Dynamic regulation of cortical information processing and energy expenditure by food availability

我们吃什么会极大地影响我们的大脑功能。大多数人都经历过当他们饿了的时候注意力不集中或脾气暴躁的感觉。这是因为我们的大脑需要许多卡路里才能发挥作用。尽管大脑只占身体质量的2%，但大脑消耗的能量却占我们每天消耗的能量的20%，这意味着，按重量计算，大脑是能量最昂贵的器官。当食物摄入量减少时，肌肉等器官为了节省能量而降低了自己的表现。我们预测大脑没有什么不同，当食物摄入量减少时，为了节省能量，大脑也应该同样降低其表现。我们将在老鼠身上测试这一预测，作为哺乳动物大脑功能的动物模型，使我们能够研究这一过程背后的细胞机制。为了做到这一点，我们将把老鼠的卡路里摄入量减少20%-25%，并记录它们大脑中神经元的活动，特别是处理视觉信息的视觉皮质。我们的初步数据显示，卡路里限制会降低视觉皮质的功能，这与我们的预测一致。在我们的研究中，我们将进一步探索这些变化，并检查当卡路里摄入量减少时，它们是否有助于大脑节省能量。接下来，我们想要了解负责将卡路里摄入量的变化与大脑功能的变化联系起来的分子和激素。最后，我们想了解在卡路里限制期间大脑功能的减少在多大程度上实际上会影响行为。具体地说，在我们的研究中，我们将测试卡路里限制期间视觉皮质功能的降低如何影响小鼠的视觉能力。总体而言，我们的研究将帮助我们了解卡路里摄入量如何影响大脑功能和能量消耗。这项工作将对了解如何最好地调整人类饮食以改善终身认知功能具有重要意义，这将有利于生活质量和经济生产率，并将降低医疗成本。我们的研究还可能揭示改善大脑功能和能量利用的潜在药物靶点。

What we eat greatly impacts our brain function. Most people have experienced the feeling of being less able to concentrate or getting grumpy when they are hungry. This is because our brains need many calories to function. Despite only comprising 2% of the body mass, the brain utilizes 20% of the energy we consume daily, meaning that, by weight, it is the most energetically expensive organ. When food intake is reduced, organs such as muscles, reduce their performance in order to save energy. We predict that the brain is no different, and that when food intake is reduced, the brain should similarly reduce its performance in order to save energy. We will test this prediction in mice, as an animal model of mammalian brain function that allows us to study the cellular mechanisms underlying this process. To do so, we will reduce the calorie intake of mice by 20-25% and will record the activity of neurons within their brain, specifically within the visual cortex, which processes visual information. Our preliminary data show that calorie restriction reduces the function of the visual cortex, in line with our prediction. In our study, we will further explore these changes, and examine if they help the brain to save energy when calorie intake is reduced. We next want to understand the molecules and hormones responsible for linking changes in caloric intake with changes in brain function. Finally, we want to understand to what extent reductions in brain function during calorie restriction actually impact behaviour. Specifically, in our study, we will test how reductions in the function of the visual cortex during calorie restriction affect visual ability in mice. Overall, our study will help us to understand how calorie intake impacts brain function and energy consumption. This work will be important for understanding how best to adapt human diet to improve life-long cognitive function, which would benefit quality of life and economic productivity, and would reduce health costs. Our study may also reveal potential drug targets for improving brain function and energy use.