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1

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

2

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

3

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

4

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

5

Understanding the potency of stressful early life experiences on brain and body function  

PubMed Central

Early life experiences have powerful effects on the brain and body lasting throughout the entire lifespan and influencing brain function, behavior and the risk for a number of systemic and mental disorders. Animal models of early life adversity are providing mechanistic insights, including glimpses into the fascinating world that is now called “epigenetics” as well as the role of naturally occurring alleles of a number of genes. These studies also provide insights into the adaptive value, as well as the negative consequences, of early life stress, exposure to novelty, and poor vs good quality maternal care. Animal models begin to provide a mechanistic basis for understanding how brain development and physiological functioning is affected in children exposed to early life abuse and neglect, where there is a burgeoning literature on the consequences for physical health and emotional and cognitive development. An important goal is to identify interventions that are likely to be most effective in early life and some guidelines are provided. PMID:18803958

McEwen, Bruce S.

2008-01-01

6

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

7

Understanding brain networks and brain organization  

NASA Astrophysics Data System (ADS)

What is the relationship between brain and behavior? The answer to this question necessitates characterizing the mapping between structure and function. The aim of this paper is to discuss broad issues surrounding the link between structure and function in the brain that will motivate a network perspective to understanding this question. However, as others in the past, I argue that a network perspective should supplant the common strategy of understanding the brain in terms of individual regions. Whereas this perspective is needed for a fuller characterization of the mind-brain, it should not be viewed as panacea. For one, the challenges posed by the many-to-many mapping between regions and functions is not dissolved by the network perspective. Although the problem is ameliorated, one should not anticipate a one-to-one mapping when the network approach is adopted. Furthermore, decomposition of the brain network in terms of meaningful clusters of regions, such as the ones generated by community-finding algorithms, does not by itself reveal “true” subnetworks. Given the hierarchical and multi-relational relationship between regions, multiple decompositions will offer different “slices” of a broader landscape of networks within the brain. Finally, I described how the function of brain regions can be characterized in a multidimensional manner via the idea of diversity profiles. The concept can also be used to describe the way different brain regions participate in networks.

Pessoa, Luiz

2014-09-01

8

Neural Circuit Function Seeking to understand how the brain recognizes and responds to the external world by  

E-print Network

#12;3 Neural Circuit Function Seeking to understand how the brain recognizes and responds. We study the function and development of the neural circuits responsible for the emotional control of behaviors. Our research aim is to reveal the molecular mechanisms of circuit development in the thalamus

Kazama, Hokto

9

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

10

Understanding brain dysfunction in sepsis  

PubMed Central

Sepsis often is characterized by an acute brain dysfunction, which is associated with increased morbidity and mortality. Its pathophysiology is highly complex, resulting from both inflammatory and noninflammatory processes, which may induce significant alterations in vulnerable areas of the brain. Important mechanisms include excessive microglial activation, impaired cerebral perfusion, blood–brain-barrier dysfunction, and altered neurotransmission. Systemic insults, such as prolonged inflammation, severe hypoxemia, and persistent hyperglycemia also may contribute to aggravate sepsis-induced brain dysfunction or injury. The diagnosis of brain dysfunction in sepsis relies essentially on neurological examination and neurological tests, such as EEG and neuroimaging. A brain MRI should be considered in case of persistent brain dysfunction after control of sepsis and exclusion of major confounding factors. Recent MRI studies suggest that septic shock can be associated with acute cerebrovascular lesions and white matter abnormalities. Currently, the management of brain dysfunction mainly consists of control of sepsis and prevention of all aggravating factors, including metabolic disturbances, drug overdoses, anticholinergic medications, withdrawal syndromes, and Wernicke’s encephalopathy. Modulation of microglial activation, prevention of blood–brain-barrier alterations, and use of antioxidants represent relevant therapeutic targets that may impact significantly on neurologic outcomes. In the future, investigations in patients with sepsis should be undertaken to reduce the duration of brain dysfunction and to study the impact of this reduction on important health outcomes, including functional and cognitive status in survivors. PMID:23718252

2013-01-01

11

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

12

Understanding Brain, Cognition, and Behavior in Complex Dynamic Environments  

Microsoft Academic Search

Many challenges remain for understanding how the human brain functions in complex dynamic environments. For example, how do\\u000a we measure brain physiology of humans interacting in their natural environments where data acquisition systems are intrusive\\u000a and environmental and biological artifacts severely confound brain source signals? How do we understand the full context within\\u000a which the human brain is operating? How

Scott E. Kerick; Kaleb Mcdowell

2009-01-01

13

Understanding the changing adolescent brain  

Microsoft Academic Search

Summary Recent brain imaging studies have demonstrated that the human brain continues to develop throughout the adolescent years. Although there are differences between male and female teenagers in terms of the time course of neural development, similar brain areas undergo significant restructuring in both sexes. Brain regions in which development is particularly protracted include the prefrontal cortex and the temporalparietal

Stephanie Burnett; Catherine Sebastian

14

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

15

From `Understanding the Brain by Creating the Brain' towards manipulative neuroscience  

E-print Network

, the development of `brain- style' computer systems, with human-like intel makehumanoidrobots solve tasks typically solved by the human brain by essentially the same principles. I postulate inferior to humans in most brain functions, such as natural language processing, visual scene understanding

Kawato, Mitsuo

16

Contributions from research on anger and cognitive dissonance to understanding the motivational functions of asymmetrical frontal brain activity  

Microsoft Academic Search

Research has suggested that approach-related positive emotions are associated with greater left frontal brain activity and that withdrawal-related negative emotions are associated with greater right frontal brain activity. Different explanations have been proposed. One posits that frontal asymmetry is due to emotional valence (positivity\\/negativity), one posits that frontal asymmetry is due to motivational direction (approach\\/withdrawal), and one posits that frontal

Eddie Harmon-Jones

2004-01-01

17

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

18

Understanding the Mind by Measuring the Brain  

E-print Network

Understanding the Mind by Measuring the Brain Lessons From Measuring Behavior (Commentary on Vul et al., 2009) Lisa Feldman Barrett Boston College, Massachusetts General Hospital, and Harvard Medical in a quest to understand the mind. Three lessons from psy- chometrics are discussed. In 1862, Wilhelm Wundt

Barrett, Lisa Feldman

19

[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

20

Understanding Brain, Mind and Soul: Contributions from Neurology and Neurosurgery  

PubMed Central

Treatment of diseases of the brain by drugs or surgery necessitates an understanding of its structure and functions. The philosophical neurosurgeon soon encounters difficulties when localising the abstract concepts of mind and soul within the tangible 1300-gram organ containing 100 billion neurones. Hippocrates had focused attention on the brain as the seat of the mind. The tabula rasa postulated by Aristotle cannot be localised to a particular part of the brain with the confidence that we can localise spoken speech to Broca’s area or the movement of limbs to the contralateral motor cortex. Galen’s localisation of imagination, reasoning, judgement and memory in the cerebral ventricles collapsed once it was evident that the functional units–neurones–lay in the parenchyma of the brain. Experiences gained from accidental injuries (Phineas Gage) or temporal lobe resection (William Beecher Scoville); studies on how we see and hear and more recent data from functional magnetic resonance studies have made us aware of the extensive network of neurones in the cerebral hemispheres that subserve the functions of the mind. The soul or atman, credited with the ability to enliven the body, was located by ancient anatomists and philosophers in the lungs or heart, in the pineal gland (Descartes), and generally in the brain. When the deeper parts of the brain came within the reach of neurosurgeons, the brainstem proved exceptionally delicate and vulnerable. The concept of brain death after irreversible damage to it has made all of us aware of ‘the cocktail of brain soup and spark’ in the brainstem so necessary for life. If there be a soul in each of us, surely, it is enshrined here. PMID:21694966

Pandya, Sunil K.

2011-01-01

21

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

22

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

23

[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

24

The Energetic Brain: Understanding and Managing ADHD  

ERIC Educational Resources Information Center

ADHD affects millions of people-some 3 to 5% of the general population. Written by a neuroscientist who has studied ADHD, a clinician who has diagnosed and treated it for 30 years, and a special educator who sees it daily, "The Energetic Brain" provides the latest information from neuroscience on how the ADHD brain works and shows how to harness…

Reynolds, Cecil R.; Vannest, Kimberly J.; Harrison, Judith R.

2012-01-01

25

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

26

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

27

Understanding Traumatic Brain Injury: An Introduction  

ERIC Educational Resources Information Center

This article is the first of a multi-part series on traumatic brain injury (TBI). Historically, TBI has received very limited national public policy attention and support. However since it has become the signature injury of the military conflicts in Iraq and Afghanistan, TBI has gained the attention of elected officials, military leaders,…

Trudel, Tina M.; Scherer, Marcia J.; Elias, Eileen

2009-01-01

28

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

29

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

30

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

31

How Brain Research Has Changed Our Understanding of Giftedness  

ERIC Educational Resources Information Center

Understanding brain development and its relationship to intelligence promotes a clearer understanding of giftedness. Children are born with unique patterns and pathways which provide potential for high levels of intelligence. Parents and teachers contribute to the development of giftedness with experiences that are appropriately stimulating. It is…

Clark, Barbara

2009-01-01

32

New Advances in Understanding Sensitive Periods in Brain Development  

Microsoft Academic Search

Is a dog ever too old to learn new tricks? We review recent findings on sensitive periods in brain development, ranging from sensory processing to high-level cognitive abilities in humans. We conclude that there are multiple varieties of, and mechanisms underlying, these changes. However, many sensitive periods may be a consequence of the basic processes underlying postnatal functional brain development.

Michael S. C. Thomas; Mark H. Johnson

2008-01-01

33

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

34

Understanding the Executive Functioning Heterogeneity in Schizophrenia  

ERIC Educational Resources Information Center

Schizophrenia is characterized by heterogeneous brain abnormalities involving cerebral regions implied in the executive functioning. The dysexecutive syndrome is one of the most prominent and functionally cognitive features of schizophrenia. Nevertheless, it is not clear to what extend executive deficits are heterogeneous in schizophrenia…

Raffard, Stephane; Bayard, Sophie

2012-01-01

35

Understanding human functioning using graphical models  

Microsoft Academic Search

BACKGROUND: Functioning and disability are universal human experiences. However, our current understanding of functioning from a comprehensive perspective is limited. The development of the International Classification of Functioning, Disability and Health (ICF) on the one hand and recent developments in graphical modeling on the other hand might be combined and open the door to a more comprehensive understanding of human

Markus Kalisch; Bernd AG Fellinghauer; Eva Grill; Marloes H Maathuis; Ulrich Mansmann; Peter Bühlmann; Gerold Stucki

2010-01-01

36

From "Understanding the Brain by Creating the Brain" toward Manipulative Neuroscience  

E-print Network

. In Particular, the development of "brain-style" computer systems, with human-like intellectual and emotional to the extent that we can make humanoid robots solve tasks typically solved by the human brain by using, but they are still greatly inferior to humans in most brain functions such as natural language processing, visual

Kawato, Mitsuo

37

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

38

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

39

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

40

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

41

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

42

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

43

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

44

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

45

Art Therapy and the Brain: An Attempt to Understand the Underlying Processes of Art Expression in Therapy  

ERIC Educational Resources Information Center

The application of new techniques in brain imaging has expanded the understanding of the different functions and structures of the brain involved in information processing. This paper presents the main areas and functions activated in emotional states, the formation of memories, and the processing of motor, visual, and somatosensory information.…

Lusebrink, Vija B.

2004-01-01

46

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

47

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

48

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

49

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

50

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

51

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

52

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

53

Ad cerebrum per scientia: Ira Hirsh, psychoacoustics, and new approaches to understanding the human brain  

NASA Astrophysics Data System (ADS)

As Research Director of CID, Ira emphasized the importance of combining information from biology with rigorous studies of behavior, such as psychophysics, to better understand how the brain and body accomplish the goals of everyday life. In line with this philosophy, my doctoral dissertation sought to explain brain functional asymmetries (studied with dichotic listening) in terms of the physical dimensions of a library of test sounds designed to represent a speech-music continuum. Results highlighted individual differences plus similarities in terms of patterns of relative ear advantages, suggesting an organizational basis for brain asymmetries depending on physical dimensions of stimulus and gesture with analogs in auditory, visual, somatosensory, and motor systems. My subsequent work has employed a number of noninvasive methods (OAEs, EPs, qEEG, PET, MRI) to explore the neurobiological bases of individual differences in general and functional asymmetries in particular. This research has led to (1) the AXS test battery for assessing the neurobiology of human sensory-motor function; (2) the handshaking model of brain function, describing dynamic relations along all three body/brain axes; (3) the four-domain EPIC model of functional asymmetries; and (4) the trimodal brain, a new model of individual differences based on psychoimmunoneuroendocrinology.

Lauter, Judith

2002-05-01

54

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

55

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

56

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

57

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

58

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

59

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

60

Culture, Executive Function, and Social Understanding  

ERIC Educational Resources Information Center

Much of the evidence from the West has shown links between children's developing self-control (executive function), their social experiences, and their social understanding (Carpendale & Lewis, 2006, chapters 5 and 6), across a range of cultures including China. This chapter describes four studies conducted in three Oriental cultures, suggesting…

Lewis, Charlie; Koyasu, Masuo; Oh, Seungmi; Ogawa, Ayako; Short, Benjamin; Huang, Zhao

2009-01-01

61

Neuroimaging Studies of Normal Brain Development and Their Relevance for Understanding Childhood Neuropsychiatric Disorders  

PubMed Central

Objective To review the maturational events that occur during prenatal and postnatal brain development and to present neuroimaging findings from studies of healthy individuals that identify the trajectories of normal brain development. Method Histological and postmortem findings of early brain development are presented, followed by a discussion of anatomical, diffusion tensor, proton spectroscopy, and functional imaging findings from studies of healthy individuals, with special emphasis on longitudinal data. Results Early brain development occurs through a sequence of major events, beginning with the formation of the neural tube and ending with myelination. Brain development at a macroscopic level typically proceeds first in sensorimotor areas, spreading subsequently and progressively into dorsal and parietal, superior temporal, and dorsolateral prefrontal cortices throughout later childhood and adolescence. These patterns of anatomical development parallel increasing activity in frontal cortices that subserves the development of higher-order cognitive functions during late childhood and adolescence. Disturbances in these developmental patterns seem to be involved centrally in the pathogenesis of various childhood psychiatric disorders including childhood-onset schizophrenia, attention-deficit/hyperactivity disorder, developmental dyslexia, Tourette’s syndrome, and bipolar disorder. Conclusions Advances in imaging techniques have enhanced our understanding of normal developmental trajectories in the brain, which may improve insight into the abnormal patterns of development in various childhood psychiatric disorders. PMID:18833009

Marsh, Rachel; Gerber, Andrew J.; Peterson, Bradley S.

2009-01-01

62

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

63

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

64

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

65

REVIEW Open Access Understanding brain dysfunction in sepsis  

E-print Network

and noninflammatory processes, which may induce significant alterations in vulnerable areas of the brain. Important. The diagnosis of brain dysfunction in sepsis relies essentially on neurological examination and neurological tests, such as EEG and neuroimaging. A brain MRI should be considered in case of persistent brain

Paris-Sud XI, Université de

66

Understanding the Functions of Proteins and DNA  

NSDL National Science Digital Library

This overview provides a sequence of learning activities to help students understand that proteins and DNA are not just abstract concepts in biology textbooks, but rather crucial components of our bodies that affect functions and characteristics that students are familiar with. Students learn about how proteins contribute to the digestion of food and to characteristics such as albinism, sickle cell anemia and hemophilia. Then, students learn about the relationship between the genetic information in DNA and the different versions of these proteins. The discussion, web-based, and hands-on learning activities presented are appropriate for an introductory unit on biological molecules or as an introduction to a unit on molecular biology.

Waldron, Ingrid

67

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

68

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

69

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

70

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

71

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

72

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

73

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

74

Understanding How to Design Complex Brain-Controlled Applications  

E-print Network

: Examples of P300-based brain-controlled interfaces. teraction will have an even larger impact­15, 2010. Atlanta, Georgia, USA ACM 978-1-60558-930-5/10/04. Introduction Most of the effort in brain-computer of research directed at developing applica- tions and interaction methods specifically for brain-computer

Chen, Yiling

75

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

76

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

77

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

78

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

79

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

80

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

81

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

82

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

83

Integrating Functional Brain Neuroimaging and Developmental Cognitive Neuroscience in Child Psychiatry Research  

ERIC Educational Resources Information Center

The use of cognitive neuroscience and functional brain neuroimaging to understand brain dysfunction in pediatric psychiatric disorders is discussed. Results show that bipolar youths demonstrate impairment in affective and cognitive neural systems and in these two circuits' interface. Implications for the diagnosis and treatment of psychiatric…

Pavuluri, Mani N.; Sweeney, John A.

2008-01-01

84

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

85

Famous Russian brains: historical attempts to understand intelligence.  

PubMed

Russian scientists are certainly among those who contributed actively to the search for the neuroanatomical basis of exceptional mental capacity and talent. Research into brain anatomy was one of the topics of special interest in various Russian universities. A number of independent reports on the study of famous Russian brains appeared both in Russia and abroad. Collecting and mapping brains of elite Russians in a structured manner began in Moscow in 1924 with the brain of V. I. Lenin. In 1928, the Moscow Brain Research Institute was founded, the collection of which includes the brains of several prominent Russian neuroscientists, including V. M. Bekhterev, G. I. Rossolimo, L. S. Vygotsky and I. P. Pavlov. The fact that the brain of two of the most outstanding scholars of Russian neurology and psychiatry, A. Ya. Kozhevnikov (1836-1902) and S. S. Korsakov (1854-1900), have been studied is largely unknown. A report of the results of this study was published by A. A. Kaputsin in 1925 providing a detailed neuroanatomical assessment of the brains. A considerable weight, a predominance of the left hemisphere and a particularly complex convolution of the frontal and parietal lobes of both brains were reported, the assumption being that these brain parameters can serve as an indicator of mental capacity. The names Kozhevnikov and Korsakov are among those most cherished by Russian neuroscientists; they are also familiar to Western colleagues. The (re)discovery of the records of the brain autopsies is meaningful, maybe not so much from a neuroanatomical point of view as from a historical perspective. PMID:18182419

Vein, Alla A; Maat-Schieman, Marion L C

2008-02-01

86

Understanding Brain Injury and Neurodevelopmental Disabilities in the Preterm Infant: The Evolving Role of Advanced MRI  

PubMed Central

The high incidence of neurodevelopmental disability in premature infants requires continued efforts at understanding the underlying microstructural changes in the brain that cause this perturbation in normal development. Magnetic resonance imaging (MRI) methods offer great potential to fulfill this need. Serial MR imaging and the application of newer analysis techniques such as, diffusion tensor imaging (DTI), volumetric MR analysis, cortical surface analysis, functional connectivity (fcMRI) and diffusion tractography, provide important insights into the trajectory of brain development in the premature infant and the impact of injury on this developmental trajectory. While some of these imaging techniques are currently available in the research setting only, other measures such as DTI and brain metric measures can be used clinically. MR imaging also has enormous potential to be used as a surrogate, short-term outcome measure in clinical studies evaluating new therapeutic interventions of neuroprotection of the developing brain. In this article we review the current status of these advanced MR imaging techniques. PMID:20109973

Mathur, Amit M.; Neil, Jeffrey J.; Inder, Terrie E.

2010-01-01

87

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

88

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

89

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

90

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 ...

91

[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

92

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

93

Understanding the mind of a worm: hierarchical network structure underlying nervous system function in C. elegans  

Microsoft Academic Search

The nervous system of the nematode C. elegans provides a unique opportunity to understand how behavior (‘mind’) emerges from activity in the nervous system (‘brain’) of an organism. The hermaphrodite worm has only 302 neurons, all of whose connections (synaptic and gap junctional) are known. Recently, many of the functional circuits that make up its behavioral repertoire have begun to

Nivedita Chatterjee; Sitabhra Sinha

2007-01-01

94

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

95

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

96

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.

97

Chemical Biology for Understanding Matrix Metalloproteinase Function  

PubMed Central

The matrix metalloproteinase (MMP) family has long been associated with normal physiological processes such as embryonic implantation, tissue remodeling, organ development, and wound healing, as well as multiple aspects of cancer initiation and progression, osteoarthritis, inflammatory and vascular diseases, and neurodegenerative diseases. The development of chemically designed MMP probes has advanced our understanding of the roles of MMPs in disease in addition to shedding considerable light on the mechanisms of MMP action. The first generation of protease-activated agents has demonstrated proof of principle as well as providing impetus for in vivo applications. One common problem has been a lack of agent stability at nontargeted tissues and organs due to activation by multiple proteases. The present review considers how chemical biology has impacted the progress made in understanding the roles of MMPs in disease and the basic mechanisms of MMP action. PMID:22933318

Knapinska, Anna; Fields, Gregg B.

