There are two neuron-level mechanisms proposed to underlie neural plasticity: recruiting neurons nearby to support the lost function (ipsilesional plasticity) and uncovering latent pathways that can assume the function that was lost (contralesional plasticity). While both patterns have been demonstrated in patient groups following injury, the specific mechanisms underlying each mode of plasticity are poorly understood. In a retrospective case series of 13 patients, we utilize a novel paradigm that analyzes serial fMRI scans in patients harboring intrinsic brain tumors that vary in location and growth kinetics to better understand the mechanisms underlying these two modes of plasticity in the human primary motor cortex. Twelve patients in our series had some degree of primary motor cortex plasticity, an area previously thought to have limited plasticity. Patients harboring smaller lesions with slower growth kinetics and increasing distance from the primary motor region demonstrated recruitment of ipsilateral motor regions. Conversely, larger, faster-growing lesions in close proximity to the primary motor region were associated with activation of the contralesional primary motor cortex, along with increased activation of the supplementary motor area. These data increase our understanding of the adaptive abilities of the brain and may lead to improved treatment strategies for those suffering from motor loss secondary to brain injuries.

中文翻译：

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原发性脑肿瘤患者原发性运动皮层的可塑性。

提出了两种在神经可塑性基础上的神经元级机制：在附近募集神经元以支持丧失的功能（肢体可塑性）和揭示可能承担丧失的功能的潜在途径（contraesional可塑性）。虽然这两种模式已在受伤后的患者组中得到证实，但对每种可塑性模式背后的具体机制了解甚少。在回顾性病例系列的13例患者中，我们利用一种新颖的范例来分析具有功能和位置动力学变化的内在性脑肿瘤的患者的连续fMRI扫描，以更好地了解人类主要运动皮层的这两种可塑性模式的机制。我们系列中的12名患者具有一定程度的原发性运动皮层可塑性，以前认为塑性有限的区域。病灶较小，生长动力学较慢且距原发运动区的距离增加的患者表现出同侧运动区的募集。相反，紧靠初级运动区的较大，生长较快的病变与对侧初级运动皮层的激活以及辅助运动区的激活增加有关。这些数据增加了我们对大脑适应能力的理解，并可能导致针对继发于脑损伤的运动丧失的患者改善治疗策略。靠近初级运动区的较快生长的病变与对侧初级运动皮层的激活以及辅助运动区的激活增加有关。这些数据增加了我们对大脑适应能力的理解，并可能导致针对继发于脑损伤的运动丧失的患者改善治疗策略。靠近初级运动区的较快生长的病变与对侧初级运动皮层的激活以及辅助运动区的激活增加有关。这些数据增加了我们对大脑适应能力的理解，并可能导致针对继发于脑损伤的运动丧失的患者改善治疗策略。