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Seasonal variation in the brain μ-opioid receptor availability
<p>Seasonal rhythms influence emotion and sociability. The brain μ-opioid receptor (MOR) system modulates a multitude of seasonally varying socioemotional functions, but its seasonal variation remains elusive with no ...
Escitalopram enhances synchrony of brain responses during emotional narratives in patients with major depressive disorder
One-week treatment with escitalopram decreases amygdala responses to fearful facial expressions in depressed patients, but it remains unknown whether it also modulates processing of complex and freely processed emotional ...
On no man’s land: Subjective experiences during unresponsive and responsive sedative states induced by four different anesthetic agents
<p>To understand how anesthetics with different molecular mechanisms affect consciousness, we explored subjective experiences recalled after responsive and unresponsive sedation induced with equisedative doses of dexmedetomidine, propofol, sevoflurane, and S-ketamine in healthy male participants (N = 140). The anesthetics were administered in experimental setting using target-controlled infusion or vapouriser for one hour. Interviews conducted after anesthetic administration revealed that 46.9% (n = 46) of arousable participants (n = 98) reported experiences, most frequently dreaming or memory incorporation of the setting. Participants receiving dexmedetomidine reported experiences most often while S-ketamine induced the most multimodal experiences. Responsiveness at the end of anesthetic administration did not affect the prevalence or content of reported experiences. These results demonstrate that subjective experiences during responsive and unresponsive sedation are common and anesthetic agents with different molecular mechanisms of action may have different effects on the prevalence and complexity of the experiences, albeit in the present sample the differences between drugs were minute.<br></p>...
Cerebral grey matter density is associated with neuroreceptor and neurotransporter availability: A combined PET and MRI study
<a href="https://www.sciencedirect.com/topics/medicine-and-dentistry/positron-emission-tomography" title="Learn more about Positron emission tomography from ScienceDirect's AI-generated Topic Pages">Positron emission tomography</a> (PET) can be used for in vivo measurement of specific <a href="https://www.sciencedirect.com/topics/medicine-and-dentistry/neuroreceptor" title="Learn more about neuroreceptors from ScienceDirect's AI-generated Topic Pages">neuroreceptors</a> and transporters using <a href="https://www.sciencedirect.com/topics/medicine-and-dentistry/radioligand" title="Learn more about radioligands from ScienceDirect's AI-generated Topic Pages">radioligands</a>, while voxel-based morphometric analysis of magnetic resonance images allows automated estimation of local grey matter densities. However, it is not known how regional neuroreceptor or transporter densities are reflected in grey matter densities. Here, we analyzed <a href="https://www.sciencedirect.com/topics/medicine-and-dentistry/brain-scintiscanning" title="Learn more about brain scans from ScienceDirect's AI-generated Topic Pages">brain scans</a> retrospectively from 328 subjects and compared grey matter density estimates with neuroreceptor and transporter availabilities. µ-opioid receptors (MORs) were measured with [11C]carfentanil (162 scans), <a href="https://www.sciencedirect.com/topics/medicine-and-dentistry/dopamine-receptor-d2" title="Learn more about dopamine D2 receptors from ScienceDirect's AI-generated Topic Pages">dopamine D2 receptors</a> with [11C]raclopride (92 scans) and <a href="https://www.sciencedirect.com/topics/medicine-and-dentistry/serotonin-transporter" title="Learn more about serotonin transporters from ScienceDirect's AI-generated Topic Pages">serotonin transporters</a> (SERT) with [11C]MADAM (74 scans). The PET data were modelled with simplified reference tissue model. Voxel-wise correlations between binding potential and grey matter density images were computed. Regional binding of all the used <a href="https://www.sciencedirect.com/topics/medicine-and-dentistry/radioactive-tracer" title="Learn more about radiotracers from ScienceDirect's AI-generated Topic Pages">radiotracers</a> was associated with grey matter density in region and ligand-specific manner independently of subjects’ age or sex. These data show that grey matter density and MOR and D2R neuroreceptor / SERT availability are correlated, with effect sizes (r2) ranging from 0.04 to 0.69. This suggests that future studies comparing PET outcome measure different groups (such as patients and controls) should also analyze interactive effects of grey matter density and PET outcome measures....
Brain free fatty acid uptake is elevated in morbid obesity, and is irreversible 6 months after bariatric surgery: A positron emission tomography study
<h3>Aim</h3><p>To investigate whether there are differences in brain fatty acid uptake (BFAU) between morbidly obese and lean subjects, and the effect of weight loss following bariatric surgery.</p><h3>Materials and ...
Dissociable Roles of Cerebral mu-Opioid and Type 2 Dopamine Receptors in Vicarious Pain: A Combined PET-fMRI Study
Neuroimaging studies have shown that seeing others in pain activates brain regions that are involved in first-hand pain, suggesting that shared neuromolecular pathways support processing of first-hand and vicarious pain. ...
Opioid Release after High-Intensity Interval Training in Healthy Human Subjects
Central opioidergic mechanisms may modulate the positive effects of physical exercise such as mood elevation and stress reduction. How exercise intensity and concomitant effective changes affect central opioidergic responses ...
Affective Adaptation to Repeated SIT and MICT Protocols in Insulin-Resistant Subjects
Introduction The aim of this study was to investigate affective responses to repeated sessions of sprint interval training (SIT) in comparison with moderate-intensity continuous training (MICT) in insulin-resistant ...
Comparative effects of dexmedetomidine, propofol, sevoflurane, and S-ketamine on regional cerebral glucose metabolism in humans: a positron emission tomography study
<p>Introduction: The highly selective alpha(2)-agonist dexmedetomidine has become a popular sedative for neurointensive care patients. However, earlier studies have raised concern that dexmedetomidine might reduce cerebral ...