These are representative sample records from Science.gov related to your search topic.
For comprehensive and current results, perform a real-time search at Science.gov.
1

Task-Specific Functional Brain Geometry from Model Maps  

Microsoft Academic Search

In this paper we propose model maps to derive and repre- sent the intrinsic functional geometry of a brain from functional magnetic resonance imaging (fMRI) data for a specific task. Model maps repre- sent the coherence of behavior of individual fMRI-measurements for a set of observations, or a time sequence. The maps establish a relation between individual positions in the

Georg Langs; Dimitris Samaras; Nikos Paragios; Jean Honorio; Nelly Alia-klein; Dardo Tomasi; Nora D. Volkow; Rita Z. Goldstein

2008-01-01

2

Functional specificity for high-level linguistic processing in the human brain  

E-print Network

Neuroscientists have debated for centuries whether some regions of the human brain are selectively engaged in specific high-level mental functions or whether, instead, cognition is implemented in multifunctional brain ...

Fedorenko, Evelina G.

3

Electro-acupuncture at different acupoints modulating the relative specific brain functional network  

NASA Astrophysics Data System (ADS)

Objective: The specific brain effects of acupoint are important scientific concern in acupuncture. However, previous acupuncture fMRI studies focused on acupoints in muscle layer on the limb. Therefore, researches on acupoints within connective tissue at trunk are warranted. Material and Methods: Brain effects of acupuncture on abdomen at acupoints Guanyuan (CV4) and Zhongwan (CV12) were tested using fMRI on 21 healthy volunteers. The data acquisition was performed at resting state, during needle retention, electroacupuncture (EA) and post-EA resting state. Needling sensations were rated after every electroacupuncture (EA) procedure. The needling sensations and the brain functional activity and connectivity were compared between CV4 and CV12 using SPSS, SPM2 and the local and remote connectivity maps. Results and conclusion: EA at CV4 and CV12 induced apparent deactivation effects in the limbic-paralimbic-neocortical network. The default mode of the brain was modified by needle retention and EA, respectively. The functional brain network was significantly changed post EA. However, the minor differences existed between these two acupoints. The results demonstrated similarity between functional brain network mode of acupuncture modulation and functional circuits of emotional and cognitive regulation. Acupuncture may produce analgesia, anti-anxiety and anti-depression via the limbic-paralimbic-neocortical network (LPNN).

Fang, Jiliang; Wang, Xiaoling; Wang, Yin; Liu, Hesheng; Hong, Yang; Liu, Jun; Zhou, Kehua; Wang, Lei; Xue, Chao; Song, Ming; Liu, Baoyan; Zhu, Bing

2010-11-01

4

Functional specificity in the human brain: A window into the functional architecture of the mind  

E-print Network

Is the human mind/brain composed of a set of highly specialized components, each carrying out a specific aspect of human cognition, or is it more of a general-purpose device, in which each component participates in a wide ...

Kanwisher, Nancy

5

Topographically specific functional connectivity between visual field maps in the human brain  

Microsoft Academic Search

Neural activity in mammalian brains exhibits large spontaneous fluctuations whose structure reveals the intrinsic functional connectivity of the brain on many spatial and temporal scales. Between remote brain regions, spontaneous activity is organized into large-scale functional networks. To date, it has remained unclear whether the intrinsic functional connectivity between brain regions scales down to the fine detail of anatomical connections,

Jakob Heinzle; Thorsten Kahnt; John-Dylan Haynes

2011-01-01

6

Functional specificity for high-level linguistic processing in the human brain  

PubMed Central

Neuroscientists have debated for centuries whether some regions of the human brain are selectively engaged in specific high-level mental functions or whether, instead, cognition is implemented in multifunctional brain regions. For the critical case of language, conflicting answers arise from the neuropsychological literature, which features striking dissociations between deficits in linguistic and nonlinguistic abilities, vs. the neuroimaging literature, which has argued for overlap between activations for linguistic and nonlinguistic processes, including arithmetic, domain general abilities like cognitive control, and music. Here, we use functional MRI to define classic language regions functionally in each subject individually and then examine the response of these regions to the nonlinguistic functions most commonly argued to engage these regions: arithmetic, working memory, cognitive control, and music. We find little or no response in language regions to these nonlinguistic functions. These data support a clear distinction between language and other cognitive processes, resolving the prior conflict between the neuropsychological and neuroimaging literatures. PMID:21885736

Fedorenko, Evelina; Behr, Michael K.; Kanwisher, Nancy

2011-01-01

7

Molecular and functional characterization of riboflavin specific transport system in rat brain capillary endothelial cells  

PubMed Central

Riboflavin is an important water soluble vitamin (B2) required for metabolic reactions, normal cellular growth, differentiation and function. Mammalian brain cells cannot synthesize riboflavin and must import from systemic circulation. However, the uptake mechanism, cellular translocation and intracellular trafficking of riboflavin in brain capillary endothelial cells are poorly understood. The primary objective of this study is to investigate the existence of riboflavin-specific transport system and delineate the uptake and intracellular regulation of riboflavin in immortalized rat brain capillary endothelial cells (RBE4). The uptake of [3H]-Riboflavin is sodium, temperature and energy dependent but pH independent. [3H]-Riboflavin uptake is saturable with Km and Vmax values of 19 ± 3 µM and 0.235 ± 0.012 picomoles/min/mg protein, respectively. The uptake process is inhibited by unlabelled structural analogs (lumiflavin, lumichrome) but not by structurally unrelated vitamins. Ca++/calmodulin and protein kinase A (PKA) pathways are found to play an important role in the intracellular regulation of [3H]-Riboflavin. Apical and baso-lateral uptake of [3H]-Riboflavin clearly indicate that riboflavin specific transport system is predominantly localized on the apical side of RBE4 cells. A 628 bp band corresponding to riboflavin transporter is revealed in RT-PCR analysis. These findings, for the first time report the existence of a specialized and high affinity transport system for riboflavin in RBE4 cells. Blood-brain barrier (BBB) is a major obstacle limiting drug transport inside the brain as it regulates drug permeation from systemic circulation. This transporter can be utilized for targeted delivery in enhancing brain permeation of highly potent drugs on systemic administration. PMID:22683359

Patel, Mitesh; Vadlapatla, Ramya Krishna; Pal, Dhananjay; Mitra, Ashim K.

2012-01-01

8

Non-verbal emotion communication training induces specific changes in brain function and structure  

PubMed Central

The perception of emotional cues from voice and face is essential for social interaction. However, this process is altered in various psychiatric conditions along with impaired social functioning. Emotion communication trainings have been demonstrated to improve social interaction in healthy individuals and to reduce emotional communication deficits in psychiatric patients. Here, we investigated the impact of a non-verbal emotion communication training (NECT) on cerebral activation and brain structure in a controlled and combined functional magnetic resonance imaging (fMRI) and voxel-based morphometry study. NECT-specific reductions in brain activity occurred in a distributed set of brain regions including face and voice processing regions as well as emotion processing- and motor-related regions presumably reflecting training-induced familiarization with the evaluation of face/voice stimuli. Training-induced changes in non-verbal emotion sensitivity at the behavioral level and the respective cerebral activation patterns were correlated in the face-selective cortical areas in the posterior superior temporal sulcus and fusiform gyrus for valence ratings and in the temporal pole, lateral prefrontal cortex and midbrain/thalamus for the response times. A NECT-induced increase in gray matter (GM) volume was observed in the fusiform face area. Thus, NECT induces both functional and structural plasticity in the face processing system as well as functional plasticity in the emotion perception and evaluation system. We propose that functional alterations are presumably related to changes in sensory tuning in the decoding of emotional expressions. Taken together, these findings highlight that the present experimental design may serve as a valuable tool to investigate the altered behavioral and neuronal processing of emotional cues in psychiatric disorders as well as the impact of therapeutic interventions on brain function and structure. PMID:24146641

Kreifelts, Benjamin; Jacob, Heike; Bruck, Carolin; Erb, Michael; Ethofer, Thomas; Wildgruber, Dirk

2013-01-01

9

Frequency-specific functional connectivity in the brain during resting state revealed by NIRS.  

PubMed

Analyses of spontaneous hemodynamic fluctuations observed on functional magnetic resonance imaging (fMRI) have revealed the existence of temporal correlations in signal changes between widely separated brain regions during the resting state, termed "resting state functional connectivity." Recent studies have demonstrated that these correlations are also present in the hemodynamic signals measured by near infrared spectroscopy (NIRS). However, it is still uncertain whether frequency-specific characteristics exist in these signals. In the present study, we used multichannel NIRS to investigate the frequency dependency of functional connectivity between diverse regions in the cerebral cortex by decomposing fluctuations of oxygenated hemoglobin (oxy-Hb) and deoxygenated hemoglobin (deoxy-Hb) signals into various frequency bands. First, within a wide frequency range (0.009-0.1Hz), we observed that both oxy-Hb and deoxy-Hb signals showed functional connectivity within local regions and between contralateral hemispheric regions of the cortex. Next, by decomposing measured fluctuations into narrower frequency components, we determined that only oxy-Hb signals showed frequency-specific functional connectivity between the frontal and occipital regions, emerging in a narrow frequency range (0.04-0.1Hz). To clarify the coherency of functional connectivity, we calculated the average coherence values between selected channel pairs. This approach demonstrated that functional connectivity based on the oxy-Hb signals between homologous cortical regions of the contralateral hemisphere (homologous connectivity) showed high coherence over a wide frequency range (0.009-0.1Hz), whereas connectivity between the prefrontal and occipital regions (fronto-posterior connectivity) showed high coherence only within a specific narrow frequency range (0.04-0.1Hz). Our findings suggest that homologous connectivity may reflect synchronization of neural activation over a wide frequency range through direct neuroanatomical connections, whereas fronto-posterior connectivity as revealed by high coherence only within a specific narrow frequency range corresponding to the time scale of typical hemodynamic response to a single event may reflect synchronization of transient neural activation among distant cortical regions. The present study demonstrated that NIRS provides a powerful tool to elucidate network properties of the cortex during resting state. PMID:21211570

Sasai, Shuntaro; Homae, Fumitaka; Watanabe, Hama; Taga, Gentaro

2011-05-01

10

Brain Structure and Brain Function  

ERIC Educational Resources Information Center

This paper has attempted to provide information in brief form regarding the structure of the brain, the types of pathological conditions that involve the brain, some of the conventional neurological diagnostic methods, and illustrations of the importance of intact brain functions for performances in the area of language functions and visuo-spatial…

Reitan, Ralph M.

1970-01-01

11

Cyclooxygenase-2-specific Inhibitor Improves Functional Outcomes, Provides Neuroprotection, and Reduces Inflammation in a Rat Model of Traumatic Brain Injury  

PubMed Central

OBJECTIVE Increases in brain cyclooxygenase-2 (COX2) are associated with the central inflammatory response and with delayed neuronal death, events that cause secondary insults after traumatic brain injury. A growing literature supports the benefit of COX2-specific inhibitors in treating brain injuries. METHODS DFU [5,5-dimethyl-3(3-fluorophenyl)-4(4-methylsulfonyl)phenyl-2(5H)-furanone] is a third-generation, highly specific COX2 enzyme inhibitor. DFU treatments (1 or 10 mg/kg intraperitoneally, twice daily for 3 d) were initiated either before or after traumatic brain injury in a lateral cortical contusion rat model. RESULTS DFU treatments initiated 10 minutes before injury or up to 6 hours after injury enhanced functional recovery at 3 days compared with vehicle-treated controls. Significant improvements in neurological reflexes and memory were observed. DFU initiated 10 minutes before injury improved histopathology and altered eicosanoid profiles in the brain. DFU 1 mg/kg reduced the rise in prostaglandin E2 in the brain at 24 hours after injury. DFU 10 mg/kg attenuated injury-induced COX2 immunoreactivity in the cortex (24 and 72 h) and hippocampus (6 and 72 h). This treatment also decreased the total number of activated caspase-3–immunoreactive cells in the injured cortex and hippocampus, significantly reducing the number of activated caspase-3–immunoreactive neurons at 72 hours after injury. DFU 1 mg/kg amplified potentially anti-inflammatory epoxyeicosatrienoic acid levels by more than fourfold in the injured brain. DFU 10 mg/kg protected the levels of 2-arachidonoyl glycerol, a neuro-protective endocannabinoid, in the injured brain. CONCLUSION These improvements, particularly when treatment began up to 6 hours after injury, suggest exciting neuroprotective potential for COX2 inhibitors in the treatment of traumatic brain injury and support the consideration of Phase I/II clinical trials. PMID:15730585

Gopez, Jonas J.; Yue, Hongfei; Vasudevan, Ram; Malik, Amir S.; Fogelsanger, Lester N.; Lewis, Shawn; Panikashvili, David; Shohami, Esther; Jansen, Susan A.; Narayan, Raj K.; Strauss, Kenneth I.

2006-01-01

12

Human Functional Brain Imaging  

E-print Network

Human Functional Brain Imaging 1990­2009 September 2011 Portfolio Review Summary Brain Imaging #12 Dale ­ one of our first Trustees. Understanding the brain remains one of our key strategic aims today three-fold: · to identify the key landmarks and influences on the human functional brain imaging

Rambaut, Andrew

13

Human Functional Brain Imaging  

E-print Network

Human Functional Brain Imaging 1990­2009 September 2011 Portfolio Review #12;2 | Portfolio Review: Human Functional Brain ImagingThe Wellcome Trust is a charity registered in England and Wales, no's role in supporting human functional brain imaging and have informed `our' speculations for the future

Rambaut, Andrew

14

Evidence from brain imaging with fMRI supporting functional specificity of acupoints in humans  

Microsoft Academic Search

We tested whether the stimulation of acupoints in the same spinal segments could induce different central responses with functional magnetic resonance imaging (fMRI) study. Stimulation of acupoints ST36\\/SP6 (Zusanli\\/Sanyinjiao) or GB34\\/BL57 (Yanglingquan\\/Chengshan) both activated primary and secondary somatosensory area, insula, ventral thalamus, parietal Brodmann Area 40, temporal lobe, putamen, and cerebellum, while de-activated amygdala. Nevertheless, ST36\\/SP6 stimulation specifically activated orbital

Wei-Ting Zhang; Zhen Jin; Fei Luo; Lei Zhang; Ya-Wei Zeng; Ji-Sheng Han

2004-01-01

15

Specifically Progressive Deficits of Brain Functional Marker in Amnestic Type Mild Cognitive Impairment  

Microsoft Academic Search

BackgroundDeficits of the default mode network (DMN) have been demonstrated in subjects with amnestic type mild cognitive impairment (aMCI) who have a high risk of developing Alzheimer’s disease (AD). However, no longitudinal study of this network has been reported in aMCI. Identifying links between development of DMN and aMCI progression would be of considerable value in understanding brain changes underpinning

Feng Bai; David R. Watson; Yongmei Shi; Yi Wang; Chunxian Yue; Yuhuanteng; Di Wu; Yonggui Yuan; Zhijun Zhang; Jerson Laks

2011-01-01

16

The question of domain specificity in brain function has been a long-  

E-print Network

of specific right frontal re- gions during successful memorization of nonverbal materials, with encoding of Radiology, Washington University School of Medicine, St Louis, MO 63110, USA. R.L. Buckner is at the Departments of Radiology, and Anatomy & Neurobiology, Washington University School of Medicine, St Louis, MO

Kelley, William M.

17

[Dehydroepiandrosterone and brain functioning].  

PubMed

The adrenal glands synthesize dehydroepiandrosterone (DHEA) and its sulphate form (DHEAS) more intensively than they do other steroid hormones. Researchers are interested in these hormones for several reasons. Firstly, for some years they have been trying to find the reason for DHEA and DHEAS to be synthesized and present in the organism in such high concentrations. Secondly, their attention have been attracted by age-dependent regression of DHEA, which is strictly determined. Thirdly, despite longstanding efforts of scientists, the physiological role and spectrum of the biological activity of DHEA is still unclear. Evidence of that DHEA and DHEAS can be synthesized in situ in the brain tissue, received in rat experiments, urged researchers to clarify the role of these neurosteroids in the CNS. The presented review covers ways of neurosteroid synthesis, possible mechanisms of the regulation of these processes, and their dynamics under the condition of stress. The authors analyze experimental and clinical observations undertaken with a goal to clarify a possible role of DHEA in the manifestation of various brain functions. Special attention is payed to ambiguous results of modern studies, dedicated to replacement therapy of various disorders of CNS functioning (Alzheimer's disease, depression, age-specific memory impairment, sleep disturbance etc.) with DHEAS. PMID:16149434

Goncharov, N P; Katsiia, G V; Nizhnik, A N

2005-01-01

18

Split Brain Functioning.  

ERIC Educational Resources Information Center

Summarizing recent research, this article defines the functions performed by the left and right sides of the human brain. Attention is given to the right side, or the nondominant side, of the brain and its potential in terms of perception of the environment, music, art, geometry, and the aesthetics. (JC)

Cassel, Russell N.

1978-01-01

19

Brain Hemispheric Functioning.  

ERIC Educational Resources Information Center

Four articles consider brain hemisphere functioning of gifted students as it relates to gifted programs; alternation of education methodologies; spatial ability as an element of intellectual gifted functioning; and the interaction between hemisphere specialization, imagery, creative imagination, and sex differentiation. (SB)

Roeper Review, 1981

1981-01-01

20

Association of Parent Ratings of Executive Function With Global- and Setting-Specific Behavioral Impairment After Adolescent Traumatic Brain Injury  

PubMed Central

Objective To determine the association of primary caregiver-rated behavioral and metacognitive aspects of executive function (EF) with impaired functioning after adolescent traumatic brain injury (TBI). Design Multicenter cross-sectional study. Setting Outpatient. Participants Primary caregivers and children (N = 132) aged 12 to 17 years who sustained a moderate or severe TBI within the past 1 to 6 months. Interventions Not applicable. Main Outcome Measures Primary caregiver ratings of EF, tests of memory and processing speed (PS), and a structured parent interview to assess clinical impairments in behavioral functioning were used. Logistic regression was used to examine the relation of ratings of EF with clinical ratings of impairment in global adolescent functioning and in functioning in the home, school, and community settings after controlling for sex, race, socioeconomic status, injury severity, and performance on the tests of memory and PS. Results Caregiver ratings of poor EF were associated with impairment in both global behavioral functioning (odds ratio [OR] = 4.73; 95% confidence interval [CI], 1.54–14.52; P<.01) and community functioning (OR = 13.28; 95% CI, 1.94–90.87; P<.01). Conclusions Caregiver ratings of deficits in EF were associated with impaired behavioral functioning after adolescent TBI and were independent of performance on tests of memory and processing speed. Understanding the relation of EF with clinical impairments as manifested in different settings will help hone assessment batteries and focus treatments where they are needed most. PMID:23131527

Kurowski, Brad G.; Wade, Shari L.; Kirkwood, Michael W.; Brown, Tanya M.; Stancin, Terry; Cassedy, Amy; Taylor, H. Gerry

2013-01-01

21

Functional Aspects of Creatine Kinase in Brain  

Microsoft Academic Search

The distinct isoenzyme-specific localization of creatine kinase (CK) isoenzymes found recently in brain suggests an important function for CK in brain energetics and points to adaptation of the CK system to the special energy requirements of different neuronal and glial cell types. For example, the presence of brain-type B-CK in Bergmann glial cells and astrocytes is very likely related to

Wolfram Hemmer; Theo Wallimann

1993-01-01

22

Methods for functional brain imaging  

E-print Network

Magnetic resonance imaging (MRI) has demonstrated the potential for non-invasive mapping of structure and function (fMRI) in the human brain. In this thesis, we propose a series of methodological developments towards ...

Witzel, Thomas, Ph. D. Massachusetts Institute of Technology

2011-01-01

23

Functional brain mapping of psychopathology  

PubMed Central

In this paper, we consider the impact that the novel functional neuroimaging techniques may have upon psychiatric illness. Functional neuroimaging has rapidly developed as a powerful tool in cognitive neuroscience and, in recent years, has seen widespread application in psychiatry. Although such studies have produced evidence for abnormal patterns of brain response in association with some pathological conditions, the core pathophysiologies remain unresolved. Although imaging techniques provide an unprecedented opportunity for investigation of physiological function of the living human brain, there are fundamental questions and assumptions which remain to be addressed. In this review we examine these conceptual issues under three broad sections: (1) characterising the clinical population of interest, (2) defining appropriate levels of description of normal brain function, and (3) relating these models to pathophysiological conditions. Parallel advances in each of these questions will be required before imaging techniques can impact on clinical decisions in psychiatry. PMID:11909899

Honey, G; Fletcher, P; Bullmore, E

2002-01-01

24

[Sleep and brain function].  

PubMed

Lipocalin-type prostaglandin (PG) D synthase (L-PGDS) catalyzes the isomerization of PGH2, a common precursor of various prostanoids, to produce PGD2, a potent endogenous somnogen. L-PGDS is localized in the leptomeninges, choroid plexus, and oligodendrocytes of the central nervous system. PGD2 is proposed to be a major humoral sleep-inducing factor accumulated in the brain during wakefulness. PGD2 stimulates DP, receptors localized in the basal forebrain and increases the local extracellular concentration of adenosine, which activates A2A receptor-possessing neurons in the basal forebrain and/or ventrolateral preoptic area (VLPO). The intracerebroventricular infusion of PGD2 or adenosine A2A receptor-agonists induces non-REM sleep and increases the expression of fos protein in VLPO. The activation of VLPO neurons is associated with decreased fos expression in the histaminergic tuberomammillary nucleus (TMN), one of the arousal centers. The GABAergic inhibition of TMN is involved in non-REM sleep induction by PGD2 or adenosine A2A receptor-agonists. The neural network between VLPO and TMN is considered to play a key role in the regulation of vigilance states. PMID:16986732

Urade, Yoshihiro; Mohri, Ikuko

2006-09-01

25

Organization, development and function of complex brain networks  

Microsoft Academic Search

Recent research has revealed general principles in the structural and functional organization of complex networks which are shared by various natural, social and technological systems. This review examines these principles as applied to the organization, development and function of complex brain networks. Specifically, we examine the structural properties of large-scale anatomical and functional brain networks and discuss how they might

Olaf Sporns; Dante R. Chialvo; Marcus Kaiser; Claus C. Hilgetag

2004-01-01

26

Specific Binding of Atrial Natriuretic Factor in Brain Microvessels  

NASA Astrophysics Data System (ADS)

Cerebral capillaries constitute the blood--brain barrier. Studies of specific receptors (neurotransmitters or hormones) located on this structure can be performed by means of radioligand-binding techniques on isolated brain microvessels. We examined on pure bovine cerebral microvessel preparations the binding of atrial natriuretic factor (ANF), using 125I-labeled ANF. Saturation and competition experiments demonstrated the presence of a single class of ANF-binding sites with high affinity (dissociation constant, ? 10-10 M) and with a binding capacity of 58 fmol/mg of protein. The binding of 125I-labeled ANF to brain microvessels is specific, reversible, and time dependent, as is shown by association-dissociation experiments. The demonstration of specific ANF-binding sites on brain microvessels supposes a physiological role of ANF on brain microvasculature. The coexistence of ANF and angiotensin II receptors on this cerebrovascular tissue suggests that the two circulating peptides may act as mutual antagonists in the regulation of brain microcirculation and/or blood--brain barrier function.

Chabrier, Pierre E.; Roubert, Pierre; Braquet, Pierre

1987-04-01

27

Secretin: specific binding to rat brain membranes  

SciTech Connect

The binding of (/sup 125/I)secretin to rat brain membranes was investigated. Radiolabeled secretin bound with high affinity (KD . 0.2 nM) to a single class of noninteracting sites. Binding was specific, saturable, and reversible. Regional distribution studies indicated that the specific binding was greatest in the cerebellum, intermediate in the cortex, thalamus, striatum, hippocampus, and hypothalamus, and lowest in the midbrain and medulla/pons. Pharmacological studies indicated that only secretin, but not other peptides, inhibits binding of (/sup 125/I)secretin with high affinity. Also, certain guanine nucleotides inhibited high affinity binding. These data indicate that rat brain membranes possess high affinity binding sites specific for secretin and that with the use of (/sup 125/I) secretin the kinetics, stoichiometry, specificity, and distribution of secretin receptors can be directly investigated.

Fremeau, R.T. Jr.; Jensen, R.T.; Charlton, C.G.; Miller, R.L.; O'Donohue, T.L.; Moody, T.W.

1983-08-01

28

Brain-derived neurotrophic factor ( BDNF) gene: a gender-specific role in cognitive function during normal cognitive aging of the MEMO-Study?  

Microsoft Academic Search

Cognitive aging processes are underpinned by multiple processes including genetic factors. The brain-derived neurotrophic\\u000a factor (BDNF) has been suggested to be involved in age-related cognitive decline in otherwise healthy individuals. The gender-specific\\u000a role of the BDNF gene in cognitive aging remains unclear. The identification of genetic biomarkers might be a useful approach to identify\\u000a individuals at risk of cognitive decline

Katharine R. Laing; David Mitchell; Heike Wersching; Maria E. Czira; Klaus Berger; Bernhard T. Baune

29

Functional brain imaging across development.  

PubMed

The developmental cognitive neuroscience literature has grown exponentially over the last decade. This paper reviews the functional magnetic resonance imaging (fMRI) literature on brain function development of typically late developing functions of cognitive and motivation control, timing and attention as well as of resting state neural networks. Evidence shows that between childhood and adulthood, concomitant with cognitive maturation, there is progressively increased functional activation in task-relevant lateral and medial frontal, striatal and parieto-temporal brain regions that mediate these higher level control functions. This is accompanied by progressively stronger functional inter-regional connectivity within task-relevant fronto-striatal and fronto-parieto-temporal networks. Negative age associations are observed in earlier developing posterior and limbic regions, suggesting a shift with age from the recruitment of "bottom-up" processing regions towards "top-down" fronto-cortical and fronto-subcortical connections, leading to a more mature, supervised cognition. The resting state fMRI literature further complements this evidence by showing progressively stronger deactivation with age in anti-correlated task-negative resting state networks, which is associated with better task performance. Furthermore, connectivity analyses during the resting state show that with development increasingly stronger long-range connections are being formed, for example, between fronto-parietal and fronto-cerebellar connections, in both task-positive networks and in task-negative default mode networks, together with progressively lesser short-range connections, suggesting progressive functional integration and segregation with age. Overall, evidence suggests that throughout development between childhood and adulthood, there is progressive refinement and integration of both task-positive fronto-cortical and fronto-subcortical activation and task-negative deactivation, leading to a more mature and controlled cognition. PMID:22729957

Rubia, Katya

2013-12-01

30

Non-invasive brain-to-brain interface (BBI): establishing functional links between two brains.  

PubMed

Transcranial focused ultrasound (FUS) is capable of modulating the neural activity of specific brain regions, with a potential role as a non-invasive computer-to-brain interface (CBI). In conjunction with the use of brain-to-computer interface (BCI) techniques that translate brain function to generate computer commands, we investigated the feasibility of using the FUS-based CBI to non-invasively establish a functional link between the brains of different species (i.e. human and Sprague-Dawley rat), thus creating a brain-to-brain interface (BBI). The implementation was aimed to non-invasively translate the human volunteer's intention to stimulate a rat's brain motor area that is responsible for the tail movement. The volunteer initiated the intention by looking at a strobe light flicker on a computer display, and the degree of synchronization in the electroencephalographic steady-state-visual-evoked-potentials (SSVEP) with respect to the strobe frequency was analyzed using a computer. Increased signal amplitude in the SSVEP, indicating the volunteer's intention, triggered the delivery of a burst-mode FUS (350 kHz ultrasound frequency, tone burst duration of 0.5 ms, pulse repetition frequency of 1 kHz, given for 300 msec duration) to excite the motor area of an anesthetized rat transcranially. The successful excitation subsequently elicited the tail movement, which was detected by a motion sensor. The interface was achieved at 94.0±3.0% accuracy, with a time delay of 1.59±1.07 sec from the thought-initiation to the creation of the tail movement. Our results demonstrate the feasibility of a computer-mediated BBI that links central neural functions between two biological entities, which may confer unexplored opportunities in the study of neuroscience with potential implications for therapeutic applications. PMID:23573251

Yoo, Seung-Schik; Kim, Hyungmin; Filandrianos, Emmanuel; Taghados, Seyed Javid; Park, Shinsuk

2013-01-01

31

The Big Five default brain: functional evidence.  

PubMed

Recent neuroimaging studies have provided evidence that different dimensions of human personality may be associated with specific structural neuroanatomic correlates. Identifying brain correlates of a situation-independent personality structure would require evidence of a stable default mode of brain functioning. In this study, we investigated the correlates of the Big Five personality dimensions (Extraversion, Neuroticism, Openness/Intellect, Agreeableness, and Conscientiousness) and the default mode network (DMN). Forty-nine healthy adults completed the NEO-Five Factor. The results showed that the Extraversion (E) and Agreeableness (A) were positively correlated with activity in the midline core of the DMN, whereas Neuroticism (N), Openness (O), and Conscientiousness (C) were correlated with the parietal cortex system. Activity of the anterior cingulate cortex was positively associated with A and negatively with C. Regions of the parietal lobe were differentially associated with each personality dimension. The present study not only confirms previous functional correlates regarding the Big Five personality dimensions, but it also expands our knowledge showing the association between different personality dimensions and specific patterns of brain activation at rest. PMID:23881294

Sampaio, Adriana; Soares, José Miguel; Coutinho, Joana; Sousa, Nuno; Gonçalves, Oscar F

2014-11-01

32

Aging and functional brain networks  

SciTech Connect

Aging is associated with changes in human brain anatomy and function and cognitive decline. Recent studies suggest the aging decline of major functional connectivity hubs in the 'default-mode' network (DMN). Aging effects on other networks, however, are largely unknown. We hypothesized that aging would be associated with a decline of short- and long-range functional connectivity density (FCD) hubs in the DMN. To test this hypothesis, we evaluated resting-state data sets corresponding to 913 healthy subjects from a public magnetic resonance imaging database using functional connectivity density mapping (FCDM), a voxelwise and data-driven approach, together with parallel computing. Aging was associated with pronounced long-range FCD decreases in DMN and dorsal attention network (DAN) and with increases in somatosensory and subcortical networks. Aging effects in these networks were stronger for long-range than for short-range FCD and were also detected at the level of the main functional hubs. Females had higher short- and long-range FCD in DMN and lower FCD in the somatosensory network than males, but the gender by age interaction effects were not significant for any of the networks or hubs. These findings suggest that long-range connections may be more vulnerable to aging effects than short-range connections and that, in addition to the DMN, the DAN is also sensitive to aging effects, which could underlie the deterioration of attention processes that occurs with aging.

Tomasi D.; Tomasi, D.; Volkow, N.D.

2011-07-11

33

Sugar for the brain: the role of glucose in physiological and pathological brain function  

PubMed Central

The mammalian brain depends upon glucose as its main source of energy, and tight regulation of glucose metabolism is critical for brain physiology. Consistent with its critical role for physiological brain function, disruption of normal glucose metabolism as well as its interdependence with cell death pathways forms the pathophysiological basis for many brain disorders. Here, we review recent advances in understanding how glucose metabolism sustains basic brain physiology. We aim at synthesizing these findings to form a comprehensive picture of the cooperation required between different systems and cell types, and the specific breakdowns in this cooperation which lead to disease. PMID:23968694

Mergenthaler, Philipp; Lindauer, Ute; Dienel, Gerald A.; Meisel, Andreas

2013-01-01

34

Dolichol alters brain membrane functions  

SciTech Connect

It has been well demonstrated that there is a direct correlation between increase in dolichol level in brain and aging. An abnormally high level of dolichol was found in brain tissue of patients with pathological aging disorders. The aim of this study is to examine the physiological significance of dolichol affecting membrane transport activity and phospholipid acyl group turnover. Dolichol added to synaptic plasma membranes resulted in a biphasic effect on (Na/sup +/, K/sup +/)-ATPase, i.e., an enhancement of activity at low concentrations (5 ..mu..g/125 mg protein) and an inhibition of activity at high concentrations (40-100 ..mu..g). To probe the membrane acyl group turnover, the incorporation of (/sup 14/C)-arachidonate into plasma membrane phospholipids was examined in the presence and absence of dolichol. Dolichol elicited an increase in the incorporation of label into phospholipids. However, the effects varied depending on whether BSA is present. In the absence of BSA, the increase in labeling of phosphatidylinositols is higher than that of phosphatidylcholines. These results suggest that dolichols, when inserted into membranes, may alter membrane functions.

Sun, G.Y.; Sun, A.Y.; Schroeder, F.; Wood, G.; Strong, R.

1986-03-05

35

Brain Surface Conformal Parameterization with Algebraic Functions  

E-print Network

Brain Surface Conformal Parameterization with Algebraic Functions Yalin Wang1,2 , Xianfeng Gu3 a brain surface to a multi-hole disk. The re- sulting parameterizations do not have any singularities of anatomical surfaces in MRI scans of the brain, in- cluding the hippocampi and the cerebral cortices

Wang, Yalin

36

Brain dynamics promotes function Carlos Lourenco  

E-print Network

Brain dynamics promotes function Carlos Louren¸co 1 Faculty of Sciences of the University of Lisbon, 1049-001 Lisboa - Portugal Abstract. Dynamical structure in the brain promotes biological func- tion. Computational scientists have new opportunities to receive 'algorithmic' inspiration from brain processes

Lisboa, Universidade Técnica de

37

Promoting Motor Function by Exercising the Brain  

PubMed Central

Exercise represents a behavioral intervention that enhances brain health and motor function. The increase in cerebral blood volume in response to physical activity may be responsible for improving brain function. Among the various neuroimaging techniques used to monitor brain hemodynamic response during exercise, functional near-infrared spectroscopy could facilitate the measurement of task-related cortical responses noninvasively and is relatively robust with regard to the subjects’ motion. Although the components of optimal exercise interventions have not been determined, evidence from animal and human studies suggests that aerobic exercise with sufficiently high intensity has neuroprotective properties and promotes motor function. This review provides an insight into the effect of physical activity (based on endurance and resistance exercises) on brain function for producing movement. Since most progress in the study of brain function has come from patients with neurological disorders (e.g., stroke and Parkinson’s patients), this review presents some findings emphasizing training paradigms for restoring motor function. PMID:24961309

Perrey, Stephane

2013-01-01

38

Functional Data Analysis in Brain Imaging Studies  

PubMed Central

Functional data analysis (FDA) considers the continuity of the curves or functions, and is a topic of increasing interest in the statistics community. FDA is commonly applied to time-series and spatial-series studies. The development of functional brain imaging techniques in recent years made it possible to study the relationship between brain and mind over time. Consequently, an enormous amount of functional data is collected and needs to be analyzed. Functional techniques designed for these data are in strong demand. This paper discusses three statistically challenging problems utilizing FDA techniques in functional brain imaging analysis. These problems are dimension reduction (or feature extraction), spatial classification in functional magnetic resonance imaging studies, and the inverse problem in magneto-encephalography studies. The application of FDA to these issues is relatively new but has been shown to be considerably effective. Future efforts can further explore the potential of FDA in functional brain imaging studies. PMID:21833205

Tian, Tian Siva

2010-01-01

39

[Functional brain plasticity associated with motor learning].  

PubMed

This review presents the results of studies carried out in our laboratory that aim to investigate, through functional magnetic resonance imaging (fMRI), the brain plasticity associated with motor sequence learning, defined as our ability to integrate simple stereotyped movements into a single motor representation. Following a brief description of Doyon and colleagues' model (2002, 2005, 2009) of motor skill learning that has guided this work, we then describe the functional changes that occur at the different (rapid, slow, automatization) acquisition phases, and propose specific roles that the putamen, the cerebellum and their motor-related cortical areas, play in this form of motor behavior. Finally, we put forward evidence that post-training, non-REM sleep (and spindles in Stage 2 sleep, in particular) contributes to the consolidation of a motor sequence memory trace, and that increased activity within the striatum and/or the hippocampus mediates this mnemonic process. PMID:21524407

Doyon, Julien; Orban, Pierre; Barakat, Marc; Debas, Karen; Lungu, Ovidiu; Albouy, Geneviève; Fogel, Stuart; Proulx, Sébastien; Laventure, Samuel; Deslauriers, Jonathan; Duchesne, Catherine; Carrier, Julie; Benali, Habib

2011-04-01

40

Functional specifications for mathematical computations  

SciTech Connect

Are functional programs useful for specifying numerical computations We believe they certainly are, despite the long-established tradition of using procedural languages for such computations. We have prepared a pure functional specification for an algorithm that solves one-dimensional hyperbolic partial differential equations (PDEs). Using automated program transformations, we have derived a Fortran program from this specification that executes faster on a CRAY X-MP than does the hand-written Fortran implementation of the same algorithm. We discuss the development of the initial specification for the one-dimensional problem and its evolution into a second specification for solving multidimensional hyperbolic PDEs. In this second specification, the dimensionality of the problem is completely parameterized and is given by specifying the set of neighbors of a cell in the grid. Thus, programs can be derived from this specification to solve hyperbolic PDEs of any given dimensionality. Our goal is to elucidate how we approach specifying numerical computations in the functional style and to show how we take advantage of the modularity and abstractness of functional programming to obtain a very high-level representation of the algorithm. We also briefly discuss transformational derivation of efficient programs from such specifications. 13 refs., 1 tab.

Boyle, J.M. (Argonne National Lab., IL (USA)); Harmer, T.J. (Queen's Univ., Belfast, Northern Ireland (UK). Dept. of Computer Science)

1991-01-01

41

Energetic cost of brain functional connectivity  

PubMed Central

The brain's functional connectivity is complex, has high energetic cost, and requires efficient use of glucose, the brain's main energy source. It has been proposed that regions with a high degree of functional connectivity are energy efficient and can minimize consumption of glucose. However, the relationship between functional connectivity and energy consumption in the brain is poorly understood. To address this neglect, here we propose a simple model for the energy demands of brain functional connectivity, which we tested with positron emission tomography and MRI in 54 healthy volunteers at rest. Higher glucose metabolism was associated with proportionally larger MRI signal amplitudes, and a higher degree of connectivity was associated with nonlinear increases in metabolism, supporting our hypothesis for the energy efficiency of the connectivity hubs. Basal metabolism (in the absence of connectivity) accounted for 30% of brain glucose utilization, which suggests that the spontaneous brain activity accounts for 70% of the energy consumed by the brain. The energy efficiency of the connectivity hubs was higher for ventral precuneus, cerebellum, and subcortical hubs than for cortical hubs. The higher energy demands of brain communication that hinges upon higher connectivity could render brain hubs more vulnerable to deficits in energy delivery or utilization and help explain their sensitivity to neurodegenerative conditions, such as Alzheimer’s disease. PMID:23898179

Tomasi, Dardo; Wang, Gene-Jack; Volkow, Nora D.

2013-01-01

42

Brain Function: Implications for Schooling.  

ERIC Educational Resources Information Center

The implications of cerebral dominance for curriculum and instruction are enormous. Cognitive style, sex differences, instructional materials preparation and selection, and testing are affected by right or left brain hemisphere dominance. (CJ)

Edwards, Clifford H.

1982-01-01

43

Toward discovery science of human brain function  

Microsoft Academic Search

Although it is being successfully implemented for exploration of the genome, discovery science has eluded the functional neuroimaging community. The core challenge remains the development of common paradigms for interrogating the myriad functional systems in the brain without the constraints of a priori hypotheses. Resting-state functional MRI (R-fMRI) constitutes a candidate approach capable of addressing this challenge. Imaging the brain

B. B. Biswal; M. Mennes; X.-N. Zuo; S. Gohel; C. Kelly; S. M. Smith; C. F. Beckmann; J. S. Adelstein; R. L. Buckner; S. Colcombe; A.-M. Dogonowski; M. Ernst; D. Fair; M. Hampson; M. J. Hoptman; J. S. Hyde; V. J. Kiviniemi; R. Kotter; S.-J. Li; C.-P. Lin; M. J. Lowe; C. Mackay; D. J. Madden; K. H. Madsen; D. S. Margulies; H. S. Mayberg; K. McMahon; C. S. Monk; S. H. Mostofsky; B. J. Nagel; J. J. Pekar; S. J. Peltier; S. E. Petersen; V. Riedl; S. A. R. B. Rombouts; B. Rypma; B. L. Schlaggar; S. Schmidt; R. D. Seidler; G. J. Siegle; C. Sorg; G.-J. Teng; J. Veijola; A. Villringer; M. Walter; L. Wang; X.-C. Weng; S. Whitfield-Gabrieli; P. Williamson; C. Windischberger; Y.-F. Zang; H.-Y. Zhang; F. X. Castellanos; M. P. Milham

2010-01-01

44

On development of functional brain connectivity in the young brain  

PubMed Central

Our brain is a complex network of structurally and functionally interconnected regions, shaped to efficiently process and integrate information. The development from a brain equipped with basic functionalities to an efficient network facilitating complex behavior starts during gestation and continues into adulthood. Resting-state functional MRI (rs-fMRI) enables the examination of developmental aspects of functional connectivity (FC) and functional brain networks. This review will discuss changes observed in the developing brain on the level of network FC from a gestational age of 20 weeks onwards. We discuss findings of resting-state fMRI studies showing that functional network development starts during gestation, creating a foundation for each of the resting-state networks (RSNs) to be established. Visual and sensorimotor areas are reported to develop first, with other networks, at different rates, increasing both in network connectivity and size over time. Reaching childhood, marked fine-tuning and specialization takes place in the regions necessary for higher-order cognitive functions. PMID:24115929

Hoff, G. E. Anna-Jasmijn; Van den Heuvel, M. P.; Benders, Manon J. N. L.; Kersbergen, Karina J.; De Vries, L. S.

2013-01-01

45

Functional connectivity hubs in the human brain  

Microsoft Academic Search

Brain networks appear to have few and well localized regions with high functional connectivity density (hubs) for fast integration of neural processing, and their dysfunction could contribute to neuropsychiatric diseases. However the variability in the distribution of these brain hubs is unknown due in part to the overwhelming computational demands associated to their localization. Recently we developed a fast algorithm

Dardo Tomasi; Nora D. Volkow

2011-01-01

46

Project X functional requirements specification  

SciTech Connect

Project X is a multi-megawatt proton facility being developed to support intensity frontier research in elementary particle physics, with possible applications to nuclear physics and nuclear energy research, at Fermilab. A Functional Requirements Specification has been developed in order to establish performance criteria for the Project X complex in support of these multiple missions. This paper will describe the Functional Requirements for the Project X facility and the rationale for these requirements.

Holmes, S.D.; Henderson, S.D.; Kephart, R.; Kerby, J.; Mishra, S.; Nagaitsev, S.; Tschirhart, R.; /Fermilab

2011-03-01

47

Computational role of disinhibition in brain function  

E-print Network

Neurons are connected to form functional networks in the brain. When neurons are combined in sequence, nontrivial effects arise. One example is disinhibition; that is, inhibition to another inhibitory factor. Disinhibition may be serving...

Yu, Yingwei

2009-06-02

48

Structure and function of gap junctions in the developing brain  

Microsoft Academic Search

Gap-junction-dependent neuronal communication is widespread in the developing brain, and the prevalence of gap-junctional coupling is well correlated with specific developmental events. We summarize here our current knowledge of the contribution of gap junctions to brain development and propose that they carry out this role by taking advantage of the full complement of their functional properties. Thus, hemichannel activation may

Roberto Bruzzone; Rolf Dermietzel

2006-01-01

49

Functional brain development in humans  

Microsoft Academic Search

There is a continuing debate in developmental neuroscience about the importance of activity-dependent processes. The relatively delayed rate of development of the human brain, compared with that of other mammals, might make it more susceptible to the influence of postnatal experience. The human infant is well adapted to capitalize on this opportunity through primitive biases to attend to relevant stimuli

Mark H. Johnson

2001-01-01

50

Structural and Functional Brain Abnormalities in Schizophrenia  

PubMed Central

Schizophrenia is associated with changes in the structure and functioning of a number of key brain systems, including prefrontal and medial temporal lobe regions involved in working memory and declarative memory, respectively. Imaging techniques provide an unparalleled window into these changes, allowing repeated assessments across pre- and post-onset stages of the disorder and in relation to critical periods of brain development. Here we review recent directions in structural and functional neuroimaging research on schizophrenia. The view emerging from this work is that schizophrenia is fundamentally a disorder of disrupted neural connectivity, the sources of which appear to be genetic and environmental risk factors influencing brain development both prenatally and during adolescence.

Karlsgodt, Katherine H.; Sun, Daqiang; Cannon, Tyrone D.

2014-01-01

51

Degree of musical expertise modulates higher order brain functioning.  

PubMed

Using functional magnetic resonance imaging, we show for the first time that levels of musical expertise stepwise modulate higher order brain functioning. This suggests that degree of training intensity drives such cerebral plasticity. Participants (non-musicians, amateurs, and expert musicians) listened to a comprehensive set of specifically composed string quartets with hierarchically manipulated endings. In particular, we implemented 2 irregularities at musical closure that differed in salience but were both within the tonality of the piece (in-key). Behavioral sensitivity scores (d') of both transgressions perfectly separated participants according to their level of musical expertise. By contrasting brain responses to harmonic transgressions against regular endings, functional brain imaging data showed compelling evidence for stepwise modulation of brain responses by both violation strength and expertise level in a fronto-temporal network hosting universal functions of working memory and attention. Additional independent testing evidenced an advantage in visual working memory for the professionals, which could be predicted by musical training intensity. The here introduced findings of brain plasticity demonstrate the progressive impact of musical training on cognitive brain functions that may manifest well beyond the field of music processing. PMID:22832388

Oechslin, Mathias S; Van De Ville, Dimitri; Lazeyras, François; Hauert, Claude-Alain; James, Clara E

2013-09-01

52

BrainKnowledge: A Human Brain Function Mapping Knowledge-Base System  

E-print Network

BrainKnowledge: A Human Brain Function Mapping Knowledge-Base System Mei-Yu Hsiao & Chien and interpretation of fMRI data. Here, we present a human brain function mapping knowledge-base system (BrainKnowledge) that associates fMRI data analysis and literature search func- tions. BrainKnowledge not only contains indexed

Chen, Chein Chung

53

Detecting disease-specific patterns of brain structure using cortical pattern matching and a population-based probabilistic brain atlas  

PubMed Central

The rapid creation of comprehensive brain image databases mandates the development of mathematical algorithms to uncover disease specific patterns of brain structure and function in human populations. We describe our construction of probabilistic atlases that store detailed information on how the brain varies across age and gender, across time, in health and disease, and in large human populations. Specifically, we introduce a mathematical framework based on covariant partial differential equations (PDEs), pull-backs of mappings under harmonic flows, and high-dimensional random tensor fields to encode variations in cortical patterning, asymmetry and tissue distribution in a population-based brain image database (N =94 scans). We use this information to detect disease-specific abnormalities in Alzheimer's disease and schizophrenia, including dynamic changes over time. Illustrative examples are chosen to show how group patterns of cortical organization, asymmetry, and disease-specific trends can be resolved that are not apparent in individual brain images. Finally, we create four-dimensional (4D) maps that store probabilistic information on the dynamics of brain change in development and disease. Digital atlases that generate these maps show considerable promise in identifying general patterns of structural and functional variation in diseased populations, and revealing how these features depend on demographic, genetic, clinical and therapeutic parameters. PMID:21218175

Thompson, Paul M.; Mega, Michael S.; Vidal, Christine; Rapoport, Judith L.; Toga, Arthur W.

2008-01-01

54

Progesterone Receptors: Form and Function in Brain  

PubMed Central

Emerging data indicate that progesterone has multiple non-reproductive functions in the central nervous system to regulate cognition, mood, inflammation, mitochondrial function, neurogenesis and regeneration, myelination and recovery from traumatic brain injury. Progesterone-regulated neural responses are mediated by an array of progesterone receptors (PR) that include the classic nuclear PRA and PRB receptors and splice variants of each, the seven transmembrane domain 7TMPR? and the membrane-associated 25-Dx PR (PGRMC1). These PRs induce classic regulation of gene expression while also transducing signaling cascades that originate at the cell membrane and ultimately activate transcription factors. Remarkably, PRs are broadly expressed throughout the brain and can be detected in every neural cell type. The distribution of PRs beyond hypothalamic borders, suggests a much broader role of progesterone in regulating neural function. Despite the large body of evidence regarding progesterone regulation of reproductive behaviors and estrogen-inducible responses as well as effects of progesterone metabolite neurosteroids, much remains to be discovered regarding the functional outcomes resulting from activation of the complex array of PRs in brain by gonadally and / or glial derived progesterone. Moreover, the impact of clinically used progestogens and developing selective PR modulators for targeted outcomes in brain is a critical avenue of investigation as the non-reproductive functions of PRs have far-reaching implications for hormone therapy to maintain neurological health and function throughout menopausal aging. PMID:18374402

Brinton, Roberta Diaz; Thompson, Richard F.; Foy, Michael R.; Baudry, Michel; Wang, JunMing; Finch, Caleb E; Morgan, Todd E.; Stanczyk, Frank Z.; Pike, Christian J.; Nilsen, Jon

2008-01-01

55

Optogenetic approaches for functional mouse brain mapping  

PubMed Central

To better understand the connectivity of the brain, it is important to map both structural and functional connections between neurons and cortical regions. In recent years, a set of optogenetic tools have been developed that permit selective manipulation and investigation of neural systems. These tools have enabled the mapping of functional connections between stimulated cortical targets and other brain regions. Advantages of the approach include the ability to arbitrarily stimulate brain regions that express opsins, allowing for brain mapping independent of behavior or sensory processing. The ability of opsins to be rapidly and locally activated allows for investigation of connectivity with spatial resolution on the order of single neurons and temporal resolution on the order of milliseconds. Optogenetic methods for functional mapping have been applied in experiments ranging from in vitro investigation of microcircuits, to in vivo probing of inter-regional cortical connections, to examination of global connections within the whole brain. We review recently developed functional mapping methods that use optogenetic single-point stimulation in the rodent brain and employ cellular electrophysiology, evoked motor movements, voltage sensitive dyes (VSDs), calcium indicators, or functional magnetic resonance imaging (fMRI) to assess activity. In particular we highlight results using red-shifted organic VSDs that permit high temporal resolution imaging in a manner spectrally separated from Channelrhodopsin-2 (ChR2) activation. VSD maps stimulated by ChR2 were dependent on intracortical synaptic activity and were able to reflect circuits used for sensory processing. Although the methods reviewed are powerful, challenges remain with respect to finding approaches that permit selective high temporal resolution assessment of stimulated activity in animals that can be followed longitudinally. PMID:23596383

Lim, Diana H.; LeDue, Jeffrey; Mohajerani, Majid H.; Vanni, Matthieu P.; Murphy, Timothy H.

2013-01-01

56

Beyond genotype: serotonin transporter epigenetic modification predicts human brain function.  