2013-01-01

98

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

99

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

100

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

101

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

102

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

103

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

104

Brain maturation and its relevance to understanding criminal culpability of juveniles  

Microsoft Academic Search

The purpose of this review is to summarize current understanding of the process of maturation in human brains during the juvenile\\u000a period to young adulthood. We describe the methods used in such investigations, and outline the main findings regarding the\\u000a course of brain development. There is much that we do not know about brain maturation, but there is congruence of

Ruben C. Gur

2005-01-01

105

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

106

The Brain: Understanding Neurobiology Through the Study of Addiction  

NSDL National Science Digital Library

They're finally here! The NIH Office of Science Education has recently launched Web versions of curriculum supplements from its series of "interactive teaching units that combine cutting-edge research discoveries from the National Institutes of Health with state-of-the-art instructional materials." "The Brain" is intended for grades 9-12. The supplement provides detailed, downloadable lesson plans, fantastic multimedia features, teachers' guides with downloadable worksheets, and loads of other excellent resources.

2008-09-24

107

Understanding Machine-learned Density Functionals  

E-print Network

Kernel ridge regression is used to approximate the kinetic energy of non-interacting fermions in a one-dimensional box as a functional of their density. The properties of different kernels and methods of cross-validation are explored, and highly accurate energies are achieved. Accurate {\\em constrained optimal densities} are found via a modified Euler-Lagrange constrained minimization of the total energy. A projected gradient descent algorithm is derived using local principal component analysis. Additionally, a sparse grid representation of the density can be used without degrading the performance of the methods. The implications for machine-learned density functional approximations are discussed.

Li, Li; Pelaschier, Isabelle M; Huang, Jessica; Niranjan, Uma-Naresh; Duncan, Paul; Rupp, Matthias; Müller, Klaus-Robert; Burke, Kieron

2014-01-01

108

Integration of visual and motor functional streams in the human brain.  

PubMed

A long-standing difficulty in brain research has been to disentangle how information flows across circuits composed by multiple local and distant cerebral areas. At the large-scale level, several brain imaging methods have contributed to the understanding of those circuits by capturing the covariance or coupling patterns of blood oxygen level-dependent (BOLD) activity between distributed brain regions. The hypothesis is that underlying information processes are closely associated to synchronized brain activity, and therefore to the functional connectivity structure of the human brain. In this study, we have used a recently developed method called stepwise functional connectivity analysis. Our results show that motor and visual connectivity merge in a multimodal integration network that links together perception, action and cognition in the human functional connectome. PMID:24699175

Sepulcre, Jorge

2014-05-01

109

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

110

ORIGINAL PAPER Understanding relationship between sequence and functional  

E-print Network

evolutionary biolo- gists to directly assess the relationships between evolutionary rates and functional variables. The usual strategy in such studies is to look for significant relationships between evolutionaryORIGINAL PAPER Understanding relationship between sequence and functional evolution in yeast

Yi, Soojin

111

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

112

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

113

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

114

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

115

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

116

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

117

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

118

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

119

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

120

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

121

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

122

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

123

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

124

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

125

Time-varying functional network information extracted from brief instances of spontaneous brain activity  

PubMed Central

Recent functional magnetic resonance imaging studies have shown that the brain is remarkably active even in the absence of overt behavior, and this activity occurs in spatial patterns that are reproducible across subjects and follow the brain’s established functional subdivision. Investigating the distribution of these spatial patterns is an active area of research with the goal of obtaining a better understanding of the neural networks underlying brain function. One intriguing aspect of spontaneous activity is an apparent nonstationarity, or variability of interaction between brain regions. It was recently proposed that spontaneous brain activity may be dominated by brief traces of activity, possibly originating from a neuronal avalanching phenomenon. Such traces may involve different subregions in a network at different times, potentially reflecting functionally relevant relationships that are not captured with conventional data analysis. To investigate this, we examined publicly available functional magnetic resonance imaging data with a dedicated analysis method and found indications that functional networks inferred from conventional correlation analysis may indeed be driven by activity at only a few critical time points. Subsequent analysis of the activity at these critical time points revealed multiple spatial patterns, each distinctly different from the established functional networks. The spatial distribution of these patterns suggests a potential functional relevance. PMID:23440216

Liu, Xiao; Duyn, Jeff H.

2013-01-01

126

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

127

Highlighting the Structure-Function Relationship of the Brain with the Ising Model and Graph Theory  

PubMed Central

With the advent of neuroimaging techniques, it becomes feasible to explore the structure-function relationships in the brain. When the brain is not involved in any cognitive task or stimulated by any external output, it preserves important activities which follow well-defined spatial distribution patterns. Understanding the self-organization of the brain from its anatomical structure, it has been recently suggested to model the observed functional pattern from the structure of white matter fiber bundles. Different models which study synchronization (e.g., the Kuramoto model) or global dynamics (e.g., the Ising model) have shown success in capturing fundamental properties of the brain. In particular, these models can explain the competition between modularity and specialization and the need for integration in the brain. Graphing the functional and structural brain organization supports the model and can also highlight the strategy used to process and organize large amount of information traveling between the different modules. How the flow of information can be prevented or partially destroyed in pathological states, like in severe brain injured patients with disorders of consciousness or by pharmacological induction like in anaesthesia, will also help us to better understand how global or integrated behavior can emerge from local and modular interactions.

Das, T. K.; Abeyasinghe, P. M.; Crone, J. S.; Sosnowski, A.; Laureys, S.; Owen, A. M.; Soddu, A.

2014-01-01

128

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

129

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

130

Use of Functional Magnetic Resonance Imaging (Blood Oxygenation Level-Dependent Imaging, Diffusion Tensor Imaging and Magnetic Resonance Spectroscopy) in Brain Development Research  

Microsoft Academic Search

The development of several new magnetic resonance imaging (MRI) techniques has facilitated serial observations of the developing human brain in utero. For example, the noninvasive technique of functional MRI, which is used to study brain anatomy, function and metabolism in both humans and animals, has already enhanced our understanding of brain development and behavior relations. Currently, three main kinds of

Fei Fei Yang; Shu Guang Yuan; David T. Yew

2008-01-01

131

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

132

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

133

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

134

Evidence from cognitive neuroscience for the role of graphical and algebraic representations in understanding function  

Microsoft Academic Search

Using traditional educational research methods, it is difficult to assess students’ understanding of mathematical concepts,\\u000a even though qualitative methods such as task observation and interviews provide some useful information. It has now become\\u000a possible to use functional magnetic resonance imaging (fMRI) to observe brain activity whilst students think about mathematics,\\u000a although much of this work has concentrated on number. In

Michael O. J. ThomasAnna; Anna J. Wilson; Michael C. CorballisVanessa; Vanessa K. Lim; Caroline Yoon

2010-01-01

135

Spatiotemporal brain imaging and modeling  

E-print Network

This thesis integrates hardware development, data analysis, and mathematical modeling to facilitate our understanding of brain cognition. Exploration of these brain mechanisms requires both structural and functional knowledge ...

Lin, Fa-Hsuan, 1972-

2004-01-01

136

Neurobiology of Cocaine-Induced Organic Brain Impairment: Contributions from Functional Neuroimaging  

Microsoft Academic Search

The present review is directed at imparting the current knowledge regarding functional neuroimaging as a tool for enhancing the understanding of cerebrophysiologic and neurobehavioral consequences of stimulant abuse. Stimulants like cocaine are capable of inducing clinically significant neurocognitive impairment through direct action on the brain, and indirectly through other organs that influence cerebral physiology. Neurochemical dysregulation including profound effects on

Tony L. Strickland; Bruce L. Miller; Arthur Kowell; Richard Stein

1998-01-01

137

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 ...

138

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

139

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

140

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

141

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

142

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

143

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

144

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

145

Mapping mental function to brain structure: How can cognitive neuroimaging succeed?  

PubMed Central

The goal of cognitive neuroscience is to identify the mapping between brain function and mental processing. In this paper, I examine the strategies that have been used to identify such mappings, and argue that they may be fundamentally unable to identify selective structure-function mappings. I argue that in order to understand the functional anatomy of mental processes, it will be necessary to move from the brain mapping strategies that the field has employed towards a search for selective associations. This will require a greater focus on the structure of cognitive processes, which can be achieved through the development of formal ontologies that describe the structure of mental processes. I outline the Cognitive Atlas project, which is developing such ontologies, and show how this knowledge could be used in conjunction with data mining approaches to more directly relate mental processes and brain function. PMID:25076977

Poldrack, Russell A.

2014-01-01

146

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

147

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

148

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

149

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

150

The role of tumor necrosis factor receptor superfamily members in mammalian brain development, function and homeostasis  

PubMed Central

Tumor necrosis factor receptor superfamily (TNFRSF) members were initially identified as immunological mediators, and are still commonly perceived as immunological molecules. However, our understanding of the diversity of TNFRSF members’ roles in mammalian physiology has grown significantly since the first discovery of TNFRp55 (TNFRSF1) in 1975. In particular, the last decade has provided evidence for important roles in brain development, function and the emergent field of neuronal homeostasis. Recent evidence suggests that TNFRSF members are expressed in an overlapping regulated pattern during neuronal development, participating in the regulation of neuronal expansion, growth, differentiation and regional pattern development. This review examines evidence for non-immunological roles of TNFRSF members in brain development, function and maintenance under normal physiological conditions. In addition, several aspects of brain function during inflammation will also be described, when illuminating and relevant to the non-immunological role of TNFRSF members. Finally, key questions in the field will be outlined. PMID:21861782

Twohig, Jason P.; Cuff, Simone M.; Yong, Audrey A.; Wang, Eddie C.Y.

2012-01-01

151

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

152

The Effectiveness of the Brain Based Teaching Approach in Enhancing Scientific Understanding of Newtonian Physics among Form Four Students  

ERIC Educational Resources Information Center

The aim of this study was to assess the effectiveness of Brain Based Teaching Approach in enhancing students' scientific understanding of Newtonian Physics in the context of Form Four Physics instruction. The technique was implemented based on the Brain Based Learning Principles developed by Caine & Caine (1991, 2003). This brain compatible…

Saleh, Salmiza

2012-01-01

153

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

154

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

155

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

156

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

157

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

158

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

159

Imaging functional and structural brain connectomics in attention-deficit/hyperactivity disorder.  

PubMed

Attention-deficit/hyperactivity disorder (ADHD) is one of the most common neurodevelopment disorders in childhood. Clinically, the core symptoms of this disorder include inattention, hyperactivity, and impulsivity. Previous studies have documented that these behavior deficits in ADHD children are associated with not only regional brain abnormalities but also changes in functional and structural connectivity among regions. In the past several years, our understanding of how ADHD affects the brain's connectivity has been greatly advanced by mapping topological alterations of large-scale brain networks (i.e., connectomes) using noninvasive neurophysiological and neuroimaging techniques (e.g., electroencephalograph, functional MRI, and diffusion MRI) in combination with graph theoretical approaches. In this review, we summarize the recent progresses of functional and structural brain connectomics in ADHD, focusing on graphic analysis of large-scale brain systems. Convergent evidence suggests that children with ADHD had abnormal small-world properties in both functional and structural brain networks characterized by higher local clustering and lower global integrity, suggesting a disorder-related shift of network topology toward regular configurations. Moreover, ADHD children showed the redistribution of regional nodes and connectivity involving the default-mode, attention, and sensorimotor systems. Importantly, these ADHD-associated alterations significantly correlated with behavior disturbances (e.g., inattention and hyperactivity/impulsivity symptoms) and exhibited differential patterns between clinical subtypes. Together, these connectome-based studies highlight brain network dysfunction in ADHD, thus opening up a new window into our understanding of the pathophysiological mechanisms of this disorder. These works might also have important implications on the development of imaging-based biomarkers for clinical diagnosis and treatment evaluation in ADHD. PMID:24705817

Cao, Miao; Shu, Ni; Cao, Qingjiu; Wang, Yufeng; He, Yong

2014-12-01

160

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

161

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

162

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

163

Brain glycogen-new perspectives on its metabolic function and regulation at the subcellular level.  

PubMed

Glycogen is a complex glucose polymer found in a variety of tissues, including brain, where it is localized primarily in astrocytes. The small quantity found in brain compared to e.g., liver has led to the understanding that brain glycogen is merely used during hypoglycemia or ischemia. In this review evidence is brought forward highlighting what has been an emerging understanding in brain energy metabolism: that glycogen is more than just a convenient way to store energy for use in emergencies-it is a highly dynamic molecule with versatile implications in brain function, i.e., synaptic activity and memory formation. In line with the great spatiotemporal complexity of the brain and thereof derived focus on the basis for ensuring the availability of the right amount of energy at the right time and place, we here encourage a closer look into the molecular and subcellular mechanisms underlying glycogen metabolism. Based on (1) the compartmentation of the interconnected second messenger pathways controlling glycogen metabolism (calcium and cAMP), (2) alterations in the subcellular location of glycogen-associated enzymes and proteins induced by the metabolic status and (3) a sequential component in the intermolecular mechanisms of glycogen metabolism, we suggest that glycogen metabolism in astrocytes is compartmentalized at the subcellular level. As a consequence, the meaning and importance of conventional terms used to describe glycogen metabolism (e.g., turnover) is challenged. Overall, this review represents an overview of contemporary knowledge about brain glycogen and its metabolism and function. However, it also has a sharp focus on what we do not know, which is perhaps even more important for the future quest of uncovering the roles of glycogen in brain physiology and pathology. PMID:22403540

Obel, Linea F; Müller, Margit S; Walls, Anne B; Sickmann, Helle M; Bak, Lasse K; Waagepetersen, Helle S; Schousboe, Arne

2012-01-01

164

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

165

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

166

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

167

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

168

The modulation of brain functional connectivity with manual acupuncture in healthy subjects: An electroencephalograph case study  

NASA Astrophysics Data System (ADS)

Manual acupuncture is widely used for pain relief and stress control. Previous studies on acupuncture have shown its modulatory effects on the functional connectivity associated with one or a few preselected brain regions. To investigate how manual acupuncture modulates the organization of functional networks at a whole-brain level, we acupuncture at ST36 of a right leg to obtain electroencephalograph (EEG) signals. By coherence estimation, we determine the synchronizations between all pairwise combinations of EEG channels in three acupuncture states. The resulting synchronization matrices are converted into functional networks by applying a threshold, and the clustering coefficients and path lengths are computed as a function of threshold. The results show that acupuncture can increase functional connections and synchronizations between different brain areas. For a wide range of thresholds, the clustering coefficient during acupuncture and post-acupuncture period is higher than that during the pre-acupuncture control period, whereas the characteristic path length is shorter. We provide further support for the presence of “small-world" network characteristics in functional networks by using acupuncture. These preliminary results highlight the beneficial modulations of functional connectivity by manual acupuncture, which could contribute to the understanding of the effects of acupuncture on the entire brain, as well as the neurophysiological mechanisms underlying acupuncture. Moreover, the proposed method may be a useful approach to the further investigation of the complexity of patterns of interrelations between EEG channels.

Yi, Guo-Sheng; Wang, Jiang; Han, Chun-Xiao; Deng, Bin; Wei, Xi-Le; Li, Nuo

2013-02-01

169

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

170

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

171

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

172

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

173

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

174

Spatial variability of functional brain networks in early-blind and sighted subjects.  

PubMed

To further the understanding how the human brain adapts to early-onset blindness, we searched in early-blind and normally-sighted subjects for functional brain networks showing the most and least spatial variabilities across subjects. We hypothesized that the functional networks compensating for early-onset blindness undergo cortical reorganization. To determine whether reorganization of functional networks affects spatial variability, we used functional magnetic resonance imaging to compare brain networks, derived by independent component analysis, of 7 early-blind and 7 sighted subjects while they rested or listened to an audio drama. In both conditions, the blind compared with sighted subjects showed more spatial variability in a bilateral parietal network (comprising the inferior parietal and angular gyri and precuneus) and in a bilateral auditory network (comprising the superior temporal gyri). In contrast, a vision-related left-hemisphere-lateralized occipital network (comprising the superior, middle and inferior occipital gyri, fusiform and lingual gyri, and the calcarine sulcus) was less variable in blind than sighted subjects. Another visual network and a tactile network were spatially more variable in the blind than sighted subjects in one condition. We contemplate whether our results on inter-subject spatial variability of brain networks are related to experience-dependent brain plasticity, and we suggest that auditory and parietal networks undergo a stronger experience-dependent reorganization in the early-blind than sighted subjects while the opposite is true for the vision-related occipital network. PMID:24680867

Boldt, Robert; Seppä, Mika; Malinen, Sanna; Tikka, Pia; Hari, Riitta; Carlson, Synnöve

2014-07-15

175

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

176

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

177

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

178

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

179

Coupling between neuronal activity and microcirculation: implications for functional brain imaging  

PubMed Central

In the neocortex, neurons with similar response properties are often clustered together in column-like structures, giving rise to what has become known as functional architecture—the mapping of various stimulus feature dimensions onto the cortical sheet. At least partially, we owe this finding to the availability of several functional brain imaging techniques, both post-mortem and in-vivo, which have become available over the last two generations, revolutionizing neuroscience by yielding information about the spatial organization of active neurons in the brain. Here, we focus on how our understanding of such functional architecture is linked to the development of those functional imaging methodologies, especially to those that image neuronal activity indirectly, through metabolic or haemodynamic signals, rather than directly through measurement of electrical activity. Some of those approaches allow exploring functional architecture at higher spatial resolution than others. In particular, optical imaging of intrinsic signals reaches the striking detail of ?50 ?m, and, together with other methodologies, it has allowed characterizing the metabolic and haemodynamic responses induced by sensory-evoked neuronal activity. Here, we review those findings about the spatio-temporal characteristics of neurovascular coupling and discuss their implications for functional brain imaging, including position emission tomography, and non-invasive neuroimaging techniques, such as funtional magnetic resonance imaging, applicable also to the human brain. PMID:19404475

Vanzetta, Ivo; Grinvald, Amiram

2008-01-01

180

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

181

Topological Organization of Functional Brain Networks in Healthy Children: Differences in Relation to Age, Sex, and Intelligence  

PubMed Central

Recent studies have demonstrated developmental changes of functional brain networks derived from functional connectivity using graph theoretical analysis, which has been rapidly translated to studies of brain network organization. However, little is known about sex- and IQ-related differences in the topological organization of functional brain networks during development. In this study, resting-state fMRI (rs-fMRI) was used to map the functional brain networks in 51 healthy children. We then investigated the effects of age, sex, and IQ on economic small-world properties and regional nodal properties of the functional brain networks. At a global level of whole networks, we found significant age-related increases in the small-worldness and local efficiency, significant higher values of the global efficiency in boys compared with girls, and no significant IQ-related difference. Age-related increases in the regional nodal properties were found predominately in the frontal brain regions, whereas the parietal, temporal, and occipital brain regions showed age-related decreases. Significant sex-related differences in the regional nodal properties were found in various brain regions, primarily related to the default mode, language, and vision systems. Positive correlations between IQ and the regional nodal properties were found in several brain regions related to the attention system, whereas negative correlations were found in various brain regions primarily involved in the default mode, emotion, and language systems. Together, our findings of the network topology of the functional brain networks in healthy children and its relationship with age, sex, and IQ bring new insights into the understanding of brain maturation and cognitive development during childhood and adolescence. PMID:23390528

Wu, Kai; Taki, Yasuyuki; Sato, Kazunori; Hashizume, Hiroshi; Sassa, Yuko; Takeuchi, Hikaru; Thyreau, Benjamin; He, Yong; Evans, Alan C.; Li, Xiaobo; Kawashima, Ryuta; Fukuda, Hiroshi

2013-01-01

182

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

183

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

184

Reduced functional brain connectivity prior to and after disease onset in Huntington's disease???  

PubMed Central

Background Huntington's disease (HD) is characterised by both regional and generalised neuronal cell loss in the brain. Investigating functional brain connectivity patterns in rest in HD has the potential to broaden the understanding of brain functionality in relation to disease progression. This study aims to establish whether brain connectivity during rest is different in premanifest and manifest HD as compared to controls. Methods At the Leiden University Medical Centre study site of the TRACK-HD study, 20 early HD patients (disease stages 1 and 2), 28 premanifest gene carriers and 28 healthy controls underwent 3 T MRI scanning. Standard and high-resolution T1-weighted images and a resting state fMRI scan were acquired. Using FSL, group differences in resting state connectivity were examined for eight networks of interest using a dual regression method. With a voxelwise correction for localised atrophy, group differences in functional connectivity were examined. Results Brain connectivity of the left middle frontal and pre-central gyrus, and right post central gyrus with the medial visual network was reduced in premanifest and manifest HD as compared to controls (0.05 > p > 0.0001). In manifest HD connectivity of numerous widespread brain regions with the default mode network and the executive control network were reduced (0.05 > p > 0.0001). Discussion Brain regions that show reduced intrinsic functional connectivity are present in premanifest gene carriers and to a much larger extent in manifest HD patients. These differences are present even when the potential influence of atrophy is taken into account. Resting state fMRI could potentially be used for early disease detection in the premanifest phase of HD and for monitoring of disease modifying compounds. PMID:24179791

Dumas, Eve M.; van den Bogaard, Simon J.A.; Hart, Ellen P.; Soeter, Roelof P.; van Buchem, Mark A.; van der Grond, Jeroen; Rombouts, Serge A.R.B.; Roos, Raymund A.C.

