據(jù)國(guó)外媒體報(bào)道，目前，科學(xué)家使用激光在活果蠅頭部成功鉆出頭發(fā)絲直徑的一個(gè)小孔,，便于觀察研究果蠅大腦的運(yùn)行狀況,。這項(xiàng)研究也將用于測(cè)試蠕蟲(chóng)、螞蟻和老鼠等動(dòng)物,。
顯微觀察活體動(dòng)物使科學(xué)家掌握更多關(guān)于動(dòng)物生物學(xué)特征,，微小透鏡植入活體老鼠身體內(nèi)部，有助于研究人員研究癌癥如何實(shí)時(shí)形成,，并評(píng)估潛在藥物效力,。
科學(xué)家對(duì)小型活體動(dòng)物進(jìn)行“活體鏡檢”經(jīng)常需要很長(zhǎng)時(shí)間，并要求嫻熟的技術(shù)和靈巧度,。目前,，美國(guó)斯坦福大學(xué)系統(tǒng)工程師蘇普里尤-辛哈(Supriyo Sinha)和同事最新研制一種方法，能夠最快地對(duì)活體動(dòng)物進(jìn)行顯微鏡檢查,，僅需不足1秒時(shí)間,，并且主要采用自動(dòng)機(jī)械化方式。
首先,，科學(xué)家冷凍果蠅使其麻醉,，小心翼翼地使用鑷子夾著昆蟲(chóng)，用膠水粘在玻璃纖維上面,，便于固定果蠅的身體和頭部,；然后，使用一種高能脈沖紫外線(xiàn)激光器,，在果蠅頭部鉆出12-350微米的小孔,；最后，他們將實(shí)驗(yàn)手術(shù)后的果蠅放入含鹽溶液,，使解剖大腦組織處于健康狀態(tài),。
科學(xué)家在顯微鏡下分析果蠅大腦活躍性，這只進(jìn)行實(shí)驗(yàn)的果蠅經(jīng)過(guò)基因改良,，體內(nèi)蛋白質(zhì)與鈣離子結(jié)合釋放出綠光,，從而便于研究果蠅的大腦神經(jīng)活動(dòng)特征。
據(jù)悉,，研究人員使用傳統(tǒng)方法描繪大腦活躍性需要較長(zhǎng)的時(shí)間,，有時(shí)需要18小時(shí)，而最新采用的激光鉆孔技術(shù)僅需傳統(tǒng)方法百分之一的時(shí)間,，此外,，可以將多個(gè)實(shí)驗(yàn)活體動(dòng)物同時(shí)進(jìn)行實(shí)驗(yàn)，繪制出它們的大腦活躍狀態(tài),。目前,，這項(xiàng)最新研究發(fā)表在近期出版的美國(guó)《國(guó)家科學(xué)院院刊》上,。 （生物谷Bioon.com）
生物谷推薦的英文摘要
Proceedings of the National Academy of the Sciences of the United States of America doi: 10.1073/pnas.1216287110
High-speed laser microsurgery of alert fruit flies for fluorescence imaging of neural activity
Supriyo Sinhaa，b,，1,， Liang Lianga，b,， Eric T. W. Hoc,， Karel E. Urbanekb， Liqun Luoa,，d,， Thomas M. Baerb，e,，1,， and Mark J. Schnitzera，b,，d,，f,，1
Intravital microscopy is a key means of monitoring cellular function in live organisms,， but surgical preparation of a live animal for microscopy often is time-consuming， requires considerable skill,， and limits experimental throughput. Here we introduce a spatially precise (<1-μm edge precision),， high-speed (<1 s)， largely automated,， and economical protocol for microsurgical preparation of live animals for optical imaging. Using a 193-nm pulsed excimer laser and the fruit fly as a model,， we created observation windows (12- to 350-μm diameters) in the exoskeleton. Through these windows we used two-photon microscopy to image odor-evoked Ca2+ signaling in projection neuron dendrites of the antennal lobe and Kenyon cells of the mushroom body. The impact of a laser-cut window on fly health appears to be substantially less than that of conventional manual dissection， for our imaging durations of up to 18 h were ～5–20 times longer than prior in vivo microscopy studies of hand-dissected flies. This improvement will facilitate studies of numerous questions in neuroscience,， such as those regarding neuronal plasticity or learning and memory. As a control,， we used phototaxis as an exemplary complex behavior in flies and found that laser microsurgery is sufficiently gentle to leave it intact. To demonstrate that our techniques are applicable to other species， we created microsurgical openings in nematodes,， ants,， and the mouse cranium. In conjunction with emerging robotic methods for handling and mounting flies or other small organisms， our rapid,， precisely controllable,， and highly repeatable microsurgical techniques should enable automated， high-throughput preparation of live animals for optical experimentation.
