New resting-state fMRI related studies at PubMed

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Altered gray matter volume and disrupted functional connectivity of dorsolateral prefrontal cortex in men with heroin dependence.

Thu, 10/04/2018 - 14:40
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Altered gray matter volume and disrupted functional connectivity of dorsolateral prefrontal cortex in men with heroin dependence.

Psychiatry Clin Neurosci. 2018 Jun;72(6):435-444

Authors: Lin HC, Wang PW, Wu HC, Ko CH, Yang YH, Yen CF

Abstract
AIM: Chronic heroin use can cause various neuropathological characteristics that may compromise brain function. The present study evaluated the alteration of gray matter volume (GMV) and its resting-state functional connectivity (rsFC) over the dorsolateral prefrontal cortex (DLPFC) among male heroin users.
METHODS: Thirty heroin-dependent men undergoing methadone maintenance therapy and 30 educational-level- and age-matched male controls were recruited for this study. To assess their GMV and rsFC, the participants were evaluated using spoiled gradient echo and gradient-recalled echo planar imaging sequences with a 3-Tesla General Electric MR scanner under resting state.
RESULTS: The heroin-dependent men showed lower GMV over the right DLPFC in comparison with the controls. Further evaluation of the rsFC of the right DLPFC revealed a marked decrease in interhemispheric DLPFC connectivity among those with heroin dependence under control of head movement and GMV of the right DLPFC.
CONCLUSION: Although the mechanism remains unclear, the present study shows that chronic heroin use is associated with alteration of morphology as well as rsFC over the right DLPFC. As the DLPFC plays an imperative role in various domains of cognitive function, service providers for heroin users should consider the impacts of possible DLPFC-related cognitive deficits on treatment effectiveness.

PMID: 29582514 [PubMed - indexed for MEDLINE]

resting state fMRI; +18 new citations

Wed, 10/03/2018 - 12:55

18 new pubmed citations were retrieved for your search. Click on the search hyperlink below to display the complete search results:

resting state fMRI

These pubmed results were generated on 2018/10/03

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Abnormal cerebellum-DMN regions connectivity in unmedicated bipolar II disorder.

Wed, 10/03/2018 - 00:40

Abnormal cerebellum-DMN regions connectivity in unmedicated bipolar II disorder.

J Affect Disord. 2018 Sep 21;243:441-447

Authors: Chen G, Zhao L, Jia Y, Zhong S, Chen F, Luo X, Qiu S, Lai S, Qi Z, Huang L, Wang Y

Abstract
OBJECTIVE: Bipolar disorder (BD) is a common psychiatric disease. Previous studies have found abnormalities in structural and functional brain connectivity in BD patients. However, few studies have focused on the functional connectivity (FC) of the cerebellum and its sub-regions in patients with BD. The present study aimed to examine the FC of cerebellum-default mode network (DMN) regions in patients with BD II.
METHOD: Ninety patients with unmedicated BD II depression and 100 healthy controls (HCs) underwent resting-state functional magnetic resonance imaging. We selected three pairs of subregions of the cerebellum that are DMN-related (the bilateral Crus I, Crus II, and lobule IX) as seed regions and calculated the whole brain FC for each subregion.
RESULTS: Compared with the HCs, the patients with BD II depression showed increased connectivity between the right Crus I and bilateral precuneus and decreased connectivity between the left Crus II and bilateral medial prefrontal cortex (mPFC) and between the left Crus II and right medial frontal gyrus (MFG). There was no significant difference in the whole FC of the left Crus I and bilateral lobule IX between the BD II depression group and the HCs group.
LIMITATIONS: This study was cross-sectional and did not examine data from euthymic BD patients.
CONCLUSIONS: The findings showed impaired FC of cerebellum-DMN regions in BD; partial FC between the Crus I and precuneus and the Crus II and prefrontal cortex suggests the importance of abnormal cerebellum-DMN regions FC in the pathophysiology of BD.

PMID: 30273882 [PubMed - as supplied by publisher]

Neural correlates of developing theory of mind competence in early childhood.

Wed, 10/03/2018 - 00:40

Neural correlates of developing theory of mind competence in early childhood.