2013-01-01

185

Non-Invasive Brain Stimulation: Enhancing Motor and Cognitive Functions In Healthy Old Subjects  

PubMed Central

Healthy aging is accompanied by changes in cognitive and motor functions that result in impairment of activities of daily living. This process involves a number of modifications in the brain and is associated with metabolic, structural, and physiological changes; some of these serving as adaptive responses to the functional declines. Up to date there are no universally accepted strategies to ameliorate declining functions in this population. An essential basis to develop such strategies is a better understanding of neuroplastic changes during healthy aging. In this context, non-invasive brain stimulation techniques, such as transcranial direct current or transcranial magnetic stimulation, provide an attractive option to modulate cortical neuronal assemblies, even with subsequent changes in neuroplasticity. Thus, in the present review we discuss the use of these techniques as a tool to study underlying cortical mechanisms during healthy aging and as an interventional strategy to enhance declining functions and learning abilities in aged subjects. PMID:21151809

Zimerman, Maximo; Hummel, Friedhelm C.

2010-01-01

186

"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

187

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

188

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

189

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

190

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

191

Bovine brain ribonuclease is the functional homolog of human ribonuclease 1.  

PubMed

Mounting evidence suggests that human pancreatic ribonuclease (RNase 1) plays important roles in vivo, ranging from regulating blood clotting and inflammation to directly counteracting tumorigenic cells. Understanding these putative roles has been pursued with continual comparisons of human RNase 1 to bovine RNase A, an enzyme that appears to function primarily in the ruminant gut. Our results imply a different physiology for human RNase 1. We demonstrate distinct functional differences between human RNase 1 and bovine RNase A. Moreover, we characterize another RNase 1 homolog, bovine brain ribonuclease, and find pronounced similarities between that enzyme and human RNase 1. We report that human RNase 1 and bovine brain ribonuclease share high catalytic activity against double-stranded RNA substrates, a rare quality among ribonucleases. Both human RNase 1 and bovine brain RNase are readily endocytosed by mammalian cells, aided by tight interactions with cell surface glycans. Finally, we show that both human RNase 1 and bovine brain RNase are secreted from endothelial cells in a regulated manner, implying a potential role in vascular homeostasis. Our results suggest that brain ribonuclease, not RNase A, is the true bovine homolog of human RNase 1, and provide fundamental insight into the ancestral roles and functional adaptations of RNase 1 in mammals. PMID:25078100

Eller, Chelcie H; Lomax, Jo E; Raines, Ronald T

2014-09-19

192

Understanding the benefits of musical training: effects on oscillatory brain activity.  

PubMed

A number of studies suggest that musical training has benefits for other cognitive domains, such as language and mathematics, and studies of children and adults indicate structural as well as functional differences between the brains of musicians and nonmusicians. The induced gamma-band response has been associated with attentional, expectation, memory retrieval, and integration of top-down, bottom-up, and multisensory processes. Here we report data indicating that the induced gamma-band response to musical sounds is larger in adult musicians than in nonmusicians and that it develops in children after 1 year of musical training beginning at age 4.5 years, but not in children of this age who are not engaged in musical lessons. We conclude that musical training affects oscillatory networks in the brain associated with executive functions, and that superior executive functioning could enhance learning and performance in many cognitive domains. PMID:19673769

Trainor, Laurel J; Shahin, Antoine J; Roberts, Larry E

2009-07-01

193

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

194

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

195

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

196

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

197

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

198

Decreased in vitro mitochondrial function is associated with enhanced brain metabolism, blood flow, and memory in Surf1-deficient mice.  

PubMed

Recent studies have challenged the prevailing view that reduced mitochondrial function and increased oxidative stress are correlated with reduced longevity. Mice carrying a homozygous knockout (KO) of the Surf1 gene showed a significant decrease in mitochondrial electron transport chain Complex IV activity, yet displayed increased lifespan and reduced brain damage after excitotoxic insults. In the present study, we examined brain metabolism, brain hemodynamics, and memory of Surf1 KO mice using in vitro measures of mitochondrial function, in vivo neuroimaging, and behavioral testing. We show that decreased respiration and increased generation of hydrogen peroxide in isolated Surf1 KO brain mitochondria are associated with increased brain glucose metabolism, cerebral blood flow, and lactate levels, and with enhanced memory in Surf1 KO mice. These metabolic and functional changes in Surf1 KO brains were accompanied by higher levels of hypoxia-inducible factor 1 alpha, and by increases in the activated form of cyclic AMP response element-binding factor, which is integral to memory formation. These findings suggest that Surf1 deficiency-induced metabolic alterations may have positive effects on brain function. Exploring the relationship between mitochondrial activity, oxidative stress, and brain function will enhance our understanding of cognitive aging and of age-related neurologic disorders. PMID:23838831

Lin, Ai-Ling; Pulliam, Daniel A; Deepa, Sathyaseelan S; Halloran, Jonathan J; Hussong, Stacy A; Burbank, Raquel R; Bresnen, Andrew; Liu, Yuhong; Podlutskaya, Natalia; Soundararajan, Anuradha; Muir, Eric; Duong, Timothy Q; Bokov, Alex F; Viscomi, Carlo; Zeviani, Massimo; Richardson, Arlan G; Van Remmen, Holly; Fox, Peter T; Galvan, Veronica

2013-10-01

199

Decreased in vitro mitochondrial function is associated with enhanced brain metabolism, blood flow, and memory in Surf1-deficient mice  

PubMed Central

Recent studies have challenged the prevailing view that reduced mitochondrial function and increased oxidative stress are correlated with reduced longevity. Mice carrying a homozygous knockout (KO) of the Surf1 gene showed a significant decrease in mitochondrial electron transport chain Complex IV activity, yet displayed increased lifespan and reduced brain damage after excitotoxic insults. In the present study, we examined brain metabolism, brain hemodynamics, and memory of Surf1 KO mice using in vitro measures of mitochondrial function, in vivo neuroimaging, and behavioral testing. We show that decreased respiration and increased generation of hydrogen peroxide in isolated Surf1 KO brain mitochondria are associated with increased brain glucose metabolism, cerebral blood flow, and lactate levels, and with enhanced memory in Surf1 KO mice. These metabolic and functional changes in Surf1 KO brains were accompanied by higher levels of hypoxia-inducible factor 1 alpha, and by increases in the activated form of cyclic AMP response element-binding factor, which is integral to memory formation. These findings suggest that Surf1 deficiency-induced metabolic alterations may have positive effects on brain function. Exploring the relationship between mitochondrial activity, oxidative stress, and brain function will enhance our understanding of cognitive aging and of age-related neurologic disorders. PMID:23838831

Lin, Ai-Ling; Pulliam, Daniel A; Deepa, Sathyaseelan S; Halloran, Jonathan J; Hussong, Stacy A; Burbank, Raquel R; Bresnen, Andrew; Liu, Yuhong; Podlutskaya, Natalia; Soundararajan, Anuradha; Muir, Eric; Duong, Timothy Q; Bokov, Alex F; Viscomi, Carlo; Zeviani, Massimo; Richardson, Arlan G; Van Remmen, Holly; Fox, Peter T; Galvan, Veronica

2013-01-01

200

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

201

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

202

Turner syndrome and sexual differentiation of the brain: implications for understanding male-biased neurodevelopmental disorders.  

PubMed

Turner syndrome (TS) is one of the most common sex chromosome abnormalities. Affected individuals often show a unique pattern of cognitive strengths and weaknesses and are at increased risk for a number of other neurodevelopmental conditions, many of which are more common in typical males than typical females (e.g., autism and attention-deficit hyperactivity disorder). This phenotype may reflect gonadal steroid deficiency, haploinsufficiency of X chromosome genes, failure to express parentally imprinted genes, and the uncovering of X chromosome mutations. Understanding the contribution of these different mechanisms to outcome has the potential to improve clinical care for individuals with TS and to better our understanding of the differential vulnerability to and expression of neurodevelopmental disorders in males and females. In this paper, we review what is currently known about cognition and brain development in individuals with TS, discuss underlying mechanisms and their relevance to understanding male-biased neurodevelopmental conditions, and suggest directions for future research. PMID:21818630

Knickmeyer, Rebecca Christine; Davenport, Marsha

2011-12-01

203

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

204

Mining the brain metabolome to understand behavioural disruptions induced in mouse fed Hypochoeris radicata (L.), a neurotoxic plant for horse.  

PubMed

Mining the brain metabolome to understand behavioural disruptions induced in mouse fed Hypochoeris radicata (L.), a neurotoxic plant for horse. C57BL/6J mice orally exposed to 9% H. radicata (HR) are metabolically competent laboratory animals which can be used as model of Australian stringhalt, a neurological horse disease induced by HR ingestion. So, the present study was conducted to assess the brain metabolome and the behavioural performances of mice fed with a 9%-HR-based diet for 21 days. By the end of the period of exposure, mice were investigated for motor activity and coordination, anxiety level, learning and memory performances, social behaviour and rewarding properties of for the plant. Thus, the animals were sacrificed and the brain metabolome was studied using (1)H NMR spectroscopy. HR-exposed mice displayed a motor hyperactivity in several tasks, a less resignation in the forced swimming test, and paradigm place preference for the plant. A bootstrap-based regularized canonical analysis performed on merged behavioural and metabolic datasets showed a clear relationship in HR-treated mice between an increase in cerebral scyllo-inositol, an increased motor activity, and seemingly rewarding properties of HR. These results underlie the interest of such a dual approach to characterize functional end-points of a pathophysiological model of the Australian stringhalt in equine species. PMID:23811200

Domange, Céline; Schroeder, Henri; Violle, Nicolas; Peiffer, Julie; Canlet, Cécile; Paris, Alain; Priymenko, Nathalie

2013-09-01

205

The Postpartum Period of Pregnancy Worsens Brain Injury and Functional Outcome After Cerebellar Hemorrhage in Rats  

PubMed Central

Background Intracerebral hemorrhage (ICH) is one of the most common causes of maternal deaths related to the postpartum period. This is a devastating form of stroke for which there is no available treatment. Although premenopausal females tend to have better outcomes after most forms of brain injury, the effects of pregnancy and child birth lead to wide maternal physiological changes that may predispose the mother to an increased risk for stroke and greater initial injury. Methods Three different doses of collagenase were used to generate models of mild, moderate and severe cerebellar hemorrhage in postpartum female and male control rats. Brain water, blood-brain barrier rupture, hematoma size and neurological evaluations were performed 24 h later. Results Postpartum female rats had worsened brain water, blood-brain barrier rupture, hematoma size and neurological evaluations compared to their male counterparts. Conclusion The postpartum state reverses the cytoprotective effects commonly associated with the hormonal neuroprotection of (premenopausal) female gender, and leads to greater initial injury and worsened neurological function after cerebellar hemorrhage. This experimental model can be used for the study of future treatment strategies after postpartum brain hemorrhage, to gain a better understanding of the mechanistic basis for stroke in this important patient subpopulation. PMID:21725729

Lekic, Tim; Ostrowski, Robert P.; Suzuki, Hidenori; Manaenko, Anatol; Rolland, William; Fathali, Nancy; Tang, Jiping

2013-01-01

206

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

207

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

208

Executive function, self-regulation and attribution in acquired brain injury: A scoping review.  

PubMed

Impairments in executive function, self-regulation and attribution individually have been implicated in impairment in goal-directed behaviour, resulting in reduced participation in daily activities by individuals with brain injury. There is minimal literature that explicitly addresses the relationships among these constructs, how these may be affected by brain injury and the implications for rehabilitation. The objectives of this study were to determine what is known about the relationship between executive function, self-regulation and attribution, and to understand how these inter-relationships affect goal-directed behaviour in adults with acquired brain injury. A scoping review of the cognitive neuroscience, neuropsychology, rehabilitation, educational and social psychology literature from 1985 to 2011 was performed. The identified literature provided definitions of the constructs and insight into the relationships between them according to their neural underpinnings and theoretical models. These data also provided for the development of a new model illustrating the hypothesised relationships between constructs. This review and the model developed, suggest that attribution may play an important role in executive function and self-regulation. Rehabilitation interventions that address formulation of appropriate attributions should be considered in conjunction with those targeting self-regulation and executive function for individuals with brain injury. PMID:24032652

Hunt, Anne W; Turner, Gary R; Polatajko, Helene; Bottari, Carolina; Dawson, Deirdre R

2013-01-01

209

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

210

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

211

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

212

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

213

The Effect of Criticism on Functional Brain Connectivity and Associations with Neuroticism  

PubMed Central

Neuroticism is a robust personality trait that constitutes a risk factor for psychopathology, especially anxiety disorders and depression. High neurotic individuals tend to be more self-critical and are overly sensitive to criticism by others. Hence, we used a novel resting-state paradigm to investigate the effect of criticism on functional brain connectivity and associations with neuroticism. Forty-eight participants completed the NEO Personality Inventory Revised (NEO-PI-R) to assess neuroticism. Next, we recorded resting state functional magnetic resonance imaging (rsfMRI) during two sessions. We manipulated the second session before scanning by presenting three standardized critical remarks through headphones, in which the subject was urged to please lie still in the scanner. A seed-based functional connectivity method and subsequent clustering were used to analyse the resting state data. Based on the reviewed literature related to criticism, we selected brain regions associated with self-reflective processing and stress-regulation as regions of interest. The findings showed enhanced functional connectivity between the clustered seed regions and brain areas involved in emotion processing and social cognition during the processing of criticism. Concurrently, functional connectivity was reduced between these clusters and brain structures related to the default mode network and higher-order cognitive control. Furthermore, individuals scoring higher on neuroticism showed altered functional connectivity between the clustered seed regions and brain areas involved in the appraisal, expression and regulation of negative emotions. These results may suggest that the criticized person is attempting to understand the beliefs, perceptions and feelings of the critic in order to facilitate flexible and adaptive social behavior. Furthermore, multiple aspects of emotion processing were found to be affected in individuals scoring higher on neuroticism during the processing of criticism, which may increase their sensitivity to negative social-evaluation. PMID:23922755

Servaas, Michelle Nadine; Riese, Harriëtte; Renken, Remco Jan; Marsman, Jan-Bernard Cornelis; Lambregs, Johan; Ormel, Johan; Aleman, André

2013-01-01

214

The effect of criticism on functional brain connectivity and associations with neuroticism.  

PubMed

Neuroticism is a robust personality trait that constitutes a risk factor for psychopathology, especially anxiety disorders and depression. High neurotic individuals tend to be more self-critical and are overly sensitive to criticism by others. Hence, we used a novel resting-state paradigm to investigate the effect of criticism on functional brain connectivity and associations with neuroticism. Forty-eight participants completed the NEO Personality Inventory Revised (NEO-PI-R) to assess neuroticism. Next, we recorded resting state functional magnetic resonance imaging (rsfMRI) during two sessions. We manipulated the second session before scanning by presenting three standardized critical remarks through headphones, in which the subject was urged to please lie still in the scanner. A seed-based functional connectivity method and subsequent clustering were used to analyse the resting state data. Based on the reviewed literature related to criticism, we selected brain regions associated with self-reflective processing and stress-regulation as regions of interest. The findings showed enhanced functional connectivity between the clustered seed regions and brain areas involved in emotion processing and social cognition during the processing of criticism. Concurrently, functional connectivity was reduced between these clusters and brain structures related to the default mode network and higher-order cognitive control. Furthermore, individuals scoring higher on neuroticism showed altered functional connectivity between the clustered seed regions and brain areas involved in the appraisal, expression and regulation of negative emotions. These results may suggest that the criticized person is attempting to understand the beliefs, perceptions and feelings of the critic in order to facilitate flexible and adaptive social behavior. Furthermore, multiple aspects of emotion processing were found to be affected in individuals scoring higher on neuroticism during the processing of criticism, which may increase their sensitivity to negative social-evaluation. PMID:23922755

Servaas, Michelle Nadine; Riese, Harriëtte; Renken, Remco Jan; Marsman, Jan-Bernard Cornelis; Lambregs, Johan; Ormel, Johan; Aleman, André

2013-01-01

215

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

216

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

217

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

218

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

219

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

220

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

221

Data-Brain Modeling Based on Brain Informatics Methodology  

Microsoft Academic Search

This paper presents a case study on data-brain construction based on brain informatics (BI) methodology. The data-brain is a conceptual brain data model, which represents functional relationships among multiple human brain data sources, with respect to all major aspects and capabilities of human information processing system for systematic investigation and understanding of human intelligence. On one hand, developing such a

Jianhui Chen; Ning Zhong

2008-01-01

222

Contribution of brain imaging to the understanding of gait disorders in Alzheimer's disease: a systematic review.  

PubMed

Although gait disorders are common in Alzheimer's disease (AD), determining which brain structures and related lesions are specifically involved is a goal yet to be reached. Our objective was to systematically review all published data that examined associations between gait disorders and brain imaging in AD. Of 486 selected studies, 4 observational studies met the selection criteria. The number of participants ranged from 2 to 61 community dwellers (29%-100% female) with prodromal or dementia-stage AD. Quantitative gait disorders (ie, slower gait velocity explained by shorter stride length) were associated with white matter lesions, mainly in the medial frontal lobes and basal ganglia. The nigrostriatal dopamine system was unaffected. Qualitative gait disorders (ie, higher stride length variability) correlated with lower hippocampal volume and function. Gait disorders in AD could be explained by a high burden of age-related subcortical hyperintensities on the frontal-subcortical circuits (nonspecific) together with hippocampal atrophy and hypometabolism (specific). PMID:22930697

Annweiler, Cédric; Beauchet, Olivier; Celle, Sébastien; Roche, Frédéric; Annweiler, Thierry; Allali, Gilles; Bartha, Robert; Montero-Odasso, Manuel

2012-09-01

223

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

224

Do you know what I mean? Brain oscillations and the understanding of communicative intentions.  

PubMed

Pointing gesture allows children to communicate their intentions before the acquisition of language. In particular, two main purposes seem to underlie the gesture: to request a desired object (imperative pointing) or to share attention on that object (declarative pointing). Since the imperative pointing has an instrumental goal and the declarative has an interpersonal one, only the latter gesture is thought to signal the infant's awareness of the communicative partner as a mental agent. The present study examined the neural responses of adult subjects with the aim to test the hypothesis that declarative rather than imperative pointing reflects mentalizing skills. Fourteen subjects were measured in a magnetoencephalographic environment including four conditions, based on the goal of the pointing - imperative or declarative - and the role of the subject - sender or receiver of pointing. Time-frequency modulations of brain activity in each condition (declarative production and comprehension, imperative production and comprehension) were analyzed. Both low beta and high beta power were stronger during declarative than imperative condition in anterior cingulated cortex and right posterior superior temporal sulcus, respectively. Furthermore, high gamma activity was higher in right temporo-parietal junction during the sender than receiving condition. This suggests that communicative pointing modulated brain regions previously described in neuroimaging research as linked to social cognitive skills and that declarative pointing is more capable of eliciting that activation than imperative. Our results contribute to the understanding of the roles of brain rhythm dynamics in social cognition, thus supporting neural research on that topic during developmental both in typical and atypical conditions, such as autism spectrum disorder. In particular, the identification of relevant regions in a mature brain may stimulate a future work on the developmental changes of neural activation in the same regions. PMID:24550813

Brunetti, Marcella; Zappasodi, Filippo; Marzetti, Laura; Perrucci, Mauro Gianni; Cirillo, Simona; Romani, Gian Luca; Pizzella, Vittorio; Aureli, Tiziana

2014-01-01

225

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

226

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

227

Understanding international differences in terminology for delirium and other types of acute brain dysfunction in critically ill patients  

Microsoft Academic Search

Background  Delirium (acute brain dysfunction) is a potentially life threatening disturbance in brain function that frequently occurs\\u000a in critically ill patients. While this area of brain dysfunction in critical care is rapidly advancing, striking limitations\\u000a in use of terminology related to delirium internationally are hindering cross-talk and collaborative research. In the English\\u000a literature, synonyms of delirium such as the Intensive Care

A. Morandi; P. Pandharipande; M. Trabucchi; R. Rozzini; G. Mistraletti; A. C. Trompeo; C. Gregoretti; L. Gattinoni; M. V. Ranieri; L. Brochard; D. Annane; C. Putensen; U. Guenther; P. Fuentes; E. Tobar; A. R. Anzueto; A. Esteban; Y. Skrobik; J. I. F. Salluh; M. Soares; C. Granja; A. Stubhaug; S. E. de Rooij; E. Wesley Ely

2008-01-01

228

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

229

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

230

Understanding the development and function of T follicular helper cells  

PubMed Central

A fundamental function of T helper (Th) cells is to regulate B-cell proliferation and immunoglobulin class switching, especially in the germinal centers. Th1 and Th2 lineages of CD4+ T cells have long been considered to play an essential role in helping B cells by promoting the production immunoglobulin G2a (IgG2a) and IgG1/IgE, respectively. Recently, it has become clear that a subset CD4+ T cells, named T follicular helper (Tfh) cells, is critical to B-cell response induction. In this review, we summarize the latest advances in our understanding of the regulation of Tfh cell differentiation, the relationship of Tfh cells to other CD4+ T-cell lineages, and the role of Tfh cells in health and disease. PMID:20383172

Nurieva, Roza I; Chung, Yeonseok

2010-01-01

231

How Should Educational Neuroscience Conceptualise the Relation between Cognition and Brain Function? Mathematical Reasoning as a Network Process  

ERIC Educational Resources Information Center

Background: There is increasing interest in applying neuroscience findings to topics in education. Purpose: This application requires a proper conceptualization of the relation between cognition and brain function. This paper considers two such conceptualizations. The area focus understands each cognitive competency as the product of one (and only…

Varma, Sashank; Schwartz, Daniel L.

