Animal studies show that high cortisol levels exert their effect on stressful task performance via modulation of the amygdala. Availability of noradrenaline in this brain region appears to be a critical prerequisite for this effect. This relationship between noradrenaline and cortisol is explained by an animal model where the amygdala constitutes a crucial region for this interaction. In humans this model has not been extensively tested so far. In a previously reported study human subjects (aged 20.93+/-2.38) were scanned using fMRI when watching sets of emotional and neutral pictures after taking the beta-adrenergic antagonist propranolol or placebo. Stimulus sets consisted of 92 pictures, divided in four emotional categories that ranged from neutral scenes of domestic objects (CAT1) to extremely negative scenes of mutilation or accidents (CAT4). Confrontation with arousing emotional pictures, accompanied by increased noradrenaline levels, evoked increased amygdala activation under placebo but not under betablocker condition. This new and additional analysis of this data set was carried out to determine the effect of differential endogenous cortisol levels on amygdala activation. Cortisol levels during scanning were determined using salivary samples and subjects were post hoc divided in a High (n=14) and Low cortisol group (n=14). When subjects were watching emotional stimuli, presumably associated with enhanced noradrenaline (NA) levels, amygdala activation was contrasted between the two cortisol groups. We hypothesized that emotional stimuli would elicit more amygdala activation in the High than in the Low cortisol group. Here we demonstrate indeed a significant interaction effect of the endogenous cortisol level with increasing activation in the amygdala under placebo but not under betablocker condition, thereby extending the rodent based model of a synergistic effect of the two stress hormones to the human.
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http://dx.doi.org/10.1016/j.nlm.2006.05.008 | DOI Listing |
J Ethnopharmacol
December 2024
Central Laboratory, Shuguang Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai, China. Electronic address:
Ethnopharmacological Relevance: Epimedium Tourn. ex L. is a traditional Chinese medicine used for thousands of years in China to treat forgetfulness.
View Article and Find Full Text PDFProg Neurobiol
December 2024
Department of Physiology, School of Basic Medical Sciences, Anhui Medical University, Hefei, PR China. Electronic address:
In response to stressors, individuals manifest varied behavioral responses directed toward satisfying physiological survival needs. Although the enduring effects of adolescent stress on both humans and animals are well-documented, the underlying mechanisms remain insufficiently elucidated. Utilizing immunofluorescence, viral injections, and brain slice electrophysiological recordings, we have delineated that heightened excitability among glutamatergic neurons in the basolateral amygdala (BLA) is responsible for inducing heightened exploratory behaviors in adolescent mice subjected to mild, chronic restraint stress.
View Article and Find Full Text PDFMajor Depressive Disorder (MDD) poses a significant public health challenge due to its high prevalence and the substantial burden it places on individuals and healthcare systems. Real-time functional magnetic resonance imaging neurofeedback (rtfMRI-NF) shows promise as a treatment for this disorder, although its mechanisms of action remain unclear. This study investigated whole-brain response patterns during rtfMRI-NF training to explain interindividual variability in clinical efficacy in MDD.
View Article and Find Full Text PDFAlcohol Clin Exp Res (Hoboken)
December 2024
Integrated Program in Neuroscience, McGill University, Montreal, Quebec, Canada.
Background: Adolescent alcohol use is the norm, but only some develop a substance use disorder. The increased risk might reflect heightened mesocorticolimbic responses to reward-related cues but results published to date have been inconsistent.
Methods: Young social drinkers (age 18.
Neuropharmacology
December 2024
Department of Psychology, Center for Development and Behavioral Neuroscience, Binghamton University, Binghamton NY 13902, United States; Developmental Exposure Alcohol Research Center, Binghamton NY 13902, United States. Electronic address:
Individuals with prenatal alcohol exposure (PAE) are at a higher risk for developing alcohol use disorder (AUD). Using a rat model of moderate PAE (mPAE) on gestational day 12 (G12; ∼2 trimesters in humans), a critical period for amygdala development, we have shown disruptions in medial central amygdala (CeM) function, an important brain region associated with the development of AUD. In addition to this, acute ethanol (EtOH) increases GABA transmission in the CeM of rodents in a sex-dependent manner, a mechanism that potentially contributes to alcohol misuse.
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