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1

Understanding entangled cerebral networks: a prerequisite for restoring brain function with brain-computer interfaces  

PubMed Central

Historically, cerebral processing has been conceptualized as a framework based on statically localized functions. However, a growing amount of evidence supports a hodotopical (delocalized) and flexible organization. A number of studies have reported absence of a permanent neurological deficit after massive surgical resections of eloquent brain tissue. These results highlight the tremendous plastic potential of the brain. Understanding anatomo-functional correlates underlying this cerebral reorganization is a prerequisite to restore brain functions through brain-computer interfaces (BCIs) in patients with cerebral diseases, or even to potentiate brain functions in healthy individuals. Here, we review current knowledge of neural networks that could be utilized in the BCIs that enable movements and language. To this end, intraoperative electrical stimulation in awake patients provides valuable information on the cerebral functional maps, their connectomics and plasticity. Overall, these studies indicate that the complex cerebral circuitry that underpins interactions between action, cognition and behavior should be throughly investigated before progress in BCI approaches can be achieved.

Mandonnet, Emmanuel; Duffau, Hugues

2014-01-01

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.

3

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

4

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

5

Understanding Brain Tumors  

MedlinePLUS

... org > Brain Tumor Information > Understanding Brain Tumors Understanding Brain Tumors While it is normal to feel scared, ... to Know About Brain Tumors . What is a Brain Tumor? A brain tumor is an abnormal growth? ...

6

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

PubMed Central

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 profile of brain endothelial cells with those purified from the liver and lung, we have generated a comprehensive resource of transcripts that are enriched in the BBB forming endothelial cells of the brain. Through this comparison we have identified novel tight junction proteins, transporters, metabolic enzymes, signaling components, and unknown transcripts whose expression is enriched in central nervous system (CNS) endothelial cells. This analysis has identified that RXRalpha signaling cascade is specifically enriched at the BBB, implicating this pathway in regulating this vital barrier. This dataset provides a resource for understanding CNS endothelial cells and their interaction with neural and hematogenous cells.

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

2010-01-01

7

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

PubMed

Early life experiences have powerful effects on the brain and body lasting throughout the entire life span 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-quality 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

2008-10-01

8

Gait and Cognition: A Complementary Approach to Understanding Brain Function and the Risk of Falling  

PubMed Central

Until recently, clinicians and researchers have performed gait assessments and cognitive assessments separately when evaluating older adults. Increasing evidence from clinical practice, epidemiological studies, and clinical trials shows that gait and cognition are inter-related in older adults. Quantifiable alterations in gait among older adults are associated with falls, dementia, and disability. At the same time, emerging evidence indicates that early disturbances in cognitive processes such as attention, executive function, and working memory are associated with slower gait and gait instability during single and dual-task testing, and that these cognitive disturbances assist in the prediction of future mobility loss, falls, and progression to dementia. This paper reviews the importance of the gait-cognition inter-relationship in aging and presents evidence that gait assessments can provide a window into the understanding of cognitive function and dysfunctions, and fall risk in older people in clinical practice. To this end, the benefits of dual-task gait assessments (e.g., walking while performing an attention-demanding task) as a marker of fall risk are summarized. Further, we also present a potential complementary approach for reducing the risk of falls by improving certain aspects of cognition through both non-pharmacological and pharmacological treatments. Untangling the relationship between early gait disturbances and early cognitive changes may be helpful for identifying older adults at higher risk of experiencing mobility decline, falls and the progression to dementia.

Montero-Odasso, Manuel; Verghese, Joe; Beauchet, Olivier; Hausdorff, Jeffrey M.

2012-01-01

9

Understanding brain dysfunction in sepsis.  

PubMed

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

Sonneville, Romain; Verdonk, Franck; Rauturier, Camille; Klein, Isabelle F; Wolff, Michel; Annane, Djillali; Chretien, Fabrice; Sharshar, Tarek

2013-01-01

10

Avian brains and a new understanding of vertebrate brain evolution  

PubMed Central

We believe that names have a powerful influence on the experiments we do and the way in which we think. For this reason, and in the light of new evidence about the function and evolution of the vertebrate brain, an international consortium of neuroscientists has reconsidered the traditional, 100-year-old terminology that is used to describe the avian cerebrum. Our current understanding of the avian brain —in particular the neocortex-like cognitive functions of the avian pallium — requires a new terminology that better reflects these functions and the homologies between avian and mammalian brains.

2008-01-01

11

Development of the Brain’s Functional Network Architecture  

Microsoft Academic Search

A full understanding of the development of the brain’s functional network architecture requires not only an understanding\\u000a of developmental changes in neural processing in individual brain regions but also an understanding of changes in inter-regional\\u000a interactions. Resting state functional connectivity MRI (rs-fcMRI) is increasingly being used to study functional interactions\\u000a between brain regions in both adults and children. We briefly

Alecia C. Vogel; Jonathan D. Power; Steven E. Petersen; Bradley L. Schlaggar

2010-01-01

12

Understanding complexity in the human brain  

PubMed Central

Although the ultimate aim of neuroscientific enquiry is to gain an understanding of the brain and how its workings relate to the mind, the majority of current efforts are largely focused on small questions using increasingly detailed data. However, it might be possible to successfully address the larger question of mind–brain mechanisms if the cumulative findings from these neuroscientific studies are coupled with complementary approaches from physics and philosophy. The brain, we argue, can be understood as a complex system or network, in which mental states emerge from the interaction between multiple physical and functional levels. Achieving further conceptual progress will crucially depend on broad-scale discussions regarding the properties of cognition and the tools that are currently available or must be developed in order to study mind–brain mechanisms.

Bassett, Danielle S.; Gazzaniga, Michael S.

2011-01-01

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

Assessing brain stem function.  

PubMed

Intraoperative neurophysiologic monitoring provides objective measures of nervous system function that are of value when operating in proximity to the brain stem. Real-time measurements of function can be correlated to operative manipulations in order to reduce the risk of damage in critically important regions. Techniques for evaluating brain stem function clinically and electrophysiologically are presented along with their applications during surgery of the brain stem. PMID:8353442

Sclabassi, R J; Kalia, K K; Sekhar, L; Jannetta, P J

1993-07-01

15

Brain Structure-function Couplings (FY11).  

National Technical Information Service (NTIS)

In FY11, a collaborative team of researchers began a new Director's Strategic Initiative (DSI) to examine brain structure-function couplings. The effort aims to develop a multidisciplinary, multiscale understanding of the relationship between the brain's ...

A. Dagro J. Vettel R. Kraft S. Gordon S. Kerick

2012-01-01

16

Brain Dynamics Promotes Function  

NASA Astrophysics Data System (ADS)

Dynamical structure in the brain promotes biological function. Natural scientists look for correlations between measured electrical signals and behavior or mental states. Computational scientists have new opportunities to receive ’algorithmic’ inspiration from brain processes and propose computational paradigms. Thus a tradition which dates back to the 1940s with neural nets research is renewed. Real processes in the brain are ’complex’ and withstand trivial descriptions. However, dynamical complexity need not be at odds with a computational description of the phenomena and with the inspiration for algorithms that actually compute something in an engineering sense. We engage this complexity from a computational viewpoint, not excluding dynamical regimes that a number of authors are willing to label as chaos. The key question is: what may we be missing computation-wise if we overlook brain dynamics? At this point in brain research, we are happy if we can at least provide a partial answer.

Lourenço, Carlos

17

Functional Brain Imaging  

PubMed Central

Executive Summary Objective The objective of this analysis is to review a spectrum of functional brain imaging technologies to identify whether there are any imaging modalities that are more effective than others for various brain pathology conditions. This evidence-based analysis reviews magnetoencephalography (MEG), magnetic resonance spectroscopy (MRS), positron emission tomography (PET), and functional magnetic resonance imaging (fMRI) for the diagnosis or surgical management of the following conditions: Alzheimer’s disease (AD), brain tumours, epilepsy, multiple sclerosis (MS), and Parkinson’s disease (PD). Clinical Need: Target Population and Condition Alzheimer’s disease is a progressive, degenerative, neurologic condition characterized by cognitive impairment and memory loss. The Canadian Study on Health and Aging estimated that there will be 97,000 incident cases (about 60,000 women) of dementia (including AD) in Canada in 2006. In Ontario, there will be an estimated 950 new cases and 580 deaths due to brain cancer in 2006. Treatments for brain tumours include surgery and radiation therapy. However, one of the limitations of radiation therapy is that it damages tissue though necrosis and scarring. Computed tomography (CT) and magnetic resonance imaging (MRI) may not distinguish between radiation effects and resistant tissue, creating a potential role for functional brain imaging. Epilepsy is a chronic disorder that provokes repetitive seizures. In Ontario, the rate of epilepsy is estimated to be 5 cases per 1,000 people. Most people with epilepsy are effectively managed with drug therapy; but about 50% do not respond to drug therapy. Surgical resection of the seizure foci may be considered in these patients, and functional brain imaging may play a role in localizing the seizure foci. Multiple sclerosis is a progressive, inflammatory, demyelinating disease of the central nervous system (CNS). The cause of MS is unknown; however, it is thought to be due to a combination of etiologies, including genetic and environmental components. The prevalence of MS in Canada is 240 cases per 100,000 people. Parkinson’s disease is the most prevalent movement disorder; it affects an estimated 100,000 Canadians. Currently, the standard for measuring disease progression is through the use of scales, which are subjective measures of disease progression. Functional brain imaging may provide an objective measure of disease progression, differentiation between parkinsonian syndromes, and response to therapy. The Technology Being Reviewed Functional Brain Imaging Functional brain imaging technologies measure blood flow and metabolism. The results of these tests are often used in conjunction with structural imaging (e.g., MRI or CT). Positron emission tomography and MRS identify abnormalities in brain tissues. The former measures abnormalities through uptake of radiotracers in the brain, while the latter measures chemical shifts in metabolite ratios to identify abnormalities. The potential role of functional MRI (fMRI) is to identify the areas of the brain responsible for language, sensory and motor function (sensorimotor cortex), rather than identifying abnormalities in tissues. Magnetoencephalography measures magnetic fields of the electric currents in the brain, identifying aberrant activity. Magnetoencephalography may have the potential to localize seizure foci and to identify the sensorimotor cortex, visual cortex and auditory cortex. In terms of regulatory status, MEG and PET are licensed by Health Canada. Both MRS and fMRI use a MRI platform; thus, they do not have a separate licence from Health Canada. The radiotracers used in PET scanning are not licensed by Health Canada for general use but can be used through a Clinical Trials Application. Review Strategy The literature published up to September 2006 was searched in the following databases: MEDLINE, MEDLINE In-Process & Other Non-Indexed Citations, EMBASE, Cochrane Database of Systematic Reviews, CENTRAL, and International Network of Agencies for H

2006-01-01

18

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.

Pandya, Sunil K.

2011-01-01

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

Brain foods: the effects of nutrients on brain function  

PubMed Central

It has long been suspected that the relative abundance of specific nutrients can affect cognitive processes and emotions. Newly described influences of dietary factors on neuronal function and synaptic plasticity have revealed some of the vital mechanisms that are responsible for the action of diet on brain health and mental function. Several gut hormones that can enter the brain, or that are produced in the brain itself, influence cognitive ability. In addition, well-established regulators of synaptic plasticity, such as brain-derived neurotrophic factor, can function as metabolic modulators, responding to peripheral signals such as food intake. Understanding the molecular basis of the effects of food on cognition will help us to determine how best to manipulate diet in order to increase the resistance of neurons to insults and promote mental fitness.

Gomez-Pinilla, Fernando

2009-01-01

21

Fostering Literacy through Understanding Brain Mechanisms.  

ERIC Educational Resources Information Center

Some current ideas concerning the brain mechanisms of reading are presented. An impediment to educational applications of brain research is the remoteness of the classroom from brain research laboratories. An international plan is outlined to bring scientists and educators together to examine current knowledge about brain mechanisms involved in…

McCandliss, Bruce D.; Posner, Michael I.

2003-01-01

22

Synergetics of brain function.  

PubMed

Several brain functions such as movement coordination and visual perception are analysed in terms of synergetics, an interdisciplinary field of research dealing with spontaneous pattern formation. Accordingly, the brain is conceived as a self-organizing system operating close to instabilities where its activities are governed by collective variables, the order parameters, that enslave the individual parts, i.e., the neurons. In this approach, emphasis is laid on qualitative changes of behavioral and neuronal activities. These concepts are substantiated by detailed experimental and theoretical studies of the coordination of finger movements by direct observation of their changes and MEG measurements. In its main part, this paper deals with visual pattern recognition. Using general properties of order parameters, at the phenomenological level bistability, hysteresis and oscillations of visual perception can be modelled. Then, at the microscopic level, a network of pulse-coupled neurons is treated, where the dynamics of the dendritic currents as well as the axonic pulses (spikes) are taken into account. Both pulse-synchronization as well as pattern recognition are treated. In the high pulse frequency limit the attractor network of the synergetic computer is recovered. In the next step, the concept of quasi-attractors is mathematically formulated where due to saturation of attention attractors are closed. Depending on incoming signals, the visual system thus wanders from quasi-attractor to quasi-attractor. The paper includes an interpretation of consciousness in terms of order parameters as well as a discussion on linearity versus nonlinearity, the binding problem, and the psychological "present". PMID:16527368

Haken, Hermann

2006-05-01

23

Functional Lateralization of the Brain.  

ERIC Educational Resources Information Center

Research concerning lateralization of human brain functions is examined in light of the recent publication of the Kaufman Assessment Battery for Children. Following a review of research methodologies and functions ascribed to the hemispheres of the brain, differences are portrayed as complementary and coexisting modes of cognitive processing.…

Dean, Raymond S.

1984-01-01

24

Forthergillian Lecture. Imaging human brain function.  

PubMed

The non-invasive brain scanning techniques introduced a quarter of a century ago have become crucial for diagnosis in clinical neurology. They have also been used to investigate brain function and have provided information about normal activity and pathogenesis. They have been used to investigate functional specialization in the brain and how specialized areas communicate to generate complex integrated functions such as speech, memory, the emotions and so on. The phenomenon of brain plasticity is poorly understood and yet clinical neurologists are aware, from everyday observations, that spontaneous recovery from brain lesions is common. An improved understanding of the mechanisms of recovery may generate new therapeutic strategies and indicate ways of modulating mechanisms that promote plastic compensation for loss of function. The main methods used to investigate these issues are positron emission tomography and magnetic resonance imaging (M.R.I.). M.R.I. is also used to map brain structure. The techniques of functional brain mapping and computational morphometrics depend on high performance scanners and a validated set of analytic statistical procedures that generate reproducible data and meaningful inferences from brain scanning data. The motor system presents a good paradigm to illustrate advances made by scanning towards an understanding of plasticity at the level of brain areas. The normal motor system is organized in a nested hierarchy. Recovery from paralysis caused by internal capsule strokes involves functional reorganization manifesting itself as changed patterns of activity in the component brain areas of the normal motor system. The pattern of plastic modification depends in part on patterns of residual or disturbed connectivity after brain injury. Therapeutic manipulations in patients with Parkinson's disease using deep brain stimulation, dopaminergic agents or fetal mesencephalic transplantation provide a means to examine mechanisms underpinning plastic change. Other models of plastic change, such as normal visuospatial learning or re-establishing speech comprehension after cochlear implantation in the deaf illustrate how patterns of brain function adapt over time. Limitations of the scanning techniques and prospects for the future are discussed in relation to new developments in the neuroimaging field. PMID:14509213

Frackowiak, R S

25

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

26

Evolution of Cognitive Function via Redeployment of Brain Areas  

Microsoft Academic Search

Part of understanding the functional organization of the brain is understanding how it evolved. The current study suggests that although the brain may have originally emerged as an organ with functionally dedicated regions, the creative reuse of these regions has played a significant role in its evolutionary development. This would parallel the evolution of other capabilities wherein existing struc- tures,

MICHAEL L. ANDERSON

2007-01-01

27

Brain Research: The Necessity for Separating Sites, Actions and Functions.  

ERIC Educational Resources Information Center

Educators, as applied scientists, must work in partnership with investigative scientists who are researching brain functions in order to reach a better understanding of gifted students and students who are intelligent but do not learn. Improper understanding of brain functions can cause gross errors in educational placement. Until recently, the…

Meeker, Mary

28

Radiotracers for functional brain imaging  

SciTech Connect

The rapid growth of nuclear medicine 25 years ago was in large part related to the success of brain tumor imaging using radiopharmaceuticals designed to detect changes in the blood-brain barrier (BBB). The success of computed tomography, and more recently nuclear magnetic resonance, in imaging these lesions has all but eliminated the use of radioactive agents for brain tumor detection. But, in recent years there has been a new wave of interest in isotope studies of the brain. The recent emphasis has been on agents which enter the brain across the BBB and are designed to provide functional data ranging from regional perfusion and metabolism to the distribution of binding sites for neuroactive compounds. While none of these new radiopharmaceuticals has yet come into widespread clinical application, the research results already achieved clearly indicate that brain imaging will again be an important aspect of nuclear medicine practice. 51 references.

Blau, M.

1985-10-01

29

Imaging visual function of the human brain  

SciTech Connect

Imaging of human brain structure and activity with particular reference to visual function is reviewed along with methods of obtaining the data including computed tomographic (CT) scan, magnetic resonance imaging (MRI), magnetic resonance spectroscopy (MRS), and positron emission tomography (PET). The literature is reviewed and the potential for a new understanding of brain visual function is discussed. PET is reviewed from basic physical principles to the most recent visual brain findings with oxygen-15. It is shown that there is a potential for submillimeter localization of visual functions with sequentially different visual stimuli designed for the temporal separation of the responses. Single photon emission computed tomography (SPECT), a less expensive substitute for PET, is also discussed. MRS is covered from basic physical principles to the current state of the art of in vivo biochemical analysis. Future possible clinical applications are discussed. Improved understanding of the functional neural organization of vision and brain will open a window to maps and circuits of human brain function.119 references.

Marg, E.

1988-10-01

30

Minds, Brains, and Difference in Personal Understandings  

ERIC Educational Resources Information Center

If education is to make a difference it is widely acknowledged that we must aim to educate for understanding, but this means being clear about what we mean by understanding. This paper argues for a concept of personal understanding, recognising both the commonality and individuality of each pupil's understandings, and the relationship between…

Sankey, Derek

2007-01-01

31

Functional community analysis of brain: A new approach for EEG-based investigation of the brain pathology  

Microsoft Academic Search

Analysis of structure of the brain functional connectivity (SBFC) is a fundamental issue for understanding of the brain cognition as well as the pathology of brain disorders. Analysis of communities among sub-parts of a system is increasingly used for social, ecological, and other networks. This paper presents a new methodology for investigation of the SBFC and understanding of the brain

Mehran Ahmadlou; Hojjat Adeli

2011-01-01

32

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

33

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.

Honey, G; Fletcher, P; Bullmore, E

2002-01-01

34

Supporting Parents with Two Essential Understandings: Attachment and Brain Development.  

ERIC Educational Resources Information Center

Readiness to learn is a constant state. Two critical aspects of early childhood provide parents sufficient understanding of their child's development: attachment and brain development. Children develop attachments to caregivers but need consistent parental care and love. Human brains continue to quickly grow during the first two years of life.…

Berger, Eugenia Hepworth

1999-01-01

35

Selenium and selenoprotein function in brain disorders.  

