New research reveals that, just like human teenagers, worms go through a dopey adolescent phase during which they lack focus and are easily distracted from their responsibilities. However, rather than simply going off the rails and acting disobediently, scientists believe the animals may avoid the straight-and-narrow in order to gain a wider variety of experiences, thereby learning more about their environment before eventually developing a sense of purpose and direction in adulthood.
Nematodes are particularly partial to a chemical called diacetyl, which also happens to be popular among humans as it has the smell of buttered popcorn.
When researchers placed nematodes of different ages in a dish with a drop of diacetyl, they found that adult worms headed straight to the food source, but adolescent specimens tended to take a less direct route, exploring various parts of the dish and sometimes never making it to the food at all.
To figure out why younger worms are so easily distracted, the team then used molecular techniques that caused neurons in the creatures’ brains to become illuminated when active. They were particularly interested in observing a pair of neurons called AWA, which are responsible for detecting the smell of diacetyl.
Describing their findings in the journal eNeuro, the study authors explain that AWA only responded to high concentrations of diacetyl in adolescent nematodes, but was able to pick up much weaker traces of the chemical in adults.
Furthermore, three other sets of neurons called AWB, ASK, and AWC all became activated in adults, but not adolescents, when diacetyl was present.
This suggests that as the nematodes reach adulthood they develop age-specific neural circuits that control their behavior, making them more focused and efficient when it comes to fulfilling life’s obligations, such as finding food.
In contrast, study co-author Laura Hale explained in a statement that younger worms act like “angsty teens” who respond to the presence of food by saying “yeah, I know I'm supposed to go over there but I just don't feel like it.”
The researchers believe that this attitude enables the young worms to develop flexible behaviors, as opposed to the rigid discipline of their elders, which in turn helps them to learn more about their surroundings.
“Instead of merely being rebellious, teens – both humans and worms – may just be staying flexible to adapt to an unpredictable world,” adds co-author Sreekanth Chalasani.