Neuroimage. 2018 Sep 28;:

Authors: Xiao Y, Geng F, Riggins T, Chen G, Redcay E

Abstract
Theory of mind (ToM) encompasses a range of abilities that show different developmental time courses. However, relatively little work has examined the neural correlates of ToM during early childhood. In this study, we investigated the neural correlates of ToM in typically developing children aged 4-8 years using resting-state functional magnetic resonance imaging. We calculated whole brain functional connectivity with the right temporo-parietal junction (RTPJ), a core region involved in ToM, and examined its relation to children's early, basic, and advanced components of ToM competence assessed by a parent-report measure. Total ToM and both basic and advanced ToM components, but not early, consistently showed a positive correlation with connectivity between RTPJ and posterior cingulate cortex/precuneus; advanced ToM was also correlated with RTPJ to left TPJ connectivity. However, early and advanced ToM components showed negative correlation with the right inferior/superior parietal lobe, suggesting that RTPJ network differentiation is also related to ToM abilities. We confirmed and extended these results using a Bayesian modeling approach demonstrating significant relations between multiple nodes of the mentalizing network and ToM abilities, with no evidence for differences in relations between ToM components. Our data provide new insights into the neural correlates of multiple aspects of ToM in early childhood and may have implications for both typical and atypical development of ToM.

PMID: 30273714 [PubMed - as supplied by publisher]

Mesolimbic connectivity signatures of impulsivity and BMI in early adolescence.

Wed, 10/03/2018 - 00:40

Mesolimbic connectivity signatures of impulsivity and BMI in early adolescence.

Appetite. 2018 Sep 28;:

Authors: Sharkey RJ, Bourque J, Larcher K, Misic B, Zhang Y, Altinkaya A, Sadikot A, Conrod P, Evans AC, Garavan H, Leyton M, Séguin JR, Pihl R, Dagher A

Abstract
Across age groups, differences in connectivity of the mesolimbic and the prefrontal cortex co-vary with trait impulsivity and sensation-seeking. Impulsivity and sensation-seeking are also known to increase during early adolescence as maturation of subcortical structures outpaces that of the prefrontal cortex. While an imbalance between the striatum and prefrontal cortex is considered a normal developmental process, higher levels of adolescent impulsivity and sensation-seeking are associated with an increased risk for diverse problems, including obesity. To determine how the relationship between sensation-seeking, impulsivity and body mass index (BMI) is related to shared neural correlates we measured their relationships with the connectivity of nuclei in the striatum and dopaminergic midbrain in young adolescents. Data were collected from 116 children between the ages of 12 and 14, and included resting state functional magnetic resonance imaging, personality measures from the Substance Use Risk Profile Scale, and BMI Z-score for age. The shared variance for the connectivity of regions of interest in the substantia nigra, ventral tegmental area, ventral striatum and sub-thalamic nucleus, personality measures and BMI Z-score for age, were analyzed using partial least squares correlation. This analysis identified a single significant striato-limbic network that was connected with the substatia nigra, ventral tegmental area and sub-thalamic nuclei (p = 0.002). Connectivity within this network which included the hippocampi, amygdalae, parahippocampal gyri and the regions of interest, correlated positively with impulsivity and BMI Z-score for age and negatively with sensation-seeking. Together, these findings emphasize that, in addition to the well-established role that frontostriatal circuits play in the development of adolescent personality traits, connectivity of limbic regions with the striatum and midbrain also impact impulsivity, sensation-seeking and BMI Z-score in adolescents.

PMID: 30273626 [PubMed - as supplied by publisher]

Focal application of accelerated iTBS results in global changes in graph measures.

Wed, 10/03/2018 - 00:40

Focal application of accelerated iTBS results in global changes in graph measures.

Hum Brain Mapp. 2018 Oct 01;:

Authors: Klooster DCW, Franklin SL, Besseling RMH, Jansen JFA, Caeyenberghs K, Duprat R, Aldenkamp AP, de Louw AJA, Boon PAJM, Baeken C

Abstract
Graph analysis was used to study the effects of accelerated intermittent theta burst stimulation (aiTBS) on the brain's network topology in medication-resistant depressed patients. Anatomical and resting-state functional MRI (rs-fMRI) was recorded at baseline and after sham and verum stimulation. Depression severity was assessed using the Hamilton Depression Rating Scale (HDRS). Using various graph measures, the different effects of sham and verum aiTBS were calculated. It was also investigated whether changes in graph measures were correlated to clinical responses. Furthermore, by correlating baseline graph measures with the changes in HDRS in terms of percentage, the potential of graph measures as biomarker was studied. Although no differences were observed between the effects of verum and sham stimulation on whole-brain graph measures and changes in graph measures did not correlate with clinical response, the baseline values of clustering coefficient and global efficiency showed to be predictive of the clinical response to verum aiTBS. Nodal effects were found throughout the whole brain. The distribution of these effects could not be linked to the strength of the functional connectivity between the stimulation site and the node. This study showed that the effects of aiTBS on graph measures distribute beyond the actual stimulation site. However, additional research into the complex interactions between different areas in the brain is necessary to understand the effects of aiTBS in more detail.