PubMed

We examined epigenetic regulation in regards to behaviorally and clinically relevant human brain function. Specifically, we found that increased promoter methylation of the serotonin transporter gene predicted increased threat-related amygdala reactivity and decreased mRNA expression in postmortem amygdala tissue. These patterns were independent of functional genetic variation in the same region. Furthermore, the association with amygdala reactivity was replicated in a second cohort and was robust to both sampling methods and age. PMID:25086606

Nikolova, Yuliya S; Koenen, Karestan C; Galea, Sandro; Wang, Chiou-Miin; Seney, Marianne L; Sibille, Etienne; Williamson, Douglas E; Hariri, Ahmad R

2014-09-01

57

28 CFR 0.76 - Specific functions.  

Code of Federal Regulations, 2010 CFR

...2010-07-01 2010-07-01 false Specific functions. 0.76 Section 0.76 Judicial Administration...Justice Management Division § 0.76 Specific functions. The functions delegated to the Assistant Attorney General...

2010-07-01

58

Press Release Fingerprints of higher brain functions  

E-print Network

Seite 1/3 Press Release Fingerprints of higher brain functions Neuroscientists uncover novel during information processing, may be `fingerprints' of these basic calculations. Such basic calculations of brainwaves, also known as oscillations, are `spec- tral fingerprints' of canonical neuronal computations

Tübingen, Universität

59

Dissociations between behavioural and functional magnetic resonance imaging-based evaluations of cognitive function after brain injury  

PubMed Central

Functional neuroimaging methods hold promise for the identification of cognitive function and communication capacity in some severely brain-injured patients who may not retain sufficient motor function to demonstrate their abilities. We studied seven severely brain-injured patients and a control group of 14 subjects using a novel hierarchical functional magnetic resonance imaging assessment utilizing mental imagery responses. Whereas the control group showed consistent and accurate (for communication) blood-oxygen-level-dependent responses without exception, the brain-injured subjects showed a wide variation in the correlation of blood-oxygen-level-dependent responses and overt behavioural responses. Specifically, the brain-injured subjects dissociated bedside and functional magnetic resonance imaging-based command following and communication capabilities. These observations reveal significant challenges in developing validated functional magnetic resonance imaging-based methods for clinical use and raise interesting questions about underlying brain function assayed using these methods in brain-injured subjects. PMID:21354974

Bardin, Jonathan C.; Fins, Joseph J.; Katz, Douglas I.; Hersh, Jennifer; Heier, Linda A.; Tabelow, Karsten; Dyke, Jonathan P.; Ballon, Douglas J.; Schiff, Nicholas D.

2011-01-01

60

Hemispheric asymmetry of electroencephalography-based functional brain networks.  

PubMed

Electroencephalography (EEG)-based functional brain networks have been investigated frequently in health and disease. It has been shown that a number of graph theory metrics are disrupted in brain disorders. EEG-based brain networks are often studied in the whole-brain framework, where all the nodes are grouped into a single network. In this study, we studied the brain networks in two hemispheres and assessed whether there are any hemispheric-specific patterns in the properties of the networks. To this end, resting state closed-eyes EEGs from 44 healthy individuals were processed and the network structures were extracted separately for each hemisphere. We examined neurophysiologically meaningful graph theory metrics: global and local efficiency measures. The global efficiency did not show any hemispheric asymmetry, whereas the local connectivity showed rightward asymmetry for a range of intermediate density values for the constructed networks. Furthermore, the age of the participants showed significant direct correlations with the global efficiency of the left hemisphere, but only in the right hemisphere, with local connectivity. These results suggest that only local connectivity of EEG-based functional networks is associated with brain hemispheres. PMID:25191924

Jalili, Mahdi

2014-11-12

61

Brain imaging methods used in experimental brain research such as Positron Emission Tomography (PET) and Functional  

E-print Network

ABSTRACT Brain imaging methods used in experimental brain research such as Positron Emission and are best understood in the context of the underlying 3D brain anatomy. In this paper, we present a novel Brain Mapping, Functional Imaging 1 INTRODUCTION Although the human brain is no longer the black box

Mueller, Klaus

62

Homological scaffolds of brain functional networks.  

PubMed

Networks, as efficient representations of complex systems, have appealed to scientists for a long time and now permeate many areas of science, including neuroimaging (Bullmore and Sporns 2009 Nat. Rev. Neurosci. 10, 186-198. (doi:10.1038/nrn2618)). Traditionally, the structure of complex networks has been studied through their statistical properties and metrics concerned with node and link properties, e.g. degree-distribution, node centrality and modularity. Here, we study the characteristics of functional brain networks at the mesoscopic level from a novel perspective that highlights the role of inhomogeneities in the fabric of functional connections. This can be done by focusing on the features of a set of topological objects-homological cycles-associated with the weighted functional network. We leverage the detected topological information to define the homological scaffolds, a new set of objects designed to represent compactly the homological features of the correlation network and simultaneously make their homological properties amenable to networks theoretical methods. As a proof of principle,we apply these tools to compare resting state functional brain activity in 15 healthy volunteers after intravenous infusion of placebo and psilocybin-the main psychoactive component of magic mushrooms. The results show that the homological structure of the brain's functional patterns undergoes a dramatic change post-psilocybin, characterized by the appearance of many transient structures of low stability and of a small number of persistent ones that are not observed in the case of placebo. PMID:25401177

Petri, G; Expert, P; Turkheimer, F; Carhart-Harris, R; Nutt, D; Hellyer, P J; Vaccarino, F

2014-12-01

63

Electroencephalographic imaging of higher brain function.  

PubMed Central

High temporal resolution is necessary to resolve the rapidly changing patterns of brain activity that underlie mental function. Electroencephalography (EEG) provides temporal resolution in the millisecond range. However, traditional EEG technology and practice provide insufficient spatial detail to identify relationships between brain electrical events and structures and functions visualized by magnetic resonance imaging or positron emission tomography. Recent advances help to overcome this problem by recording EEGs from more electrodes, by registering EEG data with anatomical images, and by correcting the distortion caused by volume conduction of EEG signals through the skull and scalp. In addition, statistical measurements of sub-second interdependences between EEG time-series recorded from different locations can help to generate hypotheses about the instantaneous functional networks that form between different cortical regions during perception, thought and action. Example applications are presented from studies of language, attention and working memory. Along with its unique ability to monitor brain function as people perform everyday activities in the real world, these advances make modern EEG an invaluable complement to other functional neuroimaging modalities. PMID:10466140

Gevins, A; Smith, M E; McEvoy, L K; Leong, H; Le, J

1999-01-01

64

Structural and functional neuroimaging studies of the suicidal brain  

Microsoft Academic Search

Suicidality is a major challenge for today's health care. Evidence suggests that there are differences in cognitive functioning of suicidal patients but the knowledge about the underlying neurobiology is limited. Brain imaging offers the advantage of a non-invasive in vivo direct estimation of detailed brain structure, regional brain functioning and estimation of molecular processes in the brain.We have reviewed the

S. Desmyter; C. van Heeringen; K. Audenaert

2011-01-01

65

Encoding and Retrieving Faces and Places: Distinguishing Process- and Stimulus-Specific Differences in Brain Activity  

ERIC Educational Resources Information Center

Among the most fundamental issues in cognitive neuroscience is how the brain may be organized into process-specific and stimulus-specific regions. In the episodic memory domain, most functional neuroimaging studies have focused on the former dimension, typically investigating the neural correlates of various memory processes. Thus, there is little…

Prince, Steven E.; Dennis, Nancy A.; Cabeza, Roberto

2009-01-01

66

Behavioral/Systems/Cognitive Chronic Pain and the Emotional Brain: Specific Brain  

E-print Network

Behavioral/Systems/Cognitive Chronic Pain and the Emotional Brain: Specific Brain Activity of Chicago, Lurie Cancer Center, Northwestern University, Feinberg School of Medicine, Chicago, Illinois,yetthereisalackofknowledgeregardingbrainelementsinvolvedinsuchconditions.Here,weidentifybrainregionsinvolvedin spontaneous pain of chronic back pain (CBP) in two separate groups of patients (n 13 and n 11), and contrast

Apkarian, A. Vania

67

Retinoic Acid Signaling in the Functioning Brain  

NSDL National Science Digital Library

Retinoic acid, an active form of vitamin A, regulates gene expression throughout the body, and many components of the signaling system through which it acts are present in the brain. Very little is known, however, about how retinoic acid functions in neurobiological systems. Several studies have provided evidence that retinoic acid plays a role in sleep, learning, and memory, but the precise mechanisms through which it influences these processes remain unclear. All of these processes involve local or long-range inhibition and synchronized neuronal activity between separate locations in the brain. A critical component in the generation of the synchronized firing of cortical neurons (cortical synchrony) is a network of inhibitory interneurons containing parvalbumin, a cell population affected by retinoid perturbations, such as exposure to a vitamin A overdose. An understanding of the role of retinoids in normal brain function would provide clues to the long-standing question of whether abnormalities in retinoic acid signaling contribute to the pathogenesis of some brain diseases with uncertain etiologies that involve both genetic and environmental factors.

Ursula C. Drager (University of Massachusetts Medical School;Eunice Kennedy Shriver Center REV)

2006-02-28

68

Chemical basis for brain-specific serine transfer RNAs.  

PubMed Central

Serine tRNA from rat brain can be resolved into six isoaccepting species. Three of these species show the same chromatographic behavior as the seryl tRNAs from other rat organs, whereas the remaining species appear to be specific for brain. The isoacceptor tRNAs were purified to homogeneity by chromatography on benzoylated DEAE-cellulose followed by reversed-phase chromatography. We found that the additional species of serine tRNA in brain differ from their counterparts derived from other rat organs by a lack of a specific guanosine ribose-methylation in the dihydrouridine loop. In addition, when total liver tRNA was compared with total brain tRNA, the same degree of undermethylation with respect to 2'-O-methylguanosine was found as a general phenomenon. Images PMID:270667

Rogg, H; Müller, P; Keith, G; Staehelin, M

1977-01-01

69

The functional significance of brain metallothioneins  

Microsoft Academic Search

Metallothioneins (MTs) are ubiquitous low molecular weight proteins characterized by their abundant content of cysteines. Two MT isoforms, MT-I and MT-lI, are expressed coordinately in all mammalian tissues. In the CNS, MT-I and MT-I! are conspicuously absent from neuronal populations, yet abundant in fibrous and protoplasmic astrocytes. A newly identified brain-specific MT gene, MT-Ill, is predominantly expressed in zinc-containing neurons

MICHAEL ASCHNER

70

The formation and function of the brain ventricular system  

E-print Network

The brain ventricular system is composed of a highly conserved set of cavities that contain cerebrospinal fluid (CSF), a protein-rich fluid essential for brain function. However, little is known about the function of ...

Chang, Jessica T. (Jessica Tzung-Min)

2012-01-01

71

Brain Function Lateralization and Language Acquisition: the Evidence from Japanese.  

ERIC Educational Resources Information Center

Presents evidence of differences in brain function lateralization between Japanese-speakers and speakers of Indo-European languages, and suggests that current conceptualizations of brain function specialization are not adequate. (AM)

Sanches, Mary

1979-01-01

72

When "altering brain function" becomes "mind control"  

PubMed Central

Functional neurosurgery has seen a resurgence of interest in surgical treatments for psychiatric illness. Deep brain stimulation (DBS) technology is the preferred tool in the current wave of clinical experiments because it allows clinicians to directly alter the functions of targeted brain regions, in a reversible manner, with the intent of correcting diseases of the mind, such as depression, addiction, anorexia nervosa, dementia, and obsessive compulsive disorder. These promising treatments raise a critical philosophical and humanitarian question. “Under what conditions does ‘altering brain function’ qualify as ‘mind control’?” In order to answer this question one needs a definition of mind control. To this end, we reviewed the relevant philosophical, ethical, and neurosurgical literature in order to create a set of criteria for what constitutes mind control in the context of DBS. We also outline clinical implications of these criteria. Finally, we demonstrate the relevance of the proposed criteria by focusing especially on serendipitous treatments involving DBS, i.e., cases in which an unintended therapeutic benefit occurred. These cases highlight the importance of gaining the consent of the subject for the new therapy in order to avoid committing an act of mind control.

Koivuniemi, Andrew; Otto, Kevin

2014-01-01

73

Common and specific brain responses to scenic emotional stimuli.  

PubMed

Processing of emotions has been an enduring topic of interest in neuroimaging research, but studies have mostly used facial emotional stimuli. The aim of this study was to determine neural networks involved in emotion processing using scenic emotional visual stimuli. One hundred and twenty photographs from the International Affective Picture System (IAPS), including ecological scenes of disgust, fear, happiness, and sadness, were presented to 40 healthy participants while they underwent functional magnetic imaging resonance (fMRI). Afterwards they evaluated the emotional content of the pictures in an offline task. The occipito-temporal cortex and the amygdala-hippocampal complex showed a non-specific emotion-related activation, which was more marked in response to negative emotions than to happiness. The temporo-parietal cortex and the ventral anterior cingulate gyrus showed deactivation, with the former being marked for all emotions except fear and the latter being most marked for disgust. The fusiform gyrus showed activation in response to disgust and deactivation in response to happiness or sadness. Brain regions involved in processing of scenic emotion therefore resemble those reported for facial expressions of emotion in that they respond to a range of different emotions, although there appears to be specificity in the intensity and direction of the response. PMID:23700105

Radua, Joaquim; Sarró, Salvador; Vigo, Teresa; Alonso-Lana, Silvia; Bonnín, C Mar; Ortiz-Gil, Jordi; Canales-Rodríguez, Erick J; Maristany, Teresa; Vieta, Eduard; Mckenna, Peter J; Salvador, Raymond; Pomarol-Clotet, Edith

2014-07-01

74

Impacts of Brain Serotonin Deficiency following Tph2 Inactivation on Development and Raphe Neuron Serotonergic Specification  

PubMed Central

Brain serotonin (5-HT) is implicated in a wide range of functions from basic physiological mechanisms to complex behaviors, including neuropsychiatric conditions, as well as in developmental processes. Increasing evidence links 5-HT signaling alterations during development to emotional dysregulation and psychopathology in adult age. To further analyze the importance of brain 5-HT in somatic and brain development and function, and more specifically differentiation and specification of the serotonergic system itself, we generated a mouse model with brain-specific 5-HT deficiency resulting from a genetically driven constitutive inactivation of neuronal tryptophan hydroxylase-2 (Tph2). Tph2 inactivation (Tph2?/?) resulted in brain 5-HT deficiency leading to growth retardation and persistent leanness, whereas a sex- and age-dependent increase in body weight was observed in Tph2+/? mice. The conserved expression pattern of the 5-HT neuron-specific markers (except Tph2 and 5-HT) demonstrates that brain 5-HT synthesis is not a prerequisite for the proliferation, differentiation and survival of raphe neurons subjected to the developmental program of serotonergic specification. Furthermore, although these neurons are unable to synthesize 5-HT from the precursor tryptophan, they still display electrophysiological properties characteristic of 5-HT neurons. Moreover, 5-HT deficiency induces an up-regulation of 5-HT1A and 5-HT1B receptors across brain regions as well as a reduction of norepinephrine concentrations accompanied by a reduced number of noradrenergic neurons. Together, our results characterize developmental, neurochemical, neurobiological and electrophysiological consequences of brain-specific 5-HT deficiency, reveal a dual dose-dependent role of 5-HT in body weight regulation and show that differentiation of serotonergic neuron phenotype is independent from endogenous 5-HT synthesis. PMID:22912815

Gutknecht, Lise; Araragi, Naozumi; Merker, Soren; Waider, Jonas; Sommerlandt, Frank M. J.; Mlinar, Boris; Baccini, Gilda; Mayer, Ute; Proft, Florian; Hamon, Michel; Schmitt, Angelika G.; Corradetti, Renato; Lanfumey, Laurence; Lesch, Klaus-Peter

2012-01-01

75

Split My Brain: A Case Study of Seizure Disorder and Brain Function  

ERIC Educational Resources Information Center

This case involves a couple deciding whether or not their son should undergo brain surgery to treat a severe seizure disorder. In examining this dilemma, students apply knowledge of brain anatomy and function. They also learn about brain scanning techniques and discuss the plasticity of the brain.

Omarzu, Julia

2004-01-01

76

Age-related reorganizational changes in modularity and functional connectivity of human brain networks.  

PubMed

Abstract The human brain undergoes both morphological and functional modifications across the human lifespan. It is important to understand the aspects of brain reorganization that are critical in normal aging. To address this question, one approach is to investigate age-related topological changes of the brain. In this study, we developed a brain network model using graph theory methods applied to the resting-state functional magnetic resonance imaging data acquired from two groups of normal healthy adults classified by age. We found that brain functional networks demonstrated modular organization in both groups with modularity decreased with aging, suggesting less distinct functional divisions across whole brain networks. Local efficiency was also decreased with aging but not with global efficiency. Besides these brain-wide observations, we also observed consistent alterations of network properties at the regional level in the elderly, particularly in two major functional networks-the default mode network (DMN) and the sensorimotor network. Specifically, we found that measures of regional strength, local and global efficiency of functional connectivity were increased in the sensorimotor network while decreased in the DMN with aging. These results indicate that global reorganization of brain functional networks may reflect overall topological changes with aging and that aging likely alters individual brain networks differently depending on the functional properties. Moreover, these findings highly correspond to the observation of decline in cognitive functions but maintenance of primary information processing in normal healthy aging, implying an underlying compensation mechanism evolving with aging to support higher-level cognitive functioning. PMID:25183440

Song, Jie; Birn, Rasmus M; Boly, Mélanie; Meier, Timothy B; Nair, Veena A; Meyerand, Mary E; Prabhakaran, Vivek

2014-11-01

77

Visualization of specific binding sites of benzodiazepine in human brain  

SciTech Connect

Using 11C-labeled Ro15-1788 and positron emission tomography, studies of benzodiazepine binding sites in the human brain were performed on four normal volunteers. Rapid and high accumulation of 11C activity was observed in the brain after i.v. injection of (11C)Ro15-1788, the maximum of which was within 12 min. Initial distribution of 11C activity in the brain was similar to the distribution of the normal cerebral blood flow. Ten minutes after injection, however, a high uptake of 11C activity was observed in the cerebral cortex and moderate uptake was seen in the cerebellar cortex, the basal ganglia, and the thalamus. The accumulation of 11C activity was low in the brain stem. This distribution of 11C activity was approximately parallel to the known distribution of benzodiazepine receptors. Saturation experiments were performed on four volunteers with oral administration of 0.3-1.8 mg/kg of cold Ro15-1788 prior to injection. Initial distribution of 11C activity following injection peaked within 2 min and then the accumulation of 11C activity decreased rapidly and remarkably throughout the brain. The results indicated that (11C) Ro15-1788 associates and dissociates to specific and nonspecific binding sites rapidly and has a high ratio of specific receptor binding to nonspecific binding in vivo. Carbon-11 Ro15-1788 is a suitable radioligand for the study of benzodiazepine receptors in vivo in humans.

Shinotoh, H.; Yamasaki, T.; Inoue, O.; Itoh, T.; Suzuki, K.; Hashimoto, K.; Tateno, Y.; Ikehira, H.

1986-10-01

78

Brain structural and functional correlates of resilience to Bipolar Disorder  

PubMed Central

Background: Resilient adaptation can be construed in different ways, but as used here it refers to adaptive brain responses associated with avoidance of psychopathology despite expressed genetic predisposition to Bipolar Disorder (BD). Although family history of BD is associated with elevated risk of affective morbidity a significant proportion of first-degree relatives remain free of psychopathology. Examination of brain structure and function in these individuals may inform on adaptive responses that pre-empt disease expression. Methods: Data presented here are derived from the Vulnerability to Bipolar Disorders Study (VIBES) which includes BD patients, asymptomatic relatives and controls. Participants underwent extensive investigations including brain structural (sMRI) and functional magnetic resonance imaging (fMRI). We present results from sMRI voxel-based-morphometry and from conventional and connectivity analyses of fMRI data obtained during the Stroop Colour Word Test (SCWT), a task of cognitive control during conflict resolution. All analyses were implemented using Statistical Parametric Mapping software version 5 (SPM5). Resilience in relatives was operationalized as the lifetime absence of clinical-range symptoms. Results: Resilient relatives of BD patients expressed structural, functional, and connectivity changes reflecting the effect of genetic risk on the brain. These included increased insular volume, decreased activation within the posterior and inferior parietal regions involved in selective attention during the SCWT, and reduced fronto-insular and fronto-cingulate connectivity. Resilience was associated with increased cerebellar vermal volume and enhanced functional coupling between the dorsal and the ventral prefrontal cortex during the SCWT. Conclusions: Our findings suggests the presence of biological mechanisms associated with resilient adaptation of brain networks and pave the way for the identification of outcome-specific trajectories given a bipolar genotype. PMID:22363273

Frangou, Sophia

2011-01-01

79

Functional Geometry Alignment and Localization of Brain Areas  

E-print Network

Functional Geometry Alignment and Localization of Brain Areas Georg Langs, Polina Golland Computer@bwh.harvard.edu, lrigolo@bwh.harvard.edu agolby@bwh.harvard.edu Abstract Matching functional brain regions across. It is particularly difficult, but highly relevant, for patients with pathologies such as brain tumors, which can

Golland, Polina

80

Noninvasive Functional Brain Mapping Using Registered Transcranial Magnetic Stimulation  

E-print Network

Non­invasive Functional Brain Mapping Using Registered Transcranial Magnetic Stimulation G Brain Mapping Using Registered Transcranial Magnetic Stimulation January 22, 1996 Abstract We describe the functional regions of the brain using a tran­ scranial magnetic stimulation (TMS) device. This device, when

81

Computational Modeling of High-Level Cognition and Brain Function  

E-print Network

Computational Modeling of High-Level Cognition and Brain Function Marcel Adam Just,* Patricia A. Carpenter, and Sashank Varma Center for Cognitive Brain Imaging, Carnegie Mellon University, Pittsburgh key properties of cortical function into the design of the modeling system. Hum. Brain Mapping 8

82

Localization of asymmetric brain function in emotion and depression.  

PubMed

Although numerous EEG studies have shown that depression is associated with abnormal functional asymmetries in frontal cortex, fMRI and PET studies have largely failed to identify specific brain areas showing this effect. The present study tested the hypothesis that emotion processes are related to asymmetric patterns of fMRI activity, particularly within dorsolateral prefrontal cortex (DLPFC). Eleven depressed and 18 control participants identified the color in which pleasant, neutral, and unpleasant words were printed. Both groups showed a leftward lateralization for pleasant words in DLPFC. In a neighboring DLPFC area, the depression group showed more right-lateralized activation than controls, replicating EEG findings. These data confirm that emotional stimulus processing and trait depression are associated with asymmetric brain functions in distinct subregions of the DLPFC that may go undetected unless appropriate analytic procedures are used. PMID:20070577

Herrington, John D; Heller, Wendy; Mohanty, Aprajita; Engels, Anna S; Banich, Marie T; Webb, Andrew G; Miller, Gregory A

2010-05-01

83

Simple sequence in brain and nervous system specific proteins  

Microsoft Academic Search

We examined sequences expressed in the brain and nervous system using EST data. A previous study in- cluding sequences thought to have neurological function found a deficiency of simple sequence within such sequences. This was despite many examples of neurodegenerative diseases, such as Huntington disease, which are thought to be caused by expansions of polyglutamine tracts within associated protein sequences.

Melanie A. Huntley; Sanaa Mahmood; G. Brian Golding

84

Violent Video Games Alter Brain Function in Young Men  

MedlinePLUS

... the RSNA Annual Meeting November 30, 2011 Violent Video Games Alter Brain Function in Young Men CHICAGO— ... fMRI) analysis of long-term effects of violent video game play on the brain has found changes ...

85

Functional organization of the transcriptome in human brain  

Microsoft Academic Search

The enormous complexity of the human brain ultimately derives from a finite set of molecular instructions encoded in the human genome. These instructions can be directly studied by exploring the organization of the brain's transcriptome through systematic analysis of gene coexpression relationships. We analyzed gene coexpression relationships in microarray data generated from specific human brain regions and identified modules of

Genevieve Konopka; Kazuya Iwamoto; Peter Langfelder; Tadafumi Kato; Steve Horvath; Michael C Oldham; Daniel H Geschwind

2008-01-01

86

Executive functions and social skills in survivors of pediatric brain tumor  

Microsoft Academic Search

Medical advances have resulted in increased survival rates for children with brain tumors. Consequently, issues related to survivorship have become more critical. The use of multimodal treatment, in particular cranial radiation therapy, has been associated with subsequent cognitive decline. Specifically, deficits in executive functions have been reported in survivors of various types of pediatric brain tumor. Survivors are left with

Kelly R. Wolfe; Karin S. Walsh; Nina C. Reynolds; Frances Mitchell; Alyssa T. Reddy; Iris Paltin; Avi Madan-Swain

2012-01-01

87

Searching for a baseline: Functional imaging and the resting human brain  

Microsoft Academic Search

Functional brain imaging in humans has revealed task-specific increases in brain activity that are associated with various mental activities. In the same studies, mysterious, task-independent decreases have also frequently been encountered, especially when the tasks of interest have been compared with a passive state, such as simple fixation or eyes closed. These decreases have raised the possibility that there might

Debra A. Gusnard; Marcus E. Raichle

2001-01-01

88

Ivermectin excretion by isolated functionally intact brain endothelial capillaries  

PubMed Central

Functionally intact brain endothelial capillaries were isolated from porcine brain. p-Glycoprotein was localized at the lumenal membrane of intact capillaries by immunohistochemistry using a murine monoclonal antibody and a secondary FITC fluorescent labelled anti-mouse IgG. Western blot staining of p-glycoprotein in isolated endothelial cells confirmed the immunohistochemistry. Excretion of the fluorescent labelled anthelmintic drug Ivermectin (BODIPY-Ivermectin) was studied in the isolated brain endothelial capillaries. Drug accumulation in the capillary lumen was visualized by fluorescence confocal laser scanning microscopy and was measured by image analysis. Secretion of BODIPY-Ivermectin into the capillary lumen exhibited characteristics of specific and energy-dependent transport. Steady state lumenal fluorescence intensity averaged 1.6 times cellular fluorescence and was reduced 3?–?4 times below cellular levels when metabolism was inhibited by NaCN. BODIPY-Ivermectin secretion was inhibited in a concentration-dependent manner by unlabeled Ivermectin. In addition, lumenal but not cellular fluorescence intensity was significantly decreased when capillaries were incubated with PSC-833, Cyclosporin A or Verapamil, all inhibitors of p-glycoprotein. Conversely, unlabelled Ivermectin reduced the p-glycoprotein (Pgp)-mediated secretion of a fluorescent derivative of Verapamil, (BODIPY-Verapamil). BODIPY-Ivermectin secretion was not affected in the presence of Leucotriene C4 (LTC4), a potent inhibitor of multidrug resistance related protein (mrp)-mediated transport processes. In addition, excretion of Fluorescein-Methotrexate, an mrp-substrate, was not inhibited by Ivermectin. Uptake experiments with isolated porcine brain capillary cells showing increased cellular uptake of BODIPY-Ivermectin in the presence of unlabelled drug or PSC-833 supported the findings of a Pgp interaction in intact capillaries. The data are consistent with BODIPY-Ivermectin and Ivermectin being transported across the lumenal membrane of brain capillaries. For the first time Pgp-interaction of Ivermectin at the blood brain barrier is demonstrated on a cellular level in an intact vascular tissue. PMID:11159725

Nobmann, Stephanie; Bauer, Bjorn; Fricker, Gert

2001-01-01

89

Specific and Evolving Resting-State Network Alterations in Post-Concussion Syndrome Following Mild Traumatic Brain Injury  

PubMed Central

Post-concussion syndrome has been related to axonal damage in patients with mild traumatic brain injury, but little is known about the consequences of injury on brain networks. In the present study, our aim was to characterize changes in functional brain networks following mild traumatic brain injury in patients with post-concussion syndrome using resting-state functional magnetic resonance imaging data. We investigated 17 injured patients with persistent post-concussion syndrome (under the DSM-IV criteria) at 6 months post-injury compared with 38 mild traumatic brain injury patients with no post-concussion syndrome and 34 healthy controls. All patients underwent magnetic resonance imaging examinations at the subacute (1–3 weeks) and late (6 months) phases after injury. Group-wise differences in functional brain networks were analyzed using graph theory measures. Patterns of long-range functional networks alterations were found in all mild traumatic brain injury patients. Mild traumatic brain injury patients with post-concussion syndrome had greater alterations than patients without post-concussion syndrome. In patients with post-concussion syndrome, changes specifically affected temporal and thalamic regions predominantly at the subacute stage and frontal regions at the late phase. Our results suggest that the post-concussion syndrome is associated with specific abnormalities in functional brain network that may contribute to explain deficits typically observed in PCS patients. PMID:23755237

Messe, Arnaud; Caplain, Sophie; Pelegrini-Issac, Melanie; Blancho, Sophie; Levy, Richard; Aghakhani, Nozar; Montreuil, Michele; Benali, Habib; Lehericy, Stephane

2013-01-01

90

Interaction of functionalized superparamagnetic iron oxide nanoparticles with brain structures.  

PubMed

Super Paramagnetic Iron Oxide Nanoparticles (SPIONs) combined with magnetic resonance imaging (MRI) are under clinical evaluation to enhance detection of neurodegenerative diseases. A major improvement would be to link therapeutic drugs to the SPIONs to achieve targeted drug delivery, either at the cell surface or intracellularly, together with active disease detection, without inducing cell reaction. Our objectives were to define the characteristics of SPIONS able to achieve cell-specific interaction with brain-derived structures. Our system consisted in an iron oxide core (9-10 nm diameter) coated either with dextran (Sinerem and Endorem) or various functionalized polyvinyl alcohols (PVAs) (PVA-SPIONs). We investigated the cellular uptake, cytotoxicity, and interaction of these various nanoparticles with brain-derived endothelial cells, microglial cells, and differentiating three-dimensional aggregates. None of the nanoparticles coated with dextran or the various PVAs was cytotoxic or induced the production of the inflammatory mediator NO used as a reporter for cell activation. AminoPVA-SPIONs were taken up by isolated brain-derived endothelial and microglial cells at a much higher level than the other SPIONs, and no inflammatory activation of these cells was observed. AminoPVA-SPIONs did not invade brain cells aggregates lower than the first cell layer and did not induce inflammatory reaction in the aggregates. Fluorescent aminoPVA-SPIONs derivatized with a fluorescent reporter molecule and confocal microscopy demonstrated intracellular uptake by microglial cells. Fluorescent aminoPVA-SPIONs were well tolerated by mice. Therefore, functionalized aminoPVA-SPIONs represent biocompatible potential vector systems for drug delivery to the brain that may be combined with MRI detection of active lesions in neurodegenerative diseases. PMID:16608917

Cengelli, Feride; Maysinger, Dusica; Tschudi-Monnet, Florianne; Montet, Xavier; Corot, Claire; Petri-Fink, Alke; Hofmann, Heinrich; Juillerat-Jeanneret, Lucienne

2006-07-01

91

Resilience of human brain functional coactivation networks under thresholding  

E-print Network

Recent studies have demonstrated the existence of community structure and rich club nodes, (i.e., highly interconnected, high degree hub nodes), in human brain functional networks. The cognitive relevance of the detected modules and hubs has also been demonstrated, for both task based and default mode networks, suggesting that the brain self-organizes into patterns of co-activated sets of regions for performing specific tasks or in resting state. In this paper, we report studies on the resilience or robustness of this modular structure: under systematic erosion of connectivity in the network under thresholding, how resilient is the modularity and hub structure? The results show that the network shows show strong resilience properties, with the modularity and hub structure maintaining itself over a large range of connection strengths. Then, at a certain critical threshold that falls very close to 0, the connectivity, the modularity, and hub structure suddenly break down, showing a phase transition like propert...

Sarkar, S; Weng, H

2014-01-01

92

Magnetic Resonance Imaging of Brain Function and Neurochemistry  

E-print Network

Magnetic Resonance Imaging of Brain Function and Neurochemistry KAMIL UGURBIL, DAE-SHIK KIM, TIM ANDERSEN, AND GREGOR ADRIANY Invited Paper In the past decade, magnetic resonance imaging (MRI) research approaches to map brain function. This capability, often referred to as functional magnetic resonance imaging

Duong, Timothy Q.

93

Mapping distributed brain function and networks with diffuse optical tomography  

PubMed Central

Mapping of human brain function has revolutionized systems neuroscience. However, traditional functional neuroimaging by positron emission tomography or functional magnetic resonance imaging cannot be used when applications require portability, or are contraindicated because of ionizing radiation (positron emission tomography) or implanted metal (functional magnetic resonance imaging). Optical neuroimaging offers a non-invasive alternative that is radiation free and compatible with implanted metal and electronic devices (for example, pacemakers). However, optical imaging technology has heretofore lacked the combination of spatial resolution and wide field of view sufficient to map distributed brain functions. Here, we present a high-density diffuse optical tomography imaging array that can map higher-order, distributed brain function. The system was tested by imaging four hierarchical language tasks and multiple resting-state networks including the dorsal attention and default mode networks. Finally, we imaged brain function in patients with Parkinson’s disease and implanted deep brain stimulators that preclude functional magnetic resonance imaging. PMID:25083161

Eggebrecht, Adam T.; Ferradal, Silvina L.; Robichaux-Viehoever, Amy; Hassanpour, Mahlega S.; Dehghani, Hamid; Snyder, Abraham Z.; Hershey, Tamara; Culver, Joseph P.

2014-01-01

94

Mapping distributed brain function and networks with diffuse optical tomography  

NASA Astrophysics Data System (ADS)

Mapping of human brain function has revolutionized systems neuroscience. However, traditional functional neuroimaging by positron emission tomography or functional magnetic resonance imaging cannot be used when applications require portability, or are contraindicated because of ionizing radiation (positron emission tomography) or implanted metal (functional magnetic resonance imaging). Optical neuroimaging offers a non-invasive alternative that is radiation free and compatible with implanted metal and electronic devices (for example, pacemakers). However, optical imaging technology has heretofore lacked the combination of spatial resolution and wide field of view sufficient to map distributed brain functions. Here, we present a high-density diffuse optical tomography imaging array that can map higher-order, distributed brain function. The system was tested by imaging four hierarchical language tasks and multiple resting-state networks including the dorsal attention and default mode networks. Finally, we imaged brain function in patients with Parkinson's disease and implanted deep brain stimulators that preclude functional magnetic resonance imaging.

Eggebrecht, Adam T.; Ferradal, Silvina L.; Robichaux-Viehoever, Amy; Hassanpour, Mahlega S.; Dehghani, Hamid; Snyder, Abraham Z.; Hershey, Tamara; Culver, Joseph P.

2014-06-01

95

Functional MRI of the Brain in Women with Overactive Bladder: Brain Activation During Urinary Urgency  

PubMed Central

Objectives To identify abnormal function of the limbic cortex (LC) in response to urinary urgency among patients with Overactive Bladder (OAB) using brain functional MRI (fMRI) Methods 5 OAB subjects and 5 Controls underwent bladder filling and rated urgency sensations while fMRI measured activation in discrete volumes (voxels) within the brain. Changes in brain activation were related to bladder distension and individual subject’s rating of urgency via multiple regression analysis. Beta weights from regression equations were converted into percent signal change (PSC) for each voxel and PSC compared to the null hypothesis using T-tests. Significance threshold of P<.05 was applied along with a cluster size threshold of.32 ml (5 voxels). Results OAB patients showed increased brain activation in LC, specifically the insula (IN) and Anterior Cingulate Gyrus (ACG), associated with increased urgency. Urgency sensations during low volumes were associated with bilateral IN activation in OAB subjects (7,621 voxels right IN, 4,453 voxels left IN, mean beta weights .018 +/? .014 and .014 +/? .011) Minimal activation was present in Controls (790 voxels right IN, beta weight =.010 +/? .007). Urgency sensations during high volumes were associated with bilateral ACG activation in OAB subjects (2,304 voxels right IN, 5,005 voxels left IN, mean beta weights of 005 +/? .003 and 004+/?.003) without activation in Controls. Conclusions Urinary urgency in patients with OAB is associated with increased activation of the LC. This activation likely represents abnormal processing of sensory input in brain regions associated with emotional response to discomfort. PMID:21399722

Komesu, Yuko M.; Ketai, Loren H.; Mayer, Andrew R.; Teshiba, Terry M.; Rogers, Rebecca G.

2011-01-01

96

Effects of the diet on brain function  

NASA Technical Reports Server (NTRS)

The rates of synthesis by brain neurons of the neurotransmitters serotonin, acetylcholine, and the catecholamines depend on the brain levels of the respective precursor molecules. Brain levels of each precursor are influenced by their blood concentration, and for the amino acid precursors, by the blood levels of other amino acids as well. Since diet readily alters blood concentrations of each of these precursors, it thereby also influences the brain formation of their neutrotransmitter products.

Fernstrom, J. D.

1981-01-01

97

Abnormal structural and functional brain connectivity in gray matter heterotopia  

E-print Network

Purpose:? Periventricular nodular heterotopia (PNH) is a malformation of cortical development associated with epilepsy and dyslexia. Evidence suggests that heterotopic gray matter can be functional in brain malformations ...

Christodoulou, Joanna

98

ScaleScale--free Brain Functional Networksfree Brain Functional Networks victor@imedea.uib.es www.imedea.uib.es/~victor  

E-print Network

ScaleScale--free Brain Functional Networksfree Brain Functional Networks victor@imedea.uib.es wwwPlan Motivation: Networks & Brain How to get functional networks from fMRI Characterization of brain functional) Co-authorship of scientific papers #12;...... and the brainand the brain #12;""In catalogue" cortical

Oro, Daniel

99

Reduced brain functional reserve and altered functional connectivity in patients with multiple sclerosis.  

PubMed

Cognitive dysfunction (affecting particularly attention and working memory) occurs early in patients with multiple sclerosis. Previous studies have focused on identifying potentially adaptive functional reorganization through recruitment of new brain regions that could limit expression of these deficits. However, lesion studies remind us that functional specializations in the brain make certain brain regions necessary for a given task. We therefore have asked whether altered functional interactions between regions normally recruited provide an alternative adaptive mechanism with multiple sclerosis pathology. We used a version of the n-back task to probe working memory in patients with early multiple sclerosis. We applied a functional connectivity analysis to test whether relationships between relative activations in different brain regions change in potentially adaptive ways with multiple sclerosis. We studied 21 patients with relapsing-remitting multiple sclerosis and 16 age- and sex-matched healthy controls with 3T functional MRI. The two groups performed equally well on the task. Task-related activations were found in similar regions for patients and controls. However, patients showed relatively reduced activation in the superior frontal and anterior cingulate gyri (P > 0.01). Patients also showed a variable, but generally substantially smaller increase in activation than healthy controls with greater task complexity, depending on the specific brain region assessed (P < 0.001). Functional connectivity analysis defined further differences not apparent from the univariate contrast of the task-associated activation patterns. Control subjects showed significantly greater correlations between right dorsolateral prefrontal and superior frontal/anterior cingulate activations (P < 0.05). Patients showed correlations between activations in the right and left prefrontal cortices, although this relationship was not significant in healthy controls (P < 0.05). We interpret these results as showing that, while cognitive processing in the task appears to be performed using similar brain regions in patients and controls, the patients have reduced functional reserve for cognition relevant to memory. Functional connectivity analysis suggests that altered inter-hemispheric interactions between dorsal and lateral prefrontal regions may provide an adaptive mechanism that could limit clinical expression of the disease distinct from recruitment of novel processing regions. Together, these results suggest that therapeutic enhancement of the coherence of interactions between brain regions normally recruited (functional enhancement), as well as recruitment of alternative areas or use of complementary cognitive strategies (both forms of adaptive functional change), may limit expression of cognitive impairments in multiple sclerosis. PMID:16251214

Cader, Sarah; Cifelli, Alberto; Abu-Omar, Yasir; Palace, Jacqueline; Matthews, Paul M

2006-02-01

100

Stereotaxic Surgery for Excitotoxic Lesion of Specific Brain Areas in the Adult Rat  

PubMed Central

Many behavioral functions in mammals, including rodents and humans, are mediated principally by discrete brain regions. A common method for discerning the function of various brain regions for behavior or other experimental outcomes is to implement a localized ablation of function. In humans, patient populations with localized brain lesions are often studied for deficits, in hopes of revealing the underlying function of the damaged area. In rodents, one can experimentally induce lesions of specific brain regions. Lesion can be accomplished in several ways. Electrolytic lesions can cause localized damage but will damage a variety of cell types as well as traversing fibers from other brain regions that happen to be near the lesion site. Inducible genetic techniques using cell-type specific promoters may also enable site-specific targeting. These techniques are complex and not always practical depending on the target brain area. Excitotoxic lesion using stereotaxic surgery, by contrast, is one of the most reliable and practical methods of lesioning excitatory neurons without damaging local glial cells or traversing fibers. Here, we present a protocol for stereotaxic infusion of the excitotoxin, N-methyl-D-aspartate (NMDA), into the basolateral amygdala complex. Using anatomical indications, we apply stereotaxic coordinates to determine the location of our target brain region and lower an injection needle in place just above the target. We then infuse our excitotoxin into the brain, resulting in excitotoxic death of nearby neurons. While our experimental subject of choice is a rat, the same methods can be applied to other mammals, with the appropriate adjustments in equipment and coordinates. This method can be used on a variety of brain regions, including the basolateral amygdala1-6, other amygdala nuclei6, 7, hippocampus8, entorhinal cortex9 and prefrontal cortex10. It can also be used to infuse biological compounds such as viral vectors1, 11. The basic stereotaxic technique could also be adapted for implantation of more permanent osmotic pumps, allowing more prolonged exposure to a compound of interest. PMID:22847556

Kirby, Elizabeth D.; Jensen, Kelly; Goosens, Ki A.; Kaufer, Daniela

2012-01-01

101

Laser technique for anatomical-functional study of the medial prefrontal cortex of the brain  

NASA Astrophysics Data System (ADS)

The brain represents one of the most complex systems that we know yet. In its study, non-destructive methods -- in particular, behavioral studies play an important role. By alteration of brain functioning (e.g. by pharmacological means) and observation of consequent behavior changes an important information on brain organization and functioning is obtained. For inducing local alterations, permanent brain lesions are employed. However, for correct results this technique has to be quasi-non-destructive, i.e. not to affect the normal brain function. Hence, the lesions should be very small, accurate and applied precisely over the structure (e.g. the brain nucleus) of interest. These specifications are difficult to meet with the existing techniques for brain lesions -- specifically, neurotoxical, mechanical and electrical means because they result in too extensive damage. In this paper, we present new laser technique for quasi-non- destructive anatomical-functional mapping in vivo of the medial prefrontal cortex (MPFC) of the rat. The technique is based on producing of small-size, well-controlled laser- induced lesions over some areas of the MPFC. The anesthetized animals are subjected to stereotactic surgery and certain points of the MPFC are exposed the confined radiation of the 10 W cw CO2 laser. Subsequent behavioral changes observed in neonatal and adult animals as well as histological data prove effectiveness of this technology for anatomical- functional studies of the brain by areas, and as a treatment method for some pathologies.

Sanchez-Huerta, Laura; Hernandez, Adan; Ayala, Griselda; Marroquin, Javier; Silva, Adriana B.; Khotiaintsev, Konstantin S.; Svirid, Vladimir A.; Flores, Gonzalo; Khotiaintsev, Sergei N.

1999-05-01

102

Gender-specific impact of personal health parameters on individual brain aging in cognitively unimpaired elderly subjects  

PubMed Central

Aging alters brain structure and function. Personal health markers and modifiable lifestyle factors are related to individual brain aging as well as to the risk of developing Alzheimer's disease (AD). This study used a novel magnetic resonance imaging (MRI)-based biomarker to assess the effects of 17 health markers on individual brain aging in cognitively unimpaired elderly subjects. By employing kernel regression methods, the expression of normal brain-aging patterns forms the basis to estimate the brain age of a given new subject. If the estimated age is higher than the chronological age, a positive brain age gap estimation (BrainAGE) score indicates accelerated atrophy and is considered a risk factor for developing AD. Within this cross-sectional, multi-center study 228 cognitively unimpaired elderly subjects (118 males) completed an MRI at 1.5Tesla, physiological and blood parameter assessments. The multivariate regression model combining all measured parameters was capable of explaining 39% of BrainAGE variance in males (p < 0.001) and 32% in females (p < 0.01). Furthermore, markers of the metabolic syndrome as well as markers of liver and kidney functions were profoundly related to BrainAGE scores in males (p < 0.05). In females, markers of liver and kidney functions as well as supply of vitamin B12 were significantly related to BrainAGE (p < 0.05). In conclusion, in cognitively unimpaired elderly subjects several clinical markers of poor health were associated with subtle structural changes in the brain that reflect accelerated aging, whereas protective effects on brain aging were observed for markers of good health. Additionally, the relations between individual brain aging and miscellaneous health markers show gender-specific patterns. The BrainAGE approach may thus serve as a clinically relevant biomarker for the detection of subtly abnormal patterns of brain aging probably preceding cognitive decline and development of AD. PMID:24904408

Franke, Katja; Ristow, Michael; Gaser, Christian

2014-01-01

103

Brain specific delivery of pegylated indinavir submicron lipid emulsions.  

PubMed

The aim of this study was to develop stable parenteral pegylated indinavir submicron lipid emulsions (SLEs) for improving brain specific delivery. The O/W SLEs were prepared by homogenization and ultra sonication process. The sizes of oil globules varied from 241.5 to 296.4nm and zeta potential from -26.6 to -42.4mV. During in vitro drug release studies the cumulative amount of drug released within 12h from SLE-5, DSP2-3 and DPP5-3 was 71.8±0.76, 66.09±1.45 and 68.33±1.29, respectively. The total drug content and entrapment efficiencies were determined. The optimized formulations were stable for the effect of centrifugal stress, thermal stress, dilution stress and storage. In vivo pharmacokinetic and tissue distribution studies were performed in Swiss albino mice, the therapeutic availability (TA) of DSP2-3 was 3.59 times and 2.36 times in comparison to drug solution and SLE-5 respectively, where as DPP5-3 showed TA 2.8 and 1.84 times the drug solution and SLE-5, respectively. The brain to serum ratio of indinavir from DSP2-3 and DPP5-3 varied between 0.4 and 0.7 at all time points indicated the preferential accumulation of drug in brain. In conclusion, pegylated SLEs improved brain specific delivery of indinavir and will be useful in treating chronic HIV infection. PMID:21292000

Kandadi, Prabhakar; Syed, Muzammil Afzal; Goparaboina, Surendar; Veerabrahma, Kishan

2011-03-18

104

Imaging structural and functional brain networks in temporal lobe epilepsy  

PubMed Central

Early imaging studies in temporal lobe epilepsy (TLE) focused on the search for mesial temporal sclerosis, as its surgical removal results in clinically meaningful improvement in about 70% of patients. Nevertheless, a considerable subgroup of patients continues to suffer from post-operative seizures. Although the reasons for surgical failure are not fully understood, electrophysiological and imaging data suggest that anomalies extending beyond the temporal lobe may have negative impact on outcome. This hypothesis has revived the concept of human epilepsy as a disorder of distributed brain networks. Recent methodological advances in non-invasive neuroimaging have led to quantify structural and functional networks in vivo. While structural networks can be inferred from diffusion MRI tractography and inter-regional covariance patterns of structural measures such as cortical thickness, functional connectivity is generally computed based on statistical dependencies of neurophysiological time-series, measured through functional MRI or electroencephalographic techniques. This review considers the application of advanced analytical methods in structural and functional connectivity analyses in TLE. We will specifically highlight findings from graph-theoretical analysis that allow assessing the topological organization of brain networks. These studies have provided compelling evidence that TLE is a system disorder with profound alterations in local and distributed networks. In addition, there is emerging evidence for the utility of network properties as clinical diagnostic markers. Nowadays, a network perspective is considered to be essential to the understanding of the development, progression, and management of epilepsy. PMID:24098281

Bernhardt, Boris C.; Hong, SeokJun; Bernasconi, Andrea; Bernasconi, Neda

2013-01-01

105

Differences in Brain Function and Changes with Intervention in Children with Poor Spelling and Reading Abilities  

Microsoft Academic Search

Previous fMRI studies in English-speaking samples suggested that specific interventions may alter brain function in language-relevant networks in children with reading and spelling difficulties, but this research strongly focused on reading impaired individuals. Only few studies so far investigated characteristics of brain activation associated with poor spelling ability and whether a specific spelling intervention may also be associated with distinct

Daniela Gebauer; Andreas Fink; Reinhard Kargl; Gernot Reishofer; Karl Koschutnig; Christian Purgstaller; Franz Fazekas; Christian Enzinger

2012-01-01

106

Functional photoacoustic tomography of animal brains  

E-print Network

the most rewarding experience in my life. I would like to thank Dr. Lihong Wang for supporting me through his research funding and for providing me this great opportunity to study in his lab. His broad knowledge and acute insight guided me all through...-animal Brains in situ............................................................ 13 3.1 Photoacoustic imaging of mouse brains in situ................................... 13 3.2 Photoacoustic imaging of rat brains in situ...

Wang, Xueding

2005-11-01

107

What Is the Function of Mind and Brain?  

Microsoft Academic Search

Byrnes and Fox (1998) provide a useful and important overview of the ways in which cognitive neuroscientific research can inform educational research and practice, but leave unanswered the question: What is the function of mind and brain? An understanding of the function of mind and brain has implications for research in cognitive neuroscience and in educational psychology, and a number

David C. Geary

1998-01-01

108

Brain serotonin and pituitary-adrenal functions  

NASA Technical Reports Server (NTRS)

It had been concluded by Scapagnini et al. (1971) that brain serotonin (5-HT) was involved in the regulation of the diurnal rhythm of the pituitary-adrenal system but not in the stress response. A study was conducted to investigate these findings further by evaluating the effects of altering brain 5-HT levels on the daily fluctuation of plasma corticosterone and on the response of the pituitary-adrenal system to a stressful or noxious stimulus in the rat. In a number of experiments brain 5-HT synthesis was inhibited with parachlorophenylalanine. In other tests it was tried to raise the level of brain 5-HT with precursors.

Vernikos-Danellis, J.; Berger, P.; Barchas, J. D.

1973-01-01

109

Computed Tomography-Estimated Specific Gravity of Noncontused Brain Areas as a Marker of Severity in Human Traumatic Brain Injury  

Microsoft Academic Search

In this study, we assessed the relationship between brain estimated specific gravity (eSG) and clinical symptoms, therapeutic intensity level, and outcome in human traumatic brain injury (TBI). Brain weight, volume, and eSG of the noncontused hemispheric areas were measured from computed tomography (CT) DICOM images on the initial (5 6 h) CT of 120 patients with severe TBI. Control values

Vincent Degos; Thomas Lescot; Abderrezak Zouaoui; Harold Hermann; Pierre Coriat; Louis Puybasset

2006-01-01

110

Structure-function relationships in human brain development  

E-print Network

The integration of anatomical, functional, and developmental approaches in cognitive neuroscience is essential for generating mechanistic explanations of brain function. In this thesis, I first establish a proof-of-principle ...

Saygin, Zeynep Mevhibe

2012-01-01

111

Nonparametric hierarchical Bayesian model for functional brain parcellation  

E-print Network

We develop a method for unsupervised analysis of functional brain images that learns group-level patterns of functional response. Our algorithm is based on a generative model that comprises two main layers. At the lower ...

