Decapitated Worms Regrow Heads, Keep Old Memories – National Geographic Blog

Authored by blog.nationalgeographic.org and submitted by dandelion411

In French Revolution-style, researchers decapitated flatworms—then did something that would give even Madam Defarge the creeps.

The scientists let the worms’ heads grow back and found that their memories returned along with the new noggins, according to a new study in the Journal of Experimental Biology.

Michael Levin and Tal Shomrat, biologists at Tufts University, have been studying how animals store and process information, whether it’s memories in the brain or the blueprint for developing organs in the body.

The team turned to flatworms because, despite their relative simplicity, they have many of the same organs and body organization as people: a brain and nervous system, bilateral symmetry, and even some of the same behaviors.

Flatworms “also have many of the same neurotransmitters as we do, and have been shown in older studies to remember complex tasks,” Levin said. (Read more about memory in National Geographic magazine.)

Yet unlike people, these worms have a remarkable ability to regenerate organs and body parts, including their brains—making them perfect research subjects.

Planarian flatworms are a hugely diverse array of small non-parasitic worms found in both freshwater and saltwater environments.

They have primitive eyes that can detect light, which they generally avoid—being in light makes them more obvious to predators.

To train the worms that lighted areas were safe and contained food, the researchers used a computerized device to continually track the worms’ behavior, providing rewards when a worm ventured into the bright spots and punishments when it remained in the dark.

“We used this device to get worms used to a dish with a peculiar laser-etched surface. When they remember this surface, they will rapidly approach a piece of liver to eat it, as opposed to spending much time circling around the dish to get the lay of the land,” Levin said.

After the team verified that the worms had memorized where to find food, they chopped off the worms’ heads and let them regrow, which took two weeks.

Then the team showed the worms with the regrown heads where to find food, essentially a refresher course of their light training before decapitation.

Subsequent experiments showed that the worms remembered where the light spot was, that it was safe, and that food could be found there. The worms’ memories were just as accurate as those worms who had never lost their heads. (Test your memory with a National Geographic game.)

The obvious question remains: How can a worm remember things after losing its head?

“We have no idea,” Levin admitted. “What we do know is that memory can be stored outside the brain—presumably in other body cells—so that [memories] can get imprinted onto the new brain as it regenerates.”

Researchers have long confined their investigations of memory and learning to the brain, Levin said, but these results may encourage them to look elsewhere. (Read about a tadpole that can see through an eye implanted on its tail.)

“We’ve established a new model system in which our future work will be able to figure out how memories get encoded and decoded to and from living tissues.”

And given that we can’t regrow their heads, it’s unlikely that decapitation will ever become a serious memory aid for frantic students before exams.

gmcl86 on June 1st, 2018 at 12:16 UTC »

After the team verified that the worms had memorized where to find food, they chopped off the worms’ heads and let them regrow, which took two weeks.

Then the team showed the worms with the regrown heads where to find food, essentially a refresher course of their light training before decapitation.

Subsequent experiments showed that the worms remembered where the light spot was, that it was safe, and that food could be found there. The worms’ memories were just as accurate as those worms who had never lost their heads.

w00tboodle on June 1st, 2018 at 12:03 UTC »

Including the memory of it getting its head cut off?

That's going to be one flatworm out for revenge. The scientist who discovered this better sleep with one eye open.

fakenewsoftheworld on June 1st, 2018 at 11:38 UTC »

fun fact this is because the memory is stored in the balls