PMID: 30273448 [PubMed - as supplied by publisher]

A Different Brain: Anomalies of Functional and Structural Connections in Williams Syndrome.

Wed, 10/03/2018 - 00:40

A Different Brain: Anomalies of Functional and Structural Connections in Williams Syndrome.

Front Neurol. 2018;9:721

Authors: Gagliardi C, Arrigoni F, Nordio A, De Luca A, Peruzzo D, Decio A, Leemans A, Borgatti R

Abstract
We describe the results of a functional and structural brain connectivity analysis comparing a homogeneous group of 10 young adults with Williams Syndrome (WS; 3 females, age 20. 7 ± 3.7 years, age range 17.4-28.7 years) to a group of 18 controls of similar age (3 females, age 23.9 ± 4.4 years, age range 16.8-30.2), with the aim to increase knowledge of the structure - function relationship in WS. Subjects underwent a 3T brain MRI exam including anatomical, functional (resting state) and structural (diffusion MRI) sequences. We found convergent anomalies in structural and functional connectivity in the WS group. Altered Fractional Anisotropy (FA) values in parieto-occipital regions were associated with increased connectivity in the antero-posterior pathways linking parieto-occipital with frontal regions. The analysis of resting state data showed altered functional connectivity in the WS group in main brain networks (default mode, executive control and dorsal attention, sensori-motor, fronto-parietal, ventral stream). The combined analysis of functional and structural connectivity displayed a different pattern in the two groups: in controls the highest agreement was found in frontal and visual areas, whereas in WS patients in posterior regions (parieto-occipital and temporal areas). These preliminary findings may reflect an altered "wiring" of the brain in WS, which can be driven by hyper-connectivity of the posterior regions as opposed to disrupted connectivity in the anterior areas, supporting the hypothesis that a different brain (organization) could be associated with a different (organization of) behavior in Williams Syndrome.

PMID: 30271373 [PubMed]

Dynamic functional connectivity analysis reveals decreased variability of the default-mode network in developing autistic brain.

Wed, 10/03/2018 - 00:40
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Dynamic functional connectivity analysis reveals decreased variability of the default-mode network in developing autistic brain.

Autism Res. 2018 Oct 01;:

Authors: He C, Chen Y, Jian T, Chen H, Guo X, Wang J, Wu L, Chen H, Duan X

Abstract
Accumulating neuroimaging evidence suggests that abnormal functional connectivity of the default mode network (DMN) contributes to the social-cognitive deficits of autism spectrum disorder (ASD). Although most previous studies relied on conventional functional connectivity methods, which assume that connectivity patterns remain constant over time, understanding the temporal dynamics of functional connectivity during rest may provide new insights into the dysfunction of the DMN in ASD. In this work, dynamic functional connectivity analysis based on sliding time window correlation was applied to the resting-state functional magnetic resonance imaging data of 28 young children with ASD (age range: 3-7 years) and 29 matched typically developing controls (TD group). In addition, k-means cluster analysis was performed to identify distinct temporal states based on the spatial similarity of each functional connectivity pattern. Compared with the TD group, young children with ASD showed decreased dynamic functional connectivity variance between the posterior cingulate cortex (PCC) and the right precentral gyrus, which is negatively correlated with social motivation and social relating. Cluster analysis revealed significant differences in functional connectivity patterns between the ASD and TD groups in discrete temporal states. Our findings reveal that atypical dynamic interactions between the PCC and sensorimotor cortex are associated with social deficits in ASD. Results also highlight the critical role of PCC in the social-cognitive deficits of ASD and support the concept that understanding the dynamic neural interactions among brain regions can provide insights into functional abnormalities in ASD.
LAY SUMMARY: Social cognitive dysfunction in autism spectrum disorder (ASD) is associated with dysfunction of the default mode network (DMN), a set of brain areas involved in various domains of social processing. We found that decreases in the dynamic functional connectivity variance between the posterior cingulate cortex and the sensorimotor cortex are associated with deficits in social motivation and social relating in young children with ASD. This result suggests that aberrations in the DMN and its dynamic interactions with other networks contribute to atypical integration of information with respect to self and others.

PMID: 30270547 [PubMed - as supplied by publisher]

Aberrant functional connectivity of inhibitory control networks in children with autism spectrum disorder.

Wed, 10/03/2018 - 00:40
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Aberrant functional connectivity of inhibitory control networks in children with autism spectrum disorder.

