How to Freeze and Revive?

You hear about rich people freezing their bodies to be revived over hundreds of years, when a cure for their disease will be found or eventually, even the elixir of immortality.

Of course, these idiots are money milking machines for companies who know how to sell illusions.

But the one that could help turn this utopia into reality one day is the prince frog.

In temperate and polar zones, most animals, like birds and bats, migrate to warmer climate zones during the winter, while others retreat to deep burrows, the bottom of the lakes or caves where, even if the temperatures are few degrees over zero, never drop under the freezing point.

Others pass the winter as eggs, resistant to cold.

But wood frogs have a special quality: they winter under the leaves layer, where they actually freeze and thaw with their surroundings and can experience these variations as many times as they occur during the winter.

"They undergo freeze-thaw cycles all the time," said Kenneth Storey, a professor of biochemistry at Carleton University in Ottawa, Canada.

"In nature the frogs consistently go through freeze-thaw cycles. We have false springs here all the time where it gets really warm and all the snow melts and then suddenly-bam-the wind comes from the north and it's back down to minus 10, minus 15 [degrees Celsius], and they're fine," he said.

"So in nature and in the lab they have to do it, and they do."

Storey is interested in the molecular processes permitting wood frogs to freeze and thaw, a knowledge that would be extremely important in the technique of human organ transplants.

Currently, a donated organ can be used within hours before it becomes too damaged and freezing it is not an option, as it would kill the cells.

But a wood frog is able to freeze, becoming hard and crunchy (photo below).

"When you drop it, it goes 'clink,'" Storey said.

Particular blood proteins, named nucleating proteins, make the water in the blood freeze first but this ice also pulls out most of the water from the frog's cells.

Meanwhile, the frog's liver generates large quantities of glucose which amount into cells and prop them up; the glucose has the property of retaining water, impeding too much loss of it, which would kill the frog.

"Inside the cells there's no ice. It's just really, really, really dehydrated, all shrunk down osmotically and full of massive amounts of sugar," explained Storey.

Humans and most animal species lack the nucleating proteins, thus, when their skin freezes, the cells die by dehydration.

"Even if you take the ice away, it's way too late. All the cells are broken because you haven't made all that glucose," said Storey.

But the frogs can pass the winter in this stage of suspended animation, without any activity, like beating heart or brain activity.

When temperatures rise over freezing point, the frogs thaw: water slowly gets back into the cells, blood restarts flowing, and the frog gets back to life.

"In the lab, ice thaws in about 20 minutes and the heart takes another 20 or 30 minutes to start. Once the heart starts, it pumps the blood around the animal and the animal starts to revive, then it starts to gulp, then it starts to breathe, then it starts to hop away. So it takes a little while to reactivate after you've been frozen down," said Storey.

"The wood frogs can go through this cycle again and again. When spring finally arrives and decides to stay, the frogs hop around unharmed," he said.

Storey is more concerned about how frogs could cope with the recent warming.

"Freezing helps drop their metabolism and helps them survive over the long winter months when there's no food," he said.

"But our frogs would be fine if there was food out there, if the insects came out early and there was less winter."