Origins of vagal tone

大脑通过迷走神经对心跳施加抑制作用。这被称为心脏迷走神经“张力”。当我们健康时，它是强大的，但当我们生病时，它是脆弱的。它对心脏健康乃至整个身体都有积极的影响。迷走神经张力来自大脑，但是，尽管经过150多年的研究，没有人知道确切的位置。使用一种新技术，我们可以追踪到它的起源。这一重要的基本知识可能会导致改善健康的方法。

The brain exerts a restraining influence over the heartbeat via the vagus nerves. This is known as cardiac vagal ‘tone’. It is strong when we are healthy but weak when we are sick. It has a positive influence on the health of the heart and perhaps the body generally. Vagal tone comes from the brain but, despite over 150 years’ research, nobody knows exactly where. Using a novel technique, we can track down its origins. This important basic knowledge may lead to ways to improve health.