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Numerous studies have reported that long‐term musical training can affect brain functionality and induce structural alterations in the brain. Singing is a form of vocal musical expression with an unparalleled capacity for communicating emotion; however, there has been relatively little research on neuroplasticity at the network level in vocalists (i.e., noninstrumental musicians). Our objective in this study was to elucidate changes in the neural network architecture following long‐term training in the musical arts. We employed a framework based on graph theory to depict the connectivity and efficiency of structural networks in the brain, based on diffusion‐weighted images obtained from 35 vocalists, 27 pianists, and 33 nonmusicians. Our results revealed that musical training (both voice and piano) could enhance connectivity among emotion‐related regions of the brain, such as the amygdala. We also discovered that voice training reshaped the architecture of experience‐dependent networks, such as those involved in vocal motor control, sensory feedback, and language processing. It appears that vocal‐related changes in areas such as the insula, paracentral lobule, supramarginal gyrus, and putamen are associated with functional segregation, multisensory integration, and enhanced network interconnectivity. These results suggest that long‐term musical training can strengthen or prune white matter connectivity networks in an experience‐dependent manner. [ABSTRACT FROM AUTHOR]

Aim: Fibromyalgia is often comorbid with depression, and less than half those patients achieve satisfactory improvement after adequate pharmacological intervention. The investigation of repetitive transcranial magnetic stimulation (rTMS) at left dorsolateral prefrontal cortex for modified‐2010 American College of Rheumatology (ACR) fibromyalgia and major depressive disorder (MDD) is still in its infancy. Methods: In this double‐blind, randomized, sham‐control study, subjects diagnosed with ACR‐2010 fibromyalgia and DSM‐IV‐TR MDD were recruited and received either active or sham interventions for 2 weeks. Hamilton Depression Rating Scale (HDRS) and the 10‐cm visual analogue pain scale were evaluated at baseline, week 1, and week 2. Multivariable generalized estimating equations analysis was performed for the association between depression and pain scores at each checkpoint. Results: Twenty subjects were recruited. There was a significant difference over the 2 weeks between the rTMS and sham stimulation groups (P = 0.029), but subgroup analyses were further performed due to significant interaction of group and HDRS on pain outcomes (P = 0.020). The active group had significant improvement in pain at week 2 compared with week 1 (P = 0.021), but the control group did not have any improvement in pain (P = 0.585). Of the mild–moderate depression patients, the pain score in the active group was significantly lower than in the sham group at week 1 (P = 0.001) and at week 2 (P < 0.001). For the severe depression group, there was significantly lower pain over the 2 weeks in the active group (P = 0.045) but the sham group had significantly relapsing pain at week 2 (P < 0.001). Conclusion: Left prefrontal rTMS has an analgesic effect in modified‐ACR 2010‐defined fibromyalgia and MDD patients. Further investigation is required, however, in order to determine how to regulate the different rTMS treatment protocols according to individual baseline depression severity in patients with MDD and fibromyalgia. [ABSTRACT FROM AUTHOR]

Objectives Bipolar I disorder ( BD) is a highly heritable disorder characterized by mood swings between high-energy and low-energy states. Amygdala hyperactivity and cortical inhibitory hypoactivity [e.g., of the dorsolateral prefrontal cortex (dl PFC)] have been found in patients with BD, as evidenced by their abnormal resting-state functional connectivity ( FC) and glucose utilization ( GU). However, it has not been determined whether functional abnormalities of the dl PFC-amygdala circuit exist in unaffected, healthy siblings of the patients with BD ( BDsib). Methods Twenty euthymic patients with BD, 20 unaffected matching BDsib of the patient group, and 20 well-matched healthy control subjects were recruited. We investigated seed-based FC (seeds: dl PFC) with resting-state functional magnetic resonance imaging and GU in the regions of interest (e.g., dl PFC and amygdala) using 18F-fluorodeoxyglucose positron emission tomography. Results The FC in the dl PFC (right)-amygdala circuit was statistically abnormal in patients with BD and BDsib, but only the patients with BD demonstrated hypoactive GU bilaterally in the dl PFC and hyperactive GU bilaterally in the amygdala. Facilitating differentiation between the BD groups, the altered FC between dl PFC (right) and amygdala (left) was even more prominent in the patients with BD (p < 0.05). Conclusions There was a dysfunctional connection with intact GU in the dl PFC-amygdala circuit of the BDsib, which highlights the vulnerability in families with BD. Diminished top-down control from the bilateral dl PFC, which prevents adequate inhibition of limbic hyperactivity, might mediate the development of BD. [ABSTRACT FROM AUTHOR]

Li C-T, Hsieh J-C, Wang S-J, Yang B-H, Bai Y-M, Lin W-C, Lan C-C, Su T-P. Differential relations between fronto-limbic metabolism and executive function in patients with remitted bipolar I and bipolar II disorder. Bipolar Disord 2012: 14: 831-842. © 2012 John Wiley & Sons A/S. Published by Blackwell Publishing Ltd. Objectives: The aim of this study was to investigate the relationship between resting brain glucose metabolism and cognitive profiles in patients with remitted bipolar I disorder (BD-I) and bipolar II disorder (BD-II). We hypothesized that BD-I patients (compared to BD-II patients) would perform worse on tests of cognitive function because of abnormal metabolism in the prefrontal cortex and other mood-related brain areas. Methods: Thirty-four patients with remitted bipolar disorder (BD) (BD-I = 17, BD-II = 17) under treatment and 17 well-matched healthy controls received both fluorodeoxyglucose (18F-FDG) positron emission tomography (PET) and neuropsychological tests of attention, memory, and executive function. Results: Clinical features in patients with BD-I and BD-II were comparable. Executive function, as indicated by performance on the Wisconsin Card Sorting Test, was significantly worse (i.e., higher percentage of errors, lower percentage of conceptual level responses, and fewer categories completed) in BD-I patients than in BD-II patients and healthy subjects. No difference in attention and memory tests was found among these three groups. Brain PET analysis showed that BD-I patients (compared to BD-II patients) had significantly lower glucose uptake in the bilateral anterior cingulum, insula, striatum, and part of the prefrontal cortex, and higher glucose uptake in the left parahippocampus. Further analyses revealed significant correlations between poor executive function and abnormal glucose uptake in other brain areas in BD-I patients. Conclusions: There are neurobiological differences between subtypes of BD. BD-I is associated with more impaired fronto-limbic circuitry, which might account for reduced executive function in BD-I patients during remission. [ABSTRACT FROM AUTHOR]