Autism Res. 2018 Oct 01;:

Authors: Voorhies W, Dajani DR, Vij SG, Shankar S, Turan TO, Uddin LQ

Abstract
Development of inhibitory control is a core component of executive function processes and a key aspect of healthy development. Children with autism spectrum disorder (ASD) show impairments in performance on inhibitory control tasks. Nevertheless, the research on the neural correlates of these impairments is inconclusive. Here, we explore the integrity of inhibitory control networks in children with ASD and typically developing (TD) children using resting state functional Magnetic Resonance Imagaing (MRI). In a large multisite sample, we find evidence for significantly greater functional connectivity (FC) of the right inferior frontal junction (rIFJ) with the posterior cingulate gyrus, and left and right frontal poles in children with ASD compared with TD children. Additionally, TD children show greater FC of rIFJ with the superior parietal lobule (SPL) compared with children with ASD. Furthermore, although higher rIFJ-SPL and rIFJ-IPL FC was related to better inhibitory control behaviors in both ASD and TD children, rIFJ-dACC FC was only associated with inhibitory control behaviors in TD children. These results provide preliminary evidence of differences in intrinsic functional networks supporting inhibitory control in children with ASD, and provide a basis for further exploration of the development of inhibitory control in children with the disorder.
LAY SUMMARY: Inhibitory control is an important process in healthy cognitive development. Behavioral studies suggest that inhibitory control is impaired in autism spectrum disorder (ASD). However, research examining the neural correlates underlying inhibitory control differences in children with ASD is inconclusive. This study reveals differences in functional connectivity of brain networks important for inhibitory control in children with ASD compared with typically developing children. Furthermore, it relates brain network differences to parent-reported inhibitory control behaviors in children with ASD. These findings provide support for the hypothesis that differences in brain connectivity may underlie observable behavioral deficits in inhibitory control in children with the disorder. Autism Res 2018. © 2018 International Society for Autism Research, Wiley Periodicals, Inc.

PMID: 30270514 [PubMed - as supplied by publisher]

Whole-Brain Multimodal Neuroimaging Model Using Serotonin Receptor Maps Explains Non-linear Functional Effects of LSD.

Wed, 10/03/2018 - 00:40
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Whole-Brain Multimodal Neuroimaging Model Using Serotonin Receptor Maps Explains Non-linear Functional Effects of LSD.

Curr Biol. 2018 Sep 25;:

Authors: Deco G, Cruzat J, Cabral J, Knudsen GM, Carhart-Harris RL, Whybrow PC, Logothetis NK, Kringelbach ML

Abstract
Understanding the underlying mechanisms of the human brain in health and disease will require models with necessary and sufficient details to explain how function emerges from the underlying anatomy and is shaped by neuromodulation. Here, we provide such a detailed causal explanation using a whole-brain model integrating multimodal imaging in healthy human participants undergoing manipulation of the serotonin system. Specifically, we combined anatomical data from diffusion magnetic resonance imaging (dMRI) and functional magnetic resonance imaging (fMRI) with neurotransmitter data obtained with positron emission tomography (PET) of the detailed serotonin 2A receptor (5-HT2AR) density map. This allowed us to model the resting state (with and without concurrent music listening) and mechanistically explain the functional effects of 5-HT2AR stimulation with lysergic acid diethylamide (LSD) on healthy participants. The whole-brain model used a dynamical mean-field quantitative description of populations of excitatory and inhibitory neurons as well as the associated synaptic dynamics, where the neuronal gain function of the model is modulated by the 5-HT2AR density. The model identified the causative mechanisms for the non-linear interactions between the neuronal and neurotransmitter system, which are uniquely linked to (1) the underlying anatomical connectivity, (2) the modulation by the specific brainwide distribution of neurotransmitter receptor density, and (3) the non-linear interactions between the two. Taking neuromodulatory activity into account when modeling global brain dynamics will lead to novel insights into human brain function in health and disease and opens exciting possibilities for drug discovery and design in neuropsychiatric disorders.

PMID: 30270185 [PubMed - as supplied by publisher]

Physiological Considerations of Functional Magnetic Resonance Imaging in Animal Models.

Wed, 10/03/2018 - 00:40
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Physiological Considerations of Functional Magnetic Resonance Imaging in Animal Models.

