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Find video protocols related to scientific articles indexed in Pubmed.
Emotion circuits differentiate symptoms of psychosis versus mania in adolescents.
Neurocase
PUBLISHED: 09-30-2014
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The diagnostic boundary between schizophrenia and bipolar disorder can be unclear, particularly with early onset. We assessed if emotion brain circuits differentiate psychosis versus mania symptoms in a series of six early onset patients. Symptoms were dissociated by direction, awareness condition, and brain regions. Greater psychosis symptoms were correlated with greater prefrontal, anterior cingulate, amygdala, and fusiform face area activation during masked fear processing. By contrast, greater mania symptoms were correlated with less amygdala activation during unmasked fear and happy processing. This suggests emotion dysfunction in schizophrenia versus bipolar disorder may arise from partially distinct neural mechanisms of susceptibility.
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Diffusion tensor imaging predictors of treatment outcomes in major depressive disorder.
Br J Psychiatry
PUBLISHED: 06-26-2014
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Functional neuroimaging studies implicate anterior cingulate and limbic dysfunction in major depressive disorder (MDD) and responsiveness to antidepressants. Diffusion tensor imaging (DTI) enables characterisation of white matter tracts that relate to these regions.
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Abnormal structural networks characterize major depressive disorder: a connectome analysis.
Biol. Psychiatry
PUBLISHED: 02-12-2014
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Major depressive disorder (MDD) has been shown to be associated with a disrupted topological organization of functional brain networks. However, little is known regarding whether these changes have a structural basis. Diffusion tensor imaging (DTI) enables comprehensive whole-brain mapping of the white matter tracts that link regions distributed throughout the entire brain, the so-called human connectome.
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Establishing the resting state default mode network derived from functional magnetic resonance imaging tasks as an endophenotype: A twins study.
Hum Brain Mapp
PUBLISHED: 01-22-2014
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The resting state default mode network (DMN) has been shown to characterize a number of neurological and psychiatric disorders. Evidence suggests an underlying genetic basis for this network and hence could serve as potential endophenotype for these disorders. Heritability is a defining criterion for endophenotypes. The DMN is measured either using a resting-state functional magnetic resonance imaging (fMRI) scan or by extracting resting state activity from task-based fMRI. The current study is the first to evaluate heritability of this task-derived resting activity. 250 healthy adult twins (79 monozygotic and 46 dizygotic same sex twin pairs) completed five cognitive and emotion processing fMRI tasks. Resting state DMN functional connectivity was derived from these five fMRI tasks. We validated this approach by comparing connectivity estimates from task-derived resting activity for all five fMRI tasks, with those obtained using a dedicated task-free resting state scan in an independent cohort of 27 healthy individuals. Structural equation modeling using the classic twin design was used to estimate the genetic and environmental contributions to variance for the resting-state DMN functional connectivity. About 9-41% of the variance in functional connectivity between the DMN nodes was attributed to genetic contribution with the greatest heritability found for functional connectivity between the posterior cingulate and right inferior parietal nodes (P<0.001). Our data provide new evidence that functional connectivity measures from the intrinsic DMN derived from task-based fMRI datasets are under genetic control and have the potential to serve as endophenotypes for genetically predisposed psychiatric and neurological disorders.
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Thalamic volume and thalamo-cortical white matter tracts correlate with motor and verbal memory performance.
Neuroimage
PUBLISHED: 01-05-2014
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Cognitive testing and diffusion tensor imaging data from 121 normal subjects were combined to investigate the relationship between thalamic connectivity and cognitive performance. Thalamic regions were segmented based on their cortical connectivity, and regions for both ipsilateral and contralateral thalamocortical connections were identified. White matter tracts corresponding to these regions were identified and the mean fractional anisotropy, and axial and radial diffusivities within each tract were measured. Motor task performance correlated with radial diffusivity in the dominant thalamo-precentral tract. Verbal memory corresponded with the thalamic volume connected to the left temporal lobe. These data support the use of diffusion tractography to identify functionally important regions within the thalamus. Our findings provide the first robust correlation between thalamic volumes and tract characteristics with cognitive performance data in normal subjects.
