科學家們在實驗室中發(fā)現(xiàn)了來自“迷你大腦”的腦電波

For the first time, brain tissue grown in a lab has spontaneously exhibited electrical activity, and it looks startlingly similar to human brain activity. More specifically, it resembles the brain activity of premature babies.

在實驗室中生長的腦組織第一次自發(fā)地表現(xiàn)出電活動，它看起來與人類大腦的活動驚人地相似。更具體地說，它類似于早產兒的大腦活動。

This is a huge discovery that brings on possibilities for studying the early development of brain disorders.

這是一個巨大的發(fā)現(xiàn)，為研究大腦疾病的早期發(fā)展帶來了可能性。

It also has left some scientists feeling hesitant.

這也讓一些科學家感到猶豫。

These lab-grown brains are known as organoids - three-dimensional, miniature, simplified versions of organs grown in a lab for research purposes, such as testing drug responses, or cell development under certain adverse conditions.

這些實驗室培養(yǎng)的大腦被稱為“類器官”——實驗室培養(yǎng)的用于研究目的的器官的三維、微型、簡化版本，例如測試藥物反應或在某些不利條件下細胞發(fā)育。

The research was first presented at a conference back in November 2018, and has now been peer-reviewed and published in Cell Stem Cell.

這項研究最初是在2018年11月的一次會議上提出的，現(xiàn)在已經被同行評審并發(fā)表在《細胞干細胞》雜志上。

"The level of neural activity we are seeing is unprecedented in vitro," says neuroscientist Alysson Muotri from the University of California, San Diego.

“我們在體外看到的神經活動水平是前所未有的，”加州大學圣迭戈分校的神經學家阿里森·穆特里(Alysson Muotri)說。
"We are one step closer to have a model that can actually generate these early stages of a sophisticated neural network."

“我們離建立一個能夠生成復雜神經網絡早期階段的模型又近了一步。”

Muotri has been developing brain organoids in his lab for some years, but this is the first time he and his team have seen anything like human brain activity.

穆特里已經在他的實驗室里開發(fā)了幾年大腦器官，但這是他和他的團隊第一次看到類似人類大腦活動的東西。

They grew the organoids in question from human pluripotent stem cells, or stem cells that can become any other kind of cell. They induced these 'blanks' to develop into cells that make up the cerebral cortex, the region of the brain responsible for really important things like memory, perception, cognition, thought, and sensory processing.

他們從人類多能干細胞(也就是可以成為任何其他類型細胞的干細胞)中培養(yǎng)出有問題的類器官。他們誘導這些“空白”發(fā)育成構成大腦皮層的細胞，大腦皮層是大腦中負責諸如記憶、感知、認知、思維和感官處理等真正重要事物的區(qū)域。

You can see a cross-section of one of the organoids below.

你可以看到下面某個有機物的橫截面。
Hundreds of these tiny brains were grown in culture over a period of 10 months, with testing to ensure the right genes for brain development were being expressed. They also continuously monitored the organs with electroencephalography (EEG).

在10個月的時間里，數(shù)百個這樣的小大腦在培養(yǎng)皿中生長，通過測試來確保大腦發(fā)育的正確基因得到表達。他們還用腦電圖(EEG)連續(xù)監(jiān)測這些器官。

By six months, Nature reports, the brainlets were showing very energetic brain activity - much more than any the team had noted before.

據(jù)《自然》雜志報道，到了6個月，這些腦小腦顯示出非?；钴S的大腦活動——這比研究小組之前所注意到的要多得多。

On analysis, the activity wasn't much like the organised, predictable brain activity of an adult. But it did bear a semblance to a different kind of brain activity. It had patterns in common with the chaotic bursts of synchronised brain activity seen in preterm infants.

據(jù)分析，這種活動與成年人有組織的、可預測的大腦活動不太相似。但它確實表現(xiàn)出一種不同的大腦活動。它與早產兒大腦同步活動的混亂爆發(fā)有著共同的模式。

"While network activity from organoids does not exhibit the full temporal complexity seen in adults, the pattern of alternating periods of quiescence and network-synchronised events is similar to electrophysiological signatures present in preterm human infant EEG," the researchers wrote in their paper.

研究人員在他們的論文中寫道:“雖然來自類器官的網絡活動，不像成年人那樣呈現(xiàn)出完全的時間復雜性，但靜息期和網絡同步事件交替出現(xiàn)的模式，與早產兒腦電圖中的電生理特征類似。”

It wasn't exactly the same. But a machine learning model trained on preterm EEG signatures was able to identify many features in common with a normal developmental timeline. Past 28 weeks, the organoids seemed to be on a similar developmental trajectory as a preterm baby of the same age.

這完全不一樣。但是，一個經過早產兒腦電圖特征訓練的機器學習模型，能夠識別出許多與正常發(fā)育時間表相同的特征。在過去的28周里，類器官似乎和同年齡的早產兒有著相似的發(fā)育軌跡。

The brain organoids are not quite like the parts of actual human brains - not only are they scaled down and simplified, the also don't have other brain regions to connect to. They were also engineered to be deficient in a proteinthat's essential for the normal function of neurons.

類腦器并不完全像人類大腦的各個部分——它們不僅被縮小和簡化了，而且也沒有其他大腦區(qū)域可以連接。他們還被設計成缺乏一種對神經元正常功能至關重要的蛋白質。

But they could represent a step towards a better understanding of brain development, since the brains of premature babies aren't exactly easy to come by, and adult brains are notoriously complicated.

但它們可能代表著朝著更好地理解大腦發(fā)育邁出的一步，因為早產兒的大腦并不容易獲得，而成人的大腦是出了名的復雜。

"While we do not claim functional equivalence between the organoids and a full neonatal cortex," the researchers wrote, "the current results represent the first step towards an in vitro model that captures some of the complex spatiotemporal oscillatory dynamics of the human brain."

研究人員寫道：“雖然我們不主張器官和完整的新生兒皮層之間的功能等效，但目前的研究結果代表了向體外模型邁出的第一步，該模型捕捉了人類大腦復雜的時空振蕩動力學。”

The researchers are going to continue to try to develop the brainlets further to see if they continue to mature.

研究人員將繼續(xù)嘗試進一步開發(fā)大腦，看看他們是否會繼續(xù)成熟。

But others are genuinely concerned at the proximity of developing consciousness in a tub of culture in a lab. So far, none of the brains show any signs of consciousness, but as the experiment continues, it could be a possibility.

但是有些人真正關心的是，在實驗室的培養(yǎng)盆中培養(yǎng)意識的接近性。到目前為止，沒有大腦顯示出任何意識的跡象，但是隨著實驗的繼續(xù)，這可能是一種可能性。

"The closer they get to the preterm infant, the more they should worry," neuroscientist Christof Koch of the Allen Institute for Brain Science in Seattle told Nature back in November 2018, when the research was presented at .

西雅圖艾倫腦科學研究所的神經學家克里斯托夫·科赫(Christof Koch)于2018年11月向《自然》雜志表示：“他們越接近早產兒，就越應該擔心。”

Given the careful engineering of the organoids to inhibit normal function, the researchers are not worried at this stage. However, if any start to show signs of consciousness, they will consider shutting the project down.

考慮到有機物對抑制正常功能的精心設計，研究人員在此階段并不擔心。然而，如果一旦開始表現(xiàn)出意識的跡象，他們會考慮關閉項目。

The research has been published in Cell Stem Cell.

這項研究發(fā)表在《細胞干細胞》雜志上。