据2月26日的《科学》杂志报道说,将胚胎神经元移植到幼年小鼠的脑中可导致一个新的“关键期”的开始,在此关键期中,脑子重新恢复了其对传入的感觉性资讯的变化进行调节的不同寻常的能力。 被人最深入研究的脑的可塑性的形式之一是视觉系统。 在出生之后不久的一个特别的时期内,如果某只眼睛被一直捂盖着的话,脑的视觉皮层能够进行重新连接。那些从前专门负责接受来自被捂盖眼睛的信息的神经元将会改由那只有功用的眼睛来控制。
Derek Southwell及其同僚将未充分发育的神经元(来自出生前不久的神经元)植入到年龄略大的新生小鼠的脑中。 随着该小鼠的发育,它们的视觉皮层经历了正常的关键期。 然而,那些移植的细胞接着在某一较后的时间开始了一个新的关键期,且该关键期与植入的年龄不一致的神经元的关键期相一致。 这些植入的神经元是抑制性的神经元,这意味着它们会抑制有关的信号,而非放大这些信号。 研究人员提出,抑制性神经元的植入也许可为人们提供一种修复受损脑回路的方法。(生物谷Bioon.com)
生物谷推荐原始出处:
Science 26 February 2010: DOI: 10.1126/science.1183962
Cortical Plasticity Induced by Inhibitory Neuron Transplantation
Derek G. Southwell,1 Robert C. Froemke,2 Arturo Alvarez-Buylla,1,* Michael P. Stryker,3,* Sunil P. Gandhi3,*
Critical periods are times of pronounced brain plasticity. During a critical period in the postnatal development of the visual cortex, the occlusion of one eye triggers a rapid reorganization of neuronal responses, a process known as ocular dominance plasticity. We have shown that the transplantation of inhibitory neurons induces ocular dominance plasticity after the critical period. Transplanted inhibitory neurons receive excitatory synapses, make inhibitory synapses onto host cortical neurons, and promote plasticity when they reach a cellular age equivalent to that of endogenous inhibitory neurons during the normal critical period. These findings suggest that ocular dominance plasticity is regulated by the execution of a maturational program intrinsic to inhibitory neurons. By inducing plasticity, inhibitory neuron transplantation may facilitate brain repair.
1 Department of Neurological Surgery and the Eli and Edythe Broad Center of Regenerative Medicine and Stem Cell Research, University of California, San Francisco, 513 Parnassus Avenue, San Francisco, CA 94143, USA.
2 Department of Otolaryngology, University of California, San Francisco, 513 Parnassus Avenue, San Francisco, CA 94143, USA.
3 Department of Physiology, University of California, San Francisco, 513 Parnassus Avenue, San Francisco, CA 94143, USA.