Lashkari, Danial

112

A Network Analysis Approach to fMRI Condition-Specific Functional Connectivity  

E-print Network

In this work we focus on examination and comparison of whole-brain functional connectivity patterns measured with fMRI across experimental conditions. Direct examination and comparison of condition-specific matrices is challenging due to the large number of elements in a connectivity matrix. We present a framework that uses network analysis to describe condition-specific functional connectivity. Treating the brain as a complex system in terms of a network, we extract the most relevant connectivity information by partitioning each network into clusters representing functionally connected brain regions. Extracted clusters are used as features for predicting experimental condition in a new data set. The approach is illustrated on fMRI data examining functional connectivity patterns during processing of abstract and concrete concepts. Topological (brain regions) and functional (level of connectivity and information flow) systematic differences in the ROI-based functional networks were identified across participan...

Shinkareva, Svetlana V; Wang, Jing

2010-01-01

113

Brief Communications Efficiency of Functional Brain Networks and Intellectual Performance  

E-print Network

Our brain is a complex network in which information is continuously processed and transported between spatially distributed but functionally linked regions. Recent studies have shown that the functional connections of the brain network are organized in a highly efficient small-world manner, indicating a high level of local neighborhood clustering, together with the existence of more long-distance connectionsthatensureahighlevelofglobalcommunicationefficiencywithintheoverallnetwork.Suchanefficientnetworkarchitecture of our functional brain raises the question of a possible association between how efficiently the regions of our brain are functionally connected and our level of intelligence. Examining the overall organization of the brain network using graph analysis, we show a strong negative association between the normalized characteristic path length ? of the resting-state brain network and intelligence quotient (IQ). This suggests that human intellectual performance is likely to be related to how efficiently our brain integrates information between multiple brain regions. Most pronounced effects between normalized path length and IQ were found in frontal and parietal regions. Our findings indicate a strong positive association between the global efficiency of functional brain networks and intellectual performance.

Martijn P. Van Den Heuvel; Cornelis J. Stam; René S. Kahn; Hilleke E. Hulshoff Pol

114

Efficiency of weak brain connections support general cognitive functioning.  

PubMed

Brain network topology provides valuable information on healthy and pathological brain functioning. Novel approaches for brain network analysis have shown an association between topological properties and cognitive functioning. Under the assumption that "stronger is better", the exploration of brain properties has generally focused on the connectivity patterns of the most strongly correlated regions, whereas the role of weaker brain connections has remained obscure for years. Here, we assessed whether the different strength of connections between brain regions may explain individual differences in intelligence. We analyzed-functional connectivity at rest in ninety-eight healthy individuals of different age, and correlated several connectivity measures with full scale, verbal, and performance Intelligent Quotients (IQs). Our results showed that the variance in IQ levels was mostly explained by the distributed communication efficiency of brain networks built using moderately weak, long-distance connections, with only a smaller contribution of stronger connections. The variability in individual IQs was associated with the global efficiency of a pool of regions in the prefrontal lobes, hippocampus, temporal pole, and postcentral gyrus. These findings challenge the traditional view of a prominent role of strong functional brain connections in brain topology, and highlight the importance of both strong and weak connections in determining the functional architecture responsible for human intelligence variability. PMID:24585433

Santarnecchi, Emiliano; Galli, Giulia; Polizzotto, Nicola Riccardo; Rossi, Alessandro; Rossi, Simone

2014-09-01

115

Portfolio Review: Human Functional Brain Imaging | 1110 | Portfolio Review: Human Functional Brain Imaging 1990 20001993 20031996 20061991 20011994 20041997 20071992 20021995 20051998 20081999 2009 2010  

E-print Network

Portfolio Review: Human Functional Brain Imaging | 1110 | Portfolio Review: Human Functional Brain SINAPSE initiative launched 2010 NIH Human Connectome Project launched 2003 Dynamic causal modelling of human brain/Living Art Enterprises, Science Photo Libra

Rambaut, Andrew

116

The dynamic dielectric at a brain functional site and an em wave approach to functional brain imaging.  

PubMed

Functional brain imaging has tremendous applications. The existing methods for functional brain imaging include functional Magnetic Resonant Imaging (fMRI), scalp electroencephalography (EEG), implanted EEG, magnetoencephalography (MEG) and Positron Emission Tomography (PET), which have been widely and successfully applied to various brain imaging studies. To develop a new method for functional brain imaging, here we show that the dielectric at a brain functional site has a dynamic nature, varying with local neuronal activation as the permittivity of the dielectric varies with the ion concentration of the extracellular fluid surrounding neurons in activation. Therefore, the neuronal activation can be sensed by a radiofrequency (RF) electromagnetic (EM) wave propagating through the site as the phase change of the EM wave varies with the permittivity. Such a dynamic nature of the dielectric at a brain functional site provides the basis for an RF EM wave approach to detecting and imaging neuronal activation at brain functional sites, leading to an RF EM wave approach to functional brain imaging. PMID:25367217

Li, X P; Xia, Q; Qu, D; Wu, T C; Yang, D G; Hao, W D; Jiang, X; Li, X M

2014-01-01

117

The Dynamic Dielectric at a Brain Functional Site and an EM Wave Approach to Functional Brain Imaging  

PubMed Central

Functional brain imaging has tremendous applications. The existing methods for functional brain imaging include functional Magnetic Resonant Imaging (fMRI), scalp electroencephalography (EEG), implanted EEG, magnetoencephalography (MEG) and Positron Emission Tomography (PET), which have been widely and successfully applied to various brain imaging studies. To develop a new method for functional brain imaging, here we show that the dielectric at a brain functional site has a dynamic nature, varying with local neuronal activation as the permittivity of the dielectric varies with the ion concentration of the extracellular fluid surrounding neurons in activation. Therefore, the neuronal activation can be sensed by a radiofrequency (RF) electromagnetic (EM) wave propagating through the site as the phase change of the EM wave varies with the permittivity. Such a dynamic nature of the dielectric at a brain functional site provides the basis for an RF EM wave approach to detecting and imaging neuronal activation at brain functional sites, leading to an RF EM wave approach to functional brain imaging. PMID:25367217

Li, X. P.; Xia, Q.; Qu, D.; Wu, T. C.; Yang, D. G.; Hao, W. D.; Jiang, X.; Li, X. M.

2014-01-01

118

Region-specific tolerance criteria for the living brain.  

PubMed

Computational models of traumatic brain injury (TBI) can predict injury-induced brain deformation. However, predicting the biological consequences (i.e. cell death or dysfunction) of induced brain deformation requires tolerance criteria. Here, we present a tolerance criterion for the cortex which exhibits important differences from that of the hippocampus. Organotypic slice cultures of the rat cortex, which maintain tissue architecture and cell content consistent with that in vivo, were mechanically injured with an in vitro model described previously. Cultures were stretched equibiaxially up to 0.35 Lagrangian strain at strain rates up to 50 s(-1). Cell death was quantified at 1, 2, 3, and 4 days following injury. Statistical analysis (repeated measures ANOVA) showed that all three factors (Strain, Strain Rate, and Time post-injury) significantly affected cell death. An equation describing cell death as a function of the significant parameters was then fit to the data. Compared to the hippocampus, the cortex was less vulnerable to stretch-induced injury and demonstrated a strain threshold below 0.20. Strain rate was also a significant factor for cortical but not hippocampal cell death. Cortical cell death began at an earlier time point than in the hippocampus, with cell death evident at 1 day post-injury versus 3 days in the hippocampus. In conclusion, different regions of the brain respond differently to identical mechanical stimuli, and this difference should be incorporated into finite element models of TBI if they are to more accurately predict in vivo consequences of TBI. PMID:18278594

Elkin, Benjamin S; Morrison, Barclay

2007-10-01

119

Comparison of Swallowing Functions Between Brain Tumor and Stroke Patients  

PubMed Central

Objective To compare the swallowing functions according to the lesion locations between brain tumor and stroke patients. Methods Forty brain tumor patients and the same number of age-, lesion-, and functional status-matching stroke patients were enrolled in this study. Before beginning the swallowing therapy, swallowing function was evaluated in all subjects by videofluoroscopic swallowing study. Brain lesions were classified as either supratentorial or in-fratentorial. We evaluated the following: the American Speech-Language-Hearing Association (ASHA) National Outcome Measurement System (NOMS) swallowing scale, clinical dysphagia scale, functional dysphagia scale (FDS), penetration-aspiration scale (PAS), oral transit time, pharyngeal transit time, the presence of vallecular pouch residue, pyriform sinus residue, laryngopharyngeal incoordination, premature spillage, a decreased swal-lowing reflex, pneumonia, and the feeding method at discharge. Results The incidence of dysphagia was similar in brain tumor and stroke patients. There were no differences in the results of the various swallowing scales and other parameters between the two groups. When compared brain tumor patients with supratentorial lesions, brain tumor patients with infratentorial lesions showed higher propor-tion of dysphagia (p=0.01), residue (p<0.01), FDS (p<0.01), PAS (p<0.01), and lower ASHA NOMS (p=0.02) at initial evaluation. However, there was no significant difference for the swallowing functions between benign and malig-nant brain tumor patients. Conclusion Swallowing function of brain tumor patients was not different from that of stroke patients according to matching age, location of lesion, and functional status. Similar to the stroke patients, brain tumor patients with infratentorial lesions present poor swallowing functions. However, the type of brain tumor as malignancy does not influence swallowing functions. PMID:24231855

Park, Dae Hwan; Lee, Sook Joung; Song, Yoon Bum

2013-01-01

120

Development of large-scale functional brain networks in children.  

PubMed

The ontogeny of large-scale functional organization of the human brain is not well understood. Here we use network analysis of intrinsic functional connectivity to characterize the organization of brain networks in 23 children (ages 7-9 y) and 22 young-adults (ages 19-22 y). Comparison of network properties, including path-length, clustering-coefficient, hierarchy, and regional connectivity, revealed that although children and young-adults' brains have similar "small-world" organization at the global level, they differ significantly in hierarchical organization and interregional connectivity. We found that subcortical areas were more strongly connected with primary sensory, association, and paralimbic areas in children, whereas young-adults showed stronger cortico-cortical connectivity between paralimbic, limbic, and association areas. Further, combined analysis of functional connectivity with wiring distance measures derived from white-matter fiber tracking revealed that the development of large-scale brain networks is characterized by weakening of short-range functional connectivity and strengthening of long-range functional connectivity. Importantly, our findings show that the dynamic process of over-connectivity followed by pruning, which rewires connectivity at the neuronal level, also operates at the systems level, helping to reconfigure and rebalance subcortical and paralimbic connectivity in the developing brain. Our study demonstrates the usefulness of network analysis of brain connectivity to elucidate key principles underlying functional brain maturation, paving the way for novel studies of disrupted brain connectivity in neurodevelopmental disorders such as autism. PMID:19621066

Supekar, Kaustubh; Musen, Mark; Menon, Vinod

2009-07-01

121

State-related functional integration and functional segregation brain networks in schizophrenia  

PubMed Central

Altered topological properties of brain connectivity networks have emerged as important features of schizophrenia. The aim of this study was to investigate how the state-related modulations to graph measures of functional integration and functional segregation brain networks are disrupted in schizophrenia. Firstly, resting state and auditory oddball discrimination (AOD) fMRI data of healthy controls (HCs) and schizophrenia patients (SZs) were decomposed into spatially independent components (ICs) by group independent component analysis (ICA). Then, weighted positive and negative functional integration (inter-component networks) and functional segregation (intra-component networks) brain networks were built in each subject. Subsequently, connectivity strength, clustering coefficient, and global efficiency of all brain networks were statistically compared between groups (HCs and SZs) in each state and between states (rest and AOD) within group. We found that graph measures of negative functional integration brain network and several positive functional segregation brain networks were altered in schizophrenia during AOD task. The metrics of positive functional integration brain network and one positive functional segregation brain network were higher during the resting state than during the AOD task only in HCs. These findings imply that state-related characteristics of both functional integration and functional segregation brain networks are impaired in schizophrenia which provides new insight into the altered brain performance in this brain disorder. PMID:24094882

Yu, Qingbao; Sui, Jing; Kiehl, Kent A.; Pearlson, Godfrey; Calhoun, Vince D.

2013-01-01

122

Delivery of circulating lipoproteins to specific neurons in the Drosophila brain regulates systemic insulin signaling  

PubMed Central

The Insulin signaling pathway couples growth, development and lifespan to nutritional conditions. Here, we demonstrate a function for the Drosophila lipoprotein LTP in conveying information about dietary lipid composition to the brain to regulate Insulin signaling. When yeast lipids are present in the diet, free calcium levels rise in Blood Brain Barrier glial cells. This induces transport of LTP across the Blood Brain Barrier by two LDL receptor-related proteins: LRP1 and Megalin. LTP accumulates on specific neurons that connect to cells that produce Insulin-like peptides, and induces their release into the circulation. This increases systemic Insulin signaling and the rate of larval development on yeast-containing food compared with a plant-based food of similar nutritional content. DOI: http://dx.doi.org/10.7554/eLife.02862.001 PMID:25275323

Brankatschk, Marko; Dunst, Sebastian; Nemetschke, Linda; Eaton, Suzanne

2014-01-01

123

Brain-specific restoration of angiotensin II corrects renal defects seen in angiotensinogen-deficient mice.  

PubMed

Mice deficient for angiotensinogen (AGT), or other components of the renin-angiotensin system, show a high rate of neonatal mortality correlated with severe renal abnormalities including hydronephrosis, hypertrophy of renal arteries, and an impaired ability to concentrate urine. Although transgenic replacement of systemic or adipose, but not renal, AGT in AGT-deficient mice has previously been reported to correct some of these renal abnormalities, the tissue target for this complementation has not been defined. In the current study, we have used a novel transgenic strategy to restore the peptide product of the renin-angiotensin system, angiotensin II, exclusively in the brain of AGT-deficient mice and demonstrate that brain-specific angiotensin II can correct the hydronephrosis and partially correct renal dysfunction seen in AGT-deficient mice. Taken together, these results suggest that the renin-angiotensin system affects renal development and function through systemically accessible targets in the brain. PMID:12399452

Lochard, Nadheige; Silversides, David W; van Kats, Jorge P; Mercure, Chantal; Reudelhuber, Timothy L

2003-01-24

124

Evidence for hubs in human functional brain networks  

PubMed Central

Summary Hubs integrate and distribute information in powerful ways due to the number and positioning of their contacts in a network. Several resting state functional connectivity MRI reports have implicated regions of the default mode system as brain hubs; we demonstrate that previous degree-based approaches to hub identification may have identified portions of large brain systems rather than critical nodes of brain networks. We utilize two methods to identify hub-like brain regions: 1) finding network nodes that participate in multiple sub-networks of the brain, and 2) finding spatial locations where several systems are represented within a small volume. These methods converge on a distributed set of regions that differ from previous reports on hubs. This work identifies regions that support multiple systems, leading to spatially constrained predictions about brain function that may be tested in terms of lesions, evoked responses, and dynamic patterns of activity. PMID:23972601

Power, Jonathan D; Schlaggar, Bradley L; Lessov-Schlaggar, Christina N; Petersen, Steven E

2013-01-01

125

Decoding brain states using functional magnetic resonance imaging  

Microsoft Academic Search

Most leading research in basic and clinical neuroscience has been carried out by functional magnetic resonance imaging (fMRI),\\u000a which detects the blood oxygenation level dependent signals associated with neural activities. Among new fMRI applications,\\u000a brain decoding is an emerging research area, which infers mental states from fMRI signals. Brain decoding using fMRI includes\\u000a classification, identification, and reconstruction of brain states.

Dongha Lee; Changwon Jang; Hae-Jeong Park

2011-01-01

126

Functional brain imaging in the dementias: role in early detection, differential diagnosis, and longitudinal studies  

Microsoft Academic Search

This review considers the role of functional brain imaging techniques in the dementias. The substantial assistance that especially single-photon emission tomography and positron emission tomography can play in the initial diagnosis of dementia and in the differential diagnosis of the specific dementing disorder is discussed. These techniques alone essentially match the sensitivity and specificity of clinical diagnoses in distinguishing Alzheimer's

Michael D. Devous Sr

2002-01-01

127

Chronic Pain and the Emotional Brain: Specific Brain Activity Associated with Spontaneous Fluctuations of Intensity of Chronic Back Pain  

PubMed Central

Living with unrelenting pain (chronic pain) is maladaptive and is thought to be associated with physiological and psychological modifications, yet there is a lack of knowledge regarding brain elements involved in such conditions. Here, we identify brain regions involved in spontaneous pain of chronic back pain (CBP) in two separate groups of patients (n = 13 and n = 11), and contrast brain activity between spontaneous pain and thermal pain (CBP and healthy subjects, n = 11 each). Continuous ratings of fluctuations of spontaneous pain during functional magnetic resonance imaging were separated into two components: high sustained pain and increasing pain. Sustained high pain of CBP resulted in increased activity in the medial prefrontal cortex (mPFC; including rostral anterior cingulate). This mPFC activity was strongly related to intensity of CBP, and the region is known to be involved in negative emotions, response conflict, and detection of unfavorable outcomes, especially in relation to the self. In contrast, the increasing phase of CBP transiently activated brain regions commonly observed for acute pain, best exemplified by the insula, which tightly reflected duration of CBP. When spontaneous pain of CBP was contrasted to thermal stimulation, we observe a double-dissociation between mPFC and insula with the former correlating only to intensity of spontaneous pain and the latter correlating only to pain intensity for thermal stimulation. These findings suggest that subjective spontaneous pain of CBP involves specific spatiotemporal neuronal mechanisms, distinct from those observed for acute experimental pain, implicating a salient role for emotional brain concerning the self. PMID:17122041

Baliki, Marwan N.; Chialvo, Dante R.; Geha, Paul Y.; Levy, Robert M.; Harden, R. Norman; Parrish, Todd B.; Apkarian, A. Vania

2014-01-01

128

The blind brain: How (lack of) vision shapes the morphological and functional architecture of the human brain.  

PubMed

Since the early days, how we represent the world around us has been a matter of philosophical speculation. Over the last few decades, modern neuroscience, and specifically the development of methodologies for the structural and the functional exploration of the brain have made it possible to investigate old questions with an innovative approach. In this brief review, we discuss the main findings from a series of brain anatomical and functional studies conducted in sighted and congenitally blind individuals by our's and others' laboratories. Historically, research on the 'blind brain' has focused mainly on the cross-modal plastic changes that follow sensory deprivation. More recently, a novel line of research has been developed to determine to what extent visual experience is truly required to achieve a representation of the surrounding environment. Overall, the results of these studies indicate that most of the brain fine morphological and functional architecture is programmed to develop and function independently from any visual experience. Distinct cortical areas are able to process information in a supramodal fashion, that is, independently from the sensory modality that carries that information to the brain. These observations strongly support the hypothesis of a modality-independent, i.e. more abstract, cortical organization, and may contribute to explain how congenitally blind individuals may interact efficiently with an external world that they have never seen. PMID:24962172

Ricciardi, Emiliano; Handjaras, Giacomo; Pietrini, Pietro

2014-11-01

129

Brain microRNAs and insights into biological functions and therapeutic potential of brain enriched miRNA-128  

PubMed Central

MicroRNAs, the non-coding single-stranded RNA of 19–25 nucleotides are emerging as robust players of gene regulation. Plethora of evidences support that the ability of microRNAs to regulate several genes of a pathway or even multiple cross talking pathways have significant impact on a complex regulatory network and ultimately the physiological processes and diseases. Brain being a complex organ with several cell types, expresses more distinct miRNAs than any other tissues. This review aims to discuss about the microRNAs in brain development, function and their dysfunction in brain tumors. We also provide a comprehensive summary of targets of brain specific and brain enriched miRNAs that contribute to the diversity and plasticity of the brain. In particular, we uncover recent findings on miRNA-128, a brain-enriched microRNA that is induced during neuronal differentiation and whose aberrant expression has been reported in several cancers. This review describes the wide spectrum of targets of miRNA-128 that have been identified till date with potential roles in apoptosis, angiogenesis, proliferation, cholesterol metabolism, self renewal, invasion and cancer progression and how this knowledge might be exploited for the development of future miRNA-128 based therapies for the treatment of cancer as well as metabolic diseases. PMID:24555688

2014-01-01

130

Magnetic resonance functional imaging of the brain at 4 t  

Microsoft Academic Search

Blood Oxygenation Level Dependent (BOLD) contrast imaging of human brain function using echo-planar imaging at 4 T gives good freedom from motion artifact, high signal-to-noise ratio\\/unit time, and adequate spatial resolution. Studies were made of brain activation associated with perceptual and cognitive tasks of several minutes duration.

P. Jezzard

1994-01-01

131

Independent component analysis for intraoperative functional brain mapping using laser Doppler imaging  

E-print Network

Independent component analysis for intraoperative functional brain mapping using laser Doppler brain mapping Á Blood perfusion Purpose Intraoperative functional brain mapping during neurosurgery is useful prior to surgical removal of lesions close to functionally important regions. Presurgical planning

Floreano, Dario

132

Complex Networks - A Key to Understanding Brain Function  

SciTech Connect

The brain is a complex network of neurons, engaging in spontaneous and evoked activity that is thought to be the main substrate of mental life. How this complex system works together to process information and generate coherent cognitive states, even consciousness, is not yet well understood. In my talk I will review recent studies that have revealed characteristic structural and functional attributes of brain networks, and discuss efforts to build computational models of the brain that are informed by our growing knowledge of brain anatomy and physiology.

Sporns, Olaf (Indiana University) [Indiana University

2008-01-23

133

Complex Networks - A Key to Understanding Brain Function  

ScienceCinema

The brain is a complex network of neurons, engaging in spontaneous and evoked activity that is thought to be the main substrate of mental life.  How this complex system works together to process information and generate coherent cognitive states, even consciousness, is not yet well understood.  In my talk I will review recent studies that have revealed characteristic structural and functional attributes of brain networks, and discuss efforts to build computational models of the brain that are informed by our growing knowledge of brain anatomy and physiology.

Olaf Sporns

2010-01-08

134

Immune responses at brain barriers and implications for brain development and neurological function in later life  

PubMed Central

For a long time the brain has been considered an immune-privileged site due to a muted inflammatory response and the presence of protective brain barriers. It is now recognized that neuroinflammation may play an important role in almost all neurological disorders and that the brain barriers may be contributing through either normal immune signaling or disruption of their basic physiological mechanisms. The distinction between normal function and dysfunction at the barriers is difficult to dissect, partly due to a lack of understanding of normal barrier function and partly because of physiological changes that occur as part of normal development and ageing. Brain barriers consist of a number of interacting structural and physiological elements including tight junctions between adjacent barrier cells and an array of influx and efflux transporters. Despite these protective mechanisms, the capacity for immune-surveillance of the brain is maintained, and there is evidence of inflammatory signaling at the brain barriers that may be an important part of the body's response to damage or infection. This signaling system appears to change both with normal ageing, and during disease. Changes may affect diapedesis of immune cells and active molecular transfer, or cause rearrangement of the tight junctions and an increase in passive permeability across barrier interfaces. Here we review the many elements that contribute to brain barrier functions and how they respond to inflammation, particularly during development and aging. The implications of inflammation–induced barrier dysfunction for brain development and subsequent neurological function are also discussed. PMID:23986663

Stolp, Helen B.; Liddelow, Shane A.; Sa-Pereira, Ines; Dziegielewska, Katarzyna M.; Saunders, Norman R.

2013-01-01

135

Dynamical intrinsic functional architecture of the brain during absence seizures.  

PubMed

Epilepsy is characterized by recurrent and temporary brain dysfunction due to discharges of interconnected groups of neurons. The brain of epilepsy patients has a dynamic bifurcation that switches between epileptic and normal states. The dysfunctional state involves large-scale brain networks. It is very important to understand the network mechanisms of seizure initiation, maintenance, and termination in epilepsy. Absence epilepsy provides a unique model for neuroimaging investigation on dynamic evolutions of brain networks over seizure repertoire. By using a dynamic functional connectivity and graph theoretical analyses to study absence seizures (AS), we aimed to obtain transition of network properties that account for seizure onset and offset. We measured resting-state functional magnetic resonance imaging and simultaneous electroencephalography (EEG) from children with AS. We used simultaneous EEG to define the preictal, ictal and postictal intervals of seizures. We measured dynamic connectivity maps of the thalamus network and the default mode network (DMN), as well as functional connectome topologies, during the three different seizure intervals. The analysis of dynamic changes of anti-correlation between the thalamus and the DMN is consistent with an inhibitory effect of seizures on the default mode of brain function, which gradually fades out after seizure onset. Also, we observed complex transitions of functional network topology, implicating adaptive reconfiguration of functional brain networks. In conclusion, our work revealed novel insights into modifications in large-scale functional connectome during AS, which may contribute to a better understanding the network mechanisms of state bifurcations in epileptogenesis. PMID:23913255

Liao, Wei; Zhang, Zhiqiang; Mantini, Dante; Xu, Qiang; Ji, Gong-Jun; Zhang, Han; Wang, Jue; Wang, Zhengge; Chen, Guanghui; Tian, Lei; Jiao, Qing; Zang, Yu-Feng; Lu, Guangming

2014-11-01

136

Bioengineers Create Functional 3D Brain-Like Tissue  

MedlinePLUS

... neurons formed functional networks throughout the scaffold pores (dark areas). Image courtesy of Tufts University. As a ... consists of segregated regions of grey and white matter. In the brain, grey matter is comprised primarily ...

137

Functional geometry alignment and localization of brain areas  

E-print Network

Matching functional brain regions across individuals is a challenging task, largely due to the variability in their location and extent. It is particularly difficult, but highly relevant, for patients with pathologies such ...

Langs, Georg

138

Brain Responses to Acupuncture Are Probably Dependent on the Brain Functional Status  

PubMed Central

In recent years, neuroimaging studies of acupuncture have explored extensive aspects of brain responses to acupuncture in finding its underlying mechanisms. Most of these studies have been performed on healthy adults. Only a few studies have been performed on patients with diseases. Brain responses to acupuncture in patients with the same disease at different pathological stages have not been explored, although it may be more important and helpful in uncovering its underlying mechanisms. In the present study, we used fMRI to compare brain responses to acupuncture in patients with Bell's palsy at different pathological stages with normal controls and found that the brain response to acupuncture varied at different pathological stages of Bell's palsy. The brain response to acupuncture decreased in the early stages, increased in the later stages, and nearly returned to normal in the recovered group. All of the changes in the brain response to acupuncture could be explained as resulting from the changes in the brain functional status. Therefore, we proposed that the brain response to acupuncture is dependent on the brain functional status, while further investigation is needed to provide more evidence in support of this proposition. PMID:23737817

Sun, Jinbo; Xu, Chunsheng; Zhu, Yuanqiang; Qin, Wei; Tian, Jie

2013-01-01

139

The role of functional magnetic resonance imaging in brain surgery.  

PubMed

New functional neuroimaging techniques are changing our understanding of the human brain, and there is now convincing evidence to move away from the classic and clinical static concepts of functional topography. In a modern neurocognitive view, functions are thought to be represented in dynamic large-scale networks. The authors review the current (limited) role of functional MR imaging in brain surgery and the possibilities of new functional MR imaging techniques for research and neurosurgical practice. A critique of current clinical gold standard techniques (electrocortical stimulation and the Wada test) is given. PMID:20121439

Rutten, Geert-Jan; Ramsey, Nick F

2010-02-01

140

Intersubject variability of and genetic effects on the brain's functional connectivity during infancy.  

PubMed

Infancy is a period featuring a high level of intersubject variability but the brain basis for such variability and the potential genetic/environmental contributions remain largely unexplored. The assessment of the brain's functional connectivity during infancy by the resting state functional magnetic resonance imaging (rsfMRI) technique (Biswal et al., 1995) provides a unique means to probe the brain basis of intersubject variability during infancy. In this study, an unusually large typically developing human infant sample including 58 singletons, 132 dizygotic twins, and 98 monozygotic twins with rsfMRI scans during the first 2 years of life was recruited to delineate the spatial and temporal developmental patterns of both the intersubject variability of and genetic effects on the brain's functional connectivity. Through systematic voxelwise functional connectivity analyses, our results revealed that the intersubject variability at birth features lower variability in primary functional areas but higher values in association areas. Although the relative pattern remains largely consistent, the magnitude of intersubject variability undergoes an interesting U-shaped growth during the first 2 years of life. Overall, the intersubject variability patterns during infancy show both adult-like and infant-specific characteristics (Mueller et al., 2013). On the other hand, age-dependent genetic effects were observed showing significant but bidirectional relationships with intersubject variability. The temporal and spatial patterns of the intersubject variability of and genetic contributions to the brain's functional connectivity documented in this study shed light on the largely uncharted functional development of the brain during infancy. PMID:25143609

Gao, Wei; Elton, Amanda; Zhu, Hongtu; Alcauter, Sarael; Smith, J Keith; Gilmore, John H; Lin, Weili

2014-08-20

141

Gender Effect on Functional Networks in Resting Brain  

Microsoft Academic Search

Previous studies have witnessed that complex brain networks have the properties of high global and local efficiency. In this\\u000a study, we investigated the gender effect on brain functional networks measured using functional magnetic resonance imaging\\u000a (fMRI). Our experimental results showed that there were no significant difference in global and local efficiency between male\\u000a and female. However, the gender-related effects on

Liang Wang; Chaozhe Zhu; Yong He; Qiuhai Zhong; Yufeng Zang

2007-01-01

142

Generating Text from Functional Brain Images  

PubMed Central

Recent work has shown that it is possible to take brain images acquired during viewing of a scene and reconstruct an approximation of the scene from those images. Here we show that it is also possible to generate text about the mental content reflected in brain images. We began with images collected as participants read names of concrete items (e.g., “Apartment’’) while also seeing line drawings of the item named. We built a model of the mental semantic representation of concrete concepts from text data and learned to map aspects of such representation to patterns of activation in the corresponding brain image. In order to validate this mapping, without accessing information about the items viewed for left-out individual brain images, we were able to generate from each one a collection of semantically pertinent words (e.g., “door,” “window” for “Apartment’’). Furthermore, we show that the ability to generate such words allows us to perform a classification task and thus validate our method quantitatively. PMID:21927602

Pereira, Francisco; Detre, Greg; Botvinick, Matthew

2011-01-01

143

Human Brain Language Areas Identified by Functional Magnetic Resonance Imaging  

Microsoft Academic Search

Functional magnetic resonance imaging (FMRI) was used to identify candidate language processing areas in the intact hu- man brain. Language was defined broadly to include both phonological and lexical-semantic functions and to exclude sensory, motor, and general executive functions. The language activation task required phonetic and semantic analysis of aurally presented words and was compared with a control task involving

Jeffrey R. Binder; Julie A. Frost; Thomas A. Hammeke; Robert W. Cox; Stephen M. Rao; Thomas Prieto

1997-01-01

144

The substrate specificity of brain microsomal phospholipase D.  

PubMed Central

Neurotransmitters activate a phospholipase D that is though to specifically hydrolyse phosphatidylcholine. This enzyme has a unique property known as transphosphatidylation: in the presence of an appropriate nucleophilic receptor such as an alcohol, phospholipase D will catalyse the production of phosphatidyl-alcohol. We have studied phospholipase D using an in vitro assay that uses [3H]butanol of high specific radioactivity (15 Ci/mmol) as an acceptor. In the presence of [3H]butanol and phosphatidylcholine, a microsomal membrane fraction from rat brain catalysed the production of phosphatidyl[3H]butanol. Phospholipase D activity was dependent upon the presence of a detergent; the optimal sodium oleate concentration was between 4 and 6 mM. The RF of the phosphatidyl[3H]butanol on t.l.c. was identical to the RF of the phosphatidylbutanol formed when [3H]phosphatidylcholine was incubated with 100 mM butanol. These data confirm the identity of phosphatidyl[3H]butanol. One important advantage of this assay is that the substrate does not need to be labelled. We have used this advantage to examine the substrate specificity of phospholipase D. Microsomal phospholipase D appears to hydrolyse phosphatidylcholine most efficiently. There is a relatively small but significant activity against phosphatidylethanolamine and phosphatidylserine, and there is no significant activity against phosphatidylinositol. As the head-group becomes more like choline, the phospholipid becomes a better substrate for phospholipase D. The addition of one methyl group leads to a large increase in activity. Fatty acid composition does not play a role in determining the substrate specificity. This assay should be useful in furthering our understanding of this important enzyme. Images Figure 1 PMID:8240294

Horwitz, J; Davis, L L

1993-01-01

145

Quetiapine modulates functional connectivity in brain aggression networks.  

PubMed

Aggressive behavior is associated with dysfunctions in an affective regulation network encompassing amygdala and prefrontal areas such as orbitofrontal (OFC), anterior cingulate (ACC), and dorsolateral prefrontal cortex (DLPFC). In particular, prefrontal regions have been postulated to control amygdala activity by inhibitory projections, and this process may be disrupted in aggressive individuals. The atypical antipsychotic quetiapine successfully attenuates aggressive behavior in various disorders; the underlying neural processes, however, are unknown. A strengthened functional coupling in the prefrontal-amygdala system may account for these anti-aggressive effects. An inhibition of this network has been reported for virtual aggression in violent video games as well. However, there have been so far no in-vivo observations of pharmacological influences on corticolimbic projections during human aggressive behavior. In a double-blind, placebo-controlled study, quetiapine and placebo were administered for three successive days prior to an fMRI experiment. In this experiment, functional brain connectivity was assessed during virtual aggressive behavior in a violent video game and an aggression-free control task in a non-violent modification. Quetiapine increased the functional connectivity of ACC and DLPFC with the amygdala during virtual aggression, whereas OFC-amygdala coupling was attenuated. These effects were observed neither for placebo nor for the non-violent control. These results demonstrate for the first time a pharmacological modification of aggression-related human brain networks in a naturalistic setting. The violence-specific modulation of prefrontal-amygdala networks appears to control aggressive behavior and provides a neurobiological model for the anti-aggressive effects of quetiapine. PMID:23501053

Klasen, Martin; Zvyagintsev, Mikhail; Schwenzer, Michael; Mathiak, Krystyna A; Sarkheil, Pegah; Weber, René; Mathiak, Klaus

2013-07-15

146

Cerebral energy metabolism and the brain's functional network architecture: an integrative review  

PubMed Central

Recent functional magnetic resonance imaging (fMRI) studies have emphasized the contributions of synchronized activity in distributed brain networks to cognitive processes in both health and disease. The brain's ‘functional connectivity' is typically estimated from correlations in the activity time series of anatomically remote areas, and postulated to reflect information flow between neuronal populations. Although the topological properties of functional brain networks have been studied extensively, considerably less is known regarding the neurophysiological and biochemical factors underlying the temporal coordination of large neuronal ensembles. In this review, we highlight the critical contributions of high-frequency electrical oscillations in the ?-band (30 to 100?Hz) to the emergence of functional brain networks. After describing the neurobiological substrates of ?-band dynamics, we specifically discuss the elevated energy requirements of high-frequency neural oscillations, which represent a mechanistic link between the functional connectivity of brain regions and their respective metabolic demands. Experimental evidence is presented for the high oxygen and glucose consumption, and strong mitochondrial performance required to support rhythmic cortical activity in the ?-band. Finally, the implications of mitochondrial impairments and deficits in glucose metabolism for cognition and behavior are discussed in the context of neuropsychiatric and neurodegenerative syndromes characterized by large-scale changes in the organization of functional brain networks. PMID:23756687

Lord, Louis-David; Expert, Paul; Huckins, Jeremy F; Turkheimer, Federico E

2013-01-01

147

Relationship Between Neurocognitive Function and Quality of Life After Whole-Brain Radiotherapy in Patients With Brain Metastasis  

SciTech Connect

Purpose: To examine the relationship between neurocognitive function (NCF) and quality of life (QOL) in patients with brain metastases after whole-brain radiotherapy. Patients and Methods: A total of 208 patients from the whole-brain radiotherapy arm of a Phase III trial (PCI-P120-9801), who underwent regular NCF and QOL (ADL [activities of daily living] and FACT-Br [Functional Assessment of Cancer Therapy-Brain-specific]) testing, were analyzed. Spearman's rank correlation was calculated between NCF and QOL, using each patient's own data, at each time point. To test the hypothesis that NCF declines before QOL changes, the predictive effect of NCF from previous visits on QOL was studied with a linear mixed-effects model. Neurocognitive function or QOL deterioration was defined relative to each patient's own baseline. Lead or lag time, defined as NCF deterioration before or after the date of QOL decline, respectively, was computed. Results: At baseline, all NCF tests showed statistically significant correlations with ADL, which became stronger at 4 months. A similar observation was made with FACT-Br. Neurocognitive function scores from previous visits predicted ADL (p < 0.05 for seven of eight tests) or FACT-Br. Scores on all eight NCF tests deteriorated before ADL decline (net lead time 9-153 days); and scores on six of eight NCF tests deteriorated before FACT-Br (net lead time 9-82 days). Conclusions: Neurocognitive function and QOL are correlated. Neurocognitive function scores from previous visits are predictive of QOL. Neurocognitive function deterioration precedes QOL decline. The sequential association between NCF and QOL decline suggests that delaying NCF deterioration is a worthwhile treatment goal in brain metastases patients.

Li Jing; Bentzen, Soren M. [Department of Human Oncology, University of Wisconsin Comprehensive Cancer Center, Madison, WI (United States); Li Jialiang [Department of Statistics and Applied Probability, National University of Singapore (Singapore); Renschler, Markus [Oncology Clinical Development, Pharmacyclics, Sunnyvale, CA (United States); Mehta, Minesh P. [Department of Human Oncology, University of Wisconsin Comprehensive Cancer Center, Madison, WI (United States)], E-mail: mehta@humonc.wisc.edu

2008-05-01

148

Evolving Knowledge of Sex Differences in Brain Structure, Function and Chemistry  

PubMed Central

Background Clinical and epidemiologic evidence demonstrates sex differences in the prevalence and course of various psychiatric disorders. Understanding sex-specific brain differences in healthy individuals is a critical first step towards understanding sex-specific expression of psychiatric disorders. Here, we evaluate evidence on sex differences in brain structure, chemistry and function using imaging methodologies, including functional magnetic resonance imaging (fMRI), positron emission tomography (PET), single photon emission computed tomography (SPECT) and structural magnetic resonance imaging (MRI) in mentally healthy individuals. Methods MEDLINE searches of English-language literature (1980-November 2006) using the terms sex, gender, PET, SPECT, MRI, fMRI, morphometry, neurochemistry and neurotransmission were performed to extract relevant sources. Results The literature suggests that while there are many similarities in brain structure, function and neurotransmission in healthy men and women, there are important differences that distinguish the male from the female brain. Overall brain volume is greater in men than women, yet, when controlling for total volume, women have a higher percentage of gray matter and men a higher percentage of white matter. Regional volume differences are less consistent. Global cerebral blood flow is higher in women than in men. Sex-specific differences in dopaminergic, serotonergic and GABAergic markers indicate that male and female brains are neurochemically distinct. Conclusions Insight into the etiology of sex differences in the normal living human brain provides an important foundation to delineate the pathophysiological mechanisms underlying sex differences in neuropsychiatric disorders and to guide the development of sex-specific treatments for these devastating brain disorders. PMID:17544382

Cosgrove, Kelly P.; Mazure, Carolyn M.; Staley, Julie K.

2009-01-01

149

Changes in functional brain organization and behavioral correlations after rehabilitative therapy using a brain-computer interface  

PubMed Central

This study aims to examine the changes in task-related brain activity induced by rehabilitative therapy using brain-computer interface (BCI) technologies and whether these changes are relevant to functional gains achieved through the use of these therapies. Stroke patients with persistent upper-extremity motor deficits received interventional rehabilitation therapy using a closed-loop neurofeedback BCI device (n = 8) or no therapy (n = 6). Behavioral assessments using the Stroke Impact Scale, the Action Research Arm Test (ARAT), and the Nine-Hole Peg Test (9-HPT) as well as task-based fMRI scans were conducted before, during, after, and 1 month after therapy administration or at analogous intervals in the absence of therapy. Laterality Index (LI) values during finger tapping of each hand were calculated for each time point and assessed for correlation with behavioral outcomes. Brain activity during finger tapping of each hand shifted over the course of BCI therapy, but not in the absence of therapy, to greater involvement of the non-lesioned hemisphere (and lesser involvement of the stroke-lesioned hemisphere) as measured by LI. Moreover, changes from baseline LI values during finger tapping of the impaired hand were correlated with gains in both objective and subjective behavioral measures. These findings suggest that the administration of interventional BCI therapy can induce differential changes in brain activity patterns between the lesioned and non-lesioned hemispheres and that these brain changes are associated with changes in specific motor functions. PMID:25076886

Young, Brittany M.; Nigogosyan, Zack; Walton, Leo M.; Song, Jie; Nair, Veena A.; Grogan, Scott W.; Tyler, Mitchell E.; Edwards, Dorothy F.; Caldera, Kristin; Sattin, Justin A.; Williams, Justin C.; Prabhakaran, Vivek

2014-01-01

150

Brain covariance selection: better individual functional connectivity models using population prior  

E-print Network

Brain covariance selection: better individual functional connectivity models using population prior bertrand.thirion@inria.fr Abstract Spontaneous brain activity, as observed in functional neuroimaging, has been shown to display reproducible structure that expresses brain architecture and car- ries markers

Paris-Sud XI, Université de

151

Repetitive Transcranial Magnetic Stimulation Activates Specific Regions in Rat Brain  

Microsoft Academic Search

Repetitive transcranial magnetic stimulation (rTMS) is a noninvasive technique to induce electric currents in the brain. Although rTMS is being evaluated as a possible alternative to electroconvulsive therapy for the treatment of refractory depression, little is known about the pattern of activation induced in the brain by rTMS. We have compared immediate early gene expression in rat brain after rTMS

Ru-Rong Ji; Carlos D. Aizenman; Charles M. Epstein; Dike Qiu; Justin C. Huang; Fabio Rupp

1998-01-01

152

Functional streams and cortical integration in the human brain.  

PubMed

The processing of brain information relies on the organization of neuronal networks and circuits that in the end must provide the substrate for human cognition. However, the presence of highly complex and multirelay neuronal interactions has limited our ability to disentangle the assemblies of brain systems. The present review article focuses on the latest developments to understand the architecture of functional streams of the human brain at the large-scale level. Particularly, this article presents a comprehensive framework and recent findings about how the highly modular sensory cortex, such as the visual, somatosensory, auditory, as well as motor cortex areas, connects to more parallel-organized cortical hubs in the brain's functional connectome. PMID:24737695

Sepulcre, Jorge

2014-10-01

153

Micro-compartment specific T2? relaxation in the brain  

PubMed Central

MRI at high field can be sensitized to the magnetic properties of tissues, which introduces a signal dependence on the orientation of white matter (WM) fiber bundles relative to the magnetic field. In addition, study of the NMR relaxation properties of this signal has indicated contributions from compartmentalized water environments inside and outside the myelin sheath that may be separable. Here we further investigated the effects of water compartmentalization on the MRI signal with the goal of extracting compartment-specific information. By comparing MRI measurements of human and marmoset brain at 7 T with magnetic field modeling, we show that: (1) water between the myelin lipid bilayers, in the axonal, and in the interstitial space each experience characteristic magnetic field effects that depend on fiber orientation (2) these field effects result in characteristic relaxation properties and frequency shifts for these compartments; and (3) compartmental contributions may be separated by multi-component fitting of the MRI signal relaxation (i.e. decay) curve. We further show the potential application of these findings to the direct mapping of myelin content and assessment of WM fiber integrity with high field MRI. PMID:23528924

Sati, Pascal; van Gelderen, Peter; Silva, Afonso C.; Reich, Daniel S.; Merkle, Hellmut; de Zwart, Jacco A.; Duyn, Jeff H.

2013-01-01

154

Micro-compartment specific T2* relaxation in the brain.  

PubMed

MRI at high field can be sensitized to the magnetic properties of tissues, which introduces a signal dependence on the orientation of white matter (WM) fiber bundles relative to the magnetic field. In addition, study of the NMR relaxation properties of this signal has indicated contributions from compartmentalized water environments inside and outside the myelin sheath that may be separable. Here we further investigated the effects of water compartmentalization on the MRI signal with the goal of extracting compartment-specific information. By comparing MRI measurements of human and marmoset brain at 7T with magnetic field modeling, we show that: (1) water between the myelin lipid bilayers, in the axonal, and in the interstitial space each experience characteristic magnetic field effects that depend on fiber orientation (2) these field effects result in characteristic relaxation properties and frequency shifts for these compartments; and (3) compartmental contributions may be separated by multi-component fitting of the MRI signal relaxation (i.e. decay) curve. We further show the potential application of these findings to the direct mapping of myelin content and assessment of WM fiber integrity with high field MRI. PMID:23528924

Sati, Pascal; van Gelderen, Peter; Silva, Afonso C; Reich, Daniel S; Merkle, Hellmut; de Zwart, Jacco A; Duyn, Jeff H

2013-08-15

155

Functional Brain Networks Develop from a “Local to Distributed” Organization  

Microsoft Academic Search

The mature human brain is organized into a collection of specialized functional networks that flexibly interact to support various cognitive functions. Studies of development often attempt to identify the organizing principles that guide the maturation of these functional networks. In this report, we combine resting state functional connectivity MRI (rs-fcMRI), graph analysis, community detection, and spring-embedding visualization techniques to analyze

Damien A. Fair; Alexander L. Cohen; Jonathan D. Power; Nico U. F. Dosenbach; Jessica A. Church; Francis M. Miezin; Bradley L. Schlaggar; Steven E. Petersen

2009-01-01

156

The adolescent brain: Insights from functional neuroimaging research  

PubMed Central

With the development of functional neuroimaging tools, the past two decades have witnessed an explosion of work examining functional brain maps, mostly in the adult brain. Against this backdrop of work in adults, developmental research begins to gather a substantial body of knowledge about brain maturation. The purpose of this review is to present some of these findings from the perspective of functional neuroimaging. First, a brief survey of available neuroimaging techniques (i.e., fMRI, MRS, MEG, PET, SPECT, and infrared techniques) is provided. Next, the key cognitive, emotional, and social changes taking place during adolescence are outlined. The third section gives examples of how these behavioral changes can be understood from a neuroscience perspective. The conclusion places this functional neuroimaging research in relation to clinical and molecular work, and shows how answers will ultimately come from the combined efforts of these disciplines. PMID:18383544

Ernst, M.; Mueller, S.C.

2009-01-01

157

Evolution of cognitive function via redeployment of brain areas.  

PubMed

The creative reuse of existing neural components may have played a significant role in the evolutionary development of cognition. There are obvious evolutionary advantages to such redeployment, and the data presented here confirm three important empirical predictions of this account of the development of cognition: 1) A typical brain area will be used by many cognitive functions in diverse task categories, (2) evolutionarily older brain areas will be deployed in more cognitive functions, and (3) more recent cognitive functions will use more, and more widely scattered, brain areas. These findings have implications not just for our understanding of the evolutionary origins of cognitive function but also for the practice of both clinical and experimental neuroscience. PMID:17229971

Anderson, Michael L

2007-02-01

158

Early Bifrontal Brain Injury: Disturbances in Cognitive Function Development  

PubMed Central

We describe six psychomotor, language, and neuropsychological sequential developmental evaluations in a boy who sustained a severe bifrontal traumatic brain injury (TBI) at 19 months of age. Visuospatial, drawing, and writing skills failed to develop normally. Gradually increasing difficulties were noted in language leading to reading and spontaneous speech difficulties. The last two evaluations showed executive deficits in inhibition, flexibility, and working memory. Those executive abnormalities seemed to be involved in the other impairments. In conclusion, early frontal brain injury disorganizes the development of cognitive functions, and interactions exist between executive function and other cognitive functions during development. PMID:21188227

Bonnier, Christine; Costet, Aurelie; Hmaimess, Ghassan; Catale, Corinne; Maillart, Christelle; Marique, Patricia

2010-01-01

159

Magnetic resonance and the human brain: anatomy, function and metabolism  

Microsoft Academic Search

.  The introduction and development, over the last three decades, of magnetic resonance (MR) imaging and MR spectroscopy technology\\u000a for in vivo studies of the human brain represents a truly remarkable achievement, with enormous scientific and clinical ramifications.\\u000a These effectively non-invasive techniques allow for studies of the anatomy, the function and the metabolism of the living\\u000a human brain. They have allowed

I.-F. Talos; A. Z. Mian; K. H. Zou; L. Hsu; D. Goldberg-Zimring; S. Haker; J. G. Bhagwat; R. V. Mulkern

2006-01-01

160

Space shuttle configuration accounting functional design specification  

NASA Technical Reports Server (NTRS)

An analysis is presented of the requirements for an on-line automated system which must be capable of tracking the status of requirements and engineering changes and of providing accurate and timely records. The functional design specification provides the definition, description, and character length of the required data elements and the interrelationship of data elements to adequately track, display, and report the status of active configuration changes. As changes to the space shuttle program levels II and III configuration are proposed, evaluated, and dispositioned, it is the function of the configuration management office to maintain records regarding changes to the baseline and to track and report the status of those changes. The configuration accounting system will consist of a combination of computers, computer terminals, software, and procedures, all of which are designed to store, retrieve, display, and process information required to track proposed and proved engineering changes to maintain baseline documentation of the space shuttle program levels II and III.

1974-01-01

161

How does the metric choice affect brain functional connectivity networks?  

Microsoft Academic Search

Brain functional connectivity has gained increasing interest over the last few years. The application of Graph Theory on functional connectivity networks (FCNs) has shed light into different topics related to physiology as well as pathology. To this end, different connectivity metrics may be used; however, some concerns are often raised related with inconsistency of results and their associated neurophysiological interpretations

C. Lithari; M. A. Klados; C. Papadelis; C. Pappas; M. Albani; P. D. Bamidis

162

Fractal analysis of resting state functional connectivity of the brain  

E-print Network

Fractal analysis of resting state functional connectivity of the brain Wonsang You1 , Sophie Achard neuroimaging data tend to exhibit fractal behavior where their power spectrums follow power-law scaling. Resting state functional connectivity is signicantly inuenced by fractal behav- ior which may not directly

163

Democratic reinforcement: A principle for brain function  

SciTech Connect

We introduce a simple ``toy`` brain model. The model consists of a set of randomly connected, or layered integrate-and-fire neurons. Inputs to and outputs from the environment are connected randomly to subsets of neurons. The connections between firing neurons are strengthened or weakened according to whether the action was successful or not. Unlike previous reinforcement learning algorithms, the feedback from the environment is democratic: it affects all neurons in the same way, irrespective of their position in the network and independent of the output signal. Thus no unrealistic back propagation or other external computation is needed. This is accomplished by a global threshold regulation which allows the system to self-organize into a highly susceptible, possibly ``critical`` state with low activity and sparse connections between firing neurons. The low activity permits memory in quiescent areas to be conserved since only firing neurons are modified when new information is being taught.

