Introduction: Recently, human studies using exposure therapy to treat anxiety have demonstrated that pretreatment with D-cycloserine (DCS) enhances fear reduction in anxiety disorders. However, the underlying brain mechanisms mediating this fear reduction have yet to be determined.
Methods: The effects of orally administered DCS on amygdala activity during the processing of repeated facial expressions were examined in this double-blind study. Fourteen healthy males (30.0+/-8.7 years of age) randomly received DCS 500 mg or placebo prior to 3.0 Tesla functional magnetic resonance imaging acquisition. All participants viewed four separate runs, consisting of a single block of a repeated facial expression (happy or fearful) bracketed by fixation blocks.
Results: Anatomic region-of-interest analyses showed that the placebo group exhibited amygdala activation and response habituation, while the DCS group displayed blunted amygdala responses to emotional faces across the experiment, whereby habituation was not detected.
Conclusion: This finding may have relevance for testing treatments of anxiety and depression.
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http://dx.doi.org/10.1017/s1092852900021398 | DOI Listing |
Brain Commun
December 2024
Division of Psychiatry, University College London, London W1T 7NF, UK.
Hyperphosphorylated tau accumulation is seen in the noradrenergic locus coeruleus from the earliest stages of Alzheimer's disease onwards and has been associated with symptoms of agitation. It is hypothesized that compensatory locus coeruleus-noradrenaline system overactivity and impaired emotion regulation could underlie agitation propensity, but to our knowledge this has not previously been investigated. A better understanding of the neurobiological underpinnings of agitation would help the development of targeted prevention and treatment strategies.
View Article and Find Full Text PDFJ Comp Neurol
January 2025
Department of Neurology, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts, USA.
The parabrachial nucleus (PB), located in the dorsolateral pons, contains primarily glutamatergic neurons that regulate responses to a variety of interoceptive and cutaneous sensory signals. One lateral PB subpopulation expresses the Calca gene, which codes for the neuropeptide calcitonin gene-related peptide (CGRP). These PB neurons relay signals related to threatening stimuli such as hypercarbia, pain, and nausea, yet their inputs and their neurochemical identity are only partially understood.
View Article and Find Full Text PDFActa Physiol (Oxf)
February 2025
Department of Physiology, Graduate School of Health and Sports Science, Juntendo University, Chiba, Japan.
Aim: Chronic stress elevates blood pressure, whereas regular exercise exerts antistress and antihypertensive effects. However, the mechanisms of stress-induced hypertension and preventive effects through exercise remain unknown. Thus, we investigated the molecular basis involved in autonomic blood pressure regulation within the amygdala.
View Article and Find Full Text PDFSci Rep
January 2025
Center for Molecular and Behavioral Neuroscience, Rutgers University, Newark, NJ, 07102, USA.
In vitro studies have shown that a neuron's electroresponsive properties can predispose it to oscillate at specific frequencies. In contrast, network activity in vivo can entrain neurons to rhythms that their biophysical properties do not predispose them to favor. However, there is limited information on the comparative frequency profile of unit entrainment across brain regions.
View Article and Find Full Text PDFDev Cogn Neurosci
January 2025
Department of Medical Sciences, Experimental Cognitive and Affective Neuroscience Lab, Uppsala University, Uppsala, Sweden. Electronic address:
Past results suggest that fear extinction and the return of extinguished fear are compromised in adolescents. However, findings have been inconclusive as there is a lack of fear extinction and extinction retention studies including children, adolescents and adults. In the present study, 36 children (6-9 years), 40 adolescents (13-17 years) and 44 adults (30-40 years), underwent a two-day fear conditioning task.
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