2008-01-01

232

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

233

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

234

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

235

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

236

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

237

Functional brain networks: great expectations, hard times and the big leap forward.  

PubMed

Many physical and biological systems can be studied using complex network theory, a new statistical physics understanding of graph theory. The recent application of complex network theory to the study of functional brain networks has generated great enthusiasm as it allows addressing hitherto non-standard issues in the field, such as efficiency of brain functioning or vulnerability to damage. However, in spite of its high degree of generality, the theory was originally designed to describe systems profoundly different from the brain. We discuss some important caveats in the wholesale application of existing tools and concepts to a field they were not originally designed to describe. At the same time, we argue that complex network theory has not yet been taken full advantage of, as many of its important aspects are yet to make their appearance in the neuroscience literature. Finally, we propose that, rather than simply borrowing from an existing theory, functional neural networks can inspire a fundamental reformulation of complex network theory, to account for its exquisitely complex functioning mode. PMID:25180303

Papo, David; Zanin, Massimiliano; Pineda-Pardo, José Angel; Boccaletti, Stefano; Buldú, Javier M

2014-10-01

238

Towards a mechanistic understanding of lipodystrophy and seipin functions.  

PubMed

CGL (Congenital generalized lipodystrophy) is a genetic disorder characterized by near complete loss of adipose tissue along with increased ectopic fat storage in other organs including liver and muscle. Of the four CGL types, BSCL2 (Berardinelli-Seip Congenital lipodystrophy type 2), resulting from mutations in the BSCL2/seipin gene, exhibits the most severe lipodystrophic phenotype with loss of both metabolic and mechanical adipose depots. The majority of Seipin mutations cause C-terminal truncations, along with a handful of point mutations. Seipin localizes to the ER and is composed of a conserved region including a luminal loop and two transmembrane domains, plus cytosolic N- and C-termini. Animal models deficient in seipin recapitulate the human lipodystrophic phenotype. Cells isolated from seipin knockout mouse models also exhibit impaired adipogenesis. Mechanistically, seipin appears to function as a scaffolding protein to bring together interacting partners essential for lipid metabolism and LD (lipid droplet) formation during adipocyte development. Moreover, cell line and genetic studies indicate that seipin functions in a cell-autonomous manner. Here we will provide a brief overview of the genetic association of the CGLs, and focus on the current understanding of differential contributions of distinct seipin domains to lipid storage and adipogenesis. We will also discuss the roles of seipin-interacting partners, including lipin 1 and 14-3-3?, in mediating seipin-dependent regulation of cellular pathways such as actin cytoskeletal remodelling. PMID:25195639

Wee, Kenneth; Yang, Wulin; Sugii, Shigeki; Han, Weiping

2014-01-01

239

Towards a mechanistic understanding of lipodystrophy and seipin functions  

PubMed Central

CGL (Congenital generalized lipodystrophy) is a genetic disorder characterized by near complete loss of adipose tissue along with increased ectopic fat storage in other organs including liver and muscle. Of the four CGL types, BSCL2 (Berardinelli–Seip Congenital lipodystrophy type 2), resulting from mutations in the BSCL2/seipin gene, exhibits the most severe lipodystrophic phenotype with loss of both metabolic and mechanical adipose depots. The majority of Seipin mutations cause C-terminal truncations, along with a handful of point mutations. Seipin localizes to the ER and is composed of a conserved region including a luminal loop and two transmembrane domains, plus cytosolic N- and C-termini. Animal models deficient in seipin recapitulate the human lipodystrophic phenotype. Cells isolated from seipin knockout mouse models also exhibit impaired adipogenesis. Mechanistically, seipin appears to function as a scaffolding protein to bring together interacting partners essential for lipid metabolism and LD (lipid droplet) formation during adipocyte development. Moreover, cell line and genetic studies indicate that seipin functions in a cell-autonomous manner. Here we will provide a brief overview of the genetic association of the CGLs, and focus on the current understanding of differential contributions of distinct seipin domains to lipid storage and adipogenesis. We will also discuss the roles of seipin-interacting partners, including lipin 1 and 14-3-3?, in mediating seipin-dependent regulation of cellular pathways such as actin cytoskeletal remodelling. PMID:25195639

Wee, Kenneth; Yang, Wulin; Sugii, Shigeki; Han, Weiping

2014-01-01

240

Cytokines for Psychologists: Implications of Bidirectional Immune-to-Brain Communication for Understanding Behavior, Mood, and Cognition  

Microsoft Academic Search

The brain and immune system form a bidirectional communication network in which the immune system operates as a diffuse sense organ, informing the brain about events in the body. This allows the activation of immune cells to produce physiological, behavioral, affective, and cognitive changes that are collectively called sickness, which function to promote recuperation. Fight–flight evolved later and coopted this

Steven F. Maier; Linda R. Watkins

1998-01-01

241

The challenge to remove diffuse low-grade gliomas while preserving brain functions.  

PubMed

WHO grade II glioma, i.e. diffuse low-grade glioma, is a pre-malignant tumour, usually revealed by seizures in young patients with a normal life. This tumour has a constant growth, and will inescapably become anaplastic. Surgical resection significantly increases the overall survival by delaying the malignant transformation. Thus, the dilemma is to perform early surgery in order to optimise the extent of resection (and thus the median survival) by removing smaller tumours while preserving the quality of life. To this end, the new concept proposed in this review is to achieve surgical resection according to functional and not to oncological boundaries. In other words, the principle is to first understand the cerebral anatomo-functional organisation at the individual level (because of a major inter-individual variability), with the aim of resecting a part of the brain invaded by a diffuse chronic disease, on the condition nonetheless that this part of the brain can be functionally compensated-i.e. with no consequences on the quality of life. To this end, in addition to the preoperative functional neuroimaging and the intraoperative electrical cortical mapping in awake patients, it is also crucial to map both horizontal cortico-cortical connectivity (long-distance association fibres) as well as vertical cortico-subcortical connectivity (projection fibres), with the aim to preserve the networks underlying the minimal common core of the brain. Interestingly, this "hodotopical" workframe, based on the study of both cortical epicentres and subcortical pathways, opens the door to mechanisms of functional reshaping. These recent technical and conceptual advances in the hodotopical and plastic view of brain processing have allowed a dramatic improvement of the benefit-to-risk ratio of surgery, concerning both oncological and functional outcomes. In summary, it is time to move towards "functional neurooncology" and "preventive neurosurgery" in low-grade gliomas. Stronger interactions with fundamental neurosciences should be developed, in order (1) to build updated models of cognition and brain plasticity; (2) to elaborate biomathematical models of low-grade glioma growth and migration; (3) to study in silico the dynamic interactions between the natural course of this disease and the adaptative behaviour of its host (the brain), with the goal to adapt the best individualised therapeutic strategy. PMID:22278663

Duffau, Hugues

2012-04-01

242

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

243

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

244

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

245

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

246

Invited commentary: understanding brain mechanisms of pain processing in adolescents' non-suicidal self-injury.  

PubMed

Whereas non-suicidal self injury (NSSI) is reported in 13-23% of adolescents and is an increasingly studied topic, there has been little investigation into the pathophysiology behind self-injury. This commentary examines recent research into pain and emotional distress to discuss implications for the manner we should understand, research, and treat NSSI in the future. Research indicates that adolescents may be particularly vulnerable to NSSI behaviors due to neurodevelopmental changes in the processing of distress and pain. Additionally, emotional distress and physical pain neural pathways may have been altered in these individuals, leading to the development of NSSI behaviors during adolescence when changes in ongoing brain development may lead to further emotional dysregulation and poor impulse control. Further studies that directly characterize the relationship between emotional distress and physical pain in adolescence, as well as the neural differences between self-injurers and non-self-injurers, are needed. PMID:19830534

Ballard, Elizabeth; Bosk, Abigail; Pao, Maryland

2010-04-01

247

The prairie vole: an emerging model organism for understanding the social brain  

PubMed Central

Unlike most mammalian species, the prairie vole is highly affiliative, forms enduring social bonds between mates, and displays biparental behavior. Over two decades of research in this species has enhanced our understanding of the neurobiological basis not only of monogamy, social attachment and nurturing behaviors, but also other aspects of social cognition. Because social cognitive deficits are hallmarks of many psychiatric disorders, discoveries made in prairie voles may direct novel treatment strategies for disorders such as autism spectrum disorder and schizophrenia. With the ongoing development of molecular, genetic and genomic tools for this species, prairie voles will likely maintain their current trajectory becoming an unprecedented model organism for basic and translational research focusing on the biology of the social brain. PMID:20005580

McGraw, Lisa A.; Young, Larry J.

2009-01-01

248

Cracking neural circuits in a tiny brain: new approaches for understanding the neural circuitry of Drosophila  

PubMed Central

Genetic screens in Drosophila have identified many genes involved in neural development and function. However, until recently, it has been impossible to monitor neural signals in Drosophila central neurons, and it has been difficult to make specific perturbations to central neural circuits. This has changed in the past few years with the development of new tools for measuring and manipulating neural activity in the fly. Here we review how these new tools enable novel conceptual approaches to “cracking circuits” in this important model organism. We discuss recent studies aimed at defining the cognitive demands on the fly brain, identifying the cellular components of specific neural circuits, mapping functional connectivity in those circuits, and defining causal relationships between neural activity and behavior. PMID:18775572

Olsen, Shawn R.; Wilson, Rachel I.

2010-01-01

249

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

250

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

251

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

252

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

253

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

254

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

255

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

256

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

257

Epileptic seizures induce structural and functional alterations on brain tissue membranes.  

PubMed

Epilepsy is characterized by disruption of balance between cerebral excitation and inhibition, leading to recurrent and unprovoked convulsions. Studies are still underway to understand mechanisms lying epileptic seizures with the aim of improving treatment strategies. In this context, the research on brain tissue membranes gains importance for generation of epileptic activities. In order to provide additional information for this field, we have investigated the effects of pentylenetetrazol-induced and audiogenetically susceptible epileptic seizures on structure, content and function of rat brain membrane components using Fourier transform infrared (FT-IR) spectroscopy. The findings have shown that both two types of epileptic seizures stimulate the variations in the molecular organization of membrane lipids, which have potential to influence the structures in connection with functions of membrane proteins. Moreover, less fluid lipid structure and a decline in content of lipids obtained from the ratio of CH3 asym/lipid, CH2 asym/lipid, CO/lipid, and olefinicCH/lipid and the areas of the PO2 symmetric and asymmetric modes were observed. Moreover, based on IR data the changes in the conformation of proteins were predicted by neural network (NN) analysis, and displayed as an increase in random coil despite a decrease in beta sheet. Depending on spectral parameters, we have successfully differentiated treated samples from the control by principal component analysis (PCA) and cluster analysis. In summary, FT-IR spectroscopy may offer promising attempt to identify compositional, structural and functional alterations in brain tissue membranes resulting from epileptic activities. PMID:25194682

Turker, Sevgi; Severcan, Mete; Ilbay, Gul; Severcan, Feride

2014-12-01

258

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.

259

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...

260

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

261

[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

262

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

263

"Biological rhythms, higher brain function, and behavior: gaps, opportunities and challenges"  

PubMed Central

Increasing evidence suggests that disrupted temporal organization impairs behavior, cognition, and affect; further, disruption of circadian clock genes impairs sleep/wake cycle and social rhythms which may be implicated in mental disorders. Despite this strong evidence, a gap in understanding the neural mechanisms of this interaction obscures whether biological rhythms disturbances are the underlying causes or merely symptoms of these diseases. Here, we review current understanding, emerging concepts, gaps and opportunities pertinent to: (1) the neurobiology of the interactions between circadian oscillators and the neural circuits subserving higher brain function and behaviors of relevance to mental health, (2) the most promising approaches to determine how biological rhythms regulate brain function and behavior under normal and pathological conditions, (3) gaps and challenges to advancing knowledge on the link between disrupted circadian rhythms/sleep and psychiatric disorders, and (4) novel strategies for translation of basic science discoveries in circadian biology to clinical settings to define risk, prevent or delay onset of mental illnesses, design diagnostic tools and propose new therapeutic strategies. The review is organized around five themes pertinent to: (1) the impact of molecular clocks on physiology and behavior, (2) interactions between circadian signals and cognitive functions, (3) the interface of circadian rhythms with sleep (4) a clinical perspective on the relationship between circadian rhythm abnormalities and affective disorders, and (5) pre-clinical models of circadian rhythm abnormalities and mood disorders. PMID:19766673

Benca, Ruth; Duncan, Marilyn J.; Frank, Ellen; McClung, Colleen; Nelson, Randy J.; Vicentic, Aleksandra

2009-01-01

264

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

265

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

266

Mapping Functional Brain Activation Using [14C]-Iodoantipyrine in Male Serotonin Transporter Knockout Mice  

PubMed Central

Background Serotonin transporter knockout mice have been a powerful tool in understanding the role played by the serotonin transporter in modulating physiological function and behavior. However, little work has examined brain function in this mouse model. We tested the hypothesis that male knockout mice show exaggerated limbic activation during exposure to an emotional stressor, similar to human subjects with genetically reduced transcription of the serotonin transporter. Methodology/Principal Findings Functional brain mapping using [14C]-iodoantipyrine was performed during recall of a fear conditioned tone. Regional cerebral blood flow was analyzed by statistical parametric mapping from autoradiographs of the three-dimensionally reconstructed brains. During recall, knockout mice compared to wild-type mice showed increased freezing, increased regional cerebral blood flow of the amygdala, insula, and barrel field somatosensory cortex, decreased regional cerebral blood flow of the ventral hippocampus, and conditioning-dependent alterations in regional cerebral blood flow in the medial prefrontal cortex (prelimbic, infralimbic, and cingulate). Anxiety tests relying on sensorimotor exploration showed a small (open field) or paradoxical effect (marble burying) of loss of the serotonin transporter on anxiety behavior, which may reflect known abnormalities in the knockout animal's sensory system. Experiments evaluating whisker function showed that knockout mice displayed impaired whisker sensation in the spontaneous gap crossing task and appetitive gap cross training. Conclusions This study is the first to demonstrate altered functional activation in the serotonin transporter knockout mice of critical nodes of the fear conditioning circuit. Alterations in whisker sensation and functional activation of barrel field somatosensory cortex extend earlier reports of barrel field abnormalities, which may confound behavioral measures relying on sensorimotor exploration. PMID:21886833

Pang, Raina D.; Wang, Zhuo; Klosinski, Lauren P.; Guo, Yumei; Herman, David H.; Celikel, Tansu; Dong, Hong Wei; Holschneider, Daniel P.

2011-01-01

267

Abnormalities of functional brain networks in pathological gambling: a graph-theoretical approach  

PubMed Central

Functional neuroimaging studies of pathological gambling (PG) demonstrate alterations in frontal and subcortical regions of the mesolimbic reward system. However, most investigations were performed using tasks involving reward processing or executive functions. Little is known about brain network abnormalities during task-free resting state in PG. In the present study, graph-theoretical methods were used to investigate network properties of resting state functional magnetic resonance imaging data in PG. We compared 19 patients with PG to 19 healthy controls (HCs) using the Graph Analysis Toolbox (GAT). None of the examined global metrics differed between groups. At the nodal level, pathological gambler showed a reduced clustering coefficient in the left paracingulate cortex and the left juxtapositional lobe (supplementary motor area, SMA), reduced local efficiency in the left SMA, as well as an increased node betweenness for the left and right paracingulate cortex and the left SMA. At an uncorrected threshold level, the node betweenness in the left inferior frontal gyrus was decreased and increased in the caudate. Additionally, increased functional connectivity between fronto-striatal regions and within frontal regions has also been found for the gambling patients. These findings suggest that regions associated with the reward system demonstrate reduced segregation but enhanced integration while regions associated with executive functions demonstrate reduced integration. The present study makes evident that PG is also associated with abnormalities in the topological network structure of the brain during rest. Since alterations in PG cannot be explained by direct effects of abused substances on the brain, these findings will be of relevance for understanding functional connectivity in other addictive disorders. PMID:24098282

Tschernegg, Melanie; Crone, Julia S.; Eigenberger, Tina; Schwartenbeck, Philipp; Fauth-Buhler, Mira; Lemenager, Tagrid; Mann, Karl; Thon, Natasha; Wurst, Friedrich M.; Kronbichler, Martin

2013-01-01

268

Developing high-performance cross-functional teams: Understanding motivations, functional loyalties, and teaming fundamentals  

SciTech Connect

Teamwork is the key to the future of effective technology management. Today`s technologies and markets have become too complex for individuals to work alone. Global competition, limited resources, cost consciousness, and time pressures have forced organizations and project managers to encourage teamwork. Many of these teams will be cross-functional teams that can draw on a multitude of talents and knowledge. To develop high-performing cross-functional teams, managers must understand motivations, functional loyalties, and the different backgrounds of the individual team members. To develop a better understanding of these issues, managers can learn from experience and from literature on teams and teaming concepts. When studying the literature to learn about cross-functional teaming, managers will find many good theoretical concepts, but when put into practice, these concepts have varying effects. This issue of varying effectiveness is what drives the research for this paper. The teaming concepts were studied to confirm or modify current understanding. The literature was compared with a {open_quotes}ground truth{close_quotes}, a survey of the reality of teaming practices, to examine the teaming concepts that the literature finds to be critical to the success of teams. These results are compared to existing teams to determine if such techniques apply in real-world cases.

Miller, M.A.

1996-08-01

269

Age-related changes in topological patterns of large-scale brain functional networks during memory encoding and recognition.  

PubMed

In this study we used functional magnetic resonance imaging to investigate age-related changes in large-scale brain functional networks during memory encoding and recognition in 12 younger and 16 older adults. For each participant, functional brain networks were constructed by computing temporal correlation matrices of 90 brain regions and analyzed using graph theoretical approaches. We found the age-related changes mainly in the long-range connections with widespread reductions associated with aging in the fronto-temporal and temporo-parietal regions, and a few age-related increases in the posterior parietal regions. Graph theoretical analysis revealed that the older adults had longer path lengths linking different regions in the functional brain networks as compared to the younger adults. Further analysis indicated that the increases in shortest path length in the networks were combined with the loss of long-range connections. Finally, we showed that for older adults, frontal areas played reduced roles in the network (reduced regional centrality), whereas several default-mode regions played increased roles relative to younger subjects (increased regional centrality). Together, our results suggest that normal aging is associated with disruption of large-scale brain systems during the performance of memory tasks, which provides novel insights into the understanding of age-related decline in multiple cognitive functions. PMID:20093190

Wang, Liang; Li, Yanfang; Metzak, Paul; He, Yong; Woodward, Todd S

2010-04-15

270

Bottom up modeling of the connectome: linking structure and function in the resting brain and their changes in aging.  

PubMed

With the increasing availability of advanced imaging technologies, we are entering a new era of neuroscience. Detailed descriptions of the complex brain network enable us to map out a structural connectome, characterize it with graph theoretical methods, and compare it to the functional networks with increasing detail. To link these two aspects and understand how dynamics and structure interact to form functional brain networks in task and in the resting state, we use theoretical models. The advantage of using theoretical models is that by recreating functional connectivity and time series explicitly from structure and pre-defined dynamics, we can extract critical mechanisms by linking structure and function in ways not directly accessible in the real brain. Recently, resting-state models with varying local dynamics have reproduced empirical functional connectivity patterns, and given support to the view that the brain works at a critical point at the edge of a bifurcation of the system. Here, we present an overview of a modeling approach of the resting brain network and give an application of a neural mass model in the study of complexity changes in aging. PMID:23629050

Nakagawa, Tristan T; Jirsa, Viktor K; Spiegler, Andreas; McIntosh, Anthony R; Deco, Gustavo

2013-10-15

271

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

272

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

273

New understanding of adolescent brain development; relevance to transitional healthcare for young people with long term conditions  

PubMed Central

Summary Whether or not adolescence should be treated as a special period, there is now no doubt that the brain changes much during adolescence. From an evolutionary perspective, the idea of an under developed brain which is not fit for purpose until adulthood is illogical. Rather, the adolescent brain is likely to support the challenges specific to that period of life. New imaging techniques show unequivocal, striking changes in the white and gray matter which take place between 11 and 25 years of age. There is increased connectivity between brain regions, and increased dopaminergic activity in the pre-frontal cortices, the striatum and limbic system and the pathways linking them. The brain is dynamic, with some areas developing faster and becoming more dominant until other areas catch up. Plausible mechanisms can be postulated for linking these changes to the cognitive and behavioural features of adolescence. The changing brain may lead to abrupt behavioural change with the attendant risks; but it also produces a brain which is flexible and able to respond quickly and imaginatively. Society sets a context and environment that allows adolescent exuberance and creativity to be bounded and explored in relative safety. Whilst these changes apply to all young people, in healthcare settings they are especially relevant to young people with long term conditions in the context of their transition to young adult life; such young people need to learn to manage their health condition and their health care providers need to understand how to facilitate this. PMID:23986559

Colver, Allan; Longwell, Sarah

2014-01-01

274

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

275

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

276

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

277

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

278

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

279

Using microarrays and functional genomics to understand and target cancer  

Microsoft Academic Search

Conclusion  In our work microarrays are of importance for screening the whole genome to sort out important genes and also for constructing\\u000a pathways systems for the understanding of the links between genes.\\u000a \\u000a Our studies demonstrate the potential clinical usefulness of microarrays for the classification of patients and for understanding\\u000a cancer biology and identifying new drug targets.