Stassinopoulos, D.; Bak, P. [Brookhaven National Laboratory, Upton, New York 11973 (United States)] [Brookhaven National Laboratory, Upton, New York 11973 (United States)

1995-05-01

164

Effect of tumor resection on the characteristics of functional brain networks J. M. Hernndez,1  

E-print Network

Effect of tumor resection on the characteristics of functional brain networks H. Wang,1 L. Douw,2 J. The functional brain networks of a group of patients with brain tumors are measured before and after tumor with brain tumors before and after surgery, the aim of which was to remove the tumor. In brain tumor patients

Van Mieghem, Piet

165

Evaluation of brain hemodynamics with functional near infrared spectroscopy during head-down tilt on young and healthy subjects  

Microsoft Academic Search

Human brain undergoes a number of physiological changes. Especially these changes contributes to optical properties of brain and can be observed with optical imaging methods in visible and near infrared light range. The aim of this study is, by using functional near infrared spectroscopy (fNIRS), with a specific protocol, observing oxygenation and blood volume with respect to time on young

M. Alptekin; V. A. Akin

2010-01-01

166

Stereotactic PET atlas of the human brain: Aid for visual interpretation of functional brain images  

SciTech Connect

In the routine analysis of functional brain images obtained by PET, subjective visual interpretation is often used for anatomic localization. To enhance the accuracy and consistency of the anatomic interpretation, a PET stereotactic atlas and localization approach was designed for functional brain images. The PET atlas was constructed from a high-resolution [{sup 18}F]fluorodeoxyglucose (FDG) image set of a normal volunteer (a 41-yr-ld woman). The image set was reoriented stereotactically, according to the intercommissural (anterior and posterior commissures) line and transformed to the standard stereotactic atlas coordinates. Cerebral structures were annotated on the transaxial planes using a proportional grid system and surface-rendered images. The stereotactic localization technique was applied to image sets from patients with Alzheimer`s disease, and areas of functional alteration were localized visually by referring to the PET atlas. Major brain structures were identified on both transaxial planes and surface-rendered images. In the stereotactic system, anatomic correspondence between the PET atlas and stereotactically reoriented individual image sets of patients with Alzheimer`s disease facilitated both indirect and direct localization of the cerebral structures. Because rapid stereotactic alignment methods for PET images are now available for routine use, the PET atlas will serve as an aid for visual interpretation of functional brain images in the stereotactic system. Widespread application of stereotactic localization may be used in functional brain images, not only in the research setting, but also in routine clinical situations. 41 refs., 3 figs.

Minoshima, S.; Koeppe, R.A.; Frey, A.; Ishihara, M.; Kuhl, D.E. [Univ. of Michigan, Ann Arbor, MI (United States)

1994-06-01

167

Analyzing complex functional brain networks: Fusing statistics and network science to understand the brain  

PubMed Central

Complex functional brain network analyses have exploded over the last decade, gaining traction due to their profound clinical implications. The application of network science (an interdisciplinary offshoot of graph theory) has facilitated these analyses and enabled examining the brain as an integrated system that produces complex behaviors. While the field of statistics has been integral in advancing activation analyses and some connectivity analyses in functional neuroimaging research, it has yet to play a commensurate role in complex network analyses. Fusing novel statistical methods with network-based functional neuroimage analysis will engender powerful analytical tools that will aid in our understanding of normal brain function as well as alterations due to various brain disorders. Here we survey widely used statistical and network science tools for analyzing fMRI network data and discuss the challenges faced in filling some of the remaining methodological gaps. When applied and interpreted correctly, the fusion of network scientific and statistical methods has a chance to revolutionize the understanding of brain function. PMID:25309643

Simpson, Sean L.; Bowman, F. DuBois; Laurienti, Paul J.

2014-01-01

168

Altered host behaviour and brain serotonergic activity caused by acanthocephalans: evidence for specificity  

PubMed Central

Manipulative parasites can alter the phenotype of intermediate hosts in various ways. However, it is unclear whether such changes are just by-products of infection or adaptive and enhance transmission to the final host. Here, we show that the alteration of serotonergic activity is functionally linked to the alteration of specific behaviour in the amphipod Gammarus pulex infected with acanthocephalan parasites. Pomphorhynchus laevis and, to a lesser extent, Pomphorhynchus tereticollis altered phototactism, but not geotactism, in G. pulex, whereas the reverse was true for Polymorphus minutus. Serotonin (5-hydroxytryptamine, 5-HT) injected to uninfected G. pulex mimicked the altered phototactism, but had no effect on geotactism. Photophilic G. pulex infected with P. laevis or P. tereticollis showed a 40% increase in brain 5-HT immunoreactivity compared to photophobic, uninfected individuals. In contrast, brain 5-HT immunoreactivity did not differ between P. minutus-infected and uninfected G. pulex. Finally, brain 5-HT immunoreactivity differed significantly among P. tereticollis-infected individuals in accordance with their degree of manipulation. Our results demonstrate that altered 5-HT activity is not the mere consequence of infection by acanthocephalans but is specifically linked to the disruption of host photophobic behaviour, whereas the alteration of other behaviours such as geotactism may rely on distinct physiological routes. PMID:17015346

Tain, Luke; Perrot-Minnot, Marie-Jeanne; Cezilly, Frank

2006-01-01

169

Control of a specific motor program by a small brain area in zebrafish  

PubMed Central

Complex motor behaviors are thought to be coordinated by networks of brain nuclei that may control different elementary motor programs. Transparent zebrafish larvae offer the opportunity to analyze the functional organization of motor control networks by optical manipulations of neuronal activity during behavior. We examined motor behavior in transgenic larvae expressing channelrhodopsin-2 throughout many neurons in the brain. Wide-field optical stimulation triggered backward and rotating movements caused by the repeated execution of J-turns, a specific motor program that normally occurs during prey capture. Although optically-evoked activity was widespread, behavioral responses were highly coordinated and lateralized. 3-D mapping of behavioral responses to local optical stimuli revealed that J-turns can be triggered specifically in the anterior-ventral optic tectum (avOT) and/or the adjacent pretectum. These results suggest that the execution of J-turns is controlled by a small group of neurons in the midbrain that may act as a command center. The identification of a brain area controlling a defined motor program involved in prey capture is a step toward a comprehensive analysis of neuronal circuits mediating sensorimotor behaviors of zebrafish. PMID:23641200

Fajardo, Otto; Zhu, Peixin; Friedrich, Rainer W.

2013-01-01

170

Cellular mechanisms of brain energy metabolism and their relevance to functional brain imaging.  

PubMed Central

Despite striking advances in functional brain imaging, the cellular and molecular mechanisms that underlie the signals detected by these techniques are still largely unknown. The basic physiological principle of functional imaging is represented by the tight coupling existing between neuronal activity and the associated local increase in both blood flow and energy metabolism. Positron emission tomography (PET) signals detect blood flow, oxygen consumption and glucose use associated with neuronal activity; the degree of blood oxygenation is currently thought to contribute to the signal detected with functional magnetic resonance imaging, while magnetic resonance spectroscopy (MRS) identifies the spatio-temporal pattern of the activity-dependent appearance of certain metabolic intermediates such as glucose or lactate. Recent studies, including those of neurotransmitter-regulated metabolic fluxes in purified preparations and analyses of the cellular localization of enzymes and transporters involved in energy metabolism, as well as in vivo microdialysis and MRS approaches have identified the neurotransmitter glutamate and astrocytes, a specific type of glial cell, as pivotal elements in the coupling of synaptic activity with energy metabolism. Astrocytes are ideally positioned to sense increases in synaptic activity and to couple them with energy metabolism. Indeed they possess specialized processes that cover the surface of intraparenchymal capillaries, suggesting that astrocytes may be a likely site of prevalent glucose uptake. Other astrocyte processes are wrapped around synaptic contacts which possess receptors and reuptake sites for neurotransmitters. Glutamate stimulates glucose uptake into astrocytes. This effect is mediated by specific glutamate transporters present on these cells. The activity of these transporters, which is tightly coupled to the synaptic release of glutamate and operates the clearance of glutamate from the extracellular space, is driven by the electrochemical gradient of Na+. This Na(+)-dependent uptake of glutamate into astrocytes triggers a cascade of molecular events involving the Na+/K(+)-ATPase leading to the glycolytic processing of glucose and the release of lactate by astrocytes. The stoichiometry of this process is such that for one glutamate molecule taken up with three Na+ ions, one glucose molecule enters an astrocyte, two ATP molecules are produced through aerobic glycolysis and two lactate molecules are released. Within the astrocyte, one ATP molecule fuels one 'turn of the pump' while the other provides the energy needed to convert glutamate to glutamine by glutamine synthase. Evidence has been accumulated from structural as well as functional studies indicating that, under aerobic conditions, lactate may be the preferred energy substrate of activated neurons. Indeed, in the presence of oxygen, lactate is converted to pyruvate, which can be processed through the tricarboxylic acid cycle and the associated oxidative phosphorylation, to yield 17 ATP molecules per lactate molecule. These data suggest that during activation the brain may transiently resort to aerobic glycolysis occurring in astrocytes, followed by the oxidation of lactate by neurons. The proposed model provides a direct mechanism to couple synaptic activity with glucose use and is consistent with the notion that the signals detected during physiological activation with 18F-deoxyglucose (DG)-PET may reflect predominantly uptake of the tracer into astrocytes. This conclusion does not question the validity of the 2-DG-based techniques, rather it provides a cellular and molecular basis for these functional brain imaging techniques. PMID:10466143

Magistretti, P J; Pellerin, L

1999-01-01

171

Assortative mixing in functional brain networks during epileptic seizures  

NASA Astrophysics Data System (ADS)

We investigate assortativity of functional brain networks before, during, and after one-hundred epileptic seizures with different anatomical onset locations. We construct binary functional networks from multi-channel electroencephalographic data recorded from 60 epilepsy patients; and from time-resolved estimates of the assortativity coefficient, we conclude that positive degree-degree correlations are inherent to seizure dynamics. While seizures evolve, an increasing assortativity indicates a segregation of the underlying functional network into groups of brain regions that are only sparsely interconnected, if at all. Interestingly, assortativity decreases already prior to seizure end. Together with previous observations of characteristic temporal evolutions of global statistical properties and synchronizability of epileptic brain networks, our findings may help to gain deeper insights into the complicated dynamics underlying generation, propagation, and termination of seizures.

Bialonski, Stephan; Lehnertz, Klaus

2013-09-01

172

Assortative mixing in functional brain networks during epileptic seizures  

E-print Network

We investigate assortativity of functional brain networks before, during, and after one-hundred epileptic seizures with different anatomical onset locations. We construct binary functional networks from multi-channel electroencephalographic data recorded from 60 epilepsy patients, and from time-resolved estimates of the assortativity coefficient we conclude that positive degree-degree correlations are inherent to seizure dynamics. While seizures evolve, an increasing assortativity indicates a segregation of the underlying functional network into groups of brain regions that are only sparsely interconnected, if at all. Interestingly, assortativity decreases already prior to seizure end. Together with previous observations of characteristic temporal evolutions of global statistical properties and synchronizability of epileptic brain networks, our findings may help to gain deeper insights into the complicated dynamics underlying generation, propagation, and termination of seizures.

Bialonski, Stephan

2013-01-01

173

Neuron-glia networks: integral gear of brain function  

PubMed Central

Astrocytes, the most abundant glial cell in the brain, play critical roles in metabolic and homeostatic functions of the Nervous System; however, their participation in coding information and cognitive processes has been largely ignored. The strategic position of astrocyte processes facing synapses and the astrocyte ability to uptake neurotransmitters and release neuroactive substances, so-called “gliotransmitters”, provide the scenario for prolific neuron-astrocyte signaling. From studies at single-cell level to animal behavior, recent advances in technology and genetics have revealed the impact of astrocyte activity in brain function from cellular and synaptic physiology, neuronal circuits to behavior. The present review critically discusses the consequences of astrocyte signaling on synapses and networks, as well as its impact on neuronal information processing, showing that some crucial brain functions arise from the coordinated activity of neuron-glia networks.

Perea, Gertrudis; Sur, Mriganka; Araque, Alfonso

2014-01-01

174

Toward discovery science of human brain function  

E-print Network

Although it is being successfully implemented for exploration of the genome, discovery science has eluded the functional neuroimaging community. The core challenge remains the development of common paradigms for interrogating ...

Gabrieli, Susan

175

Reduction of brain kynurenic acid improves cognitive function.  

PubMed

The elevation of kynurenic acid (KYNA) observed in schizophrenic patients may contribute to core symptoms arising from glutamate hypofunction, including cognitive impairments. Although increased KYNA levels reduce excitatory neurotransmission, KYNA has been proposed to act as an endogenous antagonist at the glycine site of the glutamate NMDA receptor (NMDAR) and as a negative allosteric modulator at the ?7 nicotinic acetylcholine receptor. Levels of KYNA are elevated in CSF and the postmortem brain of schizophrenia patients, and these elevated levels of KYNA could contribute to NMDAR hypofunction and the cognitive deficits and negative symptoms associated with this disease. However, the impact of endogenously produced KYNA on brain function and behavior is less well understood due to a paucity of pharmacological tools. To address this issue, we identified PF-04859989, a brain-penetrable inhibitor of kynurenine aminotransferase II (KAT II), the enzyme responsible for most brain KYNA synthesis. In rats, systemic administration of PF-04859989 dose-dependently reduced brain KYNA to as little as 28% of basal levels, and prevented amphetamine- and ketamine-induced disruption of auditory gating and improved performance in a sustained attention task. It also prevented ketamine-induced disruption of performance in a working memory task and a spatial memory task in rodents and nonhuman primates, respectively. Together, these findings support the hypotheses that endogenous KYNA impacts cognitive function and that inhibition of KAT II, and consequent lowering of endogenous brain KYNA levels, improves cognitive performance under conditions considered relevant for schizophrenia. PMID:25100593

Kozak, Rouba; Campbell, Brian M; Strick, Christine A; Horner, Weldon; Hoffmann, William E; Kiss, Tamas; Chapin, Douglas S; McGinnis, Dina; Abbott, Amanda L; Roberts, Brooke M; Fonseca, Kari; Guanowsky, Victor; Young, Damon A; Seymour, Patricia A; Dounay, Amy; Hajos, Mihaly; Williams, Graham V; Castner, Stacy A

2014-08-01

176

Microwave beamforming for non-invasive patient-specific hyperthermia treatment of pediatric brain cancer  

E-print Network

-invasive patient-specific hyperthermia treatment of pediatric brain cancer Matthew J Burfeindt1 , Earl Zastrow1Microwave beamforming for non-invasive patient-specific hyperthermia treatment of pediatric brain cancer This article has been downloaded from IOPscience. Please scroll down to see the full text article

Sheridan, Jennifer

177

Functional Brain Network Changes Associated with Maintenance of Cognitive Function in Multiple Sclerosis  

PubMed Central

In multiple sclerosis (MS) functional changes in connectivity due to cortical reorganization could lead to cognitive impairment (CI), or reflect a re-adjustment to reduce the clinical effects of widespread tissue damage. Such alterations in connectivity could result in changes in neural activation as assayed by executive function tasks. We examined cognitive function in MS patients with mild to moderate CI and age-matched controls. We evaluated brain activity using functional magnetic resonance imaging (fMRI) during the successful performance of the Wisconsin card sorting (WCS) task by MS patients, showing compensatory maintenance of normal function, as measured by response latency and error rate. To assess changes in functional connectivity throughout the brain, we performed a global functional brain network analysis by computing voxel-by-voxel correlations on the fMRI time series data and carrying out a hierarchical cluster analysis. We found that during the WCS task there is a significant reduction in the number of smaller size brain functional networks, and a change in the brain areas representing the nodes of these networks in MS patients compared to age-matched controls. There is also a concomitant increase in the strength of functional connections between brain loci separated at intermediate-scale distances in these patients. These functional alterations might reflect compensatory neuroplastic reorganization underlying maintenance of relatively normal cognitive function in the face of white matter lesions and cortical atrophy produced by MS. PMID:21152340

Helekar, Santosh A.; Shin, Jae C.; Mattson, Brandi J.; Bartley, Krystle; Stosic, Milena; Saldana-King, Toni; Montague, P. Read; Hutton, George J.

2010-01-01

178

Temporally-independent functional modes of spontaneous brain activity.  

PubMed

Resting-state functional magnetic resonance imaging has become a powerful tool for the study of functional networks in the brain. Even "at rest," the brain's different functional networks spontaneously fluctuate in their activity level; each network's spatial extent can therefore be mapped by finding temporal correlations between its different subregions. Current correlation-based approaches measure the average functional connectivity between regions, but this average is less meaningful for regions that are part of multiple networks; one ideally wants a network model that explicitly allows overlap, for example, allowing a region's activity pattern to reflect one network's activity some of the time, and another network's activity at other times. However, even those approaches that do allow overlap have often maximized mutual spatial independence, which may be suboptimal if distinct networks have significant overlap. In this work, we identify functionally distinct networks by virtue of their temporal independence, taking advantage of the additional temporal richness available via improvements in functional magnetic resonance imaging sampling rate. We identify multiple "temporal functional modes," including several that subdivide the default-mode network (and the regions anticorrelated with it) into several functionally distinct, spatially overlapping, networks, each with its own pattern of correlations and anticorrelations. These functionally distinct modes of spontaneous brain activity are, in general, quite different from resting-state networks previously reported, and may have greater biological interpretability. PMID:22323591

Smith, Stephen M; Miller, Karla L; Moeller, Steen; Xu, Junqian; Auerbach, Edward J; Woolrich, Mark W; Beckmann, Christian F; Jenkinson, Mark; Andersson, Jesper; Glasser, Matthew F; Van Essen, David C; Feinberg, David A; Yacoub, Essa S; Ugurbil, Kamil

2012-02-21

179

Neurosteroid Biosynthesis and Function in the Brain of Domestic Birds  

PubMed Central

It is now established that the brain and other nervous systems have the capability of forming steroids de novo, the so-called “neurosteroids.” The pioneering discovery of Baulieu and his colleagues, using rodents, has opened the door to a new research field of “neurosteroids.” In contrast to mammalian vertebrates, little has been known regarding de novo neurosteroidogenesis in the brain of birds. We therefore investigated neurosteroid formation and metabolism in the brain of quail, a domestic bird. Our studies over the past two decades demonstrated that the quail brain possesses cytochrome P450 side-chain cleavage enzyme (P450scc), 3?-hydroxysteroid dehydrogenase/?5-?4-isomerase (3?-HSD), 5?-reductase, cytochrome P450 17?-hydroxylase/c17,20-lyase (P45017?,lyase), 17?-HSD, etc., and produces pregnenolone, progesterone, 5?-dihydroprogesterone (5?-DHP), 3?, 5?-tetrahydroprogesterone (3?, 5?-THP), androstenedione, testosterone, and estradiol from cholesterol. Independently, Schlinger’s laboratory demonstrated that the brain of zebra finch, a songbird, also produces various neurosteroids. Thus, the formation and metabolism of neurosteroids from cholesterol is now known to occur in the brain of birds. In addition, we recently found that the quail brain expresses cytochrome P4507? and produces 7?- and 7?-hydroxypregnenolone, previously undescribed avian neurosteroids, from pregnenolone. This paper summarizes the advances made in our understanding of neurosteroid formation and metabolism in the brain of domestic birds. This paper also describes what are currently known about physiological changes in neurosteroid formation and biological functions of neurosteroids in the brain of domestic and other birds. PMID:22645509

Tsutsui, Kazuyoshi

2011-01-01

180

Genetics of brain function and cognition  

Microsoft Academic Search

There is overwhelming evidence for the existence of substantial genetic influences on individ- ual differences in general and specific cognitive abilities, especially in adults. The actual local- ization and identification of genes underlying variation in cognitive abilities and intelligence has only just started, however. Successes are currently limited to neurological mutations with rather severe cognitive effects. The current approaches to

Geus de E. J. C; Margaret J. Wright; Nicholas G. Martin; Dorret I. Boomsma

2001-01-01

181

Linking human brain local activity fluctuations to structural and functional network architectures  

PubMed Central

Activity of cortical local neuronal populations fluctuates continuously, and a large proportion of these fluctuations are shared across populations of neurons. Here we seek organizational rules that link these two phenomena. Using neuronal activity, as identified by functional MRI (fMRI) and for a given voxel or brain region, we derive a single measure of full bandwidth brain-oxygenation-level-dependent (BOLD) fluctuations by calculating the slope, ?, for the log-linear power spectrum. For the same voxel or region, we also measure the temporal coherence of its fluctuations to other voxels or regions, based on exceeding a given threshold, ?, for zero lag correlation, establishing functional connectivity between pairs of neuronal populations. From resting state fMRI, we calculated whole-brain group-averaged maps for ? and for functional connectivity. Both maps showed similar spatial organization, with a correlation coefficient of 0.75 between the two parameters across all brain voxels, as well as variability with hodology. A computational model replicated the main results, suggesting that synaptic low-pass filtering can account for these interrelationships. We also investigated the relationship between ? and structural connectivity, as determined by diffusion tensor imaging-based tractography. We observe that the correlation between ? and connectivity depends on attentional state; specifically, ? correlated more highly to structural connectivity during rest than while attending to a task. Overall, these results provide global rules for the dynamics between frequency characteristics of local brain activity and the architecture of underlying brain networks. PMID:23396160

Baria, A.T.; Mansour, A.; Huang, L.; Baliki, M.N.; Cecchi, G.A.; Mesulam, M.M.; Apkarian, A.V.

2013-01-01

182

Nutrition, brain function and cognitive performance  

Microsoft Academic Search

Military interest in the effects of nutritional factors on cognitive function has stimulated considerable research on a variety of food constituents. This paper will review the research on the amino acids tryptophan and tyrosine, caffeine and carbohydrate. It will focus on research that addresses the potential utility of these compounds in military applications, particularly the acute, as opposed to chronic,

Harris R Lieberman

2003-01-01

183

Hintz et al, Real-time neonatal optical functional brain imaging 335 J. Perinat. Med. Bedside functional imaging of the premature infant brain  

E-print Network

functional imaging of the premature infant brain 29 (2001) 335 343 during passive motor activation Susan R- aging techniques have come to the fore, which use brain metabolite concentration to map brain func- tion of the premature infant brain in the NICU using near-infrared technology. 2 Methods 2.1 DOTS Device Several years

184

MR anatomy of deep brain nuclei with special reference to specific diseases and deep brain stimulation localization.  

PubMed

Diseases affecting the basal ganglia and deep brain structures vary widely in etiology and include metabolic, infectious, ischemic, and neurodegenerative conditions. Some neurologic diseases, such as Wernicke encephalopathy or pseudohypoparathyroidism, require specific treatments, which if unrecognized could lead to further complications. Other pathologies, such as hypertrophic olivary degeneration, if not properly diagnosed may be mistaken for a primary medullary neoplasm and create unnecessary concern. The deep brain structures are complex and can be difficult to distinguish on routine imaging. It is imperative that radiologists first understand the intrinsic anatomic relationships between the different basal ganglia nuclei and deep brain structures with magnetic resonance (MR) imaging. It is important to understand the "normal" MR signal characteristics, locations, and appearances of these structures. This is essential to recognizing diseases affecting the basal ganglia and deep brain structures, especially since most of these diseases result in symmetrical, and therefore less noticeable, abnormalities. It is also crucial that neurosurgeons correctly identify the deep brain nuclei presurgically for positioning deep brain stimulator leads, the most important being the subthalamic nucleus for Parkinson syndromes and the thalamic ventral intermediate nucleus for essential tremor. Radiologists will be able to better assist clinicians in diagnosis and treatment once they are able to accurately localize specific deep brain structures. PMID:24571832

Telford, Ryan; Vattoth, Surjith

2014-02-01

185

Fluctuations in Neuronal Activity: Clues to Brain Function  

NASA Astrophysics Data System (ADS)

Recordings from neuronal preparations, either in vitro or in the intact brain, are characterized by fluctuations, what is commonly considered as "noise". Due to the current recording and analysis methods, it is not feasible to separate what we term noise, from the "meaningful" neuronal activity. We propose that fluctuations serve to maintain brain activity in an optimal state for cognitive processing, not allowing it to fall into long-term periodic behaviour. We have studied fluctuations in magnetoencephalographic (MEG) recordings from normal subjects and epileptic patients, in electroencephalographic (EEG) recordings from children with impact injury, as well as in intracerebral electrophysiological recordings in freely moving rats. Specifically, we have determined phase locking patterns between brain areas from these recordings, which display fluctuations at different scales. We submit the idea that the variability in phase synchronization affords a more complete search of all possible phase differences in a hypothetical phase-locking state space that contributes to brain information processing. In brain pathologies, like epileptiform activity here studied, different levels of fluctuations in phase synchrony may favour the generation of stable synchronized states that characterize epileptic seizures. While the border between noise and high-dimensional dynamics is fuzzy, the scrutiny of neuronal fluctuations at different levels will provide important insights to the unravelling of the relation between brain and behaviour.

Pérez Velazquez, José L.; Guevara, Ramón; Belkas, Jason; Wennberg, Richard; Senjanoviè, Goran; García Dominguez, Luis

2005-08-01

186

Surrogate-assisted analysis of weighted functional brain networks  

E-print Network

Graph-theoretical analyses of complex brain networks is a rapidly evolving field with a strong impact for neuroscientific and related clinical research. Due to a number of confounding variables, however, a reliable and meaningful characterization of particularly functional brain networks is a major challenge. Addressing this problem, we present an analysis approach for weighted networks that makes use of surrogate networks with preserved edge weights or vertex strengths. We first investigate whether characteristics of weighted networks are influenced by trivial properties of the edge weights or vertex strengths (e.g., their standard deviations). If so, these influences are then effectively segregated with an appropriate surrogate normalization of the respective network characteristic. We demonstrate this approach by re-examining, in a time-resolved manner, weighted functional brain networks of epilepsy patients and control subjects derived from simultaneous EEG/MEG recordings during different behavioral state...

Ansmann, Gerrit

2014-01-01

187

Experience induces functional reorganization in brain regions involved in odor imagery in perfumers.  

PubMed

Areas of expertise that cultivate specific sensory domains reveal the brain's ability to adapt to environmental change. Perfumers are a small population who claim to have a unique ability to generate olfactory mental images. To evaluate the impact of this expertise on the brain regions involved in odor processing, we measured brain activity in novice and experienced (student and professional) perfumers while they smelled or imagined odors. We demonstrate that olfactory imagery activates the primary olfactory (piriform) cortex (PC) in all perfumers, demonstrating that similar neural substrates were activated in odor perception and imagination. In professional perfumers, extensive olfactory practice influences the posterior PC, the orbitofrontal cortex, and the hippocampus; during the creation of mental images of odors, the activity in these areas was negatively correlated with experience. Thus, the perfumers' expertise is associated with a functional reorganization of key olfactory and memory brain regions, explaining their extraordinary ability to imagine odors and create fragrances. PMID:21391264

Plailly, Jane; Delon-Martin, Chantal; Royet, Jean-Pierre

2012-01-01

188

Sustained deep-tissue pain alters functional brain connectivity  

PubMed Central

Recent functional brain connectivity studies have contributed to our understanding of the neurocircuitry supporting pain perception. However, evoked-pain connectivity studies have employed cutaneous and/or brief stimuli, which induce sensations that differ appreciably from the clinical pain experience. Sustained myofascial pain evoked by pressure cuff affords an excellent opportunity to evaluate functional connectivity change to more clinically-relevant sustained deep-tissue pain. Connectivity in specific networks known to be modulated by evoked pain (sensorimotor, salience, dorsal attention, fronto-parietal control and default mode networks; SMN, SLN, DAN, FCN and DMN) was evaluated with functional-connectivity MRI, both at rest and during a sustained (6-minute) pain state in healthy adults. We found that pain was stable with no significant changes of subjects’ pain ratings over the stimulation period. Sustained pain reduced connectivity between the SMN and the contralateral leg primary sensorimotor (S1/M1) representation. Such SMN-S1/M1 connectivity decreases were also accompanied by and correlated with increased SLN-S1/M1 connectivity, suggesting recruitment of activated S1/M1 from SMN to SLN. Sustained pain also increased DAN connectivity to pain processing regions such as mid-cingulate cortex, posterior insula and putamen. Moreover, greater connectivity during pain between contralateral S1/M1 and posterior insula, thalamus, putamen, and amygdala, was associated with lower cuff pressures needed to reach the targeted pain sensation. These results demonstrate that sustained pain disrupts resting S1/M1 connectivity by shifting it to a network known to process stimulus salience. Furthermore, increased connectivity between S1/M1 and both sensory and affective processing areas may be an important contribution to inter-individual differences in pain sensitivity. PMID:23718988

Kim, Jieun; Loggia, Marco L.; Edwards, Robert; Wasan, Ajay D.; Gollub, Randy L.; Napadow, Vitaly

2013-01-01

189

The Role of Noise in Brain Function  

NASA Astrophysics Data System (ADS)

Noise plays a fundamental role in all living organisms from the earliest prokaryotes to advanced mammalian forms, such as ourselves. In the context of living organisms, the term 'noise' usually refers to the variance amongst measurements obtained from repeated identical experimental conditions, or from output signals from these systems. It is noteworthy that both these conditions are universally characterized by the presence of background fluctuations. In non-biological systems, such as electronics or in communications sciences, where the aim is to send error-free messages, noise was generally regarded as a problem. The discovery of Stochastic Resonances (SR) in non-linear dynamics brought a shift of perception where noise, rather than representing a problem, became fundamental to system function, especially so in biology. The question now is: to what extent is biological function dependent on random noise. Indeed, it seems feasible that noise also plays an important role in neuronal communication and oscillatory synchronization. Given this approach, it follows that determining Fisher information content could be relevant in neuronal communication. It also seems possible that the principle of least time, and that of the sum over histories, could be important basic principles in understanding the coherence dynamics responsible for action and perception. Ultimately, external noise cancellation combined with intrinsic noise signal embedding and, the use of the principle of least time may be considered an essential step in the organization of central nervous system (CNS) function.

Roy, S.; Llinás, R.

2012-12-01

190

Brain endothelial cell specific integrins and ischemic stroke.  

PubMed

Ischemic stroke, a devastating event caused by the blockage of a blood vessel(s) supplying the brain, continues to affect thousands of people in the USA every year. While no true advances in stroke therapy have arisen to further improve patient outcomes since the introduction of the blood clot buster tissue plasminogen activator and mechanical clot removal, fewer people are dying from the immediate stroke insult. Instead, patients often suffer significant morbidity due to post-recanalization secondary damage. Central to this damage is the breakdown of the blood-brain barrier, which, in addition to contributing to edema and inflammation, triggers an upregulation in angiogenic growth factors in the brain's attempt to salvage and repair itself. Recent studies have begun to improve our understanding of the post-stroke angiogenic response of brain endothelial cells in the ischemic penumbra, which has long been held to be an important site for medical intervention. These studies suggest that endothelial cell integrin matrix receptors play an important and therapeutically significant role in moderating cellular responses to ischemic brain injury. PMID:25262658

Guell, Kathleen; Bix, Gregory J

2014-11-01

191

Fine-grained mapping of mouse brain functional connectivity with resting-state fMRI.  

PubMed

Understanding the intrinsic circuit-level functional organization of the brain has benefited tremendously from the advent of resting-state fMRI (rsfMRI). In humans, resting-state functional network has been consistently mapped and its alterations have been shown to correlate with symptomatology of various neurological or psychiatric disorders. To date, deciphering the mouse brain functional connectivity (MBFC) with rsfMRI remains a largely underexplored research area, despite the plethora of human brain disorders that can be modeled in this specie. To pave the way from pre-clinical to clinical investigations we characterized here the intrinsic architecture of mouse brain functional circuitry, based on rsfMRI data acquired at 7T using the Cryoprobe technology. High-dimensional spatial group independent component analysis demonstrated fine-grained segregation of cortical and subcortical networks into functional clusters, overlapping with high specificity onto anatomical structures, down to single gray matter nuclei. These clusters, showing a high level of stability and reliability in their patterning, formed the input elements for computing the MBFC network using partial correlation and graph theory. Its topological architecture conserved the fundamental characteristics described for the human and rat brain, such as small-worldness and partitioning into functional modules. Our results additionally showed inter-modular interactions via "network hubs". Each major functional system (motor, somatosensory, limbic, visual, autonomic) was found to have representative hubs that might play an important input/output role and form a functional core for information integration. Moreover, the rostro-dorsal hippocampus formed the highest number of relevant connections with other brain areas, highlighting its importance as core structure for MBFC. PMID:24718287

Mechling, Anna E; Hübner, Neele S; Lee, Hsu-Lei; Hennig, Jürgen; von Elverfeldt, Dominik; Harsan, Laura-Adela

2014-08-01

192

"Hotheaded": the role OF TRPV1 in brain functions.  

PubMed

The TRPV1 (vanilloid 1) channel is best known for its role in sensory transmission in the nociceptive neurons of the peripheral nervous system. Although first studied in the dorsal root ganglia as the receptor for capsaicin, TRPV1 has been recently recognized to have a broader distribution in the central nervous system, where it is likely to constitute an atypical neurotransmission system involved in several functions through modulation of both neuronal and glial activities. The endovanilloid-activated brain TRPV1 channels seem to be involved in somatosensory, motor and visceral functions. Recent studies suggested that TRPV1 channels also account for more complex functions, as addiction, anxiety, mood and cognition/learning. However, more studies are needed before the relevance of TRPV1 in brain activity can be clearly stated. This review highlights the increasing importance of TRPV1 as a regulator of brain function and discusses possible bases for the future development of new therapeutic approaches that by targeting brain TRPV1 receptors might be used for the treatment of several neurological disorders. PMID:24887171

Martins, D; Tavares, I; Morgado, C

2014-10-01

193

Optimizing Experimental Design for Comparing Models of Brain Function  

Microsoft Academic Search

This article presents the first attempt to formalize the optimization of experimental design with the aim of comparing models of brain function based on neuroimaging data. We demonstrate our approach in the context of Dynamic Causal Modelling (DCM), which relates experimental manipulations to observed network dynamics (via hidden neuronal states) and provides an inference framework for selecting among candidate models.

Jean Daunizeau; Kerstin Preuschoff; Karl Friston; Klaas Stephan

2011-01-01

194

Functional brain mapping of the relaxation response and meditation  

Microsoft Academic Search

Meditation is a conscious mental process that induces a set of integrated physiologic changes termed the relaxation response. Functional magnetic resonance imaging (fMRI) was used to identify and characterize the brain regions that are active during a simple form of meditation. Significant ( p , 10?7) signal increases were observed in the group-averaged data in the dorsolateral prefrontal and parietal

Sara W. Lazar; George Bush; Randy L. Gollub; Gregory L. Fricchione; Gurucharan Khalsa; Herbert Benson

2000-01-01

195

ARCHIVAL REPORT Functional Brain Activation to Emotionally Valenced  

E-print Network

to patterns found in adults and adolescents with major depression. These patterns were most strongly related to as preschool-onset depression (PO-MDD) (4­7). Adults and adolescents with MDD show altered functional brain with a History of Preschool-Onset Major Depression Deanna M. Barch, Michael S. Gaffrey, Kelly N. Botteron, Andrew

196

Investigating the Dynamics of Functional Brain Networks with MRI  

NASA Astrophysics Data System (ADS)

Functional Magnetic Resonance Imaging (fMRI) is sensitive to changes in blood oxygenation levels. While fMRI has traditionally mapped changes in these levels that localize to brain areas activated by an external stimulus, recent work has focused on detecting correlated, non-stimulus-related fluctuations in the fMRI signal throughout the brain. These fluctuations are believed to arise from spontaneous variations in local neural activity, and so correlated fluctuations from different brain areas may indicate coordinated activity. Maps of ``functional connectivity'' based upon these fluctuations show reproducible patterns of correlated signals. To date, research has focused on steady-state networks that persist over the entire imaging session (minutes). We are exploring the possibility of detecting changes in network activity on much shorter time scales (seconds). Preliminary analysis shows that power in the frequency band used to map functional connectivity varies over time, and that power differences correspond to changes in correlation between areas. We also detected phase differences in fluctuations that are consistent with propagating waves. These results indicate that time-varying analysis of fMRI data may provide insight into the dynamics of functional networks in the brain.

Keilholz, Shella; Majeed, Waqas

2008-03-01

197

Functional craniology and brain evolution: from paleontology to biomedicine.  

PubMed

Anatomical systems are organized through a network of structural and functional relationships among their elements. This network of relationships is the result of evolution, it represents the actual target of selection, and it generates the set of rules orienting and constraining the morphogenetic processes. Understanding the relationship among cranial and cerebral components is necessary to investigate the factors that have influenced and characterized our neuroanatomy, and possible drawbacks associated with the evolution of large brains. The study of the spatial relationships between skull and brain in the human genus has direct relevance in cranial surgery. Geometrical modeling can provide functional perspectives in evolution and brain physiology, like in simulations to investigate metabolic heat production and dissipation in the endocranial form. Analysis of the evolutionary constraints between facial and neural blocks can provide new information on visual impairment. The study of brain form variation in fossil humans can supply a different perspective for interpreting the processes behind neurodegeneration and Alzheimer's disease. Following these examples, it is apparent that paleontology and biomedicine can exchange relevant information and contribute at the same time to the development of robust evolutionary hypotheses on brain evolution, while offering more comprehensive biological perspectives with regard to the interpretation of pathological processes. PMID:24765064

Bruner, Emiliano; de la Cuétara, José Manuel; Masters, Michael; Amano, Hideki; Ogihara, Naomichi

2014-01-01

198

Memory Function Before and After Whole Brain Radiotherapy in Patients With and Without Brain Metastases  

SciTech Connect

Purpose: To prospectively compare the effect of prophylactic and therapeutic whole brain radiotherapy (WBRT) on memory function in patients with and without brain metastases. Methods and Materials: Adult patients with and without brain metastases (n = 44) were prospectively evaluated with serial cognitive testing, before RT (T0), after starting RT (T1), at the end of RT (T2), and 6-8 weeks (T3) after RT completion. Data were obtained from small-cell lung cancer patients treated with prophylactic cranial irradiation, patients with brain metastases treated with therapeutic cranial irradiation (TCI), and breast cancer patients treated with RT to the breast. Results: Before therapy, prophylactic cranial irradiation patients performed worse than TCI patients or than controls on most test scores. During and after WBRT, verbal memory function was influenced by pretreatment cognitive status (p < 0.001) and to a lesser extent by WBRT. Acute (T1) radiation effects on verbal memory function were only observed in TCI patients (p = 0.031). Subacute (T3) radiation effects on verbal memory function were observed in both TCI and prophylactic cranial irradiation patients (p = 0.006). These effects were more pronounced in patients with above-average performance at baseline. Visual memory and attention were not influenced by WBRT. Conclusions: The results of our study have shown that WBRT causes cognitive dysfunction immediately after the beginning of RT in patients with brain metastases only. At 6-8 weeks after the end of WBRT, cognitive dysfunction was seen in patients with and without brain metastases. Because cognitive dysfunction after WBRT is restricted to verbal memory, patients should not avoid WBRT because of a fear of neurocognitive side effects.

Welzel, Grit [Department of Radiation Oncology, University Medical Center Mannheim, University of Heidelberg, Mannheim (Germany)], E-mail: grit.welzel@radonk.ma.uni-heidelberg.de; Fleckenstein, Katharina [Department of Radiation Oncology, University Medical Center Mannheim, University of Heidelberg, Mannheim (Germany); Department of Radiation Oncology, Duke University Medical Center, Durham, NC (United States); Schaefer, Joerg; Hermann, Brigitte; Kraus-Tiefenbacher, Uta; Mai, Sabine K.; Wenz, Frederik [Department of Radiation Oncology, University Medical Center Mannheim, University of Heidelberg, Mannheim (Germany)

2008-12-01

199

Brain-specific interleukin-1 receptor accessory protein in sleep regulation.  

PubMed

Interleukin (IL)-1? is involved in several brain functions, including sleep regulation. It promotes non-rapid eye movement (NREM) sleep via the IL-1 type I receptor. IL-1?/IL-1 receptor complex signaling requires adaptor proteins, e.g., the IL-1 receptor brain-specific accessory protein (AcPb). We have cloned and characterized rat AcPb, which shares substantial homologies with mouse AcPb and, compared with AcP, is preferentially expressed in the brain. Furthermore, rat somatosensory cortex AcPb mRNA varied across the day with sleep propensity, increased after sleep deprivation, and was induced by somnogenic doses of IL-1?. Duration of NREM sleep was slightly shorter and duration of REM sleep was slightly longer in AcPb knockout than wild-type mice. In response to lipopolysaccharide, which is used to induce IL-1?, sleep responses were exaggerated in AcPb knockout mice, suggesting that, in normal mice, inflammation-mediated sleep responses are attenuated by AcPb. We conclude that AcPb has a role in sleep responses to inflammatory stimuli and, possibly, in physiological sleep regulation. PMID:22174404

Taishi, Ping; Davis, Christopher J; Bayomy, Omar; Zielinski, Mark R; Liao, Fan; Clinton, James M; Smith, Dirk E; Krueger, James M

2012-03-01

200

The Functional Connectivity Landscape of the Human Brain  

PubMed Central

Functional brain networks emerge and dissipate over a primarily static anatomical foundation. The dynamic basis of these networks is inter-regional communication involving local and distal regions. It is assumed that inter-regional distances play a pivotal role in modulating network dynamics. Using three different neuroimaging modalities, 6 datasets were evaluated to determine whether experimental manipulations asymmetrically affect functional relationships based on the distance between brain regions in human participants. Contrary to previous assumptions, here we show that short- and long-range connections are equally likely to strengthen or weaken in response to task demands. Additionally, connections between homotopic areas are the most stable and less likely to change compared to any other type of connection. Our results point to a functional connectivity landscape characterized by fluid transitions between local specialization and global integration. This ability to mediate functional properties irrespective of spatial distance may engender a diverse repertoire of cognitive processes when faced with a dynamic environment. PMID:25350370

Fatima, Zainab; Jonides, John; McIntosh, Anthony R.

2014-01-01

201

The functional connectivity landscape of the human brain.  

PubMed

Functional brain networks emerge and dissipate over a primarily static anatomical foundation. The dynamic basis of these networks is inter-regional communication involving local and distal regions. It is assumed that inter-regional distances play a pivotal role in modulating network dynamics. Using three different neuroimaging modalities, 6 datasets were evaluated to determine whether experimental manipulations asymmetrically affect functional relationships based on the distance between brain regions in human participants. Contrary to previous assumptions, here we show that short- and long-range connections are equally likely to strengthen or weaken in response to task demands. Additionally, connections between homotopic areas are the most stable and less likely to change compared to any other type of connection. Our results point to a functional connectivity landscape characterized by fluid transitions between local specialization and global integration. This ability to mediate functional properties irrespective of spatial distance may engender a diverse repertoire of cognitive processes when faced with a dynamic environment. PMID:25350370

Miši?, Bratislav; Fatima, Zainab; Askren, Mary K; Buschkuehl, Martin; Churchill, Nathan; Cimprich, Bernadine; Deldin, Patricia J; Jaeggi, Susanne; Jung, Misook; Korostil, Michele; Kross, Ethan; Krpan, Katherine M; Peltier, Scott; Reuter-Lorenz, Patricia A; Strother, Stephen C; Jonides, John; McIntosh, Anthony R; Berman, Marc G

2014-01-01

202

Resting state functional MRI in Parkinson's disease: the impact of deep brain stimulation on 'effective' connectivity  

PubMed Central

Depleted of dopamine, the dynamics of the parkinsonian brain impact on both ‘action’ and ‘resting’ motor behaviour. Deep brain stimulation has become an established means of managing these symptoms, although its mechanisms of action remain unclear. Non-invasive characterizations of induced brain responses, and the effective connectivity underlying them, generally appeals to dynamic causal modelling of neuroimaging data. When the brain is at rest, however, this sort of characterization has been limited to correlations (functional connectivity). In this work, we model the ‘effective’ connectivity underlying low frequency blood oxygen level-dependent fluctuations in the resting Parkinsonian motor network—disclosing the distributed effects of deep brain stimulation on cortico-subcortical connections. Specifically, we show that subthalamic nucleus deep brain stimulation modulates all the major components of the motor cortico-striato-thalamo-cortical loop, including the cortico-striatal, thalamo-cortical, direct and indirect basal ganglia pathways, and the hyperdirect subthalamic nucleus projections. The strength of effective subthalamic nucleus afferents and efferents were reduced by stimulation, whereas cortico-striatal, thalamo-cortical and direct pathways were strengthened. Remarkably, regression analysis revealed that the hyperdirect, direct, and basal ganglia afferents to the subthalamic nucleus predicted clinical status and therapeutic response to deep brain stimulation; however, suppression of the sensitivity of the subthalamic nucleus to its hyperdirect afferents by deep brain stimulation may subvert the clinical efficacy of deep brain stimulation. Our findings highlight the distributed effects of stimulation on the resting motor network and provide a framework for analysing effective connectivity in resting state functional MRI with strong a priori hypotheses. PMID:24566670

Kahan, Joshua; Urner, Maren; Moran, Rosalyn; Flandin, Guillaume; Marreiros, Andre; Mancini, Laura; White, Mark; Thornton, John; Yousry, Tarek; Zrinzo, Ludvic; Hariz, Marwan; Limousin, Patricia; Friston, Karl

2014-01-01

203

Anatomical correlates for category-specific naming of objects and actions: a brain stimulation mapping study.  

PubMed

The production of object and action words can be dissociated in aphasics, yet their anatomical correlates have been difficult to distinguish in functional imaging studies. To investigate the extent to which the cortical neural networks underlying object- and action-naming processing overlap, we performed electrostimulation mapping (ESM), which is a neurosurgical mapping technique routinely used to examine language function during brain-tumor resections. Forty-one right-handed patients who had surgery for a brain tumor were asked to perform overt naming of object and action pictures under stimulation. Overall, 73 out of the 633 stimulated cortical sites (11.5%) were associated with stimulation-induced language interferences. These interference sites were very much localized (<1 cm(2) ), and showed substantial variability across individuals in their exact localization. Stimulation interfered with both object and action naming over 44 sites, whereas it specifically interfered with object naming over 19 sites and with action naming over 10 sites. Specific object-naming sites were mainly identified in Broca's area (Brodmann area 44/45) and the temporal cortex, whereas action-naming specific sites were mainly identified in the posterior midfrontal gyrus (Brodmann area 6/9) and Broca's area (P = 0.003 by the Fisher's exact test). The anatomical loci we emphasized are in line with a cortical distinction between objects and actions based on conceptual/semantic features, so the prefrontal/premotor cortex would preferentially support sensorimotor contingencies associated with actions, whereas the temporal cortex would preferentially underpin (functional) properties of objects. PMID:23015527

Lubrano, Vincent; Filleron, Thomas; Démonet, Jean-François; Roux, Franck-Emmanuel

2014-02-01

204

Repetitive Transcranial Magnetic Stimulation Activates Specific Regions in Rat Brain  

NASA Astrophysics Data System (ADS)

Repetitive transcranial magnetic stimulation (rTMS) is a noninvasive technique to induce electric currents in the brain. Although rTMS is being evaluated as a possible alternative to electroconvulsive therapy for the treatment of refractory depression, little is known about the pattern of activation induced in the brain by rTMS. We have compared immediate early gene expression in rat brain after rTMS and electroconvulsive stimulation, a well-established animal model for electroconvulsive therapy. Our result shows that rTMS applied in conditions effective in animal models of depression induces different patterns of immediate-early gene expression than does electroconvulsive stimulation. In particular, rTMS evokes strong neural responses in the paraventricular nucleus of the thalamus (PVT) and in other regions involved in the regulation of circadian rhythms. The response in PVT is independent of the orientation of the stimulation probe relative to the head. Part of this response is likely because of direct activation, as repetitive magnetic stimulation also activates PVT neurons in brain slices.

Ji, Ru-Rong; Schlaepfer, Thomas E.; Aizenman, Carlos D.; Epstein, Charles M.; Qiu, Dike; Huang, Justin C.; Rupp, Fabio

1998-12-01

205

Specific Ways Brain SPECT Imaging Enhances Clinical Psychiatric Practice  

Microsoft Academic Search

Our objective was to ascertain in a prospective case series how often brain single photon emission computed tomography (SPECT) neuroimaging adds relevant information for diagnosis and\\/or treatment beyond current standard assessment tools in complex psychiatric cases. Charts of 109 consecutively evaluated outpatients from four psychiatrics clinics that routinely utilize SPECT imaging for complex cases were analyzed in two stages. In

Daniel G. Amen; Diane Highum; Robert Licata; Joseph A. Annibali; Lillian Somner; H. Edmund Pigott; Derek V. Taylor; Manuel Trujillo; Andrew Newberg; Theodore Henderson; Kristen Willeumier

2012-01-01

206

Altered functional and structural brain network organization in autism.  

PubMed

Structural and functional underconnectivity have been reported for multiple brain regions, functional systems, and white matter tracts in individuals with autism spectrum disorders (ASD). Although recent developments in complex network analysis have established that the brain is a modular network exhibiting small-world properties, network level organization has not been carefully examined in ASD. Here we used resting-state functional MRI (n = 42 ASD, n = 37 typically developing; TD) to show that children and adolescents with ASD display reduced short and long-range connectivity within functional systems (i.e., reduced functional integration) and stronger connectivity between functional systems (i.e., reduced functional segregation), particularly in default and higher-order visual regions. Using graph theoretical methods, we show that pairwise group differences in functional connectivity are reflected in network level reductions in modularity and clustering (local efficiency), but shorter characteristic path lengths (higher global efficiency). Structural networks, generated from diffusion tensor MRI derived fiber tracts (n = 51 ASD, n = 43 TD), displayed lower levels of white matter integrity yet higher numbers of fibers. TD and ASD individuals exhibited similar levels of correlation between raw measures of structural and functional connectivity (n = 35 ASD, n = 35 TD). However, a principal component analysis combining structural and functional network properties revealed that the balance of local and global efficiency between structural and functional networks was reduced in ASD, positively correlated with age, and inversely correlated with ASD symptom severity. Overall, our findings suggest that modeling the brain as a complex network will be highly informative in unraveling the biological basis of ASD and other neuropsychiatric disorders. PMID:24179761

Rudie, J D; Brown, J A; Beck-Pancer, D; Hernandez, L M; Dennis, E L; Thompson, P M; Bookheimer, S Y; Dapretto, M

2012-01-01

207

The Anatomical Distance of Functional Connections Predicts Brain Network Topology in Health and Schizophrenia  

PubMed Central

The human brain is a topologically complex network embedded in anatomical space. Here, we systematically explored relationships between functional connectivity, complex network topology, and anatomical (Euclidean) distance between connected brain regions, in the resting-state functional magnetic resonance imaging brain networks of 20 healthy volunteers and 19 patients with childhood-onset schizophrenia (COS). Normal between-subject differences in average distance of connected edges in brain graphs were strongly associated with variation in topological properties of functional networks. In addition, a club or subset of connector hubs was identified, in lateral temporal, parietal, dorsal prefrontal, and medial prefrontal/cingulate cortical regions. In COS, there was reduced strength of functional connectivity over short distances especially, and therefore, global mean connection distance of thresholded graphs was significantly greater than normal. As predicted from relationships between spatial and topological properties of normal networks, this disorder-related proportional increase in connection distance was associated with reduced clustering and modularity and increased global efficiency of COS networks. Between-group differences in connection distance were localized specifically to connector hubs of multimodal association cortex. In relation to the neurodevelopmental pathogenesis of schizophrenia, we argue that the data are consistent with the interpretation that spatial and topological disturbances of functional network organization could arise from excessive “pruning” of short-distance functional connections in schizophrenia. PMID:22275481

Vertes, Petra E.; Stidd, Reva; Lalonde, Francois; Clasen, Liv; Rapoport, Judith; Giedd, Jay; Bullmore, Edward T.; Gogtay, Nitin

2013-01-01

208

Functional brain imaging in gastroenterology: to new beginnings.  

