You’ve heard the old adage  that time heals all wounds.

But when time’s not on your side, there’s a lesser known saying  that deer heal wounds much faster. Yeah, no that one’s… that one’s not real.

But the science of deer healing wounds is. And to get to that point in medicine,  scientists had to first put antlers on mice. Stay with me.

It’s all gonna  make sense in a minute. [♪ INTRO] Deer are so underrated. They’re the only mammals that can completely regenerate an  entire organ from scratch. Like, we can regenerate a  good chunk of our livers, but that’s nothing compared to what deer can do.

Every spring, deer shed an  entire organ from their heads. And by the end of the summer, they’re  growning it back like it was nothing! Antlers are the overlooked organs that hold the key to fast healing  and regrowth for all mammals.

They are the fastest growing bone on any animal! And they grow so fast because  of special antler stem cells. In 2023, a team of researchers  in China and Denmark published their investigation into these  speedy cells in the journal “Science.” They monitored the kinds  of cells that were present in the antler nubs during each stage of growth.

And they found a few transition  points throughout the process. The first wave of cells show up 10  days before the old antlers fall off. These cells stand by and await  instructions to start building new bone.

Then the old antlers fall off, marking day 0. The cells that dominate at  this point are more involved in making fibrous connective tissue  that attaches to the base. Five days later, blood vessel and  immune cells come onto the scene, making sure that the antlers  get all of the nutrients and protection they need to grow.

And, finally, the key ingredient  is introduced: antler stem cells. These are the cells that turn into the  cartilage and bone that make up antlers. Over the next three months,  these stem cells move so they are always at the outer tip of the growing antler.

And while they’re moving out,  the deeper layers that they leave behind are replaced with  more sturdy bone material. So deer are able to completely  replace a lost organ in three months! We… I… I don’t… like we think this is normal.

We see it all the time so we think it’s normal, but there is no other mammal that can just make a new organ appear out of nowhere. And there is no other animal that  grows something like that so fast. Which got the laboratory dwellers thinking.

If we can take these incredible antler  stem cells and put them in another mammal, maybe deer don’t have to be the  only ones with this super power. Then maybe we could grow new bones when we damage our old ones, and do it in record time! But first, scientists needed  to see if antler stem cells could function when they’re not in a deer.

Because if it’s something else about the  deer that makes these cells so effective, then putting them in another  mammal would do diddly squat. So they did the first thing that you learn in “How to be a scientist 101” and got some mice. Mice are mammals, deer are  mammals, and we’re mammals.

What could go wrong? The scientists transplanted  those antler cells into mice, and sure enough, the mice  started growing small antlers. And yes, they are just as bizarre as you  would expect mice with antlers to look.

But, I mean, really. Antlers are not on the approved  list of body parts for mice, so it might have been more concerning  if they looked like they belonged there. The researchers essentially made  a kind of real life jackalope.

But the big news here was that we learned we could in fact get these magic deer cells to  do what they do in other mammals, too. So once that was established,  it was time to figure out how to use these cells to replace  broken bones with not broken bones. After all, what is growing antlers  if not adding bone to your body?

So when the same cells are  put on broken femur bones, they don’t, like, make you a leg antler. They fill the gap in the bone! Or at least, they did for a bunch  of rabbits in that same study.

And these incredible antler cells  don’t stop at repairing broken bones! Another study out of China  applied antler stem cells to rats that were missing chunks of their skin,  like you would if you fell down a hill and ended up with a big gash on your arm. And, yes, rats can heal their own skin.

But when the antler stem cells were  helping out, they did it 9 days faster. Which makes sense because part of the  appeal of studying antler stem cells in the first place is just  how incredibly fast they work. These researchers think that the speed  comes from a higher concentration of growth factors in antler stem cells than what other mammals have in their repair cells.

So when the rat cells are  exposed to antler stem cells, they start multiplying like never before. This means that antler stem  cells can help other mammals grow and repair their bodies faster  than they would on their own. Now none of this has been tested  in humans yet because the research is so new that we haven’t fully debated  the ethics of putting these cells into us.

But antler stem cells are similar to  the cells we use to grow our own bones. One day, we may be able to  use that to our advantage. So if anyone’s got a bone to pick with  deer, they should pick the antler.

It might come in handy if they ever get injured. You know what else comes in handy? Our patrons.

People who give money to Scishow on  Patreon make this channel possible. If you are a Patron, thank you very  much; we could not do this without you. If you would like to become a patron, there’s probably a link in the description  I’d say, or you can just google it.

Look, we’re not making this hard, you can do it. You don't have to. But the people  who do it, they're the real MVP's.

You know what you know what I’m saying? That’s what I’m saying… [♪ OUTRO]