Torben F. Ørntoft

2005-01-01

280

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

281

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

282

Brain Imaging: Applications in Psychiatry.  

ERIC Educational Resources Information Center

Discusses various brain imaging techniques, including computed tomography, magnetic resonance imaging, measurement of regional cerebral blood flow, single photo emission tomography, and position emission tomography. Describes the uses of these techniques in helping to understand brain functioning. (TW)

Andreasen, Nancy C.

1988-01-01

283

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

284

Correspondence between structure and function in the human brain at rest  

PubMed Central

To further understanding of basic and complex cognitive functions, previous connectome research has identified functional and structural connections of the human brain. Functional connectivity is often measured by using resting-state functional magnetic resonance imaging (rs-fMRI) and is generally interpreted as an indirect measure of neuronal activity. Gray matter (GM) primarily consists of neuronal and glia cell bodies; therefore, it is surprising that the majority of connectome research has excluded GM measures. Therefore, we propose that by exploring where GM corresponds to function would aid in the understanding of both structural and functional connectivity and in turn the human connectome. A cohort of 603 healthy participants underwent structural and functional scanning on the same 3 T scanner at the Mind Research Network. To investigate the spatial correspondence between structure and function, spatial independent component analysis (ICA) was applied separately to both GM density (GMD) maps and to rs-fMRI data. ICA of GM delineates structural components based on the covariation of GMD regions among subjects. For the rs-fMRI data, ICA identified spatial patterns with common temporal features. These decomposed structural and functional components were then compared by spatial correlation. Basal ganglia components exhibited the highest structural to resting-state functional spatial correlation (r = 0.59). Cortical components generally show correspondence between a single structural component and several resting-state functional components. We also studied relationships between the weights of different structural components and identified the precuneus as a hub in GMD structural network correlations. In addition, we analyzed relationships between component weights, age, and gender; concluding that age has a significant effect on structural components. PMID:22470337

Segall, Judith M.; Allen, Elena A.; Jung, Rex E.; Erhardt, Erik B.; Arja, Sunil K.; Kiehl, Kent; Calhoun, Vince D.

2012-01-01

285

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

286

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

287

Potential Use of MEG to Understand Abnormalities in Auditory Function in Clinical Populations  

PubMed Central

Magnetoencephalography (MEG) provides a direct, non-invasive view of neural activity with millisecond temporal precision. Recent developments in MEG analysis allow for improved source localization and mapping of connectivity between brain regions, expanding the possibilities for using MEG as a diagnostic tool. In this paper, we first describe inverse imaging methods (e.g., minimum-norm estimation) and functional connectivity measures, and how they can provide insights into cortical processing. We then offer a perspective on how these techniques could be used to understand and evaluate auditory pathologies that often manifest during development. Here we focus specifically on how MEG inverse imaging, by providing anatomically based interpretation of neural activity, may allow us to test which aspects of cortical processing play a role in (central) auditory processing disorder [(C)APD]. Appropriately combining auditory paradigms with MEG analysis could eventually prove useful for a hypothesis-driven understanding and diagnosis of (C)APD or other disorders, as well as the evaluation of the effectiveness of intervention strategies. PMID:24659963

Larson, Eric; Lee, Adrian K. C.

2014-01-01

288

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

289

Reorganization of Functional Brain Maps After Exercise Training: Importance of Cerebellar-Thalamic-Cortical Pathway  

PubMed Central

Exercise training (ET) causes functional and morphologic changes in normal and injured brain. While studies have examined effects of short-term (same day) training on functional brain activation, less work has evaluated effects of long-term training, in particular treadmill running. An improved understanding is relevant as changes in neural reorganization typically require days to weeks, and treadmill training is a component of many neurorehabilitation programs. Adult, male rats (n=10) trained to run for 40 min/day, 5 days/week on a Rotarod treadmill at 11.5 cm/sec, while control animals (n=10) walked for 1 minute/day at 1.2 cm/sec. Six weeks later, [14C]-iodoantipyrine was injected intravenously during treadmill walking. Regional cerebral blood flow-related tissue radioactivity was quantified by autoradiography and analyzed in the three-dimensionally reconstructed brain by statistical parametric mapping. Exercised compared to nonexercised rats demonstrated increased influence of the cerebellar-thalamic-cortical (CbTC) circuit, with relative increases in perfusion in deep cerebellar nuclei (medial, interposed, lateral), thalamus (ventrolateral, midline, intralaminar), and paravermis, but with decreases in the vermis. In the basal ganglia-thalamic-cortical circuit significant decreases were noted in sensorimotor cortex and striatum, with associated increases in the globus pallidus. Additional significant changes were noted in the ventral pallidum, superior colliculus, dentate gyrus (increases), and red nucleus (decreases). Following ET, the new dynamic equilibrium of the brain is characterized by increases in the efficiency of neural processing (sensorimotor cortex, striatum, vermis) and an increased influence of the CbTC circuit. Cerebral regions demonstrating changes in neural activation may point to alternate circuits, which may be mobilized during neurorehabilitation. PMID:17964551

Holschneider, DP; Yang, J; Guo, Y; Maarek, J-M I

2009-01-01

290

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

291

Understanding the function of CD1-restricted T cells  

Microsoft Academic Search

CD1 molecules bind foreign lipid antigens as they survey the endosomal compartments of infected antigen-presenting cells. Unlike T cells that recognize CD1-restricted foreign lipids, CD1-restricted T cells that are self-antigen–reactive function as 'auto-effectors' that are rapidly stimulated to carry out helper and effector functions upon interaction with CD1-expressing antigen-presenting cells. The functional distinctions between subsets of CD1-restricted T cells, and

Michael S Vincent; Jenny E Gumperz; Michael B Brenner

2003-01-01

292

ay 1 Mysteries of Brain : Come and `learn about the brain'. Have you wondered, "What is our brain like?" "How do we sense things around us?" and "How do we react to our environment?"  

E-print Network

of Brain : Come and `learn about the brain'. Have you wondered, "What is our brain like?" "How do we sense about `neuron' as a basic unit of the brain, structure of the brain, functions closely associated with brain lobes and hemispheres and understanding the nervous system Special Focus: Brain Hemispheres

Narayanan, H.

293

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

294

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

295

Exercise Challenge in Gulf War Illness Reveals Two Subgroups with Altered Brain Structure and Function  

PubMed Central

Nearly 30% of the approximately 700,000 military personnel who served in Operation Desert Storm (1990–1991) have developed Gulf War Illness, a condition that presents with symptoms such as cognitive impairment, autonomic dysfunction, debilitating fatigue and chronic widespread pain that implicate the central nervous system. A hallmark complaint of subjects with Gulf War Illness is post-exertional malaise; defined as an exacerbation of symptoms following physical and/or mental effort. To study the causal relationship between exercise, the brain, and changes in symptoms, 28 Gulf War veterans and 10 controls completed an fMRI scan before and after two exercise stress tests to investigate serial changes in pain, autonomic function, and working memory. Exercise induced two clinical Gulf War Illness subgroups. One subgroup presented with orthostatic tachycardia (n?=?10). This phenotype correlated with brainstem atrophy, baseline working memory compensation in the cerebellar vermis, and subsequent loss of compensation after exercise. The other subgroup developed exercise induced hyperalgesia (n?=?18) that was associated with cortical atrophy and baseline working memory compensation in the basal ganglia. Alterations in cognition, brain structure, and symptoms were absent in controls. Our novel findings may provide an understanding of the relationship between the brain and post-exertional malaise in Gulf War Illness. PMID:23798990

Rayhan, Rakib U.; Stevens, Benson W.; Raksit, Megna P.; Ripple, Joshua A.; Timbol, Christian R.; Adewuyi, Oluwatoyin; VanMeter, John W.; Baraniuk, James N.

2013-01-01

296

Exercise challenge in Gulf War Illness reveals two subgroups with altered brain structure and function.  

PubMed

Nearly 30% of the approximately 700,000 military personnel who served in Operation Desert Storm (1990-1991) have developed Gulf War Illness, a condition that presents with symptoms such as cognitive impairment, autonomic dysfunction, debilitating fatigue and chronic widespread pain that implicate the central nervous system. A hallmark complaint of subjects with Gulf War Illness is post-exertional malaise; defined as an exacerbation of symptoms following physical and/or mental effort. To study the causal relationship between exercise, the brain, and changes in symptoms, 28 Gulf War veterans and 10 controls completed an fMRI scan before and after two exercise stress tests to investigate serial changes in pain, autonomic function, and working memory. Exercise induced two clinical Gulf War Illness subgroups. One subgroup presented with orthostatic tachycardia (n?=?10). This phenotype correlated with brainstem atrophy, baseline working memory compensation in the cerebellar vermis, and subsequent loss of compensation after exercise. The other subgroup developed exercise induced hyperalgesia (n?=?18) that was associated with cortical atrophy and baseline working memory compensation in the basal ganglia. Alterations in cognition, brain structure, and symptoms were absent in controls. Our novel findings may provide an understanding of the relationship between the brain and post-exertional malaise in Gulf War Illness. PMID:23798990

Rayhan, Rakib U; Stevens, Benson W; Raksit, Megna P; Ripple, Joshua A; Timbol, Christian R; Adewuyi, Oluwatoyin; VanMeter, John W; Baraniuk, James N

2013-01-01

297

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

298

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

299

The Brain and Consciousness: Sources of Information for Understanding Adult Learning.  

ERIC Educational Resources Information Center

Reviews current knowledge of the brain in the areas of neurobiology, aging, and consciousness as conceived by different cultures. Derives learning principles that take into account the brain's plasticity, ability to respond to learning throughout life, and the involvement of emotional and sensory experience. (Contains 27 references.) (SK)

Hill, Lilian H.

2001-01-01

300

MODELING INTRACRANIAL FLUID FLOWS AND VOLUMES DURING TRAUMATIC BRAIN INJURY TO BETTER UNDERSTAND PRESSURE  

E-print Network

treatment options for elevated ICP during traumatic brain injury (TBI). The model uses fluid volumes mechanisms that are activated during TBI. Keywords--intracranial pressure (ICP), traumatic brain injury (TBI), dynamic modeling, therapeutic modeling. I. INTRODUCTION Elevated ICP associated with TBI is a major

301

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

302

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

303

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

304

Functional coupling of simultaneous electrical and metabolic activity in the human brain  

Microsoft Academic Search

The relationships between brain electrical and metabolic activity are being uncovered currently in animal models using invasive methods; however, in the human brain this relationship remains not well understood. In particular, the relationship between noninvasive measurements of electrical activity and metabolism remains largely undefined. To understand better these relations, cerebral activity was measured simultaneously with electroencephalography (EEG) and positron emission

Terrence R. Oakes; Diego A. Pizzagalli; Andrew M. Hendrick; Katherine A. Horras; Christine L. Larson; Heather C. Abercrombie; Stacey M. Schaefer; John V. Koger; Richard J. Davidson

2004-01-01

305

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

306

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

307

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

308

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

309

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

310

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

311

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

312

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

313

Understanding and assessing the motivations of volunteers: a functional approach.  

PubMed

The authors applied functionalist theory to the question of the motivations underlying volunteerism, hypothesized 6 functions potentially served by volunteerism, and designed an instrument to assess these functions (Volunteer Functions Inventory; VFI). Exploratory and confirmatory factor analyses on diverse samples yielded factor solutions consistent with functionalist theorizing; each VFI motivation, loaded on a single factor, possessed substantial internal consistency and temporal stability and correlated only modestly with other VFI motivations (Studies 1, 2, and 3). Evidence for predictive validity is provided by a laboratory study in which VFI motivations predicted the persuasive appeal of messages better when message and motivation were matched than mismatched (Study 4), and by field studies in which the extent to which volunteers' experiences matched their motivations predicted satisfaction (Study 5) and future intentions (Study 6). Theoretical and practical implications are discussed. PMID:9654757

Clary, E G; Snyder, M; Ridge, R D; Copeland, J; Stukas, A A; Haugen, J; Miene, P

1998-06-01

314

Students' Understanding of the General Notion of a Function of Two Variables  

ERIC Educational Resources Information Center

In this study we analyze students' understanding of two-variable function; in particular we consider their understanding of domain, possible arbitrary nature of function assignment, uniqueness of function image, and range. We use APOS theory and semiotic representation theory as a theoretical framework to analyze data obtained from interviews with…

Martinez-Planell, Rafael; Trigueros Gaisman, Maria

2012-01-01

315

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, ...

316

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

317

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

318

High School Students' Understanding of the Function Concept  

ERIC Educational Resources Information Center

This paper is a study of part of the Algebra Project's program for underrepresented high school students from the lowest quartile of academic achievement, social and economic status. The study focuses on students' learning the concept of function. The curriculum and pedagogy are part of an innovative, experimental approach designed and implemented…

Dubinsky, Ed; Wilson, Robin T.

2013-01-01

319

Functional brain networks and abnormal connectivity in the movement disorders  

PubMed Central

Clinical manifestations of movement disorders, such as Parkinson’s disease (PD) and dystonia, arise from neurophysiological changes within the cortico-striato-pallidothalamocortical (CSPTC) and cerebello-thalamo-cortical (CbTC) circuits. Neuroimaging techniques that probe connectivity within these circuits can be used to understand how these disorders develop as well as identify potential targets for medical and surgical therapies. Indeed, network analysis of 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET) has identified abnormal metabolic networks associated with the cardinal motor symptoms of PD, such as akinesia and tremor, as well as PD-related cognitive dysfunction. More recent task-based and resting state functional magnetic resonance imaging studies have reproduced several of the altered connectivity patterns identified in these abnormal PD-related networks. A similar network analysis approach in dystonia revealed abnormal disease related metabolic patterns in both manifesting and non-manifesting carriers of dystonia mutations. Other multimodal imaging approaches using magnetic resonance diffusion tensor imaging in patients with primary genetic dystonia suggest abnormal connectivity within the CbTC circuits mediate the clinical manifestations of this inherited neurodevelopmental disorder. Ongoing developments in functional imaging and future studies in early patients are likely to enhance our understanding of these movement disorders and guide novel targets for future therapies. PMID:22206967

Poston, Kathleen L.; Eidelberg, David

2012-01-01

320

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

321

Big thoughts in small brains? Dogs as a model for understanding human social cognition.  

PubMed

In this review we argued that dogs can provide a good model for both the evolution of human social-cognitive abilities and studying the underlying neural and genetic structures of these behavioural features. The key difference between the present and other approaches for modelling human social evolution lies in the assumption that there is a large overlap between the human and dog behaviour complex because during their evolution in close contact with human groups dogs evolved functionally similar social skills. Thus the parallel investigation of the human and dog behaviour complex widens our possibility for understanding human social cognition because it allows the modelling of the interaction between various components in contrast to other models which are often restricted to modelling a single aspect of human social cognitive skills. PMID:17496805

Miklósi, Adám; Topál, József; Csányi, Vilmos

2007-03-26

322

Inflaming the Brain: CRPS a model disease to understand Neuroimmune interactions in Chronic Pain  

PubMed Central

We review current concepts in CRPS from a neuroimaging perspective and point out topics and potential mechanisms that are suitable to be investigated in the next step towards understanding the pathophysiology of CRPS. We have outlined functional aspects of the syndrome, from initiating lesion via inflammatory mechanisms to CNS change and associated sickness behavior, with current evidence for up-regulation of immunological factors in CRPS, neuroimaging of systemic inflammation, and neuroimaging findings in CRPS. The initiation, maintenances and CNS targets implicated in CRPS and in the neuro-inflammatory reflex are discussed in terms of CRPS symptoms and recent preclinical studies. Potential avenues for investigating CRPS with PET and fMRI are described, along with roles of inflammation, treatment and behavior in CRPS. It is our hope that this outline will provoke discussion and promote further empirical studies on the interactions between central and peripheral inflammatory pathways manifest in CRPS. PMID:23188523

Linnman, C; Becerra, L; Borsook, D

2012-01-01

323

Neuromodulation of Brain States  

PubMed Central

Switches between different behavioral states of the animal are associated with prominent changes in global brain activity, between sleep and wakefulness or from inattentive to vigilant states. What mechanisms control brain states, and what are the functions of the different states? Here we summarize current understanding of the key neural circuits involved in regulating brain states, with a particular emphasis on the subcortical neuromodulatory systems. At the functional level, arousal and attention can greatly enhance sensory processing, whereas sleep and quiet wakefulness may facilitate learning and memory. Several new techniques developed over the past decade promise great advances in our understanding of the neural control and function of different brain states. PMID:23040816

Lee, Seung-Hee; Dan, Yang

2013-01-01

324

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

325

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

326

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

327

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

328

Researchers' big data crisis; understanding design and functionality  

Microsoft Academic Search

The Communications Web site, http:\\/\\/cacm.acm.org, features more than a dozen bloggers in the BLOG@CACM community. In each issue of Communications, we'll publish selected posts or excerpts.twitterFollow us on Twitter at http:\\/\\/twitter.com\\/blogCACMhttp:\\/\\/cacm.acm.org\\/blogs\\/blog-cacmMichael Stonebraker issues a call to arms about research groups' data-management problems. Jason Hong discusses the nature of functionality with respect to design.

Michael Stonebraker; Jason Hong

2012-01-01

329

Brain plasticity and functionality explored by nonlinear optical microscopy  

NASA Astrophysics Data System (ADS)

In combination with fluorescent protein (XFP) expression techniques, two-photon microscopy has become an indispensable tool to image cortical plasticity in living mice. In parallel to its application in imaging, multi-photon absorption has also been used as a tool for the dissection of single neurites with submicrometric precision without causing any visible collateral damage to the surrounding neuronal structures. In this work, multi-photon nanosurgery is applied to dissect single climbing fibers expressing GFP in the cerebellar cortex. The morphological consequences are then characterized with time lapse 3-dimensional two-photon imaging over a period of minutes to days after the procedure. Preliminary investigations show that the laser induced fiber dissection recalls a regenerative process in the fiber itself over a period of days. These results show the possibility of this innovative technique to investigate regenerative processes in adult brain. In parallel with imaging and manipulation technique, non-linear microscopy offers the opportunity to optically record electrical activity in intact neuronal networks. In this work, we combined the advantages of second-harmonic generation (SHG) with a random access (RA) excitation scheme to realize a new microscope (RASH) capable of optically recording fast membrane potential events occurring in a wide-field of view. The RASH microscope, in combination with bulk loading of tissue with FM4-64 dye, was used to simultaneously record electrical activity from clusters of Purkinje cells in acute cerebellar slices. Complex spikes, both synchronous and asynchronous, were optically recorded simultaneously across a given population of neurons. Spontaneous electrical activity was also monitored simultaneously in pairs of neurons, where action potentials were recorded without averaging across trials. These results show the strength of this technique in describing the temporal dynamics of neuronal assemblies, opening promising perspectives in understanding the computations of neuronal networks.

Sacconi, L.; Allegra, L.; Buffelli, M.; Cesare, P.; D'Angelo, E.; Gandolfi, D.; Grasselli, G.; Lotti, J.; Mapelli, J.; Strata, P.; Pavone, F. S.

2010-02-01

330

NIH Researchers Use Brain Imaging to Understand Genetic Link between Parkinson's and a Rare Disease  

MedlinePLUS

... associated parkinsonism: a positron emission tomography study of dopamine synthesis and regional cerebral blood flow Brain , July ... PET scan showing how the areas with decreased dopamine synthesis (yellow) in patients with Gaucher disease and ...

