Plasticity and variation in brain organization and behaviour

大脑组织和行为的可塑性和变异

• 批准号: RGPIN-2017-06434
• 负责人: Cooke, Dylan
• 金额: $ 1.89万
• 依托单位: Simon Fraser University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2020
• 资助国家: 加拿大
• 起止时间: 2020-01-01 至 2021-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=712228
• 关键词: Plasticity; variation; brain; organization; behaviour

Mammalian brains change throughout the course of a lifetime, but the impact of early life experience has the most profound effect on how the brain is constructed. Specifically, changes in connectivity and organization of the neocortex and the behavior it directs give mammals (humans included) enormous flexibility to adapt to novel environments. Such experience-based plasticity has been demonstrated by enhancing or depriving sensorimotor experience, which generally enlarges and shrinks corresponding body part representations, respectively. For example, trimming the whiskers of rats and mice causes the cortical whisker representation to shrink and that of the forelimb to grow. Training rodents to reach with their forelimbs enlarges the paw representation. The additional neural processing possible in larger representations is thought to underlie enhanced abilities of the corresponding body parts. Most studies of brain plasticity manipulate one variable at a time (e.g. whisker trimming or reach training). But outside of the laboratory, multiple factors together alter the brain and behavior. The complex interaction of factors shaping brains in the real world points to the need for several complementary lines of inquiry. My research program aims to understand how experience shapes the brain. In this proposal, our objectives are to: (1) Determine the extent to which a given genotype can produce variable cortical phenotypes, i.e., how much can the brain change in one lifetime? (2) Determine how multiple complementary changes in experience common in nature, but so far absent in the laboratory interact to shape brain organization. (3) Measure the magnitude of individual variation in sensorimotor skills and relate this to variation in brain organization. The techniques proposed here are well established, but will be implemented in new ways and combinations. This will be the first examination of neural plasticity combining complementary enhancement of one body part (forelimb) and deprivation of another (whiskers). Forelimb reach training will be far more pervasive and will begin far earlier than any previous study. Together these innovations address fundamental questions about the limits of brain plasticity, the impact of complex environments on brain organization, and the relationship between brain organization and skill. Our inquiries will contribute to neuroscientists' understanding of how brains develop and change. As well as being a fundamental question about the nature of humans and other mammals, how animals adapt to complex, changing environments has implications for their responses to climate change and other human impacts on the environment. For humans, the basic question of how changeable and variable the brain is has implications for education, health and societal attitudes about which parts of behavior are fixed and which are mutable.

哺乳动物的大脑在一生中都会发生变化，但早期生活经历的影响对大脑的构造有着最深刻的影响。具体地说，新大脑皮层的连接和组织以及它所指导的行为的变化，给了哺乳动物(包括人类)巨大的灵活性，以适应新的环境。这种基于经验的可塑性已经通过增强或剥夺感觉运动经验来证明，感觉运动经验通常分别放大和缩小相应的身体部分表征。例如，修剪大鼠和小鼠的胡须会导致皮质胡须的代表缩小，而前肢的代表则会生长。训练啮齿类动物用前肢伸展，可以扩大爪子的代表性。在更大的表征中，可能的额外神经处理被认为是增强相应身体部分能力的基础。 大多数关于大脑可塑性的研究一次只处理一个变量(例如，胡须修剪或REACH训练)。但在实验室之外，多种因素共同改变了大脑和行为。现实世界中塑造大脑的因素之间的复杂相互作用表明，需要几条互补的调查路线。我的研究项目旨在了解体验如何塑造大脑。在这项建议中，我们的目标是： (1)确定一个给定的基因可以在多大程度上产生不同的皮质表型，即，大脑在一生中可以改变多少？ (2)确定在自然界中常见的、但到目前为止还没有在实验室中出现的经验中的多种互补变化如何相互作用来塑造大脑组织。 (3)测量感觉运动技能个体差异的大小，并将其与大脑组织的差异联系起来。 这里提出的技术已经很成熟，但将以新的方式和组合来实施。这将是对神经可塑性的第一次检查，结合身体一个部位(前肢)的互补增强和另一个部位(胡须)的缺失。前肢前伸训练将更加普遍，而且比以往的任何研究都要早得多。这些创新共同解决了大脑可塑性的极限、复杂环境对大脑组织的影响以及大脑组织和技能之间的关系等基本问题。我们的调查将有助于神经科学家了解大脑是如何发育和变化的。除了是关于人类和其他哺乳动物本质的一个基本问题外，动物如何适应复杂、不断变化的环境，也关系到它们对气候变化和人类对环境的其他影响的反应。对于人类来说，大脑的多变性和多变性这个基本问题，对教育、健康和社会态度都有影响，比如行为的哪些部分是固定的，哪些是可变的。