Learned helplessness in flies and the roots of depression

Apr 18, 2013
Learned helplessness in flies and the roots of depression
When faced with impossible circumstances beyond their control, animals, including humans, often hunker down as they develop sleep or eating disorders, ulcers, and other physical manifestations of depression. Now, researchers reporting in the Cell Press journal Current Biology on April 18 show that the same kind of thing happens to flies. Credit: Current Biology, Yang et al.

When faced with impossible circumstances beyond their control, animals, including humans, often hunker down as they develop sleep or eating disorders, ulcers, and other physical manifestations of depression. Now, researchers reporting in the Cell Press journal Current Biology on April 18 show that the same kind of thing happens to flies.

The study is a step toward understanding the for depression and presents a new way for testing , the researchers say. The discovery of such symptoms in an insect shows that the roots of depression are very deep indeed.

"Depressions are so devastating because they go back to such a basic property of behavior," says Martin Heisenberg of the Rudolf Virchow Center in Würzburg, Germany.

Heisenberg says that the idea for the study came out of a lengthy discussion with a colleague about how to ask whether flies can feel fear. Franco Bertolucci, a coauthor on the study, had found that flies can rapidly learn to suppress innate behaviors, a phenomenon that is part of learned helplessness.

The researchers now show that flies experiencing uncomfortable levels of heat will walk to escape it. But if the flies realize that the heat is beyond their control and can't be avoided, they will stop responding, walking more slowly and taking longer and more frequent rests, as if they were "depressed."

Intriguingly, female flies slow down more under those than males do. It's not clear exactly what that means, but Heisenberg explains, "if we realize that the fly trapped in a strange, dark box, unable to get rid of the dangerous heat pulses, has to find a compromise between and not missing any chance of escape, we can understand that such a compromise may come out differently for , as their resources and goals in life are different."

Heisenberg's team now intends to explore other questions, such as: How long does the flies' depression-like state last? How does it affect other behaviors, like courtship and aggression? What is happening in their brain? And more.

Heisenberg says that the findings are a reminder of a lesson that children's books are often best at showing: "Animals have lots in common with us humans. They breathe the same air, share many of the same resources, actively explore space, and have distinct social roles. Their brains serve the same purpose, too: they help them to do the right thing."

Explore further: East African honeybees are safe from invasive pests... for now

More information: Current Biology, Yang et al.: "Flies Cope with Uncontrollable Stress by Learned Helplessness." dx.doi.org/10.1016/j.cub.2013.03.054

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User comments : 7

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2 / 5 (4) Apr 18, 2013
A basic tenet of science is control.
Synergy is where control is shared for better or worst.
Perhaps shared helplessness - male/male, male/female, female/female will change outcomes already known for individuals.
2.3 / 5 (3) Apr 18, 2013
This happens in the real world as well.

In America the Republican states have become helpless and are parasites on the productive Democratic states.

3.3 / 5 (3) Apr 18, 2013
The implicit assumption is that all depression has the same cause. Other universals include low brain serotonin levels.

In all cases, any symptom of depression can be the cause or the consequence of depression e.g. a person experiencing depression because of low serotonin will also experience learned helplessness and a person who experiences learned helplessness will also have low serotonin levels. There are other symptoms of depression that have the same kind of dual role.
5 / 5 (1) Apr 19, 2013
Ouch, political trolling.

@RKS: It is an evolutionary constraint, so seeing the homologous traits tests basic biology. This has passed the ad hoc "assumption" (constraint) case.

I don't think they have checked serotonin, assuming flies use it. But I may be wrong.
1.7 / 5 (3) Apr 19, 2013
Is there an alternative to helplessness in the face of the impossible - (impending, immediate, and inevitable death in this experiment?)
Synthetically manipulating chemical composition to change a state of helplessness to any other state in the face of imminent, immediate, inevitable and impending death does not make sense to me. As if alternating a state arising naturally from an unavoidably outcome is preferred to a natural response (state). Is fear followed by resignation followed by despondence follow by helplessness an aversion in the face of immediate death?
not rated yet Jun 01, 2013
Depression is a very specific condition in humans as is learned helplessness.

Importantly, the two are separate conditions and it is easily possible for them to occur separately ie depression without learned helplessness and learned helplessness without depression.

Thus the fly study and human depression are unrelated or, if they are elated, the study has done nothing whatsoever to establish a connection.

They have simply made the assumption that 'learned helplessness' and depression are linked. They aren't, at least they are not linked in the DSM IV TR, DSM V or the IDC 10, which are the manuals used throughout the world to identify depression.

Thus the study is wrong in making any connection without first establishing if the two conditions are connected and if so, how. It is extremely unlikely that flies have a subjective emotional state comparable to depression and if that is proposed, then that is a philosophical and not a scientific proposal...
not rated yet Jun 01, 2013
The serotonin theory superseded:

Still, I insist you adhered to your beliefs. Readers need entertainment.

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