PubMed

With more than 100 studies published over the past two decades, functional brain imaging research in gastroenterology has become an established field; one that has enabled improved insight into the supraspinal responses evoked by gastrointestinal stimulation both in health and disease. However, there remains considerable inter-study variation in the published results, largely owing to methodological differences in stimulation and recording techniques, heterogeneous patient selection, lack of control for psychological factors and so on. These issues with reproducibility, although not unique to studies of the gastrointestinal tract, can lead to unjustified inferences. To obtain consistent and more clinically relevant results, there is a need to optimize and standardize brain imaging studies across different centres. In addition, the use of complementary and more novel brain imaging modalities and analyses, which are now being used in other fields of research, might help unravel the factors at play in functional gastrointestinal disorders. This Review highlights the areas in which functional brain imaging has been useful and what it has revealed, the areas that are in need of improvement, and finally suggestions for future directions. PMID:24912384

Al Omran, Yasser; Aziz, Qasim

2014-09-01

209

The change of functional connectivity specificity in rats under various anesthesia levels and its neural origin.  

PubMed

Spatiotemporal correlations of spontaneous blood oxygenation level dependent (BOLD) signals measured in the resting brain have been found to imply many resting-state coherent networks under both awake/conscious and anesthetized/unconscious conditions. To understand the resting-state brain networks in the unconscious state, spontaneous BOLD signals from the rat sensorimotor cortex were studied across a wide range of anesthesia levels induced by isoflurane. Distinct resting-state networks covering functionally specific sub-regions of the sensorimotor system were observed under light anesthesia with 1.0% isoflurane; however, they gradually merged into a highly synchronized and spatially less-specific network under deep anesthesia with 1.8% isoflurane. The EEG power correlations recorded using three electrodes from a separate group of rats showed similar dependency on anesthesia depth, suggesting the neural origin of the change in functional connectivity specificity. The specific-to-less-specific transition of resting-state networks may reflect a functional reorganization of the brain at different anesthesia levels or brain states. PMID:23208517

Liu, Xiao; Zhu, Xiao-Hong; Zhang, Yi; Chen, Wei

2013-07-01

210

The Change of Functional Connectivity Specificity in Rats Under Various Anesthesia Levels and its Neural Origin  

PubMed Central

Spatiotemporal correlations of spontaneous blood oxygenation level dependent (BOLD) signals measured in the resting brain have been found to imply many resting-state coherent networks under both awake/conscious and anesthetized/unconscious conditions. To understand the resting-state brain networks in the unconscious state, spontaneous BOLD signals from the rat sensorimotor cortex were studied across a wide range of anesthesia levels induced by isoflurane. Distinct resting-state networks covering functionally specific sub-regions of the sensorimotor system were observed under light anesthesia with 1.0 % isoflurane; however, they gradually merged into a highly synchronized and spatially less-specific network under deep anesthesia with 1.8 % isoflurane. The EEG power correlations recorded using three electrodes from a separate group of rats showed similar dependency on anesthesia depth, suggesting the neural origin of the change in functional connectivity specificity. The specific-to-less-specific transition of resting-state networks may reflect a functional reorganization of the brain at different anesthesia levels or brain states. PMID:23208517

Liu, Xiao; Zhu, Xiao-Hong; Zhang, Yi

2012-01-01

211

Zinc: An underappreciated modulatory factor of brain function.  

PubMed

The divalent cation, zinc is the second most abundant metal in the human body and is indispensable for life. Zinc concentrations must however, be tightly regulated as deficiencies are associated with multiple pathological conditions while an excess can be toxic. Zinc plays an important role as a cofactor in protein folding and function, e.g. catalytic interactions, DNA recognition by zinc finger proteins and modulation ion channel activity. There are 24 mammalian proteins specific for zinc transport that are subdivided in two groups with opposing functions: ZnT proteins reduce cytosolic zinc concentration while ZIP proteins increase it. The mammalian brain contains a significant amount of zinc, with 5-15% concentrated in synaptic vesicles of glutamatergic neurons alone. Accumulated in these vesicles by the ZnT3 transporter, zinc is released into the synaptic cleft at concentrations from nanomolar at rest to high micromolar during active neurotransmission. Low concentrations of zinc modulate the activity of a multitude of voltage- or ligand-gated ion channels, indicating that this divalent cation must be taken into account in the analysis of the pathophysiology of CNS disorders including epilepsy, schizophrenia and Alzheimer's disease. In the context of the latest findings, we review the role of zinc in the central nervous system and discuss the relevance of the most recent association between the zinc transporter, ZIP8 and schizophrenia. An enhanced understanding of zinc transporters in the context of ion channel modulation may offer new avenues in identifying novel therapeutic entities that target neurological disorders. PMID:25130547

Marger, L; Schubert, C R; Bertrand, D

2014-10-15

212

Partial sleep in the context of augmentation of brain function  

PubMed Central

Inability to solve complex problems or errors in decision making is often attributed to poor brain processing, and raises the issue of brain augmentation. Investigation of neuronal activity in the cerebral cortex in the sleep-wake cycle offers insights into the mechanisms underlying the reduction in mental abilities for complex problem solving. Some cortical areas may transit into a sleep state while an organism is still awake. Such local sleep would reduce behavioral ability in the tasks for which the sleeping areas are crucial. The studies of this phenomenon have indicated that local sleep develops in high order cortical areas. This is why complex problem solving is mostly affected by local sleep, and prevention of local sleep might be a potential way of augmentation of brain function. For this approach to brain augmentation not to entail negative consequences for the organism, it is necessary to understand the functional role of sleep. Our studies have given an unexpected answer to this question. It was shown that cortical areas that process signals from extero- and proprioreceptors during wakefulness, switch to the processing of interoceptive information during sleep. It became clear that during sleep all “computational power” of the brain is directed to the restoration of the vital functions of internal organs. These results explain the logic behind the initiation of total and local sleep. Indeed, a mismatch between the current parameters of any visceral system and the genetically determined normal range would provide the feeling of tiredness, or sleep pressure. If an environmental situation allows falling asleep, the organism would transit to a normal total sleep in all cortical areas. However, if it is impossible to go to sleep immediately, partial sleep may develop in some cortical areas in the still behaviorally awake organism. This local sleep may reduce both the “intellectual power” and the restorative function of sleep for visceral organs. PMID:24822040

Pigarev, Ivan N.; Pigareva, Marina L.

2014-01-01

213

Partial sleep in the context of augmentation of brain function.  

PubMed

Inability to solve complex problems or errors in decision making is often attributed to poor brain processing, and raises the issue of brain augmentation. Investigation of neuronal activity in the cerebral cortex in the sleep-wake cycle offers insights into the mechanisms underlying the reduction in mental abilities for complex problem solving. Some cortical areas may transit into a sleep state while an organism is still awake. Such local sleep would reduce behavioral ability in the tasks for which the sleeping areas are crucial. The studies of this phenomenon have indicated that local sleep develops in high order cortical areas. This is why complex problem solving is mostly affected by local sleep, and prevention of local sleep might be a potential way of augmentation of brain function. For this approach to brain augmentation not to entail negative consequences for the organism, it is necessary to understand the functional role of sleep. Our studies have given an unexpected answer to this question. It was shown that cortical areas that process signals from extero- and proprioreceptors during wakefulness, switch to the processing of interoceptive information during sleep. It became clear that during sleep all "computational power" of the brain is directed to the restoration of the vital functions of internal organs. These results explain the logic behind the initiation of total and local sleep. Indeed, a mismatch between the current parameters of any visceral system and the genetically determined normal range would provide the feeling of tiredness, or sleep pressure. If an environmental situation allows falling asleep, the organism would transit to a normal total sleep in all cortical areas. However, if it is impossible to go to sleep immediately, partial sleep may develop in some cortical areas in the still behaviorally awake organism. This local sleep may reduce both the "intellectual power" and the restorative function of sleep for visceral organs. PMID:24822040

Pigarev, Ivan N; Pigareva, Marina L

2014-01-01

214

The Mouse Blood-Brain Barrier Transcriptome: A New Resource for Understanding the Development and Function of Brain Endothelial Cells  

Microsoft Academic Search

The blood-brain barrier (BBB) maintains brain homeostasis and limits the entry of toxins and pathogens into the brain. Despite its importance, little is known about the molecular mechanisms regulating the development and function of this crucial barrier. In this study we have developed methods to highly purify and gene profile endothelial cells from different tissues, and by comparing the transcriptional

Richard Daneman; Lu Zhou; Dritan Agalliu; John D. Cahoy; Amit Kaushal; Ben A. Barres

2010-01-01

215

Brain covariance selection: better individual functional connectivity models using population prior  

E-print Network

Brain covariance selection: better individual functional connectivity models using population prior.thirion@inria.fr Abstract Spontaneous brain activity, as observed in functional neuroimaging, has been shown to display reproducible structure that expresses brain architecture and car- ries markers of brain pathologies

216

Totally tubular: the mystery behind function and origin of the brain ventricular system  

E-print Network

Totally tubular: the mystery behind function and origin of the brain ventricular system Laura Anne School, 240 Longwood Ave, Boston, MA, USA A unique feature of the vertebrate brain is the ventricular by neu- roepithelium. While CSF is critical for both adult brain function and embryonic brain development

Lowery, Laura Anne

217

Brain-specific tropomyosins TMBr-1 and TMBr-3 have distinct patterns of expression during development and in adult brain.  

PubMed

In this study we report on the developmental and regional expression of two brain-specific isoforms of tropomyosin, TMBr-1 and TMBr-3, that are generated from the rat alpha-tropomyosin gene via the use of alternative promoters and alternative RNA splicing. Western blot analysis using an exon-specific peptide polyclonal antibody revealed that the two isoforms are differentially expressed in development with TMBr-3 appearing in the embryonic brain at 16 days of gestation, followed by the expression of TMBr-1 at 20 days after birth. TMBr-3 was detected in all brain regions examined, whereas TMBr-1 was detected predominantly in brain areas that derived from the prosencephalon. Immunocytochemical studies on mixed primary cultures made from rat embryonic midbrain indicate that expression of the brain-specific epitope is restricted to neurons. The developmental pattern and neuronal localization of these forms of tropomyosin suggest that these isoforms have a specialized role in the development and plasticity of the nervous system. PMID:7694294

Stamm, S; Casper, D; Lees-Miller, J P; Helfman, D M

1993-11-01

218

Brain-specific tropomyosins TMBr-1 and TMBr-3 have distinct patterns of expression during development and in adult brain.  

PubMed Central

In this study we report on the developmental and regional expression of two brain-specific isoforms of tropomyosin, TMBr-1 and TMBr-3, that are generated from the rat alpha-tropomyosin gene via the use of alternative promoters and alternative RNA splicing. Western blot analysis using an exon-specific peptide polyclonal antibody revealed that the two isoforms are differentially expressed in development with TMBr-3 appearing in the embryonic brain at 16 days of gestation, followed by the expression of TMBr-1 at 20 days after birth. TMBr-3 was detected in all brain regions examined, whereas TMBr-1 was detected predominantly in brain areas that derived from the prosencephalon. Immunocytochemical studies on mixed primary cultures made from rat embryonic midbrain indicate that expression of the brain-specific epitope is restricted to neurons. The developmental pattern and neuronal localization of these forms of tropomyosin suggest that these isoforms have a specialized role in the development and plasticity of the nervous system. Images Fig. 1 Fig. 2 Fig. 3 Fig. 4 Fig. 5 Fig. 6 PMID:7694294

Stamm, S; Casper, D; Lees-Miller, J P; Helfman, D M

1993-01-01

219

A Patient-Specific Segmentation Framework for Longitudinal MR Images of Traumatic Brain Injury  

E-print Network

A Patient-Specific Segmentation Framework for Longitudinal MR Images of Traumatic Brain Injury Bo Science, e Brain Injury Research Center, Departments of Neurosurgery and Neurology, University and disability worldwide. Robust, reproducible segmen- tations of MR images with TBI are crucial for quantitative

Utah, University of

220

Steroid receptor coactivator-1 (SRC-1) mediates the development of sex-specific brain morphology  

E-print Network

Steroid receptor coactivator-1 (SRC-1) mediates the development of sex-specific brain morphology March 1, 2000) Steroid hormone action during brain development exerts profound effects on reproductive physiology and behavior that last into adulthood. A variety of in vitro studies indicate that steroid

221

Increased serum creatine kinase BB and neuron specific enolase following head injury indicates brain damage  

Microsoft Academic Search

Summary The aim of this study was to examine whether an increase in the serum concentrations of the two brain enzymes creatine kinase BB (CK-BB) and neuron specific enolase (NSE) can be demonstrated in patiens with acute head injury and whether such an increase reflects release from damaged brain tissue. In 60 patients who had suffered minor to severe head

I. M. Skogseid; H. K. Nordby; P. Urdal; E. Paus; F. Lilleaas

1992-01-01

222

Comments on the ``Isolation, Identification and Synthesis of a Specific-behaviour-inducing Brain Peptide''  

Microsoft Academic Search

DURING the past six years a remarkable series of publications has appeared, claiming the transfer of various specific learned behaviours from animal to animal by i.p. injection of extracts made from brains of trained donors. These are cited in the latest paper1, in which Ungar and his colleagues propose an amino acid sequence for a pentadecapeptide isolated from the brains

A. Goldstein

1973-01-01

223

Whole brain functional connectivity using phase locking measures of resting state magnetoencephalography  

PubMed Central

The analysis of spontaneous functional connectivity (sFC) reveals the statistical connections between regions of the brain consistent with underlying functional communication networks within the brain. In this work, we describe the implementation of a complete all-to-all network analysis of resting state neuronal activity from magnetoencephalography (MEG). Using graph theory to define networks at the dipole level, we established functionally defined regions by k-means clustering cortical surface locations using Eigenvector centrality (EVC) scores from the all-to-all adjacency model. Permutation testing was used to estimate regions with statistically significant connections compared to empty room data, which adjusts for spatial dependencies introduced by the MEG inverse problem. In order to test this model, we performed a series of numerical simulations investigating the effects of the MEG reconstruction on connectivity estimates. We subsequently applied the approach to subject data to investigate the effectiveness of our method in obtaining whole brain networks. Our findings indicated that our model provides statistically robust estimates of functional region networks. Application of our phase locking network methodology to real data produced networks with similar connectivity to previously published findings, specifically, we found connections between contralateral areas of the arcuate fasciculus that have been previously investigated. The use of data-driven methods for neuroscientific investigations provides a new tool for researchers in identifying and characterizing whole brain functional connectivity networks. PMID:25018690

Schmidt, Benjamin T.; Ghuman, Avniel S.; Huppert, Theodore J.

2014-01-01

224

Sleep restriction impairs blood-brain barrier function.  

PubMed

The blood-brain barrier (BBB) is a large regulatory and exchange interface between the brain and peripheral circulation. We propose that changes of the BBB contribute to many pathophysiological processes in the brain of subjects with chronic sleep restriction (CSR). To achieve CSR that mimics a common pattern of human sleep loss, we quantified a new procedure of sleep disruption in mice by a week of consecutive sleep recording. We then tested the hypothesis that CSR compromises microvascular function. CSR not only diminished endothelial and inducible nitric oxide synthase, endothelin1, and glucose transporter expression in cerebral microvessels of the BBB, but it also decreased 2-deoxy-glucose uptake by the brain. The expression of several tight junction proteins also was decreased, whereas the level of cyclooxygenase-2 increased. This coincided with an increase of paracellular permeability of the BBB to the small tracers sodium fluorescein and biotin. CSR for 6 d was sufficient to impair BBB structure and function, although the increase of paracellular permeability returned to baseline after 24 h of recovery sleep. This merits attention not only in neuroscience research but also in public health policy and clinical practice. PMID:25355222

He, Junyun; Hsuchou, Hung; He, Yi; Kastin, Abba J; Wang, Yuping; Pan, Weihong

2014-10-29

225

Recruiting specialized macrophages across the borders to restore brain functions.  

PubMed

Although is well accepted that the central nervous system has an immune privilege protected by the blood-brain barrier (BBB) and maintained by the glia, it is also known that in homeostatic conditions, peripheral immune cells are able to penetrate to the deepest regions of brain without altering the structural integrity of the BBB. Nearly all neurological diseases, including degenerative, autoimmune or infectious ones, compromising brain functions, develop with a common pattern of inflammation in which macrophages and microglia activation have been regarded often as the "bad guys." However, recognizing the huge heterogeneity of macrophage populations and also the different expression properties of microglia, there is increasing evidence of alternative conditions in which these cells, if primed and addressed in the correct direction, could be essential for reparative and regenerative functions. The main proposal of this review is to integrate studies about macrophage's biology at the brain borders where the ultimate challenge is to penetrate through the BBB and contribute to change or even stop the course of disease. Thanks to the efforts made in the last century, this special wall is currently recognized as a highly regulated cooperative structure, in which their components form neurovascular units. This new scenario prompted us to review the precise cross-talk between the mind and body modes of immune response. PMID:25228859

Corraliza, Inés

2014-01-01

226

A Network Analysis Approach to fMRI Condition-Specific Functional Connectivity  

E-print Network

In this work we focus on examination and comparison of whole-brain functional connectivity patterns measured with fMRI across experimental conditions. Direct examination and comparison of condition-specific matrices is challenging due to the large number of elements in a connectivity matrix. We present a framework that uses network analysis to describe condition-specific functional connectivity. Treating the brain as a complex system in terms of a network, we extract the most relevant connectivity information by partitioning each network into clusters representing functionally connected brain regions. Extracted clusters are used as features for predicting experimental condition in a new data set. The approach is illustrated on fMRI data examining functional connectivity patterns during processing of abstract and concrete concepts. Topological (brain regions) and functional (level of connectivity and information flow) systematic differences in the ROI-based functional networks were identified across participants for concrete and abstract concepts. These differences were sufficient for classification of previously unseen connectivity matrices as abstract or concrete based on training data derived from other people.

Svetlana V. Shinkareva; Vladimir Gudkov; Jing Wang

2010-08-03

227

Resting-state functional brain connectivity: lessons from functional near-infrared spectroscopy.  

PubMed

Resting-state functional near-infrared spectroscopy (R-fNIRS) is an active area of interest and is currently attracting considerable attention as a new imaging tool for the study of resting-state brain function. Using variations in hemodynamic concentration signals, R-fNIRS measures the brain's low-frequency spontaneous neural activity, combining the advantages of portability, low-cost, high temporal sampling rate and less physical burden to participants. The temporal synchronization of spontaneous neuronal activity in anatomically separated regions is referred to as resting-state functional connectivity (RSFC). In the past several years, an increasing body of R-fNIRS RSFC studies has led to many important findings about functional integration among local or whole-brain regions by measuring inter-regional temporal synchronization. Here, we summarize recent advances made in the R-fNIRS RSFC methodologies, from the detection of RSFC (e.g., seed-based correlation analysis, independent component analysis, whole-brain correlation analysis, and graph-theoretical topological analysis), to the assessment of RSFC performance (e.g., reliability, repeatability, and validity), to the application of RSFC in studying normal development and brain disorders. The literature reviewed here suggests that RSFC analyses based on R-fNIRS data are valid and reliable for the study of brain function in healthy and diseased populations, thus providing a promising imaging tool for cognitive science and clinics. PMID:24022325

Niu, Haijing; He, Yong

2014-04-01

228

Transcranial brain stimulation to promote functional recovery after stroke  

PubMed Central

Purpose of review Noninvasive brain stimulation (NIBS) is increasingly used to enhance the recovery of function after stroke. The purpose of this review is to highlight and discuss some unresolved questions that need to be addressed to better understand and exploit the potential of NIBS as a therapeutic tool. Recent findings Recent meta-analyses showed that the treatment effects of NIBS in patients with stroke are rather inconsistent across studies and the evidence for therapeutic efficacy is still uncertain. This raises the question of how NIBS can be developed further to improve its therapeutic efficacy. Summary This review addressed six questions: How does NIBS facilitate the recovery of function after stroke? Which brain regions should be targeted by NIBS? Is there a particularly effective NIBS modality that should be used? Does the location of the stroke influence the therapeutic response? How often should NIBS be repeated? Is the functional state of the brain during or before NIBS relevant to therapeutic efficacy of NIBS? We argue that these questions need to be tackled to obtain sufficient mechanistic understanding of how NIBS facilitates the recovery of function. This knowledge will be critical to fully unfold the therapeutic effects of NIBS and will pave the way towards adaptive NIBS protocols, in which NIBS is tailored to the individual patient. PMID:24296641

Raffin, Estelle; Siebner, Hartwig R.

2014-01-01

229

Cellular and subcellular distribution of rat brain prolyl oligopeptidase and its association with specific neuronal neurotransmitters.  

PubMed

Prolyl oligopeptidase (POP) is a serine endopeptidase that hydrolyzes proline-containing peptides shorter than 30-mer. It has been suggested that POP is associated with cognitive functions and inositol 1,4,5-triphosphate (IP(3)) signaling. However, little is known about the distribution and physiological role of POP in the brain. We used immunohistochemistry to determine the cellular and subcellular distribution of POP in the rat brain. POP was specifically expressed in the glutamatergic pyramidal neurons of the cerebral cortex, particularly in the primary motor and somatosensory cortices, and also in the CA1 field of hippocampus. Purkinje cells of the cerebellum were also intensively immunostained for POP. Double immunofluorescence indicated that POP was present in the gamma-aminobutyric acid (GABA)ergic and cholinergic interneurons of the thalamus and cortex but not in the nigrostriatal dopaminergic neurons. POP did not colocalize with astrocytic markers in any part of the rat brain. We used postembedding immunoelectron microscopy to determine the distribution of POP at the subcellular level. POP was mainly present in neuronal cytosol and membranes, hardly at all in neuronal plasma membrane, but more extensively in intracellular membranes such as the rough endoplasmic reticulum and Golgi apparatus. Our findings point to a role for POP--evidently modifying neuropeptide levels--in excitatory and inhibitory neurotransmission in the central nervous system via glutamatergic, GABAergic, and cholinergic neurotransmission systems. Furthermore, according to our results, POP may be involved in thalamocortical neurotransmission, memory and learning functions of the hippocampal formation, and GABAergic regulation of voluntary movements. Subcellular distribution of POP points to a role in protein processing and secretion. PMID:18253937

Myöhänen, Timo T; Venäläinen, Jarkko I; Garcia-Horsman, J Arturo; Piltonen, Marjo; Männistö, Pekka T

2008-04-10

230

Three-Dimensional Simulation of Carmustine Delivery to a Patient-Specific Brain Tumor  

E-print Network

This study presents the recent development of three-dimensional patient-specific simulation of carmustine delivery to brain tumor that highlights several crucial factors affecting the delivery. The simulation utilizes the ...

Arifin, Davis Yohanes

231

Specific Binding and Characteristics of 18?-Glycyrrhetinic Acid in Rat Brain  

PubMed Central

18?-Glycyrrhetinic acid (GA) is the aglycone of glycyrrhizin that is a component of Glycyrrhiza, and has several pharmacological actions in the central nervous system. Recently, GA has been demonstrated to reach the brain by crossing the blood-brain barrier in rats after oral administration of a Glycyrrhiza-containing traditional Japanese medicine, yokukansan. These findings suggest that there are specific binding sites for GA in the brain. Here we show evidence that [3H]GA binds specifically to several brain areas by quantitative autoradiography; the density was higher in the hippocampus, moderate in the caudate putamen, nucleus accumbens, amygdala, olfactory bulb, cerebral cortex, thalamus, and mid brain, and lower in the brain stem and cerebellum. Several kinds of steroids, gap junction-blocking reagents, glutamate transporter-recognized compounds, and glutamate receptor agonists did not inhibit the [3H]GA binding. Microautoradiography showed that the [3H]GA signals in the hippocampus were distributed in small non-neuronal cells similar to astrocytes. Immunohistochemical analysis revealed that immunoreactivity of 11?-hydroxysteroid dehydrogenase type-1 (11?-HSD1), a defined molecule recognized by GA, was detected mainly in neurons, moderately in astrocytes, and very slightly in microglial cells, of the hippocampus. These results demonstrate that specific binding sites for GA exist in rat brain tissue, and suggest that the pharmacological actions of GA may be related to 11?-HSD1 in astrocytes. This finding provides important information to understand the pharmacology of GA in the brain. PMID:24752617

Mizoguchi, Kazushige; Kanno, Hitomi; Ikarashi, Yasushi; Kase, Yoshio

2014-01-01

232

Nanoparticle-Mediated Brain-Specific Drug Delivery, Imaging, and Diagnosis  

Microsoft Academic Search

Central nervous system (CNS) diseases represent the largest and fastest-growing area of unmet medical need. Nanotechnology\\u000a plays a unique instrumental role in the revolutionary development of brain-specific drug delivery, imaging, and diagnosis.\\u000a With the aid of nanoparticles of high specificity and multifunctionality, such as dendrimers and quantum dots, therapeutics,\\u000a imaging agents, and diagnostic molecules can be delivered to the brain

Hu Yang

2010-01-01

233

Alteration and Reorganization of Functional Networks: A New Perspective in Brain Injury Study  

PubMed Central

Plasticity is the mechanism underlying the brain’s potential capability to compensate injury. Recently several studies have shown how functional connections among the brain areas are severely altered by brain injury and plasticity leading to a reorganization of the networks. This new approach studies the impact of brain injury by means of alteration of functional interactions. The concept of functional connectivity refers to the statistical interdependencies between physiological time series simultaneously recorded in various areas of the brain and it could be an essential tool for brain functional studies, being its deviation from healthy reference an indicator for damage. In this article, we review studies investigating functional connectivity changes after brain injury and subsequent recovery, providing an accessible introduction to common mathematical methods to infer functional connectivity, exploring their capabilities, future perspectives, and clinical uses in brain injury studies. PMID:21960965

Castellanos, Nazareth P.; Bajo, Ricardo; Cuesta, Pablo; Villacorta-Atienza, Jose Antonio; Paul, Nuria; Garcia-Prieto, Juan; del-Pozo, Francisco; Maestu, Fernando

2011-01-01

234

Neurophysiological Architecture of Functional Magnetic Resonance Images of Human Brain  

Microsoft Academic Search

We investigated large-scale systems organization of the whole human brain using functional magnetic resonance imaging (fMRI) data acquired from healthy volunteers in a no-task or 'resting' state. Images were parcellated using a prior anatomical template, yielding regional mean time series for each of 90 regions (major cortical gyri and subcortical nuclei) in each subject. Significant pairwise func- tional connections, defined

Raymond Salvador; John Suckling; Martin R. Coleman; John D. Pickard; David Menon; Ed Bullmore

2005-01-01

235

Reduced brain resting-state network specificity in infants compared with adults  

PubMed Central

Purpose Infant resting-state networks do not exhibit the same connectivity patterns as those of young children and adults. Current theories of brain development emphasize developmental progression in regional and network specialization. We compared infant and adult functional connectivity, predicting that infants would exhibit less regional specificity and greater internetwork communication compared with adults. Patients and methods Functional magnetic resonance imaging at rest was acquired in 12 healthy, term infants and 17 adults. Resting-state networks were extracted, using independent components analysis, and the resulting components were then compared between the adult and infant groups. Results Adults exhibited stronger connectivity in the posterior cingulate cortex node of the default mode network, but infants had higher connectivity in medial prefrontal cortex/anterior cingulate cortex than adults. Adult connectivity was typically higher than infant connectivity within structures previously associated with the various networks, whereas infant connectivity was frequently higher outside of these structures. Internetwork communication was significantly higher in infants than in adults. Conclusion We interpret these findings as consistent with evidence suggesting that resting-state network development is associated with increasing spatial specificity, possibly reflecting the corresponding functional specialization of regions and their interconnections through experience. PMID:25092980

Wylie, Korey P; Rojas, Donald C; Ross, Randal G; Hunter, Sharon K; Maharajh, Keeran; Cornier, Marc-Andre; Tregellas, Jason R

2014-01-01

236

Region-Specific Protein Abundance Changes in the Brain of MPTP-induced Parkinson’s Disease Mouse Model  

SciTech Connect

Parkinson’s disease (PD) is characterized by dopaminergic neurodegeneration in the nigrostriatal region of the brain; however, the neurodegeneration extends well beyond dopaminergic neurons. To gain a better understanding of the molecular changes relevant to PD, we applied two-dimensional LC-MS/MS to comparatively analyze the proteome changes in four brain regions (striatum, cerebellum, cortex, and the rest of brain) using a MPTP-induced PD mouse model with the objective to identify nigrostriatal-specific and other region-specific protein abundance changes. The combined analyses resulted in the identification of 4,895 non-redundant proteins with at least two unique peptides per protein. The relative abundance changes in each analyzed brain region were estimated based on the spectral count information. A total of 518 proteins were observed with significant MPTP-induced changes across different brain regions. 270 of these proteins were observed with specific changes occurring either only in the striatum and/or in the rest of the brain region that contains substantia nigra, suggesting that these proteins are associated with the underlying nigrostriatal pathways. Many of the proteins that exhibit significant abundance changes were associated with dopamine signaling, mitochondrial dysfunction, the ubiquitin system, calcium signaling, the oxidative stress response, and apoptosis. A set of proteins with either consistent change across all brain regions or with changes specific to the cortex and cerebellum regions were also detected. One of the interesting proteins is ubiquitin specific protease (USP9X), a deubiquination enzyme involved in the protection of proteins from degradation and promotion of the TGF-? pathway, which exhibited altered abundances in all brain regions. Western blot validation showed similar spatial changes, suggesting that USP9X is potentially associated with neurodegeneration. Together, this study for the first time presents an overall picture of proteome changes underlying both nigrostriatal pathways and other brain regions potentially involved in MPTP-induced neurodegeneration. The observed molecular changes provide a valuable reference resource for future hypothesis-driven functional studies of PD.

Zhang, Xu; Zhou, Jianying; Chin, Mark H.; Schepmoes, Athena A.; Petyuk, Vladislav A.; Weitz, Karl K.; Petritis, Brianne O.; Monroe, Matthew E.; Camp, David G.; Wood, Stephen A.; Melega, William P.; Bigelow, Diana J.; Smith, Desmond J.; Qian, Weijun; Smith, Richard D.

2010-02-15

237

Disrupted resting-state functional architecture of the brain after 45-day simulated microgravity  

PubMed Central

Long-term spaceflight induces both physiological and psychological changes in astronauts. To understand the neural mechanisms underlying these physiological and psychological changes, it is critical to investigate the effects of microgravity on the functional architecture of the brain. In this study, we used resting-state functional MRI (rs-fMRI) to study whether the functional architecture of the brain is altered after 45 days of ?6° head-down tilt (HDT) bed rest, which is a reliable model for the simulation of microgravity. Sixteen healthy male volunteers underwent rs-fMRI scans before and after 45 days of ?6° HDT bed rest. Specifically, we used a commonly employed graph-based measure of network organization, i.e., degree centrality (DC), to perform a full-brain exploration of the regions that were influenced by simulated microgravity. We subsequently examined the functional connectivities of these regions using a seed-based resting-state functional connectivity (RSFC) analysis. We found decreased DC in two regions, the left anterior insula (aINS) and the anterior part of the middle cingulate cortex (MCC; also called the dorsal anterior cingulate cortex in many studies), in the male volunteers after 45 days of ?6° HDT bed rest. Furthermore, seed-based RSFC analyses revealed that a functional network anchored in the aINS and MCC was particularly influenced by simulated microgravity. These results provide evidence that simulated microgravity alters the resting-state functional architecture of the brains of males and suggest that the processing of salience information, which is primarily subserved by the aINS–MCC functional network, is particularly influenced by spaceflight. The current findings provide a new perspective for understanding the relationships between microgravity, cognitive function, autonomic neural function, and central neural activity. PMID:24926242

Zhou, Yuan; Wang, Yun; Rao, Li-Lin; Liang, Zhu-Yuan; Chen, Xiao-Ping; Zheng, Dang; Tan, Cheng; Tian, Zhi-Qiang; Wang, Chun-Hui; Bai, Yan-Qiang; Chen, Shan-Guang; Li, Shu

2014-01-01

238

Differential changes of metabolic brain activity and interregional functional coupling in prefronto-limbic pathways during different stress conditions: functional imaging in freely behaving rodent pups  

PubMed Central

The trumpet-tailed rat or degu (Octodon degus) is an established model to investigate the consequences of early stress on the development of emotional brain circuits and behavior. The aim of this study was to identify brain circuits, that respond to different stress conditions and to test if acute stress alters functional coupling of brain activity among prefrontal and limbic regions. Using functional imaging (2-Fluoro-deoxyglucose method) in 8-day-old male degu pups the following stress conditions were compared: (A) pups together with parents and siblings (control), (B) separation of the litter from the parents, (C) individual separation from parents and siblings, and (D) individual separation and presentation of maternal calls. Condition (B) significantly downregulated brain activity in the prefrontal cortex, hippocampus, nucleus accumbens (NAcc), and sensory areas compared to controls. Activity decrease was even more pronounced during condition (C), where, in contrast to all other regions, activity in the PAG was increased. Interestingly, brain activity in stress-associated brain regions such as the amygdala and habenula was not affected. In condition (D) maternal vocalizations “reactivated” brain activity in the cingulate and precentral medial cortex, NAcc, and striatum and in sensory areas. In contrast, reduced activity was measured in the prelimbic and infralimbic cortex (IL) and in the hippocampus and amygdala. Correlation analysis revealed complex, region- and situation-specific changes of interregional functional coupling among prefrontal and limbic brain regions during stress exposure. We show here for the first time that early life stress results in a widespread reduction of brain activity in the infant brain and changes interregional functional coupling. Moreover, maternal vocalizations can partly buffer stress-induced decrease in brain activity in some regions and evoked very different functional coupling patterns compared to the three other conditions. PMID:22590453

Bock, Jorg; Riedel, Anett; Braun, Katharina

2012-01-01

239

Differential changes of metabolic brain activity and interregional functional coupling in prefronto-limbic pathways during different stress conditions: functional imaging in freely behaving rodent pups.  

PubMed

The trumpet-tailed rat or degu (Octodon degus) is an established model to investigate the consequences of early stress on the development of emotional brain circuits and behavior. The aim of this study was to identify brain circuits, that respond to different stress conditions and to test if acute stress alters functional coupling of brain activity among prefrontal and limbic regions. Using functional imaging (2-Fluoro-deoxyglucose method) in 8-day-old male degu pups the following stress conditions were compared: (A) pups together with parents and siblings (control), (B) separation of the litter from the parents, (C) individual separation from parents and siblings, and (D) individual separation and presentation of maternal calls. Condition (B) significantly downregulated brain activity in the prefrontal cortex, hippocampus, nucleus accumbens (NAcc), and sensory areas compared to controls. Activity decrease was even more pronounced during condition (C), where, in contrast to all other regions, activity in the PAG was increased. Interestingly, brain activity in stress-associated brain regions such as the amygdala and habenula was not affected. In condition (D) maternal vocalizations "reactivated" brain activity in the cingulate and precentral medial cortex, NAcc, and striatum and in sensory areas. In contrast, reduced activity was measured in the prelimbic and infralimbic cortex (IL) and in the hippocampus and amygdala. Correlation analysis revealed complex, region- and situation-specific changes of interregional functional coupling among prefrontal and limbic brain regions during stress exposure. We show here for the first time that early life stress results in a widespread reduction of brain activity in the infant brain and changes interregional functional coupling. Moreover, maternal vocalizations can partly buffer stress-induced decrease in brain activity in some regions and evoked very different functional coupling patterns compared to the three other conditions. PMID:22590453

Bock, Jörg; Riedel, Anett; Braun, Katharina

2012-01-01

240

The effect of sleep-specific brain activity versus reduced stimulus interference on declarative memory consolidation.  

PubMed

Studies suggest that the consolidation of newly acquired memories and underlying long-term synaptic plasticity might represent a major function of sleep. In a combined repeated-measures and parallel-group sleep laboratory study (active waking versus sleep, passive waking versus sleep), we provide evidence that brief periods of daytime sleep (42.1 ± 8.9 min of non-rapid eye movement sleep) in healthy adolescents (16 years old, all female), compared with equal periods of waking, promote the consolidation of declarative memory (word-pairs) in participants with high power in the electroencephalographic sleep spindle (sigma) frequency range. This observation supports the notion that sleep-specific brain activity when reaching a critical dose, beyond a mere reduction of interference, promotes synaptic plasticity in a hippocampal-neocortical network that underlies the consolidation of declarative memory. PMID:23398120

Piosczyk, Hannah; Holz, Johannes; Feige, Bernd; Spiegelhalder, Kai; Weber, Friederike; Landmann, Nina; Kuhn, Marion; Frase, Lukas; Riemann, Dieter; Voderholzer, Ulrich; Nissen, Christoph

2013-08-01

241

Topological correlations of structural and functional networks in patients with traumatic brain injury  

PubMed Central

Despite an increasing amount of specific correlation studies between structural and functional connectivity, there is still a need for combined studies, especially in pathological conditions. Impairments of brain white matter (WM) and diffuse axonal injuries are commonly suspected to be responsible for the disconnection hypothesis in traumatic brain injury (TBI) patients. Moreover, our previous research on TBI patients shows a strong relationship between abnormalities in topological organization of brain networks and behavioral deficits. In this study, we combined task-related functional connectivity (using event-related fMRI) with structural connectivity (derived from fiber tractography using diffusion MRI data) estimates in the same participants (17 adults with TBI and 16 controls), allowing for direct comparison between graph metrics of the different imaging modalities. Connectivity matrices were computed covering the switching motor network, which includes the basal ganglia, anterior cingulate cortex/supplementary motor area, and anterior insula/inferior frontal gyrus. The edges constituting this network consisted of the partial correlations between the fMRI time series from each node of the switching motor network. The interregional anatomical connections between the switching-related areas were determined using the fiber tractography results. We found that graph metrics and hubs obtained showed no agreement in both groups. The topological properties of brain functional networks could not be solely accounted for by the properties of the underlying structural networks. However, combining complementary information from both imaging modalities could improve accuracy in prediction of switching performance. Direct comparison between functional task-related and anatomical structural connectivity, presented here for the first time in TBI patients, links two powerful approaches to map the patterns of brain connectivity that may underlie behavioral deficits in brain-injured patients. PMID:24204337

Caeyenberghs, Karen; Leemans, Alexander; Leunissen, Inge; Michiels, Karla; Swinnen, Stephan P.

2013-01-01

242

Brain function in epilepsy: midbrain, medullary, and cerebellar interaction with the rostral forebrain.  

PubMed Central

Against the background previous findings in epileptic patients, in whom electroencephalographic recordings were obtained from numerous deep and surface brain sites during seizures, rhesus monkeys with electrodes implanted into specific brain sites were used to demonstrate anatomical connections by evoked potential techniques and to serve as models of experimental epilepsy. In the animals, many monosynaptic connections were revealed between forebrain sites consistently involved in seizures in patients and more caudal brain sites subserving functions of sensory perception, eye movement, synaptic chemical transmission, and motor coordination. Further, the participation of these interrelated sites during seizures was demonstrated. The findings provide an anatomical-physiological explanation for many of the clinical phenomena observed in epileptic patients and a rationale for the use of cerebellar stimulation as a treatment. PMID:827602

Heath, R G

1976-01-01

243

Multifaceted Genomic Risk for Brain Function in Schizophrenia  

PubMed Central

Recently, deriving candidate endophenotypes from brain imaging data has become a valuable approach to study genetic influences on schizophrenia (SZ), whose pathophysiology remains unclear. In this work we utilized a multivariate approach, parallel independent component analysis, to identify genomic risk components associated with brain function abnormalities in SZ. 5157 candidate single nucleotide polymorphisms (SNPs) were derived from genome-wide array based on their possible connections with SZ and further investigated for their associations with brain activations captured with functional magnetic resonance imaging (fMRI) during a sensorimotor task. Using data from 92 SZ patients and 116 healthy controls, we detected a significant correlation (r= 0.29; p= 2.41×10?5) between one fMRI component and one SNP component, both of which significantly differentiated patients from controls. The fMRI component mainly consisted of precentral and postcentral gyri, the major activated regions in the motor task. On average, higher activation in these regions was observed in participants with higher loadings of the linked SNP component, predominantly contributed to by 253 SNPs. 138 identified SNPs were from known coding regions of 100 unique genes. 31 identified SNPs did not differ between groups, but moderately correlated with some other group-discriminating SNPs, indicating interactions among alleles contributing towards elevated SZ susceptibility. The genes associated with the identified SNPs participated in four neurotransmitter pathways: GABA receptor signaling, dopamine receptor signaling, neuregulin signaling and glutamate receptor signaling. In summary, our work provides further evidence for the complexity of genomic risk to the functional brain abnormality in SZ and suggests a pathological role of interactions between SNPs, genes and multiple neurotransmitter pathways. PMID:22440650

Chen, Jiayu; Calhoun, Vince D.; Pearlson, Godfrey D.; Ehrlich, Stefan; Turner, Jessica A.; Ho, Beng-Choon; Wassink, Thomas H.; Michael, Andrew M; Liu, Jingyu

2012-01-01

244

Differences in Brain Function and Changes with Intervention in Children with Poor Spelling and Reading Abilities  

PubMed Central

Previous fMRI studies in English-speaking samples suggested that specific interventions may alter brain function in language-relevant networks in children with reading and spelling difficulties, but this research strongly focused on reading impaired individuals. Only few studies so far investigated characteristics of brain activation associated with poor spelling ability and whether a specific spelling intervention may also be associated with distinct changes in brain activity patterns. We here investigated such effects of a morpheme-based spelling intervention on brain function in 20 children with comparatively poor spelling and reading abilities using repeated fMRI. Relative to 10 matched controls, children with comparatively poor spelling and reading abilities showed increased activation in frontal medial and right hemispheric regions and decreased activation in left occipito-temporal regions prior to the intervention, during processing of a lexical decision task. After five weeks of intervention, spelling and reading comprehension significantly improved in the training group, along with increased activation in the left temporal, parahippocampal and hippocampal regions. Conversely, the waiting group showed increases in right posterior regions. Our findings could indicate an increased left temporal activation associated with the recollection of the new learnt morpheme-based strategy related to successful training. PMID:22693600

Gebauer, Daniela; Fink, Andreas; Kargl, Reinhard; Reishofer, Gernot; Koschutnig, Karl; Purgstaller, Christian; Fazekas, Franz; Enzinger, Christian

2012-01-01

245

TE-dependent spatial and spectral specificity of functional connectivity.  

PubMed

Previous studies suggest that spontaneous fluctuations in the resting-state fMRI (RS-fMRI) signal may reflect fluctuations in transverse relaxation time (T(2)(*)) rather than spin density (S(0)). However, such S(0) and T(2)(*) features have not been well characterized. In this study, spatial and spectral characteristics of functional connectivity on sensorimotor, default-mode, dorsal attention, and primary visual systems were examined using a multiple gradient-echo sequence at 3T. In the spatial domain, we found broad, local correlations at short echo times (TE ? 14 ms) due to dominant S(0) contribution, whereas long-range connections mediated by T(2)(*) became explicit at TEs longer than 22 ms. In the frequency domain, compared with the flat spectrum of S(0), spectral power of the T(2)(*)-weighted signal elevated significantly with increasing TE, particularly in the frequency ranges of 0.008-0.023 Hz and 0.037-0.043 Hz. Using the S(0) spectrum as a reference, we propose two indices to measure spectral signal change (SSC) and spectral contrast-to-noise ratio (SCNR), respectively, for quantifying the RS-fMRI signal. These indices demonstrated TE dependency of connectivity-related fluctuation strength, resembling functional contrasts in activation-based fMRI. These findings further confirm that large-scale functional circuit connectivity based on BOLD contrast may be constrained within specific frequency ranges in every brain network, and the spectral features of S(0) and T(2)(*) could be valuable for interpreting and quantifying RS-fMRI data. PMID:22119650

Wu, Changwei W; Gu, Hong; Zou, Qihong; Lu, Hanbing; Stein, Elliot A; Yang, Yihong

2012-02-15

246

Functional transcranial brain imaging by optical-resolution photoacoustic microscopy  

NASA Astrophysics Data System (ADS)

Optical-resolution photoacoustic microscopy (OR-PAM) is applied to functional brain imaging in living mice. A near-diffraction-limited bright-field optical illumination is employed to achieve micrometer lateral resolution, and a dual-wavelength measurement is utilized to extract the blood oxygenation information. The variation in hemoglobin oxygen saturation (sO2) along vascular branching has been imaged in a precapillary arteriolar tree and a postcapillary venular tree, respectively. To the best of our knowledge, this is the first report on in vivo volumetric imaging of brain microvascular morphology and oxygenation down to single capillaries through intact mouse skulls. It is anticipated that: (i) chronic imaging enabled by this minimally invasive procedure will advance the study of cortical plasticity and neurological diseases; (ii) revealing the neuroactivity-dependent changes in hemoglobin concentration and oxygenation will facilitate the understanding of neurovascular coupling at the capillary level; and (iii) combining functional OR-PAM and high-resolution blood flowmetry will have the potential to explore cellular pathways of brain energy metabolism.

Hu, Song; Maslov, Konstantin; Tsytsarev, Vassiliy; Wang, Lihong V.

2009-07-01

247

Can structure predict function in the human brain?  

PubMed

Over the past decade, scientific interest in the properties of large-scale spontaneous neural dynamics has intensified. Concurrently, novel technologies have been developed for characterizing the connective anatomy of intra-regional circuits and inter-regional fiber pathways. It will soon be possible to build computational models that incorporate these newly detailed structural network measurements to make predictions of neural dynamics at multiple scales. Here, we review the practicality and the value of these efforts, while at the same time considering in which cases and to what extent structure does determine neural function. Studies of the healthy brain, of neural development, and of pathology all yield examples of direct correspondences between structural linkage and dynamical correlation. Theoretical arguments further support the notion that brain network topology and spatial embedding should strongly influence network dynamics. Although future models will need to be tested more quantitatively and against a wider range of empirical neurodynamic features, our present large-scale models can already predict the macroscopic pattern of dynamic correlation across the brain. We conclude that as neuroscience grapples with datasets of increasing completeness and complexity, and attempts to relate the structural and functional architectures discovered at different neural scales, the value of computational modeling will continue to grow. PMID:20116438

Honey, Christopher J; Thivierge, Jean-Philippe; Sporns, Olaf

2010-09-01

248

Kappa-opioid receptor signaling and brain reward function  

PubMed Central

The dynorphin-like peptides have profound effects on the state of the brain reward system and human and animal behavior. The dynorphin-like peptides affect locomotor activity, food intake, sexual behavior, anxiety-like behavior, and drug intake. Stimulation of kappa-opioid receptors, the endogenous receptor for the dynorphin-like peptides, inhibits dopamine release in the striatum (nucleus accumbens and caudate putamen) and induces a negative mood state in humans and animals. The administration of drugs of abuse increases the release of dopamine in the striatum and mediates the concomitant release of dynorphin-like peptides in this brain region. The reviewed studies suggest that chronic drug intake leads to an upregulation of the brain dynorphin system in the striatum and in particular in the dorsal part of the striatum/caudate putamen. This might inhibit drug-induced dopamine release and provide protection against the neurotoxic effects of high dopamine levels. After the discontinuation of chronic drug intake these neuroadaptations remain unopposed which has been suggested to contribute to the negative emotional state associated with drug withdrawal and increased drug intake. Kappa-opioid receptor agonists have also been shown to inhibit calcium channels. Calcium channel inhibitors have antidepressant-like effects and inhibit the release of norepinephrine. This might explain that in some studies kappa-opioid receptor agonists attenuate nicotine and opioid withdrawal symptomatology. A better understanding of the role of dynorphins in the regulation of brain reward function might contribute to the development of novel treatments for mood disorders and other disorders that stem from a dysregulation of the brain reward system. PMID:19804796

Bruijnzeel, Adrie W.

2009-01-01

249

Scientists Probe Immune System's Role in Brain Function and Neurological Disease  

E-print Network

Scientists Probe Immune System's Role in Brain Function and Neurological Disease Bridget M. Kuehn E in normal brain development and in the healthy adult brain. Studies also suggest that per- turbations of these roles may under- lie some neurological diseases. Contrary to dogma that the blood- brain barrier

Boulanger, Lisa

250

2 Towards the study of functional brain development in depression: An Interactive 3 Specialization approach  

E-print Network

U N C O R R E C T E D P R O O F 1 Review 2 Towards the study of functional brain development Brain 21 Brain development 22 Interactive Specialization 23 Preschool depression 24 Pediatric depression synthesizing established models 29of depression and normative brain development may help to overcome them. More

251

Brain-specific deletion of neuropathy target esterase/swisscheese results in neurodegeneration  

PubMed Central

Neuropathy target esterase (NTE) is a neuronal membrane protein originally identified for its property to be modified by organo-phosphates (OPs), which in humans cause neuropathy characterized by axonal degeneration. Drosophila mutants for the homolog gene of NTE, swisscheese (sws), indicated a possible involvement of sws in the regulation of axon-glial cell interaction during glial wrapping. However, the role of NTE/sws in mammalian brain pathophysiology remains unknown. To investigate NTE function in vivo, we used the cre/loxP site-specific recombination strategy to generate mice with a specific deletion of NTE in neuronal tissues. Here we show that loss of NTE leads to prominent neuronal pathology in the hippocampus and thalamus and also defects in the cerebellum. Absence of NTE resulted in disruption of the endoplasmic reticulum, vacuolation of nerve cell bodies, and abnormal reticular aggregates. Thus, these results identify a physiological role for NTE in the nervous system and indicate that a loss-of-function mechanism may contribute to neurodegenerative diseases characterized by vacuolation and neuronal loss. PMID:15051870

Akassoglou, Katerina; Malester, Brian; Xu, Jixiang; Tessarollo, Lino; Rosenbluth, Jack; Chao, Moses V.

2004-01-01

252

The effects of methylphenidate on whole brain intrinsic functional connectivity.  

