Inescapable Stress Changes Walking Behavior in Flies - Learned Helplessness Revisited

Flies Cope with Uncontrollable Stress by Learned Helplessness

In a wide range of animals, uncontrollable stressful events can induce a condition called "learned helplessness." In mammals it is associated with low general activity, poor learning, disorders of sleep and feeding, ulcers, and reduced immune status, as well as with increased serotonin in parts of the brain. It is considered an animal model of depression in humans. Here we investigate learned h...

Behavior under uncontrollable stress in Drosophila melanogaster – Learned Helplessness revisited

The influence of gender and the estrous cycle on learned helplessness in the rat.

Although the etiology of clinical depression is unknown, women are more likely to suffer from major depressive disorder than men. In addition, in some women, there is a clear association between depression and specific phases of the menstrual cycle. Surprisingly little research has examined gender differences and the influences of the estrous cycle in this and other animal behavioral models of ...

Learned helplessness is independent of levels of brain-derived neurotrophic factor in the hippocampus.

Reduced levels of brain-derived neurotrophic factor (BDNF) in the hippocampus have been implicated in human affective disorders and behavioral stress responses. The current studies examined the role of BDNF in the behavioral consequences of inescapable stress, or learned helplessness. Inescapable stress decreased BDNF mRNA and protein in the hippocampus of sedentary rats. Rats allowed voluntary...

The role of the habenular complex in the elevation of dorsal raphe nucleus serotonin and the changes in the behavioral responses produced by uncontrollable stress.

Previous research indicates that the serotonergic neurons of the caudal dorsal raphe nucleus (DRN) are activated to a greater degree by inescapable shock (IS) as compared to escapable shock (ES), causing a greater release of serotonin (5-HT) in the DRN and in target regions. This differential activation is necessary for the behavioral changes that occur after exposure to IS, but not to ES (i.e....