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Low-frequency fluctuations in fMRI signal have been used to map several consistent resting state networks in the brain. Using the posterior cingulate cortex as a seed region, functional connectivity analyses have found not only positive correlations in the default mode network but negative correlations in another resting state network related to attentional(More)
The analysis of functional connectivity in fMRI can be severely affected by cardiac and respiratory fluctuations. While some of these artifactual signal changes can be reduced by physiological noise correction routines, signal fluctuations induced by slower breath-to-breath changes in the depth and rate of breathing are typically not removed. These slower(More)
Resting-state functional magnetic resonance imaging (RS-FMRI) holds the promise of revealing brain functional connectivity without requiring specific tasks targeting particular brain systems. RS-FMRI is being used to find differences between populations even when a specific candidate target for traditional inferences is lacking. However, the problem with(More)
Recent advances in MRI receiver and coil technologies have significantly improved image signal-to-noise ratios (SNR) and thus temporal SNR (TSNR). These gains in SNR and TSNR have allowed the detection of fMRI signal changes at higher spatial resolution and therefore have increased the potential to localize small brain structures such as cortical layers and(More)
We combined the data of five event-related fMRI studies of response inhibition. The re-analysis (n = 71) revealed response inhibition to be accomplished by a largely right hemisphere network of prefrontal, parietal, subcortical and midline regions, with converging evidence pointing to the particular importance of the right frontal operculum. Functional(More)
CONTEXT Mutation of the G protein-coupled receptor 54 is associated with a failure of reproductive function. The endogenous neuropeptide agonist for G protein-coupled receptor 54, kisspeptin, potently stimulates the hypothalamic-pituitary-gonadal axis in rodents and primates. OBJECTIVE The present study was designed to determine the effects of elevating(More)
Psychedelic drugs have a long history of use in healing ceremonies, but despite renewed interest in their therapeutic potential, we continue to know very little about how they work in the brain. Here we used psilocybin, a classic psychedelic found in magic mushrooms, and a task-free functional MRI (fMRI) protocol designed to capture the transition from(More)
Ghrelin, a novel 28 amino acid peptide found in hypothalamus and stomach, was recently identified as the endogenous ligand for the growth hormone secretagogue receptor (GHS-R). We have now found that both intracerebroventricular (i.c.v.) and intraperitoneal (i.p.) administration of ghrelin in freely feeding rats stimulated food intake. The onset of(More)
Apelin is the recently identified endogenous ligand for the G-protein-coupled receptor, APJ. Preproapelin and APJ mRNA are found in hypothalamic regions known to be important in the regulation of food and water intake, and pituitary hormone release. The effects of intracerebroventricular (ICV) administration of pyroglutamylated apelin-13 on food and water(More)
The goal of resting-state functional magnetic resonance imaging (fMRI) is to investigate the brain's functional connections by using the temporal similarity between blood oxygenation level dependent (BOLD) signals in different regions of the brain "at rest" as an indicator of synchronous neural activity. Since this measure relies on the temporal correlation(More)