以光為手段,，科學(xué)家們發(fā)明了一種快速,、精確繪制小鼠大腦功能地圖的方法。他們在日前在線出版的《自然—方法學(xué)》期刊上報(bào)告說,，與電極繪圖法相比,，新方法繪制大腦地圖的速度比電極繪圖法快了多個(gè)數(shù)級，而且,，因?yàn)檫@是一種非侵入性方法,，更適合用于長期研究。新方法也將用于技能學(xué)習(xí)后大腦的重組研究,，以及受傷或疾病后神經(jīng)系統(tǒng)受損害的研究,。
大腦動力地圖的繪制應(yīng)該能夠鑒別出控制身體特定肌肉的運(yùn)動的調(diào)控區(qū)。傳統(tǒng)的繪制方法包括刺激置于大腦表面或置于大腦內(nèi)部的電極,，并同時(shí)監(jiān)測肌肉的反應(yīng),。然而，這些方法都有不利之處,，可能會導(dǎo)致某種傷害,，費(fèi)時(shí)費(fèi)力,，神經(jīng)目標(biāo)的定位也不精確。
Timothy Murphy和同事利用激光激活離子通道,，以光為基礎(chǔ)繪制了小鼠大腦的運(yùn)動區(qū)域,。經(jīng)基因工程改造后，小鼠的神經(jīng)細(xì)胞在離子通道中被激光照亮,，因此不用電極也能看到神經(jīng)細(xì)胞的活動,。然后，將麻醉不醒的小鼠直接放在顯微鏡臺上,，這樣,，當(dāng)激光照射小鼠大腦成百上千的預(yù)定區(qū)域時(shí)，小鼠的動作能夠被快速而準(zhǔn)確地測定,，同時(shí)記錄的肌肉活動或身體移動所產(chǎn)生的結(jié)果產(chǎn)生了可復(fù)制的大腦區(qū)域地圖,，這些區(qū)域控制了相應(yīng)的肌肉。（生物谷Bioon.com）
生物谷推薦原始出處：
Nature Methods 15 February 2009 | doi:10.1038/nmeth.1303
Automated light-based mapping of motor cortex by photoactivation of channelrhodopsin-2 transgenic mice
Oliver G S Ayling1,2,5, Thomas C Harrison1,2,5, Jamie D Boyd3,5, Alexander Goroshkov3 & Timothy H Murphy1,2,4
Abstract
Traditionally, mapping the motor cortex requires electrodes to stimulate the brain and define motor output pathways. Although effective, electrode-based methods are labor-intensive, potentially damaging to the cortex and can have off-target effects. As an alternative method of motor mapping, we photostimulated transgenic mice expressing the light-sensitive ion channel channelrhodopsin-2 in predominantly layer-5 output cortical neurons. We report that optical stimulation of these neurons in vivo using a stage scanning laser system resulted in muscle excitation within 10–20 ms, which can be recorded using implanted electromyogram electrodes or by a noninvasive motion sensor. This approach allowed us to make highly reproducible automated maps of the mouse forelimb and hindlimb motor cortex much faster than with previous methods. We anticipate that the approach will facilitate the study of changes in the location and properties of motor maps after skilled training or damage to the nervous system.
1 Kinsmen Laboratory, Department of Psychiatry, 2255 Wesbrook Mall, Vancouver, V6T 1Z3, Canada.
2 Brain Research Center, 2211 Wesbrook Mall, Vancouver, V6T 1Z3, Canada.
3 In Vivo Imaging Centre, 2350 Health Sciences Mall, Vancouver, V6T 1Z3, Canada.
4 Department of Cellular and Physiological Sciences, University of British Columbia, 2255 Wesbrook Mall, Vancouver, V6T 1Z3, Canada.
5 These authors contributed equally to this work.