PubMed

Selenoproteins are important for normal brain function, and decreased function of selenoproteins can lead to impaired cognitive function and neurological disorders. This review examines the possible roles of selenoproteins in Alzheimer's disease (AD), Parkinson's disease (PD), Huntington's disease (HD), and epilepsy. Selenium deficiency is associated with cognitive decline, and selenoproteins may be helpful in preventing neurodegeneration in AD. PD is associated with impaired function of glutathione peroxidase selenoenzymes. In HD, selenium deters lipid peroxidation by increasing specific glutathione peroxidases. Selenium deficiency increases risk of seizures in epilepsy, whereas supplementation may help to alleviate seizures. Further studies on the mechanisms of selenoprotein function will increase our understanding of how selenium and selenoproteins can be used in treatment and prevention of brain disorders. PMID:24668686

Pillai, Roshan; Uyehara-Lock, Jane H; Bellinger, Frederick P

2014-04-01

36

Using Adaptive Dynamic Programming to Understand and Replicate Brain Intelligence: the Next Level Design  

Microsoft Academic Search

Since the 1960s I proposed that we could understand and replicate the highest level of intelligence seen in the brain, by building ever more capable and general systems for adaptive dynamic programming (ADP), which is like reinforcement learning but based on approximating the Bellman equation and allowing the controller to know its utility function. Growing empirical evidence on the brain

Paul J. Werbos

2006-01-01

37

Understanding the functional neuroanatomy of acquired prosopagnosia  

Microsoft Academic Search

One of the most remarkable disorders following brain damage is prosopagnosia, the inability to recognize faces. While a number of cases of prosopagnosia have been described at the behavioral level, the functional neuroanatomy of this face recognition impairment, and thus the brain regions critically involved in normal face recognition, has never been specified in great detail. Here, we used anatomical

Bettina Sorger; Rainer Goebel; Christine Schiltz; Bruno Rossion

2007-01-01

38

Brain organization and sleep function  

Microsoft Academic Search

A view of brain organization and sleep function is presented. Sleep is hypothesized to begin at the neuronal group level. Sleep results in the use and thus maintenance, of synapses that are insufficiently stimulated during wakefulness thereby serving to preserve a constancy of a synaptic superstructure. It is further hypothesized that sleep at the neuronal group level is regulated by

James M. Krueger; Ferenc Obál; Levente Kapás; Jidong Fang

1995-01-01

39

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

40

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.

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

2013-01-01

41

Functional modules of the brain.  

PubMed

Building on the view of massive modularity, a number of generalized assumptions lead to an entirely new concept of functional brain modules. In contrast to the nerve centers usually considered to be active in the brain, these modules, called symbions, are non-localized, non-hierarchical, and based on subcellular molecular mechanisms rather than on neurons. They act according to local rules that may be fundamentally nonlinear, potentially leading to strong interdependencies between parallel inputs, and they interact by information, not by force. The existence of inner states, feedback loops, internal models, and information encoding provide the basis for a higher complexity than is usually assumed in neuroscience. A map of the symbion world, showing functional rather than physical localization, can be used to illustrate symbion interaction patterns. Perceptual constancy, sensory illusions, visual cognition, and eye-hand coordination are used as examples of what can be explained by using the new theory. PMID:12051988

Philipson, Lars

2002-03-01

42

Nicotine increases brain functional network efficiency.  

PubMed

Despite the use of cholinergic therapies in Alzheimer's disease and the development of cholinergic strategies for schizophrenia, relatively little is known about how the system modulates the connectivity and structure of large-scale brain networks. To better understand how nicotinic cholinergic systems alter these networks, this study examined the effects of nicotine on measures of whole-brain network communication efficiency. Resting state fMRI was acquired from fifteen healthy subjects before and after the application of nicotine or placebo transdermal patches in a single blind, crossover design. Data, which were previously examined for default network activity, were analyzed with network topology techniques to measure changes in the communication efficiency of whole-brain networks. Nicotine significantly increased local efficiency, a parameter that estimates the network's tolerance to local errors in communication. Nicotine also significantly enhanced the regional efficiency of limbic and paralimbic areas of the brain, areas which are especially altered in diseases such as Alzheimer's disease and schizophrenia. These changes in network topology may be one mechanism by which cholinergic therapies improve brain function. PMID:22796985

Wylie, Korey P; Rojas, Donald C; Tanabe, Jody; Martin, Laura F; Tregellas, Jason R

2012-10-15

43

Nicotine Increases Brain Functional Network Efficiency  

PubMed Central

Despite the use of cholinergic therapies in Alzheimer’s disease and the development of cholinergic strategies for schizophrenia, relatively little is known about how the system modulates the connectivity and structure of large-scale brain networks. To better understand how nicotinic cholinergic systems alter these networks, this study examined the effects of nicotine on measures of whole-brain network communication efficiency. Resting-state fMRI was acquired from fifteen healthy subjects before and after the application of nicotine or placebo transdermal patches in a single blind, crossover design. Data, which were previously examined for default network activity, were analyzed with network topology techniques to measure changes in the communication efficiency of whole-brain networks. Nicotine significantly increased local efficiency, a parameter that estimates the network’s tolerance to local errors in communication. Nicotine also significantly enhanced the regional efficiency of limbic and paralimbic areas of the brain, areas which are especially altered in diseases such as Alzheimer’s disease and schizophrenia. These changes in network topology may be one mechanism by which cholinergic therapies improve brain function.

Wylie, Korey P.; Rojas, Donald C.; Tanabe, Jody; Martin, Laura F.; Tregellas, Jason R.

2012-01-01

44

From connections to function: the mouse brain connectome atlas.  

PubMed

Mapping synaptic connections and projections is crucial for understanding brain dynamics and function. In a recent issue of Nature, Oh et al. present a wiring diagram of the whole mouse brain, where standardized labeling, tracing, and imaging of axonal connections reveal new details in the network organization of neuronal connectivity. PMID:24813604

Sporns, Olaf; Bullmore, Edward T

2014-05-01

45

Structural and functional brain imaging in schizophrenia.  

PubMed Central

We present an evaluation of the contribution of structural and functional brain imaging to our understanding of schizophrenia. Methodological influences on the validity of the data generated by these new technologies include problems with measurement and clinical and anatomic heterogeneity. These considerations greatly affect the interpretation of the data generated by these technologies. Work in these fields to date, however, has produced strong evidence which suggests that schizophrenia is a disease which involves abnormalities in the structure and function of many brain areas. Structural brain imaging studies of schizophrenia using computed tomography (CT) and magnetic resonance imaging (MRI) are reviewed and their contribution to current theories of the pathogenesis of schizophrenia are discussed. Positron emission tomography (PET) studies of brain metabolic activity and dopamine receptor binding in schizophrenia are summarized and the critical questions raised by these studies are outlined. Future studies in these fields have the potential to yield critical insights into the pathophysiology of schizophrenia; new directions for studies of schizophrenia using these technologies are identified.

Cleghorn, J M; Zipursky, R B; List, S J

1991-01-01

46

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

47

David's Understanding of Functions and Periodicity  

ERIC Educational Resources Information Center

This is a study of David, a senior enrolled in a high school precalculus course. David's understandings of functions and periodicity was explored, through clinical interviews and contextualized through classroom observations. Although David's precalculus class was traditional his understanding of periodic functions was unconventional David engaged…

Gerson, Hope

2008-01-01

48

Sex Hormones, Brain Development and Brain Function.  

National Technical Information Service (NTIS)

The view that gonadal hormones exert a double action on the central nervous system--inductive during development and excitatory in the adult--allows a direct comparison between the brain and genital tract as target organs for these hormones. In both cases...

G. W. Harris

1964-01-01

49

A default mode of brain function  

Microsoft Academic Search

A baseline or control state is fundamental to the understanding of most complex systems. Defining a baseline state in the human brain, arguably our most complex system, poses a particular challenge. Many suspect that left unconstrained, its activity will vary unpredictably. Despite this prediction we identify a baseline state of the normal adult human brain in terms of the brain

Marcus E. Raichle; Ann Mary MacLeod; Abraham Z. Snyder; William J. Powers; Debra A. Gusnard; Gordon L. Shulman

2001-01-01

50

The functional neuroanatomy of working memory: Contributions of human brain lesion studies  

Microsoft Academic Search

Studies of patients with focal brain lesions remain critical components of research programs attempting to understand human brain function. Whereas functional imaging typically reveals activity in distributed brain regions that are involved in a task, lesion studies can define which of these brain regions are necessary for a cognitive process. Further, lesion studies are less critical regarding the selection of

N. G. Müller; R. T. Knight

2006-01-01

51

Using Adaptive Dynamic Programming to Understand and Replicate Brain Intelligence: the Next Level Design  

Microsoft Academic Search

Since the 1960s I proposed that we could understand and replicate the highest\\u000alevel of intelligence seen in the brain, by building ever more capable and\\u000ageneral systems for adaptive dynamic programming (ADP), which is like\\u000areinforcement learning but based on approximating the Bellman equation and\\u000aallowing the controller to know its utility function. Growing empirical\\u000aevidence on the brain

Paul J. Werbos

2006-01-01

52

Using ADP to Understand and Replicate Brain Intelligence: The Next Level Design?  

Microsoft Academic Search

Since the 1960’s I proposed that we could understand and replicate the highest level of intelligence seen in the brain, by\\u000a building ever more capable and general systems for adaptive dynamic programming (ADP) – like “reinforcement learning” but\\u000a based on approximating the Bellman equation and allowing the controller to know its utility function. Growing empirical evidence\\u000a on the brain supports

Paul Werbos

53

Brain foods: the effects of nutrients on brain function  

Microsoft Academic Search

It has long been suspected that the relative abundance of specific nutrients can affect cognitive processes and emotions. Newly described influences of dietary factors on neuronal function and synaptic plasticity have revealed some of the vital mechanisms that are responsible for the action of diet on brain health and mental function. Several gut hormones that can enter the brain, or

Fernando Gómez-Pinilla

2008-01-01

54

Chemogenetic tools to interrogate brain functions.  

PubMed

Elucidating the roles of neuronal cell types for physiology and behavior is essential for understanding brain functions. Perturbation of neuron electrical activity can be used to probe the causal relationship between neuronal cell types and behavior. New genetically encoded neuron perturbation tools have been developed for remotely controlling neuron function using small molecules that activate engineered receptors that can be targeted to cell types using genetic methods. Here we describe recent progress for approaches using genetically engineered receptors that selectively interact with small molecules. Called "chemogenetics," receptors with diverse cellular functions have been developed that facilitate the selective pharmacological control over a diverse range of cell-signaling processes, including electrical activity, for molecularly defined cell types. These tools have revealed remarkably specific behavioral physiological influences for molecularly defined cell types that are often intermingled with populations having different or even opposite functions. PMID:25002280

Sternson, Scott M; Roth, Bryan L

2014-07-01

55

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

56

Functional Brain Networks in Schizophrenia: A Review  

PubMed Central

Functional magnetic resonance imaging (fMRI) has become a major technique for studying cognitive function and its disruption in mental illness, including schizophrenia. The major proportion of imaging studies focused primarily upon identifying regions which hemodynamic response amplitudes covary with particular stimuli and differentiate between patient and control groups. In addition to such amplitude based comparisons, one can estimate temporal correlations and compute maps of functional connectivity between regions which include the variance associated with event-related responses as well as intrinsic fluctuations of hemodynamic activity. Functional connectivity maps can be computed by correlating all voxels with a seed region when a spatial prior is available. An alternative are multivariate decompositions such as independent component analysis (ICA) which extract multiple components, each of which is a spatially distinct map of voxels with a common time course. Recent work has shown that these networks are pervasive in relaxed resting and during task performance and hence provide robust measures of intact and disturbed brain activity. This in turn bears the prospect of yielding biomarkers for schizophrenia, which can be described both in terms of disrupted local processing as well as altered global connectivity between large-scale networks. In this review we will summarize functional connectivity measures with a focus upon work with ICA and discuss the meaning of intrinsic fluctuations. In addition, examples of how brain networks have been used for classification of disease will be shown. We present work with functional network connectivity, an approach that enables the evaluation of the interplay between multiple networks and how they are affected in disease. We conclude by discussing new variants of ICA for extracting maximally group discriminative networks from data. In summary, it is clear that identification of brain networks and their inter-relationships with fMRI has great potential to improve our understanding of schizophrenia.

Calhoun, Vince D.; Eichele, Tom; Pearlson, Godfrey

2009-01-01

57

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

58

Functional connectivity in the normal and injured brain.  

PubMed

The brain is neither uniform nor composed of similar modules but is rather a mosaic of different and highly interconnected regions. Accordingly, knowledge of functional connectivity between brain regions is crucial to understanding perception, cognition, and behavior. Functional connectivity methods estimate similarities between activity recorded in different regions of the brain. They are often applied to resting state activity, thus providing measures that are by nature task independent. The spatial patterns revealed by functional connectivity are not only shaped by the underlying anatomical structure of the brain but also partially depend on the history of task-driven coactivations. Inter-subject differences in functional connectivity may, at least to some degree, underlie variability observed in task performance across healthy subjects and in behavioral impairments in neurological patients. In this respect, recent studies have demonstrated that behavioral deficits in patients with brain injury are not only due to local tissue damage but also due to altered functional connectivity among structurally intact regions connected to the damaged site. Studies based on functional connectivity have the potential to advance basic understanding of how brain lesions induce neuropsychological syndromes. Furthermore, they may eventually suggest improved rehabilitation strategies for patients with brain injury, through the design of individualized treatment and recovery protocols. PMID:23064084

Gillebert, Céline R; Mantini, Dante

2013-10-01

59

Angiogenesis, neurogenesis and brain recovery of function following injury  

PubMed Central

Traumatic brain injury and stroke are major causes of mortality and morbidity worldwide. Unfortunately, almost all phase-III neuroprotective clinical trials for stroke and traumatic brain injury have shown no benefits; this has raised concerns regarding neuroprotective strategy alone as a therapy for acute brain injuries. There is therefore a compelling need to develop treatments that promote the repair and regeneration of injured brain tissue and functional recovery. Recent findings suggest that strategies to enhance angiogenesis and neurogenesis for brain injuries may provide promising opportunities to improve clinical outcomes during brain functional recovery. This article reviews current data on angiogenesis and neurogenesis in the adult brain after stroke and traumatic brain injury. Select cell-based and pharmacological therapies that promote angiogenesis and neurogenesis designed to restore neurological function after brain injuries are described. These findings highlight the need for a better understanding of injury- and therapy-induced angiogenesis and neurogenesis in the adult and suggest that the manipulation of endogenous neural precursors and endothelial cells is a potential therapy for brain injury.

Xiong, Ye; Mahmood, Asim; Chopp, Michael

2010-01-01

60

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

61

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.

Perrey, Stephane

2013-01-01

62

Brain function assessment in different conscious states  

PubMed Central

Background The study of brain functioning is a major challenge in neuroscience fields as human brain has a dynamic and ever changing information processing. Case is worsened with conditions where brain undergoes major changes in so-called different conscious states. Even though the exact definition of consciousness is a hard one, there are certain conditions where the descriptions have reached a consensus. The sleep and the anesthesia are different conditions which are separable from each other and also from wakefulness. The aim of our group has been to tackle the issue of brain functioning with setting up similar research conditions for these three conscious states. Methods In order to achieve this goal we have designed an auditory stimulation battery with changing conditions to be recorded during a 40 channel EEG polygraph (Nuamps) session. The stimuli (modified mismatch, auditory evoked etc.) have been administered both in the operation room and the sleep lab via Embedded Interactive Stimulus Unit which was developed in our lab. The overall study has provided some results for three domains of consciousness. In order to be able to monitor the changes we have incorporated Bispectral Index Monitoring to both sleep and anesthesia conditions. Results The first stage results have provided a basic understanding in these altered states such that auditory stimuli have been successfully processed in both light and deep sleep stages. The anesthesia provides a sudden change in brain responsiveness; therefore a dosage dependent anesthetic administration has proved to be useful. The auditory processing was exemplified targeting N1 wave, with a thorough analysis from spectrogram to sLORETA. The frequency components were observed to be shifting throughout the stages. The propofol administration and the deeper sleep stages both resulted in the decreasing of N1 component. The sLORETA revealed similar activity at BA7 in sleep (BIS 70) and target propofol concentration of 1.2 µg/mL. Conclusions The current study utilized similar stimulation and recording system and incorporated BIS dependent values to validate a common approach to sleep and anesthesia. Accordingly the brain has a complex behavior pattern, dynamically changing its responsiveness in accordance with stimulations and states.

2010-01-01

63

Brain death and the historical understanding of bioethics.  

PubMed

In a 1968 Report, the Ad Hoc Committee of the Harvard Medical School to Examine the Definition of Brain Death promulgated influential criteria for the idea and practice known as "brain death." Before and since the Committee met, brain death has been a focal point of visions and nightmares of medical progress, purpose, and moral authority. Critics of the Committee felt it was deaf to apparently central moral considerations and focused on the self-serving purpose of expanding transplantation. Historical characterizations of the uses and meanings of brain death and the work of the Committee have tended to echo these themes, which means also generally repeating a widely held bioethical self-understanding of how the field appeared-that is, as a necessary antidote of moral expertise. This paper looks at the Committee and finds that historical depictions of it have been skewed by such a bioethical agenda. Entertaining different possibilities as to the motives and historical circumstances behind the Report it famously produced may point to not only different histories of the Committee, but also different perspectives on the historical legacy and role of bioethics as a discourse for addressing anxieties about medicine. PMID:12938717

Belkin, Gary S

2003-07-01

64

Effect of disease and recovery on functional anatomy in brain tumor patients: insights from functional MRI and diffusion tensor imaging  

PubMed Central

Patients with brain tumors provide a unique opportunity to understand functional brain plasticity. Using advanced imaging techniques, such as functional MRI and diffusion tensor imaging, we have gained tremendous knowledge of brain tumor behavior, transformation, infiltration and destruction of nearby structures. Using these advanced techniques as an adjunct with more proven techniques, such as direct cortical stimulation, intraoperative navigation and advanced microsurgical techniques, we now are able to better formulate safer resection trajectories, perform larger resections at reduced risk and better counsel patients and their families about possible complications. Brain mapping in patients with brain tumors and other lesions has shown us that the old idea of fixed function of the adult cerebral cortex is not entirely true. Improving care for patients with brain lesions in the future will depend on better understanding of the functional organization and plasticity of the adult brain. Advanced noninvasive brain imaging will undoubtedly play a role in advancing this understanding.

Abd-El-Barr, Muhammad M; Saleh, Emam; Huang, Raymond Y; Golby, Alexandra J

2014-01-01

65

Multistability and metastability: understanding dynamic coordination in the brain  

PubMed Central

Multistable coordination dynamics exists at many levels, from multifunctional neural circuits in vertebrates and invertebrates to large-scale neural circuitry in humans. Moreover, multistability spans (at least) the domains of action and perception, and has been found to place constraints upon, even dictating the nature of, intentional change and the skill-learning process. This paper reviews some of the key evidence for multistability in the aforementioned areas, and illustrates how it has been measured, modelled and theoretically understood. It then suggests how multistability—when combined with essential aspects of coordination dynamics such as instability, transitions and (especially) metastability—provides a platform for understanding coupling and the creative dynamics of complex goal-directed systems, including the brain and the brain–behaviour relation.

Kelso, J. A. Scott

2012-01-01

66

Insulin action in brain regulates systemic metabolism and brain function.  

