Motor Skill Learning Induces Changes in White Matter Microstructure and Myelination
Motor Skill Learning Induces Changes in White Matter Microstructure and Myelination
复制标题
DOI：
10.1523/jneurosci.3048-13.2013
复制
发表时间：
2013-12-11
影响因子：
5.3
通讯作者：
Johansen-Berg, Heidi
中科院分区：
文献类型：
--
作者：
Sampaio-Baptista, Cassandra;Khrapitchev, Alexandre A.;Johansen-Berg, Heidi
学习一种新的运动技能与啮齿动物运动皮质结构和功能的可塑性有关。此外，人类视觉运动学习的神经成像研究表明，白质(WM)可以发生结构可塑性，但这种变化的生物学基础尚不清楚。我们用弥散磁共振分数各向异性(FA)和定量免疫组织化学两种方法评估了运动技能学习对感觉运动皮质WM结构的影响。72只成年(雄性)大鼠被随机分配到三种条件之一(熟练伸展、非熟练伸展和笼养对照)。训练11d后，死后磁共振弥散成像显示，熟练到达组的FA显著高于对照组，尤其是在训练肢体对侧感觉运动皮质下的WM。此外，在熟练接触组中，对侧大脑半球广泛的WM区域的FA与学习速度显著相关。对24只动物(每组8只)进行的免疫组织学分析显示，与对照组相比，熟练学习组受训肢体对侧(但不是同侧)大脑半球运动皮质下的WM髓磷脂染色显著增加。在受过训练的大脑半球内(但未受过训练的大脑半球除外)，髓鞘染色密度与学习速度显著相关。我们的结果表明，学习一种新的运动技能会导致与任务相关的WM通路的结构变化，这些变化可能部分反映了与学习相关的髓鞘形成的增加。
Learning a novel motor skill is associated with well characterized structural and functional plasticity in the rodent motor cortex. Furthermore, neuroimaging studies of visuomotor learning in humans have suggested that structural plasticity can occur in white matter (WM), but the biological basis for such changes is unclear. We assessed the influence of motor skill learning on WM structure within sensorimotor cortex using both diffusion MRI fractional anisotropy (FA) and quantitative immunohistochemistry. Seventy-two adult (male) rats were randomly assigned to one of three conditions (skilled reaching, unskilled reaching, and caged control). After 11 d of training, postmortem diffusion MRI revealed significantly higher FA in the skilled reaching group compared with the control groups, specifically in the WM subjacent to the sensorimotor cortex contralateral to the trained limb. In addition, within the skilled reaching group, FA across widespread regions of WM in the contralateral hemisphere correlated significantly with learning rate. Immunohistological analysis conducted on a subset of 24 animals (eight per group) revealed significantly increased myelin staining in the WM underlying motor cortex in the hemisphere contralateral (but not ipsilateral) to the trained limb for the skilled learning group versus the control groups. Within the trained hemisphere (but not the untrained hemisphere), myelin staining density correlated significantly with learning rate. Our results suggest that learning a novel motor skill induces structural change in task-relevant WM pathways and that these changes may in part reflect learning-related increases in myelination.