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Cerebral responses to innocuous somatic pressure stimulation following aerobic exercise rehabilitation in chronic pain patients: a functional magnetic resonance imaging study.
Int J Gen Med
PUBLISHED: 01-01-2014
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The purpose of this research was to assess the functional brain activity and perceptual rating of innocuous somatic pressure stimulation before and after exercise rehabilitation in patients with chronic pain.
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Tractography of the brainstem in major depressive disorder using diffusion tensor imaging.
PLoS ONE
PUBLISHED: 01-01-2014
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The brainstem is the main region that innervates neurotransmitter release to the Hypothalamic-Pituitary Adrenal (HPA) axis and fronto-limbic circuits, two key brain circuits found to be dysfunctional in Major Depressive Disorder (MDD). However, the brainstem's role in MDD has only been evaluated in limited reports. Using Diffusion Tensor Imaging (DTI), we investigated whether major brainstem white matter tracts that relate to these two circuits differ in MDD patients compared to healthy controls.
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Impact of early vs. late childhood early life stress on brain morphometrics.
Brain Imaging Behav
PUBLISHED: 12-18-2013
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Previous studies of early life trauma suggest that in addition to its emotional impact, exposure to early life stress (ELS) is associated with alterations in brain structure. However, little attention has been devoted to the relationship between emotional processing and brain integrity as a function of age of ELS onset. In the present study we examined whether ELS onset in older ages of youth rather than younger ages is associated with smaller limbic and basal ganglia volumes as measured by magnetic resonance imaging (MRI). We hypothesized that later age of manifestation during youth is associated with smaller volumetric morphology in limbic and basal ganglia volumes in adulthood. A total of 173 individuals were divided into three groups based on the age of self-reported ELS. The three groups included individuals only experiencing early childhood ELS (1 month-7 years, n = 38), those only experiencing later childhood ELS (8 years -17 years, n = 59), and those who have not experienced ELS (n = 76). Anterior cingulate cortex (ACC), hippocampus, amygdala, insula and caudate volumes were measured using a T1-weighted MRI. Analyses confirmed that later childhood ELS was associated with volumetric reductions in the ACC and insula volumes, while ELS experienced between the ages of 1 month and 7 years was not associated with lower brain volumes in these regions. The results may reflect the influence of more fully developed emotional processing of ELS on the developing brain and reinforce a body of research implicating both the ACC and insula in neuropsychiatric disorders and emotional regulation.
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Neuroplasticity in the adaptation to prosthodontic treatment.
J Orofac Pain
PUBLISHED: 07-25-2013
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To investigate cerebral cortical changes by using functional magnetic resonance imaging (fMRI) after denture renewal and to test how these relate to prosthodontic treatment adaptability as measured by chewing efficiency and maximum bite force.
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Body mass index and brain structure in healthy children and adolescents.
Int. J. Neurosci.
PUBLISHED: 07-19-2013
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Obesity is associated with cognitive dysfunction in children and adolescents, although the mechanisms underlying these deficits remain unclear. This study examined the associations between body mass index (BMI) and regional gray matter volume and white matter integrity in 120 healthy children and adolescents (6-18 years of age) who underwent magnetic resonance and diffusion tensor imaging. Bonferroni-corrected partial correlation analyses controlling for demographic and clinical characteristics revealed significant inverse associations between demographically standardized BMI values and gray matter volume of frontal (r = -0.31) and limbic (r = -0.35) brain regions. No such pattern emerged for fractional anisotropy of white matter tracts. Subsequent hierarchical regression analyses indicated that the relationship between standardized BMI and structural gray and white matter brain indices did not vary with age. These findings suggest that obesity in children and adolescents is associated with decreased volume of frontal and limbic cerebral gray matter regions. Further research is much needed to better elucidate possible brain-based mechanisms for cognitive dysfunction associated with obesity.
