This meta-analysis reviews 208 laboratory studies of acute psychological stressors and tests a theoretical model delineating conditions capable of eliciting cortisol responses. Psychological stressors increased cortisol levels; however, effects varied widely across tasks. Consistent with the theoretical model, motivated performance tasks elicited cortisol responses if they were uncontrollable or characterized by social-evaluative threat (task performance could be negatively judged by others), when methodological factors and other stressor characteristics were controlled for. Tasks containing both uncontrollable and social-evaluative elements were associated with the largest cortisol and adrenocorticotropin hormone changes and the longest times to recovery. These findings are consistent with the animal literature on the physiological effects of uncontrollable social threat and contradict the belief that cortisol is responsive to all types of stressors.

http://anthro.vancouver.wsu.edu/media/Course_files/anth-260-edward-h-hagen/acute-stressors-and-cortisol-responses-a-theoretical-integration-and-synthesis-of-laboratory-research-1.pdf

Acute stressors and cortisol responses: a theoretical integration and synthesis of laboratory research.

The adolescent brain and age-related behavioral manifestations

Here we provide a review of the animal and human literature concerning the role of the amygdala in fear conditioning, considering its potential influence over autonomic and hormonal changes, motor behavior and attentional processes. A stimulus that predicts an aversive outcome will change neural transmission in the amygdala to produce the somatic, autonomic and endocrine signs of fear, as well as increased attention to that stimulus. It is now clear that the amygdala is also involved in learning about positively valenced stimuli as well as spatial and motor learning and this review strives to integrate this additional information. A review of available studies examining the human amygdala covers both lesion and electrical stimulation studies as well as the most recent functional neuroimaging studies. Where appropriate, we attempt to integrate basic information on normal amygdala function with our current understanding of psychiatric disorders, including pathological anxiety.

The amygdala: vigilance and emotion

Identification of an endogenous 2-monoglyceride, present in canine gut, that binds to cannabinoid receptors.

The survival and well-being of all species requires appropriate physiological responses to environmental and homeostatic challenges. The re-establishment and maintenance of homeostasis entails the coordinated activation and control of neuroendocrine and autonomic stress systems. These collective stress responses are mediated by largely overlapping circuits in the limbic forebrain, the hypothalamus and the brainstem, so that the respective contributions of the neuroendocrine and autonomic systems are tuned in accordance with stressor modality and intensity. Limbic regions that are responsible for regulating stress responses intersect with circuits that are responsible for memory and reward, providing a means to tailor the stress response with respect to prior experience and anticipated outcomes.

Neural regulation of endocrine and autonomic stress responses.

The feedback effect of systemically administered dexamethasone on basal plasma corticosterone levels and on adrenocortical responses to ether plus skin incision stress were studied in intact rats and in animals with bilateral dorsal or ventral hippocampectomy or fimbria section. It was found that in rats with ventral hippocampectomy or fimbria section, the degree of the feedback was similar to that in intact rats. However, in animals with dorsal hippocampectomy, the inhibitory effect of dexamethasone on basal and stress-induced adrenocortical responses was significantly reduced. These results taken together with previous observations, that section of the dorsal fornix has a similar effect, suggest that dexamethasone exerts its influence on the brain and that the dorsal hippocampal formation participates in the feedback regulation of pituitary-adrenal function. It cannot be excluded, however, that dexamethasone may exert its influence on the pituitary, and the effect observed may be summation of dexamethasone action on the pituitary plus lack of hippocampal input.

Participation of the dorsal hippocampus in the glucocorticoid feedback effect on adrenocortical activity.

Limbic pathways and hypothalamic neurotransmitters mediating adrenocortical responses to neural stimuli.

Anandamide (arachidonylethanolamide), an endogenous ligand of the cannabinoid receptor, was recently isolated from porcine brain. We report here for the first time on the effect of this ligand on the

Effect of the brain constituent anandamide, a cannabinoid receptor agonist, on the hypothalamo-pituitary-adrenal axis in the rat.

Differential effect of amygdaloid lesions on CRF-41, ACTH and corticosterone responses following neural stimuli.

The Excitatory Effects of the Amygdala on Hypothalamo-Pituitary-Adrenocortical Responses Are Mediated by Hypothalamic Norepinephrine, Serotonin, and CRF-41

Shaul Feldman

Papers

Participation of the dorsal hippocampus in the glucocorticoid feedback effect on adrenocortical activity.

Limbic pathways and hypothalamic neurotransmitters mediating adrenocortical responses to neural stimuli.

Effect of the brain constituent anandamide, a cannabinoid receptor agonist, on the hypothalamo-pituitary-adrenal axis in the rat.

Differential effect of amygdaloid lesions on CRF-41, ACTH and corticosterone responses following neural stimuli.

The Excitatory Effects of the Amygdala on Hypothalamo-Pituitary-Adrenocortical Responses Are Mediated by Hypothalamic Norepinephrine, Serotonin, and CRF-41