| Online: | |
| Visits: | |
| Stories: |
Do fruit flies get scared?
Brett Smith for redOrbit.com – Your Universe Online
We know that dogs, cats, and other animals experience basic feelings like excitement before being fed or fear of discipline, but what about insects? Do wasps get angry when you swat at them? Do ants become sad when we inadvertently step on their colleagues?
In a new study published by the journal Current Biology, researchers found that Drosophila fruit flies do exhibit symptoms of fear in response to shadows passing quickly overhead.
“No one will argue with you if you claim that flies have four fundamental drives just as humans do: feeding, fighting, fleeing, and mating,” study author William T. Gibson, a Caltech postdoctoral fellow, said in a press release. “Taking the question a step further–whether flies that flee a stimulus are actually afraid of that stimulus–is much more difficult.”
Defining fear in fruit flies
In order to see if flies feel fear, researchers first had to define it. Gibson said his team laid four essential components of fear.
First, the team noted that fear is persistent. For example, the sudden sound of a gunshot can provoke a lasting sensation of fear. The researchers also said fear is also scalable, meaning additional gunshots can increase that initial sensation of fear. Third and fourth, the study team said, fear is cuts across different contexts and situations. To extend the initial example, once you’ve been spooked by that first gunshot, you’re more likely to jump in response to the slam of a door or a dropped glass shattering on the floor.
After laying out these components, the team attempted to see if they could provoke all four in fruit flies using shadows passing overhead as the stimulus (poor little guys). The team carefully examined the flies’ behaviors on video, which revealed that shadows set off increasing and persistent upticks in the flies’ movement and hopping.
From time to time, the insects froze in place, a defensive response also witnessed in the fearful rodents. The shadows also triggered hungry flies to leave a food source, indicating that the stimulus was negative and generalized from one situation to another, the researchers said.
The researchers also saw that it took a while before spooked flies would return to their food, suggesting a slow rolling back of the insects’ internal, defensive state. Also, the more shadows the flies were exposed to, the longer it took for the symptoms of fear to subside, proof of the team’s second ‘tenet of fear.’
“The argument that this paper makes is that the Drosophila system may be an excellent model for emotion states due to the relative simplicity of its nervous system, combined simultaneously with the behavioral complexity it exhibits,” Gibson said.
—–
Follow redOrbit on Twitter, Facebook, Google+, Instagram and Pinterest.
redOrbit.com
offers Science, Space, Technology, Health news, videos, images and
reference information. For the latest science news, space news,
technology news, health news visit redOrbit.com frequently. Learn
something new every day.”
Source: http://www.redorbit.com/news/science/1113391911/do-fruit-flies-get-scared-051515/