Biol Psychiatry Cogn Neurosci Neuroimaging. 2018 Aug 17;:

Authors: Sumiyoshi A, Keeley RJ, Lu H

Abstract
Characterizing the nature and underlying neurobiological causes of psychiatric and neurological diseases at the circuit and network levels has remained elusive and necessitates the use of robust animal models. Noninvasive functional magnetic resonance imaging allows systems-level insight into disease phenotype in humans and animals alike, and functional neuroimaging represents an ideal platform for translational and reverse-translational research, with common measurements collected across species. Animal neuroimaging allows invasive manipulations and conveniently bypasses many limitations associated with human subjects; however, awake animal imaging introduces its own constraints to reduce motion and limit subjective stress. Anesthetics offer a viable alternative, but the pharmacodynamics, pharmacokinetics, and molecular targets of anesthetics and their effects on physiology, neural activity, and neurovascular coupling must be considered. We discuss the physiological basis of and the influence of anesthetics on neurovascular coupling. We discuss anesthetic use in functional magnetic resonance imaging and focus on an anesthetic protocol developed in our laboratory. Finally, we discuss in detail our most recent work examining the physiological basis of resting-state functional magnetic resonance imaging using this anesthetic regimen and the future directions of animal neuroimaging research. Using animal imaging in combination with cutting-edge in vivo neuromodulatory techniques is essential for causal understanding of brain function in health and disease and offers an exemplary bridge between human and animal research studies.

PMID: 30270095 [PubMed - as supplied by publisher]

[The role of the neurophysiological methods in the assessment of the effectiveness of the rehabilitation of sensorimotor disturbances associated with the lesions of the central nervous system at the spinal cord level].

Wed, 10/03/2018 - 00:40
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[The role of the neurophysiological methods in the assessment of the effectiveness of the rehabilitation of sensorimotor disturbances associated with the lesions of the central nervous system at the spinal cord level].

Vopr Kurortol Fizioter Lech Fiz Kult. 2017 Dec 28;94(6):4-9

Authors: Ekusheva EV, Voitenkov VB, Skripchenko NV, Samoilova IG, Filimonov VA

Abstract
AIM: The objective of the present study was the evaluation and comparison of the effectiveness of the differential approaches to the neurorehabilitation of the somatosensory disturbances in the patients presenting with the spinal cord lesions.
MATERIALS AND METHODS: A total of 68 patients with spinal cord lesions were enrolled in the study, including 38 suffering from vascular myelopathy, 18 with the consequences of extramedullar meningioma surgery, 12 with the sequelae of acute transverse myelitis. The control groups was comprised of were 55 subjects. All the participants of the study underwent rehabilitation which included robotized mechanotherapy, stabilography, neuro-muscular stimulation, kinesiotherapy, physical therapy, ergotherapy, massage, etc. Transcranial magnetic stimulation (TMS) and evaluation of somatosensory evoked potentials (SSEP) were carried out before and after the therapy.
RESULTS: In those patients who received personalized therapy, significant changes of TMS parameters (central motor conduction time at rest and in facilitation probe), but not SSEP ones were registered. Moreover, the patients who had undergone personalized therapy exhibited better clinical results than in the absence of such treatment.
CONCLUSION: The results of the study gave evidence that neurorehabilitation had produced the more pronounced beneficial influence as regards the correction of motor disturbances even though the disturbances of the somatosensory functions proved to be more resistant to therapy. The data obtained suggest that taking into consideration the afferent deficit has to be mandatory for the purpose of planning the neurorehabilitative treatment of the patients suffering from sensorimotor disturbances associated with the lesions of the central nervous system at the spinal cord level. TMS and SSEP have to be utilized as the tools for the objective evaluation of the effectiveness of the neurorehabilitation process in such patients.

PMID: 29388926 [PubMed - indexed for MEDLINE]

Impact of bariatric surgery on neural food processing and cognition: an fMRI study.

Mon, 10/01/2018 - 10:40

Impact of bariatric surgery on neural food processing and cognition: an fMRI study.

BMJ Open. 2018 Sep 28;8(9):e022375

Authors: Schulze M, Sörös P, Vogel W, Münte TF, Müller HHO, Philipsen A

Abstract
INTRODUCTION: The Roux-en-Y gastric bypass (RYGB) is one of the most widely used techniques for bariatric surgery. After RYGB, weight loss up to 50%-70% of excess body weight, improvement of insulin-resistance, changes in food preferences and improvements in cognitive performance have been reported. This protocol describes a longitudinal study of the neural correlates associated with food-processing and cognitive performance in patients with morbid obesity before and after RYGB relative to lean controls.
METHODS AND ANALYSIS: This study is a pre-post case-control experiment. Using functional MRI, the neural responses to food stimuli and a working memory task will be compared between 25 patients with obesity, pre and post RYGB, and a matched, lean control group. Resting state fMRI will be measured to investigate functional brain connectivity. Baseline measurements for both groups will take place 4 weeks prior to RYGB and 12 months after RYGB. The effects of RYGB on peptide tyrosine tyrosine and glucagon-like polypeptide-1 will also be determined.
ETHICS AND DISSEMINATION: The project has received ethical approval by the local medical ethics committee of the Carl-von-Ossietzky University of Oldenburg, Germany (registration: 2017-073). Results will be published in a peer-reviewed journal as original research and on international conferences.
TRIAL REGISTRATION NUMBER: DRKS00012495; Pre-results.

