cover of episode Real-Life Human Hibernation

Real-Life Human Hibernation

2024/11/28
logo of podcast Discover Daily by Perplexity

Discover Daily by Perplexity

People
A
Alex
通过在《Mac Geek Gab》播客中分享有用的技术提示,特别是关于Apple产品的版本控制。
Topics
Alex: 本期节目探讨了科学家在实现人类冬眠方面取得的进展。哈佛医学院的研究人员在老鼠的下丘脑中发现了控制类似冬眠状态的特定神经元,这为理解大脑如何启动和维持低生理活动状态提供了关键的切入点。这项发现为开发可控冬眠技术铺平了道路。动物冬眠时,心跳和呼吸会显著减慢,体温会降至接近冰点。例如,北极地松鼠能够在土壤温度降至冰点以下时主动调节体温,维持在低至-2.9摄氏度,同时防止组织损伤。黑熊则能够将其新陈代谢抑制到正常水平的25%,同时保持相对较高的体温。冬眠具有神经保护特性,动物在蛰伏期间可以清除大脑中有害的蛋白质缠结,这与阿尔茨海默病和帕金森病患者体内积聚的蛋白质相似。冷休克反应会激活一种名为RBM3的关键蛋白,有助于保护神经元并防止突触消除。一些医院已经开始使用改良的冷却技术将患者置于类似蛰伏的状态,以保护组织。冬眠会造成睡眠不足,动物在从蛰伏状态苏醒后需要大量的深度睡眠。目前,关于冬眠的研究正在快速发展,但要实现人类冬眠,仍面临诸多挑战,例如人体缺乏天然的冬眠触发机制和保护机制,容易形成危险的血凝块,冬眠期间免疫功能受损也是一个重大风险。尽管如此,从哈佛发现控制蛰伏的神经元到NASA计划的微重力实验,多方面研究的进展使我们越来越接近在太空探索和医学中实际应用人类冬眠。

Deep Dive

Shownotes Transcript

Translations:
中文

Welcome to Discover Daily by Perplexity, an AI-generated show on tech, science and culture. I'm Alex. Today we're exploring how scientists are getting closer to achieving what was once purely science fiction, human hibernation. Scientists at Harvard Medical School have identified specific neurons in the hypothalamus that control hibernation-like states in mice.

This discovery provides the first clear entry point for understanding how the brain initiates and maintains torpus states, a state of decreased physiological activity marked by reduced body temperature and metabolic rate.

The Harvard team's ability to selectively activate these neurons and maintain torpor for extended periods represents a crucial step toward developing controlled hibernation techniques. Through testing 226 different regions of the hypothalamus across 54 animals and analyzing nearly 50,000 individual cells, they've created a detailed map of the neural circuits involved in this complex biological process.

When animals hibernate, their bodies undergo remarkable changes. Their heart rates plummet. Chipmunks go from 350 to 10 beats per minute. Their breathing slows dramatically and body temperature can drop to near freezing levels.

Arctic ground squirrels demonstrate particularly impressive adaptations, actively thermoregulating when soil temperatures drop below freezing to maintain body temperatures as low as -2.9 degrees Celsius while preventing tissue damage. The process isn't simply about getting cold.

Black bears demonstrate a fascinating ability to suppress their metabolism to 25% of normal rates while maintaining relatively high body temperatures between. This metabolic suppression can persist even after hibernation ends, with bears maintaining reduced metabolic rates for up to three weeks after emerging from their dens.

Medical researchers are particularly interested in hibernation's neuroprotective properties. During torpor, animals can clear harmful protein tangles from their brains, some of the same proteins that accumulate in Alzheimer's and Parkinson's patients.

Even more remarkable, scientists have discovered that the cold shock response activates a crucial protein called RBM3, which helps preserve neurons and prevents synapse elimination in the hippocampus. When researchers increased RBM3 levels through gene therapy, they observed significant protection against neurodegeneration.

Some hospitals are already using modified cooling techniques to keep patients in torpor-like states for up to 14 days. This approach helps protect tissues after stroke and during cardiac surgery. And here's something unexpected: hibernation actually creates a sleep-deprived state.

Animals need significant deep sleep when emerging from torpor, with their brains showing complete recovery of neural microstructure and increased spine density after hibernation, indicating enhanced synaptic communication potential. The research on hibernation is expanding rapidly.

The University of Alaska has launched a nearly $12 million research program to study the effect on metabolism and investigate arctic ground squirrels. A Yale University lab is focusing on understanding the molecular basis of hibernation, while the Arctic University of Norway research lab is studying the brain's role during torpor arousal. But several challenges remain before human hibernation becomes reality.

our bodies lack natural hibernation triggers and protective mechanisms. Unlike bears, which can regulate blood platelet production during hibernation, humans are susceptible to developing dangerous blood clots even after brief periods of immobility. The suppressed immune function during hibernation poses another significant risk, with research showing up to 90% reduction in circulating white blood cells during torpor states.

As research advances on multiple fronts, from Harvard's discovery of torpor-controlling neurons to NASA's planned microgravity experiments, we're moving closer to practical applications of human hibernation in both space exploration and medicine. These converging studies bring us nearer to achieving controlled human torpor states that could transform long-duration spaceflight and revolutionize treatments for neurological conditions.

That's it for today. Thanks for tuning in, and don't forget to subscribe on your favorite platform. For more info on anything we covered today, check out the links in our episode description. And don't forget, you can now access Perplexity's AI-powered knowledge base on the go with the mobile app, available for both Android and iOS. We also just released the Perplexity desktop app for macOS.

In other Perplexity news, we're thrilled to share that Perplexity just launched an exciting new AI-powered shopping experience. The platform now offers one-click checkout with Buy with Pro, free shipping for Pro users, and a cool new Snap to Shop feature that lets you search for products just by taking a photo. We'll be back with more stories that matter. Until then, stay curious.