Laboratoire Biologie Structurale Intégrée, Institut de Recherche Interdisciplinaire USR3078, CNRS, Parc scientifique 50 avenue de Halley, 59658 Villeneuve d'Ascq, France.
Behav Brain Res. 2013 Jul 15;249:1-7. doi: 10.1016/j.bbr.2013.04.015. Epub 2013 Apr 19.
A sensorimotor restriction, for instance in patients confined to bed, induces an impairment in motor function, which could be due to structural and functional reorganization of the sensorimotor cortex. Hindlimb unloading (HU) is a rodent model used to reproduce the chronic weightless bearing and reduction in hindlimb movement. In this study, we determined whether a 14-day period of HU in adult rats leads to dendritic spine plasticity. For this purpose, we visualized a large number of spines on pyramidal neurons located in superficial and deep layers of the cortex within the hindpaw representation area, by means of confocal microscopy. Spines were classified according to their shape, as stubby, thin, mushroom, or filopodium. Spine density was increased (+26%) after HU. The increase concerned mainly filopodium spines (+82%) and mushrooms (+33%), whereas no change was noticed for stubby and thin spines. Spine length was decreased, whatever their shape. Head diameter evolved differently depending on the layer: it was increased in superficial layers and decreased in deeper ones. These results indicate that morphological changes accompany functional reorganization of motor cortex in response to a decrease in sensorimotor function during adulthood.
例如，感觉运动受限会导致卧床患者运动功能受损，这可能是由于感觉运动皮层的结构和功能重组所致。下肢悬吊（HU）是一种用于复制慢性无重力承重和减少后肢运动的啮齿动物模型。在这项研究中，我们确定了成年大鼠 14 天的 HU 是否会导致树突棘可塑性。为此，我们通过共聚焦显微镜可视化了位于后爪代表区域内皮层浅层和深层的锥体神经元上的大量棘突。根据其形状将棘突分为短粗、细、蘑菇或丝状。HU 后棘突密度增加（增加 26%）。增加主要涉及丝状棘突（增加 82%）和蘑菇状棘突（增加 33%），而短粗和细棘突没有变化。无论形状如何，棘突长度都减少了。头部直径根据层的不同而不同：在浅层增加，在更深层减少。这些结果表明，形态变化伴随着运动皮层的功能重组，以响应成年后感觉运动功能的下降。
