手機版
for National Geographic News
Published October 3, 2011
Millions of receptors in the nose's smelling organ aren't scattered at random, a new study says. Instead, the receptors congregate in tiny hot spots that help the brain discern good smells from bad ones, among other potential functions.
一(yi)項(xiang)新(xin)的(de)研(yan)究(jiu)表(biao)明(ming)，鼻(bi)腔(qiang)內(nei)數(shu)以(yi)百(bai)萬(wan)計(ji)的(de)嗅(xiu)覺(jiao)受(shou)體(ti)並(bing)不(bu)是(shi)隨(sui)機(ji)分(fen)布(bu)的(de)。而(er)是(shi)聚(ju)集(ji)在(zai)一(yi)些(xie)微(wei)小(xiao)的(de)區(qu)域(yu)裏(li)，它(ta)們(men)可(ke)以(yi)幫(bang)助(zhu)大(da)腦(nao)辨(bian)別(bie)氣(qi)味(wei)的(de)好(hao)壞(huai)，同(tong)時(shi)還(hai)具(ju)備(bei)其(qi)他(ta)一(yi)些(xie)潛(qian)在(zai)的(de)功(gong)能(neng)。
The evidence was gathered by sticking electronic probes up people's noses and measuring the chatter of nasal neurons as subjects were exposed to scents.
shiyanzhengjudeshoujishiyikaoyixiedianzitanzhen。yanjiurenyuanjiangdianzitanzhencharushoushizhebiqiangnei，celiangshoushizhezaixiuwengezhongqiweishixiujiaoshenjingyuansuochanshengdexinhaobianhua。
The findings imply that the pleasantness of a smell is hardwired within our heads, calling into question the impact of life experience on how people perceive smells.
研究結果表明，辨別氣味好壞的神經通路先天就隱藏在人類的大腦裏。問題就是後天經驗是如何對人類嗅覺產生影響的。
"It's both exciting and disturbing," said Don Wilson of the New York University School of Medicine, a neurobiologist who was not involved in the work."It doesn't fit in with what I think or a lot of other researchers think about smell."
“此事既讓人感到興奮又讓人感到疑惑。”從事該項研究工作的紐約大學醫學院神經生物學家Don Wilson說，“這樣的結果與包括我在內的許多專家們對嗅覺的認識相抵觸。”
Instead of the brain processing all scent information, for instance, it seems nasal neurons preprocess some of it—almost as if the nose has its own small brain.
譬如在處理嗅覺信息時，並不是所有的工作都由大腦來承擔。鼻神經元似乎也承擔了部分工作——鼻腔好象自己有自己的小腦一樣。
◆Taking One in the Nose專一的嗅覺感知能力
The human nose contains a postage stamp-size smelling organ, called the olfactory epithelium, at the roof of the nasal cavity.
人類鼻腔的屋頂，有一塊麵積如郵票大小被稱之為“嗅上皮”的嗅覺器官。
By probing mouse noses to measure the firing of nasal neurons, scientists had previously discovered that scent receptors might be organized into groups, similar to the way the tongue has zones armed to detect specific tastes such as sour, sweet, and salty.
科學家們通過對以往大鼠鼻腔神經元活動所做的測定實驗發現，嗅覺受體有可能存在著嗅覺功能上的分工。其分工方式如同舌部，酸、甜、鹹各種味道均有各自的感知區域。
But a rodent's nose has more than 1,200 different types of scent receptors, and even a tiny probe could touch tens of thousands of receptors in one reading, making it hard to get a clear signal.
然而，大鼠鼻腔內有1200多種嗅覺受體。探測器的頂端盡管比針尖還要細，但每次測到的是數以萬計受體神經活動的信息，單個的信號無法辨別。
Humans have roughly 400 different kinds of receptors, however, making the business of sticking probes in noses and plucking out useful information more fruitful.
然而，人類鼻腔內約有400多種不同的嗅覺受體，能更有效地執行探測與識別有用信息的任務。
◆How the Nose Knows氣味是如何分辨的
A team led by neuroscientist Noam Sobel, of the Weizmann Institute of Science in Israel, asked more than 80 people to sniff substances with odors known to be either pleasant or unpleasant across many cultures.
由以色列魏茨曼科學研究所神經學家Noam Sobel領銜的研究小組，要求80餘名具有不同文化背景的被試識別各種已知氣味的好壞。
Ordinary smells can be made up of tens to hundreds of compounds, so Sobel and his colleagues puffed only pure chemicals into the noses of their wired subjects, one scent at a time.
普通氣味是由數十或數百種物質所構成的，因此，Sobel和他的同事每次向聯有探測針的受試者的鼻腔內噴入的是純淨物，每次隻感知一種氣味。
Pooling together 801 neural recordings from people's noses, the team found that some regions of the epithelium are better at detecting scent than other regions. The researchers also found hot spots that are better at interpreting either pleasantness or unpleasantness.
從對人體鼻腔收集到的801項xiang神shen經jing活huo動dong記ji錄lu來lai看kan，小xiao組zu人ren員yuan發fa現xian某mou些xie區qu域yu的de嗅xiu上shang皮pi細xi胞bao比bi其qi它ta區qu域yu的de對dui某mou種zhong氣qi味wei更geng具ju感gan知zhi能neng力li。研yan究jiu人ren員yuan還hai發fa現xian能neng更geng好hao地di識shi別bie氣qi味wei好hao壞huai的de特te定ding區qu域yu。
"To my surprise, this means something about the epithelium is tuned to pick up certain information" in certain zones, New York University's Wilson said."We don't understand what the purposes of those zones are," he added, "but that's exciting."
紐約大學的Wilson說，“真沒想到，嗅覺上皮是一種檢測特定嗅覺信息的結構。雖然這些區域的詳細功能還未查明，但這一結果是值得令人興奮的了。”
The smelling study was published online last week in the journal Nature Neuroscience.
有關研究成果發布於上周網絡版的《自然神經科學》雜誌。
相關閱讀：科學家質疑「味覺分布圖」
原文鏈接：Secrets of Smell: Different Nose Parts for Stinky, Sweet