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Chronic effects of dietary vitamin D deficiency without increased calcium supplementation on the progression of experimental polycystic kidney disease.
Am. J. Physiol. Renal Physiol.
PUBLISHED: 05-22-2013
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Increasing evidence indicates that vitamin D deficiency exacerbates chronic kidney injury, but its effects on renal enlargement in polycystic kidney disease (PKD) are not known. In this study, male Lewis polycystic kidney disease (LPK) rats received a normal diet (ND; AIN-93G) supplemented with or without cholecalciferol (vitamin D-deficient diet, VDD; both 0.5% calcium), commenced at either postnatal week 3 (until weeks 10-20; study 1) or from week 10 (until week 20; study 2). Levels of 25-hydroxy vitamin D were reduced in groups receiving the VDD (12 ± 1 nmol/l vs. 116 ± 5 in ND; P < 0.001). In study 1, food intake and weight gain increased by ?25% in LPK rats receiving the VDD ad libitum, and at week 20 this was associated with a mild reduction in the corrected serum calcium (SCa(2+), 7.4%) and TKW:BW ratio (8.8%), and exacerbation of proteinuria (87%) and hypertension (19%; all P < 0.05 vs. ND). When LPK rats were pair-fed for weeks 3-10, there was a further reduction in the SCa(2+) (25%) and TKW:BW ratio (22%) in the VDD group (P < 0.05 vs. ND). In study 2, the VDD did not alter food intake and body weight, reduced SCa(2+) (7.7%), worsened proteinuria (41.9%), interstitial monocyte accumulation (26.4%), renal dysfunction (21.4%), and cardiac enlargement (13.2%, all P < 0.05), but there was a trend for a reduction in the TKW:BW ratio (13%, P = 0.09). These data suggest that chronic vitamin D deficiency has adverse long-term actions on proteinuria, interstitial inflammation, renal function, and cardiovascular disease in PKD, and these negate its mild inhibitory effect on kidney enlargement.
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Higher education is an age-independent predictor of white matter integrity and cognitive control in late adolescence.
Dev Sci
PUBLISHED: 04-10-2013
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Socioeconomic status is an important predictor of cognitive development and academic achievement. Late adolescence provides a unique opportunity to study how the attainment of socioeconomic status (in the form of years of education) relates to cognitive and neural development, during a time when age-related cognitive and neural development is ongoing. During late adolescence it is possible to disambiguate age- and education-related effects on the development of these processes. Here we assessed the degree to which higher educational attainment was related to performance on a cognitive control task, controlling for age. We then used diffusion tensor imaging (DTI) to assess the degree to which white matter microstructure might mediate this relationship. When covarying age, significant associations were found between educational attainment and fractional anisotropy (FA) in the superior longitudinal fasciculus (SLF) and cingulum bundle (CB). Further, when covarying age, FA in these regions was associated with cognitive control. Finally, mediation analyses revealed that the age-independent association between educational attainment and cognitive control was completely accounted for by FA in these regions. The uncinate fasciculus, a late-myelinated control region not implicated in cognitive control, did not mediate this effect.
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The genetic and neuroanatomical basis of social dysfunction: Lessons from neurofibromatosis type 1.
