Functional role and Modulation Of Brain Plasticity

我们活动的目标是了解人类中枢神经系统中塑料变化的功能作用和底物，并开发新的治疗方法来恢复功能。我们的大部分工作都集中在研究人类运动、体感和视觉系统的可塑性变化上。今年，我们确定了触觉辨别技能中的行为痛，一方面与去传入有关，另一方面与去传入有关。在视觉领域，我们发现光剥夺与视觉皮质兴奋性的增加和该区域GABA水平的降低有关。这一发现证明了使用磁共振光谱学在线监测行为人类大脑皮质GABA变化的可能性。关于运动皮质中依赖使用的可塑性，我们发现，通过TMS刺激和通过刺激相邻身体部分表征，可以调节一个身体部位表征的可塑性。我们还开发了两种策略来增强依赖使用的可塑性：通过给予d-苯丙胺和同时给予经颅磁刺激。在与德国研究人员的合作中，我们发现，与没有疼痛的截肢者相比，幻肢疼痛患者的躯体感觉和运动皮质的表征可塑性更显著。在慢性卒中后的康复领域，我们发现一种被称为强制诱导疗法的康复疗法似乎能提高卒中后很长一段时间内偏瘫手臂的使用量。我们对完整的大脑半球和非初级运动区(特别是背侧运动前皮质)参与卒中后运动功能恢复的认识有了进展。在这种认识的基础上，我们开始设计和测试干预措施，以改善人类疾病后的运动障碍。

The goal of our activity is to understand the functional role and substrates underlying plastic changes in the human central nervous system and develop novel therapeutic approaches for recovery of function. Most of our work has focused on the study of plastic changes in the human motor, somatosensory and visual systems. This year, we identified behavioralgains in tactile discriminative skills in one hand associated with deafferentation in the other hand. In the visual domain, we found that light deprivation is associated with an increase in excitability of the visual cortex and a decrease in GABA levels in that region. This finding demonstrates the possibility of online monitoring minute to minute of changes in cortical GABA in behaving humans using magnetic resonance spectroscopy. In relation to use- dependent plasticity in motor cortex, we discovered that it is possible to modulate plasticity in one body part representation by stimulation with TMS and by stimulation of adjacent body part representations. We also developed two strategies to enhance use-dependent plasticity: by administration of d-amphetamine and also by concomitant administration of transacranial magnetic stimulation. In a collaborative effort with German investigators, we found that representational plasticity in somatosensory and motor cortex is more prominent in patients with phantom limb pain than in amputees without pain. In the area of rehabilitation after chronic stroke, we found that a rehabilitation treatment called "constraint induced therapy" appears to enhance the amount of use of the paretic arm long time after stroke. We have advanced in the understanding of the involvement of the intact hemisphere and nonprimary motor areas (particularly dorsal premotor cortex) in recovery of motor function after stroke. On the basis of this understanding, we are starting to design and test interventions to improve motor disability after human diseases.