updating its withered and damaged cells with new, improved units.

自動更新受損的細胞單位

That may sound like science fiction,

科幻小說般的情節，卻極有可能成真

but it's a potential reality scientists are investigating right now.

這也正是科學家們在探討的事項

Will our brains one day be able to self-repair?

究竟，大腦會不會有自動修復的一天？

It's well known that embryonic cells in our young developing brains

我們知道胚胎細胞，在發育初期的腦部

produce new neurons,

製造腦神經元

the microscopic units that make up the brain's tissue.

這些是構成腦部組織的微小單位

Those newly generated neurons migrate to various parts of the developing brain,

在發育中的腦裡，新的神經元移至各處

making it self-organize into different structures.

自行組成不同構造

But until recently,

直到最近

scientists thought cell production came to an abrupt halt soon after this initial growth,

科學家們認為腦細胞的製造， 會在最初的生長後突然停止

leading them to conclude that neurological diseases,

由此推斷出腦神經元疾病，

like Alzheimer's and Parkinson's,

如阿茲海默症、帕金森氏症

and damaging events, like strokes, are irreversible.

以及中風等讓腦部受損的事件，都是永久的傷害

But a series of recent discoveries

然而，最近一連串的新發現

has revealed that adult brains actually do continue to produce new cells

證實成人的腦至少在腦部的三個特別區塊

in at least three specialized locations.

可以再生新的神經元

This process, known as neurogenesis,

此過程稱為「神經生成」

involves dedicated brain cells, called neural stem cells

其中包含的腦細胞，被稱作神經幹細胞

and progenitor cells,

及祖細胞

which manufacture new neurons or replace the old ones.

這些細胞製造出新的神經元，取代舊有的

The three regions where neurogenesis has been discovered

而有「神經生成」的三個區域也被發現

are the dentate gyrus, associated with learning and memory,

分別是與學習和記憶有關的「齒狀回」

the subventricular zone, which may supply neurons to the olfactory bulb

以及為傳輸嗅覺資訊至腦部的嗅球

for communication between the nose and brain,

提供神經元的「腦室下區」

and the striatum, which helps manage movement.

和管理動作的「紋狀體」

Scientists don't yet have a good grasp on exactly what role

然而，科學家們至今尚未能掌握

neurogenesis plays in any of these regions,

「神經生成」在這三區裡扮演的角色

or why they have this ability that's absent from the rest of the brain,

或是這三個區會與眾不同的原因

but the mere presence of a mechanism to grown new neurons in the adult brain

單就「成人的腦能再生神經元」這個機制的存在

opens up an amazing possibility.

就開啟了驚人的可能性

Could we harness that mechanism to get the brain to heal its scars

我們是否能將此機制用於腦部的傷口的癒合呢

similar to how new skin grows to patch up a wound,

就像皮膚上的傷口會癒合

or a broken bone stitches itself back together?

斷掉的骨頭能重新長好

So here's where we stand.

所以我們想

Certain proteins and other small molecules that mimick those proteins

某些蛋白質及其他可模擬出蛋白質的小分子

can be administered to the brain

可在腦部作用

to make neural stem cells and progenitor cells

促使神經幹細胞及祖細胞

produce more neurons in those three locations.

在腦部的三個區域中產生新的神經元

This technique still needs improvement

這項技術仍待加強

so that the cells reproduce more efficiently

讓細胞再生更具效率

and more cells survive.

且有較高的存活率

But research shows that progenitor cells from these areas

但科學家發現，這三區的祖細胞

can actually migrate to places where injury has occurred

其實會移動到腦部受損的部分

and give rise to new neurons there.

並在那產生新的神經元

And another promising possible approach

而另一項極有可能成功的方法

is to transplant healthy human neural stem cells,

便是以實驗室培養的健康的

which are cultured in a laboratory, to injured tissue,

人類神經幹細胞，移植到受傷的組織

like we can do with skin.

就像皮膚移植一樣

Scientists are currently experimenting

現今科學家們仍在嘗試

to determine whether transplanted donor cells can divide, differentiate

究竟移植的細胞是否能分裂、分化

and successfully give rise to new neurons in a damaged brain.

成功的為受傷的腦部增添新的神經元

They've also discovered

他們也發現

that we might be able to teach other kinds of brain cells,

或許我們能教其他的腦細胞

such as astrocytes or oligodendrocytes

如星形膠質細胞、少突膠質細胞

to behave like neural stem cells and start generating neurons, too.

像神經幹細胞一樣，產生新的神經元

So, a couple of decades from now will our brains be able to self-repair?

所以，幾十年後，我們的腦是否能自我修復呢？

We can't say for sure,

一切還很難說

but that has become one of the major goals of regenerative medicine.

但這儼然已是再生醫學的重要標的

The human brain has 100 billion neurons

人類的大腦有1兆個神經元

and we're still figuring out the wiring behind this huge biological motherboard.

而我們仍在試著了解這龐大的生物主機板， 是如何佈線的

But everyday, research on neurogenesis brings us closer to that reboot switch.

神經生成的研究， 正帶領著我們邁向腦部能重開機的一天