PubMed

Insulin receptors, as well as IGF-1 receptors and their postreceptor signaling partners, are distributed throughout the brain. Insulin acts on these receptors to modulate peripheral metabolism, including regulation of appetite, reproductive function, body temperature, white fat mass, hepatic glucose output, and response to hypoglycemia. Insulin signaling also modulates neurotransmitter channel activity, brain cholesterol synthesis, and mitochondrial function. Disruption of insulin action in the brain leads to impairment of neuronal function and synaptogenesis. In addition, insulin signaling modulates phosphorylation of tau protein, an early component in the development of Alzheimer disease. Thus, alterations in insulin action in the brain can contribute to metabolic syndrome, and the development of mood disorders and neurodegenerative diseases. PMID:24931034

Kleinridders, André; Ferris, Heather A; Cai, Weikang; Kahn, C Ronald

2014-07-01

67

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.

Tian, Tian Siva

2010-01-01

68

The development of Human Functional Brain Networks  

PubMed Central

Recent advances in MRI technology have enabled precise measurements of correlated activity throughout the brain, leading to the first comprehensive descriptions of functional brain networks in humans. This article reviews the growing literature on the development of functional networks, from infancy through adolescence, as measured by resting state functional connectivity MRI. We note several limitations of traditional approaches to describing brain networks, and describe a powerful framework for analyzing networks, called graph theory. We argue that characterization of the development of brain systems (e.g. the default mode network) should be comprehensive, considering not only relationships within a given system, but also how these relationships are situated within wider network contexts. We note that, despite substantial reorganization of functional connectivity, several large-scale network properties appear to be preserved across development, suggesting that functional brain networks, even in children, are organized in manners similar to other complex systems.

Power, Jonathan D; Fair, Damien A; Schlaggar, Bradley L

2010-01-01

69

Understanding Transformations of Periodic Functions through Art.  

ERIC Educational Resources Information Center

Presents an interdisciplinary project for precalculus classes that allows students to increase their understanding of the mathematics of transformations of periodic functions and helps them see mathematics in art. Uses an applet that produces high-quality graphs and real works of art by using combinations of transformations of the sine and cosine…

Miller, Syrilda

2001-01-01

70

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.

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

2010-01-01

71

The gravitational field and brain function  

NASA Astrophysics Data System (ADS)

The frontal cortex is recognized as the highest adaptive control center of the human brain. The principle of the ``frontalization'' of human brain function offers new possibilities for brain research in space. There is evolutionary and experimental evidence indicating the validity of the principle, including it's role in nervous response to gravitational stimulation. The gravitational field is considered here as one of the more constant and comprehensive factors acting on brain evolution, which has undergone some successive crucial steps: ``encephalization'', ``corticalization'', ``lateralization'' and ``frontalization''. The dominating effects of electrical responses from the frontal cortex have been discovered 1) in experiments under gravitational stimulus; and 2) in processes potentially relating to gravitational adaptation, such as memory and learning, sensory information processing, motor programing, and brain state control. A brain research experiment during space flight is suggested to test the role of the frontal cortex in space adaptation and it's potentiality in brain control.

Mei, Lei; Zhou, Chuan-Dai; Lan, Jing-Quan; Wang, Zhi-Ging; Wu, Wen-Can; Xue, Xin-Min

72

Information theoretic approaches to understanding circuit function  

PubMed Central

The analysis of stimulus/response patterns using information theoretic approaches requires the full probability distribution of stimuli and response. Recent progress in using information-based tools to understand circuit function has advanced understanding of neural coding at the single cell and population level. In advances over traditional reverse correlation approaches, the determination of receptive fields using information as a metric has allowed novel insights into stimulus representation and transformation. The application of maximum entropy methods to population codes has opened a rich exploration of the internal structure of these codes, revealing stimulus-driven functional connectivity. We speculate about the prospects and limitations of information as a general tool for dissecting neural circuits and relating their structure and function.

Shea-Brown, Eric; Barreiro, Andrea

2014-01-01

73

Determination of Vascular Dementia Brain in Distinct Frequency Bands with Whole Brain Functional Connectivity Patterns  

PubMed Central

Recent studies have shown that multivariate pattern analysis (MVPA) can be useful for distinguishing brain disorders into categories. Such analyses can substantially enrich and facilitate clinical diagnoses. Using MPVA methods, whole brain functional networks, especially those derived using different frequency windows, can be applied to detect brain states. We constructed whole brain functional networks for groups of vascular dementia (VaD) patients and controls using resting state BOLD-fMRI (rsfMRI) data from three frequency bands - slow-5 (0.01?0.027 Hz), slow-4 (0.027?0.073 Hz), and whole-band (0.01?0.073 Hz). Then we used the support vector machine (SVM), a type of MVPA classifier, to determine the patterns of functional connectivity. Our results showed that the brain functional networks derived from rsfMRI data (19 VaD patients and 20 controls) in these three frequency bands appear to reflect neurobiological changes in VaD patients. Such differences could be used to differentiate the brain states of VaD patients from those of healthy individuals. We also found that the functional connectivity patterns of the human brain in the three frequency bands differed, as did their ability to differentiate brain states. Specifically, the ability of the functional connectivity pattern to differentiate VaD brains from healthy ones was more efficient in the slow-5 (0.01?0.027 Hz) band than in the other two frequency bands. Our findings suggest that the MVPA approach could be used to detect abnormalities in the functional connectivity of VaD patients in distinct frequency bands. Identifying such abnormalities may contribute to our understanding of the pathogenesis of VaD.

Zhang, Delong; Liu, Bo; Chen, Jun; Peng, Xiaoling; Liu, Xian; Fan, Yuanyuan; Liu, Ming; Huang, Ruiwang

2013-01-01

74

Surface mapping brain function on 3D models  

Microsoft Academic Search

A flexible graphics system for displaying functional and anatomic data on arbitrary collections of surfaces on or within the brain is presented. The system makes it possible to show complex, convoluted surfaces with the shading cues necessary to understand their shapes; to vary viewpoint, object position, illumination, and perspective easily; to show multiple-objects in one view, with or without transparency,

Bradley A. Payne; Arthur W. Toga

1990-01-01

75

Localizing Visual Function in the Brain.  

National Technical Information Service (NTIS)

A three day meeting, held in Rochester, discussed 'Localizing Visual Function in the Brain'. The meeting consisted of presentations by 15 prominent scientists of topics including; the anatomy of modular connections in the primate visual system, computatio...

W. H. Merigan

1992-01-01

76

Early Brain Stimulation May Help Stroke Survivors Recover Language Function  

MedlinePLUS

Early brain stimulation may help stroke survivors recover language function June 27, 2013 Study Highlights: Non-invasive brain stimulation ... Brain Stimulation copyright American Heart Association Infographic - Thiel-Brain Stimulation copyright American Heart Association Download (311.8 ...

77

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

PubMed

The introduction and development, over the last three decades, of magnetic resonance (MR) imaging and MR spectroscopy technology for in vivo studies of the human brain represents a truly remarkable achievement, with enormous scientific and clinical ramifications. These effectively non-invasive techniques allow for studies of the anatomy, the function and the metabolism of the living human brain. They have allowed for new understandings of how the healthy brain works and have provided insights into the mechanisms underlying multiple disease processes which affect the brain. Different MR techniques have been developed for studying anatomy, function and metabolism. The primary focus of this review is to describe these different methodologies and to briefly review how they are being employed to more fully appreciate the intricacies associated with the organ, which most distinctly differentiates the human species from the other animal forms on earth. PMID:16568243

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

2006-05-01

78

Exercise Benefits Brain Function: The Monoamine Connection  

PubMed Central

The beneficial effects of exercise on brain function have been demonstrated in animal models and in a growing number of clinical studies on humans. There are multiple mechanisms that account for the brain-enhancing effects of exercise, including neuroinflammation, vascularization, antioxidation, energy adaptation, and regulations on neurotrophic factors and neurotransmitters. Dopamine (DA), noradrenaline (NE), and serotonin (5-HT) are the three major monoamine neurotransmitters that are known to be modulated by exercise. This review focuses on how these three neurotransmitters contribute to exercise affecting brain function and how it can work against neurological disorders.

Lin, Tzu-Wei; Kuo, Yu-Min

2013-01-01

79

Scale-free brain functional networks  

Microsoft Academic Search

Functional magnetic resonance imaging is used to extract functional networks connecting correlated human brain sites. Analysis of the resulting networks in different tasks shows that (a) the distribution of functional connections, and the probability of finding a link versus distance are both scale-free, (b) the characteristic path length is small and comparable with those of equivalent random networks, and (c)

Neural Darwinism. Basic Books; G. A. Cecchi; M. Baliki; A. V. Apkarian

1987-01-01

80

Understanding human functioning using graphical models  

PubMed Central

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 functioning. The objective of our paper therefore is to explore how graphical models can be used in the study of ICF data for a range of applications. Methods We show the applicability of graphical models on ICF data for different tasks: Visualization of the dependence structure of the data set, dimension reduction and comparison of subpopulations. Moreover, we further developed and applied recent findings in causal inference using graphical models to estimate bounds on intervention effects in an observational study with many variables and without knowing the underlying causal structure. Results In each field, graphical models could be applied giving results of high face-validity. In particular, graphical models could be used for visualization of functioning in patients with spinal cord injury. The resulting graph consisted of several connected components which can be used for dimension reduction. Moreover, we found that the differences in the dependence structures between subpopulations were relevant and could be systematically analyzed using graphical models. Finally, when estimating bounds on causal effects of ICF categories on general health perceptions among patients with chronic health conditions, we found that the five ICF categories that showed the strongest effect were plausible. Conclusions Graphical Models are a flexible tool and lend themselves for a wide range of applications. In particular, studies involving ICF data seem to be suited for analysis using graphical models.

2010-01-01

81

Vitamins Deficiencies and Brain Function  

Microsoft Academic Search

\\u000a The consequences of malnutrition on the central nervous system are diverse and depend to a significant extent on the stage\\u000a of development or maturity of the brain as well as on the severity of the nutritional deficiency. For example, vitamin deficiencies\\u000a result in a wide range of neuropathology and neuropsychiatric symptomatology depending upon the nature and extent of the vitamin

Chantal Bémeur; Jane A. Montgomery; Roger F. Butterworth

82

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

83

Human brain functional MRI and DTI visualization with virtual reality.  

PubMed

Magnetic resonance diffusion tensor imaging (DTI) and functional MRI (fMRI) are two active research areas in neuroimaging. DTI is sensitive to the anisotropic diffusion of water exerted by its macromolecular environment and has been shown useful in characterizing structures of ordered tissues such as the brain white matter, myocardium, and cartilage. The diffusion tensor provides two new types of information of water diffusion: the magnitude and the spatial orientation of water diffusivity inside the tissue. This information has been used for white matter fiber tracking to review physical neuronal pathways inside the brain. Functional MRI measures brain activations using the hemodynamic response. The statistically derived activation map corresponds to human brain functional activities caused by neuronal activities. The combination of these two methods provides a new way to understand human brain from the anatomical neuronal fiber connectivity to functional activities between different brain regions. In this study, virtual reality (VR) based MR DTI and fMRI visualization with high resolution anatomical image segmentation and registration, ROI definition and neuronal white matter fiber tractography visualization and fMRI activation map integration is proposed. Rationale and methods for producing and distributing stereoscopic videos are also discussed. PMID:23256049

Chen, Bin; Moreland, John; Zhang, Jingyu

2011-12-01

84

Affective neuroscience of the emotional BrainMind: evolutionary perspectives and implications for understanding depression  

PubMed Central

Cross-species affective neuroscience studies confirm that primary-process emotional feelings are organized within primitive subcortical regions of the brain that are anatomically, neurochemically, and functionally homologous in all mammals that have been studied. Emotional feelings (affects) are intrinsic values that inform animals how they are faring in the quest to survive. The various positive affects indicate that animals are returning to “comfort zones” that support survival, and negative affects reflect “discomfort zones” that indicate that animals are in situations that may impair survival. They are ancestral tools for living - evolutionary memories of such importance that they were coded into the genome in rough form (as primary brain processes), which are refined by basic learning mechanisms (secondary processes) as well as by higher-order cognitions/thoughts (tertiary processes). To understand why depression feels horrible, we must fathom the affective infrastructure of the mammalian brain. Advances in our understanding of the nature of primary-process emotional affects can promote the development of better preclinical models of psychiatric disorders and thereby also allow clinicians new and useful ways to understand the foundational aspects of their clients' problems. These networks are of clear importance for understanding psychiatric disorders and advancing psychiatric practice.

Panksepp, Jaak

2010-01-01

85

Disrupted Functional Brain Connectivity in Partial Epilepsy: A Resting-State fMRI Study  

Microsoft Academic Search

Examining the spontaneous activity to understand the neural mechanism of brain disorder is a focus in recent resting-state fMRI. In the current study, to investigate the alteration of brain functional connectivity in partial epilepsy in a systematical way, two levels of analyses (functional connectivity analysis within resting state networks (RSNs) and functional network connectivity (FNC) analysis) were carried out on

Cheng Luo; Chuan Qiu; Zhiwei Guo; Jiajia Fang; Qifu Li; Xu Lei; Yang Xia; Yongxiu Lai; Qiyong Gong; Dong Zhou; Dezhong Yao

2012-01-01

86

Metabolism and functions of copper in brain.  

PubMed

Copper is an important trace element that is required for essential enzymes. However, due to its redox activity, copper can also lead to the generation of toxic reactive oxygen species. Therefore, cellular uptake, storage as well as export of copper have to be tightly regulated in order to guarantee sufficient copper supply for the synthesis of copper-containing enzymes but also to prevent copper-induced oxidative stress. In brain, copper is of importance for normal development. In addition, both copper deficiency as well as excess of copper can seriously affect brain functions. Therefore, this organ possesses ample mechanisms to regulate its copper metabolism. In brain, astrocytes are considered as important regulators of copper homeostasis. Impairments of homeostatic mechanisms in brain copper metabolism have been associated with neurodegeneration in human disorders such as Menkes disease, Wilson's disease and Alzheimer's disease. This review article will summarize the biological functions of copper in the brain and will describe the current knowledge on the mechanisms involved in copper transport, storage and export of brain cells. The role of copper in diseases that have been connected with disturbances in brain copper homeostasis will also be discussed. PMID:24440710

Scheiber, Ivo F; Mercer, Julian F B; Dringen, Ralf

2014-05-01

87

Lead poisoning and brain cell function  

SciTech Connect

Exposure to excessive amounts of inorganic lead during the toddler years may produce lasting adverse effects upon brain function. Maximal ingestion of lead occurs at an age when major changes are occurring in the density of brain synaptic connections. The developmental reorganization of synapses is, in part, mediated by protein kinases, and these enzymes are particularly sensitive to stimulation by lead. By inappropriately activating specific protein kinases, lead poisoning may disrupt the development of neural networks without producing overt pathological alterations. The blood-brain barrier is another potential vulnerable site for the neurotoxic action of lead. protein kinases appear to regulate the development of brain capillaries and the expression of the blood-brain barrier properties. Stimulation of protein kinase by lead may disrupt barrier development and alter the precise regulation of the neuronal environment that is required for normal brain function. Together, these findings suggest that the sensitivity of protein kinases to lead may in part underlie the brain dysfunction observed in children poisoned by this toxicant.

Goldstein, G.W. (Johns Hopkins School of Medicine, Baltimore, MD (USA) Kennedy Institute, Baltimore, MD (USA))

1990-11-01

88

Understanding a Brain-Based Approach to Learning and Teaching.  

ERIC Educational Resources Information Center

Offers 12 principles as a general foundation for brain-based learning, including (1) the brain is a parallel processor; (2) learning engages the entire physiology; (3) the search for meaning is innate and occurs through patterning; (5) emotions are critical to patterning; (6) every brain simultaneously perceives and creates parts and wholes; and…

Caine, Renate Nummela; Caine, Geoffrey

1990-01-01

89

Toward discovery science of human brain function.  

PubMed

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 during rest reveals large-amplitude spontaneous low-frequency (<0.1 Hz) fluctuations in the fMRI signal that are temporally correlated across functionally related areas. Referred to as functional connectivity, these correlations yield detailed maps of complex neural systems, collectively constituting an individual's "functional connectome." Reproducibility across datasets and individuals suggests the functional connectome has a common architecture, yet each individual's functional connectome exhibits unique features, with stable, meaningful interindividual differences in connectivity patterns and strengths. Comprehensive mapping of the functional connectome, and its subsequent exploitation to discern genetic influences and brain-behavior relationships, will require multicenter collaborative datasets. Here we initiate this endeavor by gathering R-fMRI data from 1,414 volunteers collected independently at 35 international centers. We demonstrate a universal architecture of positive and negative functional connections, as well as consistent loci of inter-individual variability. Age and sex emerged as significant determinants. These results demonstrate that independent R-fMRI datasets can be aggregated and shared. High-throughput R-fMRI can provide quantitative phenotypes for molecular genetic studies and biomarkers of developmental and pathological processes in the brain. To initiate discovery science of brain function, the 1000 Functional Connectomes Project dataset is freely accessible at www.nitrc.org/projects/fcon_1000/. PMID:20176931

Biswal, Bharat B; Mennes, Maarten; Zuo, Xi-Nian; Gohel, Suril; Kelly, Clare; Smith, Steve M; Beckmann, Christian F; Adelstein, Jonathan S; Buckner, Randy L; Colcombe, Stan; Dogonowski, Anne-Marie; Ernst, Monique; Fair, Damien; Hampson, Michelle; Hoptman, Matthew J; Hyde, James S; Kiviniemi, Vesa J; Kötter, Rolf; Li, Shi-Jiang; Lin, Ching-Po; Lowe, Mark J; Mackay, Clare; Madden, David J; Madsen, Kristoffer H; Margulies, Daniel S; Mayberg, Helen S; McMahon, Katie; Monk, Christopher S; Mostofsky, Stewart H; Nagel, Bonnie J; Pekar, James J; Peltier, Scott J; Petersen, Steven E; Riedl, Valentin; Rombouts, Serge A R B; Rypma, Bart; Schlaggar, Bradley L; Schmidt, Sein; Seidler, Rachael D; Siegle, Greg J; Sorg, Christian; Teng, Gao-Jun; Veijola, Juha; Villringer, Arno; Walter, Martin; Wang, Lihong; Weng, Xu-Chu; Whitfield-Gabrieli, Susan; Williamson, Peter; Windischberger, Christian; Zang, Yu-Feng; Zhang, Hong-Ying; Castellanos, F Xavier; Milham, Michael P

2010-03-01

90

IMPLICATION OF ATP RECEPTORS IN BRAIN FUNCTIONS  

Microsoft Academic Search

The possible implication of P2-purinoceptors in brain functions is reviewed. Involvement of P2-purinoceptors in memory and learning (Section 2) is suggested by ATP release from hippocampal slices [Wieraszko et al. (1989)Brain Res. 485, 244–250], induction of fast synaptic currents in cultured hippocampal neurons [Inoue et al. (1992a)Neurosci. Lett. 134, 294–299] and long-lasting enhancement of the population spikes [Wieraszko and Seyfried

KAZUHIDE INOUE; SCHUICHI KOIZUMI; SHINYA UENO

1996-01-01

91

Entropy changes in brain function.  

PubMed

The traditional way of analyzing brain electrical activity, on the basis of electroencephalography (EEG) records, relies mainly on visual inspection and years of training. Although it is quite useful, of course, one has to acknowledge its subjective nature that hardly allows for a systematic protocol. In the present work quantifiers based on information theory and wavelet transform are reviewed. The "relative wavelet energy" provides information about the relative energy associated with different frequency bands present in the EEG and their corresponding degree of importance. The "normalized total wavelet entropy" carries information about the degree of order-disorder associated with a multi-frequency signal response. Their application in the analysis and quantification of short duration EEG signals (event-related potentials) and epileptic EEG records are summarized. PMID:17234291

Rosso, Osvaldo A

2007-04-01

92

[Localization of language function in the brain].  

