦機制和人類相似，加上這次的研究成果,，果蠅在對生物來說最重要的5種感知的大腦機制方面都與人類相似,。（生物谷Bioon.com）
生物谷推薦原始出處：
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.
