肠道通过迷走神经助力大脑记忆形成

美国南加州大学的研究团队发现了肠道与记忆形成之间的神经生物学机制。1由Scott Kanoski教授领导的研究发表在《自然通讯》杂志上，揭示营养物质如何通过迷走神经向大脑传递信号，帮助将食物相关的经历转化为持久记忆。1

实验显示，当大鼠进食营养丰富的食物后，其海马体的记忆活动明显增强，这与大脑释放乙酰胆碱密切相关。1乙酰胆碱是一种神经递质，在大脑记录新信息和形成记忆的过程中发挥关键作用。1研究人员阻断迷走神经后发现，乙酰胆碱水平不再上升，大鼠记住食物位置的能力随之下降，这证实了迷走神经在该过程中的必要性。1

值得注意的是，大脑能够区分食物的味道与其营养价值。1低热量或无热量的甜味液体虽然能刺激味觉，但无法激活与记忆相关的神经通路，而含有营养的食物则能有效激活这些通路。1此外，长期高脂肪高糖饮食会削弱肠-海马体之间的通讯，导致记忆响应持续降低。1研究暗示迷走神经刺激或改善肠道健康可能是保护记忆和认知功能的潜在治疗途径。1

Researchers at the University of Southern California have discovered that the gut communicates with the brain through the vagus nerve to transform food-related experiences into lasting memories.1 Led by Professor Scott Kanoski, the team found that when rats consumed nutrient-rich food, neural activity in the hippocampus—the brain's memory center—increased significantly, whereas low-calorie or non-caloric sweetened liquids produced no such effect.1 The study, published in Nature Communications, reveals that the brain distinguishes between taste and actual nutritional value, activating memory-related pathways only in response to genuinely nutritious meals.1

The mechanism works through a specific biochemical pathway: nutrients in food stimulate the gut to release signals that travel via the vagus nerve to the hippocampus, where they trigger the release of acetylcholine, a neurotransmitter essential for recording new information and forming memories.1 When researchers blocked the vagus nerve in their experiments, acetylcholine levels failed to rise and the animals' ability to remember food locations declined.1 This finding underscores the critical role of gut-brain communication in memory formation.

The research also reveals a troubling consequence of poor diet. Prolonged consumption of high-fat, high-sugar foods weakens communication between the gut and hippocampus, causing a sustained decline in memory responses that persists even after switching to a healthier diet.1 The findings suggest potential therapeutic approaches: stimulating the vagus nerve or improving gut health may support memory and cognitive function protection.1