PubMed

Since the first report of an aphasic patient by Paul Broca, the localization of brain function has been disputed for 150 years. In lesion studies, double dissociation has been a key concept to show the localization of particular cognitive functions. The advancement of non-invasive brain imaging methods enables us to investigate the brain activities under well-controlled conditions, further promoting the studies on the localization of the cognitive functions, including language function. Brain imaging studies, together with subtraction and correlation analyses, have accumulated evidence that syntax, phonology, and sentence comprehension are separately processed by modules in different cortical regions. More specifically, it has been clarified that the module for syntax localizes in the left lateral premotor cortex and the opercular/triangular parts of the left inferior frontal gyrus. This modular structure further suggests that aphasia is interpreted as deficits in either syntactic or phonological processing. Therefore, the classical model of contrasting speech production and comprehension should be updated. According to theoretical linguistics, on the other hand, the recursive computation of syntactic structures is an essential feature of human language faculty. One direction of research would be to contrast human beings and animals for the abilities of processing symbolic sequences. Another direction is to clarify that the human brain is indeed specialized in language processing, which can be revealed by well-controlled language tasks and functional imaging techniques. Here we will review recent studies that demonstrate the existence of grammar center in the left frontal cortex. The future studies in the neuroscience of language will eventually elucidate the cortical localization of language function in a more precise way, i.e., what is really computed in the human brain. PMID:22147453

Miyashita, Hiroyuki; Sakai, Kuniyoshi L

2011-12-01

93

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.

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

94

Nicotine effects on brain function and functional connectivity in schizophrenia  

Microsoft Academic Search

BackgroundNicotine in tobacco smoke can improve functioning in multiple cognitive domains. High rates of smoking among schizophrenic patients may reflect an effort to remediate cognitive dysfunction. Our primary aim was to determine whether nicotine improves cognitive function by facilitating activation of brain regions mediating task performance or by facilitating functional connectivity.

Leslie K Jacobsen; D. Cyril D'Souza; W. Einar Mencl; Kenneth R Pugh; Pawel Skudlarski; John H Krystal

2004-01-01

95

Whole-Brain Functional Connectivity Identification of Functional Dyspepsia  

PubMed Central

Recent neuroimaging studies have shown local brain aberrations in functional dyspepsia (FD) patients, yet little attention has been paid to the whole-brain resting-state functional network abnormalities. The purpose of this study was to investigate whether FD disrupts the patterns of whole-brain networks and the abnormal functional connectivity could reflect the severity of the disease. The dysfunctional interactions between brain regions at rest were investigated in FD patients as compared with 40 age- and gender- matched healthy controls. Multivariate pattern analysis was used to evaluate the discriminative power of our results for classifying patients from controls. In our findings, the abnormal brain functional connections were mainly situated within or across the limbic/paralimbic system, the prefrontal cortex, the tempo-parietal areas and the visual cortex. About 96% of the subjects among the original dataset were correctly classified by a leave one-out cross-validation approach, and 88% accuracy was also validated in a replication dataset. The classification features were significantly associated with the patients’ dyspepsia symptoms, the self-rating depression scale and self-rating anxiety scale, but it was not correlated with duration of FD patients (p>0.05). Our results may indicate the effectiveness of the altered brain functional connections reflecting the disease pathophysiology underling FD. These dysfunctional connections may be the epiphenomena or causative agents of FD, which may be affected by clinical severity and its related emotional dimension of the disease rather than the clinical course.

Nan, Jiaofen; Liu, Jixin; Li, Guoying; Xiong, Shiwei; Yan, Xuemei; Yin, Qing; Zeng, Fang; von Deneen, Karen M.; Liang, Fanrong; Gong, Qiyong; Qin, Wei; Tian, Jie

2013-01-01

96

Values: Understanding Written Language and the Mind through Brain Biology.  

ERIC Educational Resources Information Center

Suggesting that neuroscience and the actualities of brain circuitry can provide guidance for what is misunderstood in writing education, namely, the role of subjectivity and values in the composing process, this paper argues that neuroscience provides corporeal evidence for the salience of particular brain structures and processes responsible for…

Brand, Alice G.

97

Understanding the Role of Neuroscience in Brain Based Products: A Guide for Educators and Consumers  

ERIC Educational Resources Information Center

The term "brain" based is often used to describe learning theories, principles, and products. Although there have been calls urging educators to be cautious in interpreting and using such material, consumers may find it challenging to understand the role of the brain and to discriminate among brain based products to determine which would be…

Sylvan, Lesley J.; Christodoulou, Joanna A.

2010-01-01

98

Reorganization of functional brain maps after exercise training: Importance of cerebellar–thalamic–cortical pathway  

Microsoft Academic Search

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

D. P. Holschneider; J. Yang; Y. Guo; J.-M. I. Maarek

2007-01-01

99

Changes in Connectivity after Visual Cortical Brain Damage Underlie Altered Visual Function  

ERIC Educational Resources Information Center

The full extent of the brain's ability to compensate for damage or changed experience is yet to be established. One question particularly important for evaluating and understanding rehabilitation following brain damage is whether recovery involves new and aberrant neural connections or whether any change in function is due to the functional

Bridge, Holly; Thomas, Owen; Jbabdi, Saad; Cowey, Alan

2008-01-01

100

Metabolism and functions of glutathione in brain  

Microsoft Academic Search

The tripeptide glutathione is the thiol compound present in the highest concentration in cells of all organs. Glutathione has many physiological functions including its involvement in the defense against reactive oxygen species. The cells of the human brain consume about 20% of the oxygen utilized by the body but constitute only 2% of the body weight. Consequently, reactive oxygen species

Ralf Dringen

2000-01-01

101

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.

Tsutsui, Kazuyoshi

2011-01-01

102

Regulatory RNAs in Brain Function and Disorders  

PubMed Central

Regulatory RNAs are being increasingly investigated in neurons, and important roles in brain function have been revealed. Regulatory RNAs are non-protein-coding RNAs (npcRNAs) that comprise a heterogeneous group of molecules, varying in size and mechanism of action. Regulatory RNAs often exert post-transcriptional control of gene expression, resulting in gene silencing or gene expression stimulation. Here, we review evidence that regulatory RNAs are implicated in neuronal development, differentiation, and plasticity. We will also discuss npcRNA dysregulation that may be involved in pathological states of the brain such as neurodevelopmental disorders, neurodegeneration, and epilepsy.

Iacoangeli, Anna; Bianchi, Riccardo; Tiedge, Henri

2012-01-01

103

Nuclear magnetic resonance imaging and spectroscopy of human brain function.  

PubMed Central

The techniques of in vivo magnetic resonance (MR) imaging and spectroscopy have been established over the past two decades. Recent applications of these methods to study human brain function have become a rapidly growing area of research. The development of methods using standard MR contrast agents within the cerebral vasculature has allowed measurements of regional cerebral blood volume (rCBV), which are activity dependent. Subsequent investigations linked the MR relaxation properties of brain tissue to blood oxygenation levels which are also modulated by consumption and blood flow (rCBF). These methods have allowed mapping of brain activity in human visual and motor cortex as well as in areas of the frontal lobe involved in language. The methods have high enough spatial and temporal sensitivity to be used in individual subjects. MR spectroscopy of proton and carbon-13 nuclei has been used to measure rates of glucose transport and metabolism in the human brain. The steady-state measurements of brain glucose concentrations can be used to monitor the glycolytic flux, whereas subsequent glucose metabolism--i.e., the flux into the cerebral glutamate pool--can be used to measure tricarboxylic acid cycle flux. Under visual stimulation the concentration of lactate in the visual cortex has been shown to increase by MR spectroscopy. This increase is compatible with an increase of anaerobic glycolysis under these conditions as earlier proposed from positron emission tomography studies. It is shown how MR spectroscopy can extend this understanding of brain metabolism. Images Fig. 1 Fig. 2 Fig. 3

Shulman, R G; Blamire, A M; Rothman, D L; McCarthy, G

1993-01-01

104

Functional Dissociation of Ongoing Oscillatory Brain States  

PubMed Central

The state of a neural assembly preceding an incoming stimulus is assumed to modulate the processing of subsequently presented stimuli. The nature of this state can differ with respect to the frequency of ongoing oscillatory activity. Oscillatory brain activity of specific frequency range such as alpha (8–12 Hz) and gamma (above 30 Hz) band oscillations are hypothesized to play a functional role in cognitive processing. Therefore, a selective modulation of this prestimulus activity could clarify the functional role of these prestimulus fluctuations. For this purpose, we adopted a novel non-invasive brain-computer-interface (BCI) strategy to selectively increase alpha or gamma band activity in the occipital cortex combined with an adaptive presentation of visual stimuli within specific brain states. During training, oscillatory brain activity was estimated online and fed back to the participants to enable a deliberate modulation of alpha or gamma band oscillations. Results revealed that volunteers selectively increased alpha and gamma frequency oscillations with a high level of specificity regarding frequency range and localization. At testing, alpha or gamma band activity was classified online and at defined levels of activity, visual objects embedded in noise were presented instantly and had to be detected by the volunteer. In experiment I, the effect of two levels of prestimulus gamma band activity on visual processing was examined. During phases of increased gamma band activity significantly more visual objects were detected. In experiment II, the effect was compared against increased levels of alpha band activity. An improvement of visual processing was only observed for enhanced gamma band activity. Both experiments demonstrate the specific functional role of prestimulus gamma band oscillations for perceptual processing. We propose that the BCI method permits the selective modulation of oscillatory activity and the direct assessment of behavioral consequences to test for functional dissociations of different oscillatory brain states.

Salari, Neda; Buchel, Christian; Rose, Michael

2012-01-01

105

Functional craniology and brain evolution: from paleontology to biomedicine  

PubMed Central

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.

Bruner, Emiliano; de la Cuetara, Jose Manuel; Masters, Michael; Amano, Hideki; Ogihara, Naomichi

2014-01-01

106

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.

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

107

Electroencephalographic imaging of higher brain function  

NASA Technical Reports Server (NTRS)

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.

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

1999-01-01

108

Reconceptualizing functional brain connectivity in autism from a developmental perspective  

PubMed Central

While there is almost universal agreement amongst researchers that autism is associated with alterations in brain connectivity, the precise nature of these alterations continues to be debated. Theoretical and empirical work is beginning to reveal that autism is associated with a complex functional phenotype characterized by both hypo- and hyper-connectivity of large-scale brain systems. It is not yet understood why such conflicting patterns of brain connectivity are observed across different studies, and the factors contributing to these heterogeneous findings have not been identified. Developmental changes in functional connectivity have received inadequate attention to date. We propose that discrepancies between findings of autism related hypo-connectivity and hyper-connectivity might be reconciled by taking developmental changes into account. We review neuroimaging studies of autism, with an emphasis on functional magnetic resonance imaging studies of intrinsic functional connectivity in children, adolescents and adults. The consistent pattern emerging across several studies is that while intrinsic functional connectivity in adolescents and adults with autism is generally reduced compared with age-matched controls, functional connectivity in younger children with the disorder appears to be increased. We suggest that by placing recent empirical findings within a developmental framework, and explicitly characterizing age and pubertal stage in future work, it may be possible to resolve conflicting findings of hypo- and hyper-connectivity in the extant literature and arrive at a more comprehensive understanding of the neurobiology of autism.

Uddin, Lucina Q.; Supekar, Kaustubh; Menon, Vinod

2013-01-01

109

Increases in Heart Disease Risk Factors May Decrease Brain Function  

MedlinePLUS

Increases in heart disease risk factors may decrease brain function May 02, 2013 Study Highlights: Increases in ... American Heart Association Infographic - H Joosten-Heart risks Brain function copyright American Heart Association Download (232.4 ...

110

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

111

Non-Invasive Brain-to-Brain Interface (BBI): Establishing Functional Links between Two Brains  

PubMed Central

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.

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

2013-01-01

112

Neural Darwinism: selection and reentrant signaling in higher brain function.  

PubMed

Variation and selection within neural populations play key roles in the development and function of the brain. In this article, I review a population theory of the nervous system aimed at understanding the significance of these processes. Since its original formulation in 1978, considerable evidence has accumulated to support this theory of neuronal group selection. Extensive neural modeling based on the theory has provided useful insights into several outstanding neurobiological problems including those concerned with integration of cortical function, sensorimotor control, and perceptually based behavior. PMID:8094962

Edelman, G M

1993-02-01

113

Approaches to Modelling the Dynamical Activity of Brain Function Based on the Electroencephalogram  

NASA Astrophysics Data System (ADS)

The brain is arguably the quintessential complex system as indicated by the patterns of behaviour it produces. Despite many decades of concentrated research efforts, we remain largely ignorant regarding the essential processes that regulate and define its function. While advances in functional neuroimaging have provided welcome windows into the coarse organisation of the neuronal networks that underlie a range of cognitive functions, they have largely ignored the fact that behaviour, and by inference brain function, unfolds dynamically. Modelling the brain's dynamics is therefore a critical step towards understanding the underlying mechanisms of its functioning. To date, models have concentrated on describing the sequential organisation of either abstract mental states (functionalism, hard AI) or the objectively measurable manifestations of the brain's ongoing activity (rCBF, EEG, MEG). While the former types of modelling approach may seem to better characterise brain function, they do so at the expense of not making a definite connection with the actual physical brain. Of the latter, only models of the EEG (or MEG) offer a temporal resolution well matched to the anticipated temporal scales of brain (mental processes) function. This chapter will outline the most pertinent of these modelling approaches, and illustrate, using the electrocortical model of Liley et al, how the detailed application of the methods of nonlinear dynamics and bifurcation theory is central to exploring and characterising their various dynamical features. The rich repertoire of dynamics revealed by such dynamical systems approaches arguably represents a critical step towards an understanding of the complexity of brain function.

Liley, David T. J.; Frascoli, Federico

114

Towards a New Mapping of Brain Cortex Function  

Microsoft Academic Search

The aim of imaging neuroscience is to describe the functional organization of human brain at the level of large neuronal groupings, networks and systems. The systems level of description addresses how integrated brain functions are embodied in the physical structure of the brain. Magnetic resonance imaging is currently the technique of choice for the study of cerebral structure–function relationships and

Nick S. Ward; Richard S. J. Frackowiak

2004-01-01

115

Final Report on LDRD Project 130784: Functional Brain Imaging by Tunable Multi-Spectral Event-Related Optical Signal (EROS).  

National Technical Information Service (NTIS)

Functional brain imaging is of great interest for understanding correlations between specific cognitive processes and underlying neural activity. This understanding can provide the foundation for developing enhanced human-machine interfaces, decision aide...

A. E. Speed A. Y. C. Hsu O. B. Spahn

2009-01-01

116

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

117

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.

Pigarev, Ivan N.; Pigareva, Marina L.

2014-01-01

118

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

119

Significance of epigenetics for understanding brain development, brain evolution and behaviour.  

PubMed

Two major environmental developments have occurred in mammalian evolution which have impacted on the genetic and epigenetic regulation of brain development. The first of these was viviparity and development of the placenta which placed a considerable burden of time and energy investment on the matriline, and which resulted in essential hypothalamic modifications. Maternal feeding, maternal care, parturition, milk letdown and the suspension of fertility and sexual behaviour are all determined by the maternal hypothalamus and have evolved to meet foetal needs under the influence of placental hormones. Viviparity itself provided a new environmental variable for selection pressures to operate via the co-existence over three generations of matrilineal genomes (mother, developing offspring and developing oocytes) in one individual. Also of importance for the matriline has been the evolution of epigenetic marks (imprint control regions) which are heritable and undergo reprogramming primarily in the oocyte to regulate imprinted gene expression according to parent of origin. Imprinting of autosomal genes has played a significant role in mammalian evolutionary development, particularly that of the hypothalamus and placenta. Indeed, many imprinted genes that are co-expressed in the placenta and hypothalamus play an important role in the co-adapted functioning of these organs. Thus the action and interaction of two genomes (maternal and foetal) have provided a template for transgenerational selection pressures to operate in shaping the mothering capabilities of each subsequent generation. The advanced aspects of neocortical brain evolution in primates have emancipated much of behaviour from the determining effects of hormonal action. Thus in large brain primates, most of the sexual behaviour is not reproductive hormone dependent and maternal care can and does occur outside the context of pregnancy and parturition. The neocortex has evolved to be adaptable and while the adapted changes are not inherited, the epigenetic predisposing processes can be. This provides each generation with the same ability to generate new adaptations while retaining a "cultural" predisposition to retain others. A significant evolutionary contribution to this epigenetic dimension has again been the matriline. The extensive neocortical development which takes place post-natally does so in an environment which is predominantly that of the caring guidance of the mother. Evidence for the epigenetic regulation of neocortical development is best illustrated by the GABA-ergic neurons and their long tangential migratory pathway from the ganglionic eminence, in contrast to the radial migration of principle neurons. GABA-ergic neurons play an integral role both in the developmental formation of canonical localised circuits and in synchronising widespread functional activity by the regulation of network oscillations. Such synchronisation enables distributed regions of the neocortex to coordinate firing. GABA-ergic dysfunction contributes to a broad spectrum of neurological and psychiatric disorders which can differ even across identical monozygotic twins. Moreover, major treatments for schizophrenia over the past 40 years have included the drugs lithium and valproate, both of which we now know are histone deacetylases. It is rarely the heritable dysfunctioning of these epigenetic mechanisms that is at fault, but the timing, duration and place where they are deployed. The timing and complexity in the development of the neocortex makes this region of the brain more vulnerable to perturbations. PMID:23201253

Keverne, E B

2014-04-01

120

Using ADP to Understand and Replicate Brain Intelligence: the Next Level Design  

Microsoft Academic Search

Since the 1960's the author proposed that we could understand and replicate the highest level of intelligence seen in the brain, by building ever more capable and general systems for adaptive dynamic programming (ADP) - like \\

P. J. Werbos

2007-01-01

121

Understanding actors and object-goals in the human brain  

Microsoft Academic Search

When another person takes £10 from your hand, it matters if they are a shopkeeper or a robber. That is, the meaning of a simple, goal-directed action can vary depending on the identity of the actors involved. Research examining action understanding has identified an action observation network (AON) that encodes action features such as goals and kinematics. However, it is

Richard Ramsey; Antonia F. de C. Hamilton

2010-01-01

122

Functional Interactions as Big Data in the Human Brain  

PubMed Central

Noninvasive studies of human brain function hold great potential to unlock mysteries of the human mind. The complexity of data generated by such studies, however, has prompted various simplifying assumptions during analysis. Although this has enabled considerable progress, our current understanding is partly contingent upon these assumptions. An emerging approach embraces the complexity, accounting for the fact that neural representations are widely distributed, neural processes involve interactions between regions, interactions vary by cognitive state, and the space of interactions is massive. Because what you see depends on how you look, such unbiased approaches provide the greatest flexibility for discovery.

Turk-Browne, Nicholas B.

2014-01-01

123

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—A ... fMRI) analysis of long-term effects of violent video game play on the brain has found changes in ...

124

Dietary boron, brain function, and cognitive performance.  