Hum Brain Mapp
PUBLISHED: 02-04-2013
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Neurofibromatosis type 1 (NF1) is a common genetic condition associated with cognitive and social dysfunction as well as abnormal brain structure. The pathophysiology underlying social dysfunction in NF1 is poorly understood. Here, we investigate for the first time whether there is a broad deficit of social cognition in NF1 and explore the neural correlates for these deficits. Twenty-nine adults with NF1 and 30 controls were administered an ecologically based test of social cognition, The Awareness of Social Inference Test (TASIT), to identify deficits in emotion recognition and sarcasm detection. We employed voxel-based morphometry in a subset of NF1 patients (n = 16) and 16 additional controls to examine the neural correlates of these deficits. Results indicated that adults with NF1 were impaired in their ability to understand paradoxical sarcasm and their capacity to recognize emotion, particularly anger. TASIT performance was not associated with measures of attention, visuospatial skills or executive function. Relative to controls, gray matter (GM) volume within the right superior temporal gyrus (STG) was decreased, after controlling for total brain volume. Decreased volume in this region was significantly associated with social cognitive deficits in adults with NF1. We conclude that patients with NF1 are at high risk for a social cognitive deficit and provide evidence for a neuroanatomical basis for this deficit; GM volumetric reductions in the right STG. These findings improve our understanding of the nature of social interaction impairments in NF1 and add to the growing body of literature indicating the STG as a critical brain region for social cognition. Hum Brain Mapp, 2013. © 2013 Wiley Periodicals, Inc.
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Brain imaging predictors and the international study to predict optimized treatment for depression: study protocol for a randomized controlled trial.
Trials
PUBLISHED: 02-04-2013
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Approximately 50% of patients with major depressive disorder (MDD) do not respond optimally to antidepressant treatments. Given this is a large proportion of the patient population, pretreatment tests that predict which patients will respond to which types of treatment could save time, money and patient burden. Brain imaging offers a means to identify treatment predictors that are grounded in the neurobiology of the treatment and the pathophysiology of MDD.
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Widespread reductions in gray matter volume in depression.
Neuroimage Clin
PUBLISHED: 01-01-2013
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Abnormalities in functional limbic-anterior cingulate-prefrontal circuits associated with emotional reactivity, evaluation and regulation have been implicated in the pathophysiology of major depressive disorder (MDD). However, existing knowledge about structural alterations in depression is equivocal and based on cohorts of limited sample size. This study used voxel-based morphometry (VBM) and surface-based cortical thickness to investigate the structure of these circuits in a large and well-characterized patient cohort with MDD. Non-geriatric MDD outpatients (n = 102) and age- and gender-matched healthy control participants (n = 34) provided T1-weighted magnetic resonance imaging data during their baseline visit as part of the International Study to Predict Optimized Treatment for Depression. Whole-brain VBM volumetric and surface-based cortical thickness assessments were performed voxel-wise and compared (at p < 0.05 corrected for multiple comparisons) between the MDD and control groups. MDD participants had reduced gray matter volume in the anterior cingulate cortex, regions of the prefrontal circuits, including dorsolateral and dorsomedial prefrontal cortices, and lateral and medial orbitofrontal cortices, but not in limbic regions. Additional reductions were observed cortically in the posterior temporal and parieto-occipital cortices and, subcortically in the basal ganglia and cerebellum. Focal cortical thinning in the medial orbitofrontal cortex was also observed for the MDD group. These alterations in volume and cortical thickness were not associated with severity of depressive symptoms. The findings demonstrate that widespread gray matter structural abnormalities are present in a well-powered study of patients with depression. The patterns of gray matter loss correspond to the same brain functional network regions that were previously established to be abnormal in MDD, which may support an underlying structural abnormality for these circuits.
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Early exposure to traumatic stressors impairs emotional brain circuitry.
PLoS ONE
PUBLISHED: 01-01-2013
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Exposure to early life trauma (ELT) is known to have a profound impact on mental development, leading to a higher risk for depression and anxiety. Our aim was to use multiple structural imaging methods to systematically investigate how traumatic stressors early in life impact the emotional brain circuits, typically found impaired with clinical diagnosis of depression and anxiety, across the lifespan in an otherwise healthy cohort. MRI data and self-reported histories of ELT from 352 healthy individuals screened for no psychiatric disorders were analyzed in this study. The volume and cortical thickness of the limbic and cingulate regions were assessed for all participants. A large subset of the cohort also had diffusion tensor imaging data, which was used to quantify white matter structural integrity of these regions. We found a significantly smaller amygdala volume and cortical thickness in the rostral anterior cingulate cortex associated with higher ELT exposure only for the adolescence group. White matter integrity of these regions was not affected. These findings demonstrate that exposure to early life trauma is associated with alterations in the gray matter of cingulate-limbic regions during adolescence in an otherwise healthy sample. These findings are interesting in the context that the affected regions are central neuroanatomical components in the psychopathology of depression, and adolescence is a peak period for risk and onset of the disorder.
