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Biological Miracle – Wood Frog

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Re: Biological Miracle – Wood Frog

#91

Post by javajosh »

>Also, the wood frog's ability to withstand freezing may help researchers discover how human organs used for transplants could be frozen and thawed without damage. This would increase the allowable time between removing an organ from a donor and implanting it within the recipient, which could make many more transplants possible.

While certainly some good would come of this, imagine the unintented consequences of such an advancement, especially in a world with stark income inequality.

Re: Biological Miracle – Wood Frog

#92

Post by blue_pants »

plastic3169 wrote: post #82
PhasmaFelis wrote: post #72

Earlier quoted context omitted.

Interestingly, you can freeze a rat solid in liquid nitrogen--completely solid right through--and then thaw them out in a microwave and they actually survive. Well, many of them survive. For a while. Okay, it's not good for the rats but it's still crazy that it works.

Where can I read more about this? If this was a fact I think people would be way more excited about cryonics. Casually browsing wikipedia suggests that we are not there yet with the ability to thawn large animals or even organs.

From https://en.wikipedia.org/wiki/James_Lovelock

"In the mid-1950s, Lovelock experimented with the cryopreservation of rodents, determining that hamsters could be frozen and revived successfully.[14] Hamsters were frozen with 60% of the water in the brain crystallised into ice with no adverse effects recorded. Other organs were shown to be susceptible to damage.[15]"

And there's a Tom Scott's interview with James Lovelock:

https://www.youtube.com/watch?v=2tdiKTSdE9Y

Re: Biological Miracle – Wood Frog

#94

Post by abainbridge »

abound wrote: post #66

> Nobody yet understands what starts the wood frog’s heart after being frozen and inert for the entire northern winter. To me, that's the most fascinating part of the (already quite fascinating) story. Frog is frozen solid, there is no (to our knowledge) heartbeat or brain activity. It thaws and something happens that gets it going again. I have trouble imagining what that mechanism could even look like. Tiny portion…

I skimmed https://en.wikipedia.org/wiki/Sinoatrial_node#Function. Here's my guess at what is going on:

In humans (and I guess many animals), the thing that controls the heart beat is a structure in the heart called the Sinoatrial node. Each cell in the SA node has an ability to generate its own rhythmic electrical impulse. I imagine that when one of these cells thaws out in a Wood frog, it immediately starts producing its rhythmic pulse. It has to get in sync with the rest of the cells in the Sinoatrial node before the heart will beat correctly, so the cells have a mechanism to communicate their rhythm with their neighbours. I guess each cycle, each cell adjusts its phase a little towards the average phase of its neighbours and thus a consensus will be reached.

Re: Biological Miracle – Wood Frog

#95

Post by w10-1 »

For those thinking freezing could be an option... there's a fair bit more than just avoiding ice crystals.

Medical hypothermia in humans (which is just a few degrees colder) is bounded not really by not by time-cold but by restoring normal temperature too quickly. It turns out mitochondria generate a lot of free oxygen radicals when going hypoxic, and restoring oxygen quickly does the chemical damage that actually causes death - so they restore normal temps over a period of hours. I'd bet that's not the only metabolic cycle deranged by hypercooling.

Re: Biological Miracle – Wood Frog

#96

Post by metalman »

flir wrote: post #40
metalman wrote: post #5

cant even call that hibernation. There are other knock on advantages to bieng frozen solid, it would slow down and even kill a lot of infectious microbes.It may convey a certain life extension benifit. And threre is not much behavioral adaptation needed,frog gets chilly, snuggles under a leaf,freezes solid, gets defrosted 8 months later and wakes up hungry and horny, not bad.

> It may convey a certain life extension benefit. I think it would be more interesting if it doesn't affect lifespan. It would be a really counter-intuitive result (to me).

either way, or any info that could be gathered about life expectancy due to cryosuspension hibernation, is good, even a null result is data that plays into many conversations about longevity, space travel, temporary medical suspension to buy time. The fact of this type of biological process, moves the brackets quite a bit in how to think about many? all? other biological processes. Here is a little game....try and think about the world from a wood frogs perspective

Re: Biological Miracle – Wood Frog

#97

Post by agumonkey »

abound wrote: post #66

> Nobody yet understands what starts the wood frog’s heart after being frozen and inert for the entire northern winter. To me, that's the most fascinating part of the (already quite fascinating) story. Frog is frozen solid, there is no (to our knowledge) heartbeat or brain activity. It thaws and something happens that gets it going again. I have trouble imagining what that mechanism could even look like. Tiny portion…

Maybe the system relies on average heat randomness to bootstrap again ..

Re: Biological Miracle – Wood Frog

#98

Post by macrolime »

8n4vidtmkvmk wrote: post #85
dexwiz wrote: post #17

Wood frogs only live 3-5 years, so they probably only go through a max of 5 of these cycles. I wonder how much cellular damage they accumulate during these cycles that they can tolerate due to short lifespans. They also have ~10,000x less neurons than a mammal. Even if you had the biochemistry that was able to do this, how many cycles could a higher life form tolerate this, assuming it would even work? Complex life s…

I don't understand why we're not allowed to regrow limbs. What did that make room for in our DNA?

Some animals regenerate, some form scar tissue. It's thought that scar tissue is a cheaper and faster mechanism than regrowing limbs and has thus been selected in many cases.

Re: Biological Miracle – Wood Frog

#99

Post by lukan »

durkie wrote: post #62

A great book about how animals survive super cold winters is "Winter World" by Bernd Heinrich. Bernd is a super fascinating biologist who really dives deep in to things. At one point in the book I think he was talking about chipmunks surviving winter, and it goes really fun on the first principles. Something like: "chipmunks have a surface area of X m^2, and need to maintain an internal temperature of Y˚C. If the out…

"Well I found a dead one and shoved pine nuts in to its mouth until I couldn't fit anymore, and managed to get 17 in there."

That part is .. weird. What is the point except morbid humor?

Chipmunks have a food storage, so they don't store nuts in their mouth. They wake up, go to the food storage and eat and go back to sleep. They don't go outside to collect more nuts in -40°C. Maybe that was the point of that calculation, to show it would not be a good strategy, but there ain't much nuts in winter on trees left anyway.

(and the calculation above lacks insulation of the fur and their sleeping place)

Re: Biological Miracle – Wood Frog

#100

Post by mock-possum »

abainbridge wrote: post #94
abound wrote: post #66

> Nobody yet understands what starts the wood frog’s heart after being frozen and inert for the entire northern winter. To me, that's the most fascinating part of the (already quite fascinating) story. Frog is frozen solid, there is no (to our knowledge) heartbeat or brain activity. It thaws and something happens that gets it going again. I have trouble imagining what that mechanism could even look like. Tiny portion…

I skimmed https://en.wikipedia.org/wiki/Sinoatrial_node#Function . Here's my guess at what is going on: In humans (and I guess many animals), the thing that controls the heart beat is a structure in the heart called the Sinoatrial node. Each cell in the SA node has an ability to generate its own rhythmic electrical impulse. I imagine that when one of these cells thaws out in a Wood frog, it immediately starts produci…

Fireflies eventually manage to more or less sync up and they’re completely separate organisms - tiny cells with physical connections inside the body should be able to make it work.
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