Although regional differences in cerebral volume have been revealed in developing human brains, little is known regarding the regionalization of cortical shape. This study documented the regional and quantitative shape difference of cortical surfaces for in utero normal fetal brains over a time period essential for the formation of primary cortical folding (22-33 weeks). Each brain surface with complete three-dimensional morphology was manually extracted from the reconstructed image, which combined surface information from three orthogonal magnetic resonance images in utero. An innovative parcellation was used to dissect the fetal brains into frontal, parietal, temporal and occipital lobes, and to avoid the determination of non-existent and immature sulci for young fetuses. Distinct cortical shapes were encoded by the shape index automatically. The results of this study show faster shape changes in the occipital lobe than in other regions. Both regional and global shape patterns show that the gyral surface smoothens, whereas the sulcal surface becomes more angular, with gestational age. In addition, the smoothing of gyri is related mainly to the changes in shape of gyral crowns. This study presents the regional differences in early gyrification from the novel aspect of shape. The results of shape pattern analysis for normal fetuses may act as a reference in assessments of prenatal brain pathology and in extensive comparisons between various life stages. [ABSTRACT FROM AUTHOR]

Regional differences in human brain development during infancy have been studied for many years, but little is known about how regionalization of the brain proceeds during intrauterine life. We investigated the regionalization of cerebral volume and cortical convolutions based on the volumetric magnetic resonance images (MRIs) of 43 fetuses, ranging from 21 to 37 weeks of gestation. Two plausible parcellations of MRI are proposed, and curvature index together with gyrification index are used to quantify the regional cortical convolutions. Our results elucidate that the cortical foldings among different brain regions develop at comparable rates, suggesting a similar uniformity of changes in size of the cortical sheet in these regions over time. On the contrary, the growth of the cerebral volume presents regional difference, with the frontal and parieto-temporal regions growing significantly faster than other regions due to the contribution from expansion of basal ganglia. This quantitative regional information suggests that cerebral volume is not a relevant parameter to measure in relation to gyrification, and that the size of the cortical sheet is more likely to be directly related to cortical folding. The availability of quantitative regional information on normal fetal brains in utero will allow clinical application of this information when probing neurodevelopmental disorders in the future. [ABSTRACT FROM AUTHOR]

Frequency-dependent modulation between neuronal assemblies may provide insightful mechanisms of functional organization in the context of neural connectivity. We present a conjoined time-frequency cross mutual information (TFCMI) method to explore the subtle brain neural connectivity by magnetoencephalography (MEG) during a self-paced finger lifting task. Surface electromyogram (sEMG) was obtained from the extensor digitorum communis. Both within-modality (MEG-MEG) and between-modality studies (sEMG-MEG) were conducted. The TFCMI method measures both the linear and nonlinear dependencies of the temporal dynamics of signal power within a pre-specified frequency band. Each single trial of MEG across channels and sEMG signals was transformed into time-frequency domain with use of the Morlet wavelet to obtain better temporal spectral (power) information. As compared to coherence approach (linear dependency only) in broadband analysis, the TFCMI method demonstrated advantages in encompassing detection for the mesial frontocentral cortex and bilateral primary sensorimotor areas, clear demarcation of event- and non-event-related regions, and robustness for sEMG - MEG between-modality study, i.e., corticomuscular communication. We conclude that this novel TFCMI method promises a possibility to better unravel the intricate functional organizations of brain in the context of oscillation-coded communication. Hum Brain Mapp, 2008. © 2007 Wiley-Liss, Inc. [ABSTRACT FROM AUTHOR]

The ability to cluster different perfusion compartments in the brain is critical for analyzing brain perfusion. This study presents a method based on a mixture of multivariate Gaussians (MoMG) and the expectation-maximization (EM) algorithm to dissect various perfusion compartments from dynamic susceptibility contrast (DSC) MR images so that each compartment comprises pixels of similar signal-time curves. This EM-based method provides an objective way to 1) delineate an area to serve as the in-plane arterial input function (AIF) of the feeding artery for adjacent tissues to better quantify the relative cerebral blood volume (rCBV), relative cerebral blood flow (rCBF), and mean transit time (MTT); 2) demarcate regions with abnormal perfusion derangement to facilitate diagnosis; and 3) obtain parametric maps with supplementary information, such as temporal scenarios and recirculation of contrast agent. Results from normal subjects show that perfusion cascade manifests (in order of appearance) the arteries, gray matter (GM), white matter (WM), veins and sinuses, and choroid plexus mixed with cerebrospinal fluid (CSF). The averaged rCBV, rCBF, and MTT ratios between GM and WM are in good agreement with those in the literature. Results from a patient with cerebral arteriovenous malformation (CAVM) showed distinct spatiotemporal characteristics between perfusion patterns, which allowed differentiation between pathological and nonpathological areas. Magn Reson Med 57:181-191, 2007. © 2006 Wiley-Liss, Inc. [ABSTRACT FROM AUTHOR]