Biological psychiatry
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Biological psychiatry · Feb 2010
Aversive imagery in posttraumatic stress disorder: trauma recurrence, comorbidity, and physiological reactivity.
Posttraumatic stress disorder (PTSD) is characterized as a disorder of exaggerated defensive physiological arousal. The novel aim of the present research was to investigate within PTSD a potential dose-response relationship between past trauma recurrence and current comorbidity and intensity of physiological reactions to imagery of trauma and other aversive scenarios. ⋯ Whereas PTSD patients generally show marked physiological arousal during aversive imagery, concordant with self-reported distress, the most symptomatic patients with histories of severe, cumulative traumatization show discordant physiological hyporeactivity, perhaps attributable to sustained high stress and an egregious, persistent negative affectivity that ultimately compromises defensive responding.
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Biological psychiatry · Feb 2010
5-hydroxytryptamine 2C receptors in the basolateral amygdala are involved in the expression of anxiety after uncontrollable traumatic stress.
Exposure to uncontrollable stressors often increases anxiety-like behavior in both humans and rodents. In rat, this effect depends on stress-induced activity within the dorsal raphe nucleus (DRN). However, the role of serotonin in DRN projection regions is largely unknown. The goals of this study were to 1) assess the effect of uncontrollable stress on extracellular serotonin in the basolateral amygdala during the anxiety test, 2) determine whether DRN activity during a poststress anxiety test is involved in anxiety-like behavior, and 3) determine the role of the serotonin 2C receptor (5-HT(2C)) in uncontrollable stress-induced anxiety. ⋯ These results suggest that the anxiety-like behavior observed after uncontrollable stress is mediated by exaggerated 5-HT acting at BLA 5-HT(2C) receptors.