美國能源部勞倫斯伯克利國家實驗室和加州大學的研究人員利用一種全新的光激活蛋白和基因表達技術(shù)，觀察到斑馬魚幼蟲尾鰭控制游動的一種神經(jīng)細胞,。這項研究發(fā)表在9月17日Nature雜志上,。
該研究利用了一種幾年前開發(fā)出來的光激活蛋白，可以通過基因工程的手段使該蛋白的基因在神經(jīng)元或其他細胞中表達,，并起到光學開關(guān)的作用,。為了測試這種光激活開關(guān)，研究人員利用該蛋白尋找控制斑馬魚幼蟲神經(jīng)回路中的神經(jīng)細胞,。
首先,，研究人員利用幾百條斑馬魚的基因組隨機地表達光激活蛋白，發(fā)現(xiàn)在肌肉細胞,，骨細胞或中樞神經(jīng)細胞有光激活蛋白表達,。接著研究人員選擇那些在脊髓神經(jīng)細胞中表達光激活蛋白的斑馬魚——已知這些神經(jīng)細胞控制斑馬魚的運動。
然后,，研究人員在用光源照射斑馬魚幼蟲,，發(fā)現(xiàn)這些斑馬魚同時擺動尾鰭開始游動。進一步分析表明,，這些斑馬魚的一種名為Kolmer-Agduhr的神經(jīng)元中光激活蛋白都得以表達,。(生物谷Bioon.com)
生物谷推薦原始出處：
Nature 461, 407-410 (17 September 2009) | doi:10.1038/nature08323
Optogenetic dissection of a behavioural module in the vertebrate spinal cord
Claire Wyart1,5, Filippo Del Bene2,5, Erica Warp1, Ethan K. Scott2,6, Dirk Trauner3, Herwig Baier2 & Ehud Y. Isacoff1,4
1 Helen Wills Neuroscience Institute and Department of Molecular and Cell Biology, University of California in Berkeley, Berkeley, California 94720, USA
2 Department of Physiology, Program in Neuroscience, University of California in San Francisco, San Francisco, California 94158-2324, USA
3 Department of Chemistry, Ludwig Maximilians-Universit?t, Munich, Germany
4 Physical Bioscience Division and Material Science Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
5 These authors contributed equally to this work.
6 Present address: School of Biomedical Sciences, University of Queensland, Queensland 4072, Australia.
Locomotion relies on neural networks called central pattern generators (CPGs) that generate periodic motor commands for rhythmic movements1. In vertebrates, the excitatory synaptic drive for inducing the spinal CPG can originate from either supraspinal glutamatergic inputs or from within the spinal cord2, 3. Here we identify a spinal input to the CPG that drives spontaneous locomotion using a combination of intersectional gene expression and optogenetics4 in zebrafish larvae. The photo-stimulation of one specific cell type was sufficient to induce a symmetrical tail beating sequence that mimics spontaneous slow forward swimming. This neuron is the Kolmer–Agduhr cell5, which extends cilia into the central cerebrospinal-fluid-containing canal of the spinal cord and has an ipsilateral ascending axon that terminates in a series of consecutive segments6. Genetically silencing Kolmer–Agduhr cells reduced the frequency of spontaneous free swimming, indicating that activity of Kolmer–Agduhr cells provides necessary tone for spontaneous forward swimming. Kolmer–Agduhr cells have been known for over 75 years, but their function has been mysterious. Our results reveal that during early development in zebrafish these cells provide a positive drive to the spinal CPG for spontaneous locomotion.
