听力文摘：什么是氨基丁酸化学物质?（在线收听）

What Is The GABA Chemical?

什么是氨基丁酸化学物质？

What would it be like if wearing a soft cotton t-shirt felt like your skin was being scrubbed with a Brillo pad? For people who suffer from a condition called central pain, such pain is all too familiar.

如果你穿了一件柔软的棉制体恤衫，但是感觉一直被钢丝摩擦，那是一种什么感受？那些遭遇过的人称之为中枢疼痛，这是种通病。

Central Pain on this moment of science.

当今科学里的中枢疼痛。

No one’s sure why some people suffer agonizing pain at the slightest touch, but the secret may lie in an area of the brain called the thalamus, which acts as a gateway for all sensory messages processed by the brain. Nerve cells known as neurons relay messages to the thalamus, which passes the messages to a set of neurons that carry the messages to other areas of the brain.

没有人确切地知道为什么有些人只是被轻微地触碰就会感到剧痛，但是一定是和大脑中一个称为丘脑的地方有关，那是用大脑处理感知信息的通道。神经元这样的神经细胞把信息传递到丘脑，然后丘脑再把信息传递到一套能够把信息带到大脑其他地方的神经元。

Different sets of neurons bring pain and touch signals into the thalamus, but both types of messages are passed to other areas of the brain by one set of outgoing neurons.

不同套的神经元把疼痛和触碰信号带到丘脑，但是不同类型的信息都能通过一套流出的神经元传递到大脑的其他地方。

So how does the brain distinguish between signals of touch and pain? Messages of touch trigger the release of a chemical called GABA, which diminishes the intensity of the outgoing message. But messages of pain don’t seem to cause GABA to be released, so they come through at full strength.

因此大脑如何区分触碰和疼痛的信号？触碰的信息引起一种称为氨基丁酸的化学物质的释放，使得流出信息的密度降低。但是疼痛的信息看上去不能让氨基丁酸释放，这样的话，流出信息就会最大量地涌出。

GABA might be muting some messages by altering their length. Messages of touch might cause a brief burst of information and then be shut off by GABA, while messages of pain continue to fire, unimpeded by GABA. In people who suffer from central pain, GABA might NOT be released in response to messages of touch. With no GABA to turn the touch signal down, every signal of touch may be read as one of pain.

氨基丁酸通过改变信息的长度使得有些信息通透。触碰的信息可能会引起信息激增，然后被氨基丁酸切断；而疼痛信息继续增加，不受氨基丁酸的影响。那些遭受中枢疼痛的人中，氨基丁酸可能在有了触碰信息的时候不会释放。没有能降低触碰信息的氨基丁酸了，每一个触碰信号可能都被解读成疼痛。