PubMed

Although the trace element boron has yet to be recognized as an essential nutrient for humans, recent data from animal and human studies suggest that boron may be important for mineral metabolism and membrane function. To investigate further the functional role of boron, brain electrophysiology and cognitive performance were assessed in response to dietary manipulation of boron (approximately 0.25 versus approximately 3.25 mg boron/2000 kcal/day) in three studies with healthy older men and women. Within-subject designs were used to assess functional responses in all studies. Spectral analysis of electroencephalographic data showed effects of dietary boron in two of the three studies. When the low boron intake was compared to the high intake, there was a significant (p < 0.05) increase in the proportion of low-frequency activity, and a decrease in the proportion of higher-frequency activity, an effect often observed in response to general malnutrition and heavy metal toxicity. Performance (e.g., response time) on various cognitive and psychomotor tasks also showed an effect of dietary boron. When contrasted with the high boron intake, low dietary boron resulted in significantly poorer performance (p < 0.05) on tasks emphasizing manual dexterity (studies II and III); eye-hand coordination (study II); attention (all studies); perception (study III); encoding and short-term memory (all studies); and long-term memory (study I). Collectively, the data from these three studies indicate that boron may play a role in human brain function and cognitive performance, and provide additional evidence that boron is an essential nutrient for humans. PMID:7889884

Penland, J G

1994-11-01

125

Chemotherapy altered brain functional connectivity in women with breast cancer: a pilot study.  

PubMed

Adjuvant chemotherapy is associated with improvements in long-term cancer survival. However, reports of cognitive impairment following treatment emphasize the importance of understanding the long-term effects of chemotherapy on brain functioning. Cognitive deficits found in chemotherapy patients suggest a change in brain functioning that affects specific cognitive domains such as attentional processing and executive functioning. This study examined the processes potentially underlying these changes in cognition by examining brain functional connectivity pre- and post-chemotherapy in women with breast cancer. Functional connectivity examines the temporal correlation between spatially remote brain regions in an effort to understand how brain networks support specific cognitive functions. Nine women diagnosed with breast cancer completed a functional magnetic resonance imaging (fMRI) session before chemotherapy, 1 month after, and 1 year after the completion of chemotherapy. Seed-based functional connectivity analyses were completed using seeds in the intraparietal sulcus (IPS) to examine connectivity in the dorsal anterior attention network and in the posterior cingulate cortex (PCC) to examine connectivity in the default mode network. Results showed decreased functional connectivity 1 month after chemotherapy that partially returned to baseline at 1 year in the dorsal attention network. Decreased connectivity was seen in the default mode network at 1 month and 1 year following chemotherapy. In addition, increased subjective memory complaints were noted at 1 month and 1 year post-chemotherapy. These findings suggest a detrimental effect of chemotherapy on brain functional connectivity that is potentially related to subjective cognitive assessment. PMID:23852814

Dumas, Julie A; Makarewicz, Jenna; Schaubhut, Geoffrey J; Devins, Robert; Albert, Kimberly; Dittus, Kim; Newhouse, Paul A

2013-12-01

126

Cognitive neuroscience 2.0: building a cumulative science of human brain function  

PubMed Central

Cognitive neuroscientists increasingly recognize that continued progress in understanding human brain function will require not only the acquisition of new data, but also the synthesis and integration of data across studies and laboratories. Here we review ongoing efforts to develop a more cumulative science of human brain function. We discuss the rationale for an increased focus on formal synthesis of the cognitive neuroscience literature, provide an overview of recently developed tools and platforms designed to facilitate the sharing and integration of neuroimaging data, and conclude with a discussion of several emerging developments that hold even greater promise in advancing the study of human brain function.

Yarkoni, Tal; Poldrack, Russell A.; Van Essen, David C.; Wager, Tor D.

2010-01-01

127

Brain microvascular function during cardiopulmonary bypass  

SciTech Connect

Emboli in the brain microvasculature may inhibit brain activity during cardiopulmonary bypass. Such hypothetical blockade, if confirmed, may be responsible for the reduction of cerebral metabolic rate for glucose observed in animals subjected to cardiopulmonary bypass. In previous studies of cerebral blood flow during bypass, brain microcirculation was not evaluated. In the present study in animals (pigs), reduction of the number of perfused capillaries was estimated by measurements of the capillary diffusion capacity for hydrophilic tracers of low permeability. Capillary diffusion capacity, cerebral blood flow, and cerebral metabolic rate for glucose were measured simultaneously by the integral method, different tracers being used with different circulation times. In eight animals subjected to normothermic cardiopulmonary bypass, and seven subjected to hypothermic bypass, cerebral blood flow, cerebral metabolic rate for glucose, and capillary diffusion capacity decreased significantly: cerebral blood flow from 63 to 43 ml/100 gm/min in normothermia and to 34 ml/100 gm/min in hypothermia and cerebral metabolic rate for glucose from 43.0 to 23.0 mumol/100 gm/min in normothermia and to 14.1 mumol/100 gm/min in hypothermia. The capillary diffusion capacity declined markedly from 0.15 to 0.03 ml/100 gm/min in normothermia but only to 0.08 ml/100 gm/min in hypothermia. We conclude that the decrease of cerebral metabolic rate for glucose during normothermic cardiopulmonary bypass is caused by interruption of blood flow through a part of the capillary bed, possibly by microemboli, and that cerebral blood flow is an inadequate indicator of capillary blood flow. Further studies must clarify why normal microvascular function appears to be preserved during hypothermic cardiopulmonary bypass.

Sorensen, H.R.; Husum, B.; Waaben, J.; Andersen, K.; Andersen, L.I.; Gefke, K.; Kaarsen, A.L.; Gjedde, A.

1987-11-01

128

Dynamic representations and generative models of brain function.  

PubMed

The main point made in this article is that the representational capacity and inherent function of any neuron, neuronal population or cortical area is dynamic and context-sensitive. This adaptive and contextual specialisation is mediated by functional integration or interactions among brain systems with a special emphasis on backwards or top-down connections. The critical notion is that neuronal responses, in any given cortical area, can represent different things at different times. Our argument is developed under the perspective of generative models of functional brain architectures, where higher-level systems provide a prediction of the inputs to lower-level regions. Conflict between the two is resolved by changes in the higher-level representations, driven by the resulting error in lower regions, until the mismatch is 'cancelled'. In this model the specialisation of any region is determined both by bottom-up driving inputs and by top-down predictions. Specialisation is therefore not an intrinsic property of any region but depends on both forward and backward connections with other areas. Because these other areas have access to the context in which the inputs are generated they are in a position to modulate the selectivity or specialisation of lower areas. The implications for 'classical' models (e.g., classical receptive fields in electrophysiology, classical specialisation in neuroimaging and connectionism in cognitive models) are severe and suggest these models provide incomplete accounts of real brain architectures. Generative models represent a far more plausible framework for understanding selective neurophysiological responses and how representations are constructed in the brain. PMID:11287132

Friston, K J; Price, C J

2001-02-01

129

From the connectome to brain function.  

PubMed

In this Historical Perspective, we ask what information is needed beyond connectivity diagrams to understand the function of nervous systems. Informed by invertebrate circuits whose connectivities are known, we highlight the importance of neuronal dynamics and neuromodulation, and the existence of parallel circuits. The vertebrate retina has these features in common with invertebrate circuits, suggesting that they are general across animals. Comparisons across these systems suggest approaches to study the functional organization of large circuits based on existing knowledge of small circuits. PMID:23866325

Bargmann, Cornelia I; Marder, Eve

2013-06-01

130

Assessing Functional Connectivity in the Human Brain by FMRI  

PubMed Central

Functional magnetic resonance imaging is widely used to detect and delineate regions of the brain that change their level of activation in response to specific stimuli and tasks. Simple activation maps depict only the average level of engagement of different regions within distributed systems. FMRI potentially can reveal additional information about the degree by which components of large-scale neural systems are functionally coupled together to achieve specific tasks. In order to better understand how brain regions contribute to functionally connected circuits, it is necessary to record activation maps either as a function of different conditions, at different times or in different subjects. Data obtained under different conditions may then be analyzed by a variety of techniques to infer correlations and couplings between nodes in networks. Several different multivariate statistical methods have been adapted and applied to analyze the variations within such data. An approach of particular interest that is suited to studies of connectivity within single subjects makes use of acquisitions of runs of MRI images obtained while the brain is in a so-called steady state, either at rest (i.e. without any specific stimulus or task) or in a condition of continuous activation. The interregional correlations between fluctuations of MRI signal potentially reveal functional connectivity. Recent studies have established that interregional correlations between different components of circuits in each of the visual, language, motor and working memory systems can be detected in the resting state. The correlations at baseline are changed during the performance of a continuous task. In this review the various methods available for assessing connectivity are described and evaluated.

Rogers, Baxter P.; Morgan, Victoria L.; Newton, Allen T.; Gore, John C.

2007-01-01

131

Imaging structural and functional brain networks in temporal lobe epilepsy.  

PubMed

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

132

Maturation of Widely Distributed Brain Function Subserves Cognitive Development  

Microsoft Academic Search

Cognitive and brain maturational changes continue throughout late childhood and adolescence. During this time, increasing cognitive control over behavior enhances the voluntary suppression of reflexive\\/impulsive response tendencies. Recently, with the advent of functional MRI, it has become possible to characterize changes in brain activity during cognitive development. In order to investigate the cognitive and brain maturation subserving the ability to

Beatriz Luna; Keith R. Thulborn; Douglas P. Munoz; Elisha P. Merriam; Krista E. Garver; Nancy J. Minshew; Matcheri S. Keshavan; Christopher R. Genovese; William F. Eddy; John A. Sweeney

2001-01-01

133

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

Microsoft Academic Search

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

Grit Welzel; Katharina Fleckenstein; Joerg Schaefer; Brigitte Hermann; Uta Kraus-Tiefenbacher; Sabine K. Mai; Frederik Wenz

2008-01-01

134

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

135

The physiological and biochemical bases of functional brain imaging  

PubMed Central

Functional brain imaging is based on the display of computer-derived images of changes in physiological and/or biochemical functions altered by activation or depression of local functional activities in the brain. This article reviews the physiological and biochemical mechanisms involved.

2007-01-01

136

Exploring large-scale brain networks in functional MRI  

Microsoft Academic Search

Increasing emphasis has been recently put on large-scale network processing of brain functions. To explore these networks, many approaches have been proposed in functional magnetic resonance imaging (fMRI). Their objective is to answer the following two questions: (1) what brain regions are involved in the functional process under investigation? and (2) how do these regions interact? We review some of

Guillaume Marrelec; Pierre Bellec; Habib Benali

2006-01-01

137

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

138

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.

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

139

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.

Holschneider, DP; Maarek, J-M I

2008-01-01

140

A Review of Functional Brain Imaging Correlates of Successful Cognitive Aging  

PubMed Central

Preserved cognitive performance is a key feature of successful aging. Several theoretical models (compensation, hemispheric asymmetry reduction, and posterior-anterior shift) have been proposed to explain the putative underlying relationship between brain function and performance. We aimed to review imaging studies of the association between brain functional response and cognitive performance among healthy younger and older adults in order to understand the neural correlates of successful cognitive aging. MEDLINE-indexed articles published between January 1989 and May 2008, and bibliographies of these articles and related reviews were searched. Studies that measured brain function using fMRI or PET, evaluated cognitive performance, analyzed how cognitive performance related to brain response, and studied healthy older individuals were included. Forty-seven of 276 articles met these criteria. Eighty-one percent of the studies reported some brain regions in which greater activation related to better cognitive performance among older participants. This association was not universal, however, and was seen mainly in frontal cortex brain response and seemed to be more common among older compared to younger individuals. This review supports the notion of compensatory increases in brain activity in old age resulting in better cognitive performance, as suggested by hemispheric asymmetry reduction and posterior-anterior shift models of functional brain aging. However, a simple model of bigger structure ? greater brain response ? better cognitive performance may not be accurate. Suggestions for future research are discussed.

Eyler, Lisa T.; Sherzai, Abdullah; Jeste, Dilip V.

2013-01-01

141

The brain's shared circuits of interpersonal understanding: implications for psychoanalysis and psychodynamic psychotherapy.  

PubMed

Social Neuroscience maintains that human survival depends on interpersonal relations, and that shared circuits evolved to enhance our ability to interact with and understand other people. Shared circuits operate by re-creating the Other’s experience in the same brain regions used for Self experience. The interpersonal understanding made possible by shared circuits is, for the most part, outside conscious awareness and plays a role in the transference-counter transference interaction. The brain mechanisms of shared circuits are presented and clinical vignettes illustrate the use of the concept of shared circuits in the clinical setting. PMID:20865827

Pally, Regina

2010-01-01

142

Functional brain networks develop from a "local to distributed" organization.  

PubMed

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 four separate networks defined in earlier studies. As we have previously reported, we find, across development, a trend toward 'segregation' (a general decrease in correlation strength) between regions close in anatomical space and 'integration' (an increased correlation strength) between selected regions distant in space. The generalization of these earlier trends across multiple networks suggests that this is a general developmental principle for changes in functional connectivity that would extend to large-scale graph theoretic analyses of large-scale brain networks. Communities in children are predominantly arranged by anatomical proximity, while communities in adults predominantly reflect functional relationships, as defined from adult fMRI studies. In sum, over development, the organization of multiple functional networks shifts from a local anatomical emphasis in children to a more "distributed" architecture in young adults. We argue that this "local to distributed" developmental characterization has important implications for understanding the development of neural systems underlying cognition. Further, graph metrics (e.g., clustering coefficients and average path lengths) are similar in child and adult graphs, with both showing "small-world"-like properties, while community detection by modularity optimization reveals stable communities within the graphs that are clearly different between young children and young adults. These observations suggest that early school age children and adults both have relatively efficient systems that may solve similar information processing problems in divergent ways. PMID:19412534

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

2009-05-01

143

Functional Connectivity in Mild Traumatic Brain Injury  

PubMed Central

Objectives Research suggests that the majority of mild traumatic brain injury (mTBI) patients exhibit both cognitive and emotional dysfunction within the first weeks of injury, followed by symptom resolution 3–6 months post-injury. The neuronal correlates of said dysfunction are difficult to detect with standard clinical neuroimaging, complicating differential diagnosis and early identification of patients who may not recover. The current study examined whether resting state functional magnetic resonance imaging (FMRI) provides objective markers of injury and predicts cognitive, emotional and somatic complaints in mTBI patients semi-acutely (< 3 weeks post-injury) and in late recovery (3–5 month) phases. Methods Twenty seven semi-acute mTBI patients and 26 gender, age and education matched controls were studied. Fifteen out of 27 patients returned for a follow-up visit 3–5 months post-injury. The main dependent variables were spontaneous fluctuations (temporal correlation) in the default-mode (DMN) and fronto-parietal task-related (TRN) networks as measured by FMRI. Results Significant differences in self-reported cognitive, emotional and somatic complaints were observed (all p < .05), despite normal clinical (T1 and T2) imaging and neuropsychological testing results. Mild TBI patients demonstrated decreased functional connectivity within the DMN and hyper-connectivity between the DMN and lateral prefrontal cortex. Measures of functional connectivity exhibited high levels of sensitivity and specificity for patient classification and predicted cognitive complaints in the semi-acute injury stage. However, no changes in functional connectivity were observed across a four month recovery period. Conclusions Abnormal connectivity between the DMN and frontal cortex may provide objective biomarkers of mTBI and underlie cognitive impairment.

Mayer, Andrew R.; Mannell, Maggie V.; Ling, Josef; Gasparovic, Charles; Yeo, Ronald A.

2011-01-01

144

Conditional integration as a way of measuring mediated interactions between large-scale brain networks in functional MRI  

Microsoft Academic Search

Brain regions are thought to be organized in large-scale networks, and studying interactions within and between such networks using functional magnetic resonance imaging (fMRI) could prove relevant for understanding brain's functional organization. Such interactions can be quantified by looking at their integration, a generalized measure of correlation. However, such a measure of integration cannot distinguish between mediated and direct interactions.

D. Coynel; Guillaume Marrelec; Vincent Perlbarg; Julien Doyon; Habib Benali

2010-01-01

145

Understanding the Evolution of Mammalian Brain Structures; the Need for a (New) Cerebrotype Approach  

PubMed Central

The mammalian brain varies in size by a factor of 100,000 and is composed of anatomically and functionally distinct structures. Theoretically, the manner in which brain composition can evolve is limited, ranging from highly modular (“mosaic evolution”) to coordinated changes in brain structure size (“concerted evolution”) or anything between these two extremes. There is a debate about the relative importance of these distinct evolutionary trends. It is shown here that the presence of taxa-specific allometric relationships between brain structures makes a taxa-specific approach obligatory. In some taxa, the evolution of the size of brain structures follows a unique, coordinated pattern, which, in addition to other characteristics at different anatomical levels, defines what has been called here a “taxon cerebrotype”. In other taxa, no clear pattern is found, reflecting heterogeneity of the species’ lifestyles. These results suggest that the evolution of brain size and composition depends on the complex interplay between selection pressures and constraints that have changed constantly during mammalian evolution. Therefore the variability in brain composition between species should not be considered as deviations from the normal, concerted mammalian trend, but in taxa and species-specific versions of the mammalian brain. Because it forms homogenous groups of species within this complex “space” of constraints and selection pressures, the cerebrotype approach developed here could constitute an adequate level of analysis for evo-devo studies, and by extension, for a wide range of disciplines related to brain evolution.

Willemet, Romain

2012-01-01

146

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. Hum Brain Mapp 35:4566-4582, 2014. © 2014 Wiley Periodicals, Inc. PMID:24585433

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

2014-09-01

147

Development of Large-Scale Functional Brain Networks in Children  

Microsoft Academic Search

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

Kaustubh Supekar; Mark Musen; Vinod Menon

2009-01-01

148

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

149

Infrared Imaging System for Studying Brain Function  

NASA Technical Reports Server (NTRS)

A proposed special-purpose infrared imaging system would be a compact, portable, less-expensive alternative to functional magnetic resonance imaging (fMRI) systems heretofore used to study brain function. Whereas a typical fMRI system fills a large room, and must be magnetically isolated, this system would fit into a bicycle helmet. The system would include an assembly that would be mounted inside the padding in a modified bicycle helmet or other suitable headgear. The assembly would include newly designed infrared photodetectors and data-acquisition circuits on integrated-circuit chips on low-thermal-conductivity supports in evacuated housings (see figure) arranged in multiple rows and columns that would define image coordinates. Each housing would be spring-loaded against the wearer s head. The chips would be cooled by a small Stirling Engine mounted contiguous to, but thermally isolated from, the portions of the assembly in thermal contact with the wearer s head. Flexible wires or cables for transmitting data from the aforementioned chips would be routed to an integrated, multichannel transmitter and thence through the top of the assembly to a patch antenna on the outside of the helmet. The multiple streams of data from the infrared-detector chips would be sent to a remote site, where they would be processed, by software, into a three-dimensional display of evoked potentials that would represent firing neuronal bundles and thereby indicate locations of neuronal activity associated with mental or physical activity. The 3D images will be analogous to current fMRI images. The data would also be made available, in real-time, for comparison with data in local or internationally accessible relational databases that already exist in universities and research centers. Hence, this system could be used in research on, and for the diagnosis of response from the wearer s brain to physiological, psychological, and environmental changes in real time. The images would also be stored in a relational database for comparison with corresponding responses previously observed in other subjects.

