Brain optimization, compensation and plasticity

对成人大脑的损伤通常会造成永久性的行为和解剖学后果。脑损伤的一个主要影响是导致运动能力的丧失。随着时间的推移，大多数人会发展出补偿性运动策略来替代失去的运动能力。补偿策略与原始动作有明显的区别。我的研究表明，大多数脑损伤后的恢复是对失去的运动功能的补偿，而不是对原始运动的恢复。因此，我提出了大脑优化理论，认为成年人的大脑功能处于最佳状态，任何形式的损伤都会永久性地破坏其原始功能。因此，随着时间的推移，失去的功能被替代的补偿性运动策略所取代。我的研究方向是通过熟练的动作分析来确定补偿策略和相关的可塑性。在拟议的研究中，我将使用实验室大鼠(1)表征用于克服损伤后原发性运动障碍的代偿策略，(2)量化身体远端和近端部位的代偿调整，(3)确定运动功能代偿的神经基础。然后，该模型将用于描述(1)补偿策略如何随不同类型的损伤而变化，(2)经验如何促进补偿或真正的恢复，(3)生理影响如何影响补偿。我还将对老鼠和人类的代偿行为进行比较分析。本研究的总体假设是，除非失去的组织被替换，补偿策略介导功能恢复。这些研究将阐明大脑和行为如何在受伤后发生变化的机制。由于代偿可能与那些促进行为发育和健康衰老的神经机制一样，是由相同的神经机制介导的，因此对代偿的理解可以使我们更全面地了解神经系统的功能。

Damage to the adult brain usually has permanent behavioural and anatomical consequences. A major effect of brain damage is to cause loss of movement capacity. Most individuals, over time, develop compensatory movement strategies that substitute for lost motor capacity. Compensatory strategies are clearly recognizable and distinguishable from original movements. My work has shown that most recovery after brain injury represents compensation of the lost motor function rather than restoration of original movements. Therefore, I propose the brain optimization theory stating that the adult brain functions at the best possible level, and that any form of injury permanently disrupts its original function. Thus, lost function is replaced by alternative, compensatory movement strategies over time. My research is directed toward identifying compensatory strategies and associated plasticity by using skilled movement analysis. In the proposed research, I will use laboratory rats to (1) characterize compensatory strategies used to overcome primary motor disability after injury, (2) quantify compensatory adjustments made by distal and proximal body parts, (3) determine the neural basis of compensation of motor function. The model will then be used to describe (1) how compensatory strategies change with different kinds of injury, (2) how experience can facilitate compensation or genuine restoration, (3) how physiological influences affect compensation. I will also pursue comparative analysis of compensatory behaviour in rats and human subjects. The overall hypothesis of this research is that, unless the lost tissue is replaced, compensatory strategies mediate recovery of function. These studies will elucidate mechanisms of how the brain and behaviour change in response to injury. Because compensation may be mediated by the same neural mechanisms as those that contribute to behavioural development and healthy aging, an understanding of compensation can lead to insights into nervous system function more generally.