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GSK3B and MAPT polymorphisms are associated with grey matter and intracranial volume in healthy individuals.
PLoS ONE
PUBLISHED: 01-01-2013
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The microtubule-associated protein tau gene (MAPT) codes for a protein that plays an integral role in stabilisation of microtubules and axonal transport in neurons. As well as its role in susceptibility to neurodegeneration, previous studies have found an association between the MAPT haplotype and intracranial volume and regional grey matter volumes in healthy adults. The glycogen synthase kinase-3? gene (GSK3B) codes for a serine/threonine kinase that phosphorylates various proteins, including tau, and has also been associated with risk for neurodegenerative disorders and schizophrenia. We examined the effects of MAPT and two functional promoter polymorphisms in GSK3B (rs3755557 and rs334558) on total grey matter and intracranial volume in three independent cohorts totaling 776 neurologically healthy individuals. In vitro analyses revealed a significant effect of rs3755557 on gene expression, and altered binding of at least two transcription factors, Octamer transcription factor 1 (Oct-1) and Pre-B-cell leukemia transcription factor 1 (Pbx-1), to the GSK3B promoter. Meta-analysis across the three cohorts revealed a significant effect of rs3755557 on total grey matter volume (summary B?=?0.082, 95% confidence interval?=?0.037-0.128) and intracranial volume (summary B?=?0.113, 95% confidence interval?=?0.082-0.144). No significant effect was observed for MAPT H1/H2 diplotype or GSK3B rs334558 on total grey matter or intracranial volume. Our genetic and biochemical analyses have identified a role for GSK3B in brain development, which could have important aetiological implications for neurodegenerative and neurodevelopmental disorders.
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Testing the white matter retrogenesis hypothesis of cognitive aging.
Neurobiol. Aging
PUBLISHED: 05-16-2011
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The retrogenesis hypothesis postulates that late-myelinated white matter fibers are most vulnerable to age- and disease-related degeneration, which in turn mediate cognitive decline. While recent evidence supports this hypothesis in the context of Alzheimers disease, it has not been tested systematically in normal cognitive aging. In the current study, we examined the retrogenesis hypothesis in a group (n = 282) of cognitively normal individuals, ranging in age from 7 to 87 years, from the Brain Resource International Database. Participants were evaluated with a comprehensive neuropsychological battery and were imaged with diffusion tensor imaging. Fractional anisotropy (FA), radial diffusivity (RD), and axial diffusivity (DA), measures of white matter coherence, were computed in 2 prototypical early-myelinated fiber tracts (posterior limb of the internal capsule, cerebral peduncles) and 2 prototypical late-myelinated fiber tracts (superior longitudinal fasciculus, inferior longitudinal fasciculus) chosen to parallel previous studies; mean summary values were also computed for other early- and late-myelinated fiber tracts. We examined age-associated differences in FA, RD, and DA in the developmental trajectory (ages 7-30 years) and degenerative trajectory (ages 31-87 years), and tested whether the measures of white matter coherence mediated age-related cognitive decline in the older group. FA and DA values were greater for early-myelinated fibers than for late-myelinated fibers, and RD values were lower for early-myelinated than late-myelinated fibers. There were age-associated differences in FA, RD, and DA across early- and late-myelinated fiber tracts in the younger group, but the magnitude of differences did not vary as a function of early or late myelinating status. FA and RD in most fiber tracts showed reliable age-associated differences in the older age group, but the magnitudes were greatest for the late-myelinated tract summary measure, inferior longitudinal fasciculus (late fiber tract), and cerebral peduncles (early fiber tract). Finally, FA in the inferior longitudinal fasciculus and cerebral peduncles and RD in the cerebral peduncles mediated age-associated differences in an executive functioning factor. Taken together, the findings highlight the importance of white matter coherence in cognitive aging and provide some, but not complete, support for the white matter retrogenesis hypothesis in normal cognitive aging.
