Spaceflight induces changes in the synaptic circuitry of the postnatal developing neocortex
Spaceflight induces changes in the synaptic circuitry of the postnatal developing neocortex
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DOI：
10.1093/cercor/12.8.883
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发表时间：
2002-08-01
期刊：
影响因子：
3.7
通讯作者：
Llinás, R
中科院分区：
文献类型：
--
作者：
DeFelipe, J;Arellano, JI;Llinás, R
成年人新皮层回路模式的建立依赖于各种内在和外在因素，这些因素在发育过程中的改变会导致皮层组织和功能的改变。我们报告了16天的太空飞行[神经实验室使命;从出生后第14天（P14）到P30]对大鼠后肢突触回路的新皮层表现的影响。因此，我们表明，第一次，在微重力的发展导致皮层突触的数量和形态的变化，在一个特定的方式。在层II/III和Va，突触横截面长度显着大于在地面控制动物的飞行动物。飞行动物在第II/III、IV和Va层中也显示出显著较低的突触密度。最大的差异出现在第II/III层，每毫米有3.44亿个突触（减少15.6%）。此外，经过4个月的重新适应地球重力，一些变化消失（即改变是短暂的），而相反，也出现了一些新的差异。例如，在重新适应后，不再观察到II/III层和Va层中突触密度的显著差异，而在IV层中，突触密度在飞行动物中显著增加（差异为每mm 1.85亿个突触（3）或13.4%）。此外，所有观察到的变化只影响不对称的突触，这是已知的兴奋性。这些结果表明，地球重力是一个必要的环境参数正常皮层突触。这些发现对于规划未来的长期太空飞行至关重要。
The establishment of the adult pattern of neocortical circuitry depends on various intrinsic and extrinsic factors, whose modification during development can lead to alterations in cortical organization and function. We report the effect of 16 days of spaceflight [Neurolab mission; from postnatal day 14 (P14) to P30] on the neocortical representation of the hindlimb synaptic circuitry in rats. As a result, we show, for the first time, that development in microgravity leads to changes in the number and morphology of cortical synapses in a laminar-specific manner. In the layers II/III and Va, the synaptic cross-sectional lengths were significantly larger in flight animals than in ground control animals. Flight animals also showed significantly lower synaptic densities in layers II/III, IV and Va. The greatest difference was found in layer II/III, where there was a difference of 344 million synapses per mm(3) (15.6% decrease). Furthermore, after a 4 month period of re-adaptation to terrestrial gravity, some changes disappeared (i.e. the alterations were transient), while conversely, some new differences also appeared. For example, significant differences in synaptic density in layers II/III and Va after re-adaptation were no longer observed, whereas in layer IV the density of synapses increased notably in flight animals (a difference of 185 million synapses per mm(3) or 13.4%). In addition, all the changes observed only affected asymmetrical synapses, which are known to be excitatory. These results indicates that terrestrial gravity is a necessary environmental parameter for normal cortical synaptogenesis. These findings are fundamental in planning future long-term spaceflights.