Tyrosine is needed to synthesize dopamine and norepinephrine, and tryptophan is needed to synthesize the neurotransmitter serotonin.

酪氨酸是合成多巴胺、去甲肾上腺所必须；色氨酸是合成神经递质血所必须。

Serotonin is one of the oldest neurotransmitters.

“血是最古老神经递质之一。”

Specifically, the genes that express your serotonin receptors.

更准确地说，是表达血受体。

One of those relief-providing chemicals is serotonin, a neurotransmitter.

提供缓解化学物质之一是血，一种神经递质。

Patients with schizophrenia often have elevated levels of serotonin in the brain.

患有精神裂症病人大脑通常拥有较高血水平。

One widespread impression among the public is that depression is caused by having too little serotonin.

公众普遍认为抑郁症是由血少而引起。

Because MDMA affects serotonin, a nervous system chemical.

这是为MDMA会影响一种名为“血”神经系统化学物质。

And finally, higher levels of serotonin are associated with greater confidence.

最后，血水平越高，越能加强自信。

First, it optimizes the levels of neurotransmitters like serotonin, norepinephrine, and dopamine.

首先，它能优化神经递质水平，如血、去甲肾上腺和多巴胺。

First off, serotonin isn't the only neurotransmitter that plays a role.

首先，5-羟色胺不是唯一起作用神经递质。

You've probably heard of a couple of these neurotransmitters—serotonin and norepinephrine.

或许你可能听几种神经递质介质——5-羟色胺与降肾上腺。

Is it Cortisol, testosterone, insulin or serotonin. You've got three seconds, go!

是皮质醇、睾丸、胰岛还是血？你有3秒钟时间，开始！

Well, exercise releases an important blend of mood altering hormones including dopamine, serotonin and norepinephrine.

通锻炼，人体会释放一些重要情绪调节激，包括多巴胺、血和降肾上腺。

It contains tryptophan, a chemical in the brain that is used to produce serotonin.

它含有色氨酸，即一种在大脑中用来产生血化学物质。

They lose their sensitivity to serotonin and norepinephrine. Which leads to...? Impaired cognitive function.

会失去对5 羟色胺和正肾上腺敏感性 那就会引起认知功能受损。

Once it hits your bloodstream, it targets three major neurotransmitters — serotonin, dopamine, and norepinephrine.

一旦它进入你血液，它就会瞄准三种主要神经递质——血、多巴胺和去甲肾上腺。

Aside from its positive effects on dopamine, exercise also elevates levels of norepinephrine and serotonin.

除了可以增加多巴胺外，锻炼还能提高体内去甲肾上腺以及 5-羟色胺水平。

The other looks at how a brain chemical called serotonin regulates the patience of rats.

而另一个则是研究大脑中一种叫血化学物质如何调整老鼠耐受力。

But that serotonin also makes it easier for the itch signal to be re-triggered again.

但是血也使得瘙痒信号更容易再次被触发。

What happens is your serotonin levels are down and melatonin which makes you sleepy, that's up.

于是血水平下降，褪黑上升，让你犯困。