每日英語跟讀 Ep.K337: How the Coronavirus Steals the Sense of Smell

Few of COVID-19’s peculiarities have piqued as much interest as anosmia, the abrupt loss of smell that has become a well-known hallmark of the disease. COVID patients lose this sense even without a stuffy nose; the loss can make food taste like cardboard and coffee smell noxious, occasionally persisting after other symptoms have resolved.

很少有COVID-19的特殊性像嗅覺喪失那樣引起人們的興趣，嗅覺喪失已成為該疾病的一個眾所周知的標誌。即使沒有鼻塞，COVID患者也會失去這種感覺;這種損失會使食物嘗起來像紙板和咖啡一樣有毒，偶爾會在其他癥狀消退後持續存在。

Scientists are now beginning to unravel the biological mechanisms, which have been something of a mystery: The neurons that detect odors lack the receptors that the coronavirus uses to enter cells, prompting a long debate about whether they can be infected at all.

科學家們現在開始解開生物學機制，這一直是一個謎：檢測氣味的神經元缺乏冠狀病毒用來進入細胞的受體，引發了關於它們是否可以被感染的長期爭論。

Insights gleaned from new research could shed new light on how the coronavirus might affect other types of brain cells, leading to conditions like “brain fog,” and possibly help explain the biological mechanisms behind long COVID — symptoms that linger for weeks or months after the initial infection.

從新研究中收集的見解可以揭示冠狀病毒如何影響其他類型的腦細胞，導致"腦霧"等疾病，並可能有助於解釋長期COVID背後的生物學機制 - 這些癥狀在最初感染後持續數周或數月。

The new work, along with earlier studies, settles the debate over whether the coronavirus infects the nerve cells that detect odors: It does not. But the virus does attack other supporting cells that line the nasal cavity, the researchers found.

這項新工作以及早期的研究解決了關於冠狀病毒是否會感染檢測氣味的神經細胞的爭論：它沒有。但研究人員發現，這種病毒確實會攻擊鼻腔內的其他支持細胞。

The infected cells shed virus and die, while immune cells flood the region to fight the virus. The subsequent inflammation wreaks havoc on smell receptors, proteins on the surface of the nerve cells in the nose that detect and transmit information about odors.

受感染的細胞脫落並死亡，而免疫細胞則淹沒該區域以對抗病毒。隨後的炎症對嗅覺受體造成嚴重破壞，嗅覺受體是鼻子神經細胞表面的蛋白質，可以檢測和傳遞有關氣味的資訊。

The process alters the sophisticated organization of genes in those neurons, essentially short-circuiting them, the researchers reported.

研究人員報告說，這個過程改變了這些神經元中基因的複雜組織，基本上使它們短路。

Their paper significantly advances the understanding of how cells critical to the sense of smell are affected by the virus, despite the fact that they are not directly infected, said Dr. Sandeep Robert Datta, an associate professor of neurobiology at Harvard Medical School, who was not involved in the study.

他們的論文顯著推進了對嗅覺至關重要的細胞如何受到病毒影響的理解，儘管它們沒有直接感染，哈佛醫學院神經生物學副教授Sandeep Robert Datta博士說，他沒有參與這項研究。

“It’s clear that indirectly, if you affect the support cells in the nose, lots of bad things happen,” Datta said. “The inflammation in the adjacent cells triggers changes in the sensory neurons that prevent them from working properly.”

"很明顯，間接地，如果你影響鼻子中的支持細胞，就會發生很多不好的事情，"達塔說。 "相鄰細胞中的炎症觸發了感覺神經元的變化，使它們無法正常工作。"

Indeed, many complications of COVID appear to be caused by the immune system’s friendly fire as it responds to infection by flooding the bloodstream with inflammatory proteins called cytokines.

事實上，COVID的許多併發症似乎是由免疫系統的友好之火引起的，因為它通過用稱為細胞因數的炎症蛋白淹沒血液來應對感染。Source article: https://udn.com/news/story/6904/6158661

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每日英語跟讀 Ep.K338: 新冠病毒如何偷走嗅覺

通勤學英語 15Mins Today