來自Rockefeller大學的科學家通過研究發(fā)現(xiàn),，在神經(jīng)生物學水平上而言,，人類和蒼蠅的嗅覺系統(tǒng)是很相似的,，這和我們之前預料的很不一樣,。研究結果發(fā)表在了3月19日的在線版《美國國家科學院院刊》（PNAS）上,。
要詢問一個人他聞到了什么味道是一件很容易的事情——例如味道有多強烈？或者它像什么的味道,？——但是對于昆蟲來說就很困難了,。文章的第一作者，Leslie Vosshall副教授的博士后Andreas Keller表示：“對于這些昆蟲是如何對氣味作出反應的行為細節(jié)并不清楚,。”為此,，Keller設計了一個實驗來觀察單個的蒼蠅暴露于不同氣味之下時是如何作出反應的,。結果他和Vosshall發(fā)現(xiàn),，蒼蠅和人類判斷氣味強度的方式是一致的,，但是判斷品質方面卻有所不同,。
蒼蠅的嗅覺系統(tǒng)和人類的類似,，都是由很多神經(jīng)細胞構成的,，它們形成氣味感受器,。每個感受器識別一些氣味，因此這些神經(jīng)細胞結合起來就產(chǎn)生了我們人類以及蒼蠅的嗅覺,。每種動物的感受器數(shù)量是不同的——老鼠大約1200個,，人類大約400個，而果蠅為61個,。Vosshall和Keller希望了解為什么人類和果蠅發(fā)展出了數(shù)量如此不同的氣體感受器。
Vosshall說：“在不同物種中,，感受器數(shù)量對于氣體感官的影響并不十分清楚,。我們發(fā)現(xiàn)盡管確定強度方面人類和蒼蠅類似，但是在氣味種類判斷上還是有差異的,。”或許在兩者的嗅覺系統(tǒng)中產(chǎn)生了基本的變化,，這導致了以上差異的形成,。
部分英文原文：
Published online before print March 19, 2007, 10.1073/pnas.0605321104
PNAS | March 27, 2007 | vol. 104 | no. 13 | 5614-5619
Influence of odorant receptor repertoire on odor perception in humans and fruit flies
Andreas Keller, and Leslie B. Vosshall*
Laboratory of Neurogenetics and Behavior, The Rockefeller University, 1230 York Avenue, Box 63, New York, NY 10021
Edited by Jeffrey C. Hall, Brandeis University, Waltham, MA, and approved February 16, 2007 (received for review June 26, 2006)
The olfactory system is thought to recognize odors with multiple odorant receptors (ORs) that are activated by overlapping sets of odorous molecules, ultimately generating an odor percept in the brain. We investigated how the odor percept differs between humans and Drosophila melanogaster fruit flies, species with very different OR repertoires. We devised high-throughput single fly behavior paradigms to ask how a given OR contributes to the odor percept in Drosophila. Wild-type flies showed dose- and stimulus-dependent responses to 70 of 73 odors tested, whereas mutant flies missing one OR showed subtle behavioral deficits that could not be predicted from the physiological responses of the OR. We measured human and fly judgments of odor intensity and quality and found that intensity perception is conserved between species, whereas quality judgments are species-specific. This study bridges the gap between the activation of olfactory sensory neurons and the odor percept.
behavior | Drosophila | genetics | olfaction | psychophysics
Author contributions: A.K. designed research; A.K. performed research; A.K. and L.B.V. analyzed data; and A.K. and L.B.V. wrote the paper.