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Regional heterogeneity in limbic maturational changes: evidence from integrating cortical thickness, volumetric and diffusion tensor imaging measures.
Neuroimage
PUBLISHED: 01-09-2011
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Magnetic resonance imaging (MRI) studies of structural brain development have suggested that the limbic system is relatively preserved in comparison to other brain regions with healthy aging. The goal of this study was to systematically investigate age-related changes of the limbic system using measures of cortical thickness, volumetric and diffusion characteristics. We also investigated if the "relative preservation" concept is consistent across the individual sub-regions of the limbic system. T1 weighted structural MRI and Diffusion Tensor Imaging data from 476 healthy participants from the Brain Resource International Database was used for this study. Age-related changes in grey matter (GM)/white matter (WM) volume, cortical thickness, diffusional characteristics for the pericortical WM and for the fiber tracts associated with the limbic regions were quantified. A regional variability in the aging patterns across the limbic system was present. Four important patterns of age-related changes were highlighted for the limbic sub-regions: 1. early maturation of GM with late loss in the hippocampus and amygdala; 2. an extreme pattern of GM preservation in the entorhinal cortex; 3. a flat pattern of reduced GM loss in the anterior cingulate and the parahippocampus and; 4. accelerated GM loss in the isthmus and posterior cingulate. The GM volumetric data and cortical thickness measures proved to be internally consistent, while the diffusional measures provided complementary data that seem consistent with the GM trends identified. This heterogeneity can be hypothesized to be associated with age-related changes of cognitive function specialized for that region and direct connections to the other brain regions sub-serving these functions.
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Obesity is associated with reduced white matter integrity in otherwise healthy adults.
Obesity (Silver Spring)
PUBLISHED: 12-23-2010
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Existing work demonstrates that obesity is independently associated with cognitive dysfunction and macrostructural brain changes; however, little is known about the association between obesity and white matter (WM) integrity. We explore this relationship in a large cohort of otherwise healthy subjects. The present study classified 103 adult participants from the Brain Resource International Database between 21 and 86 years of age without history of neurological, medical, or psychiatric illness according to BMI (normal weight, overweight, obese) and subjected them to diffusion tensor imaging (DTI). Resulting fractional anisotropy (FA) indexes for the corpus callosum and fornix were examined in relation to BMI and age in a multiple regression framework. Results indicated that increasing BMI was independently associated with lower FA in the genu, splenium, and fornix, and a BMI × age interaction emerged for FA in the splenium and body of the corpus callosum. When categorized, obese persons demonstrated lower FA than normal and overweight persons for all WM indexes, but no FA differences emerged between overweight and normal persons. Results indicate both a direct association between obesity and reduced WM tract integrity and an interaction between obesity and aging processes on certain WM tracts in otherwise healthy adults. While such findings suggest a possible role for adiposity in WM dysfunction and associated cognitive deficits, prospective studies are needed to clarify the nature of these relationships and elucidate underlying mechanisms.
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Loss of white matter integrity in major depressive disorder: evidence using tract-based spatial statistical analysis of diffusion tensor imaging.
