From caffeine, cigarettes and alcohol, to more extreme drugs.

從咖啡、香菸、酒精，到毒品。

But as the most commonly used illicit drug in North America, where does marijuana fit in?

但在北美洲最普遍使用的非法毒品大麻，又是怎樣呢？

And how exactly does it effect your brain?

大麻對腦部的影響有哪些？

First, we need to understand how the brain functions.

首先，我們必須先了解大腦的機制。

Your neurons are the cells that process information in the brain,

神經細胞會把訊息傳導到腦部。

by releasing chemicals called "neuro-transmitters" from the axon of one neuron to the dendrite of another.

大腦藉由釋放「神經傳導物質」將訊息從一個神經元軸突傳送到另一個。

They change the electrical charge of the receiving neuron, consequently exciting or inhibiting it.

神經傳導物質會改變接收神經元的電荷，並激活或抑制它們。

If excited, the signal is passed on.

如果激活了，信息將被傳送。

Though it sounds simple, these signals work together and the effect is quickly compounded into complex configurations within milliseconds, flushing over the entire brain.

雖然這聽起來很簡單，但這些訊號彼此合作，在幾毫秒內迅速配製複雜的結構達到效果，並傳遍整個大腦。

This is what happens every single time you think, breath, or move.

這就是每當你思考、呼吸或移動時腦部運作的情況。

So what is going on inside your brain when you are smoking marijuana?

那當你吸大麻時，腦部會如何運作呢？

Well, unlike alcohol which contains molecules nothing like those in our body.

不像酒精分子與人體分子完全不同，可被排出體外。

Cannabis contains molecules that resemble those produced in our very own brains.

大麻分子與我們腦部分子十分相似。

Cannabinoids, though naturally these cannabinoids circulate in much lower quantities compared to the large influx imposed by smoking.

體內的自然微量大麻素比由抽大麻造成的量來得少得多。

Specifically the chemical Tetrahydrocannabinol, or THC, resembles a natural transmitter called Anandamide.

特別是化學物質「四氫大麻酚」，簡稱 THC。它與一種天然傳導物質「阿南達胺」很相似。

These cannabinoids are specialized neurotransmitters released by neurons having just fired.

大麻素就是神經元發射後所產生的特殊神經傳遞素。

Neurons temporarily becomes unresponsive after firing, to prevent them from overreacting or being to dominant.

原本神經元發射後會暫時失效，可防止它們反應過度或過度活躍。

This allows your brain to function in a calm and controlled manner.

這使你的大腦得以冷靜及受控的運作。

But cannabinoids interrupt this approach in some parts of the brain.

但大麻素會擾亂腦中這方面的運作。

Instead, they remove the refractory period of neurons, that are already active and cause your thoughts, imagination and perception to utterly magnify itself.

大麻素會去除掉原本神經元的不反應期，並加強放大你的幻想與知覺。

This means once you begin your train of thought, it becomes the most significant and profound thing ever.

這意味著當你開始思考，任何事都會變得非常顯著且深刻。

You can't see the big picture or even recall your last epiphany, because you are caught up in the momentum of a particular idea, and your neurons keep firing.

你看不到事情的全面，也沒有任何一絲記憶，只能想著特定一件事，神經元也會持續活躍。

Until a new idea takes hold, and you go off on a new tangent.

直到新的想法闖入，你的思考才切到新的路線。

These cannabinoids also effect the levels of dopamine and norephinephrine in your brain.

大麻素也會影響大腦中多巴胺與正腎上腺素的量。

Often leading to a sense of euphoria, relaxation, pain modulation and general enhancement of an experience, though sometimes causing anxiety.

這通常會造成興奮、肌肉鬆弛，並增強疼痛調節和感知，但有時也會引起焦慮。

Furthermore, there are cannabinoid receptors in areas controlling short term memory, learning, coordination, movement control and higher cognitive functions.

此外，有些大麻素也存在於某些控制短期記憶、學習、協調、運動控制和高級認知功能的區域。

Got a burning question you want answered? Ask it in the comments or on facebook and twitter.

有迫切想知道答案的問題嗎？於留言區或前往 Facebook 和 Twitter 留言吧！

And subscribe for more weekly science videos.

別忘記訂閱收看每週最新科學影片。