There are other stressors whose sequelae may well be due to the uncontrollability of the stressor (eg, social defeat), but since controllability cannot be readily manipulated in these paradigms, this cannot

be determined. Indeed, this is why shock is used in our studies. We know of no other selleckchem aversive event whose controllability can readily be manipulated in such a way Inhibitors,research,lifescience,medical that the subjects with and without control experience identical physical events. Research conducted by numerous laboratories has revealed a constellation of behavioral changes that follow uncontrollable, but not controllable, shocks. Thus, rats exposed to uncontrollable shock later fail to learn to escape shock in a different situation (the so-called “learned helplessness” effect), are inactive in the face of aversive events (so-called

“behavioral depression”), become less aggressive and show reduced social dominance, behave anxiously in tests of “anxiety” such as the social interaction test, are neophobic, develop ulcers, respond in exaggerated fashion to drugs of abuse, etc.6 Inhibitors,research,lifescience,medical None of these outcomes follow if the organism is able to Inhibitors,research,lifescience,medical exert control over the stressor. Prior research has focused on the neural mechanism(s) by which uncontrollable stress (inescapable shock, IS) leads to the above behavioral outcomes. Indeed, this can be said of most stress research in animals, since the stres sors that are used (restraint, social defeat, Inhibitors,research,lifescience,medical cold water, etc) have almost always been uncontrollable. There has been very little work directed at understanding the mechanism(s) by which control confers protection from the effects of the stressor. Indeed, most experiments studying the neurobiology of stress do not even contain a group for whom the stressor is controllable – the typical comparison is between a group exposed to an uncontrollable stressor and a home

cage control group. What is known is that uncontrollable stress produces sequelae Inhibitors,research,lifescience,medical that are not produced by physically identical controllable stress. It has been implicitly assumed that this difference occurs because the organism detects/learns/perceives that the uncontrollable stressor is Rutecarpine uncontrollable, and that this sets in motion the neural cascade that mediates the behavioral outcomes. The unstated assumption has been that stress per se produces neural consequences that are then magnified by the detection/learning/perception of uncontrollability That is, it has been assumed that uncontrollability is the “active ingredient.” From this point of view, controllable stressors fail to produce outcomes such as exaggerated anxiety simply because they lack the active uncontrollability element. However, it is also possible that instead the presence of control is the “active ingredient.” Here, the detection/learning/perception of control would inhibit neural responses to stressors.