PMID: 30269067 [PubMed - in process]

The neural representation of the association between comorbid drug use disorders and childhood maltreatment.

Mon, 10/01/2018 - 10:40

The neural representation of the association between comorbid drug use disorders and childhood maltreatment.

Drug Alcohol Depend. 2018 Sep 21;192:215-222

Authors: Martins BS, Cáceda R, Cisler JM, Kilts CD, James GA

Abstract
BACKGROUND: Comorbidity of drug use disorders (DUD) with other psychopathology is associated with worse functional and treatment outcomes than DUD alone. The present study sought to identify altered functional neural circuitry underlying DUD comorbidity with other psychiatric disorders, and model the relationship of these alterations to childhood trauma (Childhood Trauma Questionnaire) and negative self-beliefs (Beck Depression Inventory).
METHODS: A sample of adult men and women (mean = 36.8 years) with childhood maltreatment histories (n = 81) was allocated into the following groups based on psychiatric diagnoses and drug use history: no current or past psychiatric disorders (trauma control sample, n = 20), DUD only (n = 22), psychopathology only (n = 20), and DUD comorbid with other psychiatric illness (DCoP, n = 25).
RESULTS: Multiple regression of seed-based resting-state fMRI, controlling for age and sex, identified a functional connection between the right rostral anterior cingulate cortex (rACC) and left temporoparietal junction (TPJ) that was significantly increased in DCoP females, relative to the other clinical and control groups. Within the DCoP female sample, mediation analysis demonstrated that strength of connectivity between the subgenual cingulate cortex and both the right anterior insula and rostral lateral prefrontal cortex significantly mediated the relationship between increasing physical abuse and self-criticism with age as a moderator.
CONCLUSIONS: This study related sex-dependent alterations in functional organization of the prefrontal cortex with DCoP that are, in turn, related to magnitude of negative self-beliefs to childhood trauma exposure. Additionally, DCoP-selective alterations in rACC connectivity suggest that the neural correlates of DCoP do not represent linear additive contributions from two independent disorders.

PMID: 30268937 [PubMed - as supplied by publisher]

Amygdala-orbitofrontal functional connectivity mediates the relationship between sensation seeking and alcohol use among binge-drinking adults.

Mon, 10/01/2018 - 10:40

Amygdala-orbitofrontal functional connectivity mediates the relationship between sensation seeking and alcohol use among binge-drinking adults.

Drug Alcohol Depend. 2018 Sep 18;192:208-214

Authors: Crane NA, Gorka SM, Phan KL, Childs E

Abstract
BACKGROUND: Decreased amygdala-orbitofrontal cortex (OFC) neural functional connectivity (FC) positively predicts alcohol use among adolescents. Low amygdala-OFC FC is also associated with poor emotion regulation, a trait robustly linked to alcohol use. Thus, decreased amygdala-OFC connectivity may represent a risk factor for the development of alcohol use disorder (AUD) via impaired emotion regulation or reward processing. In this study, we examined amygdala-OFC FC among young adult binge drinkers at high risk for AUD. We also tested if amygdala-OFC FC mediates the relationship between externalizing personality traits and alcohol use.
METHODS: Healthy male and female (n = 39) binge drinkers completed a resting state fMRI scan and the Eysenck Impulsive Personality questionnaire. We utilized seed-based connectivity of the left and right amygdala to prefrontal regions as well as mediation analysis.
RESULTS: Individuals with higher weekly alcohol use displayed decreased right amygdala-OFC FC. Furthermore, high trait venturesomeness, but not impulsivness, was associated with decreased right amygdala-OFC FC. Finally, right amygdala-OFC FC mediated the relationship between trait venturesomeness and weekly drinking; individuals with high trait venturesomeness displayed decreased right amygdala-OFC FC, which in turn predicted greater weekly drinking.
CONCLUSIONS: Our findings corroborate and extend the adolescent literature by showing that decreased amygdala-OFC FC is associated with higher alcohol consumption among adults at elevated risk for AUD. This study also demonstrates for the first time that this neural profile reflects a tendency to sensation seeking. In sum, our findings suggest that amygdala-OFC FC may be an objective neural target for alcohol use prevention and intervention.