331

Understanding Alcoholism Through microRNA Signatures in Brains of Human Alcoholics  

PubMed Central

Advances in the fields of genomics and genetics in the last decade have identified a large number of genes that can potentially influence alcohol-drinking behavior in humans as well as animal models. Consequently, the task of identifying efficient molecular targets that could be used to develop effective therapeutics against the disease has become increasingly daunting. One of the reasons for this is the fact that each of the many alcohol-responsive genes only contributes a small effect to the overall mechanism and disease phenotype, as is characteristic of complex traits. Current research trends are hence shifting toward the analysis of gene networks rather than emphasizing individual genes. The discovery of microRNAs and their mechanisms of action on regulation of transcript level and protein translation have made evident the utility of these small non-coding RNA molecules that act as central coordinators of multiple cross-communicating cellular pathways. Cells exploit the fact that a single microRNA can target hundreds of mRNA transcripts and that a single mRNA transcript can be simultaneously targeted by distinct microRNAs, to ensure fine-tuned and/or redundant control over a large number of cellular functions. By the same token, we can use these properties of microRNAs to develop novel, targeted strategies to combat complex disorders. In this review, we will focus on recent discoveries of microRNA signatures in brain of human alcoholics supporting the hypothesis that changes in gene expression and regulation by microRNAs are responsible for long-term neuroadaptations occurring during development of alcoholism. We also discuss insights into the potential modulation of epigenetic regulators by a subset of microRNAs. Taken together, microRNA activity may be controlling many of the cellular mechanisms already known to be involved in the development of alcoholism, and suggests potential targets for the development of novel therapeutic interventions. PMID:22514554

Nunez, Yury O.; Mayfield, R. Dayne

2012-01-01

332

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

333

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

334

Deconstructing the brain's moral network: dissociable functionality between the temporoparietal junction and ventro-medial prefrontal cortex  

PubMed Central

Research has illustrated that the brain regions implicated in moral cognition comprise a robust and broadly distributed network. However, understanding how these brain regions interact and give rise to the complex interplay of cognitive processes underpinning human moral cognition is still in its infancy. We used functional magnetic resonance imaging to examine patterns of activation for ‘difficult’ and ‘easy’ moral decisions relative to matched non-moral comparators. This revealed an activation pattern consistent with a relative functional double dissociation between the temporoparietal junction (TPJ) and ventro-medial prefrontal cortex (vmPFC). Difficult moral decisions activated bilateral TPJ and deactivated the vmPFC and OFC. In contrast, easy moral decisions revealed patterns of activation in the vmPFC and deactivation in bilateral TPJ and dorsolateral PFC. Together these results suggest that moral cognition is a dynamic process implemented by a distributed network that involves interacting, yet functionally dissociable networks. PMID:23322890

Mobbs, Dean; Dalgleish, Tim

2014-01-01

335

MSFD2A is critical for the formation and function of the blood brain barrier  

PubMed Central

The central nervous system (CNS) requires a tightly controlled environment free of toxins and pathogens to provide the proper chemical composition for neural function. This environment is maintained by the ‘blood brain barrier’ (BBB), which is composed of blood vessels whose endothelial cells display specialized tight junctions and extremely low rates of transcellular vesicular transport (transcytosis)1–3. In concert with pericytes and astrocytes, this unique brain endothelial physiological barrier seals the CNS and controls substance influx and efflux4–6. While BBB breakdown has recently been associated with initiation and perpetuation of various neurological disorders, an intact BBB is a major obstacle for drug delivery to the CNS7–10. A limited understanding of the molecular mechanisms that control BBB formation has hindered our ability to manipulate the BBB in disease and therapy. Here, we identify mechanisms governing the establishment of a functional BBB. First, using a novel embryonic tracer injection method, we demonstrate spatiotemporal developmental profiles of BBB functionality and find that the mouse BBB becomes functional at embryonic day 15.5 (E15.5). We then screen for BBB-specific genes expressed during BBB formation, and find that major facilitator super family domain containing 2a (Mfsd2a) is selectively expressed in BBB-containing blood vessels in the CNS. Genetic ablation of Mfsd2a results in a leaky BBB from embryonic periods through adulthood, while maintaining the normal patterning of vascular networks. Electron microscopy examination reveals a dramatic increase in CNS endothelial cell vesicular transcytosis in Mfsd2a?/? mice, without obvious tight junction defects. Finally we show that MFSD2A endothelial expression is regulated by pericytes to facilitate BBB integrity. These findings identify MFSD2A as a key regulator of BBB function that may act by suppressing transcytosis in CNS endothelial cells. Further our findings may aid in efforts to develop therapeutic approaches for CNS drug delivery. PMID:24828040

Ben-Zvi, Ayal; Lacoste, Baptiste; Kur, Esther; Andreone, Benjamin J.; Mayshar, Yoav; Yan, Han; Gu, Chenghua

2014-01-01

336

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

337

In Vivo Imaging of Brain Development: Technologies, Models, Applications, and Impact on Understanding the Etiology of Mental Retardation  

Microsoft Academic Search

\\u000a Development of the mammalian brain proceeds in a precisely controlled sequence of cell divisions, migration, differentiation,\\u000a and synaptogenesis. It is a process of precise dynamic assembly, and time lapse in vivo imaging of these processes is fundamental\\u000a for the multidisciplinary endeavor to merge and understand the morphological, physiological, and regulatory processes of neurogenesis.\\u000a \\u000a \\u000a Modern optical and non-optical imaging technologies enable

Vicko Gluncic

338

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

339

Understanding Interpersonal Function in Psychiatric Illness Through Multiplayer Economic Games  

PubMed Central

Interpersonal factors play significant roles in the onset, maintenance, and remission of psychiatric conditions. In the current major diagnostic classification systems for psychiatric disorders, some conditions are defined by the presence of impairments in social interaction or maintaining interpersonal relationships; these include autism, social phobia, and the personality disorders. Other psychopathologies confer significant difficulties in the social domain, including major depression, posttraumatic stress disorder, and psychotic disorders. Still other mental health conditions, including substance abuse and eating disorders, seem to be exacerbated or triggered in part by the influence of social peers. For each of these and other psychiatric conditions, the extent and quality of social support is a strong determinant of outcome such that high social support predicts symptom improvement and remission. Despite the central role of interpersonal factors in psychiatric illness, the neurobiology of social impairments remains largely unexplored, in part due to difficulties eliciting and quantifying interpersonal processes in a parametric manner. Recent advances in functional neuroimaging, combined with multiplayer exchange games drawn from behavioral economics, and computational/quantitative approaches more generally, provide a fitting paradigm within which to study interpersonal function and dysfunction in psychiatric conditions. In this review, we outline the importance of interpersonal factors in psychiatric illness and discuss ways in which neuroeconomics provides a tractable framework within which to examine the neurobiology of social dysfunction. PMID:22579510

2014-01-01

340

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

341

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

342

Understanding myosin functions in plants: are we there yet?  

PubMed

Myosins are motor proteins that drive movements along actin filaments and have long been assumed to be responsible for cytoplasmic streaming in plant cells. This conjecture is now firmly established by genetic analysis in the reference species, Arabidopsis thaliana. This work and similar approaches in the moss, Physcomitrella patens, also established that myosin-driven movements are necessary for cell growth and polarity, organelle distribution and shape, and actin organization and dynamics. Identification of a mechanistic link between intracellular movements and cell expansion has proven more challenging, not the least because of the high level of apparent genetic redundancy among myosin family members. Recent progress in the creation of functional complementation constructs and identification of interaction partners promises a way out of this dilemma. PMID:24446546

Madison, Stephanie L; Nebenführ, Andreas

2013-12-01

343

Brain death and tissue and organ transplantation: the understanding of medical students  

PubMed Central

Objective To evaluate the level of knowledge of medical students about transplantation and brain death. Methods An anonymous self-administered questionnaire answered by medical students from the first through the sixth year that was based on information from the Associação Brasileira de Transplante de Órgãos e Tecidos, the Registro Brasileiro de Transplantes and the resolution that defines the criteria for brain death. Results Of the 677 medical students asked, 310 (45.8%) agreed to answer the questionnaire. In total, 22 (7.0%) subjects were excluded. Of the students who participated, 41.3% reported having already attended a class on organ transplantation and 33% on brain death; 9.7% felt able to diagnose brain death (p<0.01); only 66.8% indicated the kidney as the most transplanted solid organ in Brazil. Conclusion The level of knowledge of medical students at this institution regarding brain death and transplantation is limited, which may be the result of an inadequate approach during medical school. PMID:24553508

dos Reis, Flavio Pola; Gomes, Bruno Henrique Pinto; Pimenta, Lucas Lopes; Etzel, Arnaldo

2013-01-01

344

The contribution of brain sub-cortical loops in the expression and acquisition of action understanding abilities?  

PubMed Central

Research on action understanding in cognitive neuroscience has led to the identification of a wide “action understanding network” mainly encompassing parietal and premotor cortical areas. Within this cortical network mirror neurons are critically involved implementing a neural mechanism according to which, during action understanding, observed actions are reflected in the motor patterns for the same actions of the observer. We suggest that focusing only on cortical areas and processes could be too restrictive to explain important facets of action understanding regarding, for example, the influence of the observer's motor experience, the multiple levels at which an observed action can be understood, and the acquisition of action understanding ability. In this respect, we propose that aside from the cortical action understanding network, sub-cortical processes pivoting on cerebellar and basal ganglia cortical loops could crucially support both the expression and the acquisition of action understanding abilities. Within the paper we will discuss how this extended view can overcome some limitations of the “pure” cortical perspective, supporting new theoretical predictions on the brain mechanisms underlying action understanding that could be tested by future empirical investigations. PMID:23911926

Caligiore, Daniele; Pezzulo, Giovanni; Miall, R. Chris; Baldassarre, Gianluca

2013-01-01

345

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

346

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 ...

347

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 ...

348

Neuropsychobiological Evidence for the Functional Presence and Expression of Cannabinoid CB2 Receptors in the Brain  

Microsoft Academic Search

For over a decade, until recently, it was thought that marijuana acts by activating brain-type cannabinoid receptors called CB1, and that a second type called CB2 cannabinoid receptor was found only in peripheral tissues. Neuronal CB2 receptors in the brain had been controversial. We reported the discovery and functional presence of CB2 cannabinoid receptors in the mammalian brain that may

Emmanuel S. Onaivi

2006-01-01

349

Genetic Determinants of Cognitive Function and Age-Related Brain Changes  

Microsoft Academic Search

The brain is by far the most complicated structure of the human being, and its malfunction is\\u000acharacterized by various degrees and types of morbidity. Several brain functions deteriorate with\\u000aincreasing age during life. Cognitive decline and age-related brain pathology are common in the\\u000aelderly, but these changes may also become manifest early in life and preceding the onset of

M. Schuur

2010-01-01

350

Baseline Cardiovascular Risk Predicts Subsequent Changes in Resting Brain Function  

PubMed Central

Background and Purpose The Framingham Heart Study group cardiovascular disease risk profile (FCRP) score was used to assess the relationship between baseline cardiovascular risk and subsequent changes in resting state cerebral blood flow (CBF) in cognitively normal older participants from the Baltimore Longitudinal Study of Aging (BLSA). Methods 97 cognitively normal participants underwent annual resting-state PET scans at baseline and over a period of up to 8 years (mean interval 7.4 years). Images quantifying voxel-wise longitudinal rates of CBF change were calculated and used to examine the relationship between baseline FCRP score and changes over time in regional CBF. Individual components of the FCRP score (age, cholesterol, blood pressure, smoking status and type-II diabetes) were also correlated with changes in regional CBF to examine the independent contributions of each component to the overall pattern of change. Results Higher baseline FCRP scores were associated with accelerated longitudinal decline in CBF in orbitofrontal, medial frontal/anterior cingulate, insular, precuneus and brainstem regions. Of the components that make up the FCRP score, higher diastolic blood pressure and diabetes were associated independently with greater decline in the medial frontal/anterior cingulate and insular regions, respectively. Conclusions Baseline cardiovascular risk factors are associated with greater rates of decline in resting state regional brain function. The regions showing accelerated decline participate in higher order cognitive processes and are also vulnerable to age-related neuropathology. These results, in conjunction with other studies, encourage early treatment of cardiovascular risk factors in older individuals. PMID:22492519

Beason-Held, LL; Thambisetty, M; Deib, G; Sojkova, J; Landman, BA; Zonderman, AB; Ferrucci, L; Kraut, MA; Resnick, SM

2012-01-01

351

Towards understanding the biological function of hopanoids (Invited)  

NASA Astrophysics Data System (ADS)

Rhodopseudomonas palustris TIE-1 expresses bacterial hopanoid lipids that are structurally similar and evolutionarily related to eukaryotic sterols. The genome of R. palustris TIE-1 contains two copies of the hpnN gene (hpnN1 and hpnN2) that are orthologs of genes encoding eukaryotic sterol and lipid transporters. Hopanoid localization to the outer membrane was found to be dependent upon hpnN1. Since the cell cycle of R. palustris TIE-1 is obligately bimodal with each cell division resulting in the generation of one mother and one swarmer cell, evidence was obtained that hopanoids where specifically localized to the outer membrane of mother cells. The sequestration of hopanoids to the mother cells was also disrupted by the deletion of the hpnN1 gene. Mutants lacking the hopanoid transporters were able to grow normally at 30 °C but showed decreased growth at 38 °C. The hopanoid transporter mutant formed cellular filaments when grown at elevated temperature. Because sedimentary steranes and hopanes comprise some of the earliest evidence for the emergence of distinct bacteria and eukaryotic phyla, a better appreciation of the function of hopanoids will improve our ability to interpret the evolution of life on Earth.

Doughty, D. M.; Hunter, R.; Summons, R. E.; Newman, D. K.

2010-12-01

352

Understanding Nuclear Receptor Form and Function Using Structural Biology  

PubMed Central

Nuclear receptors (NR) are a major transcription factor family whose members selectively bind small molecule lipophilic ligands and transduce those signals into specific changes in gene programs. For over two decades, structural biology efforts were directed exclusively on the individual ligand binding domains (LBDs) or DNA binding domains (DBDs) of NRs. These analyses revealed the basis for both ligand and DNA binding, and also revealed receptor conformations representing both the activated and repressed states. Additionally, crystallographic studies explained how NR LBD surfaces recognize discrete portions of transcriptional coregulators. The many structural snapshots of LBDs have also guided the development of synthetic ligands with therapeutic potential. Yet, the exclusive structural focus on isolated NR domains has made it difficult to conceptualize how all the NR polypeptide segments are coordinated physically and functionally in the context of receptor quaternary architectures. Newly emerged crystal structures of the PPAR?-RXR? heterodimer and HNF-4? homodimer have recently revealed the higher order organizations of these receptor complexes on DNA, as well as the complexity and uniqueness of their domain-domain interfaces. These emerging structural advances promise to better explain how signals in one domain can be allosterically transmitted to distal receptor domains, also providing much better frameworks for guiding future drug discovery efforts. PMID:24103914

Rastinejad, Fraydoon; Huang, Pengxiang; Chandra, Vikas; Khorasanizadeh, Sepideh

2013-01-01

353

The Role of the Met66 Brain-Derived Neurotrophic Factor Allele in the Recovery of Executive Functioning after Combat-Related Traumatic Brain Injury  

PubMed Central

Brain-derived neurotrophic factor (BDNF), a member of the neurotrophin family, promotes survival and synaptic plasticity in the human brain. The Val66Met polymorphism of the BDNF gene interferes with intracellular trafficking, packaging, and regulated secretion of this neurotrophin. The human prefrontal cortex (PFC) shows lifelong neuroplastic adaption implicating the Val66Met BDNF polymorphism in the recovery of higher-order executive functions after traumatic brain injury (TBI). In this study, we examined the effect of this BDNF polymorphism on the recovery of executive functioning after TBI. We genotyped a sample of male Vietnam combat veterans consisting of a frontal lobe lesion group with focal penetrating head injuries and a non-head-injured control group for the Val66Met BDNF polymorphism. The Delis–Kaplan Executive Function System as a standardized psychometric battery was administrated to examine key domains of executive functions. The results revealed that the Met allele but not the hypothesized Val allele promotes recovery of executive functioning. Overall, the Met66 carriers in the lesion group performed as well as the Met66 carriers in the control group. The Met66 allele accounted for 6.2% of variance for executive functioning independently of other significant predictors including preinjury intelligence, left hemisphere volume loss, and dorsolateral PFC volume loss. The findings point to different mechanisms of the Val66Met BDNF gene in complex phenotypes under normal and pathological conditions. A better understanding of these mechanisms could be instrumental in the development and application of effective therapeutic strategies to facilitate recovery from TBI. PMID:21228168

Krueger, Frank; Pardini, Matteo; Huey, Edward D.; Raymont, Vanessa; Solomon, Jeffrey; Lipsky, Robert H.; Hodgkinson, Colin A.; Goldman, David; Grafman, Jordan

2011-01-01

354

Altered baseline brain activity in children with ADHD revealed by resting-state functional MRI  

Microsoft Academic Search

In children with attention deficit hyperactivity disorder (ADHD), functional neuroimaging studies have revealed abnormalities in various brain regions, including prefrontal-striatal circuit, cerebellum, and brainstem. In the current study, we used a new marker of functional magnetic resonance imaging (fMRI), amplitude of low-frequency (0.01–0.08Hz) fluctuation (ALFF) to investigate the baseline brain function of this disorder. Thirteen boys with ADHD (13.0±1.4 years)

Zang Yu-Feng; He Yong; Zhu Chao-Zhe; Cao Qing-Jiu; Sui Man-Qiu; Liang Meng; Tian Li-Xia; Jiang Tian-Zi; Wang Yu-Feng

2007-01-01

355

Modafinil treatment prevents REM sleep deprivation-induced brain function impairment by increasing MMP-9 expression  

Microsoft Academic Search

Previous work showed that sleep deprivation (SD) impairs hippocampal-dependent cognitive function and synaptic plasticity, and a novel wake-promoting agent modafinil prevents SD-induced memory impairment in rat. However, the mechanisms by which modafinil prevented REM-SD-induced impairment of brain function remain poorly understood. In the present study, rats were sleep-deprived by using the modified multiple platform method and brain function was detected.

Bin He; Hua Peng; Ying Zhao; Hui Zhou; Zhongxin Zhao

2011-01-01

356

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

357

Enhanced Understand of Biological Systems Using Structure-Behavior-Function Models  

Microsoft Academic Search

An important issue in teaching interdisciplinary biologically inspired design is the external representations we use to foster understanding of biological systems. In this study we explore if functional models of biological systems, and in particular Structure-Behavior- Function (SBF) models, enable humans to better understand complex biological systems. The study compares the use of SBF models in answering questions about biological

Michael Helms; Svaroop Vattam; Ashok K. Goel; Jeannette Yen

2011-01-01

358

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

359

Intrinsic functional connectivity pattern-based brain parcellation using normalized cut  

NASA Astrophysics Data System (ADS)

In imaging data based brain network analysis, a necessary precursor for constructing meaningful brain networks is to identify functionally homogeneous regions of interest (ROIs) for defining network nodes. For parcellating the brain based on resting state fMRI data, normalized cut is one widely used clustering algorithm which groups voxels according to the similarity of functional signals. Due to low signal to noise ratio (SNR) of resting state fMRI signals, spatial constraint is often applied to functional similarity measures to generate smooth parcellation. However, improper spatial constraint might alter the intrinsic functional connectivity pattern, thus yielding biased parcellation results. To achieve reliable and least biased parcellation of the brain, we propose an optimization method for the spatial constraint to functional similarity measures in normalized cut based brain parcellation. Particularly, we first identify the space of all possible spatial constraints that are able to generate smooth parcellation, then find the spatial constraint that leads to the brain parcellation least biased from the intrinsic function pattern based parcellation, measured by the minimal Ncut value calculated based on the functional similarity measure of original functional signals. The proposed method has been applied to the parcellation of medial superior frontal cortex for 20 subjects based on their resting state fMRI data. The experiment results indicate that our method can generate meaningful parcellation results, consistent with existing functional anatomy knowledge.

Cheng, Hewei; Song, Dandan; Wu, Hong; Fan, Yong

2012-02-01

360

Functional Connectivity Magnetic Resonance Imaging Reveals Cortical Functional Connectivity in the Developing Brain  

E-print Network

in the Developing Brain Weili Lin, Ph.D.^1 , Quan Zhu, M.S.^ 2 , Wei Gao, M.S.^ 3 , Yasheng Chen, D.Sc.^ 1 , Cheng was utilized to depict brain regions exhibiting temporal synchronization, also known as resting brain pixel-by-pixel throughout the entire brain, identifying regions with high temporal correlation. Results

Utah, University of

361

Interspecies activity correlations reveal functional correspondence between monkey and human brain areas  

Microsoft Academic Search

Evolution-driven functional changes in the primate brain are typically assessed by aligning monkey and human activation maps using cortical surface expansion models. These models use putative homologous areas as registration landmarks, assuming they are functionally correspondent. For cases in which functional changes have occurred in an area, this assumption prohibits to reveal whether other areas may have assumed lost functions.