Hum Brain Mapp
PUBLISHED: 07-05-2010
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White matter (WM) has been shown to be affected in elderly patients with major depressive disorders (MDD). There is only limited evidence of WM structural abnormalities in nongeriatric MDD patients. This study investigates WM microstructural integrity in nongeriatric MDD patients recruited as part of the International Study to Predict Optimized Treatment in Depression clinical trial and establishes the validity of diffusion tensor imaging measures for the investigation of depression. Baseline diffusion tensor imaging data from 29 nongeriatric MDD participants (11 with melancholia) and 39 healthy control participants were used in this analysis. We performed tract-based spatial statistics analyses to evaluate WM microstructural integrity (1) between all healthy controls and all MDD participants, (2) between melancholic and nonmelancholic MDD participants, and (3) between each subgroup (melancholic and nonmelancholic) and controls. Significant WM integrity deficits were seen only for the melancholic MDD participants compared with controls. Compared with controls, melancholic participants showed an average reduction of 7.8% in fractional anisotropy over WM regions associated with the limbic system, dorsolateral prefrontal cortex, thalamic projection fibers, corpus callosum, and other association fibers. These fractional anisotropy deficits were also associated with decreased axial and increased radial diffusivity in these WM regions, suggesting a pattern of decreased myelination or other degeneration change. Our findings of WM structural abnormalities associated with the limbic system, the frontal cortex, and the thalamus support the prevailing theory of limbic-dorsolateral prefrontal cortex-thalamic dysfunction in depression. Our results also suggest that these deficits are most prominent in the melancholic subtype of MDD.
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Limbic dysregulation is associated with lowered heart rate variability and increased trait anxiety in healthy adults.
Hum Brain Mapp
PUBLISHED: 02-28-2009
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We tested whether dynamic interaction between limbic regions supports a control systems model of excitatory and inhibitory components of a negative feedback loop, and whether dysregulation of those dynamics might correlate with trait differences in anxiety and their cardiac characteristics among healthy adults.
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Using standardized fMRI protocols to identify patterns of prefrontal circuit dysregulation that are common and specific to cognitive and emotional tasks in major depressive disorder: first wave results from the iSPOT-D study.
Neuropsychopharmacology
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Functional neuroimaging studies have implicated dysregulation of prefrontal circuits in major depressive disorder (MDD), and these circuits are a viable target for predicting treatment outcomes. However, because of the heterogeneity of tasks and samples used in studies to date, it is unclear whether the central dysfunction is one of prefrontal hyperreactivity or hyporeactivity. We used a standardized battery of tasks and protocols for functional magnetic resonance imaging, to identify the common vs the specific prefrontal circuits engaged by these tasks in the same 30 outpatients with MDD compared with 30 matched, healthy control participants, recruited as part of the International Study to Predict Optimized Treatment in Depression (iSPOT-D). Reflecting cognitive neuroscience theory and established evidence, the battery included cognitive tasks designed to assess functions of selective attention, sustained attention-working memory and response inhibition, and emotion tasks to assess explicit conscious and implicit nonconscious viewing of facial emotion. MDD participants were distinguished by a distinctive biosignature of: hypoactivation of the dorsolateral prefrontal cortex during working memory updating and during conscious negative emotion processing; hyperactivation of the dorsomedial prefrontal cortex during working memory and response inhibition cognitive tasks and hypoactivation of the dorsomedial prefrontal during conscious processing of positive emotion. These results show that the use of standardized tasks in the same participants provides a way to tease out prefrontal circuitry dysfunction related to cognitive and emotional functions, and not to methodological or sample variations. These findings provide the frame of reference for identifying prefrontal biomarker predictors of treatment outcomes in MDD.
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Hippocampal volume varies with educational attainment across the life-span.
Front Hum Neurosci
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Socioeconomic disparities-and particularly differences in educational attainment-are associated with remarkable differences in cognition and behavior across the life-span. Decreased educational attainment has been linked to increased exposure to life stressors, which in turn have been associated with structural differences in the hippocampus and the amygdala. However, the degree to which educational attainment is directly associated with anatomical differences in these structures remains unclear. Recent studies in children have found socioeconomic differences in regional brain volume in the hippocampus and amygdala across childhood and adolescence. Here we expand on this work, by investigating whether disparities in hippocampal and amygdala volume persist across the life-span. In a sample of 275 individuals from the BRAINnet Foundation database ranging in age from 17 to 87, we found that socioeconomic status (SES), as operationalized by years of educational attainment, moderates the effect of age on hippocampal volume. Specifically, hippocampal volume tended to markedly decrease with age among less educated individuals, whereas age-related reductions in hippocampal volume were less pronounced among more highly educated individuals. No such effects were found for amygdala volume. Possible mechanisms by which education may buffer age-related effects on hippocampal volume are discussed.