PMID: 30268936 [PubMed - as supplied by publisher]

Resting state dynamics meets anatomical structure: Temporal multiple kernel learning (tMKL) model.

Sun, 09/30/2018 - 15:40
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Resting state dynamics meets anatomical structure: Temporal multiple kernel learning (tMKL) model.

Neuroimage. 2018 Sep 26;:

Authors: Surampudi SG, Misra J, Deco G, Surampudi RB, Sharma A, Roy D

Abstract
Over the last decade there has been growing interest in understanding the brain activity, in the absence of any task or stimulus, captured by the resting-state functional magnetic resonance imaging (rsfMRI). The resting state patterns have been observed to be exhibiting complex spatio-temporal dynamics and substantial effort has been made to characterize the dynamic functional connectivity (dFC) configurations. However, the dynamics governing the state transitions that the brain undergoes and their relationship to stationary functional connectivity still remains an open problem. One class of approaches attempts to characterize the dynamics in terms of finite number of latent brain states, however, such attempts are yet to amalgamate the underlying anatomical structural connectivity (SC) with the dynamics. Another class of methods links individual dynamic FCs with the underlying SC but does not characterize the temporal evolution of FC. Further, the latent states discovered by previous approaches could not be directly linked to the SC, thereby motivating us to discover the underlying lower-dimensional manifold that represents the temporal structure. In the proposed approach, the discovered manifold is further parameterized as a set of local density distributions, or latent transient states. We propose an innovative method that learns parameters specific to the latent states using a graph-theoretic model (temporal Multiple Kernel Learning, tMKL) that inherently links dynamics to the structure and finally predicts the grand average FC of the test subjects by leveraging a state transition Markov model. The proposed solution does not make strong assumptions about the underlying data and is generally applicable to resting or task data for learning subject-specific state transitions and for successfully characterizing SC-dFC-FC relationship through a unifying framework. Training and testing were done using the rs-fMRI data of 46 healthy participants. tMKL model performs significantly better than the existing models for predicting resting state functional connectivity based on whole-brain dynamic mean-field model (DMF), single diffusion kernel (SDK) model and multiple kernel learning (MKL) model. Further, the learned model was tested on an independent cohort of 100 young, healthy participants from the Human Connectome Project (HCP) and the results establish the generalizability of the proposed solution. More importantly, the model retains sensitivity toward subject-specific anatomy, a unique contribution towards a holistic approach for SC-FC characterization.

PMID: 30267857 [PubMed - as supplied by publisher]

On the pros and cons of using temporal derivatives to assess brain functional connectivity.

Sun, 09/30/2018 - 15:40
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On the pros and cons of using temporal derivatives to assess brain functional connectivity.

Neuroimage. 2018 Sep 26;:

Authors: Ochab JK, Tarnowski W, Nowak MA, Chialvo DR

Abstract
The study of correlations between brain regions is an important chapter of the analysis of large-scale brain spatiotemporal dynamics. In particular, novel methods suited to extract dynamic changes in mutual correlations are needed. Here we scrutinize a recently reported metric dubbed "Multiplication of Temporal Derivatives" (MTD) which is based on the temporal derivative of each time series. The formal comparison of the MTD formula with the Pearson correlation of the derivatives reveals only minor differences, which we find negligible in practice. A comparison with the sliding window Pearson correlation of the raw time series in several stationary and non-stationary set-ups, including a realistic stationary network detection, reveals lower sensitivity of derivatives to low frequency drifts and to autocorrelations but also lower signal-to-noise ratio. It does not indicate any evident mathematical advantages of the proposed metric over commonly used correlation methods.

PMID: 30267855 [PubMed - as supplied by publisher]

Epstein-barr virus-associated encephalitis in a case-series of more than 40 patients.

Sun, 09/30/2018 - 15:40
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Epstein-barr virus-associated encephalitis in a case-series of more than 40 patients.