Mintz, Frederick; Mintz, Frederick; Gunapala, Sarath

2007-01-01

150

Self-similar correlation function in brain resting-state functional magnetic resonance imaging  

PubMed Central

Adaptive behaviour, cognition and emotion are the result of a bewildering variety of brain spatio-temporal activity patterns. An important problem in neuroscience is to understand the mechanism by which the human brain's 100 billion neurons and 100 trillion synapses manage to produce this large repertoire of cortical configurations in a flexible manner. In addition, it is recognized that temporal correlations across such configurations cannot be arbitrary, but they need to meet two conflicting demands: while diverse cortical areas should remain functionally segregated from each other, they must still perform as a collective, i.e. they are functionally integrated. Here, we investigate these large-scale dynamical properties by inspecting the character of the spatio-temporal correlations of brain resting-state activity. In physical systems, these correlations in space and time are captured by measuring the correlation coefficient between a signal recorded at two different points in space at two different times. We show that this two-point correlation function extracted from resting-state functional magnetic resonance imaging data exhibits self-similarity in space and time. In space, self-similarity is revealed by considering three successive spatial coarse-graining steps while in time it is revealed by the 1/f frequency behaviour of the power spectrum. The uncovered dynamical self-similarity implies that the brain is spontaneously at a continuously changing (in space and time) intermediate state between two extremes, one of excessive cortical integration and the other of complete segregation. This dynamical property may be seen as an important marker of brain well-being in both health and disease.

Expert, Paul; Lambiotte, Renaud; Chialvo, Dante R.; Christensen, Kim; Jensen, Henrik Jeldtoft; Sharp, David J.; Turkheimer, Federico

2011-01-01

151

An Impairment Index of Brain Functions in Children.  

ERIC Educational Resources Information Center

An impairment index of brain functions in children was developed to summarize the performance on the Halstead-Reitan Neurological Test Battery for older children aged 9 through 14 years. Findings suggested that it may be a valid and objective indicator of brain functions in older children, although cross-validation is necessary. (Author/CL)

Reitan, Ralph M.

1984-01-01

152

Graph Analysis of Functional Brain Networks for Cognitive Control of Action in Traumatic Brain Injury  

ERIC Educational Resources Information Center

Patients with traumatic brain injury show clear impairments in behavioural flexibility and inhibition that often persist beyond the time of injury, affecting independent living and psychosocial functioning. Functional magnetic resonance imaging studies have shown that patients with traumatic brain injury typically show increased and more broadly…

Caeyenberghs, Karen; Leemans, Alexander; Heitger, Marcus H.; Leunissen, Inge; Dhollander, Thijs; Sunaert, Stefan; Dupont, Patrick; Swinnen, Stephan P.

2012-01-01

153

NeuCube: a spiking neural network architecture for mapping, learning and understanding of spatio-temporal brain data.  

PubMed

The brain functions as a spatio-temporal information processing machine. Spatio- and spectro-temporal brain data (STBD) are the most commonly collected data for measuring brain response to external stimuli. An enormous amount of such data has been already collected, including brain structural and functional data under different conditions, molecular and genetic data, in an attempt to make a progress in medicine, health, cognitive science, engineering, education, neuro-economics, Brain-Computer Interfaces (BCI), and games. Yet, there is no unifying computational framework to deal with all these types of data in order to better understand this data and the processes that generated it. Standard machine learning techniques only partially succeeded and they were not designed in the first instance to deal with such complex data. Therefore, there is a need for a new paradigm to deal with STBD. This paper reviews some methods of spiking neural networks (SNN) and argues that SNN are suitable for the creation of a unifying computational framework for learning and understanding of various STBD, such as EEG, fMRI, genetic, DTI, MEG, and NIRS, in their integration and interaction. One of the reasons is that SNN use the same computational principle that generates STBD, namely spiking information processing. This paper introduces a new SNN architecture, called NeuCube, for the creation of concrete models to map, learn and understand STBD. A NeuCube model is based on a 3D evolving SNN that is an approximate map of structural and functional areas of interest of the brain related to the modeling STBD. Gene information is included optionally in the form of gene regulatory networks (GRN) if this is relevant to the problem and the data. A NeuCube model learns from STBD and creates connections between clusters of neurons that manifest chains (trajectories) of neuronal activity. Once learning is applied, a NeuCube model can reproduce these trajectories, even if only part of the input STBD or the stimuli data is presented, thus acting as an associative memory. The NeuCube framework can be used not only to discover functional pathways from data, but also as a predictive system of brain activities, to predict and possibly, prevent certain events. Analysis of the internal structure of a model after training can reveal important spatio-temporal relationships 'hidden' in the data. NeuCube will allow the integration in one model of various brain data, information and knowledge, related to a single subject (personalized modeling) or to a population of subjects. The use of NeuCube for classification of STBD is illustrated in a case study problem of EEG data. NeuCube models result in a better accuracy of STBD classification than standard machine learning techniques. They are robust to noise (so typical in brain data) and facilitate a better interpretation of the results and understanding of the STBD and the brain conditions under which data was collected. Future directions for the use of SNN for STBD are discussed. PMID:24508754

Kasabov, Nikola K

2014-04-01

154

Using Functional Flow Diagrams to Enhance Technical Systems Understanding.  

ERIC Educational Resources Information Center

A treatment group of 20 aviation students used training manuals that presented functional flow diagrams before schematic diagrams. Comparison of data from 10 controls on a card-sort task showed that functional flow diagrams enhanced understanding of technical systems. (SK)

Satchwell, Richard E.

1997-01-01

155

Network Analysis of Intrinsic Functional Brain Connectivity in Alzheimer's Disease  

Microsoft Academic Search

Functional brain networks detected in task-free (''resting-state'') functional magnetic resonance imaging (fMRI) have a small- world architecture that reflects a robust functional organization of the brain. Here, we examined whether this functional organization is disrupted in Alzheimer's disease (AD). Task-free fMRI data from 21 AD subjects and 18 age-matched controls were obtained. Wavelet analysis was applied to the fMRI data

Kaustubh Supekar; Vinod Menon; Daniel Rubin; Mark Musen; Michael D. Greicius

2008-01-01

156

Optimization of Functional Brain ROIs via Maximization of Consistency of Structural Connectivity Profiles  

PubMed Central

Segregation and integration are two general principles of the brain’s functional architecture. Therefore, brain network analysis is of significant importance in understanding brain function. Critical to brain network construction and analysis is the identification of reliable, reproducible, and accurate network nodes, or Regions of Interest (ROIs). Task-based fMRI has been widely considered as a reliable approach to identify functionally meaningful ROIs in the brain. However, recent studies have shown that factors such as spatial smoothing could considerably shift the locations of detected activation peaks. As a result, structural and functional connectivity patterns can be significantly altered. Here, we propose a novel framework by which to optimize ROI sizes and locations, ensuring that differences between the structural connectivity profiles among a group of subjects is minimized. This framework is based on functional ROIs derived from task-based fMRI and diffusion tensor imaging (DTI) data. Accordingly, we present a new approach to describe and measure the fiber bundle similarity quantitatively within and across subjects which will facilitate the optimization procedure. Experimental results demonstrated that this framework improved the localizations of fMRI-derived ROIs. Through our optimization procedure, structural and functional connectivities were more consistent across different individuals. Overall, the ability to accurately localize network ROIs could facilitate many applications in brain imaging that rely on the accurate identification of ROIs.

Zhu, Dajiang; Li, Kaiming; Faraco, Carlos Cesar; Deng, Fan; Zhang, Degang; Guo, Lei; Miller, L. Stephen; Liu, Tianming

2011-01-01

157

Partial correlation for functional brain interactivity investigation in functional MRI.  

PubMed

Examination of functional interactions through effective connectivity requires the determination of three distinct levels of information: (1) the regions involved in the process and forming the spatial support of the network, (2) the presence or absence of interactions between each pair of regions, and (3) the directionality of the existing interactions. While many methods exist to select regions (Step 1), very little is available to complete Step 2. The two main methods developed so far, structural equation modeling (SEM) and dynamical causal modeling (DCM), usually require precise prior information to be used, while such information is sometimes lacking. Assuming that Step 1 was successfully completed, we here propose a data-driven method to deal with Step 2 and extract functional interactions from fMRI datasets through partial correlations. Partial correlation is more closely related to effective connectivity than marginal correlation and provides a convenient graphical representation for functional interactions. As an instance of brain interactivity investigation, we consider how simple hand movements are processed by the bihemispheric cortical motor network. In the proposed framework, Bayesian analysis makes it possible to estimate and test the partial statistical dependencies between regions without any prior model on the underlying functional interactions. We demonstrate the interest of this approach on real data. PMID:16777436

Marrelec, Guillaume; Krainik, Alexandre; Duffau, Hugues; Pélégrini-Issac, Mélanie; Lehéricy, Stéphane; Doyon, Julien; Benali, Habib

2006-08-01

158

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.

Liu, Xiao; Duyn, Jeff H.

2013-01-01

159

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

160

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.

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

2013-01-01

161

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

162

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

PubMed

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

2013-11-01

163

NMDA receptor function, memory, and brain aging  

PubMed Central

An increasing level of N-methyl-D-aspartate (NMDA) receptor hypofunction within the brain is associated with memory and learning impairments, with psychosis, and ultimately with excitotoxic brain injury. As the brain ages, the NMDA receptor system becomes progressively hypofunctional, contributing to decreases in memory and learning performance. In those individuals destined to develop Alzheimer's disease, other abnormalities (eg, amyloidopathy and oxidative stress) interact to increase the NMDA receptor hypofunction (NRHypo) burden. In these vulnerable individuals, the brain then enters into a severe and persistent NRHypo state, which can lead to widespread neurodegeneration with accompanying mental symptoms and further cognitive deterioration. If the hypotheses described herein prove correct, treatment implications may be considerable. Pharmacological methods for preventing the overstimulation of vulnerable corticolimbic pyramidal neurons developed in an animal model may be applicable to the prevention and treatment of Alzheimer's disease.

Newcomer, John W.; Farber, Nuri B.; Olney, John W.

2000-01-01

164

Cultural neuroscience of the self: understanding the social grounding of the brain  

PubMed Central

Cultural neuroscience is an interdisciplinary field of research that investigates interrelations among culture, mind and the brain. Drawing on both the growing body of scientific evidence on cultural variation in psychological processes and the recent development of social and cognitive neuroscience, this emerging field of research aspires to understand how culture as an amalgam of values, meanings, conventions, and artifacts that constitute daily social realities might interact with the mind and its underlying brain pathways of each individual member of the culture. In this article, following a brief review of studies that demonstrate the surprising degree to which brain processes are malleably shaped by cultural tools and practices, the authors discuss cultural variation in brain processes involved in self-representations, cognition, emotion and motivation. They then propose (i) that primary values of culture such as independence and interdependence are reflected in the compositions of cultural tasks (i.e. daily routines designed to accomplish the cultural values) and further (ii) that active and sustained engagement in these tasks yields culturally patterned neural activities of the brain, thereby laying the ground for the embodied construction of the self and identity. Implications for research on culture and the brain are discussed.

Park, Jiyoung

2010-01-01

165

From The Cover: Microtransplantation of functional receptors and channels from the Alzheimer's brain to frog oocytes  

NASA Astrophysics Data System (ADS)

About a decade ago, cell membranes from the electric organ of Torpedo and from the rat brain were transplanted to frog oocytes, which thus acquired functional Torpedo and rat neurotransmitter receptors. Nevertheless, the great potential that this method has for studying human diseases has remained virtually untapped. Here, we show that cell membranes from the postmortem brains of humans that suffered Alzheimer's disease can be microtransplanted to the plasma membrane of Xenopus oocytes. We show also that these postmortem membranes carry neurotransmitter receptors and voltage-operated channels that are still functional, even after they have been kept frozen for many years. This method provides a new and powerful approach to study directly the functional characteristics and structure of receptors, channels, and other membrane proteins of the Alzheimer's brain. This knowledge may help in understanding the basis of Alzheimer's disease and also help in developing new treatments. -aminobutyric acid receptors | sodium channels | calcium channels | postmortem brain

Miledi, R.; Dueñas, Z.; Martinez-Torres, A.; Kawas, C. H.; Eusebi, F.

2004-02-01

166

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

167

Inhibition and brain work.  

PubMed

The major part of the brain's energy budget ( approximately 60%-80%) is devoted to its communication activities. While inhibition is critical to brain function, relatively little attention has been paid to its metabolic costs. Understanding how inhibitory interneurons contribute to brain energy consumption (brain work) is not only of interest in understanding a fundamental aspect of brain function but also in understanding functional brain imaging techniques which rely on measurements related to blood flow and metabolism. Herein we examine issues relevant to an assessment of the work performed by inhibitory interneurons in the service of brain function. PMID:18054855

Buzsáki, György; Kaila, Kai; Raichle, Marcus

2007-12-01

168

Information Mining in Brain Data  

Microsoft Academic Search

Brain functional connectivity, effective connectivity, and coordination among brain regions have become the hot problems in the studies of human brain functions and diseases. With more brain data accumulated, researchers in different fields are so eager to understand more profoundly how the brain systems work. For various brain data, scientists of information science have to face two basic problems: how

Yao Li

2005-01-01

169

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

170

Imaging emotional brain functions: Conceptual and methodological issues  

Microsoft Academic Search

This article reviews the psychophysiological and brain imaging literature on emotional brain function from a methodological point of view. The difficulties in defining, operationalising and measuring emotional activation and, in particular, aversive learning will be considered. Emotion is a response of the organism during an episode of major significance and involves physiological activation, motivational, perceptual, evaluative and learning processes, motor

Martin Peper

2006-01-01

171

Specific monitoring of neonatal brain function with optimized frequency bands  

Microsoft Academic Search

Early detection of altered brain function can be helpful in preventing the development of serious brain damage. Power spectral analysis of continuous EEG is an established tool in corresponding clinical monitoring. The commonly used EEG power classifiers are based on the power within particular frequency bands. It can be supposed that individually adapted frequency bands allow a more specific monitoring

Dirk Hoyer; Reinhard Bauer; Kirsten Conrad; Mirek Galicki; Axel Döring; Heike Hoyer; Bernd Walter; H. Witie; Ulrich Zwiener

2001-01-01

172

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

173

The Efficiency of a Small-World Functional Brain Network  

NASA Astrophysics Data System (ADS)

We investigate whether the small-world topology of a functional brain network means high information processing efficiency by calculating the correlation between the small-world measures of a functional brain network and behavioral reaction during an imagery task. Functional brain networks are constructed by multichannel event-related potential data, in which the electrodes are the nodes and the functional connectivities between them are the edges. The results show that the correlation between small-world measures and reaction time is task-specific, such that in global imagery, there is a positive correlation between the clustering coefficient and reaction time, while in local imagery the average path length is positively correlated with the reaction time. This suggests that the efficiency of a functional brain network is task-dependent.

Zhao, Qing-Bai; Zhang, Xiao-Fei; Sui, Dan-Ni; Zhou, Zhi-Jin; Chen, Qi-Cai; Tang, Yi-Yuan

2012-04-01

174

Brain function in social anxiety disorder.  

PubMed

What have these studies revealed about SAD? First, few studies have been performed so far, with even fewer replications. Most of the work has been exploratory in nature and follows the paradigms used in PD. This approach has been justifiably criticized. The use of psychological (naturalistic) challenges may be more appropriate in SP than chemical challenges. The paradigms of public speaking, autobiographical scripts, or similar behavioral challenges merit further use, exploration, and validation if symptoms resembling those of the condition proper are to be induced in experimental circumstances. However, some tentative conclusions can be drawn from the research performed so far. There is no enough evidence to support the presence of structural brain abnormality in SAD. Admittedly, such a finding would have been very unlikely. On the other hand, evidence of subtle functional abnormalities is accumulating. On the nosologic question, there appear to be differences from PD. While in some challenges (e.g., CO2 and pentagastrin) the two conditions differ only in degree, in others (e.g., lactate, caffeine, and flumazenil), the separation is clearer. Equally, there is a strong argument to differentiate the generalized from the specific form of social anxiety on the basis of substantial (albeit accidental) findings outlined earlier. More sophisticated neuroimaging techniques, directly comparing patients from both groups before and after pharmacologic or psychological treatment, should provide more conclusive evidence on this issue. What might also help future research is the integration of biological investigations with specific personality profiles. In one study, SAD patients scored low in novelty seeking, self-directedness and cooperativeness and high in harm avoidance. It has been hypothesized that such results indicate serotonergic and dopaminergic dysregulation, which is consistent with the findings described earlier. The best evidence for neurotransmitter abnormality so far is for altered dopamine function at the level of the basal ganglia, either pre- or postsynaptic, which may result in reduced basal ganglia function so that the normal fluidity of social motor functions (e.g., smiling, eye movements, and speech) are impaired, thus leading to the cognitive symptoms of social anxiety and the subsequent generation of avoidance behavior. Such patients should respond poorly to antipsychotics, and additional challenges with these drugs could be used to test this theory. Furthermore, more research needs to be done to elucidate the mechanism by which SSRIs work in SAD. Neuroanatomical models of social anxiety (Fig. 4) [see structure: Text], explaining the site of action of drugs and psychological treatments, have been proposed in recent years. Central to these models is the notion of an innate anxiety circuit, which could be tentatively identified with the behavioral inhibition system, the septohippocampal system. This area receives 5-HT, NE, and dopamine input and has connections with the cortex and limbic structures. The relevance of these models remains to be assessed in experiments that are specifically designed to test them. PMID:11723629

Argyropoulos, S V; Bell, C J; Nutt, D J

2001-12-01

175

The contribution of novel brain imaging techniques to understanding the neurobiology of mental retardation and developmental disabilities.  

PubMed

Studying the biological mechanisms underlying mental retardation and developmental disabilities (MR/DD) is a very complex task. This is due to the wide heterogeneity of etiologies and pathways that lead to MR/DD. Breakthroughs in genetics and molecular biology and the development of sophisticated brain imaging techniques during the last decades have facilitated the emergence of a field called Behavioral Neurogenetics. Behavioral Neurogenetics focuses on studying genetic diseases with known etiologies that are manifested by unique cognitive and behavioral phenotypes. In this review, we describe the principles of magnetic resonance imaging (MRI) techniques, including structural MRI, functional MRI, and diffusion tensor imaging (DTI), and how they are implemented in the study of Williams (WS), velocardiofacial (VCFS), and fragile X (FXS) syndromes. From WS we learn that dorsal stream abnormalities can be associated with visuospatial deficits; VCFS is a model for exploring the molecular and brain pathways that lead to psychiatric disorders for which subjects with MR/DD are at increased risk; and finally, findings from multimodal imaging techniques show that aberrant frontal-striatal connections are implicated in the executive function and attentional deficits of subjects with FXS. By deciphering the molecular pathways and brain structure and function associated with cognitive deficits, we will gain a better understanding of the pathophysiology of MR/DD, which will eventually make possible more specific treatments for this population. PMID:16240408

Gothelf, Doron; Furfaro, Joyce A; Penniman, Lauren C; Glover, Gary H; Reiss, Allan L

2005-01-01

176

Mapping Functional Brain Development: Building a Social Brain Through Interactive Specialization  

Microsoft Academic Search

The authors review a viewpoint on human functional brain development, interactive specialization (IS), and its application to the emerging network of cortical regions referred to as the social brain. They advance the IS view in 2 new ways. First, they extend IS into a domain to which it has not previously been applied—the emergence of social cognition and mentalizing computations

Mark H. Johnson; Tobias Grossmann; Kathrin Cohen Kadosh

2009-01-01

177

Correlation between cognitive brain function and electrical brain activity in dementia of Alzheimer type  

Microsoft Academic Search

Summary Psychometric tests which assess cognitive brain function in dementia disorders are partly prone to artifacts, e.g., the experience of the investigator and the cooperation of the patient influences the results. An objective way to assess the degree of cognitive disturbance could be to measure neuronal activity represented by the electrical brain activity. The aim of the present study was

T. Dierks; L. Frölich; R. Ihl; K. Maurer

1995-01-01

178

Developmental trajectories during adolescence in males and females: a cross-species understanding of underlying brain changes  

PubMed Central

Adolescence is a transitional period between childhood and adulthood that encompasses vast changes within brain systems that parallel some, but not all, behavioral changes. Elevations in emotional reactivity and reward processing follow an inverted U shape in terms of onset and remission, with the peak occurring during adolescence. However, cognitive processing follows a more linear course of development. This review will focus on changes within key structures and will highlight the relationships between brain changes and behavior, with evidence spanning from functional magnetic resonance imaging (fMRI) in humans to molecular studies of receptor and signaling factors in animals. Adolescent changes in neuronal substrates will be used to understand how typical and atypical behaviors arise during adolescence. We draw upon clinical and preclinical studies to provide a neural framework for defining adolescence and its role in the transition to adulthood.