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The TWIN-E project in emotional wellbeing: study protocol and preliminary heritability results across four MRI and DTI measures.
Twin Res Hum Genet
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Despite the significant advancements being made in the neurogenetics for mental health, the identification and validation of potential endophenotype markers of risk and resilience remain to be confirmed. The TWIN-E study (The Twin study in Wellbeing using Integrative Neuroscience of Emotion) aims to validate endophenotype markers of mental health across cognitive, brain, and autonomic measures by testing the heritability, clinical plausibility, and reliability of each of these measures in a large adult twin cohort. The specific gene and environmental mechanisms that moderate prospective links between endophenotype-phenotype markers and the final outcome of wellbeing will also be identified. TWIN-E is a national prospective study with three phases: I) baseline testing on a battery of online questionnaires and cognitive tasks, and EEG, MRI, and autonomic testing; II) 12-month follow-up testing on the online assessments; and III) randomized controlled trial of brain training. Minimum target numbers include 1,500 male/female twins (18-65 years) for the online assessments (Phase I and II), 300 twins for the EEG testing component, and 244 twins for the MRI testing component. For Phase III, each twin out of the pair will be randomized to either the treatment or waitlist control group to test the effects of brain training on mental health over a 30-day period, and to confirm the gene-environment and endophenotype contributions to treatment response. Preliminary heritability results are provided for the first 50% of the MRI subgroup (n = 142) for the grey matter volume, thickness, and surface area measures, and white matter diffuse tensor imaging fractional anisotropy.
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Mapping inter-regional connectivity of the entire cortex to characterize major depressive disorder: a whole-brain diffusion tensor imaging tractography study.
Neuroreport
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Diffusion tensor imaging (DTI) can be used to study the organization of brain white matter noninvasively. The aim of this study was to present a proof of concept for integrating DTI with high-resolution anatomical (T1) images to map and assess inter-regional connectivity across the entire cortex in a cohort of healthy participants and compared with patients with major depressive disorder. We used MRI data of 23 patients and 23 matched controls, assessed as part of baseline testing in the International Study to Predict Optimized Treatment in Depression (iSPOT-D). Freesurfer was used to analyze the T1 images to automatically label 35 gyral-based areas for each hemisphere. DTI tractography was performed to parcellate intercortical tracts using each of these areas in seed-target combinations. We quantified fractional anisotropy, number-of-fiber connections, and fiber path length for each DTI connection, with the goal of identifying the best measure or combination of measures to characterize major depression. The best classification accuracy for the individual measures was achieved using the number-of-fibers data, whereas the combination model provided a slight improvement. The most discriminant features between the two groups were for white matter associated with the limbic, frontal, and thalamic projection fibers and as part of cortical connections between the left inferior temporal and the postcentral cortex; the left parstriangularis and the left superior frontal; the left cuneus and the corpus callosum; the left lingual and the right lateral occipital, the right superior parietal and the right superior temporal cortices; and the right inferior parietal and the right insula and postcentral cortices.
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JoVE Visualize is a tool created to match the last 5 years of PubMed publications to methods in JoVE's video library.

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In developing our video relationships, we compare around 5 million PubMed articles to our library of over 4,500 methods videos. In some cases the language used in the PubMed abstracts makes matching that content to a JoVE video difficult. In other cases, there happens not to be any content in our video library that is relevant to the topic of a given abstract. In these cases, our algorithms are trying their best to display videos with relevant content, which can sometimes result in matched videos with only a slight relation.