Wiad Lek. 2018;71(6):1224-1230

Authors: Dyachenko P, Smiianova O, Kurhanskaya V, Oleshko A, Dyachenko A

Abstract
OBJECTIVE: Introduction: Epstein-Barr virus (EBV) infection can present with neurologic manifestations including encephalitis, aseptic meningitis, Guillain-Barre syndrome, and many others. Most reported cases have been in children. Little is known about EBV encephalitis in adults. The aim: To describe the clinical presentations, investigational findings, management and outcome of adult patients with EBV encephalitis.
PATIENTS AND METHODS: Materials and methods: This report conducted a retrospective review of all cases of EBV-associated encephalitis compiled in the Kyiv's referral hospital from January 2016 to December 2017.
RESULTS: Review: Out of 226 adult patients hospitalized with acute encephalitis during the study period, 48 (21.2%) were identified as having evidence of EBV-infection: convincing EBV serology and/or positive cerebrospinal fluid (CSF) polymerase chain reaction (PCR) in patients that had no bacterial cause of encephalitis. EBV monoinfection was registered in 24 (50%) patients. Mixed herpesvirus infection with one to four viruses in addition to EBV was detected in the rest. The most common symptoms were fever, confusion, headache, focal neurological deficits, vestibulo-ataxic disorders. CSF cytosis, content of protein and glucose were close to normal. Magnetic resonance imaging (MRI) showed focal (28/58.3%) and diffuse (15/31.3%) changes of the brain parenchymal. All patients got antiviral medication: ganciclovir, valganciclovir or valaciclovir, as a rule. Outcome: 26 (54%) patients recovered without any disabling sequela, 21 (44%) patients with remaining preservations were transferred to a convalescence facility. One patient, which condition worsened against the background of the therapy, were moved to an intensive care unit. No patient died.
CONCLUSION: Conclusions: CNS infection with EBV only and as a mixed infection is common in Ukraine. Presentation of EBV-infection is non-specific, both as MR imaging, sometimes reminding of HSV-1 infection. Prognosis of the disease is favorable.

PMID: 30267504 [PubMed - in process]

Human V2A: A map of the peripheral visual hemifield with functional connections to scene-selective cortex.

Sun, 09/30/2018 - 15:40
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Human V2A: A map of the peripheral visual hemifield with functional connections to scene-selective cortex.

J Vis. 2018 Sep 04;18(9):22

Authors: Elshout JA, van den Berg AV, Haak KV

Abstract
Humans can recognize a scene in the blink of an eye. This gist-based visual scene perception is thought to be underpinned by specialized visual processing emphasizing the visual periphery at a cortical locus relatively low in the visual processing hierarchy. Using wide-field retinotopic mapping and population receptive field (pRF) modeling, we identified a new visual hemifield map anterior of area V2d and inferior to area V6, which we propose to call area V2A. Based on its location relative to other visual areas, V2A may correspond to area 23V described in nonhuman primates. The pRF analysis revealed unique receptive field properties for V2A: a large (FWHM ∼23°) and constant receptive field size across the central ∼70° of the visual field. Resting-state fMRI connectivity analysis further suggests that V2A is ideally suited to quickly feed the scene-processing network with information that is not biased towards the center of the visual field. Our findings not only indicate a likely cortical locus for the initial stages of gist-based visual scene perception, but also suggest a reappraisal of the organization of human dorsomedial occipital cortex with a strip of separate hemifield representations anterior to the early visual areas (V1, V2d, and V3d).

PMID: 30267074 [PubMed - in process]

Oxytocin differentially modulates specific dorsal and ventral striatal functional connections with frontal and cerebellar regions.

Sun, 09/30/2018 - 15:40
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Oxytocin differentially modulates specific dorsal and ventral striatal functional connections with frontal and cerebellar regions.

Neuroimage. 2018 Sep 25;:

Authors: Zhao Z, Ma X, Geng Y, Zhao W, Zhou F, Wang J, Markett S, Biswal BB, Ma Y, Kendrick KM, Becker B

Abstract
Interactions between oxytocin and the basal ganglia are central in current overarching conceptualizations of its broad modulatory effects on behavior. Whereas evidence from animal models emphasizes the critical role of the ventral striatum in the behavioral effects of oxytocin, region-specific contributions of the basal ganglia have not been systematically explored in humans. The present study combined the randomized placebo-controlled administration of oxytocin versus placebo in healthy men (n = 144) with fMRI-based resting-state functional connectivity to determine the modulatory role of oxytocin on the major basal ganglia pathways. Oxytocin specifically increased connectivity between ventral striatal and pallidal nodes with up-stream frontal regions, whereas it decreased the strengths of downstream pathways between the dorsal striatum and posterior cerebellum. These pathways have previously been implicated in salience, reward and behavioral flexibility, thus shaping goal-directed behavior. Given the importance of aberrant striatal intrinsic organization in autism, addiction and schizophrenia the present findings may suggest new mechanistic perspectives for the therapeutic potential of oxytocin in these disorders.

PMID: 30266264 [PubMed - as supplied by publisher]

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