"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)

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.

a chemical reaction that is sensitive to temperature.

Maybe something like a bit flip but for neurons happens in the frog's brain from the sun's radiation or something.

Or the elasticity of the heart and muscles.

my poor knowledge of biology says it's a deeply unsatisfying "heart beats when enough of the body has thawed for it to beat."

If the heart depends on the brain at all in frogs.

What puzzles me is... it is not just the heart but the entire circulatory system.

Maybe it is that thawing happens in reverse with the extremities, then the rest of the system thawing, with the heart being last. Would be a biological advantage in this case for the heart to be centrally located.

Most likely it isnt that the heart stops or starts in response to freezing. The heartbeat signal probably runs 24/7 unless inhibited by freezing. So as soon as it thaws, the signaling bit resumes its pulsing and the rest of the heart begins to beats as it also thaws. The order in which organs thaw would be regulated by sugar levels. Remember too that at this scale frogs can absorb much of their needed O2 through their skin. A steady heartbeat isn't as essential as it is with us.

Yeah, I was wondering about that too, but on the other hand, there are possibilities:

You don't need a brain to execute "programmed behavior" in a body, the cells have enough "compute" in the regulatory networks of their DNA, RNA and proteins to do that on their own (and in fact do it all the time as part if their normal functioning. That's what "metabolism" means.)

Another question would be where the cells take the energy to execute that program if blood circulation has halted and there is no oxygen. But then on the other hand, at that point they are filled to the brim with glucose. So I wonder if this isn't just to prevent freezing but also as an energy reserve for the "restart".

(Sorry for the bad programming analogies in this post, please don't take them too literally)

I'm thinking that there has to be something that is still keeping the rhythm going, maybe an extremely faint signal, all throughout that dormant period

The frog is not frozen solid.

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

"frogs don’t freeze once and stay frozen. Instead, they spend a week or two freezing at night and thawing during the day until the temperatures drop permanently below freezing"

https://shakerlakes.org/frozen-frogs/

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

- Artificial experiment [1]: no longer than 3 months (but see disclaimer)

- New study [2]: 7 months (with 100% survival rate)

So further study seems to be needed.

[1] https://journals.biologists.com/jeb/article/216/18/3461/1160...

[2] https://journals.biologists.com/jeb/article/217/12/2193/1211...

It's a bit of a fantasy that we might find a perfectly well preserved dinosaur in a glacier somewhere.

Reading about them, it seems they migrate in winter (like half a mile uphill), but the adults always return to the same breeding pond in spring, so that information is stored somewhere.

I would assume that just as a computer’s storage remains intact after a restart, these frogs’ brains have internal structure, synaptic connections etc that are preserved after a freeze/thaw cycle.

Hibernate and resume.

Couldn't you inject liposomal ATP into the bloodstream before the cooling process? Then mitochondria could simply be turned off. (I don't mean simple when I use the word simply)

That's a word I don't know (and neither do you): brumation, invented in 1965.

https://en.wiktionary.org/wiki/brumation

The verb ought to be brumate. But I guess the desire to pull it into line with hibernation is strong, this happens with lots of words. (Or was the influence from "rumination"?)

Our tortoise, even though he's in a very comfortable climate controlled indoor pen, tries to dig a hole every year to do the same.

He's not very smart but he tries hard.

From the linked video: timelapse of the thawing process: https://youtu.be/pLPeehsXAr4?t=176

They also have a wiki, but not many photos. One photo is from Quebec.

The wiki also mentions that urea is produced, in addition to glucose, and both act as cryoprotectants.

https://en.m.wikipedia.org/wiki/Wood_frog

Looks like a normal (frozen) frog to me

> it would slow down and even kill a lot of infectious microbes

I wouldn't count on it killing them. The cryoprotectants in the frog's body don't discriminate; they'll protect foreign bacteria just as well as the frog's cells.

> 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).

I think there are threads in Michael Levin's work that suggest membrane voltage potential may be able to be 'encoded' to microtubule structures and converted back into voltage potentials later. I don't think it's firmly established or understood yet but seems like a promising area for research!

Perhaps because ice forms outside cells, freezing ions in place. Even if there was a very small area around ion channels that was liquid that equalized all ion concentrations with the cell, when the extra cellular fluid thaws the original concentrations would be pretty much restored

I'm not even joking about this -- since frog legs are a thing people eat (taste kinda like chicken), I'm now incredibly curious what this would taste like if you "caught" these in their frozen state and cooked them.

Are we taking syrupy sweet meat? Or just a hint of it?

Oh god. This made me wonder, what is wood, anyway? And I've just come away much more confused.

Bamboo is a grass and doesn't come from a tree. Palm wood comes from palm trees, except palm tree trunks are apparently a totally different type of structure than other tree trunks, sounds closer to Papyrus. No growth rings, a fiber type structure. Is Papyrus wood?

Any plant matter above a certain density? I don't think that's it. Corn stalks aren't wood.

Man, I don't know. I am certain that it must be plant matter though, so yes, a wooden frog would be a biological miracle.

Of the frogs? Sure!

Only guaranteed to last for four or five months, so probably would be a very short interstellar travel

Be careful though, if you send an all female human crew enhanced by frog genes, some of them might change sex on the way.

No. Article says they have 1000x sugar in their blood. When we get to 10x we tend to die.

A live frozen frog has ice around it's cells. Inside the cells remains liquid because of extra glucose acting as anti-freeze.

A dead frozen frog will be frozen completely, with all the cells having ruptured walls from their insides freezing.

We use glucose to generate energy that we burn metabolically to keep themselves warm all the time. I assume that the frogs can do it also partially.

this seems implausible to me based on how heat generally transfers...

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The One who created it with care and compassion has arranged its pain. Perhaps it is like us waking up from sleep."

here's an illustration of one: https://image.non.io/e9078e7d-5eb4-4787-9fe2-d7068d01a4df.we...

But the article explains perfectly how they look like. White eyes, glucose filled cells, frozen solid as a rock. Bang it against a table, it's definitely frozen. Throw it back underneath those leaves.

Like the Tree Octopus?

Why does it only count if the cells themselves freeze? Also, am I still allowed to play freeze tag, or do we need to rename that?

Can't tell if joking...