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翻譯社

於2004年，Hatten的實驗室早已發現，一種守恆的極性卵白質(par6α)旁邊了，神經元沿著神經膠質導引物的遷移。

大腦發育的進展有點近似歐洲人移民北美洲翻譯最早的拓荒者移民於東海岸，跟著後續的移民浪潮，逐漸朝西部構成聚落翻譯

Hatten and former postdoctoral associate David Solecki, now at St. Jude Children’s Research Hospital, focused on the mechanism of neuronal migration in cortical regions of the brain翻譯社 including the cerebellum翻譯社 hippocampus and cerebral cortex.

此些研究人員發現，par6α群集於位在細胞核正前方，被稱為中央體的要害細胞器中，且影響一種活化肌動球蛋白引擎所需，被稱為肌漿球蛋白輕鏈激酶之酵素的磷酸化翻譯

“Neuronal migration is a very delicate process. The model we’re suggesting is that the actomyosin dynamics are pulling the system forward翻譯社 but they’re close to the nucleus to control this very regulated and precise kind of motility,” Hatten says. “This specialized motility is essential to the formation of neuronal layers in brain. Defects in the process can result in all of the major brain malformations such as lissencephaly as well as a misfiring of the neuronal circuitry as occurs in epilepsy.”

此些研究人員利用了，配備有電荷耦合器件攝影機的轉盤式、共焦顯微鏡，以極高解析度來即時造影神經元的遷移，這使他們得以很具體觀察上述引擎蛋白。

The development of the brain proceeds a little like the European settlement of North America. The earliest pioneers settled on the east coast with subsequent waves of settlers forming communities further and further westward.

In cortical regions of the developing brain翻譯社 generations of young neurons undergo a staged migration as well, with the earliest-born cells staying relatively close to their birthplace and subsequent generations traveling further翻譯社 ultimately stratifying into six neuronal layers in the mature brain.

The researchers used a spinning-disk, confocal microscope, equipped with a CCD camera to image the migration in real time at extremely high resolution翻譯社 allowing them to examine the motor proteins in great detail.

“The complexity of the cell types is so much greater in the brain than in other parts of the body, nothing else compares,” says Mary E. Hatten, head of the Laboratory of Developmental Neurobiology at The Rockefeller University.

原文網址：http://newswire.rockefeller.edu/2009/07/22/new-imaging-studies-reveal-mechanics-of-neuron-migration/

The Hatten lab had already discovered in 2004 that a conserved polarity protein翻譯社 par6α翻譯社 controls the migration of neurons along glial guides. The new research, published July 16 in Neuron翻譯社 identifies the motors regulated by par6α.

「在大腦發育中，由於分歧類型的神經元，在不同的時期被產生。

These motors appear to pull the cell forward in discrete steps: They first assemble in front of the nucleus翻譯社 pull the cell forward, disperse as the cell pauses and then assemble again as the neuron takes another step along the glial guide. The researchers demonstrated that any significant change in the dynamics of actomyosin assembly or par6α activity stops neuron migration in its tracks.

此些引擎顯著以不相關連的步驟，向前拉動神經細胞：首先它們聚集於神經細胞核前，向前拉動神經細胞，當神經細胞中止時散開，而後當神經元沿著神經膠質導引物進行別的一階段時再度群集翻譯此些研究人員證實，在肌動球卵白聚合體或par6α活性動態中的任何明顯轉變，會中斷神經元於其路徑的遷移翻譯

Hatten流傳宣傳：「神經元的遷移是一種極奇妙的曆程。」

Now翻譯社 for the first time翻譯社 imaging studies have identified the “motors” that propel a unique form of cell migration that creates these layers that underlie the formation of synaptic circuitry.

“Since different classes of neurons are born at different times in the brain’s development, neuronal migration is responsible for patterning specific types of cells into particular layers. The normal development of the brain depends critically on this specialized form of motility, which places the neurons in the right layer.”

翻譯：許東榮

美國洛克斐勒大學發育神經生物學實行室主任Mary E. Hatten傳播鼓吹：「這類型細胞在大腦中的複雜性，弘遠於在人體的其他部位翻譯」

Hatten及今朝任職於美國聖裘德兒童研究醫院的前博士後研究同寅David Solecki側重於，包含小腦、海馬迴及大腦皮質等，大腦皮層區域中的神經元遷徙機制。

他們與同僚們研發了，螢光性標記此些渺小神經元中的引擎蛋白，及此些神經細胞沿著，Hatten稱為單軌系統之邁向其方針地的神經膠質纖維遷移時，窺察此些神經元動態的手藝。

今朝(2009年)，造影研究已首度確認了，在突觸迴路層下方，敦促產生上述六個神經元層之怪異神經細胞遷移模式的“引擎”翻譯

在發育中的大腦皮層區，新生代的初期神經元也經歷分階段的遷移，因為最早產生的神經細胞，相對上勾留於接近其出世的地方，而後續的新生代進一步行進，畢竟在成熟大腦中，分層組成六個神經元層翻譯

該於發育大腦中被發現之神經元遷移特化模式的運作軌範，不同於那些指令上皮細胞及成纖維細胞的傳統遷移運作軌範翻譯因為，在後者中的肌動球蛋白引擎，是在相對上遠離神經細胞核“前緣”之遷移神經細胞的頂端翻譯

The researchers found that par6α localizes in a key organelle called the centrosome directly in front of the cell nucleus翻譯社 and effects the phosphorylation of an enzyme called the myosin light chain kinase, needed to activate actomyosin motors.

The mechanics of this specialized form of neuron migration seen in the developing brain are distinct from those that direct the classical migration of epithelial cells and fibroblasts, as actomyosin motors in the latter are at the tip of the migrating cell in a “leading edge” that is relatively far removed from the cell nucleus.

With colleagues翻譯社 they developed techniques to fluorescently label the motor proteins inside the tiny neurons and watch their dynamics as the cells migrate along what Hatten calls a monorail system — glial fibers — toward their destinations.