This Flatworm Remembers Things After You Cut Off Its Brain

Summary

This video explores the fascinating regenerative abilities of planarians, flatworms known for their capacity to regrow lost body parts, including their brains. Even after decapitation, these creatures retain memories, raising questions about how and where memories are stored. Researchers have trained planarians to overcome their light aversion for food, showing they remember this even after head regeneration. This phenomenon suggests memory storage might occur outside the brain, challenging current understanding. The episode also highlights CuriosityStream, offering nature documentaries and other educational content for subscribers.

Takeaways

• 🪱 Planarians are flatworms known for their incredible regenerative abilities; they can regrow their tail or even form two whole worms when cut in half.
• 🧠 Even after losing their brain, planarians can still retain memories from before decapitation, which is unusual for most organisms.
• 🔬 Planarian brains, though simple, have two lobes and specialized regions, making them useful for studying brain evolution and memory.
• 🐛 Planarians can be trained to perform unnatural behaviors, and researchers can test if they retain memory under different conditions.
• 🍖 These flatworms dislike light and change but will overcome light aversion for food, like liver, especially after being familiarized with a new environment.
• 🗓️ Studies show that planarians can retain memories for at least 14 days after training, even when decapitated.
• 🤯 Despite losing their brains, trained flatworms show memory retention after regenerating their heads, although the memory is not fully intact.
• 💡 Scientists are intrigued by the idea that some memories may be stored in neurons outside the brain, challenging traditional views on memory.
• 🔍 This phenomenon could lead to important breakthroughs in understanding brain function and developing treatments for memory-related conditions.
• 🎥 The episode promotes CuriosityStream, a platform offering documentaries like 'The Year of the Hedgehog,' which explores quirky animals and ecosystems.

Q & A

What are planarians primarily known for?

Planarians are primarily known for their incredible regenerative abilities, being able to grow back their tail or even form two whole flatworms when cut in half.

How do planarians demonstrate memory retention even after losing their brain?

Planarians can retain memories after decapitation. After regrowing their heads, they still show signs of previous training, suggesting that memories may be stored in other parts of their body, outside the brain.

Why are planarians considered useful for studying brain evolution?

Planarians' simple brains, which control sensory reception and nervous functions, are seen as an analog for how early brains may have functioned, making them useful for studying brain evolution and fundamental questions about memory.

What behaviors can planarians be trained to perform?

Planarians can be trained to overcome their aversion to light when presented with food, and they can adapt to changes in their environment, such as moving from smooth to textured petri dishes.

How long can planarians retain memories after training?

Planarians have been found to retain memories for at least 14 days after being trained to adapt to new environments.

What happens to planarians after their heads are cut off?

When planarians lose their heads, they can regrow new, functional heads within a week, including a new brain capable of sensory functions and eating.

What did the 2013 study reveal about planarians' memory retention post-decapitation?

The 2013 study revealed that planarians retained some memory of their training after regrowing their heads, although the memory retention was not as strong as before decapitation.

How do planarians store memories outside their brain?

One theory is that planarians store memories in neural tissue outside of the brain, which is a surprising discovery since memory is traditionally thought to be confined to the brain.

How could studying planarians potentially benefit human medicine?

If human memories are also stored outside of the brain, like in planarians, this understanding could lead to breakthroughs in treating brain injuries, memory loss, or dementias.

What is CuriosityStream, and what type of content does it offer?

CuriosityStream is a subscription streaming service offering over 2,400 documentaries and nonfiction titles, including original content, focusing on a wide range of topics like nature, science, and history.