Dante Mantini; Uri Hasson; Viviana Betti; Mauro G Perrucci; Gian Luca Romani; Maurizio Corbetta; Guy A Orban; Wim Vanduffel

2012-01-01

362

Investigation of the large-scale functional brain networks modulated by acupuncture  

E-print Network

Investigation of the large-scale functional brain networks modulated by acupuncture Yuanyuan Fenga effects of acupuncture. Considering that acupuncture can induce long-lasting effects, several researchers have begun to pay attention to the sustained effects of acupuncture on the resting brain. Most

Tian, Jie

363

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

364

Using Structural Equation Modeling to Assess Functional Connectivity in the Brain: Power and Sample Size Considerations  

ERIC Educational Resources Information Center

The present study assessed the impact of sample size on the power and fit of structural equation modeling applied to functional brain connectivity hypotheses. The data consisted of time-constrained minimum norm estimates of regional brain activity during performance of a reading task obtained with magnetoencephalography. Power analysis was first…

Sideridis, Georgios; Simos, Panagiotis; Papanicolaou, Andrew; Fletcher, Jack

2014-01-01

365

Functional mapping of the human brain with near-infrared spectroscopy in the frequency-domain  

E-print Network

-to-noise ratio with respect to DC data. In this work, we have collected DC and phase data on the head of a humanFunctional mapping of the human brain with near-infrared spectroscopy in the frequency change) associated with brain activity and its evolution with time. MATERIALS AND METHODS The experiments

Fantini, Sergio

366

Drug exposure early in life: functional repercussions of changing neuropharmacology during sensitive periods of brain development  

Microsoft Academic Search

Exposure to drugs early in life can have long-lasting implications for brain structure and function. Effects on the developing nervous system, before homeostatic regulatory mechanisms are properly calibrated, differ from those on mature systems. Recent studies show that permanent alterations in brain pharmacology and cell signaling are induced by early drug exposure, producing hypo- or hyperresponsiveness to environmental or pharmacological

Gregg D Stanwood; Pat Levitt

2004-01-01

367

Omega3 fatty acids, energy substrates, and brain function during aging  

Microsoft Academic Search

The maintenance of optimal cognitive function is a central feature of healthy aging. Impairment in brain glucose uptake is common in aging associated cognitive deterioration, but little is known of how this problem arises or whether it can be corrected or bypassed. Several aspects of the challenge to providing the brain with an adequate supply of fuel during aging seem

Erika Freemantle; Milène Vandal; Jennifer Tremblay-Mercier; Sébastien Tremblay; Jean-Christophe Blachère; Michel E. Bégin; J. Thomas Brenna; Anthony Windust; Stephen C. Cunnane

2006-01-01

368

Sex differences in the brain: The relation between structure and function Geert J. de Vries a,  

E-print Network

Sex differences in the brain: The relation between structure and function Geert J. de Vries a 2009 Revised 10 March 2009 Accepted 12 March 2009 Keywords: Sex differences Sex similarities hypothesis was proposed, many sex differences have been found in behavior as well as structure of the brain

de Vries, Geert J.

369

Imaging correlates of brain function in monkeys and rats isolates a hippocampal subregion differentially  

E-print Network

Imaging correlates of brain function in monkeys and rats isolates a hippocampal subregion¶ , and Carol A. Barnes *Taub Institute for Research on Alzheimer's Disease and the Aging Brain, Center for Neurobiology and Behavior, and §Department of Neurology, Columbia University College of Physicians and Surgeons

Dukas, Reuven

370

Functional, perfusion and diffusion MRI of acute focal ischemic brain injury  

E-print Network

-risk,' and `ischemic' tissues associated with stroke during the acute phase. Brain tissues with perfusion deficits with the abnormal PWI area. The difference in the abnormal region defined by the PWI and DWI in acute strokeFunctional, perfusion and diffusion MRI of acute focal ischemic brain injury Qiang Shen1 , Hongxia

Duong, Timothy Q.

371

On the relationship between human brain functions and the foundations of physics, science, and technology  

Microsoft Academic Search

The objective of this paper is to discuss the relationship between the functional properties and information-processing modes of the human brain and the evolution of scientific thought. Science has emerged as a tool to carry out predictive operations that exceed the accuracy, temporal scale, and intrinsic operational limitations of the human brain. Yet the scientific method unavoidably reflects some fundamental

Juan G. Roederer

1978-01-01

372

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

373

Structural and functional brain development and its relation to cognitive development  

Microsoft Academic Search

Despite significant gains in the fields of pediatric neuroimaging and developmental neurobiology, surprisingly little is known about the developing human brain or the neural bases of cognitive development. This paper addresses MRI studies of structural and functional changes in the developing human brain and their relation to changes in cognitive processes over the first few decades of human life. Based

B. J. Casey; Jay N. Giedd; Kathleen M. Thomas

2000-01-01

374

Individual Differences in General Intelligence Correlate with Brain Function during Nonreasoning Tasks.  

ERIC Educational Resources Information Center

Administered Raven's Advanced Progressive Matrices to 22 adults and measured cerebral glucose activity as subjects viewed videos on 2 occasions. Data provide evidence that individual differences in intelligence correlate with brain function even when the brain is engaged in non-reasoning tasks. (SLD)

Haier, Richard J.; White, Nathan S.; Alkire, Michael T.

2003-01-01

375

Behind the scenes of functional brain imaging: A historical and physiological perspective  

Microsoft Academic Search

At the forefront of cognitive neuroscience re- search in normal humans are the new techniques of functional brain imaging: positron emission tomography and magnetic resonance imaging. The signal used by positron emission tomog- raphy is based on the fact that changes in the cellular activity of the brain of normal, awake humans and laboratory animals are accompanied almost invariably by

MARCUS E. RAICHLE

1998-01-01

376

Dorsal and Ventral Streams: A Framework for Understanding Aspects of the Functional Anatomy of Language  

ERIC Educational Resources Information Center

Despite intensive work on language-brain relations, and a fairly impressive accumulation of knowledge over the last several decades, there has been little progress in developing large-scale models of the functional anatomy of language that integrate neuropsychological, neuroimaging, and psycholinguistic data. Drawing on relatively recent…

Hickok, Gregory; Poeppel, David

2004-01-01

377

TBI-ROC Part One: Understanding Traumatic Brain Injury--An Introduction  

ERIC Educational Resources Information Center

This article is the first of a multi-part series on traumatic brain injury (TBI). Historically, TBI has received very limited national public policy attention and support. However since it has become the signature injury of the military conflicts in Iraq and Afghanistan, TBI has gained the attention of elected officials, military leaders,…

Trudel, Tina M.; Scherer, Marcia J.; Elias, Eileen

2011-01-01

378

Understanding the Brain as an Endogenously Active Mechanism William Bechtel (bill@mechanism.ucsd.edu)  

E-print Network

's laboratory at Liverpool from 1910 to 1913. He found that the isolated spinal cord, even when not receiving and spinal cord for walking, swimming, respiration, circulation, and other behaviors for which oscillatoryMRI, brain default network Introduction Observe a living organism, from a bacterium to a fellow human being

Bechtel, William

379

A new perspective on the functioning of the brain and the mechanisms behind conscious processes  

PubMed Central

An essential prerequisite for the development of a theory of consciousness is the clarification of the fundamental mechanisms underlying conscious processes. In this article I present an approach that sheds new light on these mechanisms. This approach builds on stochastic electrodynamics (SED), a promising theoretical framework that provides a deeper understanding of quantum systems and reveals the origin of quantum phenomena. I outline the most important concepts and findings of SED and interpret the neurophysiological body of evidence in the context of these findings, indicating that the functioning of the brain rests upon exactly the same principles that are characteristic for quantum systems. On this basis, I construct a new hypothesis on the mechanisms behind conscious processes and discuss the new perspectives this hypothesis opens up for consciousness research. In particular, it offers the possibility of elucidating the relationship between brain and consciousness, of specifying the connection between consciousness and information, and of answering the question of what distinguishes conscious processes from unconscious processes. PMID:23641229

Keppler, Joachim

2013-01-01

380

Early rehabilitation of higher cortical brain functioning in neurosurgery, humanizing the restoration of human skills after acute brain lesions  

Microsoft Academic Search

\\u000a \\u000a Objective  Increasingly more patients after brain damage survive, however, suffering from severe impairments of higher cerebral functioning.\\u000a \\u000a \\u000a \\u000a Methods  Patients after acute brain damage, mainly secondary to TBI, are referred for early neurosurgical rehabilitation. Our concept\\u000a follows the German Guidelines. It is based on a multidisciplinary team approach. Next-of kin are included in the treatment\\u000a and caring.\\u000a \\u000a \\u000a \\u000a Results  The essential aspect of early neurosurgical

K. R. H. von Wild

381

Functional Modularity of Background Activities in Normal and Epileptic Brain Networks  

NASA Astrophysics Data System (ADS)

We analyze the connectivity structure of weighted brain networks extracted from spontaneous magnetoencephalographic signals of healthy subjects and epileptic patients (suffering from absence seizures) recorded at rest. We find that, for the activities in the 5-14 Hz range, healthy brains exhibit a sparse connectivity, whereas the brain networks of patients display a rich connectivity with a clear modular structure. Our results suggest that modularity plays a key role in the functional organization of brain areas during normal and pathological neural activities at rest.

Chavez, M.; Valencia, M.; Navarro, V.; Latora, V.; Martinerie, J.

2010-03-01

382

Extrasynaptic Neurotransmission in the Modulation of Brain Function. Focus on the Striatal Neuronal–Glial Networks  

PubMed Central

Extrasynaptic neurotransmission is an important short distance form of volume transmission (VT) and describes the extracellular diffusion of transmitters and modulators after synaptic spillover or extrasynaptic release in the local circuit regions binding to and activating mainly extrasynaptic neuronal and glial receptors in the neuroglial networks of the brain. Receptor-receptor interactions in G protein-coupled receptor (GPCR) heteromers play a major role, on dendritic spines and nerve terminals including glutamate synapses, in the integrative processes of the extrasynaptic signaling. Heteromeric complexes between GPCR and ion-channel receptors play a special role in the integration of the synaptic and extrasynaptic signals. Changes in extracellular concentrations of the classical synaptic neurotransmitters glutamate and GABA found with microdialysis is likely an expression of the activity of the neuron-astrocyte unit of the brain and can be used as an index of VT-mediated actions of these two neurotransmitters in the brain. Thus, the activity of neurons may be functionally linked to the activity of astrocytes, which may release glutamate and GABA to the extracellular space where extrasynaptic glutamate and GABA receptors do exist. Wiring transmission (WT) and VT are fundamental properties of all neurons of the CNS but the balance between WT and VT varies from one nerve cell population to the other. The focus is on the striatal cellular networks, and the WT and VT and their integration via receptor heteromers are described in the GABA projection neurons, the glutamate, dopamine, 5-hydroxytryptamine (5-HT) and histamine striatal afferents, the cholinergic interneurons, and different types of GABA interneurons. In addition, the role in these networks of VT signaling of the energy-dependent modulator adenosine and of endocannabinoids mainly formed in the striatal projection neurons will be underlined to understand the communication in the striatal cellular networks. PMID:22675301

Fuxe, Kjell; Borroto-Escuela, Dasiel O.; Romero-Fernandez, Wilber; Diaz-Cabiale, Zaida; Rivera, Alicia; Ferraro, Luca; Tanganelli, Sergio; Tarakanov, Alexander O.; Garriga, Pere; Narváez, José Angel; Ciruela, Francisco; Guescini, Michele; Agnati, Luigi F.

2012-01-01

383

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

384

Selective Development of Anticorrelated Networks in the Intrinsic Functional Organization of the Human Brain  

E-print Network

We examined the normal development of intrinsic functional connectivity of the default network (brain regions typically deactivated for attention-demanding tasks) as measured by resting-state fMRI in children, adolescents, ...

Ofen, Noa

385

The Conundrum of Functional Brain Networks: Small-World Efficiency or Fractal Modularity  

PubMed Central

The human brain has been studied at multiple scales, from neurons, circuits, areas with well-defined anatomical and functional boundaries, to large-scale functional networks which mediate coherent cognition. In a recent work, we addressed the problem of the hierarchical organization in the brain through network analysis. Our analysis identified functional brain modules of fractal structure that were inter-connected in a small-world topology. Here, we provide more details on the use of network science tools to elaborate on this behavior. We indicate the importance of using percolation theory to highlight the modular character of the functional brain network. These modules present a fractal, self-similar topology, identified through fractal network methods. When we lower the threshold of correlations to include weaker ties, the network as a whole assumes a small-world character. These weak ties are organized precisely as predicted by theory maximizing information transfer with minimal wiring costs. PMID:22586406

Gallos, Lazaros K.; Sigman, Mariano; Makse, Hernán A.

2012-01-01

386

Advances in MRI to probe the functional and structural network of the macaque brain  

E-print Network

Diffusion MRI and fMRI have provided neuroscientists with non-invasive tools to probe the functional and structural network of the brain. Diffusion MRI is a neuroimaging technique capable of measuring the diffusion of water ...

Khachaturian, Mark Haig, 1979-

2007-01-01

387

Understanding in an instant: Neurophysiological evidence for mechanistic language circuits in the brain  

PubMed Central

How long does it take the human mind to grasp the idea when hearing or reading a sentence? Neurophysiological methods looking directly at the time course of brain activity indexes of comprehension are critical for finding the answer to this question. As the dominant cognitive approaches, models of serial/cascaded and parallel processing, make conflicting predictions on the time course of psycholinguistic information access, they can be tested using neurophysiological brain activation recorded in MEG and EEG experiments. Seriality and cascading of lexical, semantic and syntactic processes receives support from late (latency ?1/2 s) sequential neurophysiological responses, especially N400 and P600. However, parallelism is substantiated by early near-simultaneous brain indexes of a range of psycholinguistic processes, up to the level of semantic access and context integration, emerging already 100–250 ms after critical stimulus information is present. Crucially, however, there are reliable latency differences of 20–50 ms between early cortical area activations reflecting lexical, semantic and syntactic processes, which are left unexplained by current serial and parallel brain models of language. We here offer a mechanistic model grounded in cortical nerve cell circuits that builds upon neuroanatomical and neurophysiological knowledge and explains both near-simultaneous activations and fine-grained delays. A key concept is that of discrete distributed cortical circuits with specific inter-area topographies. The full activation, or ignition, of specifically distributed binding circuits explains the near-simultaneity of early neurophysiological indexes of lexical, syntactic and semantic processing. Activity spreading within circuits determined by between-area conduction delays accounts for comprehension-related regional activation differences in the millisecond range. PMID:19664815

Pulvermuller, Friedemann; Shtyrov, Yury; Hauk, Olaf

2009-01-01

388

Functional Connectivity in the Resting Brain: An Analysis Based on ICA  

Microsoft Academic Search

\\u000a The functional connectivity of the resting state, or default mode, of the human brain has been a research focus, because it\\u000a is reportedly altered in many neurological and psychiatric disorders. Among the methods to assess the functional connectivity\\u000a of the resting brain, independent component analysis (ICA) has been very useful. But how to choose the optimal number of separated\\u000a components

Xia Wu; Li Yao; Zhi-ying Long; Jie Lu; Kun-cheng Li

2006-01-01

389

Cognitive function and retinal and ischemic brain changes  

PubMed Central

Objective: To examine the association between retinopathy and cognitive decline or brain lesions and volumes in older women. Methods: This study included 511 women aged 65 and older who were simultaneously enrolled in the Women's Health Initiative Memory Study and the Sight Examination Study. In this analysis, we examined the link between retinopathy, assessed using fundus photography (2000–2002), cognitive performance over time assessed by the modified Mini-Mental State Examination (3MSE) (1996–2007), and white matter hyperintensities and lacunar infarcts in the basal ganglia. Results: Presence of retinopathy was associated with poorer 3MSE scores (mean difference = 1.01, SE: 0.43) (p = 0.019) over a 10-year follow-up period and greater ischemic volumes in the total brain (47% larger, p = 0.04) and the parietal lobe (68% larger, p = 0.01) but not with measures of regional brain atrophy. Conclusions: The correspondence we found between retinopathy and cognitive impairment, along with larger ischemic lesion volumes, strengthens existing evidence that retinopathy as a marker of small vessel disease is a risk factor for cerebrovascular disease that may influence cognitive performance and related brain changes. Retinopathy may be useful as a clinical tool if it can be shown to be an early marker related to neurologic outcomes. PMID:22422889

Espeland, M.A.; Klein, B.E.; Casanova, R.; Gaussoin, S.A.; Jackson, R.D.; Millen, A.E.; Resnick, S.M.; Rossouw, J.E.; Shumaker, S.A.; Wallace, R.; Yaffe, K.

2012-01-01

390

The Muscle Sensor for on-site neuroscience lectures to pave the way for a better understanding of brain-machine-interface research.  

PubMed

Neuroscience is an expanding field of science to investigate enigmas of brain and human body function. However, the majority of the public have never had the chance to learn the basics of neuroscience and new knowledge from advanced neuroscience research through hands-on experience. Here, we report that we produced the Muscle Sensor, a simplified electromyography, to promote educational understanding in neuroscience. The Muscle Sensor can detect myoelectric potentials which are filtered and processed as 3-V pulse signals to shine a light bulb and emit beep sounds. With this educational tool, we delivered "On-Site Neuroscience Lectures" in Japanese junior-high schools to facilitate hands-on experience of neuroscientific electrophysiology and to connect their text-book knowledge to advanced neuroscience researches. On-site neuroscience lectures with the Muscle Sensor pave the way for a better understanding of the basics of neuroscience and the latest topics such as how brain-machine-interface technology could help patients with disabilities such as spinal cord injuries. PMID:24140267

Koizumi, Amane; Nagata, Osamu; Togawa, Morio; Sazi, Toshiyuki

2014-01-01

391

Autism and genius: is there a link? The involvement of central brain loops and hypotheses for functional testing.  

PubMed

Mental processing is the product of the huge number of synaptic interactions that occur in the brain. It is easier to understand how brain functions can deteriorate than how they might be boosted. Lying at the border between the humanities, cognitive science and neurophysiology, some mental diseases offer new angles on this problematic issue. Despite their social deficits, autistic subjects can display unexpected and extraordinary skills in numerous fields, including music, the arts, calculation and memory. The advanced skills found in a subgroup of people with autism may be explained by their special mental functioning, in particular by their weak central coherence, one of the pivotal characteristics of the disorder. As a result of the increasing interest in autistic talent, there has recently emerged a tendency to screen any eccentric artist or scientist for traits of the autistic spectrum. Following this trend, we analyze the eccentricity of the popular pianist Glenn Gould and briefly discuss the major functional hypotheses on autistic hyperfunctioning, advancing proposals for functional testing. In particular, the potential involvement of rhythm-entrained systems and cerebro-cerebellar loops opens up new perspectives for the investigation of autistic disorders and brain hyperfunctioning. PMID:20630121

Boso, M; Emanuele, E; Prestori, Francesca; Politi, P; Barale, F; D'Angelo, E

2010-01-01

392

Functional connectivity in the mouse brain imaged by B-mode photoacoustic microscopy  

NASA Astrophysics Data System (ADS)

The increasing use of mouse models for human brain disease studies, coupled with the fact that existing functional imaging modalities cannot be easily applied to mice, presents an emerging need for a new functional imaging modality. Utilizing acoustic-resolution photoacoustic microscopy (AR-PAM), we imaged spontaneous cerebral hemodynamic fluctuations and their associated functional connections in the mouse brain. The images were acquired noninvasively in B-scan mode with a fast frame rate, a large field of view, and a high spatial resolution. At a location relative to the bregma 0, correlations were investigated inter-hemispherically between bilaterally homologous regions, as well as intra-hemispherically within the same functional regions. The functional connectivity in different functional regions was studied. The locations of these regions agreed well with the Paxinos mouse brain atlas. The functional connectivity map obtained in this study can then be used in the investigation of brain disorders such as stroke, Alzheimer's, schizophrenia, multiple sclerosis, autism, and epilepsy. Our experiments show that photoacoustic microscopy is capable to detect connectivities between different functional regions in B-scan mode, promising a powerful functional imaging modality for future brain research.

Nasiriavanaki, Mohammadreza; Xing, Wenxin; Xia, Jun; Wang, Lihong V.