PubMed

Methylphenidate (MPH) is an indirect dopaminergic and noradrenergic agonist that is used to treat attention deficit hyperactivity disorder and that has shown therapeutic potential in neuropsychiatric diseases such as depression, dementia, and Parkinson's disease. While effects of MPH on task-induced brain activation have been investigated, little is known about how MPH influences the resting brain. To investigate the effects of 40 mg of oral MPH on intrinsic functional connectivity, we used resting state fMRI in 54 healthy male subjects in a double-blind, randomized, placebo-controlled study. Functional connectivity analysis employing ICA revealed seven resting state networks (RSN) of interest. Connectivity strength between the dorsal attention network and the thalamus was increased after MPH intake. Other RSN located in association cortex areas, such as the left and right frontoparietal networks and the executive control network, showed MPH-induced connectivity increase to sensory-motor and visual cortex regions and connectivity decrease to cortical and subcortical components of cortico-striato-thalamo-cortical circuits (CST). RSN located in sensory-motor cortex areas showed the opposite pattern with MPH-induced connectivity increase to CST components and connectivity decrease to sensory-motor and visual cortex regions. Our results provide evidence that MPH does not only alter intrinsic connectivity between brain areas involved in sustained attention, but that it also induces significant changes in the cortico-cortical and cortico-subcortical connectivity of many other cognitive and sensory-motor RSN. Hum Brain Mapp 35:5379-5388, 2014. © 2014 Wiley Periodicals, Inc. PMID:24862742

Mueller, Sophia; Costa, Anna; Keeser, Daniel; Pogarell, Oliver; Berman, Albert; Coates, Ute; Reiser, Maximilian F; Riedel, Michael; Möller, Hans-Jürgen; Ettinger, Ulrich; Meindl, Thomas

2014-11-01

253

Sleep-disordered breathing: effects on brain structure and function  

PubMed Central

Sleep-disordered breathing is accompanied by neural injury that affects a wide range of physiological systems which include processes for sensing chemoreception and airflow, driving respiratory musculature, timing circuitry for coordination of breathing patterning, and integration of blood pressure mechanisms with respiration. The damage also occurs in regions mediating emotion and mood, as well as areas regulating memory and cognitive functioning, and appears in structures that serve significant glycemic control processes. The injured structures include brain areas involved in hormone release and action of major neurotransmitters, including those playing a role in depression. The injury is reflected in a range of structural magnetic resonance procedures, and also appears as functional distortions of evoked activity in brain areas mediating vital autonomic and breathing functions. The damage is preferentially unilateral, and includes axonal projections; the asymmetry of the injury poses unique concerns for sympathetic discharge and potential consequences for arrhythmia. Sleep-disordered breathing should be viewed as a condition that includes central nervous system injury and impaired function; the processes underlying injury remain unclear. PMID:23643610

Harper, Ronald M.; Kumar, Rajesh; Ogren, Jennifer A.; Macey, Paul M.

2013-01-01

254

Functional interactions between intrinsic brain activity and behavior.  

PubMed

The brain continuously maintains a remarkably high level of intrinsic activity. This activity is non-stationary and its dynamics reveal highly structured patterns across several spatial scales, from fine-grained functional architecture in sensory cortices to large-scale networks. The mechanistic function of this activity is only poorly understood. The central goal of the current review is to provide an integrated summary of recent studies on structure, dynamics and behavioral consequences of spontaneous brain activity. In light of these empirical observations we propose that the structure of ongoing activity and its itinerant nature can be understood as an indispensible memory system modeling the statistical structure of the world. We review the dynamic properties of ongoing activity, and how they are malleable over short to long temporal scales that permit adapting over a range of short- to long-term cognitive challenges. We conclude by reviewing how the functional significance of ongoing activity manifests in its impact on human action, perception, and higher cognitive function. PMID:23643921

Sadaghiani, Sepideh; Kleinschmidt, Andreas

2013-10-15

255

Effects of severing the corpus callosum on coherent electrical and hemodynamic interhemispheric oscillations intrinsic to functional brain networks.  

E-print Network

??Large scale functional brain networks, defined by synchronized spontaneous oscillations between spatially distinct anatomical regions, are essential to brain function and have been implicated in… (more)

Magnuson, Matthew Evan

2013-01-01

256

Autism-specific maternal autoantibodies recognize critical proteins in developing brain  

E-print Network

Autism-specific maternal autoantibodies recognize critical proteins in developing brain D-Picciotto2,3,4 , IN Pessah2,3,7 and J Van de Water1,2,3 Autism spectrum disorders (ASDs of maternal autoantibody-related (MAR) autism. Exclusive reactivity to specific antigen combinations was noted

Cai, Long

257

PROTEIN III, A NEURON-SPECIFIC PHOSPHOPROTEIN: VARIANT FORMS FOUND IN HUMAN BRAIN  

EPA Science Inventory

Recent work in the laboratory has shown the presence of many neuron-specific phosphoproteins in the mammalian nervous system. Two of these proteins, Protein III and Synapsin I, are specifically associated with synaptic vesicles in neurons throughout the brain. Protein III consist...

258

Region-specific expression of Dickkopf-like1 in the adult brain. Abbreviated title: Dkkl1 in the adult brain.  

PubMed

In the adult, the dickkopf family member Dickkopf-like1 (Dkkl1) has been described as a testicular protein involved in the regulation of spermatocyte apoptosis. However, microarray studies additionally suggested that Dkkl1 regulation is involved in various tumors including high grade gliomas. Since investigations of Dkkl1 in the adult central nervous system are lacking, we analyzed Dkkl1 expression in the adult mouse brain and found a region specific expression pattern with a profoundly high cortical expression. Analysis of transgenic mice in which the lacZ gene was inserted into the Dkkl1 locus further pointed to NeuN-positive neurons as the main source of Dkkl1 in the normal adult brain. In Dkkl1(-/-) mutant mice, gross brain morphology as well as hippocampal and cortical lamination appeared normal. Similarly, neuronal density in cortical layer V was not altered. Thus, Dkkl1 may not be essential for normal brain organization, but could exert import functions during pathological conditions such as tumorigenesis and cancer progression. PMID:23295900

Sibbe, Mirjam; Jarowyj, Joël

2013-02-22

259

Functional design specification: NASA form 1510  

NASA Technical Reports Server (NTRS)

The 1510 worksheet used to calculate approved facility project cost estimates is explained. Topics covered include data base considerations, program structure, relationship of the 1510 form to the 1509 form, and functions which the application must perform: WHATIF, TENENTER, TENTYPE, and data base utilities. A sample NASA form 1510 printout and a 1510 data dictionary are presented in the appendices along with the cost adjustment table, the floppy disk index, and methods for generating the calculated values (TENCALC) and for calculating cost adjustment (CONSTADJ). Storage requirements are given.

1979-01-01

260

Brain region-specific altered expression and association of mitochondria-related genes in autism  

PubMed Central

Background Mitochondrial dysfunction (MtD) has been observed in approximately five percent of children with autism spectrum disorders (ASD). MtD could impair highly energy-dependent processes such as neurodevelopment, thereby contributing to autism. Most of the previous studies of MtD in autism have been restricted to the biomarkers of energy metabolism, while most of the genetic studies have been based on mutations in the mitochondrial DNA (mtDNA). Despite the mtDNA, most of the proteins essential for mitochondrial replication and function are encoded by the genomic DNA; so far, there have been very few studies of those genes. Therefore, we carried out a detailed study involving gene expression and genetic association studies of genes related to diverse mitochondrial functions. Methods For gene expression analysis, postmortem brain tissues (anterior cingulate gyrus (ACG), motor cortex (MC) and thalamus (THL)) from autism patients (n=8) and controls (n=10) were obtained from the Autism Tissue Program (Princeton, NJ, USA). Quantitative real-time PCR arrays were used to quantify the expression of 84 genes related to diverse functions of mitochondria, including biogenesis, transport, translocation and apoptosis. We used the delta delta Ct (??Ct) method for quantification of gene expression. DNA samples from 841 Caucasian and 188 Japanese families were used in the association study of genes selected from the gene expression analysis. FBAT was used to examine genetic association with autism. Results Several genes showed brain region-specific expression alterations in autism patients compared to controls. Metaxin 2 (MTX2), neurofilament, light polypeptide (NEFL) and solute carrier family 25, member 27 (SLC25A27) showed consistently reduced expression in the ACG, MC and THL of autism patients. NEFL (P = 0.038; Z-score 2.066) and SLC25A27 (P = 0.046; Z-score 1.990) showed genetic association with autism in Caucasian and Japanese samples, respectively. The expression of DNAJC19, DNM1L, LRPPRC, SLC25A12, SLC25A14, SLC25A24 and TOMM20 were reduced in at least two of the brain regions of autism patients. Conclusions Our study, though preliminary, brings to light some new genes associated with MtD in autism. If MtD is detected in early stages, treatment strategies aimed at reducing its impact may be adopted. PMID:23116158

2012-01-01

261

Brain contains inhibiting factors specific to the large T-antigen gene  

Microsoft Academic Search

SV40 large T-antigen (LTa) gene-induced immortalized rat dopamine-producing nerve cells (1RB3AN27), which produce LTa protein and divide in vitro, do not divide and do not produce LTa protein when transplanted into striatum of adult rats. This suggests the presence of LTa gene-inhibiting factors in brain. Here we report that rat brain soluble fraction (SF) contains factors which specifically inhibit LTa

Edward D Clarkson; Francisco G La Rosa; Judith Edwards-Prasad; Sanjay Kumar; Arun Kumar; William Cole; Curt R Freed; Kedar N Prasad

1998-01-01

262

Frequency Specificity of Regional Homogeneity in the Resting-State Human Brain  

PubMed Central

Resting state-fMRI studies have found that the inter-areal correlations in cortical networks concentrate within ultra-low frequencies (0.01–0.04 Hz) while long-distance connections within subcortical networks distribute over a wider frequency range (0.01–0.14 Hz). However, the frequency characteristics of regional homogeneity (ReHo) in different areas are still unclear. To examine the ReHo properties in different frequency bands, a data-driven method, Empirical Mode Decomposition (EMD), was adopted to decompose the time series of each voxel into several components with distinct frequency bands. ReHo values in each of the components were then calculated. Our results showed that ReHo in cortical areas were higher and more frequency-dependent than those in the subcortical regions. BOLD oscillations of 0.02–0.04 Hz mainly contributed to the cortical ReHo, whereas the ReHo in limbic areas involved a wider frequency range and were dominated by higher-frequency BOLD oscillations (>0.08 Hz). The frequency characteristics of ReHo are distinct between different parts of the striatum, with the frequency band of 0.04–0.1 Hz contributing the most to ReHo in caudate nucleus, and oscillations lower than 0.02 Hz contributing more to ReHo in putamen. The distinct frequency-specific ReHo properties of different brain areas may arise from the assorted cytoarchitecture or synaptic types in these areas. Our work may advance the understanding of the neural-physiological basis of local BOLD activities and the functional specificity of different brain regions. PMID:24466256

Song, Xiaopeng; Zhang, Yi; Liu, Yijun

2014-01-01

263

Developmental changes in category-specific brain responses to numbers and letters in a working memory task.  

PubMed

Neuroimaging studies have identified a common network of brain regions involving the prefrontal and parietal cortices across a variety of working memory (WM) tasks. However, previous studies have also reported category-specific dissociations of activation within this network. In this study, we investigated the development of category-specific activation in a WM task with digits, letters, and faces. Eight-year-old children and adults performed a 2-back WM task while their brain activity was measured using functional magnetic resonance imaging (fMRI). Overall, children were significantly slower and less accurate than adults on all three WM conditions (digits, letters, and faces); however, within each age group, behavioral performance across the three conditions was very similar. FMRI results revealed category-specific activation in adults but not children in the intraparietal sulcus for the digit condition. Likewise, during the letter condition, category-specific activation was observed in adults but not children in the left occipital-temporal cortex. In contrast, children and adults showed highly similar brain-activity patterns in the lateral fusiform gyri when solving the 2-back WM task with face stimuli. Our results suggest that 8-year-old children do not yet engage the typical brain regions that have been associated with abstract or semantic processing of numerical symbols and letters when these processes are task-irrelevant and the primary task is demanding. Nevertheless, brain activity in letter-responsive areas predicted children's spelling performance underscoring the relationship between abstract processing of letters and linguistic abilities. Lastly, behavioral performance on the WM task was predictive of math and language abilities highlighting the connection between WM and other cognitive abilities in development. PMID:19027079

Libertus, Melissa E; Brannon, Elizabeth M; Pelphrey, Kevin A

2009-02-15

264

Distinct Functions of Glial and Neuronal Dystroglycan in the Developing and Adult Mouse Brain  

PubMed Central

SUMMARY Cobblestone (type II) lissencephaly and mental retardation are characteristic features of a subset of congenital muscular dystrophies that include Walker-Warburg Syndrome, Muscle-Eye-Brain disease, and Fukuyama-type congenital muscular dystrophy. Although the majority of clinical cases are genetically undefined, several causative genes have been identified that encode known or putative glycosyltransferases in the biosynthetic pathway of dystroglycan. Here we test the effects of brain-specific deletion of dystroglycan, and show distinct functions for neuronal and glial dystroglycan. Deletion of dystroglycan in the whole brain produced glial/neuronal heterotopia resembling the cerebral cortex malformation in cobblestone lissencephaly. In wild-type mice, dystroglycan stabilizes the basement membrane of the glia limitans, thereby supporting the cortical infrastructure necessary for neuronal migration. This function depends on extracellular dystroglycan interactions, since the cerebral cortex developed normally in transgenic mice that lack the dystroglycan intracellular domain. Also, forebrain histogenesis was preserved in mice with neuron-specific deletion of dystroglycan, but hippocampal long-term potentiation was blunted, as is also the case in the Largemyd mouse, in which dystroglycan glycosylation is disrupted. Our findings provide genetic evidence that neuronal dystroglycan plays a role in synaptic plasticity and that glial dystroglycan is involved in forebrain development. Differences in dystroglycan glycosylation in distinct cell types of the CNS may therefore contribute to the diversity of dystroglycan function in the CNS, as well as to the broad clinical spectrum of type II lissencephalies. PMID:20980614

Satz, Jakob S.; Ostendorf, Adam P.; Hou, Shangwei; Turner, Amy; Kusano, Hajime; Lee, Jane C.; Turk, Rolf; Nguyen, Huy; Ross-Barta, Susan E.; Westra, Steve; Hoshi, Toshinori; Moore, Steven A.; Campbell, Kevin P.

2010-01-01

265

Resolving anatomical and functional structure in human brain organization: identifying mesoscale organization in weighted network representations.  

PubMed

Human brain anatomy and function display a combination of modular and hierarchical organization, suggesting the importance of both cohesive structures and variable resolutions in the facilitation of healthy cognitive processes. However, tools to simultaneously probe these features of brain architecture require further development. We propose and apply a set of methods to extract cohesive structures in network representations of brain connectivity using multi-resolution techniques. We employ a combination of soft thresholding, windowed thresholding, and resolution in community detection, that enable us to identify and isolate structures associated with different weights. One such mesoscale structure is bipartivity, which quantifies the extent to which the brain is divided into two partitions with high connectivity between partitions and low connectivity within partitions. A second, complementary mesoscale structure is modularity, which quantifies the extent to which the brain is divided into multiple communities with strong connectivity within each community and weak connectivity between communities. Our methods lead to multi-resolution curves of these network diagnostics over a range of spatial, geometric, and structural scales. For statistical comparison, we contrast our results with those obtained for several benchmark null models. Our work demonstrates that multi-resolution diagnostic curves capture complex organizational profiles in weighted graphs. We apply these methods to the identification of resolution-specific characteristics of healthy weighted graph architecture and altered connectivity profiles in psychiatric disease. PMID:25275860

Lohse, Christian; Bassett, Danielle S; Lim, Kelvin O; Carlson, Jean M

2014-10-01

266

Resolving Anatomical and Functional Structure in Human Brain Organization: Identifying Mesoscale Organization in Weighted Network Representations  

PubMed Central

Human brain anatomy and function display a combination of modular and hierarchical organization, suggesting the importance of both cohesive structures and variable resolutions in the facilitation of healthy cognitive processes. However, tools to simultaneously probe these features of brain architecture require further development. We propose and apply a set of methods to extract cohesive structures in network representations of brain connectivity using multi-resolution techniques. We employ a combination of soft thresholding, windowed thresholding, and resolution in community detection, that enable us to identify and isolate structures associated with different weights. One such mesoscale structure is bipartivity, which quantifies the extent to which the brain is divided into two partitions with high connectivity between partitions and low connectivity within partitions. A second, complementary mesoscale structure is modularity, which quantifies the extent to which the brain is divided into multiple communities with strong connectivity within each community and weak connectivity between communities. Our methods lead to multi-resolution curves of these network diagnostics over a range of spatial, geometric, and structural scales. For statistical comparison, we contrast our results with those obtained for several benchmark null models. Our work demonstrates that multi-resolution diagnostic curves capture complex organizational profiles in weighted graphs. We apply these methods to the identification of resolution-specific characteristics of healthy weighted graph architecture and altered connectivity profiles in psychiatric disease. PMID:25275860

Lohse, Christian; Bassett, Danielle S.; Lim, Kelvin O.; Carlson, Jean M.

2014-01-01

267

Behavioral relevance of the dynamics of the functional brain connectome.  

PubMed

Abstract While many previous studies assumed the functional connectivity (FC) between brain regions to be stationary, recent studies have demonstrated that FC dynamically varies across time. However, two challenges have limited the interpretability of dynamic FC information. First, a principled framework for selecting the temporal extent of the window used to examine the dynamics is lacking and this has resulted in ad-hoc selections of window lengths and subsequent divergent results. Second, it is unclear whether there is any behavioral relevance to the dynamics of the functional connectome in addition to that obtained from conventional static FC (SFC). In this work, we address these challenges by first proposing a principled framework for selecting the extent of the temporal windows in a dynamic and data-driven fashion based on statistical tests of the stationarity of time series. Further, we propose a method involving three levels of clustering-across space, time, and subjects-which allow for group-level inferences of the dynamics. Next, using a large resting-state functional magnetic resonance imaging and behavioral dataset from the Human Connectome Project, we demonstrate that metrics derived from dynamic FC can explain more than twice the variance in 75 behaviors across different domains (alertness, cognition, emotion, and personality traits) as compared with SFC in healthy individuals. Further, we found that individuals with brain networks exhibiting greater dynamics performed more favorably in behavioral tasks. This indicates that the ease with which brain regions engage or disengage may provide potential biomarkers for disorders involving altered neural circuitry. PMID:25163490

Jia, Hao; Hu, Xiaoping; Deshpande, Gopikrishna

2014-11-01

268

Mitochondrial activity and brain functions during cortical depolarization  

NASA Astrophysics Data System (ADS)

Cortical depolarization (CD) of the cerebral cortex could be developed under various pathophysiological conditions. In animal models, CD was recorded under partial or complete ischemia as well as when cortical spreading depression (SD) was induced externally or by internal stimulus. The development of CD in patients and the changes in various metabolic parameters, during CD, was rarely reported. Brain metabolic, hemodynamic, ionic and electrical responses to the CD event are dependent upon the O2 balance in the tissue. When the O2 balance is negative (i.e. ischemia), the CD process will be developed due to mitochondrial dysfunction, lack of energy and the inhibition of Na+-K+-ATPase. In contradiction, when oxygen is available (i.e. normoxia) the development of CD after induction of SD will accelerate mitochondrial respiration for retaining ionic homeostasis and normal brain functions. We used the multiparametric monitoring approach that enable real time monitoring of mitochondrial NADH redox state, microcirculatory blood flow and oxygenation, extracellular K+, Ca2+, H+ levels, DC steady potential and electrocorticogram (ECoG). This monitoring approach, provide a unique tool that has a significant value in analyzing the pathophysiology of the brain when SD developed under normoxia, ischemia, or hypoxia. We applied the same monitoring approach to patients suffered from severe head injury or exposed to neurosurgical procedures.

Mayevsky, Avraham; Sonn, Judith

2008-12-01

269

Individual Variability in Functional Connectivity Architecture of the Human Brain  

PubMed Central

Summary The fact that people think or behave differently from one another is rooted in individual differences in brain anatomy and connectivity. Here we used repeated-measurement resting-state functional MRI to explore inter-subject variability in connectivity. Individual differences in functional connectivity were heterogeneous across the cortex, with significantly higher variability in heteromodal association cortex and lower variability in unimodal cortices. Inter-subject variability in connectivity was significantly correlated with the degree of evolutionary cortical expansion, suggesting a potential evolutionary root of functional variability. The connectivity variability was also related to variability in sulcal depth but not cortical thickness, positively correlated with the degree of long-range connectivity but negatively correlated with local connectivity. A meta-analysis further revealed that regions predicting individual differences in cognitive domains are predominantly located in regions of high connectivity variability. Our findings have potential implications for understanding brain evolution and development, guiding intervention, and interpreting statistical maps in neuroimaging. PMID:23395382

Mueller, Sophia; Wang, Danhong; Fox, Michael D.; Thomas Yeo, B. T.; Sepulcre, Jorge; Sabuncu, Mert R.; Shafee, Rebecca; Lu, Jie; Liu, Hesheng

2013-01-01

270

cAMP-specific phosphodiesterases expression in Alzheimer's disease brains  

Microsoft Academic Search

Cyclic nucleotide signaling controls a wide variety of cellular functions. Phosphodiesterases (PDEs) regulate the intracellular levels of cAMP and cGMP, thus playing an important role in signal transduction. It has been observed that PDE4 inhibition is important for the regulation of cAMP levels in most cells involved in inflammatory processes. It has been hypothesized that inflammation is a primary process

S. Pérez-Torres; G. Mengod

2003-01-01

271

Effects of alcohol intake on brain structure and function in non-alcohol-dependent drinkers  

Microsoft Academic Search

About 85% of the adult population in the Netherlands regularly drinks alcohol. Chronic excessive alcohol intake in alcohol-dependent individuals is known to have damaging effects on brain structure and function. Relatives of alcohol-dependent individuals display differences in brain function that are similar to those found in alcoholics, even if they have never been drinking alcohol. This suggests that brain damage

Eveline Astrid de Bruin

2005-01-01

272

Performance on an episodic encoding task yields further insight into functional brain development  

E-print Network

Performance on an episodic encoding task yields further insight into functional brain development August 2006 To further characterize changes in functional brain development that are associated in the direction predicted by the endpoint analysis. We conclude that the patterns of brain activation associated

273

Hubs of brain functional networks are radically reorganized in comatose patients  

E-print Network

Hubs of brain functional networks are radically reorganized in comatose patients S. Achard , C Human brain networks have topological properties in common with many other complex systems, prompting the question: what aspects of brain network organization are critical for distinctive functional properties

Boyer, Edmond

274

Predicting Brain States from fMRI Data: Incremental Functional Principal Component  

E-print Network

Predicting Brain States from fMRI Data: Incremental Functional Principal Component Regression S@science.uva.nl Abstract We propose a method for reconstruction of human brain states directly from func- tionalMRI data to the domain of stochastic functional measurements, facilitating evaluation of brain responses

Smeulders, Arnold

275

Predictive Modeling of fMRI Brain States using Functional Canonical Correlation Analysis  

E-print Network

Predictive Modeling of fMRI Brain States using Functional Canonical Correlation Analysis S Abstract. We present a novel method for predictive modeling of human brain states from functional for prediction of naturalistic stimuli from unknown fMRI data shows that the method nds highly predictive brain

Smeulders, Arnold

276

New Approaches for Exploring Anatomical and Functional Connectivity in the Human Brain  

E-print Network

REVIEWS New Approaches for Exploring Anatomical and Functional Connectivity in the Human Brain in the primate brain is based on the complementary principles of modular and distributed information processing. The former emphasizes the specialization of functions within different brain areas. The latter emphasizes

Penny, Will

277

An independent component analysis based tool for exploring functional connections in the brain  

NASA Astrophysics Data System (ADS)

This work introduces a MATLAB-based tool developed for investigating functional connectivity in the brain. Independent component analysis (ICA) is used as a measure of voxel similarity which allows the user to find and view statistically independent maps of correlated voxels. These maps of correlated voxel activity may indicate functionally connected regions. Specialized clustering and feature extraction techniques have been designed to find and characterize clusters of activated voxels, which allows comparison of the spatial maps of correlation across subjects. This method is also used to compare the ICA generated images to fMRI images showing statistically significant activations generated by Statistical Parametric Mapping (SPM). The capability of querying specific coordinates in the brain supports integration and comparison with other data modalities such as Cortical Stimulation Mapping and Single Unit Recordings.

Rolfe, S. M.; Finney, L.; Tungaraza, R. F.; Guan, J.; Shapiro, L. G.; Brinkley, J. F.; Poliakov, A.; Kleinhans, N.; Alyward, E.

2009-02-01

278

Changes in brain functional network connectivity after stroke.  

PubMed

Studies have shown that functional network connection models can be used to study brain network changes in patients with schizophrenia. In this study, we inferred that these models could also be used to explore functional network connectivity changes in stroke patients. We used independent component analysis to find the motor areas of stroke patients, which is a novel way to determine these areas. In this study, we collected functional magnetic resonance imaging datasets from healthy controls and right-handed stroke patients following their first ever stroke. Using independent component analysis, six spatially independent components highly correlated to the experimental paradigm were extracted. Then, the functional network connectivity of both patients and controls was established to observe the differences between them. The results showed that there were 11 connections in the model in the stroke patients, while there were only four connections in the healthy controls. Further analysis found that some damaged connections may be compensated for by new indirect connections or circuits produced after stroke. These connections may have a direct correlation with the degree of stroke rehabilitation. Our findings suggest that functional network connectivity in stroke patients is more complex than that in hea-lthy controls, and that there is a compensation loop in the functional network following stroke. This implies that functional network reorganization plays a very important role in the process of rehabilitation after stroke. PMID:25206743

Li, Wei; Li, Yapeng; Zhu, Wenzhen; Chen, Xi

2014-01-01

279

Nuclear lamins in the brain--new insights into function and regulation  

PubMed Central

The nuclear lamina is an intermediate filament meshwork composed largely of four nuclear lamins—lamins A and C (A-type lamins) and lamins B1 and B2 (B-type lamins). Located immediately adjacent to the inner nuclear membrane, the nuclear lamina provides a structural scaffolding for the cell nucleus. It also interacts with both nuclear membrane proteins and the chromatin and is thought to participate in many important functions within the cell nucleus. Defects in A-type lamins cause cardiomyopathy, muscular dystrophy, peripheral neuropathy, lipodystrophy, and progeroid disorders. In contrast, the only bona fide link between the B-type lamins and human disease is a rare demyelinating disease of the central nervous system—adult-onset autosomal-dominant leukoencephalopathy, caused by a duplication of the gene for lamin B1. However, this leukoencephalopathy is not the only association between the brain and B-type nuclear lamins. Studies of conventional and tissue-specific knockout mice have demonstrated that B-type lamins play essential roles in neuronal migration in the developing brain and in neuronal survival. The importance of A-type lamin expression in the brain is unclear, but it is intriguing that the adult brain preferentially expresses lamin C rather than lamin A, very likely due to microRNA-mediated removal of prelamin A transcripts. Here, we review recent studies on nuclear lamins, focusing on the function and regulation of the nuclear lamins in the central nervous system. PMID:23065386

Jung, Hea-Jin; Lee, John M.; Yang, Shao H.; Young, Stephen G.; Fong, Loren G.

2012-01-01

280

Adaptation of the communicative brain to post-lingual deafness. Evidence from functional imaging  

E-print Network

implantation offer a unique model of brain adaptation during sensory deprivation and recovery. Functional contributed to the exploration and better understanding of sensory deprivation, especially illuminating the effect of deafness on brain adaptation. Sensory deprivation leads to modifications in relative

281

Impact of Low-Level Thyroid Hormone Disruption Induced by Propylthiouracil on Brain Development and Function.*  

EPA Science Inventory

The critical role of thyroid hormone (TH) in brain development is well established, severe deficiencies leading to significant neurological dysfunction. Much less information is available on more modest perturbations of TH on brain function. The present study induced varying degr...

282

Functional Genomics of Brain Aging and Alzheimer’s Disease: Focus on Selective Neuronal Vulnerability  

E-print Network

to account for the phenomenon of SNV. Functional genomic analyses, through unbiased whole genome expression studies, could lead to new insights into a complex process such as SNV. Genomic data generated using both human brain tissue and brains from animal...

Wang, Xinkun; Michaelis, Mary L.; Michaelis, Elias K.

2010-10-21

283

Brain tissue- and region-specific abnormalities on volumetric MRI scans in 21 patients with Bardet-Biedl syndrome (BBS)  

PubMed Central

Background Bardet-Biedl syndrome (BBS) is a heterogeneous human disorder inherited in an autosomal recessive pattern, and characterized by the primary findings of obesity, polydactyly, hypogonadism, and learning and behavioural problems. BBS mouse models have a neuroanatomical phenotype consisting of third and lateral ventriculomegaly, thinning of the cerebral cortex, and reduction in the size of the corpus striatum and hippocampus. These abnormalities raise the question of whether humans with BBS have a characteristic morphologic brain phenotype. Further, although behavioral, developmental, neurological and motor defects have been noted in patients with BBS, to date, there are limited reports of brain findings in BBS. The present study represents the largest systematic evaluation for the presence of structural brain malformations and/or progressive changes, which may contribute to these functional problems. Methods A case-control study of 21 patients, most aged 13-35 years, except for 2 patients aged 4 and 8 years, who were diagnosed with BBS by clinical criteria and genetic analysis of known BBS genes, and were evaluated by qualitative and volumetric brain MRI scans. Healthy controls were matched 3:1 by age, sex and race. Statistical analysis was performed using SAS language with SAS STAT procedures. Results All 21 patients with BBS were found to have statistically significant region- and tissue-specific patterns of brain abnormalities. There was 1) normal intracranial volume; 2) reduced white matter in all regions of the brain, but most in the occipital region; 3) preserved gray matter volume, with increased cerebral cortex volume in only the occipital lobe; 4) reduced gray matter in the subcortical regions of the brain, including the caudate, putamen and thalamus, but not in the cerebellum; and 5) increased cerebrospinal fluid volume. Conclusions There are distinct and characteristic abnormalities in tissue- and region- specific volumes of the brain in patients with BBS, which parallel the findings, described in BBS mutant mouse models. Some of these brain abnormalities may be progressive and associated with the reported neurological and behavioral problems. Further future correlation of these MRI scan findings with detailed neurologic and neuropsychological exams together with genotype data will provide better understanding of the pathophysiology of BBS. PMID:21794117

2011-01-01

284

The transcription factor PU.1 is critical for viability and function of human brain microglia.  

PubMed

Microglia are the predominant resident immune cells of the brain and can assume a range of phenotypes. They are critical for normal brain development and function but can also contribute to many disease processes. Although they are widely studied, the transcriptional control of microglial phenotype and activation requires further research. PU.1 is a key myeloid transcription factor expressed by peripheral macrophages and rodent microglia. In this article, we report the presence of PU.1 specifically in microglia of the adult human brain and we examine its functional role in primary human microglia. Using siRNA, we achieved substantial PU.1 protein knock-down in vitro. By assessing a range of characteristic microglial proteins we found decreased viability of adult human microglia with reduced PU.1 protein expression. This observation was confirmed with PU.1 antisense DNA oligonucleotides. An important function of microglia is to clear debris by phagocytosis. We assessed the impact of loss of PU.1 on microglial phagocytosis and show that PU.1 siRNA reduces the ability of adult human microglia to phagocytose amyloid-beta1-42 peptide. These results show that PU.1 controls human microglial viability and function and suggest PU.1 as a molecular target for manipulation of human microglial phenotype. PMID:23483680

Smith, Amy M; Gibbons, Hannah M; Oldfield, Robyn L; Bergin, Peter M; Mee, Edward W; Faull, Richard L M; Dragunow, Mike

2013-06-01

285

Brain images, babies, and bathwater: critiquing critiques of functional neuroimaging.  

PubMed

Since the mid-1980s, psychologists and neuroscientists have used brain imaging to test hypotheses about human thought processes and their neural instantiation. In just three decades, functional neuroimaging has been transformed from a crude clinical tool to a widely used research method for understanding the human brain and mind. Such rapidly achieved success is bound to evoke skepticism. A degree of skepticism toward new methods and ideas is both inevitable and useful in any field. It is especially valuable in a science as young as cognitive neuroscience and its even younger siblings, social and affective neuroscience. Healthy skepticism encourages us to check our assumptions, recognize the limitations of our methods, and proceed thoughtfully. Skepticism itself, however, also must be examined. In this article, I review the most commonly voiced criticisms of functional neuroimaging. In the spirit of healthy skepticism, I will critically examine these criticisms themselves. Each contains at least a kernel of truth, although I will argue that in some cases the kernel has been over extended in ways that are inaccurate or misleading. PMID:24634081

Farah, Martha J

2014-01-01

286

[The stimulating impact of light on brain cognition function].  

PubMed

Light regulates multiple non-visual circadian, neuroendocrine, and neurobehavioral functions, and conveys a strong stimulating signal for alert-ness and cognition. This review summarizes a series of neuroimaging studies investigating the brain mechanisms underlying the latter stimulating impact of light. Results of these studies are compatible with a scenario where light would first hit subcortical areas involved in arousal regulation before affecting cortical areas involved in the ongoing non-visual cognitive process, and then cognitive performance. Recent data demonstrated that the non-visual impact of light is most likely triggered via outputs from intrinsically photosensitive retinal ganglion cells (ipRGC) expressing the photopigment melanopsin, which are maximally sensitive to blue light. In addition, the stimulating impact of light is intimately related to wakefulness regulation as it changes with circadian phase and sleep pressure. Finally, markers of inter-individual difference have also been described: age, PERIOD3 genotype, and psychiatric status. This review emphasizes the importance of light for human brain cognitive function and for cognition in general. PMID:25311026

Vandewalle, Gilles

2014-10-01

287

Is Social Phobia a “Mis-Communication” Disorder? Brain Functional Connectivity during Face Perception Differs between Patients with Social Phobia and Healthy Control Subjects  

PubMed Central

Recently, a differential recruitment of brain areas throughout the distributed neural system for face perception has been found in social phobic patients as compared to healthy control subjects. These functional abnormalities in social phobic patients extend beyond emotion-related brain areas, such as the amygdala, to include cortical networks that modulate attention and process other facial features, and they are also associated with an alteration of the task-related activation/deactivation trade-off. Functional connectivity is becoming a powerful tool to examine how components of large-scale distributed neural systems are coupled together while performing a specific function. This study was designed to determine whether functional connectivity networks among brain regions within the distributed system for face perception also would differ between social phobic patients and healthy controls. Data were obtained from eight social phobic patients and seven healthy controls by using functional magnetic resonance imaging. Our findings indicated that social phobic patients and healthy controls have different patterns of functional connectivity across brain regions within both the core and the extended systems for face perception and the default mode network. To our knowledge, this is the first study that shows that functional connectivity during brain response to socially relevant stimuli differs between social phobic patients and healthy controls. These results expand our previous findings and indicate that brain functional changes in social phobic patients are not restricted to a single specific brain structure, but rather involve a mis-communication among different sensory and emotional processing brain areas. PMID:21152341

Danti, Sabrina; Ricciardi, Emiliano; Gentili, Claudio; Gobbini, Maria Ida; Pietrini, Pietro; Guazzelli, Mario

2010-01-01

288

Functional abnormalities in normally appearing athletes following mild traumatic brain injury: a functional MRI study  

Microsoft Academic Search

Memory problems are one of the most common symptoms of sport-related mild traumatic brain injury (MTBI), known as concussion.\\u000a Surprisingly, little research has examined spatial memory in concussed athletes given its importance in athletic environments.\\u000a Here, we combine functional magnetic resonance imaging (fMRI) with a virtual reality (VR) paradigm designed to investigate\\u000a the possibility of residual functional deficits in recently

Semyon M. Slobounov; K. Zhang; D. Pennell; W. Ray; B. Johnson; W. Sebastianelli

2010-01-01

289

Computational modeling of high-level cognition and brain function.  

PubMed

This article describes a computational modeling architecture, 4CAPS, which is consistent with key properties of cortical function and makes good contact with functional neuroimaging results. Like earlier cognitive models such as SOAR, ACT-R, 3CAPS, and EPIC, the proposed cognitive model is implemented in a computer simulation that predicts observable variables such as human response times and error patterns. In addition, the proposed 4CAPS model accounts for the functional decomposition of the cognitive system and predicts fMRI activation levels and their localization within specific cortical regions, by incorporating key properties of cortical function into the design of the modeling system. PMID:10524604

Just, M A; Carpenter, P A; Varma, S

1999-01-01

290

Dynamic reconfiguration of structural and functional connectivity across core neurocognitive brain networks with development  

PubMed Central

Brain structural and functional development, throughout childhood and into adulthood, underlies the maturation of increasingly sophisticated cognitive abilities. High-level attentional and cognitive control processes rely on the integrity of, and dynamic interactions between, core neurocognitive networks. The right fronto-insular cortex (rFIC) is a critical component of a salience network (SN) that mediates interactions between large-scale brain networks involved in externally-oriented attention (central executive network, CEN) and internally-oriented cognition (default mode network, DMN). How these systems reconfigure and mature with development is a critical question for cognitive neuroscience, with implications for neurodevelopmental pathologies affecting brain connectivity. Using functional and effective connectivity measures applied to fMRI data, we examine interactions within and between the SN, CEN, and DMN. We find that functional coupling between key network nodes is stronger in adults than in children, as are causal links emanating from the rFIC. Specifically, the causal influence of the rFIC on nodes of the SN and CEN was significantly greater in adults compared to children. Notably, these results were entirely replicated on an independent dataset of matched children and adults. Developmental changes in functional and effective connectivity were related to structural connectivity along these links. DTI tractography revealed increased structural integrity in adults compared to children along both within- and between-network pathways associated with the rFIC. These results suggest that structural and functional maturation of rFIC pathways is a critical component of the process by which human brain networks mature during development to support complex, flexible cognitive processes in adulthood. PMID:22171056

Uddin, Lucina Q.; Supekar, Kaustubh S.; Ryali, Srikanth; Menon, Vinod

2013-01-01

291

Dynamic reconfiguration of structural and functional connectivity across core neurocognitive brain networks with development.  

PubMed

Brain structural and functional development, throughout childhood and into adulthood, underlies the maturation of increasingly sophisticated cognitive abilities. High-level attentional and cognitive control processes rely on the integrity of, and dynamic interactions between, core neurocognitive networks. The right fronto-insular cortex (rFIC) is a critical component of a salience network (SN) that mediates interactions between large-scale brain networks involved in externally oriented attention [central executive network (CEN)] and internally oriented cognition [default mode network (DMN)]. How these systems reconfigure and mature with development is a critical question for cognitive neuroscience, with implications for neurodevelopmental pathologies affecting brain connectivity. Using functional and effective connectivity measures applied to fMRI data, we examine interactions within and between the SN, CEN, and DMN. We find that functional coupling between key network nodes is stronger in adults than in children, as are causal links emanating from the rFIC. Specifically, the causal influence of the rFIC on nodes of the SN and CEN was significantly greater in adults compared with children. Notably, these results were entirely replicated on an independent dataset of matched children and adults. Developmental changes in functional and effective connectivity were related to structural connectivity along these links. Diffusion tensor imaging tractography revealed increased structural integrity in adults compared with children along both within- and between-network pathways associated with the rFIC. These results suggest that structural and functional maturation of rFIC pathways is a critical component of the process by which human brain networks mature during development to support complex, flexible cognitive processes in adulthood. PMID:22171056

Uddin, Lucina Q; Supekar, Kaustubh S; Ryali, Srikanth; Menon, Vinod

2011-12-14

292

Zinc homeostasis and functions of zinc in the brain  

Microsoft Academic Search

The brain barrier system, i.e., the blood-brain and blood-cerebrospinal fluid barriers, is important for zinc homeostasis in the brain. Zinc is supplied to the brain via both barriers. A large portion of zinc serves as zinc metalloproteins in neurons and glial cells. Approximately 10% of the total zinc in the brain, probably ionic zinc, exists in the synaptic vesicles, and

Atsushi Takeda

2001-01-01

293

Brain imaging methods used in experimental brain research such as Positron Emission Tomography (PET) and Functional  

E-print Network

ABSTRACT Brain imaging methods used in experimental brain research such as Positron Emission of methods create statistical parametric maps (SPMs) of the brain on a voxel- basis. In our approach, they are best understood in the context of the underly- ing 3-D brain anatomy. However, despite the power

Mueller, Klaus

294

Fetal functional imaging portrays heterogeneous development of emerging human brain networks  

PubMed Central

The functional connectivity architecture of the adult human brain enables complex cognitive processes, and exhibits a remarkably complex structure shared across individuals. We are only beginning to understand its heterogeneous structure, ranging from a strongly hierarchical organization in sensorimotor areas to widely distributed networks in areas such as the parieto-frontal cortex. Our study relied on the functional magnetic resonance imaging (fMRI) data of 32 fetuses with no detectable morphological abnormalities. After adapting functional magnetic resonance acquisition, motion correction, and nuisance signal reduction procedures of resting-state functional data analysis to fetuses, we extracted neural activity information for major cortical and subcortical structures. Resting fMRI networks were observed for increasing regional functional connectivity from 21st to 38th gestational weeks (GWs) with a network-based statistical inference approach. The overall connectivity network, short range, and interhemispheric connections showed sigmoid expansion curve peaking at the 26–29 GW. In contrast, long-range connections exhibited linear increase with no periods of peaking development. Region-specific increase of functional signal synchrony followed a sequence of occipital (peak: 24.8 GW), temporal (peak: 26 GW), frontal (peak: 26.4 GW), and parietal expansion (peak: 27.5 GW). We successfully adapted functional neuroimaging and image post-processing approaches to correlate macroscopical scale activations in the fetal brain with gestational age. This in vivo study reflects the fact that the mid-fetal period hosts events that cause the architecture of the brain circuitry to mature, which presumably manifests in increasing strength of intra- and interhemispheric functional macro connectivity. PMID:25374531

Jakab, Andras; Schwartz, Ernst; Kasprian, Gregor; Gruber, Gerlinde M.; Prayer, Daniela; Schopf, Veronika; Langs, Georg

2014-01-01

295

Accurately assessing the risk of schizophrenia conferred by rare copy-number variation affecting genes with brain function.  

PubMed

Investigators have linked rare copy number variation (CNVs) to neuropsychiatric diseases, such as schizophrenia. One hypothesis is that CNV events cause disease by affecting genes with specific brain functions. Under these circumstances, we expect that CNV events in cases should impact brain-function genes more frequently than those events in controls. Previous publications have applied "pathway" analyses to genes within neuropsychiatric case CNVs to show enrichment for brain-functions. While such analyses have been suggestive, they often have not rigorously compared the rates of CNVs impacting genes with brain function in cases to controls, and therefore do not address important confounders such as the large size of brain genes and overall differences in rates and sizes of CNVs. To demonstrate the potential impact of confounders, we genotyped rare CNV events in 2,415 unaffected controls with Affymetrix 6.0; we then applied standard pathway analyses using four sets of brain-function genes and observed an apparently highly significant enrichment for each set. The enrichment is simply driven by the large size of brain-function genes. Instead, we propose a case-control statistical test, cnv-enrichment-test, to compare the rate of CNVs impacting specific gene sets in cases versus controls. With simulations, we demonstrate that cnv-enrichment-test is robust to case-control differences in CNV size, CNV rate, and systematic differences in gene size. Finally, we apply cnv-enrichment-test to rare CNV events published by the International Schizophrenia Consortium (ISC). This approach reveals nominal evidence of case-association in neuronal-activity and the learning gene sets, but not the other two examined gene sets. The neuronal-activity genes have been associated in a separate set of schizophrenia cases and controls; however, testing in independent samples is necessary to definitively confirm this association. Our method is implemented in the PLINK software package. PMID:20838587

Raychaudhuri, Soumya; Korn, Joshua M; McCarroll, Steven A; Altshuler, David; Sklar, Pamela; Purcell, Shaun; Daly, Mark J

2010-09-01

296

Accurately Assessing the Risk of Schizophrenia Conferred by Rare Copy-Number Variation Affecting Genes with Brain Function  

PubMed Central

Investigators have linked rare copy number variation (CNVs) to neuropsychiatric diseases, such as schizophrenia. One hypothesis is that CNV events cause disease by affecting genes with specific brain functions. Under these circumstances, we expect that CNV events in cases should impact brain-function genes more frequently than those events in controls. Previous publications have applied “pathway” analyses to genes within neuropsychiatric case CNVs to show enrichment for brain-functions. While such analyses have been suggestive, they often have not rigorously compared the rates of CNVs impacting genes with brain function in cases to controls, and therefore do not address important confounders such as the large size of brain genes and overall differences in rates and sizes of CNVs. To demonstrate the potential impact of confounders, we genotyped rare CNV events in 2,415 unaffected controls with Affymetrix 6.0; we then applied standard pathway analyses using four sets of brain-function genes and observed an apparently highly significant enrichment for each set. The enrichment is simply driven by the large size of brain-function genes. Instead, we propose a case-control statistical test, cnv-enrichment-test, to compare the rate of CNVs impacting specific gene sets in cases versus controls. With simulations, we demonstrate that cnv-enrichment-test is robust to case-control differences in CNV size, CNV rate, and systematic differences in gene size. Finally, we apply cnv-enrichment-test to rare CNV events published by the International Schizophrenia Consortium (ISC). This approach reveals nominal evidence of case-association in neuronal-activity and the learning gene sets, but not the other two examined gene sets. The neuronal-activity genes have been associated in a separate set of schizophrenia cases and controls; however, testing in independent samples is necessary to definitively confirm this association. Our method is implemented in the PLINK software package. PMID:20838587

Raychaudhuri, Soumya; Korn, Joshua M.; McCarroll, Steven A.; Altshuler, David; Sklar, Pamela; Purcell, Shaun; Daly, Mark J.

2010-01-01

297

Correlation between the Effects of Acupuncture at Taichong (LR3) and Functional Brain Areas: A Resting-State Functional Magnetic Resonance Imaging Study Using True versus Sham Acupuncture  

PubMed Central

Functional magnetic resonance imaging (fMRI) has been shown to detect the specificity of acupuncture points, as proved by numerous studies. In this study, resting-state fMRI was used to observe brain areas activated by acupuncture at the Taichong (LR3) acupoint. A total of 15 healthy subjects received brain resting-state fMRI before acupuncture and after sham and true acupuncture, respectively, at LR3. Image data processing was performed using Data Processing Assistant for Resting-State fMRI and REST software. The combination of amplitude of low-frequency fluctuation (ALFF) and regional homogeneity (ReHo) was used to analyze the changes in brain function during sham and true acupuncture. Acupuncture at LR3 can specifically activate or deactivate brain areas related to vision, movement, sensation, emotion, and analgesia. The specific alterations in the anterior cingulate gyrus, thalamus, and cerebellar posterior lobe have a crucial effect and provide a valuable reference. Sham acupuncture has a certain effect on psychological processes and does not affect brain areas related to function. PMID:24963329

Qu, Shanshan; Zhang, Jiping; Chen, Junqi; Zhang, Shaoqun; Li, Zhipeng; Chen, Jiarong; Ouyang, Huailiang; Huang, Yong; Tang, Chunzhi

2014-01-01

298

Recursive Cluster Elimination Based Support Vector Machine for Disease State Prediction Using Resting State Functional and Effective Brain Connectivity  

PubMed Central

Background Brain state classification has been accomplished using features such as voxel intensities, derived from functional magnetic resonance imaging (fMRI) data, as inputs to efficient classifiers such as support vector machines (SVM) and is based on the spatial localization model of brain function. With the advent of the connectionist model of brain function, features from brain networks may provide increased discriminatory power for brain state classification. Methodology/Principal Findings In this study, we introduce a novel framework where in both functional connectivity (FC) based on instantaneous temporal correlation and effective connectivity (EC) based on causal influence in brain networks are used as features in an SVM classifier. In order to derive those features, we adopt a novel approach recently introduced by us called correlation-purged Granger causality (CPGC) in order to obtain both FC and EC from fMRI data simultaneously without the instantaneous correlation contaminating Granger causality. In addition, statistical learning is accelerated and performance accuracy is enhanced by combining recursive cluster elimination (RCE) algorithm with the SVM classifier. We demonstrate the efficacy of the CPGC-based RCE-SVM approach using a specific instance of brain state classification exemplified by disease state prediction. Accordingly, we show that this approach is capable of predicting with 90.3% accuracy whether any given human subject was prenatally exposed to cocaine or not, even when no significant behavioral differences were found between exposed and healthy subjects. Conclusions/Significance The framework adopted in this work is quite general in nature with prenatal cocaine exposure being only an illustrative example of the power of this approach. In any brain state classification approach using neuroimaging data, including the directional connectivity information may prove to be a performance enhancer. When brain state classification is used for disease state prediction, our approach may aid the clinicians in performing more accurate diagnosis of diseases in situations where in non-neuroimaging biomarkers may be unable to perform differential diagnosis with certainty. PMID:21151556

Deshpande, Gopikrishna; Li, Zhihao; Santhanam, Priya; Coles, Claire D.; Lynch, Mary Ellen; Hamann, Stephan; Hu, Xiaoping

2010-01-01

299

Functional brain networks and cognitive deficits in Parkinson's disease.  

PubMed

Graph-theoretical analyses of functional networks obtained with resting-state functional magnetic resonance imaging (fMRI) have recently proven to be a useful approach for the study of the substrates underlying cognitive deficits in different diseases. We used this technique to investigate whether cognitive deficits in Parkinson's disease (PD) are associated with changes in global and local network measures. Thirty-six healthy controls (HC) and 66 PD patients matched for age, sex, and education were classified as having mild cognitive impairment (MCI) or not based on performance in the three mainly affected cognitive domains in PD: attention/executive, visuospatial/visuoperceptual (VS/VP), and declarative memory. Resting-state fMRI and graph theory analyses were used to evaluate network measures. We have found that patients with MCI had connectivity reductions predominantly affecting long-range connections as well as increased local interconnectedness manifested as higher measures of clustering, small-worldness, and modularity. The latter measures also tended to correlate negatively with cognitive performance in VS/VP and memory functions. Hub structure was also reorganized: normal hubs displayed reduced centrality and degree in MCI PD patients. Our study indicates that the topological properties of brain networks are changed in PD patients with cognitive deficits. Our findings provide novel data regarding the functional substrate of cognitive impairment in PD, which may prove to have value as a prognostic marker. PMID:24639411

Baggio, Hugo-Cesar; Sala-Llonch, Roser; Segura, Bàrbara; Marti, Maria-José; Valldeoriola, Francesc; Compta, Yaroslau; Tolosa, Eduardo; Junqué, Carme

2014-09-01

300

Evidence for a gender-specific protective role of innate immune receptors in a model of perinatal brain injury.  

PubMed

Hypoxia-ischemia is a common cause of neurological impairments in newborns, but little is known about how neuroinflammation contributes to the long-term outcome after a perinatal brain injury. In this study, we investigated the role of the fractalkine receptor chemokine CX3C motif receptor 1 (CX3CR1) and of toll-like receptor (TLR) signaling after a neonatal hypoxic-ischemic brain injury. Mice deficient in the TLR adaptor proteins Toll/interleukin-1 receptor-domain-containing adaptor protein inducing interferon ? (TRIF) or myeloid differentiation factor-88 (MyD88) and CX3CR1 knock-out (KO) mice were subjected to hypoxia-ischemia at postnatal day 3. In situ hybridization was used to evaluate the expression of TLRs during brain development and after hypoxic-ischemic insults. Behavioral deficits, hippocampal damage, reactive microgliosis, and subplate injury were compared among the groups. Although MyD88 KO mice exhibited no differences from wild-type animals in long-term structural and functional outcomes, TRIF KO mice presented a worse outcome, as evidenced by increased hippocampal CA3 atrophy in males and by the development of learning and motor deficits in females. CX3CR1-deficient female mice showed a marked increase in brain damage and long-lasting learning deficits, whereas CX3CR1 KO male animals did not exhibit more brain injury than wild-type mice. These data reveal a novel, gender-specific protective role of TRIF and CX3CR1 signaling in a mouse model of neonatal hypoxic-ischemic brain injury. These findings suggest that future studies seeking immunomodulatory therapies for preterm infants should consider gender as a critical variable and should be cautious not to abrogate the protective role of neuroinflammation. PMID:23843525

Pimentel-Coelho, Pedro M; Michaud, Jean-Philippe; Rivest, Serge

2013-07-10

301

Compelling Evidence that Exposure Therapy for PTSD Normalizes Brain Function.  