Brenhouse, Heather C.; Andersen, Susan L.

2011-01-01

179

Understanding the Structure and Function of the Immunological Synapse  

PubMed Central

The immunological synapse has been an area of very active scientific interest over the last decade. Surprisingly, much about the synapse remains unknown or is controversial.  Here we review some of these current issues in the field:  how the synapse is defined, its potential role in T-cell function, and our current understanding about how the synapse is formed.

Dustin, Michael L.; Chakraborty, Arup K.; Shaw, Andrey S.

2010-01-01

180

Understanding the Role of Nutrition in the Brain & Behavioral Development of Toddlers and Preschool Children: Identifying and Overcoming Methodological Barriers  

PubMed Central

The pre-school years (i.e., 1–5 years of age) is a time of rapid and dramatic postnatal brain development, i.e., neural plasticity, and of fundamental acquisition of cognitive development i.e., working memory, attention and inhibitory control. Also, it is a time of transition from a direct maternal mediation/selection of diet-based nutrition to food selection that is more based on self-selection and self-gratification. However, there have been fewer published studies in pre-school children than in infants or school-aged children that examined the role of nutrition in brain/mental development (i.e., 125 studies vs. 232 and 303 studies, respectively during the last 28 years, Figure 1). This may arise because of age-related variability, in terms of individual differences in temperament, linguistic ability, and patterns of neural activity that may affect assessment of neural and cognitive development in pre-school children. In this review, we suggest several approaches for assessing brain function in children that can be refined. It would be desirable if the discipline developed some common elements to be included in future studies of diet and brain function, with the idea that they would complement more targeted measures based on time of exposure and understanding of data from animal models. Underlining this approach is the concepts of “window of sensitivity” during which nutrients may affect postnatal neural development: investigators and expert panels need to specifically look for region-specific changes and do so with understanding of the likely time window during which the nutrient was, or was not available. (244 words)

Rosales, Francisco J.; Reznick, J. Steven; Zeisel, Steven H.

2009-01-01

181

Network Analysis of Intrinsic Functional Brain Connectivity in Alzheimer's Disease  

PubMed Central

Functional brain networks detected in task-free (“resting-state”) functional magnetic resonance imaging (fMRI) have a small-world architecture that reflects a robust functional organization of the brain. Here, we examined whether this functional organization is disrupted in Alzheimer's disease (AD). Task-free fMRI data from 21 AD subjects and 18 age-matched controls were obtained. Wavelet analysis was applied to the fMRI data to compute frequency-dependent correlation matrices. Correlation matrices were thresholded to create 90-node undirected-graphs of functional brain networks. Small-world metrics (characteristic path length and clustering coefficient) were computed using graph analytical methods. In the low frequency interval 0.01 to 0.05 Hz, functional brain networks in controls showed small-world organization of brain activity, characterized by a high clustering coefficient and a low characteristic path length. In contrast, functional brain networks in AD showed loss of small-world properties, characterized by a significantly lower clustering coefficient (p<0.01), indicative of disrupted local connectivity. Clustering coefficients for the left and right hippocampus were significantly lower (p<0.01) in the AD group compared to the control group. Furthermore, the clustering coefficient distinguished AD participants from the controls with a sensitivity of 72% and specificity of 78%. Our study provides new evidence that there is disrupted organization of functional brain networks in AD. Small-world metrics can characterize the functional organization of the brain in AD, and our findings further suggest that these network measures may be useful as an imaging-based biomarker to distinguish AD from healthy aging.

Supekar, Kaustubh; Menon, Vinod; Rubin, Daniel; Musen, Mark; Greicius, Michael D.

2008-01-01

182

[Physiological function of blood-brain barrier transporters as the CNS supporting and protecting system].  

PubMed

The blood-brain barrier (BBB) segregates the circulating blood from interstitial fluid in the brain and restricts drug permeability into the brain. Our latest studies have revealed that the BBB transporters play important physiological roles in maintaining the brain environment. For an energy-storing system, the creatine transporter localized at the brain capillary endothelial cells (BCECs) mediates the supply of creatine from the blood to the brain. The BBB is involved in the brain-to-blood efflux transport of gamma-aminobutyric acid, and GAT2/BGT-1 mediates this transport process. BCECs also express serotonin and norepinephrine transporters. Organic anion transporter 3 (OAT3) and ASCT2 are localized at the abluminal membrane of the BCECs. OAT3 is involved in the brain-to-blood efflux of a dopamine metabolite, a uremic toxin, and thiopurine nucleobase analogues. ASCT2 plays a role in L-isomer-selective aspartic acid efflux transport at the BBB. Dehydroepiandrosterone sulfate and small neutral amino acids undergo brain-to-blood efflux transport mediated by organic anion transporting polypeptide 2 and ATA2, respectively. The BBB transporters are regulated by various factors: ATA2 by osmolarity, taurine transporter by tumor necrosis factor-alpha, and L-cystine/L-glutamic acid exchange transporter by oxidative stress. Clarifying the physiological roles of BBB transport systems should give important information allowing the development of better central nervous system (CNS) drugs and improving our understanding of the relationship between CNS disorders and BBB function. PMID:15516806

Ohtsuki, Sumio

2004-11-01

183

Understanding well-being in the evolutionary context of brain development.  

PubMed Central

Much of the work on well-being and positive emotions has tended to focus on the adult, partly because this is when problems are manifest and well-being often becomes an issue by its absence. However, it is pertinent to ask if early life events might engender certain predispositions that have consequences for adult well-being. The human brain undergoes much of its growth and development postnatally until the age of seven and continues to extend its synaptic connections well into the second decade. Indeed, the prefrontal association cortex, areas of the brain concerned with forward planning and regulatory control of emotional behaviour, continue to develop until the age of 20. In this article, I consider the significance of this extended postnatal developmental period for brain maturation and how brain evolution has encompassed certain biological changes and predispositions that, with our modern lifestyle, represent risk factors for well-being. An awareness of these sensitive phases in brain development is important in understanding how we might facilitate secure relationships and high self-esteem in our children. This will provide the firm foundations on which to develop meaningful lifestyles and relationships that are crucial to well-being.

Keverne, Eric B

2004-01-01

184

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.

Pereira, Francisco; Detre, Greg; Botvinick, Matthew

2011-01-01

185

Graph Theoretical Analysis of Sedation's Effect on Whole Brain Functional System in School-Aged Children  

PubMed Central

Abstract The neurophysiological mechanism underlying sedation, especially in school-aged children, remains largely unknown. The recently emerged resting-state functional magnetic resonance imaging (rsfMRI) technique, capable of delineating brain's functional interaction pattern among distributed brain areas, proves to be a unique and powerful tool to study sedation-induced brain reorganization. Based on a relatively large school-aged children population (n=28, 10.3±2.6 years, range 7–15 years) and leveraging rsfMRI and graph theoretical analysis, this study aims to delineate sedation-induced changes in brain's information transferring property from a whole brain system perspective. Our results show a global deterioration in brain's efficiency properties (p=0.0085 and 0.0018, for global and local efficiency, respectively) with a locally graded distribution featuring significant disruptions of key consciousness-related regions. Moreover, our results also indicate a redistribution of brain's information-processing hubs characterized by a right and posterior shift as consistent with the reduced level of consciousness during sedation. Overall, our findings inform a sedation-induced functional reorganization pattern in school-aged children that greatly improve our understanding of sedation's effect in children and may potentially serve as reference for future sedation-related experimental studies and clinical applications.

Wei, Zhen; Alcauter, Sarael; Jin, Ke; Peng, Zi-wen

2013-01-01

186

Trypsin and trypsin-like proteases in the brain: proteolysis and cellular functions.  

PubMed

Several serine proteases including thrombin, tissue-type plasminogen activator and urokinase-type plasminogen activator have been well characterized in the brain. In this article, we review the brain-related trypsin and trypsin-like serine proteases. Accumulating evidence demonstrates that trypsin and trypsin-like serine proteases play very important roles in neural development, plasticity, neurodegeneration and neuroregeneration in the brain. Neuropsin is able to hydrolyze the extracellular matrix components by its active site serine, and regulates learning and memory in normal brain. The mutant neurotrypsin contributes to mental retardation in children. Neurosin seems to be involved in the pathogenesis of neurodegenerative disorders, like Alzheimer's disease, Parkinson's disease or multiple sclerosis. Although mesotrypsin/trypsin IV is also implicated in neurodegeneration, its functional significance still remains largely unknown. Particularly, mesotrypsin/trypsin IV, P22 and neurosin exert their physiological and pathological functions through activation of certain protease-activated receptors (PARs). In the brain, the presence of serpins controls the activity of serine proteases. Therefore, understanding the interaction among brain trypsin, serpins and PARs will provide invaluable tools for regulating normal brain functions and for the clinical treatment of neural disorders. PMID:17965832

Wang, Y; Luo, W; Reiser, G

2008-01-01

187

Cognitive fitness of cost-efficient brain functional networks  

PubMed Central

The human brain's capacity for cognitive function is thought to depend on coordinated activity in sparsely connected, complex networks organized over many scales of space and time. Recent work has demonstrated that human brain networks constructed from neuroimaging data have economical small-world properties that confer high efficiency of information processing at relatively low connection cost. However, it has been unclear how the architecture of complex brain networks functioning at different frequencies can be related to behavioral performance on cognitive tasks. Here, we show that impaired accuracy of working memory could be related to suboptimal cost efficiency of brain functional networks operating in the classical ? frequency band, 15–30 Hz. We analyzed brain functional networks derived from magnetoencephalography data recorded during working-memory task performance in 29 healthy volunteers and 28 people with schizophrenia. Networks functioning at higher frequencies had greater global cost efficiency than low-frequency networks in both groups. Superior task performance was positively correlated with global cost efficiency of the ?-band network and specifically with cost efficiency of nodes in left lateral parietal and frontal areas. These results are consistent with biophysical models highlighting the importance of ?-band oscillations for long-distance functional connections in brain networks and with pathophysiological models of schizophrenia as a dysconnection syndrome. More generally, they echo the saying that “less is more”: The information processing performance of a network can be enhanced by a sparse or low-cost configuration with disproportionately high efficiency.

Bassett, Danielle S.; Bullmore, Edward T.; Meyer-Lindenberg, Andreas; Apud, Jose A.; Weinberger, Daniel R.; Coppola, Richard

2009-01-01

188

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.

Poldrack, Russell A.

2014-01-01

189

Understanding the Folding-Function Tradeoff in Proteins  

PubMed Central

When an amino-acid sequence cannot be optimized for both folding and function, folding can get compromised in favor of function. To understand this tradeoff better, we devise a novel method for extracting the “function-less” folding-motif of a protein fold from a set of structurally similar but functionally diverse proteins. We then obtain the ?-trefoil folding-motif, and study its folding using structure-based models and molecular dynamics simulations. CompariA protein sequence serves two purpson with the folding of wild-type ?-trefoil proteins shows that function affects folding in two ways: In the slower folding interleukin-1?, binding sites make the fold more complex, increase contact order and slow folding. In the faster folding hisactophilin, residues which could have been part of the folding-motif are used for function. This reduces the density of native contacts in functional regions and increases folding rate. The folding-motif helps identify subtle structural deviations which perturb folding. These may then be used for functional annotation. Further, the folding-motif could potentially be used as a first step in the sequence design of function-less scaffold proteins. Desired function can then be engineered into these scaffolds.

Gosavi, Shachi

2013-01-01

190

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

191

Functional Connectivity MR Imaging Reveals Cortical Functional Connectivity in the Developing Brain  

Microsoft Academic Search

BACKGROUND AND PURPOSE: Unlike conventional functional MR imaging where external sensory\\/ cognitive paradigms are needed to specifically activate different regions of the brain, resting functional connectivity MR imaging acquires images in the absence of cognitive demands (a resting condition) and detects brain regions, which are highly temporally correlated. Therefore, resting functional MR imaging is highly suited for the study of

W. Lin; Q. Zhu; W. Gao; Y. Chen; C.-H. Toh; M. Styner; G. Gerig; J. K. Smith; B. Biswal; J. H. Gilmore

2008-01-01

192

Functional Geometry Alignment and Localization of Brain Areas  

PubMed Central

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 as brain tumors, which can cause substantial reorganization of functional systems. In such cases spatial registration based on anatomical data is only of limited value if the goal is to establish correspondences of functional areas among different individuals, or to localize potentially displaced active regions. Rather than rely on spatial alignment, we propose to perform registration in an alternative space whose geometry is governed by the functional interaction patterns in the brain. We first embed each brain into a functional map that reflects connectivity patterns during a fMRI experiment. The resulting functional maps are then registered, and the obtained correspondences are propagated back to the two brains. In application to a language fMRI experiment, our preliminary results suggest that the proposed method yields improved functional correspondences across subjects. This advantage is pronounced for subjects with tumors that affect the language areas and thus cause spatial reorganization of the functional regions.

Langs, Georg; Golland, Polina; Tie, Yanmei; Rigolo, Laura; Golby, Alexandra J.

2011-01-01

193

Mapping brain circuit function in vivo using two-photon fluorescence microscopy.  

PubMed

Mapping the activity of neuronal circuits with high resolution in the intact brain is a fundamental step toward understanding brain function. In the last several years, nonlinear microscopy combined with fluorescent activity reporters has become a crucial tool for achieving this goal. In this review article, we will highlight the principles underlying nonlinear microscopy and discuss its application to neuroscience, focusing on recent functional studies in the rodent neocortex in combination with genetically encoded calcium indicators. Microsc. Res. Tech. 77:492-501, 2014. © 2014 Wiley Periodicals, Inc. PMID:24504776

Bovetti, Serena; Moretti, Claudio; Fellin, Tommaso

2014-07-01

194

Magnetic Resonance Imaging Mapping of Brain Function Human Visual Cortex  

PubMed Central

Belliveau JW, Kwong KK, Kennedy DN, Baker JR, Stern CE, Benson R, Chesler DA, Weisskoff RM, Cohen MS, Tootell RBH, Fox PT, Brady TJ, Rosen BR. Magnetic resonance imaging mapping of brain function: human visual cortex. Invest Radiol 1992;27:SS9–S65. Magnetic resonance imaging (MRI) studies of human brain activity are described. Task-induced changes in brain cognitive state were measured using high-speed MRI techniques sensitive to changes in cerebral blood volume (CBV), blood flow (CBF), and blood oxygenation. These techniques were used to generate the first functional MRI maps of human task activation, by using a visual stimulus paradigm. The methodology of MRI brain mapping and results from the investigation of the functional organization and frequency response of human primary visual cortex (Vl) are presented.

BELLIVEAU, J.W.; KWONG, K.K.; KENNEDY, D.N.; BAKER, J.R.; STERN, C.E.; BENSON, R.; CHESLER, D.A.; WEISSKOFF, R.M.; COHEN, M.S.; TOOTELL, R.B.H.; FOX, P.T.; BRADY, T.J.; ROSEN, B.R.

2014-01-01

195

Brain function decoding process and system  

US Patent & Trademark Office Database

A method of interpreting cognitive response to a stimulus is disclosed. The method includes collecting baseline neural activity data from a subject absent a stimulus. Neural activity data is collected while the subject is being stimulated through exposure to a stimulus. A unique three-dimensional cognitive engram is then plotted representative of cerebral regions of stimulated neural activity caused by the stimulus. A novel graphical representation is plotted in three dimensions to indicate the brain region response unique to that stimulus.

2009-12-01

196

Hormones, Brain Plasticity and Reproductive Functions  

Microsoft Academic Search

The magnocellular oxytocin system of the hypothalamus illustrates remarkably well activity-dependent structural plasticity\\u000a in the adult brain. Its neurons secrete the neurohormone oxytocin, which plays a key role in the initiation of parturition\\u000a and maintenance of lactation. The somata and dendrites of oxytocin neurons accumulate in the supraoptic and paraventricular\\u000a nuclei of the hypothalamus whereas their axons project to the

Dionysia T. Theodosis

197

The impact of alcohol dependence on social brain function.  

PubMed

The impact of alcoholism (ALC) or alcohol dependence on the neural mechanisms underlying cognitive and affective empathy (i.e. the different routes to understanding other people's minds) in schizophrenic patients and non-schizophrenic subjects is still poorly understood. We therefore aimed at determining the extent to which the ability to infer other people's mental states and underlying neural mechanisms were affected by ALC. We examined 48 men, who suffered either from ALC, schizophrenia, both disorders or none of these disorders, using functional magnetic resonance imaging while performing on a mind reading task that involves both cognitive and affective aspects of empathy. Using voxel-based morphometry, we additionally examined whether between-group differences in functional activity were associated with deficits in brain structural integrity. During mental state attribution, all clinical groups as compared with healthy controls exhibited poor performance as well as reduced right-hemispheric insular function with the highest error rate and insular dysfunction seen in the schizophrenic patients without ALC. Accordingly, both behavioral performance and insular functioning revealed schizophrenia × ALC interaction effects. In addition, schizophrenic patients relative to non-schizophrenic subjects (regardless of ALC) exhibited deficits in structural integrity and task-related recruitment of the left ventrolateral prefrontal cortex (vlPFC). Our data suggest that ALC-related impairment in the ability to infer other people's mental states is limited to insular dysfunction and thus deficits in affective empathy. By contrast, mentalizing in schizophrenia (regardless of ALC) may be associated with insular dysfunction as well as a combination of structural and functional deficits in the left vlPFC. PMID:22340281

Gizewski, Elke R; Müller, Bernhard W; Scherbaum, Norbert; Lieb, Bodo; Forsting, Michael; Wiltfang, Jens; Leygraf, Norbert; Schiffer, Boris

2013-01-01

198

Obesity Increases Cerebrocortical Reactive Oxygen Species And Impairs Brain Function  

PubMed Central

Nearly two-thirds of the population in the United States is overweight or obese, and this unprecedented level of obesity will undoubtedly have a profound impact on overall health, although little is currently known about the effects of obesity on the brain. The objective of the current study was to investigate cerebral oxidative stress and cognitive decline in the context of diet-induced obesity (DIO). We demonstrate for the first time that DIO induces higher levels of reactive oxygen species (ROS) in the brain, and promotes cognitive impairment. Importantly, we also demonstrate for the first time in these studies that both body weight and adiposity are tightly correlated with the level of ROS. Interestingly, ROS were not correlated with cognitive decline in this model. Alterations in the antioxidant/detoxification Nrf2 pathway, superoxide dismutase, and catalase were not significantly altered in response to DIO. A significant impairment in glutathione peroxidase was observed in response to DIO. Taken together, these data demonstrate for the first time that DIO increases the level of total and individual ROS in the brain, and highlight a direct relationship between the amount of adiposity and the level of oxidative stress within the brain. These data have important implications for understanding the negative effects of obesity on the brain, and are vital to understanding the role of oxidative stress in mediating the effects of obesity on the brain.

