59: Flatworms

Can Flatworms remember how to find food after re-growing their heads? Science rolled up its sleeves and found out.

Flatworms Transcript:

Welcome to Brain Junk, I’m Trace Kerr, and I’m Amy Barton, and this is a Brain Storm.

AB: This is a Brain Storm about the beheading of flatworms. I’m just going to lead with that and tell you right away where this is going.

TK: Oh no!

AB: I know. The good news is flatworms are among the types of worms, I’m not sure if it’s all worms that can grow their heads back, or if there’s categories where it’s curtains if you lose your head. Flatworms, good news, flatworm fans! Flatworms grow their heads back. Joseph Stromburge of Smithsonian Magazine has brought us new and exciting information about how the memory works with flatworms, and it’s something that scientists have kind of hypothesized about since the 1950’s. Scientists from Tufts University, Tal Shomrat and Michael Levin, have new experiments that show that beheaded flatworms can actually retain trained behaviors  after their brains have regenerated. So worm loses it’s head, it regrows after about a couple weeks, and they show evidence that they know stuff they used to know that they shouldn’t. And this is something that’s been around since the 50’s. Scientists were doing experiments and were like ‘You guys!’ regarding memory RNA and then the scientific community looked at it and were like, we feel like there’s some bias, we don’t think memory RNA is a thing, and so it was shelved, clearly, for like 60 years.

TK: I have so many questions. So, there’s only one brain? It’s not like there’s multiple little brains, like down some nervous system, and so the head is gone, and then like how do they eat...?

AB: One brain. And presumably they’re sort of hibernating and healing.

TK: How are we, how, huh?

AB My scientific research is EXTREMELY shallow, and includes only the parts I’m interested in.

TK: What do they do? That’s what I want to know.

AB:   So right now, I’m going to tell you about how the experimentation works. There’s petri dishes with food, there’s some worms that live in a completely flat bottomed dish that have food, and some that live in a rough surfaced petri dish. And so they train the flatworms. The flat surface for the ones is where the food is, the rough surface, for the others, is where the food lives for the other worms. So they kind of know, ‘if I go to this rough surface there’s probably going to be food there’. And then the flat ones know.

TK: Ah.

AB: And so then they create an environment where it’s kind of hostile because they don’t like light, so they illuminate one section and they put the food in the illuminated area. So it’s aversive to the flatworm to go there, but they also know there’s food. So they trained them. Rough surface means food so even if there was a light, which they didn’t like, they’d go there. Then they chopped their heads off.

TK: Oh!

AB: Two weeks though, everybody, it’s just two weeks and they’re back. And so then, they put them in that same circumstance again and the ones that associated rough surface would go right back to that illuminated surface again, without that period of training them first-rough surface needs food-and then they’d bypass that whole learning process.

TK: That’s stunning! How, so what is their hypothesis? What do they think is happening?
AB: Well, magic. Probably the internet. No, they actually do have some hypothesis that maybe the nervous system does have some part of that process. They’re very hazy. Even this article was very “Amy-Like” in the way they phrased things. So this is a very new, they clearly can say it’s probably not memory RNA, that’s probably not a thing, but 1950’s scientists definitely observed a real thing, even if their experiments weren’t that great and had some bias. Because they hypothesized in the original experiments, they were grinding up and feeding them to the new flatworms and saying ‘look, they have the memories the old guys had!’ and the scientific community said no.

TK: I saw that in a Fringe episode!

AB: Yeah! Totally, yes. So good. Ahhh, Fringe.

TK: So any science, sufficiently advanced, will look like magic. So these worms,

AB: Clearly. It doesn’t take long for it to appear like magic for me. But I love that. I think it’s completely fascinating.

TK: Wow. I hope nobody cuts off my head to see if I can remember anything, cause it’s not going to happen.

AB: Agreed. There’s nothing left.

TK: So if you want to hear more, we’re on Facebook and Instagram as BrainJunkPodcast, and you can find us on Twitter as @MyBrainJunk. Amy and I will catch you next time with more of everything you never knew you wanted to know, and I guarantee, you will not be bored.

AB: For sure.