PubMed

Functional magnetic resonance imaging (fMRI) is helping us better understand the neurologic pathways involved in posttraumatic stress disorder (PTSD). We previously reported that military service members with PTSD after deployment to Iraq or Afghanistan demonstrated significant improvement, or normalization, in the fMRI-measured activation of the amygdala, prefrontal cortex and anterior cingulate gyrus following exposure therapy for PTSD. However, our original study design did not include repeat scans of control participants, rendering it difficult to discern how much of the observed normalization in brain activity is attributable to treatment, rather than merely a practice effect. Using the same Affective Stroop task paradigm, we now report on a larger sample of PTSD-positive combat veterans that we treated with exposure therapy, as well as a combat-exposed control group of service members who completed repeat scans at 3-4 month intervals. Findings from the treatment group are similar to our prior report. Combat controls showed no significant change on repeat scanning, indicating that the observed differences in the intervention group were in fact due to treatment. We continue to scan additional study participants, in order to determine whether virtual reality exposure therapy has a different impact on regional brain activation than other therapies for PTSD. PMID:24875691

Roy, Michael J; Costanzo, Michelle E; Blair, James R; Rizzo, Albert A

2014-01-01

302

``Frog, where are you?'' Narratives in children with specific language impairment, early focal brain injury,  

E-print Network

to investigate language development in children from 4 to 12 years of age from three experimental groups as chronological age matched typically developing children Brain and Language 88 (2004) 229­247 www``Frog, where are you?'' Narratives in children with specific language impairment, early focal

303

California Verbal Learning Test Indicators of Malingered Neurocognitive Dysfunction: Sensitivity and Specificity in Traumatic Brain Injury  

ERIC Educational Resources Information Center

The present study used well-defined traumatic brain injury (TBI) and mixed neurological (other than TBI) and psychiatric samples to examine the specificity and sensitivity to Malingered Neurocognitive Dysfunction (MND) of four individual California Verbal Learning Test (CVLT) variables and eight composite CVLT malingering indicators. Participants…

Curtis, Kelly L.; Greve, Kevin W.; Bianchini, Kevin J.; Brennan, Adrianne

2006-01-01

304

Social Stress in Hamsters: Defeat Activates Specific Neurocircuits within the Brain  

Microsoft Academic Search

During an agonistic encounter, subordinate male hamsters dis- play defensive and submissive postures and show increased secretion of glucocorticoids, whereas dominant males do not. To determine whether specific neuronal pathways are activated during the behavioral and neuroendocrine responses of subor- dinate males, expression of c-fos mRNA within the brains of subordinate males was compared with the pattern in dominant males

S. Kollack-Walker; S. J. Watson; H. Akil

1997-01-01

305

Circadian Misalignment, Reward-Related Brain Function, and Adolescent Alcohol Involvement  

PubMed Central

Background Developmental changes in sleep and circadian rhythms that occur during adolescence may contribute to reward-related brain dysfunction, and consequently increase the risk of alcohol use disorders (AUDs). Methods This review (a) describes marked changes in circadian rhythms, reward-related behavior and brain function, and alcohol involvement that occur during adolescence, (b) offers evidence that these parallel developmental changes are associated, and (c) posits a conceptual model by which misalignment between sleep-wake timing and endogenous circadian timing may increase the risk of adolescent AUDs by altering reward-related brain function. Results The timing of sleep shifts later throughout adolescence, in part due to developmental changes in endogenous circadian rhythms, which tend to become more delayed. This tendency for delayed sleep and circadian rhythms is at odds with early school start times during secondary education, leading to misalignment between many adolescents’ sleep-wake schedules and their internal circadian timing. Circadian misalignment is associated with increased alcohol use and other risk-taking behaviors, as well as sleep loss and sleep disturbance. Growing evidence indicates that circadian rhythms modulate the reward system, suggesting that circadian misalignment may impact adolescent alcohol involvement by altering reward-related brain function. Neurocognitive function is also subject to sleep and circadian influence, and thus circadian misalignment may also impair inhibitory control and other cognitive processes relevant to alcohol use. Specifically, circadian misalignment may further exacerbate the cortical-subcortical imbalance within the reward circuit, an imbalance thought to explain increased risk-taking and sensation-seeking during adolescence. Adolescent alcohol use is highly contexualized, however, and thus studies testing this model will also need to consider factors that may influence both circadian misalignment and alcohol use. Conclusions This review highlights growing evidence supporting a path by which circadian misalignment may disrupt reward mechanisms, which may in turn accelerate the transition from alcohol use to AUDs in vulnerable adolescents. PMID:23360461

Hasler, Brant P.; Clark, Duncan B.

2013-01-01

306

The temporal structures and functional significance of scale-free brain activity.  

PubMed

Scale-free dynamics, with a power spectrum following P proportional to f(-beta), are an intrinsic feature of many complex processes in nature. In neural systems, scale-free activity is often neglected in electrophysiological research. Here, we investigate scale-free dynamics in human brain and show that it contains extensive nested frequencies, with the phase of lower frequencies modulating the amplitude of higher frequencies in an upward progression across the frequency spectrum. The functional significance of scale-free brain activity is indicated by task performance modulation and regional variation, with beta being larger in default network and visual cortex and smaller in hippocampus and cerebellum. The precise patterns of nested frequencies in the brain differ from other scale-free dynamics in nature, such as earth seismic waves and stock market fluctuations, suggesting system-specific generative mechanisms. Our findings reveal robust temporal structures and behavioral significance of scale-free brain activity and should motivate future study on its physiological mechanisms and cognitive implications. PMID:20471349

He, Biyu J; Zempel, John M; Snyder, Abraham Z; Raichle, Marcus E

2010-05-13

307

In vivo visuotopic brain mapping with manganese-enhanced MRI and resting-state functional connectivity MRI.  

PubMed

The rodents are an increasingly important model for understanding the mechanisms of development, plasticity, functional specialization and disease in the visual system. However, limited tools have been available for assessing the structural and functional connectivity of the visual brain network globally, in vivo and longitudinally. There are also ongoing debates on whether functional brain connectivity directly reflects structural brain connectivity. In this study, we explored the feasibility of manganese-enhanced MRI (MEMRI) via 3 different routes of Mn(2+) administration for visuotopic brain mapping and understanding of physiological transport in normal and visually deprived adult rats. In addition, resting-state functional connectivity MRI (RSfcMRI) was performed to evaluate the intrinsic functional network and structural-functional relationships in the corresponding anatomical visual brain connections traced by MEMRI. Upon intravitreal, subcortical, and intracortical Mn(2+) injection, different topographic and layer-specific Mn enhancement patterns could be revealed in the visual cortex and subcortical visual nuclei along retinal, callosal, cortico-subcortical, transsynaptic and intracortical horizontal connections. Loss of visual input upon monocular enucleation to adult rats appeared to reduce interhemispheric polysynaptic Mn(2+) transfer but not intra- or inter-hemispheric monosynaptic Mn(2+) transport after Mn(2+) injection into visual cortex. In normal adults, both structural and functional connectivity by MEMRI and RSfcMRI was stronger interhemispherically between bilateral primary/secondary visual cortex (V1/V2) transition zones (TZ) than between V1/V2 TZ and other cortical nuclei. Intrahemispherically, structural and functional connectivity was stronger between visual cortex and subcortical visual nuclei than between visual cortex and other subcortical nuclei. The current results demonstrated the sensitivity of MEMRI and RSfcMRI for assessing the neuroarchitecture, neurophysiology and structural-functional relationships of the visual brains in vivo. These may possess great potentials for effective monitoring and understanding of the basic anatomical and functional connections in the visual system during development, plasticity, disease, pharmacological interventions and genetic modifications in future studies. PMID:24394694

Chan, Kevin C; Fan, Shu-Juan; Chan, Russell W; Cheng, Joe S; Zhou, Iris Y; Wu, Ed X

2014-04-15

308

[Organ specific water-soluble cerebral cortex proteins; possible participation in physiological functions and pathologic manifestations].  

PubMed

The spectre of active antigens in brain is studied. The presence of 3 protein and 3 glycoprotein brain specific antigens is demonstrated. The possible participation of brain specific antigens in increased antibody formation in schizophrenics, multiple sclerosis and lateral ammiotrophic sclerosis is studied. The data obtained indicate the role of brain specific antigens to autoimmunity in those patients. The possible participation of one of the specific antigens of the brain, sialoglycoprotein GP-350, in physiological processes connected with the mechanism of memory is also studied. In experiments of inbred trained rats an activation of the synthesis of GP-350 is observed. PMID:756641

Vartanian, M E; Burbaeva, G Sh; Ignatov, S A; Nazarian, K B

1978-01-01

309

Specific Benzodiazepine Receptors in Rat Brain Characterized by High-Affinity [3H]diazepam binding  

Microsoft Academic Search

[3H]Diazepam appears to bind specifically to a single, saturable, binding site located on rat brain membranes, with an affinity constant near 3 nM at pH 7.4. Specific binding constitutes more than 90% of total binding at 0 degrees and less than 10% of total binding at 37 degrees. Arrhenius plots suggest a sharp conformational change in the diazepam receptor near

Claus Braestrup; Richard F. Squires

1977-01-01

310

Brain site-specific proteome changes in aging-related dementia  

PubMed Central

This study is aimed at gaining insights into the brain site-specific proteomic senescence signature while comparing physiologically aged brains with aging-related dementia brains (for example, Alzheimer's disease (AD)). Our study of proteomic differences within the hippocampus (Hp), parietal cortex (pCx) and cerebellum (Cb) could provide conceptual insights into the molecular mechanisms involved in aging-related neurodegeneration. Using an isobaric tag for relative and absolute quantitation (iTRAQ)-based two-dimensional liquid chromatography coupled with tandem mass spectrometry (2D-LC-MS/MS) brain site-specific proteomic strategy, we identified 950 proteins in the Hp, pCx and Cb of AD brains. Of these proteins, 31 were significantly altered. Most of the differentially regulated proteins are involved in molecular transport, nervous system development, synaptic plasticity and apoptosis. Particularly, proteins such as Gelsolin (GSN), Tenascin-R (TNR) and AHNAK could potentially act as novel biomarkers of aging-related neurodegeneration. Importantly, our Ingenuity Pathway Analysis (IPA)-based network analysis further revealed ubiquitin C (UBC) as a pivotal protein to interact with diverse AD-associated pathophysiological molecular factors and suggests the reduced ubiquitin proteasome degradation system (UPS) as one of the causative factors of AD. PMID:24008896

Manavalan, Arulmani; Mishra, Manisha; Feng, Lin; Sze, Siu Kwan; Akatsu, Hiroyasu; Heese, Klaus

2013-01-01

311

Acute Stress Differentially Affects Aromatase Activity in Specific Brain Nuclei of Adult Male and Female Quail  

PubMed Central

The rapid and temporary suppression of reproductive behavior is often assumed to be an important feature of the adaptive acute stress response. However, how this suppression operates at the mechanistic level is poorly understood. The enzyme aromatase converts testosterone to estradiol in the brain to activate reproductive behavior in male Japanese quail (Coturnix japonica). The discovery of rapid and reversible modification of aromatase activity (AA) provides a potential mechanism for fast, stress-induced changes in behavior. We investigated the effects of acute stress on AA in both sexes by measuring enzyme activity in all aromatase-expressing brain nuclei before, during, and after 30 min of acute restraint stress. We show here that acute stress rapidly alters AA in the male and female brain and that these changes are specific to the brain nuclei and sex of the individual. Specifically, acute stress rapidly (5 min) increased AA in the male medial preoptic nucleus, a region controlling male reproductive behavior; in females, a similar increase was also observed, but it appeared delayed (15 min) and had smaller amplitude. In the ventromedial and tuberal hypothalamus, regions associated with female reproductive behavior, stress induced a quick and sustained decrease in AA in females, but in males, only a slight increase (ventromedial) or no change (tuberal) in AA was observed. Effects of acute stress on brain estrogen production, therefore, represent one potential way through which stress affects reproduction. PMID:21878510

Cornil, Charlotte A.; Balthazart, Jacques

2011-01-01

312

Acute stress differentially affects aromatase activity in specific brain nuclei of adult male and female quail.  

PubMed

The rapid and temporary suppression of reproductive behavior is often assumed to be an important feature of the adaptive acute stress response. However, how this suppression operates at the mechanistic level is poorly understood. The enzyme aromatase converts testosterone to estradiol in the brain to activate reproductive behavior in male Japanese quail (Coturnix japonica). The discovery of rapid and reversible modification of aromatase activity (AA) provides a potential mechanism for fast, stress-induced changes in behavior. We investigated the effects of acute stress on AA in both sexes by measuring enzyme activity in all aromatase-expressing brain nuclei before, during, and after 30 min of acute restraint stress. We show here that acute stress rapidly alters AA in the male and female brain and that these changes are specific to the brain nuclei and sex of the individual. Specifically, acute stress rapidly (5 min) increased AA in the male medial preoptic nucleus, a region controlling male reproductive behavior; in females, a similar increase was also observed, but it appeared delayed (15 min) and had smaller amplitude. In the ventromedial and tuberal hypothalamus, regions associated with female reproductive behavior, stress induced a quick and sustained decrease in AA in females, but in males, only a slight increase (ventromedial) or no change (tuberal) in AA was observed. Effects of acute stress on brain estrogen production, therefore, represent one potential way through which stress affects reproduction. PMID:21878510

Dickens, Molly J; Cornil, Charlotte A; Balthazart, Jacques

2011-11-01

313

Driving and Driven Architectures of Directed Small-World Human Brain Functional Networks  

Microsoft Academic Search

Recently, increasing attention has been focused on the investigation of the human brain connectome that describes the patterns of structural and functional connectivity networks of the human brain. Many studies of the human connectome have demonstrated that the brain network follows a small-world topology with an intrinsically cohesive modular structure and includes several network hubs in the medial parietal regions.

Chaogan Yan; Yong He

2011-01-01

314

Categories and Functional Units: An Infinite Hierarchical Model for Brain Activations  

E-print Network

Categories and Functional Units: An Infinite Hierarchical Model for Brain Activations Danial present a model that describes the structure in the responses of different brain areas to a set of stimuli encodes the relationship between brain activations and fMRI time courses. A variational inference

Golland, Polina

315

The Organization of Local and Distant Functional Connectivity in the Human Brain  

Microsoft Academic Search

Information processing in the human brain arises from both interactions between adjacent areas and from distant projections that form distributed brain systems. Here we map interactions across different spatial scales by estimating the degree of intrinsic functional connectivity for the local (?14 mm) neighborhood directly surrounding brain regions as contrasted with distant (>14 mm) interactions. The balance between local and

Jorge Sepulcre; Hesheng Liu; Tanveer Talukdar; Iñigo Martincorena; B. T. Thomas Yeo; Randy L. Buckner

2010-01-01

316

Complex brain networks: graph theoretical analysis of structural and functional systems  

Microsoft Academic Search

Recent developments in the quantitative analysis of complex networks, based largely on graph theory, have been rapidly translated to studies of brain network organization. The brain's structural and functional systems have features of complex networks — such as small-world topology, highly connected hubs and modularity — both at the whole-brain scale of human neuroimaging and at a cellular scale in

Olaf Sporns; Ed Bullmore

2009-01-01

317

Expression and function of the LIM homeodomain protein Apterous during embryonic brain development of Drosophila  

Microsoft Academic Search

We analyzed the expression and function of the LIM-homeodomain transcription factor Apterous (Ap) in embryonic brain development of Drosophila. Expression of Ap in the embryonic brain begins at early stage 12 and is subsequently found in approximately 200 protocerebral neurons and in 4 deutocerebral neurons. Brain glia do not express Ap. Most of the Ap-expressing neurons are interneurons and project

Martin C. Herzig; Stefan Thor; John B. Thomas; Heinrich Reichert; Frank Hirth

2001-01-01

318

Is 21st Century Neuroscience Too Focussed on the Rat/Mouse Model of Brain Function and Dysfunction?  

PubMed Central

Studies in the basic neurosciences are heavily reliant upon rat and mouse models. The brain is one of the most distinguishing features of the human species, but is enough being done to fully understand the evolution of the human brain and brain diversity in general? Without a clear understanding of the evolution of the nervous system we may be investing a great deal of effort into some limited specific animal models that may prove to be erroneous in terms of the overall usefulness in clinically applied research. Here we present an analysis that demonstrates that 75% of our research efforts are directed to the rat, mouse and human brain, or 0.0001% of the nervous systems on the planet. This extreme bias in research trends may provide a limited scope in the discovery of novel aspects of brain structure and function that would be of importance in understanding both the evolution of the human brain and in selecting appropriate animal models for use in clinically related research. We offer examples both from the historical and recent literature indicating the usefulness of comparative neurobiological investigation in elucidating both normal and abnormal structure and function of the brain. PMID:19127284

Manger, Paul R.; Cort, Jessica; Ebrahim, Naseem; Goodman, Adelaya; Henning, Justine; Karolia, Mohamed; Rodrigues, Stacey-Lee; Strkalj, Goran

2008-01-01

319

Imaging local brain function with emission computed tomography  

SciTech Connect

Positron emission tomography (PET) using /sup 18/F-fluorodeoxyglucose (FDG) was used to map local cerebral glucose utilization in the study of local cerebral function. This information differs fundamentally from structural assessment by means of computed tomography (CT). In normal human volunteers, the FDG scan was used to determine the cerebral metabolic response to conrolled sensory stimulation and the effects of aging. Cerebral metabolic patterns are distinctive among depressed and demented elderly patients. The FDG scan appears normal in the depressed patient, studded with multiple metabolic defects in patients with multiple infarct dementia, and in the patients with Alzheimer disease, metabolism is particularly reduced in the parietal cortex, but only slightly reduced in the caudate and thalamus. The interictal FDG scan effectively detects hypometabolic brain zones that are sites of onset for seizures in patients with partial epilepsy, even though these zones usually appear normal on CT scans. The future prospects of PET are discussed.

Kuhl, D.E.

1984-03-01

320

Working Memory Updating Function Training Influenced Brain Activity  

PubMed Central

Recent studies demonstrated that working memory could be improved by training. We recruited healthy adult participants and used adaptive running working memory training tasks with a double-blind design, combined with the event-related potentials (ERPs) approach, to explore the influence of updating function training on brain activity. Participants in the training group underwent training for 20 days. Compared with the control group, the training group's accuracy (ACC) in the two-back working memory task had no significant differences after training, but reaction time (RT) was reduced significantly. Besides, the amplitudes of N160 and P300 increased significantly whereas that of P200 decreased significantly. The results suggest that training could have improved the participants' capacity on both inhibitory and updating. PMID:24015182

Zhao, Xin; Zhou, Renlai; Fu, Li

2013-01-01

321

Warping of a computerized 3-D atlas to match brain image volumes for quantitative neuroanatomical and functional analysis  

NASA Astrophysics Data System (ADS)

We describe the implementation, experience and preliminary results obtained with a 3-D computerized brain atlas for topographical and functional analysis of brain sub-regions. A volume-of-interest (VOI) atlas was produced by manual contouring on 64 adjacent 2 mm-thick MRI slices to yield 60 brain structures in each hemisphere which could be adjusted, originally by global affine transformation or local interactive adjustments, to match individual MRI datasets. We have now added a non-linear deformation (warp) capability (Bookstein, 1989) into the procedure for fitting the atlas to the brain data. Specific target points are identified in both atlas and MRI spaces which define a continuous 3-D warp transformation that maps the atlas on to the individual brain image. The procedure was used to fit MRI brain image volumes from 16 young normal volunteers. Regional volume and positional variability were determined, the latter in such a way as to assess the extent to which previous linear models of brain anatomical variability fail to account for the true variation among normal individuals. Using a linear model for atlas deformation yielded 3-D fits of the MRI data which, when pooled across subjects and brain regions, left a residual mis-match of 6 - 7 mm as compared to the non-linear model. The results indicate a substantial component of morphometric variability is not accounted for by linear scaling. This has profound implications for applications which employ stereotactic coordinate systems which map individual brains into a common reference frame: quantitative neuroradiology, stereotactic neurosurgery and cognitive mapping of normal brain function with PET. In the latter case, the combination of a non-linear deformation algorithm would allow for accurate measurement of individual anatomic variations and the inclusion of such variations in inter-subject averaging methodologies used for cognitive mapping with PET.

Evans, Alan C.; Dai, Weiqian; Collins, D. Louis; Neelin, Peter; Marrett, Sean

1991-06-01

322

Analysis of functional pathways altered after mild traumatic brain injury.  

PubMed

Concussive injury (or mild traumatic brain injury; mTBI) can exhibit features of focal or diffuse injury patterns. We compared and contrasted the cellular and molecular responses after mild controlled cortical impact (mCCI; a focal injury) or fluid percussion injury (FPI; a diffuse injury) in rats. The rationale for this comparative analysis was to investigate the brain's response to mild diffuse versus mild focal injury to identify common molecular changes triggered by these injury modalities and to determine the functional pathways altered after injury that may provide novel targets for therapeutic intervention. Microarrays containing probes against 21,792 unique messenger RNAs (mRNAs) were used to investigate the changes in cortical mRNA expression levels at 3 and 24?h postinjury. Of the 354 mRNAs with significantly altered expression levels after mCCI, over 89% (316 mRNAs) were also contained within the mild FPI (mFPI) data set. However, mFPI initiated a more widespread molecular response, with over 2300 mRNAs differentially expressed. Bioinformatic analysis of annotated gene ontology molecular function and biological pathway terms showed a significant overrepresentation of genes belonging to inflammation, stress, and signaling categories in both data sets. We therefore examined changes in the protein levels of a panel of 23 cytokines and chemokines in cortical extracts using a Luminex-based bead immunoassay and detected significant increases in macrophage inflammatory protein (MIP)-1? (CCL3), GRO-KC (CXCL1), interleukin (IL)-1?, IL-1?, and IL-6. Immunohistochemical localization of MIP-1? and IL-1? showed marked increases at 3?h postinjury in the cortical vasculature and microglia, respectively, that were largely resolved by 24?h postinjury. Our findings demonstrate that both focal and diffuse mTBI trigger many shared pathobiological processes (e.g., inflammatory responses) that could be targeted for mechanism-based therapeutic interventions. PMID:22913729

Redell, John B; Moore, Anthony N; Grill, Raymond J; Johnson, Daniel; Zhao, Jing; Liu, Yin; Dash, Pramod K

2013-05-01

323

Sex- and brain region-specific role of cytochrome c oxidase in 1-methyl-4-phenylpyridinium-mediated astrocyte vulnerability.  

PubMed

Parkinson's disease is a neurodegenerative disorder characterized by a sex and brain region specificity, showing a higher incidence in men than in women, which is caused by cell death of mainly dopaminergic neurons in the mesencephalon. Mitochondrial toxins are often used to trigger and mimic neurodegenerative processes. Thus, systemic application of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) induces Parkinsonian symptoms, indicating a causative or consequent involvement of mitochondria. Therefore, mitochondria of neural cells may demonstrate a sex and brain region specificity with respect to structural and functional characteristics of these organelles during toxic and degenerative processes. The application of MPTP in vivo and its toxic derivative 1-methyl-4-phenylpyridinium (MPP(+) ) in vitro represent a well-accepted experimental model of Parkinson's disease. Aside from the known effects of MPP(+) on mitochondria and neural cell survivability and with respect to the supportive role of astrocytes for neuronal function, we aimed to demonstrate the involvement of cytochrome c oxidase subunit IV isoform expression in energy and reactive oxygen species production taking part in an impairment of astrocyte survival. MPP(+) caused a specific increase of COX IV-2 transcript and protein levels in male mesencephalic astrocytes, accompanied by decreased ATP and increased reactive oxygen species levels and elevated apoptotic cell death, which were more pronounced in mesencephalic than in cortical astrocytes from male than from female mice. Our data suggest that MPP(+) acts on astrocytes in a sex- and brain region-specific manner involving cytochrome c oxidase isoform expression in an impairment of energy production and elevated oxidative stress levels, which represent hallmarks of neurodegenerative diseases. PMID:21598289

Sundar Boyalla, Syama; Barbara Victor, Marion; Roemgens, André; Beyer, Cordian; Arnold, Susanne

2011-12-01

324

Oxytocin enhances brain function in children with autism  

PubMed Central

Following intranasal administration of oxytocin (OT), we measured, via functional MRI, changes in brain activity during judgments of socially (Eyes) and nonsocially (Vehicles) meaningful pictures in 17 children with high-functioning autism spectrum disorder (ASD). OT increased activity in the striatum, the middle frontal gyrus, the medial prefrontal cortex, the right orbitofrontal cortex, and the left superior temporal sulcus. In the striatum, nucleus accumbens, left posterior superior temporal sulcus, and left premotor cortex, OT increased activity during social judgments and decreased activity during nonsocial judgments. Changes in salivary OT concentrations from baseline to 30 min postadministration were positively associated with increased activity in the right amygdala and orbitofrontal cortex during social vs. nonsocial judgments. OT may thus selectively have an impact on salience and hedonic evaluations of socially meaningful stimuli in children with ASD, and thereby facilitate social attunement. These findings further the development of a neurophysiological systems-level understanding of mechanisms by which OT may enhance social functioning in children with ASD. PMID:24297883

Gordon, Ilanit; Vander Wyk, Brent C.; Bennett, Randi H.; Cordeaux, Cara; Lucas, Molly V.; Eilbott, Jeffrey A.; Zagoory-Sharon, Orna; Leckman, James F.; Feldman, Ruth; Pelphrey, Kevin A.

2013-01-01

325

Functional brain imaging studies of youth depression: A systematic review?  

PubMed Central

Background There is growing interest in understanding the neurobiology of major depressive disorder (MDD) in youth, particularly in the context of neuroimaging studies. This systematic review provides a timely comprehensive account of the available functional magnetic resonance imaging (fMRI) literature in youth MDD. Methods A literature search was conducted using PubMED, PsycINFO and Science Direct databases, to identify fMRI studies in younger and older youth with MDD, spanning 13–18 and 19–25 years of age, respectively. Results Twenty-eight studies focusing on 5 functional imaging domains were identified, namely emotion processing, cognitive control, affective cognition, reward processing and resting-state functional connectivity. Elevated activity in “extended medial network” regions including the anterior cingulate, ventromedial and orbitofrontal cortices, as well as the amygdala was most consistently implicated across these five domains. For the most part, findings in younger adolescents did not differ from those in older youth; however a general comparison of findings in both groups compared to adults indicated differences in the domains of cognitive control and affective cognition. Conclusions Youth MDD is characterized by abnormal activations in ventromedial frontal regions, the anterior cingulate and amygdala, which are broadly consistent with the implicated role of medial network regions in the pathophysiology of depression. Future longitudinal studies examining the effects of neurodevelopmental changes and pubertal maturation on brain systems implicated in youth MDD will provide a more comprehensive neurobiological model of youth depression. PMID:24455472

Kerestes, Rebecca; Davey, Christopher G.; Stephanou, Katerina; Whittle, Sarah; Harrison, Ben J.

2013-01-01

326

Neurovascular coupling: in vivo optical techniques for functional brain imaging  

PubMed Central

Optical imaging techniques reflect different biochemical processes in the brain, which is closely related with neural activity. Scientists and clinicians employ a variety of optical imaging technologies to visualize and study the relationship between neurons, glial cells and blood vessels. In this paper, we present an overview of the current optical approaches used for the in vivo imaging of neurovascular coupling events in small animal models. These techniques include 2-photon microscopy, laser speckle contrast imaging (LSCI), voltage-sensitive dye imaging (VSDi), functional photoacoustic microscopy (fPAM), functional near-infrared spectroscopy imaging (fNIRS) and multimodal imaging techniques. The basic principles of each technique are described in detail, followed by examples of current applications from cutting-edge studies of cerebral neurovascular coupling functions and metabolic. Moreover, we provide a glimpse of the possible ways in which these techniques might be translated to human studies for clinical investigations of pathophysiology and disease. In vivo optical imaging techniques continue to expand and evolve, allowing us to discover fundamental basis of neurovascular coupling roles in cerebral physiology and pathophysiology. PMID:23631798

2013-01-01

327

Brain Hyperthermia During Physiological and Pathological Conditions: Causes, Mechanisms, and Functional Implications  

Microsoft Academic Search

Although brain metabolism consumes high amounts of energy and is accompanied by intense heat production, brain temperature is usually considered a stable, tightly regulated homeostatic parameter. Current animal research, however, has shown that different forms of functional neural activation are accompanied by relatively large brain hyperthermia (2-3°C), which has an intra-brain origin; cerebral circulation plays a crucial role in dissipating

Eugene A. Kiyatkin

2004-01-01

328

Aberrant spontaneous brain activity in chronic tinnitus patients revealed by resting-state functional MRI  

PubMed Central

Objective The neural mechanisms that give rise to the phantom sound of tinnitus are poorly understood. This study aims to investigate whether aberrant spontaneous brain activity exists in chronic tinnitus patients using resting-state functional magnetic resonance imaging (fMRI) technique. Materials and methods A total of 31 patients with chronic tinnitus patients and 32 healthy age-, sex-, and education-matched healthy controls were prospectively examined. Both groups had normal hearing thresholds. We calculated the amplitude of low-frequency fluctuations (ALFFs) of fMRI signals to measure spontaneous neuronal activity and detect the relationship between fMRI information and clinical data of tinnitus. Results Compared with healthy controls, we observed significant increased ALFF within several selected regions including the right middle temporal gyrus (MTG), right superior frontal gyrus (SFG), and right angular gyrus; decreased ALFF was detected in the left cuneus, right middle occipital gyrus and bilateral thalamus. Moreover, tinnitus distress correlated positively with increased ALFF in right MTG and right SFG; tinnitus duration correlated positively with higher ALFF values in right SFG. Conclusions The present study confirms that chronic tinnitus patients have aberrant ALFF in many brain regions, which is associated with specific clinical tinnitus characteristics. ALFF disturbance in specific brain regions might be used to identify the neuro-pathophysiological mechanisms in chronic tinnitus patients. PMID:25379434

Chen, Yu-Chen; Zhang, Jian; Li, Xiao-Wei; Xia, Wenqing; Feng, Xu; Gao, Bo; Ju, Sheng-Hong; Wang, Jian; Salvi, Richard; Teng, Gao-Jun

2014-01-01

329

Cell Type Specific Analysis of Human Brain Transcriptome Data to Predict Alterations in Cellular Composition  

PubMed Central

The central nervous system (CNS) is composed of hundreds of distinct cell types, each expressing different subsets of genes from the genome. High throughput gene expression analysis of the CNS from patients and controls is a common method to screen for potentially pathological molecular mechanisms of psychiatric disease. One mechanism by which gene expression might be seen to vary across samples would be alterations in the cellular composition of the tissue. While the expressions of gene ‘markers’ for each cell type can provide certain information of cellularity, for many rare cell types markers are not well characterized. Moreover, if only small sets of markers are known, any substantial variation of a marker’s expression pattern due to experiment conditions would result in poor sensitivity and specificity. Here, our proposed method combines prior information from mice cell-specific transcriptome profiling experiments with co-expression network analysis, to select large sets of potential cell type-specific gene markers in a systematic and unbiased manner. The method is efficient and robust, and identifies sufficient markers for further cellularity analysis. We then employ the markers to analytically detect changing cellular composition in human brain. Application of our method to temporal human brain microarray data successfully detects changes in cellularity over time that roughly correspond to known epochs of human brain development. Furthermore, application of our method to human brain samples with the neurodevelopmental disorder of autism supports the interpretation that the changes in astrocytes and neurons might contribute to the disorder. PMID:25340014

Xu, Xiaoxiao; Nehorai, Arye; Dougherty, Joseph

2013-01-01

330

Chemokine Receptor CXCR7 Is a Functional Receptor for CXCL12 in Brain Endothelial Cells  

PubMed Central

The chemokine CXCL12 regulates multiple cell functions through its receptor, CXCR4. However, recent studies have shown that CXCL12 also binds a second receptor, CXCR7, to potentiate signal transduction and cell activity. In contrast to CXCL12/CXCR4, few studies have focused on the role of CXCR7 in vascular biology and its role in human brain microvascular endothelial cells (HBMECs) remains unclear. In this report, we used complementary methods, including immunocytofluorescence, Western blot, and flow cytometry analyses, to demonstrate that CXCR7 was expressed on HBMECs. We then employed short hairpin RNA (shRNA) technology to knockdown CXCR7 in HBMECs. Knockdown of CXCR7 in HBMECs resulted in significantly reduced HBMEC proliferation, tube formation, and migration, as well as adhesion to matrigel and tumor cells. Blocking CXCR7 with a specific antibody or small molecule antagonist similarly disrupted HBMEC binding to matrigel or tumor cells. We found that tumor necrosis factor (TNF)-? induced CXCR7 in a time and dose-response manner and that this increase preceded an increase in vascular cell adhesion molecule-1 (VCAM-1). Knockdown of CXCR7 resulted in suppression of VCAM-1, suggesting that the reduced binding of CXCR7-knockdown HBMECs may result from suppression of VCAM-1. Collectively, CXCR7 acted as a functional receptor for CXCL12 in brain endothelial cells. Targeting CXCR7 in tumor vasculature may provide novel opportunities for improving brain tumor therapy. PMID:25084358

Liu, Yang; Carson-Walter, Eleanor; Walter, Kevin A.

2014-01-01

331

Near-infrared spectroscopy: does it function in functional activation studies of the adult brain?  

Microsoft Academic Search

Changes in optical properties of biological tissue can be examined by near-infrared spectroscopy (NIRS). The relative transparency of tissues including the skull to near-infrared light is the prerequisite to apply the method to brain research. We describe the methodology with respect to its applicability in non-invasive functional research of the adult cortex. A summary of studies establishing the ‘typical’ response

Hellmuth Obrig; Rüdiger Wenzel; Matthias Kohl; Susanne Horst; Petra Wobst; Jens Steinbrink; Florian Thomas; Arno Villringer

2000-01-01

332

Crew interface specifications development for inflight maintenance and stowage functions  

NASA Technical Reports Server (NTRS)

Findings and data products developed during crew specification study for inflight maintenance and stowage functions are reported. From this information base, a family of data concepts to support crew inflight troubleshooting and corrective maintenance activities was developed and specified. Recommendations are made for the improvement of inflight maintenance planning, preparations and operations in future space flight programs through the establishment of an inflight maintenance organization and specific suggestions for techniques to improve the management of the inflight maintenance function.

Carl, J. G.

1974-01-01

333

Spatiotemporal and time-frequency analysis of functional near infrared spectroscopy brain signals using independent component analysis.  

PubMed

Functional near infrared spectroscopy (fNIRS) is a noninvasive method to capture brain activities according to the measurements of changes in both oxyhemoglobin and deoxyhemoglobin concentrations. However, fNIRS recordings are the hemodynamic signals that come from the latent neural sources that are spatially and temporally mixed across the brain. The purpose of this work is to extract the temporal and frequency characteristics as well as the spatial activation patterns in the brains using independent component analysis (ICA). In this study, the filtered fNIRS recordings were processed and the time-frequency and spatiotemporal domain independent components (ICs) were identified by ICA. We found that multiple task-related components can be separated by ICA in time-frequency domain, and distinct spatial patterns of brain activity can be derived from ICs that are well correlated with the specific neural events, such as finger tapping tasks. PMID:24150092

Yuan, Zhen

2013-10-01

334

Glial enriched gene expression profiling identifies novel factors regulating the proliferation of specific glial subtypes in the Drosophila brain  

PubMed Central

Glial cells constitute a large proportion of the central nervous system (CNS) and are critical for the correct development and function of the adult CNS. Recent studies have shown that specific subtypes of glia are generated through the proliferation of differentiated glial cells in both the developing invertebrate and vertebrate nervous systems. However, the factors that regulate glial proliferation in specific glial subtypes are poorly understood. To address this we have performed global gene expression analysis of Drosophila post-embryonic CNS tissue enriched in glial cells, through glial specific overexpression of either the FGF or insulin receptor. Analysis of the differentially regulated genes in these tissues shows that the expression of known glial genes is significantly increased in both cases. Conversely, the expression of neuronal genes is significantly decreased. FGF and insulin signalling drive the expression of overlapping sets of genes in glial cells that then activate proliferation. We then used these data to identify novel transcription factors that are expressed in glia in the brain. We show that two of the transcription factors identified in the glial enriched gene expression profiles, foxO and tramtrack69, have novel roles in regulating the proliferation of cortex and perineurial glia. These studies provide new insight into the genes and molecular pathways that regulate the proliferation of specific glial subtypes in the Drosophila post-embryonic brain. PMID:25217886

Avet-Rochex, Amelie; Maierbrugger, Katja T.; Bateman, Joseph M.

2014-01-01

335

A finite element model of region-specific response for mild diffuse brain injury.  

PubMed

It is well known that rotational loading is responsible for a spectrum of diffuse brain injuries spanning from concussion to diffuse axonal trauma. Many experimental studies have been performed to understand the pathological and biomechanical factors associated with diffuse brain injuries. Finite element models have also been developed to correlate experimental findings with intrinsic variables such as strain. However, a paucity of studies exist examining the combined role of the strain-time parameter. Consequently, using the principles of finite element analysis, the present study introduced the concept of sustained maximum principal strain (SMPS) criterion and explored its potential applicability to diffuse brain injury. An algorithm was developed to determine if the principal strain in a finite element of the brain exceeded a specified magnitude over a specific time interval. The anatomical and geometrical details of the rat for the two-dimensional model were obtained from published data. Using material properties from literature and iterative techniques, the model was validated under three distinct rotational loading conditions indicative of non-injury, concussion, and diffuse axonal trauma. Validation results produced a set of material properties to define the model and were deemed appropriate to examine the role of sustained strain as an indicator of the mechanics of mild diffuse brain injury at the local level. Using a separate set of histological data obtained from graded mild diffuse brain injury experimental studies in rats, different formulations of SMPS criterion were evaluated. For the hippocampus and parietal cortex regions, 4-4 SMPS criterion was found to most closely match with the pattern of histological results. This was further verified by correlating the fractional areas to the time of unconsciousness for each animal group. Although not fully conclusive, these results are valuable in the understanding of diffuse brain injury pathologies following rotational loading. PMID:20058555

Fijalkowski, Ronald J; Yoganandan, Narayan; Zhang, Jiangyue; Pintar, Frank A

2009-11-01

336

Brain natriuretic peptide predicts functional outcome in ischemic stroke  

PubMed Central

Background Elevated serum levels of brain natriuretic peptide (BNP) have been associated with cardioembolic (CE) stroke and increased post-stroke mortality. We sought to determine whether BNP levels were associated with functional outcome after ischemic stroke. Methods We measured BNP in consecutive patients aged ?18 years admitted to our Stroke Unit between 2002–2005. BNP quintiles were used for analysis. Stroke subtypes were assigned using TOAST criteria. Outcomes were measured as 6-month modified Rankin Scale score (“good outcome” = 0–2 vs. “poor”) as well as mortality. Multivariate logistic regression was used to assess association between the quintiles of BNP and outcomes. Predictive performance of BNP as compared to clinical model alone was assessed by comparing ROC curves. Results Of 569 ischemic stroke patients, 46% were female; mean age was 67.9 ± 15 years. In age- and gender-adjusted analysis, elevated BNP was associated with lower ejection fraction (p<0.0001) and left atrial dilatation (p<0.001). In multivariate analysis, elevated BNP decreased the odds of good functional outcome (OR 0.64, 95%CI 0.41–0.98) and increased the odds of death (OR 1.75, 95%CI 1.36–2.24) in these patients. Addition of BNP to multivariate models increased their predictive performance for functional outcome (p=0.013) and mortality (p<0.03) after CE stroke. Conclusions Serum BNP levels are strongly associated with CE stroke and functional outcome at 6 months after ischemic stroke. Inclusion of BNP improved prediction of mortality in patients with CE stroke. PMID:22116811

Rost, Natalia S; Biffi, Alessandro; Cloonan, Lisa; Chorba, John; Kelly, Peter; Greer, David; Ellinor, Patrick; Furie, Karen L

2011-01-01

337

Alterations in blood-brain barrier function following acute hypertension: comparison of the blood-to-brain transfer of horseradish peroxidase with that of alpha-aminisobutyric acid  

SciTech Connect

The blood-brain barrier (BBB) selectively restricts the blood-to-brain passage of many solutes owing to unique properties of cerebrovascular endothelial cell membranes. To date, experimental study of the BBB has been accomplished primarily through the use of two different methodological approaches. Morphological studies have mostly employed large molecular weight (MW) tracers to detect morphological alterations underlying increased permeability. Physiological studies, employing smaller, more physiologic tracers have successfully described, quantitatively, certain functional aspects of blood-to-brain transfer. The current work attempts to merge these two approaches and to consider barrier function/dysfunction from both a morphological and a functional perspective. Specifically, the study compares in rats, following acute hypertension, the cerebrovascular passage of /sup 14/C-alpha-aminoisobutyric acid (AIB) and that of horseradish peroxidase (HRP). The blood-to-brain passage of AIB and HRP were compared following acute hypertension, with regard to both the distributions of the tracer extravasation patterns and the magnitude of tracer extravasation. The results of this study suggest that traditional morphological barrier studies alone do not reveal all aspects of altered barrier status and that multiple mechanisms underlying increased BBB permeability may operate simultaneously during BBB dysfunction.

Ellison, M.D.B.

1985-01-01

338

Delayed convergence between brain network structure and function in rolandic epilepsy  

PubMed Central

Introduction: Rolandic epilepsy (RE) manifests during a critical phase of brain development, and has been associated with language impairments. Concordant abnormalities in structural and functional connectivity (SC and FC) have been described before. As SC and FC are under mutual influence, the current study investigates abnormalities in the SC-FC synergy in RE. Methods: Twenty-two children with RE (age, mean ± SD: 11.3 ± 2.0 y) and 22 healthy controls (age 10.5 ± 1.6 y) underwent structural, diffusion weighted, and resting-state functional magnetic resonance imaging (MRI) at 3T. The probabilistic anatomical landmarks atlas was used to parcellate the (sub)cortical gray matter. Constrained spherical deconvolution tractography and correlation of time series were used to assess SC and FC, respectively. The SC-FC correlation was assessed as a function of age for the non-zero structural connections over a range of sparsity values (0.01–0.75). A modularity analysis was performed on the mean SC network of the controls to localize potential global effects to subnetworks. SC and FC were also assessed separately using graph analysis. Results: The SC-FC correlation was significantly reduced in children with RE compared to healthy controls, especially for the youngest participants. This effect was most pronounced in a left and a right centro-temporal network, as well as in a medial parietal network. Graph analysis revealed no prominent abnormalities in SC or FC network organization. Conclusion: Since SC and FC converge during normal maturation, our finding of reduced SC-FC correlation illustrates impaired synergy between brain structure and function. More specifically, since this effect was most pronounced in the youngest participants, RE may represent a developmental disorder of delayed brain network maturation. The observed effects seem especially attributable to medial parietal connections, which forms an intermediate between bilateral centro-temporal modules of epileptiform activity, and bear relevance for language function.

Besseling, Rene M. H.; Jansen, Jacobus F. A.; Overvliet, Geke M.; van der Kruijs, Sylvie J. M.; Ebus, Saskia C. M.; de Louw, Anton J. A.; Hofman, Paul A. M.; Aldenkamp, Albert P.; Backes, Walter H.

2014-01-01

339

Peptidylglycine ?-amidating monooxygenase heterozygosity alters brain copper handling with region specificity.  

PubMed

Copper (Cu), an essential trace element present throughout the mammalian nervous system, is crucial for normal synaptic function. Neuronal handling of Cu is poorly understood. We studied the localization and expression of Atp7a, the major intracellular Cu transporter in the brain, and its relation to peptidylglycine ?-amidating monooxygenase (PAM), an essential cuproenzyme and regulator of Cu homeostasis in neuroendocrine cells. Based on biochemical fractionation and immunostaining of dissociated neurons, Atp7a was enriched in post-synaptic vesicular fractions. Cu followed a similar pattern, with ~ 20% of total Cu in synaptosomes. A mouse model heterozygous for the Pam gene (PAM+/?) was selectively Cu deficient in the amygdala. As in cortex and hippocampus, Atp7a and PAM expression overlap in the amygdala, with highest expression in interneurons. Messenger RNA levels of Atox-1 and Atp7a, which deliver Cu to the secretory pathway, were reduced in the amygdala but not in the hippocampus in PAM+/? mice, GABAB receptor mRNA levels were similarly affected. Consistent with Cu deficiency, dopamine ?-monooxygenase function was impaired as evidenced by elevated dopamine metabolites in the amygdala, but not in the hippocampus, of PAM+/? mice. These alterations in Cu delivery to the secretory pathway in the PAM+/? amygdala may contribute to the physiological and behavioral deficits observed. Atp7a, a Cu-transporting P-type ATPase, is localized to the trans-Golgi network and to vesicles distributed throughout the dendritic arbor. Tissue-specific alterations in Atp7a expression were found in mice heterozygous for peptidylglycine ?-amidating monooxygenase (PAM), an essential neuropeptide-synthesizing cuproenzyme. Atp7a and PAM are highly expressed in amygdalar interneurons. Reduced amygdalar expression of Atox-1 and Atp7a in PAM heterozygous mice may lead to reduced synaptic Cu levels, contributing to the behavioral and neurochemical alterations seen in these mice. PMID:24032518

Gaier, Eric D; Miller, Megan B; Ralle, Martina; Aryal, Dipendra; Wetsel, William C; Mains, Richard E; Eipper, Betty A

2013-12-01

340

Alzheimer risk variant CLU and brain function during aging  

PubMed Central

Background We examined the effect of the novel Alzheimer's disease (AD) risk variant rs11136000 single nucleotide polymorphism (SNP) in the clusterin gene (CLU) on longitudinal changes in resting state regional cerebral blood flow (rCBF) during normal aging and investigated its influence on cognitive decline in pre-symptomatic stages of disease progression. Methods Subjects were participants in the Baltimore Longitudinal Study of Aging. A subset of 88 cognitively normal older individuals had longitudinal 15O-water PET measurements of rCBF at baseline and up to 8 annual follow-up visits. We also analyzed trajectories of cognitive decline among CLU risk carriers and non-carriers both in individuals who remained cognitively normal (N=599) as well as in those who subsequently converted to mild cognitive impairment (MCI) or AD (N=95). Results Cognitively normal carriers of the CLU risk allele show significant and dose-dependent longitudinal increases in resting state rCBF in brain regions intrinsic to memory processes. There were no differences in trajectories of memory performance between CLU risk carriers and non-carriers who remained cognitively normal. However, in cognitively normal individuals who eventually convert to MCI or AD, CLU risk carriers show faster rates of decline in memory performance relative to non-carriers in the pre-symptomatic stages of disease progression. Conclusions The AD risk variant CLU influences longitudinal changes in brain function in asymptomatic individuals and is associated with faster cognitive decline in pre-symptomatic stages of disease progression. These results suggest mechanisms underlying the role of CLU in AD and may be important in monitoring disease progression in at-risk elderly. PMID:22795969

Thambisetty, Madhav; Beason-Held, Lori L.; An, Yang; Kraut, Michael; Nalls, Michael; Hernandez, Dena G.; Singleton, Andrew B.; Zonderman, Alan B.; Ferrucci, Luigi; Lovestone, Simon; Resnick, Susan M.

2012-01-01

341

Source-based neurofeedback methods using EEG recordings: training altered brain activity in a functional brain source derived from blind source separation  

PubMed Central

A developing literature explores the use of neurofeedback in the treatment of a range of clinical conditions, particularly ADHD and epilepsy, whilst neurofeedback also provides an experimental tool for studying the functional significance of endogenous brain activity. A critical component of any neurofeedback method is the underlying physiological signal which forms the basis for the feedback. While the past decade has seen the emergence of fMRI-based protocols training spatially confined BOLD activity, traditional neurofeedback has utilized a small number of electrode sites on the scalp. As scalp EEG at a given electrode site reflects a linear mixture of activity from multiple brain sources and artifacts, efforts to successfully acquire some level of control over the signal may be confounded by these extraneous sources. Further, in the event of successful training, these traditional neurofeedback methods are likely influencing multiple brain regions and processes. The present work describes the use of source-based signal processing methods in EEG neurofeedback. The feasibility and potential utility of such methods were explored in an experiment training increased theta oscillatory activity in a source derived from Blind Source Separation (BSS) of EEG data obtained during completion of a complex cognitive task (spatial navigation). Learned increases in theta activity were observed in two of the four participants to complete 20 sessions of neurofeedback targeting this individually defined functional brain source. Source-based EEG neurofeedback methods using BSS may offer important advantages over traditional neurofeedback, by targeting the desired physiological signal in a more functionally and spatially specific manner. Having provided preliminary evidence of the feasibility of these methods, future work may study a range of clinically and experimentally relevant brain processes where individual brain sources may be targeted by source-based EEG neurofeedback. PMID:25374520

White, David J.; Congedo, Marco; Ciorciari, Joseph

2014-01-01

342

Transfer Function Specification for the Visualization of Medical Data  

Microsoft Academic Search

The application of transfer functions to map data values to visualproperties as, e.g., color and opacity, is a crucial step in direct volumerendering. Due to the complex relationship between the transferfunction and the resulting image it is usually extremely difficultto model an appropriate mapping. In this paper we presentan advanced transfer function specification scheme for the visualizationof medical data. The

Silvia Castro; Andreas König; Helwig Löffelmann; Eduard Gröller

1998-01-01

343

Changes in Functional Brain Networks following Sports-Related Concussion in Adolescents.  