2014-03-01

393

Somatostatinergic systems: an update on brain functions in normal and pathological aging  

PubMed Central

Somatostatin is highly expressed in mammalian brain and is involved in many brain functions such as motor activity, sleep, sensory, and cognitive processes. Five somatostatin receptors have been described: sst1, sst2 (A and B), sst3, sst4, and sst5, all belonging to the G-protein-coupled receptor family. During the recent years, numerous studies contributed to clarify the role of somatostatin systems, especially long-range somatostatinergic interneurons, in several functions they have been previously involved in. New advances have also been made on the alterations of somatostatinergic systems in several brain diseases and on the potential therapeutic target they represent in these pathologies. PMID:23230430

Martel, Guillaume; Dutar, Patrick; Epelbaum, Jacques; Viollet, Cecile

2012-01-01

394

Convergent functional genomics of schizophrenia: from comprehensive understanding to genetic risk prediction  

PubMed Central

We have used a translational convergent functional genomics (CFG) approach to identify and prioritize genes involved in schizophrenia, by gene-level integration of genome-wide association study data with other genetic and gene expression studies in humans and animal models. Using this polyevidence scoring and pathway analyses, we identify top genes (DISC1, TCF4, MBP, MOBP, NCAM1, NRCAM, NDUFV2, RAB18, as well as ADCYAP1, BDNF, CNR1, COMT, DRD2, DTNBP1, GAD1, GRIA1, GRIN2B, HTR2A, NRG1, RELN, SNAP-25, TNIK), brain development, myelination, cell adhesion, glutamate receptor signaling, G-protein–coupled receptor signaling and cAMP-mediated signaling as key to pathophysiology and as targets for therapeutic intervention. Overall, the data are consistent with a model of disrupted connectivity in schizophrenia, resulting from the effects of neurodevelopmental environmental stress on a background of genetic vulnerability. In addition, we show how the top candidate genes identified by CFG can be used to generate a genetic risk prediction score (GRPS) to aid schizophrenia diagnostics, with predictive ability in independent cohorts. The GRPS also differentiates classic age of onset schizophrenia from early onset and late-onset disease. We also show, in three independent cohorts, two European American and one African American, increasing overlap, reproducibility and consistency of findings from single-nucleotide polymorphisms to genes, then genes prioritized by CFG, and ultimately at the level of biological pathways and mechanisms. Finally, we compared our top candidate genes for schizophrenia from this analysis with top candidate genes for bipolar disorder and anxiety disorders from previous CFG analyses conducted by us, as well as findings from the fields of autism and Alzheimer. Overall, our work maps the genomic and biological landscape for schizophrenia, providing leads towards a better understanding of illness, diagnostics and therapeutics. It also reveals the significant genetic overlap with other major psychiatric disorder domains, suggesting the need for improved nosology. PMID:22584867

Ayalew, M; Le-Niculescu, H; Levey, D F; Jain, N; Changala, B; Patel, S D; Winiger, E; Breier, A; Shekhar, A; Amdur, R; Koller, D; Nurnberger, J I; Corvin, A; Geyer, M; Tsuang, M T; Salomon, D; Schork, N J; Fanous, A H; O'Donovan, M C; Niculescu, A B

2012-01-01

395

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

396

Multimodal Magnetic Resonance Imaging for Brain Disorders: Advances and Perspectives  

E-print Network

of such structural and functional information obtained from brain imaging may be able to enhance our understandingMultimodal Magnetic Resonance Imaging for Brain Disorders: Advances and Perspectives Tianzi Jiang Modern brain imaging technologies play essen- tial roles in our understanding of brain information

Jiang,Tianzi

397

The Functional Classification of Brain Damage-Related Vision Loss  

ERIC Educational Resources Information Center

This article provides a terminological framework to show the relationships among different types of visual deficits. It distinguishes between visual functions, which describe how the eye and the lower visual system function, and functional vision, which describes how a person functions. When visual functions are disturbed, the term "visual…

Colenbrander, August

2009-01-01

398

Amygdalar interhemispheric functional connectivity differs between the non-depressed and depressed human brain  

Microsoft Academic Search

The amygdalae are important, if not critical, brain regions for many affective, attentional and memorial processes, and dysfunction of the amygdalae has been a consistent finding in the study of clinical depression. Theoretical models of the functional neuroanatomy of both normal and psychopathological affective processes which posit cortical hemispheric specialization of functions have been supported by both lesion and functional

William Irwin; Michael J. Anderle; Heather C. Abercrombie; Stacey M. Schaefer; Ned H. Kalin; Richard J. Davidsona

2004-01-01

399

Perfusion-based high-resolution functional imaging in the human brain at 7 Tesla  

Microsoft Academic Search

Perfusion-based MRI measures cerebral blood flow (CBF) at the capillary level and can be used for functional studies based on the tight spatial coupling between brain activity and blood flow. Obtaining functional CBF maps with high spatial resolution is a major challenge because the CBF signal is intrinsically low and the SNR is critical. In the present work, CBF-based functional

Josef Pfeuffer; Gregor Adriany; Amir Shmuel; Essa Yacoub; Pierre-Francois Van De Moortele; Xiaoping Hu; Kamil Ugurbil

2002-01-01

400

Local Application of Drugs to Study Nicotinic Acetylcholine Receptor Function in Mouse Brain Slices  

PubMed Central

Tobacco use leads to numerous health problems, including cancer, heart disease, emphysema, and stroke. Addiction to cigarette smoking is a prevalent neuropsychiatric disorder that stems from the biophysical and cellular actions of nicotine on nicotinic acetylcholine receptors (nAChRs) throughout the central nervous system. Understanding the various nAChR subtypes that exist in brain areas relevant to nicotine addiction is a major priority. Experiments that employ electrophysiology techniques such as whole-cell patch clamp or two-electrode voltage clamp recordings are useful for pharmacological characterization of nAChRs of interest. Cells expressing nAChRs, such as mammalian tissue culture cells or Xenopus laevis oocytes, are physically isolated and are therefore easily studied using the tools of modern pharmacology. Much progress has been made using these techniques, particularly when the target receptor was already known and ectopic expression was easily achieved. Often, however, it is necessary to study nAChRs in their native environment: in neurons within brain slices acutely harvested from laboratory mice or rats. For example, mice expressing "hypersensitive" nAChR subunits such as ?4 L9?A mice 1 and ?6 L9?S mice 2, allow for unambiguous identification of neurons based on their functional expression of a specific nAChR subunit. Although whole-cell patch clamp recordings from neurons in brain slices is routinely done by the skilled electrophysiologist, it is challenging to locally apply drugs such as acetylcholine or nicotine to the recorded cell within a brain slice. Dilution of drugs into the superfusate (bath application) is not rapidly reversible, and U-tube systems are not easily adapted to work with brain slices. In this paper, we describe a method for rapidly applying nAChR-activating drugs to neurons recorded in adult mouse brain slices. Standard whole-cell recordings are made from neurons in slices, and a second micropipette filled with a drug of interest is maneuvered into position near the recorded cell. An injection of pressurized air or inert nitrogen into the drug-filled pipette causes a small amount of drug solution to be ejected from the pipette onto the recorded cell. Using this method, nAChR-mediated currents are able to be resolved with millisecond accuracy. Drug application times can easily be varied, and the drug-filled pipette can be retracted and replaced with a new pipette, allowing for concentration-response curves to be created for a single neuron. Although described in the context of nAChR neurobiology, this technique should be useful for studying many types of ligand-gated ion channels or receptors in neurons from brain slices. PMID:23128482

Engle, Staci E.; Broderick, Hilary J.; Drenan, Ryan M.

2012-01-01

401

Local application of drugs to study nicotinic acetylcholine receptor function in mouse brain slices.  

PubMed

Tobacco use leads to numerous health problems, including cancer, heart disease, emphysema, and stroke. Addiction to cigarette smoking is a prevalent neuropsychiatric disorder that stems from the biophysical and cellular actions of nicotine on nicotinic acetylcholine receptors (nAChRs) throughout the central nervous system. Understanding the various nAChR subtypes that exist in brain areas relevant to nicotine addiction is a major priority. Experiments that employ electrophysiology techniques such as whole-cell patch clamp or two-electrode voltage clamp recordings are useful for pharmacological characterization of nAChRs of interest. Cells expressing nAChRs, such as mammalian tissue culture cells or Xenopus laevis oocytes, are physically isolated and are therefore easily studied using the tools of modern pharmacology. Much progress has been made using these techniques, particularly when the target receptor was already known and ectopic expression was easily achieved. Often, however, it is necessary to study nAChRs in their native environment: in neurons within brain slices acutely harvested from laboratory mice or rats. For example, mice expressing "hypersensitive" nAChR subunits such as ?4 L9'A mice (1) and ?6 L9'S mice (2), allow for unambiguous identification of neurons based on their functional expression of a specific nAChR subunit. Although whole-cell patch clamp recordings from neurons in brain slices is routinely done by the skilled electrophysiologist, it is challenging to locally apply drugs such as acetylcholine or nicotine to the recorded cell within a brain slice. Dilution of drugs into the superfusate (bath application) is not rapidly reversible, and U-tube systems are not easily adapted to work with brain slices. In this paper, we describe a method for rapidly applying nAChR-activating drugs to neurons recorded in adult mouse brain slices. Standard whole-cell recordings are made from neurons in slices, and a second micropipette filled with a drug of interest is maneuvered into position near the recorded cell. An injection of pressurized air or inert nitrogen into the drug-filled pipette causes a small amount of drug solution to be ejected from the pipette onto the recorded cell. Using this method, nAChR-mediated currents are able to be resolved with millisecond accuracy. Drug application times can easily be varied, and the drug-filled pipette can be retracted and replaced with a new pipette, allowing for concentration-response curves to be created for a single neuron. Although described in the context of nAChR neurobiology, this technique should be useful for studying many types of ligand-gated ion channels or receptors in neurons from brain slices. PMID:23128482

Engle, Staci E; Broderick, Hilary J; Drenan, Ryan M

2012-01-01

402

Cannabis Use and Memory Brain Function in Adolescent Boys: A Cross-Sectional Multicenter Functional Magnetic Resonance Imaging Study  

ERIC Educational Resources Information Center

Objective: Early-onset cannabis use has been associated with later use/abuse, mental health problems (psychosis, depression), and abnormal development of cognition and brain function. During adolescence, ongoing neurodevelopmental maturation and experience shape the neural circuitry underlying complex cognitive functions such as memory and…

Jager, Gerry; Block, Robert I.; Luijten, Maartje; Ramsey, Nick F.

2010-01-01

403

People can understand descriptions of motion without activating visual motion brain regions  

E-print Network

What is the relationship between our perceptual and linguistic neural representations of the same event? We approached this question by asking whether visual perception of motion and understanding linguistic depictions of ...

Bedny, Marina

404

Neuropsychological function–brain structure relationships and stage of illness: An investigation into chronic and first-episode schizophrenia  

Microsoft Academic Search

Neuropsychological function–brain structure relationships may differ as a function of illness stage because of progressive brain matter loss through the course of schizophrenia. In this study, we tested whether neuropsychological function–brain structure relationships differed as a function of illness stage. In addition, we tested whether these relationships differed between older and young healthy controls. Function–structure relationships were examined in 35

Preethi Premkumar; Veena Kumari; Philip J. J. Corr; Dominic Fannon; Tonmoy Sharma

2008-01-01

405

Brain structural and functional alterations in patients with unilateral hearing loss.  

PubMed

Alterations of brain structure and functional connectivity have been described in patients with hearing impairments due to distinct pathogenesis; however, the influence of unilateral hearing loss (UHL) on brain morphology and regional brain activity is still not completely understood. In this study, we aim to investigate regional brain structural and functional alterations in patients with UHL. T1-weighted volumetric images and task-free fMRIs were acquired from 14 patients with right-sided UHL (pure tone average ? 40 dB HL) and 19 healthy controls. Hearing ability was assessed by pure tone audiometry. Voxel-based morphometry (VBM) was performed to detect brain regions with changed gray matter volume or white matter volume in UHL. The amplitude of low-frequency fluctuation (ALFF) was calculated to analyze brain activity at the baseline and was compared between two groups. Compared with controls, UHL patients showed decreased gray matter volume in bilateral posterior cingulate gyrus and precuneus, left superior/middle/inferior temporal gyrus, and right parahippocampal gyrus and lingual gyrus. Meanwhile, patients showed significantly decreased ALFF in bilateral precuneus, left inferior parietal lobule, and right inferior frontal gyrus and insula and increased ALFF in right inferior and middle temporal gyrus. These findings suggest that chronic UHL could induce brain morphological changes and is associated with aberrant baseline brain activity. PMID:25093284

Yang, Ming; Chen, Hua-Jun; Liu, Bin; Huang, Zhi-Chun; Feng, Yuan; Li, Jing; Chen, Jing-Ya; Zhang, Ling-Ling; Ji, Hui; Feng, Xu; Zhu, Xin; Teng, Gao-Jun

2014-10-01

406

Maternal and offspring pools of osteocalcin influence brain development and functions  

PubMed Central

The powerful regulation of bone mass exerted by the brain suggests the existence of bone-derived signals modulating this regulation or other functions of the brain. We show here that the osteoblast-derived hormone osteocalcin crosses the blood-brain barrier, binds to neurons of the brainstem, midbrain and hippocampus, enhances the synthesis of monoamine neurotransmitters, inhibits GABA synthesis, prevents anxiety and depression and favors learning and memory independently of its metabolic functions. In addition to these post-natal functions, maternal osteocalcin crosses the placenta during pregnancy and prevents neuronal apoptosis before embryos synthesize this hormone. As a result the severity of the neuro-anatomical defects and learning and memory deficits of Osteocalcin?/? mice is determined by the maternal genotype, and delivering osteocalcin to pregnant Osteocalcin?/? mothers rescues these abnormalities in their Osteocalcin?/? progeny. This study reveals that the skeleton via osteocalcin influences cognition and contributes to the maternal influence on fetal brain development. PMID:24074871

Oury, Franck; Khrimian, Lori; Denny, Christine. A.; Gardin, Antoine; Chamouni, Alexandre; Goeden, Nick; Huang, Yung-yu; Lee, Hojoon; Srinivas, Prashanth; Gao, Xiao-Bing; Suyama, Shigetomo; Langer, Thomas; Mann, John. J.; Horvath, Tamas. L.; Bonnin, Alexandre; Karsenty, Gerard

2013-01-01

407

Neuroelectrical decomposition of spontaneous brain activity measured with functional magnetic resonance imaging.  

PubMed

Spontaneous activity in the human brain occurs in complex spatiotemporal patterns that may reflect functionally specialized neural networks. Here, we propose a subspace analysis method to elucidate large-scale networks by the joint analysis of electroencephalography (EEG) and functional magnetic resonance imaging (fMRI) data. The new approach is based on the notion that the neuroelectrical activity underlying the fMRI signal may have EEG spectral features that report on regional neuronal dynamics and interregional interactions. Applying this approach to resting healthy adults, we indeed found characteristic spectral signatures in the EEG correlates of spontaneous fMRI signals at individual brain regions as well as the temporal synchronization among widely distributed regions. These spectral signatures not only allowed us to parcel the brain into clusters that resembled the brain's established functional subdivision, but also offered important clues for disentangling the involvement of individual regions in fMRI network activity. PMID:23796947

Liu, Zhongming; de Zwart, Jacco A; Chang, Catie; Duan, Qi; van Gelderen, Peter; Duyn, Jeff H

2014-11-01

408

The social brain in adolescence  

Microsoft Academic Search

The term 'social brain' refers to the network of brain regions that are involved in understanding others. Behaviour that is related to social cognition changes dramatically during human adolescence. This is paralleled by functional changes that occur in the social brain during this time, in particular in the medial prefrontal cortex and the superior temporal sulcus, which show altered activity

Sarah-Jayne Blakemore

2008-01-01

409

Metabolomics: An Essential Tool to Understand the Function of Peroxisome ProliferatorActivated Receptor Alpha  

E-print Network

Metabolomics: An Essential Tool to Understand the Function of Peroxisome Proliferator ABSTRACT The peroxisome proliferator�activated receptor (PPAR) family of nuclear hormone transcription. Keywords: metabolomics; liver; PPARa; chromatography; mass spectrometry. INTRODUCTION The peroxisome

Omiecinski, Curtis

410

Differential effects of the ApoE4 genotype on brain structure and function.  

PubMed

The apolipoprotein E ?4 allele is a well established genetic risk factor for sporadic Alzheimer's disease. It is associated with structural and functional brain changes in healthy young, middle-aged and elderly subjects. In the current study, we assessed the impact of the ApoE genotype on brain macro- and microstructure, cognitive functioning and brain activity in fifty healthy young subjects (25 ApoE ?4 (?4+) carriers and 25 non-carriers (?4-), mean age 26.4±4.6years). We used diffusion tensor imaging (DTI) and voxel based morphometry (VBM) to assess brain structure, an extensive neuropsychological battery to test cognitive functioning and event-related functional magnetic resonance imaging (fMRI) to capture brain activity during episodic memory encoding and retrieval. ApoE ?4 carriers differed from non-carriers in fMRI activations but not in cognitive performance nor in brain micro- and macrostructure. These results suggest functional alterations in the episodic memory network that are modulated by the ?4 allele and might precede clinical or structural neurodegeneration. PMID:24296331

Matura, Silke; Prvulovic, David; Jurcoane, Alina; Hartmann, Daniel; Miller, Julia; Scheibe, Monika; O'Dwyer, Laurence; Oertel-Knöchel, Viola; Knöchel, Christian; Reinke, Britta; Karakaya, Tarik; Fußer, Fabian; Pantel, Johannes

2014-04-01

411

Traumatic Brain Injury Inpatient Rehabilitation  

ERIC Educational Resources Information Center

Traumatic brain injuries (TBI) can cause multiple medical and functional problems. As the brain is involved in regulating nearly every bodily function, a TBI can affect any part of the body and aspect of cognitive, behavioral, and physical functioning. However, TBI affects each individual differently. Optimal management requires understanding the…

Im, Brian; Schrer, Marcia J.; Gaeta, Raphael; Elias, Eileen

2010-01-01

412

Understanding Early Elementary Children's Conceptual Knowledge of Plant Structure and Function through Drawings  

ERIC Educational Resources Information Center

This study examined children's drawings to explain children's conceptual understanding of plant structure and function. The study explored whether the children's drawings accurately reflect their conceptual understanding about plants in a manner that can be interpreted by others. Drawing, survey, interview, and observational data…

Anderson, Janice L.; Ellis, Jane P.; Jones, Alan M.

2014-01-01

413

Understanding the role of conscientiousness in healthy aging: where does the brain come in?  

PubMed

In reviewing this impressive series of articles, I was struck by 2 points in particular: (a) the fact that the empirically oriented articles focused on analyses of data from very large samples, with the articles by Friedman, Kern, Hampson, and Duckworth (2014) and Kern, Hampson, Goldbert, and Friedman (2014) highlighting an approach to merging existing data sets through use of "metric bridges" to address key questions not addressable through 1 data set alone, and (b) the fact that the articles as a whole included limited mention of neuroscientific (i.e., brain research) concepts, methods, and findings. One likely reason for the lack of reference to brain-oriented work is the persisting gap between smaller sample size lab-experimental and larger sample size multivariate-correlational approaches to psychological research. As a strategy for addressing this gap and bringing a distinct neuroscientific component to the National Institute on Aging's conscientiousness and health initiative, I suggest that the metric bridging approach highlighted by Friedman and colleagues could be used to connect existing large-scale data sets containing both neurophysiological variables and measures of individual difference constructs to other data sets containing richer arrays of nonphysiological variables-including data from longitudinal or twin studies focusing on personality and health-related outcomes (e.g., Terman Life Cycle study and Hawaii longitudinal studies, as described in the article by Kern et al., 2014). PMID:24773108

Patrick, Christopher J

2014-05-01

414

The retinal wholemount technique: a window to understanding the brain and behaviour.  

PubMed

The accessibility of the vertebrate retina has provided the opportunity to assess various parameters of the visual abilities of a range of species. This thin but complex extension of the brain achieves a large proportion of the necessary visual processing of an optical image before information is delivered to the brain as neural impulses. Studies of the retina as a wholemount or a flattened sheet of neural tissue are abundant due to the large amount of information that can be analysed, as follows: the level of summation or convergence; the coverage, stratification and potential sites of synaptic connections; the spatial resolving power; the arrangement of neuronal arrays or mosaics; electrophysiological access for the recording of responses to visual stimuli; the spatial arrangement of cell dendritic fields; location of retinal 'blind spots' (optic nerve, falciform process and pecten); topographic differences in retinal cell sampling; spectral filters, and reflective structures. The present study examines all aspects of the wholemount technique, including enucleation, fixation, retinal extraction, flattening, staining, visualization of labelled cells and stereological mapping of cell density. Uniquely, it highlights the crucial technical and often species-specific differences encountered when examining a range of vertebrate taxa (fishes, reptiles, birds and mammals). This broad comparative approach will enable future studies to overcome technical difficulties, thus permitting larger conceptual questions to be posed regarding the diversity of visual tasks across phylogenetic boundaries. PMID:22142853

Ullmann, Jeremy F P; Moore, Bret A; Temple, Shelby E; Fernández-Juricic, Esteban; Collin, Shaun P

2012-01-01

415

COMT Val158Met and cognitive and functional outcomes after traumatic brain injury.  

PubMed

There is significant variability in long-term outcomes after traumatic brain injury (TBI), making accurate prognosis difficult. In seeking to enhance understanding of outcomes, this study aimed to investigate whether COMT Val(158)Met allele status was associated with performance on neuropsychological measures of attention and working memory, executive functioning, learning and memory, and speed of information processing in the early rehabilitation phase. The study also aimed to examine whether the COMT polymorphism was associated with longer-term functional outcomes. A total of 223 participants (71.3% male) with moderate-to-severe TBI were recruited as rehabilitation inpatients to participate in a prospective, longitudinal head injury outcome study. The three COMT genotype groups (Val/Val, Val/Met, and Met/Met) were well matched for estimated full-scale IQ, years of education, age at injury, and injury severity. Results showed no significant difference between genotypes on neuropsychological measures (all p>0.05) or functional outcome, as measured by the Glasgow Outcome Scale-Extended (GOS-E), after controlling for age, education, and severity of injury. The presence of frontal lobe pathology was also not associated with cognitive performance. Those with greater injury severity (i.e., longer duration of post-traumatic amnesia) performed more poorly on measures of processing speed and verbal new learning and recall. It was concluded that there was little support for the influence of COMT Val(158)Met on cognitive function, or functional outcome measures, in the acute rehabilitation phase after TBI. PMID:24786534

Willmott, Catherine; Withiel, Toni; Ponsford, Jennie; Burke, Richard

2014-09-01

416

Dietary Polyphenols as Modulators of Brain Functions: Biological Actions and Molecular Mechanisms Underpinning Their Beneficial Effects  

PubMed Central

Accumulating evidence suggests that diet and lifestyle can play an important role in delaying the onset or halting the progression of age-related health disorders and to improve cognitive function. In particular, polyphenols have been reported to exert their neuroprotective actions through the potential to protect neurons against injury induced by neurotoxins, an ability to suppress neuroinflammation, and the potential to promote memory, learning, and cognitive function. Despite significant advances in our understanding of the biology of polyphenols, they are still mistakenly regarded as simply acting as antioxidants. However, recent evidence suggests that their beneficial effects involve decreases in oxidative/inflammatory stress signaling, increases in protective signaling and neurohormetic effects leading to the expression of genes that encode antioxidant enzymes, phase-2 enzy