微生物群落有工作記憶，可以把它們變成活的計(jì)算機(jī)

微生物群落有工作記憶，可以把它們變成活的計(jì)算機(jī)

Collections of bacteria known as biofilms can store memories of exposure to light, providing intriguing parallels to the way neurons process memories in our brains. This doesn't mean you need to be nice to bacteria lest they harbor a grudge, but it may prove useful for neuroscience research and making biological computers.

被稱為生物膜的細(xì)菌群可以儲(chǔ)存暴露在光下的記憶，這與我們大腦中神經(jīng)元處理記憶的方式有有趣的相似之處。這并不意味著你必須善待細(xì)菌，以免它們懷恨在心，但它可能對(duì)神經(jīng)科學(xué)研究和制造生物計(jì)算機(jī)有用。

Recent discoveries by Professor Gürol Süel of the University of California San Diego have helped promote renewed respect for bacteria, demonstrating they can communicate with each other in colonies using ion channels and even support each to share resources. Süel and others have also demonstrated bacteria can remember certain events, changing their response to circumstances based on what they have experienced previously.

加州大學(xué)圣地亞哥分校的Gurol Suel教授最近的發(fā)現(xiàn)幫助促進(jìn)了對(duì)細(xì)菌的重新尊重，證明細(xì)菌可以通過離子通道在群體中相互交流，甚至支持彼此共享資源。Suel和其他人也證明了細(xì)菌可以記住某些事件，根據(jù)它們之前的經(jīng)歷改變它們對(duì)環(huán)境的反應(yīng)。

Süel brings these two discoveries together in Cell Systems. Blue light has been found to alter the flux through cells' ion channels, so Süel's team spread Bacillus subtilis on a growth medium and illuminated them for five seconds with a fluorescent lamp. Using a mask of the University's logo, some of the bacteria were protected from the light, while others were fully exposed. Even hours later, the responses of the bacteria varied depending on whether they were shaded or not, with the exposed bacteria having more potential to transport potassium through their membranes.

Suel在細(xì)胞系統(tǒng)中把這兩個(gè)發(fā)現(xiàn)結(jié)合在一起。人們發(fā)現(xiàn)藍(lán)光會(huì)改變細(xì)胞離子通道的通量，所以Suel的研究小組將枯草芽孢桿菌(Bacillus subtilis)傳播到生長(zhǎng)培養(yǎng)基上，用熒光燈照射它們五秒鐘。利用該大學(xué)標(biāo)志的面具，一些細(xì)菌被保護(hù)起來不受光照，而另一些則完全暴露在陽(yáng)光下。即使在數(shù)小時(shí)后，細(xì)菌的反應(yīng)也會(huì)根據(jù)它們是否被遮蔽而有所不同，暴露在陽(yáng)光下的細(xì)菌更有可能通過細(xì)胞膜運(yùn)輸鉀。

Stephen Luntz

"When we perturbed these bacteria with light they remembered and responded differently from that point on," Süel said in a statement.

Suel在一份聲明中說:“當(dāng)我們用光線干擾這些細(xì)菌時(shí)，它們的記憶和反應(yīng)從那時(shí)起就不同了。”

When potassium availability was cycled on and off, the light-exposed bacteria produced the exact opposite response to those that had been shaded, closing their potassium channels when their counterparts were opening them. Feeding the bacteria glutamine restored them to their usual state. The researchers hope to put this to use, turning bacteria into a model for neurons.

當(dāng)鉀的有效性循環(huán)時(shí)，暴露在陽(yáng)光下的細(xì)菌產(chǎn)生的反應(yīng)與那些被遮蔭的細(xì)菌完全相反，當(dāng)它們的對(duì)手打開鉀離子通道時(shí)，它們卻關(guān)閉了鉀離子通道。給細(xì)菌喂食谷氨酰胺使它們恢復(fù)到正常狀態(tài)。研究人員希望利用這一點(diǎn)，把細(xì)菌變成神經(jīng)元的模型。

“For the first time we can directly visualize which cells have the memory,” Süel added. “That's something we can't visualize in the human brain."

“我們第一次可以直接看到哪些細(xì)胞有記憶，”Suel補(bǔ)充道。“這是我們無法在人腦中想象出來的東西。”

With suitable masks, bacteria could be turned into a circuit board, with some light-primed and others not, turning bacterial communities into a sort of computer. The team also found longer light exposures produced greater changes to membrane potential, suggesting outcomes could be more nuanced than simply whether a bacteria was primed or not. If varying intensity or wavelength of light produce different sorts of priming, then even more sophisticated devices may be possible.

有了合適的掩模，細(xì)菌可以變成電路板，有些可以發(fā)光，有些則不能，把細(xì)菌群落變成某種電腦。研究小組還發(fā)現(xiàn)，長(zhǎng)時(shí)間的光照會(huì)對(duì)細(xì)胞膜電位產(chǎn)生更大的變化，這表明結(jié)果可能比簡(jiǎn)單地判斷細(xì)菌是否受到了刺激更微妙。如果不同強(qiáng)度或波長(zhǎng)的光產(chǎn)生不同種類的啟動(dòng)，那么更復(fù)雜的設(shè)備可能成為可能。

"Bacteria are the dominant form of life on this planet," Süel said. "Being able to write memory into a bacterial system and do it in a complex way is one of the first requirements for being able to do computations using bacterial communities."

“細(xì)菌是這個(gè)星球上的主要生命形式，”Suel說。“能夠?qū)?nèi)存寫入細(xì)菌系統(tǒng)并以一種復(fù)雜的方式進(jìn)行操作，是使用細(xì)菌群落進(jìn)行計(jì)算的首要要求之一。”