Planarians Don't Just Regenerate Their Heads, They Regenerate Their Memories (Video)

You might not want to make a worm angry. Ok, it probably doesn't really matter since the average planarian is about half an inch (1.3 cm) long.

In any case, we've heard that when you cut these guys in half, they have the amazing regenerative power to grow their body back. What not everyone previously knew, however, is that if you step on one of these guys and crush their heads, they actually regenerate the same brain and memories previously held before. Translation: It doesn't take them long to relearn lost skills and remember past memories.

To test this theory further, researchers measured several planarians and then set them in a controlled setting to find food following decapitation. Background information from the study reveals that these small worms dislike open spaces and bright light--the environment in which they were placed by the researchers to find their meals. Yet even following decapitation, worms that had gone through training were able to overcome their fears and find food faster than those who had not gone through the experience of relearning their skills.

Scientists are uncertain as to why this happens. Researchers note that their amazing ability to restore their skills may mean that some of their memories could be located elsewhere in the body. Alternatively, worms' original brain may have modified their nervous systems.

All we know is we're glad planarians are small.

More information regarding this study can be found in the Journal of Experimental Biology. 

Want to see a planarian doing it's thing? Check out this video, courtesy of YouTube.