生物谷報道：蒼蠅不像人類可以改變環(huán)境溫度,，為了生存它們需要選擇溫度合適的地方活動，美國布蘭迪斯大學(xué)大學(xué)研究認(rèn)為果蠅體內(nèi)有類似熱敏元件的組織,。研究結(jié)果發(fā)表在11日《自然》雜志上,。
生物學(xué)家Paul Garrity和他的同事們發(fā)現(xiàn)，果蠅大腦內(nèi)有4個大型熱感應(yīng)神經(jīng)元細胞,，它們將在環(huán)境溫度高于理想溫度的時候被激活,，溫度改變通過細胞膜上的dTrpA1離子通道，該離子通道本身就擔(dān)任著溫度傳感的職責(zé),。
果蠅能使用腦內(nèi)的傳感器測量環(huán)境溫度,。大型動物使用外圍神經(jīng)元監(jiān)控周圍環(huán)境溫度，而普遍的看法是像果蠅這樣的小型生物也是如此,。研究人員通過使用多種追蹤方式，希望能在果蠅身上找到熱敏感應(yīng)外圍神經(jīng)元,，可是最終數(shù)據(jù)表明,，溫度傳感的關(guān)鍵不在外圍神經(jīng)元，而在果蠅的大腦,。
研究數(shù)據(jù)顯示dTrpA1離子通道可能像火警預(yù)報一樣工作,。當(dāng)果蠅大腦內(nèi)溫度過高，dTrpA1激活內(nèi)部傳感,，讓它們尋找溫度更適宜的地方,。
盡管環(huán)境溫度廣泛影響著人類和動物行為，我們對動物們選擇適宜溫度的神經(jīng)中樞工作原理卻知之甚少,。這項研究使得科學(xué)家們在探知神經(jīng)元細胞如何幫助果蠅尋找合適的溫度以確保生存的進度上邁出了重要的一步,。反之，這些神經(jīng)元通路也能成為攻擊和擾亂動物熱敏行為的武器,，可以應(yīng)用于農(nóng)業(yè)害蟲和傳播瘧疾,、登革熱等疾病的蚊子等的防治,。
全球變暖使大量昆蟲、魚類,、鳥類和哺乳類動物不得不去尋找溫度更適宜的生存環(huán)境,，明白動物神經(jīng)中樞對溫度變換的感應(yīng)機制，能夠更好地理解動物應(yīng)對環(huán)境變化的措施,。此外,，控制這一溫度感應(yīng)機制的蛋白質(zhì)與人類的疼痛、炎癥有關(guān),，深入研究這些蛋白質(zhì)的工作原理將在新的治療方法和藥物研究方面做出重要貢獻,。（生物谷www.bioon.com）
生物谷推薦原始出處：
Nature 11 June 2008 | doi:10.1038/nature07001
An internal thermal sensor controlling temperature preference in Drosophila
Fumika N. Hamada1, Mark Rosenzweig1, Kyeongjin Kang1, Stefan R. Pulver1, Alfredo Ghezzi1, Timothy J. Jegla2 & Paul A. Garrity1
National Center for Behavioral Genomics, Volen Center for Complex Systems, Biology Department, Brandeis University MS-008, 415 South Street, Waltham, Massachusetts 02454, USA
Department of Cell Biology and Institute for Childhood and Neglected Diseases, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, USA
Correspondence to: Paul A. Garrity1 Correspondence and requests for materials should be addressed to P.A.G. (Email: [email protected]).
Animals from flies to humans are able to distinguish subtle gradations in temperature and show strong temperature preferences1, 2, 3, 4. Animals move to environments of optimal temperature and some manipulate the temperature of their surroundings, as humans do using clothing and shelter. Despite the ubiquitous influence of environmental temperature on animal behaviour, the neural circuits and strategies through which animals select a preferred temperature remain largely unknown. Here we identify a small set of warmth-activated anterior cell (AC) neurons located in the Drosophila brain, the function of which is critical for preferred temperature selection. AC neuron activation occurs just above the fly's preferred temperature and depends on dTrpA1, an ion channel that functions as a molecular sensor of warmth. Flies that selectively express dTrpA1 in the AC neurons select normal temperatures, whereas flies in which dTrpA1 function is reduced or eliminated choose warmer temperatures. This internal warmth-sensing pathway promotes avoidance of slightly elevated temperatures and acts together with a distinct pathway for cold avoidance to set the fly's preferred temperature. Thus, flies select a preferred temperature by using a thermal sensing pathway tuned to trigger avoidance of temperatures that deviate even slightly from the preferred temperature. This provides a potentially general strategy for robustly selecting a narrow temperature range optimal for survival.