PubMed

Abstract Sports-related concussion is a major public health issue; however, little is known about the underlying changes in functional brain networks in adolescents following injury. Our aim was to use the tools from graph theory to evaluate the changes in brain network properties following concussion in adolescent athletes. We recorded resting state electroencephalography (EEG) in 33 healthy adolescent athletes and 9 adolescent athletes with a clinical diagnosis of subacute concussion. Graph theory analysis was applied to these data to evaluate changes in brain networks. Global and local metrics of the structural properties of the graph were calculated for each group and correlated with Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT) scores. Brain networks of both groups showed small-world topology with no statistically significant differences in the global metrics; however, significant differences were found in the local metrics. Specifically, in the concussed group, we noted: 1) increased values of betweenness and degree in frontal electrode sites corresponding to the (R) dorsolateral prefrontal cortex and the (R) inferior frontal gyrus and 2) decreased values of degree in the region corresponding to the (R) frontopolar prefrontal cortex. In addition, there was significant negative correlation between degree and hub value, with total symptom score at the electrode site corresponding to the (R) prefrontal cortex. This preliminary report in adolescent athletes shows for the first time that resting-state EEG combined with graph theoretical analysis may provide an objective method of evaluating changes in brain networks following concussion. This approach may be useful in identifying individuals at risk for future injury. PMID:24956041

Virji-Babul, Naznin; Hilderman, Courtney G E; Makan, Nadia; Liu, Aiping; Smith-Forrester, Jenna; Franks, Chris; Wang, Z J

2014-12-01

344

Brain Training Game Improves Executive Functions and Processing Speed in the Elderly: A Randomized Controlled Trial  

Microsoft Academic Search

BackgroundThe beneficial effects of brain training games are expected to transfer to other cognitive functions, but these beneficial effects are poorly understood. Here we investigate the impact of the brain training game (Brain Age) on cognitive functions in the elderly.Methods and ResultsThirty-two elderly volunteers were recruited through an advertisement in the local newspaper and randomly assigned to either of two

Rui Nouchi; Yasuyuki Taki; Hikaru Takeuchi; Hiroshi Hashizume; Yuko Akitsuki; Yayoi Shigemune; Atsushi Sekiguchi; Yuka Kotozaki; Takashi Tsukiura; Yukihito Yomogida; Ryuta Kawashima

2012-01-01

345

Accumulation of waterborne mercury(II) in specific areas of fish brain  

SciTech Connect

The authors used whole-body autoradiography to study the distribution of {sup 203}Hg(II) in the central nervous system of brown (Salmo trutta) and rainbow (Oncorhynchus mykiss) trout. Fish were either exposed to waterborne Hg(II) for 7 and 21 d or they received an intravenous injection of the metal and were sacrificed 1 and 21 d later. Mercury did not accumulate in the brain after intravenous injection, indicating that the blood-brain barrier is impervious to Hg in plasma. In contrast, Hg was accumulated in specific areas of the grain and spinal cord following water exposure. The specificity of the accumulation sites strongly suggests that waterborne Hg was taken up by water-exposed receptor cells of sensory nerves and subsequently transferred toward the brain by axonal transport, a normal physiological process for the transport of organelles and dissolved neuronal constituents along nerve axons. Accumulation of Hg in ventral horn ganglis is probably the result of leaching of metal from blood into muscle followed by uptake in motor plates. Axonal transport allows waterborne inorganic Hg, and possibly other xenobiotics, to circumvent the blood-brain barrier. Considering the importance of complex behavior in the life of fish, and the well-known deleterious effects of mercury on the nervous system, the toxicological significance of this uptake route needs to be assessed.

Rouleau, C.; Borg-Neczak, K.; Gottofrey, J.; Tjaelve, H.

1999-10-01

346

Molecular contributions to neurovascular unit dysfunctions after brain injuries: lessons for target-specific drug development  

PubMed Central

The revised ‘expanded’ neurovascular unit (eNVU) is a physiological and functional unit encompassing endothelial cells, pericytes, smooth muscle cells, astrocytes and neurons. Ischemic stroke and traumatic brain injury are acute brain injuries directly affecting the eNVU with secondary damage, such as blood–brain barrier (BBB) disruption, edema formation and hypoperfusion. BBB dysfunctions are observed at an early postinjury time point, and are associated with eNVU activation of proteases, such as tissue plasminogen activator and matrix metalloproteinases. BBB opening is accompanied by edema formation using astrocytic AQP4 as a key protein regulating water movement. Finally, nitric oxide dysfunction plays a dual role in association with BBB injury and dysregulation of cerebral blood flow. These mechanisms are discussed including all targets of eNVU encompassing endothelium, glial cells and neurons, as well as larger blood vessels with smooth muscle. In fact, the feeding blood vessels should also be considered to treat stroke and traumatic brain injury. This review underlines the importance of the eNVU in drug development aimed at improving clinical outcome after stroke and traumatic brain injury. PMID:24489483

Jullienne, Amandine; Badaut, Jerome

2014-01-01

347

Exosite-driven substrate specificity and function in coagulation.  

PubMed

Macromolecular substrate recognition and serine proteinase specificity lie at the heart of the tightly regulated hemostatic response. Mechanisms established for the less specific serine proteinases of digestion have played a dominant role in guiding investigations of the basis for the narrow specificities exhibited by the coagulation enzymes. These concepts have also dominated the development of specific inhibitors of coagulation for therapeutic purposes. Studies of the enzymology and physical biochemistry of prothrombinase challenge these prevailing ideas by establishing a principal role for exosites within the enzyme in determining substrate recognition and directing the action of the enzyme on its biological substrate. Mechanisms by which narrow protein substrate specificity is achieved by prothrombinase also apply to several other reactions of coagulation. These strategies are increasingly evident in the action of other families of enzymes that act with high specificity on protein substrates. Exosite-driven enzymic function probably represents a widely employed biological strategy for the achievement of high macromolecular substrate specificity. PMID:15634266

Krishnaswamy, S

2005-01-01

348

FINAL REPORT FOR THE CONTRACT BETWEEN POC AND UCSD IMPACT OF INTERMITTENT LIGHT ON NORMAL BRAIN FUNCTION  

E-print Network

FINAL REPORT FOR THE CONTRACT BETWEEN POC AND UCSD IMPACT OF INTERMITTENT LIGHT ON NORMAL BRAIN (blinking) photic stimulation (IPS) on the brain's intrinsic activity. It is well known that the brain that spontaneous rhythmic excitations occur naturally in the brain and are integrally tied to all brain functions

Gorodnitsky, Irina

349

Relationship between brain mitochondrial hexokinase and neuronal function  

Microsoft Academic Search

Mitochondrially bound brain hexokinase is solubilized by anesthetics and this effect has been suggested to contribute to anesthesia. In the present investigation the influence of the metabolic inhibitor 2-deoxy-D-glucose (2-DOG) was studied. An isolated rat brain preparation was used to avoid the contribution of peripheral reactions. Isolated rat brains were perfused for 45 min with media containing 4 mmol\\/l glucose,

J. Krieglstein; G. Sperling; R. Stock

1982-01-01

350

An Input Function Estimation Method for FDG-PET Human Brain Studies 1  

E-print Network

An Input Function Estimation Method for FDG-PET Human Brain Studies 1 Hongbin Guo ,2 Rosemary A Renaut 2 Kewei Chen 3 Abbreviated Title: Input Function Estimation for FDG-PET Abstract Introduction emission tomography (PET) brain studies with bolus injection is presented. Methods: Input data for early

Renaut, Rosemary

351

Neurocognitive and Family Functioning and Quality of Life Among Young Adult Survivors of Childhood Brain Tumors  

Microsoft Academic Search

Many childhood brain tumor survivors experience significant neurocognitive late effects across multiple domains that negatively affect quality of life. A theoretical model of survivorship suggests that family functioning and survivor neurocognitive functioning interact to affect survivor and family outcomes. This paper reviews the types of neurocognitive late effects experienced by survivors of pediatric brain tumors. Quantitative and qualitative data from

Matthew C. Hocking; Wendy L. Hobbie; Janet A. Deatrick; Matthew S. Lucas; Margo M. Szabo; Ellen M. Volpe; Lamia P. Barakat

2011-01-01

352

Spontaneous fluctuations in brain activity observed with functional magnetic resonance imaging  

Microsoft Academic Search

The majority of functional neuroscience studies have focused on the brain's response to a task or stimulus. However, the brain is very active even in the absence of explicit input or output. In this Article we review recent studies examining spontaneous fluctuations in the blood oxygen level dependent (BOLD) signal of functional magnetic resonance imaging as a potentially important and

Michael D. Fox; Marcus E. Raichle

2007-01-01

353

Genetic components of functional connectivity in the brain: the heritability of synchronization likelihood  

Microsoft Academic Search

Cognitive functions require the integrated activity of multiple specialized, distributed brain areas. Such functional coupling depends on the existence of anatomical connections between the various brain areas as well as physiological processes whereby the activity in one area influences the activity in another area. Recently, the Synchronization Likelihood (SL) method was developed as a general method to study both linear

Danielle Posthuma; Geus de J. C. N; Elles J. C. M. Mulder; Smit de D. J; Dorret I. Boomsma; Cornelis J. Stam

2005-01-01

354

An abnormal resting-state functional brain network indicates progression towards Alzheimer's disease.  

PubMed

Brain structure and cognitive function change in the temporal lobe, hippocampus, and prefrontal cortex of patients with mild cognitive impairment and Alzheimer's disease, and brain network-connection strength, network efficiency, and nodal attributes are abnormal. However, existing research has only analyzed the differences between these patients and normal controls. In this study, we constructed brain networks using resting-state functional MRI data that was extracted from four populations (normal controls, patients with early mild cognitive impairment, patients with late mild cognitive impairment, and patients with Alzheimer's disease) using the Alzheimer's Disease Neuroimaging Initiative data set. The aim was to analyze the characteristics of resting-state functional neural networks, and to observe mild cognitive impairment at different stages before the transformation to Alzheimer's disease. Results showed that as cognitive deficits increased across the four groups, the shortest path in the resting-state functional network gradually increased, while clustering coefficients gradually decreased. This evidence indicates that dementia is associated with a decline of brain network efficiency. In addition, the changes in functional networks revealed the progressive deterioration of network function across brain regions from healthy elderly adults to those with mild cognitive impairment and Alzheimer's disease. The alterations of node attributes in brain regions may reflect the cognitive functions in brain regions, and we speculate that early impairments in memory, hearing, and language function can eventually lead to diffuse brain injury and other cognitive impairments. PMID:25206600

Xiang, Jie; Guo, Hao; Cao, Rui; Liang, Hong; Chen, Junjie

2013-10-25

355

From the Left to the Right: How the Brain Compensates Progressive Loss of Language Function  

ERIC Educational Resources Information Center

In normal right-handed subjects language production usually is a function of the left brain hemisphere. Patients with aphasia following brain damage to the left hemisphere have a considerable potential to compensate for the loss of this function. Sometimes, but not always, areas of the right hemisphere which are homologous to language areas of the…

Thiel, Alexander; Habedank, Birgit; Herholz, Karl; Kessler, Josef; Winhuisen, Lutz; Haupt, Walter F.; Heiss, Wolf-Dieter

2006-01-01

356

r Human Brain Mapping 00:000000 (2012) r Key Functional Circuitry Altered in Schizophrenia  

E-print Network

r Human Brain Mapping 00:000­000 (2012) r Key Functional Circuitry Altered in Schizophrenia functional and structural changes in the brain in schizophrenia are of most importance, although the main schizophrenia patients, and func- tional connectivity changes were analyzed using resting-state fMRI data from

Feng, Jianfeng

357

THE DEVELOPMENT OF BRAIN-MACHINE INTERFACING FOR THE RESTORATION OF FUNCTION  

Microsoft Academic Search

New technology is fast approaching that has the potential to restore lost functions to the disabled. The key to this technology is Brain-Machine Interfacing. The purpose of this paper is to demonstrate that Brain-Machine Interfaces (BMIs) provide a vital connection between man and machine instrumental to restoring functions to the disabled. Tapping into the body's neural networks, BMIs translate neural

Tom Daniels; John Selker

358

Development of the Brain's Functional Network Architecture Alecia C. Vogel & Jonathan D. Power &  

E-print Network

REVIEW Development of the Brain's Functional Network Architecture Alecia C. Vogel & Jonathan D of the development of the brain's functional network architecture requires not only an understanding of developmental /Published online: 27 October 2010 # Springer Science+Business Media, LLC 2010 Abstract A full understanding

359

Semantic Relevance, Domain Specificity and the Sensory/Functional Theory of Category-Specificity  

ERIC Educational Resources Information Center

According to the sensory/functional theory of semantic memory, Living items rely more on Sensory knowledge than Non-living ones. The sensory/functional explanation of category-specificity assumes that semantic features are organised on the basis of their content. We report here a study on DAT patients with impaired performance on Living items and…

Sartori, Giuseppe; Gnoato, Francesca; Mariani, Ilenia; Prioni, Sara; Lombardi, Luigi

2007-01-01

360

Motor Imagery Learning Modulates Functional Connectivity of Multiple Brain Systems in Resting State  

PubMed Central

Background Learning motor skills involves subsequent modulation of resting-state functional connectivity in the sensory-motor system. This idea was mostly derived from the investigations on motor execution learning which mainly recruits the processing of sensory-motor information. Behavioral evidences demonstrated that motor skills in our daily lives could be learned through imagery procedures. However, it remains unclear whether the modulation of resting-state functional connectivity also exists in the sensory-motor system after motor imagery learning. Methodology/Principal Findings We performed a fMRI investigation on motor imagery learning from resting state. Based on previous studies, we identified eight sensory and cognitive resting-state networks (RSNs) corresponding to the brain systems and further explored the functional connectivity of these RSNs through the assessments, connectivity and network strengths before and after the two-week consecutive learning. Two intriguing results were revealed: (1) The sensory RSNs, specifically sensory-motor and lateral visual networks exhibited greater connectivity strengths in precuneus and fusiform gyrus after learning; (2) Decreased network strength induced by learning was proved in the default mode network, a cognitive RSN. Conclusions/Significance These results indicated that resting-state functional connectivity could be modulated by motor imagery learning in multiple brain systems, and such modulation displayed in the sensory-motor, visual and default brain systems may be associated with the establishment of motor schema and the regulation of introspective thought. These findings further revealed the neural substrates underlying motor skill learning and potentially provided new insights into the therapeutic benefits of motor imagery learning. PMID:24465577

Zhang, Hang; Long, Zhiying; Ge, Ruiyang; Xu, Lele; Jin, Zhen; Yao, Li; Liu, Yijun

2014-01-01

361

Gene Risk Factors for Age-Related Brain Disorders May Affect Immune System Function  

MedlinePLUS

... age-related brain disorders may affect immune system function June 17, 2014 Scientists have discovered gene variants that affect the function of immune cells in young, healthy people. Interestingly, ...

362

Altered Small-World Efficiency of Brain Functional Networks in Acupuncture at ST36: A Functional MRI Study  

Microsoft Academic Search

BackgroundAcupuncture in humans can produce clinical effects via the central nervous system. However, the neural substrates of acupuncture’s effects remain largely unknown.ResultsWe utilized functional MRI to investigate the topological efficiency of brain functional networks in eighteen healthy young adults who were scanned before and after acupuncture at the ST36 acupoints (ACUP) and its sham point (SHAM). Whole-brain functional networks were

Bo Liu; Jun Chen; Jinhui Wang; Xian Liu; Xiaohui Duan; Xiaojing Shang; Yu Long; Zhiguang Chen; Xiaofang Li; Yan Huang; Yong He

2012-01-01

363

Functional Brain Network Modularity Captures Inter- and Intra-Individual Variation in Working Memory Capacity  

PubMed Central

Background Cognitive abilities, such as working memory, differ among people; however, individuals also vary in their own day-to-day cognitive performance. One potential source of cognitive variability may be fluctuations in the functional organization of neural systems. The degree to which the organization of these functional networks is optimized may relate to the effective cognitive functioning of the individual. Here we specifically examine how changes in the organization of large-scale networks measured via resting state functional connectivity MRI and graph theory track changes in working memory capacity. Methodology/Principal Findings Twenty-two participants performed a test of working memory capacity and then underwent resting-state fMRI. Seventeen subjects repeated the protocol three weeks later. We applied graph theoretic techniques to measure network organization on 34 brain regions of interest (ROI). Network modularity, which measures the level of integration and segregation across sub-networks, and small-worldness, which measures global network connection efficiency, both predicted individual differences in memory capacity; however, only modularity predicted intra-individual variation across the two sessions. Partial correlations controlling for the component of working memory that was stable across sessions revealed that modularity was almost entirely associated with the variability of working memory at each session. Analyses of specific sub-networks and individual circuits were unable to consistently account for working memory capacity variability. Conclusions/Significance The results suggest that the intrinsic functional organization of an a priori defined cognitive control network measured at rest provides substantial information about actual cognitive performance. The association of network modularity to the variability in an individual's working memory capacity suggests that the organization of this network into high connectivity within modules and sparse connections between modules may reflect effective signaling across brain regions, perhaps through the modulation of signal or the suppression of the propagation of noise. PMID:22276205

Stevens, Alexander A.; Tappon, Sarah C.; Garg, Arun; Fair, Damien A.

2012-01-01

364

High-Level CXCR4 Expression Correlates with Brain-Specific Metastasis of Non-Small Cell Lung Cancer  

Microsoft Academic Search

Background  Brain-specific metastasis occurs frequently in lung cancer, and the mechanism is still unclear. The present study was designed\\u000a to investigate the correlation between CXCR4 expression and brain-specific metastasis of non-small cell lung cancer.\\u000a \\u000a \\u000a \\u000a \\u000a Methods  The brain metastatic tumors and lung cancer tissues from 32 patients with solitary brain metastasis of non-small cell lung\\u000a cancer (M1 group), who underwent combined surgical treatment

Gang Chen; Zhou Wang; Xiang-yan Liu; Fan-ying Liu

2011-01-01

365

Differential distribution of mRNA encoding cAMP-specific phosphodiesterase isoforms in the rat brain.  

PubMed

We studied the distributions of four different cyclic AMP-specific phosphodiesterase isoform mRNAs (APDE1-4) and compared them with that of 63 kDa calmodulin-stimulated phosphodiesterase (CPDE) in the rat brain by in situ hybridization histochemistry using specific radiolabeled oligonucleotides. The distribution patterns were unique for all the APDE isoforms examined here. Although no significant signals for APDE1 could be detected anywhere in the rat brain, all other isoforms were expressed ubiquitously but unevenly and showed overlapping distribution patterns. Among all the APDE isoforms studied here, APDE3 showed the strongest and the most extensive expression. Its distribution pattern implies that it may modulate different cellular processes associated with learning and memory. Compared to APDE3, the levels of expression of APDE2 and APDE4 were weaker, the latter showing the weakest expression. Our study suggests that different isoforms of APDE are expressed together in the same class of neurons implying complex interactions among different signaling pathways, thereby mediating distinct and specific functions. PMID:8737663

Iwahashi, Y; Furuyama, T; Tano, Y; Ishimoto, I; Shimomura, Y; Inagaki, S

1996-05-01

366

Maternal Smoking During Pregnancy and Offspring Brain Structure and Function: Review and Agenda for Future Research  

PubMed Central

Introduction: Maternal smoking during pregnancy (MSDP) has been associated with long-term neurobehavioral and cognitive deficits in offspring. Animal models demonstrate alterations in brain structure and function following prenatal nicotine exposure. However, few studies have assessed the relationship between MSDP and brain development in humans. Therefore, the aims of this review are (a) to synthesize findings from the small number of human studies investigating effects of MSDP on offspring brain development and (b) to outline an agenda for future research in this nascent area. Methods: We searched MEDLINE and Psychinfo databases for human studies of MSDP and offspring brain structure and/or function. Results: Eleven studies meeting our search criteria were identified; 6 studies investigated effects of MSDP on brain structure; 5 examined effects on brain function. Across studies, MSDP was associated with decreased volume/thickness of the cerebellum and corpus callosum, increased auditory brainstem responses, and lack of coordination across brain regions during information and auditory processing. Conclusions: Results from the small number of human studies revealed effects of MSDP on brain structure and function, highlighting potential neural pathways linking MSDP and offspring neurobehavioral and cognitive deficits. Given the limited amount of research in this area, we propose an agenda for future research. Gold standard studies would utilize longitudinal designs, integrated biological and maternal report measures of MSDP, and repeated measures of brain structure/function and neurobehavioral deficits across key developmental periods. PMID:22180574

Bublitz, Margaret H.; Stroud, Laura R.

2012-01-01

367

Astrocytes, Synapses and Brain Function: A Computational Approach  

NASA Astrophysics Data System (ADS)

Modulation of synaptic reliability is one of the leading mechanisms involved in long- term potentiation (LTP) and long-term depression (LTD) and therefore has implications in information processing in the brain. A recently discovered mechanism for modulating synaptic reliability critically involves recruitments of astrocytes - star- shaped cells that outnumber the neurons in most parts of the central nervous system. Astrocytes until recently were thought to be subordinate cells merely participating in supporting neuronal functions. New evidence, however, made available by advances in imaging technology has changed the way we envision the role of these cells in synaptic transmission and as modulator of neuronal excitability. We put forward a novel mathematical framework based on the biophysics of the bidirectional neuron-astrocyte interactions that quantitatively accounts for two distinct experimental manifestation of recruitment of astrocytes in synaptic transmission: a) transformation of a low fidelity synapse transforms into a high fidelity synapse and b) enhanced postsynaptic spontaneous currents when astrocytes are activated. Such a framework is not only useful for modeling neuronal dynamics in a realistic environment but also provides a conceptual basis for interpreting experiments. Based on this modeling framework, we explore the role of astrocytes for neuronal network behavior such as synchrony and correlations and compare with experimental data from cultured networks.

Nadkarni, Suhita

2006-03-01

368

Babies and Brains: Habituation in Infant Cognition and Functional Neuroimaging  

PubMed Central

Many prominent studies of infant cognition over the past two decades have relied on the fact that infants habituate to repeated stimuli – i.e. that their looking times tend to decline upon repeated stimulus presentations. This phenomenon had been exploited to reveal a great deal about the minds of preverbal infants. Many prominent studies of the neural bases of adult cognition over the past decade have relied on the fact that brain regions habituate to repeated stimuli – i.e. that the hemodynamic responses observed in fMRI tend to decline upon repeated stimulus presentations. This phenomenon has been exploited to reveal a great deal about the neural mechanisms of perception and cognition. Similarities in the mechanics of these two forms of habituation suggest that it may be useful to relate them to each other. Here we outline this analogy, explore its nuances, and highlight some ways in which the study of habituation in functional neuroimaging could yield novel insights into the nature of habituation in infant cognition – and vice versa. PMID:19104669

Turk-Browne, Nicholas B.; Scholl, Brian J.; Chun, Marvin M.

2008-01-01

369

Gender differences in executive functions following traumatic brain injury  

Microsoft Academic Search

The present study used the National Institute on Disability Rehabilitation and Research (NIDRR) funded Traumatic Brain Injury Model Systems (TBIMS) database to examine the effect of gender on presentation of executive dysfunction following traumatic brain injury (TBI) and variables that might impact the course and degree of recovery. The Wisconsin Card Sort Test (WCST) was chosen as a measure of

Jennifer H. Marwitz; Katrina Lesher; William C. Walker; Tamara Bushnik

2007-01-01

370

Interpreting the effects of altered brain anatomical connectivity on fMRI functional connectivity: a role for computational neural modeling  

PubMed Central

Recently, there have been a large number of studies using resting state fMRI to characterize abnormal brain connectivity in patients with a variety of neurological, psychiatric, and developmental disorders. However, interpreting what the differences in resting state fMRI functional connectivity (rsfMRI-FC) actually reflect in terms of the underlying neural pathology has proved to be elusive because of the complexity of brain anatomical connectivity. The same is the case for task-based fMRI studies. In the last few years, several groups have used large-scale neural modeling to help provide some insight into the relationship between brain anatomical connectivity and the corresponding patterns of fMRI-FC. In this paper we review several efforts at using large-scale neural modeling to investigate the relationship between structural connectivity and functional/effective connectivity to determine how alterations in structural connectivity are manifested in altered patterns of functional/effective connectivity. Because the alterations made in the anatomical connectivity between specific brain regions in the model are known in detail, one can use the results of these simulations to determine the corresponding alterations in rsfMRI-FC. Many of these simulation studies found that structural connectivity changes do not necessarily result in matching changes in functional/effective connectivity in the areas of structural modification. Often, it was observed that increases in functional/effective connectivity in the altered brain did not necessarily correspond to increases in the strength of the anatomical connection weights. Note that increases in rsfMRI-FC in patients have been interpreted in some cases as resulting from neural plasticity. These results suggest that this interpretation can be mistaken. The relevance of these simulation findings to the use of functional/effective fMRI connectivity as biomarkers for brain disorders is also discussed. PMID:24273500

Horwitz, Barry; Hwang, Chuhern; Alstott, Jeff

2013-01-01

371

Non-synaptic receptors and transporters involved in brain functions and targets of drug treatment  

PubMed Central

Beyond direct synaptic communication, neurons are able to talk to each other without making synapses. They are able to send chemical messages by means of diffusion to target cells via the extracellular space, provided that the target neurons are equipped with high-affinity receptors. While synaptic transmission is responsible for the ‘what’ of brain function, the ‘how’ of brain function (mood, attention, level of arousal, general excitability, etc.) is mainly controlled non-synaptically using the extracellular space as communication channel. It is principally the ‘how’ that can be modulated by medicine. In this paper, we discuss different forms of non-synaptic transmission, localized spillover of synaptic transmitters, local presynaptic modulation and tonic influence of ambient transmitter levels on the activity of vast neuronal populations. We consider different aspects of non-synaptic transmission, such as synaptic–extrasynaptic receptor trafficking, neuron–glia communication and retrograde signalling. We review structural and functional aspects of non-synaptic transmission, including (i) anatomical arrangement of non-synaptic release sites, receptors and transporters, (ii) intravesicular, intra- and extracellular concentrations of neurotransmitters, as well as the spatiotemporal pattern of transmitter diffusion. We propose that an effective general strategy for efficient pharmacological intervention could include the identification of specific non-synaptic targets and the subsequent development of selective pharmacological tools to influence them. PMID:20136842

Vizi, ES; Fekete, A; Karoly, R; Mike, A

2010-01-01

372

Insulin regulates brain function, but how does it get there?  

PubMed

We have learned over the last several decades that the brain is an important target for insulin action. Insulin in the central nervous system (CNS) affects feeding behavior and body energy stores, the metabolism of glucose and fats in the liver and adipose, and various aspects of memory and cognition. Insulin may even influence the development or progression of Alzheimer disease. Yet, a number of seemingly simple questions (e.g., What is the pathway for delivery of insulin to the brain? Is insulin's delivery to the brain mediated by the insulin receptor and is it a regulated process? Is brain insulin delivery affected by insulin resistance?) are unanswered. Here we briefly review accumulated findings affirming the importance of insulin as a CNS regulatory peptide, examine the current understanding of how peripheral insulin is delivered to the brain, and identify key gaps in the current understanding of this process. PMID:25414013

Gray, Sarah M; Meijer, Rick I; Barrett, Eugene J

2014-12-01

373

The developmental trajectory of brain-scalp distance from birth through childhood: implications for functional neuroimaging.  

PubMed

Measurements of human brain function in children are of increasing interest in cognitive neuroscience. Many techniques for brain mapping used in children, including functional near-infrared spectroscopy (fNIRS), electroencephalography (EEG), magnetoencephalography (MEG) and transcranial magnetic stimulation (TMS), use probes placed on or near the scalp. The distance between the scalp and the brain is a key variable for these techniques because optical, electrical and magnetic signals are attenuated by distance. However, little is known about how scalp-brain distance differs between different cortical regions in children or how it changes with development. We investigated scalp-brain distance in 71 children, from newborn to age 12 years, using structural T1-weighted MRI scans of the whole head. Three-dimensional reconstructions were created from the scalp surface to allow for accurate calculation of brain-scalp distance. Nine brain landmarks in different cortical regions were manually selected in each subject based on the published fNIRS literature. Significant effects were found for age, cortical region and hemisphere. Brain-scalp distances were lowest in young children, and increased with age to up to double the newborn distance. There were also dramatic differences between brain regions, with up to 50% differences between landmarks. In frontal and temporal regions, scalp-brain distances were significantly greater in the right hemisphere than in the left hemisphere. The largest contributors to developmental changes in brain-scalp distance were increases in the corticospinal fluid (CSF) and inner table of the cranium. These results have important implications for functional imaging studies of children: age and brain-region related differences in fNIRS signals could be due to the confounding factor of brain-scalp distance and not true differences in brain activity. PMID:21957470

Beauchamp, Michael S; Beurlot, Michelle R; Fava, Eswen; Nath, Audrey R; Parikh, Nehal A; Saad, Ziad S; Bortfeld, Heather; Oghalai, John S

2011-01-01

374

Human brain derived cells respond in a type-specific manner after exposure to urban particulate matter (PM).  

PubMed

Exposure to particulate matter (PM), a component of urban air pollution, may cause adverse effects in the brain. Although the exact mechanisms involved are unknown, both oxidative and inflammatory responses have been reported. Since the main route of exposure to particulate matter is through inhalation, there is a potential for compounds to directly enter the brain and alter normal cellular function. Enhancement in both oxidative stress and neuroinflammatory markers has been observed in neurodegenerative disorders and PM-induced potentiation of these events may accelerate the disease process. The objective of this pilot study was to use normal human brain cells, a model system which has not been previously used, to assess cell-type-specific responses after exposure to ultrafine particles (UFP). Human microglia, neurons, and astrocytes were grown separately or as co-cultures and then exposed to aqueous UFP suspensions. Reactive Oxygen Species (ROS) formation and the proinflammatory cytokine tumor necrosis factor alpha (TNF-?) were measured as markers of oxidative stress or inflammation respectively. Our results revealed that after exposure to 2 ?g/ml of particles, normal human neurons exhibit a decrease in ROS formation and an increase in TNF-?. The observed decrease in ROS formation persisted in the presence of glial cells, which contrasts previous studies done in rodent cells reporting that PM-induced microglial activation modulates neuronal responses. Our study indicates that human CNS cells may respond differently compared to rodent cells and that their use may be more predictive in risk assessment. PMID:24999231

Campbell, Arezoo; Daher, Nancy; Solaimani, Parrisa; Mendoza, Kriscelle; Sioutas, Constantinos

2014-10-01

375

REM sleep loss and recovery regulates blood-brain barrier function.  

PubMed

The functions of rapid eye movement (REM) sleep have remained elusive since more than 50 years. Previous reports have identified several independent processes affected by the loss and subsequent recovery of REM sleep (hippocampal neurogenesis, brain stem neuronal cell death, and neurotransmitter content in several brain regions); however, a common underlying mechanism has not been found. We propose that altered brain homeostasis secondary to blood-brain barrier breakdown may explain all those changes induced by REM sleep loss. Therefore, the present report aimed to study the consequences of REM sleep restriction upon blood-brain barrier permeability to Evans blue. REM sleep restriction was induced by the multiple platform technique; male rats were REM sleep restricted 20h daily (with 4h sleep opportunity) during 10 days; control groups included large platform and intact rats. To study blood-brain barrier permeability Evans blue was intracardially administered; stained brains were sliced and photographed for optical density quantification. An independent experiment was carried out to elucidate the mechanism of blood-brain breakdown by transmission electron microscopy. REM sleep restriction increased blood-brain barrier permeability to Evans blue in the whole brain as compared to both control groups. Brief periods of sleep recovery rapidly and effectively restored the severe alteration of blood-brain barrier function by reducing blood-to-brain transfer of Evans blue. The mechanism of blood-brain barrier breakdown involved increased caveolae formation at brain endothelial cells. In conclusion, our data suggest that REM sleep regulates the physical barrier properties of the blood-brain barrier. PMID:23713739

Gómez-González, Beatriz; Hurtado-Alvarado, Gabriela; Esqueda-León, Enrique; Santana-Miranda, Rafael; Rojas-Zamorano, José Ángel; Velázquez-Moctezuma, Javier

2013-08-01

376

Expression of cGMP-Specific Phosphodiesterase 9A mRNA in the Rat Brain  

Microsoft Academic Search

cGMP has been implicated in the regulation of many essential functions in the brain, such as synaptic plasticity, phototrans- duction, olfaction, and behavioral state. Cyclic nucleotide phosphodiesterase (PDE) hydrolysis of cGMP is the major mechanism underlying the clearance of cGMP and is likely to be important in any process that depends on intracellular cGMP. PDE9A has the highest affinity for

Svetlana G. Andreeva; Pieter Dikkes; Paul M. Epstein; Paul A. Rosenberg

2001-01-01

377

Effect of chronic ethanol exposure on mouse brain arachidonic acid specific phospholipase A 2  

Microsoft Academic Search

The enzyme phospholipase A2 (PLA2), which catalyzes the hydrolysis of an ester bond at the sn-2 position of 1,2-sn-diacylglycerols, has been suggested to play an important role in regulating cellular functions. Although ethanol (EtOH)-induced activation of PLA2 activity was reported previously by us in mouse brain (Hungund et al., Neurochem Int25: 321–325, 1994), its subcellular localization and biochemical properties have

Balapal S. Basavarajappa; Thomas B. Cooper; Basalingappa L. Hungund

1998-01-01

378

Brain Maps on the Go: Functional Imaging During Motor Challenge in Animals  

PubMed Central

Brain mapping in the freely-moving animal is useful for studying motor circuits, not only because it avoids the potential confound of sedation or restraints, but because activated brain states may serve to accentuate differences that only manifest partially while a subject is in the resting state. Perfusion or metabolic mapping using autoradiography allows one to examine changes in brain function at the circuit level across the entire brain with a spatial resolution (?100 microns) appropriate for the rat or mouse brain, and a temporal resolution (seconds – minutes) sufficient for capturing acute brain changes. Here we summarize the application of these methods to the functional brain mapping of behaviors involving locomotion of small animals, methods for the three dimensional reconstruction of the brain from autoradiographic sections, voxel based analysis of the whole brain, and generation of maps of the flattened rat cortex. Application of these methods in animal models promises utility in improving our understanding of motor function in the normal brain, and of the effects of neuropathology and treatment interventions such as exercise have on the reorganization of motor circuits. PMID:18554522

Holschneider, DP; Maarek, J-M I

2008-01-01

379

Moderate Doses of Alcohol Disrupt the Functional Organization of the Human Brain  

PubMed Central

Acute alcohol administration decreases overall brain glucose metabolism, which serves as a marker of brain activity. The behavioral effects of alcohol however, are likely to reflect not only changes in regional brain activity but also on the patterns of brain functional organization. Here we assessed the effects of a moderate dose of alcohol on the patterns of brain activity and cerebral differentiation. We measured brain glucose metabolism in 20 healthy controls with PET and FDG during baseline and during alcohol intoxication (0.75 g/kg). We used the coefficient of variation (CV) to assess changes in brain metabolic homogeneity, which we used as a marker for cerebral differentiation. We found that alcohol decreased the CV in the brain and this effect was independent of the decrements in overall glucose metabolism. Our study revealed marked disruption in brain activity during alcohol intoxication including decreases in global and regional brain differentiation, a loss of right versus left brain metabolic laterality and a shift in the predominance of activity from cortical to limbic brain regions. The widespread nature of the changes induced by a moderate dose of alcohol is likely to contribute to the marked disruption of alcohol on behavior, mood, cognition and motor activity. PMID:18280711

Volkow, Nora D.; Ma, Yeming; Zhu, Wei; Fowler, Joanna S.; Li, Juan; Rao, Manlong; Mueller, Klaus; Pradhan, Kith; Wong, Christopher; Wang, Gene-Jack

2008-01-01

380

The Molecular Basis for Kinesin Functional Specificity During Mitosis  

PubMed Central

Microtubule-based motor proteins play key roles during mitosis to assemble the bipolar spindle, define the cell division axis, and align and segregate the chromosomes. The majority of mitotic motors are members of the kinesin superfamily. Despite sharing a conserved catalytic core, each kinesin has distinct functions and localization, and is uniquely regulated in time and space. These distinct behaviors and functional specificity are generated by variations in the enzymatic domain as well as the non-conserved regions outside of the kinesin motor domain and the stalk. These flanking regions can directly modulate the properties of the kinesin motor through dimerization or self-interactions, and can associate with extrinsic factors, such as microtubule or DNA binding proteins, to provide additional functional properties. This review discusses the recently identified molecular mechanisms that explain how the control and functional specification of mitotic kinesins is achieved. © 2013 Wiley Periodicals, Inc. PMID:24039047

Welburn, Julie P I

2013-01-01

381

Erythrocyte DHA level as a biomarker of DHA status in specific brain regions of n-3 long-chain PUFA-supplemented aged rats.  

PubMed

n-3 Long-chain PUFA (n-3 LC-PUFA), particularly EPA and DHA, play a key role in the maintenance of brain functions such as learning and memory that are impaired during ageing. Ageing is also associated with changes in the DHA content of brain membranes that could contribute to memory impairment. Limited studies have investigated the effects of ageing and n-3 LC-PUFA supplementation on both blood and brain fatty acid compositions. Therefore, we assessed the relationship between fatty acid contents in plasma and erythrocyte membranes and those in the hippocampus, striatum and cerebral cortex during ageing, and after a 5-month period of EPA/DHA supplementation in rats. In the blood, ageing was associated with an increase in plasma DHA content, whereas the DHA content remained stable in erythrocyte membranes. In the brain, ageing was associated with a decrease in DHA content, which was both region-specific and phospholipid class-specific. In EPA/DHA-supplemented aged rats, DHA contents were increased both in the blood and brain compared with the control rats. The present results demonstrated that n-3 LC-PUFA level in the plasma was not an accurate biomarker of brain DHA status during ageing. Moreover, we highlighted a positive relationship between the DHA levels in erythrocyte phosphatidylethanolamine (PE) and those in the hippocampus and prefrontal cortex in EPA/DHA-supplemented aged rats. Within the framework of preventive dietary supplementation to delay brain ageing, these results suggest the possibility of using erythrocyte PE DHA content as a reliable biomarker of DHA status in specific brain regions. PMID:25331622

Létondor, Anne; Buaud, Benjamin; Vaysse, Carole; Fonseca, Laurence; Herrouin, Coralie; Servat, Benjamin; Layé, Sophie; Pallet, Véronique; Alfos, Serge

2014-12-01

382

Spatially Aggregated Multi-Class Pattern Classification in Functional MRI using Optimally Selected Functional Brain Areas  

PubMed Central

In previous works, boosting aggregation of classifier outputs from discrete brain areas has been demonstrated to reduce dimensionality, and improve the robustness and accuracy of fMRI classification. However, dimensionality reduction and classification of mixed activation patterns of multiple classes remain challenging. In the present study, the goals were (a) to reduce dimensionality by combining feature reduction at the voxel level and backward elimination of optimally aggregated classifiers at the region level, (b) to compare region selection for spatially aggregated classification using boosting and partial least squares regression methods and (c) to resolve mixed activation patterns using probabilistic prediction of individual tasks. Brain activation maps from interleaved visual, motor, auditory and cognitive tasks were segmented into 144 functional regions. Feature selection reduced the number of feature voxels by more than 50%, leaving 95 regions. The two aggregation approaches further reduced the number of regions to 30, resulting in more than 75% reduction of classification time and misclassification rates of less than 3%. Boosting and partial least squares (PLS) were compared to select the most discriminative and the most task correlated regions, respectively. Successful task prediction in mixed activation patterns was feasible within the first block of task activation in real time fMRI experiments. This methodology is suitable for sparsifying activation patterns in real-time fMRI and for neurofeedback from distributed networks of brain activation. PMID:22902471

Zheng, Weili; Ackley, Elena S.; Martinez-Ramon, Manel; Posse, Stefan

2012-01-01

383

Modeling dynamic functional information flows on large-scale brain networks.  

PubMed

Growing evidence from the functional neuroimaging field suggests that human brain functions are realized via dynamic functional interactions on large-scale structural networks. Even in resting state, functional brain networks exhibit remarkable temporal dynamics. However, it has been rarely explored to computationally model such dynamic functional information flows on large-scale brain networks. In this paper, we present a novel computational framework to explore this problem using multimodal resting state fMRI (R-fMRI) and diffusion tensor imaging (DTI) data. Basically, recent literature reports including our own studies have demonstrated that the resting state brain networks dynamically undergo a set of distinct brain states. Within each quasi-stable state, functional information flows from one set of structural brain nodes to other sets of nodes, which is analogous to the message package routing on the Internet from the source node to the destination. Therefore, based on the large-scale structural brain networks constructed from DTI data, we employ a dynamic programming strategy to infer functional information transition routines on structural networks, based on which hub routers that most frequently participate in these routines are identified. It is interesting that a majority of those hub routers are located within the default mode network (DMN), revealing a possible mechanism of the critical functional hub roles played by the DMN in resting state. Also, application of this framework on a post trauma stress disorder (PTSD) dataset demonstrated interesting difference in hub router distributions between PTSD patients and healthy controls. PMID:24579202

Lv, Peili; Guo, Lei; Hu, Xintao; Li, Xiang; Jin, Changfeng; Han, Junwei; Li, Lingjiang; Liu, Tianming

2013-01-01

384

A primer on brain-machine interfaces, concepts, and technology: a key element in the future of functional neurorestoration.  

PubMed

Conventionally, the practice of neurosurgery has been characterized by the removal of pathology, congenital or acquired. The emerging complement to the removal of pathology is surgery for the specific purpose of restoration of function. Advents in neuroscience, technology, and the understanding of neural circuitry are creating opportunities to intervene in disease processes in a reparative manner, thereby advancing toward the long-sought-after concept of neurorestoration. Approaching the issue of neurorestoration from a biomedical engineering perspective is the rapidly growing arena of implantable devices. Implantable devices are becoming more common in medicine and are making significant advancements to improve a patient's functional outcome. Devices such as deep brain stimulators, vagus nerve stimulators, and spinal cord stimulators are now becoming more commonplace in neurosurgery as we utilize our understanding of the nervous system to interpret neural activity and restore function. One of the most exciting prospects in neurosurgery is the technologically driven field of brain-machine interface, also known as brain-computer interface, or neuroprosthetics. The successful development of this technology will have far-reaching implications for patients suffering from a great number of diseases, including but not limited to spinal cord injury, paralysis, stroke, or loss of limb. This article provides an overview of the issues related to neurorestoration using implantable devices with a specific focus on brain-machine interface technology. PMID:23333985

Lee, Brian; Liu, Charles Y; Apuzzo, Michael L J

2013-01-01

385

Purification, characterization and developmental expression of a brain-specific chondroitin sulfate proteoglycan, 6B4 proteoglycan\\/phosphacan  

Microsoft Academic Search

A large brain-specific chondroitin sulfate proteoglycan, identified with monoclonal antibody 6B4 (6B4 proteoglycan\\/phosphacan), was isolated from rat brain. Soluble proteoglycans in the phosphate-buffered saline extract from 20-day-old rat whole brain were fractionated by anion exchange chromatography and CsCl density gradient centrifugation. 6B4 proteoglycan was further purified by gel filtration and additional ion exchange chromatography. The molecular mass of 6B4 proteoglycan

N. Maeda; H. Hamanaka; A. Oohira; M. Noda

1995-01-01

386

Microwave beamforming for non-invasive patient-specific hyperthermia treatment of pediatric brain cancer  

NASA Astrophysics Data System (ADS)

We present a numerical study of an array-based microwave beamforming approach for non-invasive hyperthermia treatment of pediatric brain tumors. The transmit beamformer is designed to achieve localized heating—that is, to achieve constructive interference and selective absorption of the transmitted electromagnetic waves at the desired focus location in the brain while achieving destructive interference elsewhere. The design process takes into account patient-specific and target-specific propagation characteristics at 1 GHz. We evaluate the effectiveness of the beamforming approach using finite-difference time-domain simulations of two MRI-derived child head models from the Virtual Family (IT'IS Foundation). Microwave power deposition and the resulting steady-state thermal distribution are calculated for each of several randomly chosen focus locations. We also explore the robustness of the design to mismatch between the assumed and actual dielectric properties of the patient. Lastly, we demonstrate the ability of the beamformer to suppress hot spots caused by pockets of cerebrospinal fluid (CSF) in the brain. Our results show that microwave beamforming has the potential to create localized heating zones in the head models for focus locations that are not surrounded by large amounts of CSF. These promising results suggest that the technique warrants further investigation and development.

Burfeindt, Matthew J.; Zastrow, Earl; Hagness, Susan C.; Van Veen, Barry D.; Medow, Joshua E.

2011-05-01

387

Deep brain optical measurements of cell type–specific neural activity in behaving mice  

PubMed Central

Recent advances in genetically encoded fluorescent sensors enable the monitoring of cellular events from genetically defined groups of neurons in vivo. In this protocol, we describe how to use a time-correlated single-photon counting (tcspc)–based fiber optics system to measure the intensity, emission spectra and lifetime of fluorescent biosensors expressed in deep brain structures in freely moving mice. When combined with cre-dependent selective expression of genetically encoded ca2+ indicators (GecIs), this system can be used to measure the average neural activity from a specific population of cells in mice performing complex behavioral tasks. as an example, we used viral expression of GcaMps in striatal projection neurons (spns) and recorded the fluorescence changes associated with calcium spikes from mice performing a lever-pressing operant task. the whole procedure, consisting of virus injection, behavior training and optical recording, takes 3–4 weeks to complete. With minor adaptations, this protocol can also be applied to recording cellular events from other cell types in deep brain regions, such as dopaminergic neurons in the ventral tegmental area. the simultaneously recorded fluorescence signals and behavior events can be used to explore the relationship between the neural activity of specific brain circuits and behavior. PMID:24784819

Cui, Guohong; Jun, Sang Beom; Jin, Xin; Luo, Guoxiang; Pham, Michael D; Lovinger, David M; Vogel, Steven S; Costa, Rui M

2014-01-01

388

Error estimates and specification parameters for functional renormalization  

NASA Astrophysics Data System (ADS)

We present a strategy for estimating the error of truncated functional flow equations. While the basic functional renormalization group equation is exact, approximated solutions by means of truncations do not only depend on the choice of the retained information, but also on the precise definition of the truncation. Therefore, results depend on specification parameters that can be used to quantify the error of a given truncation. We demonstrate this for the BCS-BEC crossover in ultracold atoms. Within a simple truncation the precise definition of the frequency dependence of the truncated propagator affects the results, indicating a shortcoming of the choice of a frequency independent cutoff function.

Schnoerr, David; Boettcher, Igor; Pawlowski, Jan M.; Wetterich, Christof

2013-07-01

389

Subcortical physiology deformed into a patient-specific brain atlas for image-guided stereotaxy  

NASA Astrophysics Data System (ADS)

Stereotactic neurosurgery for movement disorders involves the accurate localization of functionally distinct subcortical anatomy that appears homogeneous on magnetic resonance or computed tomographic images. To aid localization of these surgical targets on patient images, we have developed a visualization oriented searchable and expandable database of functional organization representing bilaterally the sensorimotor thalamus, pallidum, internal capsule, and subthalamic nucleus. Data were obtained through microelectrode recording and stimulation mapping routinely performed during 123 functional stereotactic procedures. Electrophysiologic data were standardized using a multi-parameter coding system and annotated to their respective MRIs at the appropriate position in patient stereotactic space. To accommodate for normal anatomical variability, we have developed an intensity-based nonlinear registration algorithm that rapidly warps a patient's volumetric MRI to a high-resolution MRI average brain. The annotated functional data are subsequently transformed into the average brain coordinate system using the displacement grids generated by the algorithm. When the database is searched, clustering of like inter-patient physiologic responses within target anatomy and adjacent structures is revealed. These data may in turn be registered to a preoperative MRI using a desktop computer enabling prior to surgery interactive delineation of surgical targets. The database is expandable, fully searchable, and provides a visual 3D representation of subcortical functional organization.

Finnis, Kirk; Starreveld, Yves P.; Parrent, Andrew; Peters, Terence M.

2002-05-01

390

Effects of bisphenol A and triclocarban on brain-specific expression of aromatase in early zebrafish embryos  

PubMed Central

Estrogen regulates numerous developmental and physiological processes. Most effects are mediated by estrogen receptors (ERs), which function as ligand-regulated transcription factors. Estrogen also regulates the activity of GPR30, a membrane-associated G protein-coupled receptor. Many different types of environmental contaminants can activate ERs; some can bind GPR30 as well. There is growing concern that exposure to some of these compounds, termed xenoestrogens, is interfering with the behavior and reproductive potential of numerous wildlife species, as well as affecting human health. Here, we investigated how two common, environmentally pervasive chemicals affect the in vivo expression of a known estrogen target gene in the brain of developing zebrafish embryos, aromatase AroB, which converts androgens to estrogens. We confirm that, like estrogen, the well-studied xenoestrogen bisphenol A (BPA, a plastics monomer), induces strong brain-specific overexpression of aromatase. Experiments using ER- and GPR30-selective modulators argue that this induction is largely through nuclear ERs. BPA induces dramatic overexpression of AroB RNA in the same subregions of the developing brain as estrogen. The antibacterial triclocarban (TCC) by itself stimulates AroB expression only slightly, but TCC strongly enhances the overexpression of AroB that is induced by exogenous estrogen. Thus, both BPA and TCC have the potential to elevate levels of aromatase and, thereby, levels of endogenous estrogens in the developing brain. In contrast to estrogen, BPA-induced AroB overexpression was suppressed by TCC. These results indicate that exposures to combinations of certain hormonally active pollutants can have outcomes that are not easily predicted from their individual effects. PMID:22006313

Chung, Eunah; Genco, Maria C.; Megrelis, Laura; Ruderman, Joan V.

2011-01-01

391

Effects of bisphenol A and triclocarban on brain-specific expression of aromatase in early zebrafish embryos.  

PubMed

Estrogen regulates numerous developmental and physiological processes. Most effects are mediated by estrogen receptors (ERs), which function as ligand-regulated transcription factors. Estrogen also regulates the activity of GPR30, a membrane-associated G protein-coupled receptor. Many different types of environmental contaminants can activate ERs; some can bind GPR30 as well. There is growing concern that exposure to some of these compounds, termed xenoestrogens, is interfering with the behavior and reproductive potential of numerous wildlife species, as well as affecting human health. Here, we investigated how two common, environmentally pervasive chemicals affect the in vivo expression of a known estrogen target gene in the brain of developing zebrafish embryos, aromatase AroB, which converts androgens to estrogens. We confirm that, like estrogen, the well-studied xenoestrogen bisphenol A (BPA, a plastics monomer), induces strong brain-specific overexpression of aromatase. Experiments using ER- and GPR30-selective modulators argue that this induction is largely through nuclear ERs. BPA induces dramatic overexpression of AroB RNA in the same subregions of the developing brain as estrogen. The antibacterial triclocarban (TCC) by itself stimulates AroB expression only slightly, but TCC strongly enhances the overexpression of AroB that is induced by exogenous estrogen. Thus, both BPA and TCC have the potential to elevate levels of aromatase and, thereby, levels of endogenous estrogens in the developing brain. In contrast to estrogen, BPA-induced AroB overexpression was suppressed by TCC. These results indicate that exposures to combinations of certain hormonally active pollutants can have outcomes that are not easily predicted from their individual effects. PMID:22006313

Chung, Eunah; Genco, Maria C; Megrelis, Laura; Ruderman, Joan V

2011-10-25

392

Researchers Create Functional 3-D Brain-Like Tissue  

MedlinePLUS

... service of the U.S. National Library of Medicine National Institutes of Health Home About ... allows for study of brain injuries and potential treatments (*this news item will not be available after ...

393

Scientists Examine How Brain Structure and Function Change During Adolescence  

MedlinePLUS

... who moderated a press conference on adolescence at Neuroscience 2012. As a result, adolescents represent a fascinating ... and colleagues at the UCL Institute of Cognitive Neuroscience in London and the NIMH took multiple brain ...