Collaborative Research: Evolutionary Origins of the Brain Energetics and Adaptive Plasticity of Humans

人类大脑的特点是消耗大量的能量和增强的可塑性。这些因素的组合构成了人类最独特的认知能力。大脑的学习能力在儿童时期是最强的，这涉及到新的神经元连接的形成和完善。这一过程是由高能耗率驱动的。本研究项目将确定人类大脑在进化过程中的遗传变化，并探索大脑可塑性发展与新陈代谢之间的因果关系。这个项目的一个主要目的是绘制出人类在不同成熟阶段大脑能量利用的变化。为了实现这一目标，跨学科团队正在使用正电子发射断层扫描从出生到成年阶段的整个发育过程中的脑葡萄糖消耗。这些结果将与RNA和蛋白质数据所呈现的模式相结合，这些数据涉及数千个基因，这些基因在相同发育阶段的不同大脑区域以不同水平表达。研究人员还获得了类人猿和猕猴的蛋白质和神经元形态学发育表达的比较数据，以确定人类大脑发育过程中的分子和细胞变化是否与我们的近亲有明显不同。研究人员希望在大脑能量和大脑可塑性基因中找到协调的表达模式，以证明在人类起源期间，它们的调节机制发生了适应性进化。这一结果将为研究分子机制的组织和功能提供重要线索，这些分子机制支撑着人类大脑的可塑性，正是这种可塑性赋予了人类将经验和学习融入文化生产的非凡能力。通过将注意力集中在大脑能量和大脑可塑性基因上，这些基因在最近的人类祖先中显示出适应性进化，但目前在人类种群中是固定的，该项目将重点放在定义人类认知能力的共享基因上，强化了共同人类的结论。因此，这个项目的结果应该引起公众和各种学科的科学家的兴趣，包括人类学、神经科学、分子进化、生物能量学、内分泌学和儿科学。对生长过程中大脑总能量的实验测定将增强我们理解人类进化史上获得更大大脑所需的年龄特异性权衡的能力，同时也为理解糖尿病等代谢性疾病提供了新的背景。此外，该项目将通过为本科生、研究生和博士后提供培训机会来推进研究和教育。

The human brain is distinguished by costly energetic demands and enhanced plasticity. This combination of factors underlies some of the most unique cognitive capacities of our species. The brain's capacity for learning is greatest during childhood and involves the formation and refinement of new neuronal connections. This process is driven by high rates of energy consumption. This research project will identify the genetic changes during evolution that brought about the human brain and explore the causal link between the development of brain plasticity and metabolism. A major aim of this project involves charting the changes in the brain's energy utilization during the different maturational stages of humans. To accomplish this goal, the interdisciplinary team is using positron emission tomography scans of brain glucose consumption over the course of development from birth to adult stages. These results will be integrated with the patterns presented by RNA and protein data on the thousands of genes that are expressed at changing levels in different brain regions across the same developmental stages. Comparative data on the developmental expression of proteins and neuron morphology in great apes and macaque monkeys are also being obtained to determine whether the progression of molecular and cellular changes in human brain development are distinctively different from our close relatives. The investigators expect to find coordinated expression patterns in brain energetic and brain plasticity genes showing evidence that adaptive evolution occurred in their regulatory machinery during the origin of humans. The results should provide important clues about the organization and function of the molecular machinery that underpins the type of human brain plasticity that gives our species its exceptional capacity to incorporate experience and learning into the production of culture. By focusing attention on brain energetic and brain plasticity genes that show adaptive evolution during recent human ancestry but are currently fixed across human populations, this project's focus on shared genes that define human cognitive abilities reinforces the conclusion of a common humanity. Thus the results of this project should be of interest to the general public and to scientists across a wide variety of disciplines, including anthropology, neuroscience, molecular evolution, bioenergetics, endocrinology and pediatrics. Experimental determination of total brain energetics during growth will enhance our ability to understand the age-specific tradeoffs that the acquisition of larger brains would have required during human evolutionary history, while also providing a new context in which to understand metabolic diseases such as diabetes. Furthermore, this project will advance research and education by providing training opportunities for individuals at the undergraduate, graduate and postdoctoral levels.