Freeman, Linnea R.; Zhang, Le; Nair, Anand; Dasuri, Kalavathi; Francis, Joseph; Fernandez-Kim, Sun-Ok; Bruce-Keller, Annadora J.; Keller, Jeffrey N.

2014-01-01

199

Influence of estradiol on functional brain organization for working memory  

PubMed Central

Working memory is a cognitive function that is affected by aging and disease. To better understand the neural substrates for working memory, the present study examined the influence of estradiol on working memory using functional magnetic resonance imaging. Pre-menopausal women were tested on a verbal n-back task during the early (EF) and late follicular (LF) phases of the menstrual cycle. Although brain activation patterns were similar across the two phases, the most striking pattern that emerged was that estradiol had different associations with the two hemispheres. Increased activation in left frontal circuitry in the LF phase was associated with increased estradiol levels and decrements in working memory performance. In contrast, increased activation in right hemisphere regions in the LF phase was associated with improved task performance. The present study showed that better performance in the LF than the EF phase was associated with a pattern of reduced recruitment of the left-hemisphere and increased recruitment of the right-hemisphere in the LF compared to EF phase. We speculate that estradiol interferes with left-hemisphere working-memory processing in the LF phase, but that recruitment of the right hemisphere can compensate for left-hemisphere interference. This may be related to the proposal that estradiol can reduce cerebral asymmetries by modulating transcallosal communication (Hausmann, 2005).

Joseph, Jane E.; Swearingen, Joshua; Corbly, Christine R.; Curry, Thomas E.; Kelly, Thomas H.

2011-01-01

200

ABCD: a functional database for the avian brain.  

PubMed

Here we present the first database developed for storing, retrieving and cross-referencing neuroscience information about the connectivity of the avian brain. The Avian Brain Circuitry Database (ABCD) contains entries about the new and old terminology of the areas and their hierarchy, data on connections between brain regions, as well as a functional keyword system linked to brain regions and connections. Data were collected from the primary literature and textbooks, and an online submission system was developed to facilitate further data collection directly from researchers. The database aims to help spread the results of avian connectivity studies, the recently revised nomenclature and also to provide data for brain network research. ABCD is freely available at http://www.behav.org/abcd. PMID:17889371

Schrott, Aniko; Kabai, Peter

2008-01-30

201

Tai Chi Chuan optimizes the functional organization of the intrinsic human brain architecture in older adults  

PubMed Central

Whether Tai Chi Chuan (TCC) can influence the intrinsic functional architecture of the human brain remains unclear. To examine TCC-associated changes in functional connectomes, resting-state functional magnetic resonance images were acquired from 40 older individuals including 22 experienced TCC practitioners (experts) and 18 demographically matched TCC-naïve healthy controls, and their local functional homogeneities across the cortical mantle were compared. Compared to the controls, the TCC experts had significantly greater and more experience-dependent functional homogeneity in the right post-central gyrus (PosCG) and less functional homogeneity in the left anterior cingulate cortex (ACC) and the right dorsal lateral prefrontal cortex. Increased functional homogeneity in the PosCG was correlated with TCC experience. Intriguingly, decreases in functional homogeneity (improved functional specialization) in the left ACC and increases in functional homogeneity (improved functional integration) in the right PosCG both predicted performance gains on attention network behavior tests. These findings provide evidence for the functional plasticity of the brain’s intrinsic architecture toward optimizing locally functional organization, with great implications for understanding the effects of TCC on cognition, behavior and health in aging population.

Wei, Gao-Xia; Dong, Hao-Ming; Yang, Zhi; Luo, Jing; Zuo, Xi-Nian

2014-01-01

202

Insulin in the brain: sources, localization and functions.  

PubMed

Historically, insulin is best known for its role in peripheral glucose homeostasis, and insulin signaling in the brain has received less attention. Insulin-independent brain glucose uptake has been the main reason for considering the brain as an insulin-insensitive organ. However, recent findings showing a high concentration of insulin in brain extracts, and expression of insulin receptors (IRs) in central nervous system tissues have gathered considerable attention over the sources, localization, and functions of insulin in the brain. This review summarizes the current status of knowledge of the peripheral and central sources of insulin in the brain, site-specific expression of IRs, and also neurophysiological functions of insulin including the regulation of food intake, weight control, reproduction, and cognition and memory formation. This review also considers the neuromodulatory and neurotrophic effects of insulin, resulting in proliferation, differentiation, and neurite outgrowth, introducing insulin as an attractive tool for neuroprotection against apoptosis, oxidative stress, beta amyloid toxicity, and brain ischemia. PMID:22956272

Ghasemi, Rasoul; Haeri, Ali; Dargahi, Leila; Mohamed, Zahurin; Ahmadiani, Abolhassan

2013-02-01

203

Pattern Classification of Large-Scale Functional Brain Networks: Identification of Informative Neuroimaging Markers for Epilepsy  

PubMed Central

The accurate prediction of general neuropsychiatric disorders, on an individual basis, using resting-state functional magnetic resonance imaging (fMRI) is a challenging task of great clinical significance. Despite the progress to chart the differences between the healthy controls and patients at the group level, the pattern classification of functional brain networks across individuals is still less developed. In this paper we identify two novel neuroimaging measures that prove to be strongly predictive neuroimaging markers in pattern classification between healthy controls and general epileptic patients. These measures characterize two important aspects of the functional brain network in a quantitative manner: (i) coordinated operation among spatially distributed brain regions, and (ii) the asymmetry of bilaterally homologous brain regions, in terms of their global patterns of functional connectivity. This second measure offers a unique understanding of brain asymmetry at the network level, and, to the best of our knowledge, has not been previously used in pattern classification of functional brain networks. Using modern pattern-recognition approaches like sparse regression and support vector machine, we have achieved a cross-validated classification accuracy of 83.9% (specificity: 82.5%; sensitivity: 85%) across individuals from a large dataset consisting of 180 healthy controls and epileptic patients. We identified significantly changed functional pathways and subnetworks in epileptic patients that underlie the pathophysiological mechanism of the impaired cognitive functions. Specifically, we find that the asymmetry of brain operation for epileptic patients is markedly enhanced in temporal lobe and limbic system, in comparison with healthy individuals. The present study indicates that with specifically designed informative neuroimaging markers, resting-state fMRI can serve as a most promising tool for clinical diagnosis, and also shed light onto the physiology behind complex neuropsychiatric disorders. The systematic approaches we present here are expected to have wider applications in general neuropsychiatric disorders.

Zhang, ZhiQiang; Lu, WenLian; Lu, GuangMing; Feng, Jianfeng

2012-01-01

204

Structural and functional organization of a developing brain and formation of cognitive functions in child ontogeny  

Microsoft Academic Search

Results of multidisciplinary studies, including neuromorphological, neurophysiological, neuropsychological, and psychphysiological\\u000a studies, are reviewed. They allow the brain mechanisms of cognition formation and development during maturation to be identified.\\u000a The role of regulatory (modulatory) brain systems in forming the cognitive function in the child is demonstrated. Data on\\u000a considerable changes in the brain systems responsible for the development of cognitive functions

M. M. Bezrukikh; R. I. Machinskaya; D. A. Farber

2009-01-01

205

Transforming Growth Factor-? in Brain Functions and Dysfunctions  

Microsoft Academic Search

Transforming growth factor-?s (TGF-?s) belong to a superfamily of related peptides that play pivotal roles in intercellular\\u000a communication. Among these biological agents, TGF-?1 has been involved in a number of brain functions and dysfunctions throughout\\u000a life, ranging from neurogenesis to neurodegeneration. Animal models mimicking some aspects of human brain pathologies have\\u000a led to the idea that TGF-? may be a

Denis Vivien; Karim Benchenane; Carine Ali

206

Investigating brain dynamics and connectivity with functional MRI  

Microsoft Academic Search

Functional magnetic resonance imaging (fMRI) scans provide a record of ongoing neural processing through the measurement of changes in regional levels of blood oxygenation. While subjects are resting, fMRI has revealed networks of brain regions exhibiting synchronised 0.02-0.12 Hz fluctuations in spontaneous, low frequency brain activity. The physiology underlying these 'resting state' fluctuations is poorly understood. Our current research investigates

Eugene Duff; Gary Egan; Ross Cunnington; Iven Mareels; Binquan Wang; Peter Fox; Jinhu Xiong

2004-01-01

207

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.

Ernst, M.; Mueller, S.C.

2009-01-01

208

Functional magnetic resonance imaging (FMRI) of the human brain  

Microsoft Academic Search

Functional magnetic resonance imaging (FMRI) can provide detailed images of human brain that reflect localized changes in cerebral blood flow and oxygenation induced by sensory, motor, or cognitive tasks. This review presents methods for gradient-recalled echo-planar functional magnetic resonance imaging (FMRI). Also included is a discussion of the hypothesized basis of FMRI, imaging hardware, a unique visual stimulation apparatus, image

Edgar A. DeYoe; Peter Bandettini; Jay Neitz; David Miller; Paula Winans

1994-01-01

209

Resting-State Brain Organization Revealed by Functional Covariance Networks  

PubMed Central

Background Brain network studies using techniques of intrinsic connectivity network based on fMRI time series (TS-ICN) and structural covariance network (SCN) have mapped out functional and structural organization of human brain at respective time scales. However, there lacks a meso-time-scale network to bridge the ICN and SCN and get insights of brain functional organization. Methodology and Principal Findings We proposed a functional covariance network (FCN) method by measuring the covariance of amplitude of low-frequency fluctuations (ALFF) in BOLD signals across subjects, and compared the patterns of ALFF-FCNs with the TS-ICNs and SCNs by mapping the brain networks of default network, task-positive network and sensory networks. We demonstrated large overlap among FCNs, ICNs and SCNs and modular nature in FCNs and ICNs by using conjunctional analysis. Most interestingly, FCN analysis showed a network dichotomy consisting of anti-correlated high-level cognitive system and low-level perceptive system, which is a novel finding different from the ICN dichotomy consisting of the default-mode network and the task-positive network. Conclusion The current study proposed an ALFF-FCN approach to measure the interregional correlation of brain activity responding to short periods of state, and revealed novel organization patterns of resting-state brain activity from an intermediate time scale.

Wang, Zhengge; Yuan, Cuiping; Jiao, Qing; Chen, Huafu; Biswal, Bharat B.; Lu, Guangming; Liu, Yijun

2011-01-01

210

Functional imaging of dolphin brain metabolism and blood flow.  

PubMed

This report documents the first use of magnetic resonance images (MRIs) of living dolphins to register functional brain scans, allowing for the exploration of potential mechanisms of unihemispheric sleep. Diazepam has been shown to induce unihemispheric slow waves (USW), therefore we used functional imaging of dolphins with and without diazepam to observe hemispheric differences in brain metabolism and blood flow. MRIs were used to register functional brain scans with single photon emission computed tomography (SPECT) and positron emission tomography (PET) in trained dolphins. Scans using SPECT revealed unihemispheric blood flow reduction following diazepam doses greater than 0.55 mg kg(-1) for these 180-200 kg animals. Scans using PET revealed hemispheric differences in brain glucose consumption when scans with and without diazepam were compared. The findings suggest that unihemispheric reduction in blood flow and glucose metabolism in the hemisphere showing USW are important features of unihemispheric sleep. Functional scans may also help to elucidate the degree of hemispheric laterality of sensory and motor systems as well as in neurotransmitter or molecular mechanisms of unihemispheric sleep in delphinoid cetaceans. The findings also demonstrate the potential value of functional scans to explore other aspects of dolphin brain physiology as well as pathology. PMID:16857874

Ridgway, Sam; Houser, Dorian; Finneran, James; Carder, Don; Keogh, Mandy; Van Bonn, William; Smith, Cynthia; Scadeng, Miriam; Dubowitz, David; Mattrey, Robert; Hoh, Carl

2006-08-01

211

Functional MRI study of brain function under resting and activated states  

Microsoft Academic Search

Numerous magnetic resonance imaging (MRI) techniques have been developed with various imaging contrasts, which can be tightly linked to brain functions, electrophysiology and diseases. Recent MRI technology developments have resulted in several important functional MRI (fMRI) methods based on the blood oxygenation level dependent (BOLD) contrast. These fMRI methods have been applied to mapping brain activation in laminar level as

Wei Chen; Xiao Liu; Xiao-Hong Zhu; Nanyin Zhang

2009-01-01

212

Understanding and Treating Loss of Sense of Self Following Brain Injury: A Behavior Analytic Approach  

Microsoft Academic Search

Loss of sense of self is a common experience among acquired brain injury survivors. It involves conscious awareness on the part of the survivor that she is somehow not the same person as pre-injury, and is associated with emotionally distressing negative self-evaluations of post-injury changes in functioning. Denial of changes is a relatively common response among survivors who begin to

Stephen M. Myles

2004-01-01

213

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

214

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

215

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

PubMed Central

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.

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

2012-01-01

216

Investigation of acupoint specificity by whole brain functional connectivity analysis from fMRI data  

Microsoft Academic Search

Previous neuroimaging studies on acupuncture have primarily adopted functional connectivity analysis associated with one or a few preselected brain regions. Few have investigated how these brain regions interacted at the whole brain level. In this study, we sought to investigate the acupoint specificity by exploring the whole brain functional connectivity analysis on the post-stimulus resting brain modulated by acupuncture at

Yuanyuan Feng; Lijun Bai; Wensheng Zhang; Yanshuang Ren; Ting Xue; Hu Wang; Chongguang Zhong; Jie Tian

2011-01-01

217

Decreased Functional Brain Connectivity in Adolescents with Internet Addiction  

PubMed Central

Background Internet addiction has become increasingly recognized as a mental disorder, though its neurobiological basis is unknown. This study used functional neuroimaging to investigate whole-brain functional connectivity in adolescents diagnosed with internet addiction. Based on neurobiological changes seen in other addiction related disorders, it was predicted that connectivity disruptions in adolescents with internet addiction would be most prominent in cortico-striatal circuitry. Methods Participants were 12 adolescents diagnosed with internet addiction and 11 healthy comparison subjects. Resting-state functional magnetic resonance images were acquired, and group differences in brain functional connectivity were analyzed using the network-based statistic. We also analyzed network topology, testing for between-group differences in key graph-based network measures. Results Adolescents with internet addiction showed reduced functional connectivity spanning a distributed network. The majority of impaired connections involved cortico-subcortical circuits (?24% with prefrontal and ?27% with parietal cortex). Bilateral putamen was the most extensively involved subcortical brain region. No between-group difference was observed in network topological measures, including the clustering coefficient, characteristic path length, or the small-worldness ratio. Conclusions Internet addiction is associated with a widespread and significant decrease of functional connectivity in cortico-striatal circuits, in the absence of global changes in brain functional network topology.

Hong, Soon-Beom; Zalesky, Andrew; Cocchi, Luca; Fornito, Alex; Choi, Eun-Jung; Kim, Ho-Hyun; Suh, Jeong-Eun; Kim, Chang-Dai; Kim, Jae-Won; Yi, Soon-Hyung

2013-01-01

218

Reorganization of functional brain networks during the recovery of stroke: a functional MRI study.  

PubMed

Studies have demonstrated that reorganization of the cortex after stroke contributed to the recovery of motor function. However, these studies paid much more attention to the reorganization of motor-related brain regions and motor executive network which only contained tens of brain regions, ignoring the change in brain-wide network during the restoration of motor function. Based on this consideration, this paper investigated the functional reorganization of brain-wide network during the recovery after stroke from the perspective of graph theory. At four time points (less than 10 days, around 2 weeks, 1 month and 3 months) after stroke onset, we obtained the functional MRI (fMRI) data of stroke patients when they were doing finger tapping task. Based on the fMRI data, we constructed the brain-wide functional network which consisted of 264 putative functional areas for each subject at each time point. Then the topological parameters (e.g., characteristic path length and cluster coefficient) of these brain networks were examined. Results showed that the brain networks shifted towards a non-optimal topological configuration with low small-worldness during the process of recovery. And this finding may broaden our knowledge about the reorganization of brain function during recovery after stroke. PMID:23366837

Cheng, Lin; Wu, Zhiyuan; Fu, Yi; Miao, Fei; Sun, Junfeng; Tong, Shanbao

2012-01-01

219

Physiological functions for brain NF-?B  

Microsoft Academic Search

Members of the nuclear factor kB (NF-kB) family of transcription factors are activated within the CNS in pathological settings of apoptosis and neurological disease. Recent work using several model systems provides accumulating evidence that these transcription factors also participate in the regulation of neuronal activity-dependent transcription and behavior under physiological conditions. This review highlights advances in our understanding of the

Mollie K. Meffert; David Baltimore

2005-01-01

220

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

221

Neurocognitive Function of Patients with Brain Metastasis Who Received Either Whole Brain Radiotherapy Plus Stereotactic Radiosurgery or Radiosurgery Alone  

Microsoft Academic Search

Purpose: To determine how the omission of whole brain radiotherapy (WBRT) affects the neurocognitive function of patients with one to four brain metastases who have been treated with stereotactic radiosurgery (SRS). Methods and Materials: In a prospective randomized trial between WBRT+SRS and SRS alone for patients with one to four brain metastases, we assessed the neurocognitive function using the Mini-Mental

Hidefumi. Aoyama; Masao Tago; Norio Kato; Tatsuya Toyoda; Masahiro Kenjyo; Saeko Hirota; Hiroki Shioura; Taisuke Inomata; Etsuo Kunieda; Kazushige Hayakawa; Keiichi Nakagawa; Gen Kobashi; Hiroki Shirato

2007-01-01

222

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

223

Changes in Topological Organization of Functional PET Brain Network with Normal Aging  

PubMed Central

Recent studies about brain network have suggested that normal aging is associated with alterations in coordinated patterns of the large-scale brain functional and structural systems. However, age-related changes in functional networks constructed via positron emission tomography (PET) data are still barely understood. Here, we constructed functional brain networks composed of regions in younger (mean age years) and older (mean age years) age groups with PET data. younger and older healthy individuals were separately selected for two age groups, from a physical examination database. Corresponding brain functional networks of the two groups were constructed by thresholding average cerebral glucose metabolism correlation matrices of regions and analysed using graph theoretical approaches. Although both groups showed normal small-world architecture in the PET networks, increased clustering and decreased efficiency were found in older subjects, implying a degeneration process that brain system shifts from a small-world network to regular one along with normal aging. Moreover, normal senescence was related to changed nodal centralities predominantly in association and paralimbic cortex regions, e.g. increasing in orbitofrontal cortex (middle) and decreasing in left hippocampus. Additionally, the older networks were about equally as robust to random failures as younger counterpart, but more vulnerable against targeted attacks. Finally, methods in the construction of the PET networks revealed reasonable robustness. Our findings enhanced the understanding about the topological principles of PET networks and changes related to normal aging.

Liu, Huafeng; Huang, Wenhua; Hu, Zhenghui

2014-01-01

224

Lateral brain function in normal and disordered emotion: interpreting electroencephalographic evidence.  

PubMed

Given the developing awareness of the lateral specialization of the human brain for both cognitive and emotional processes, the recent findings of characteristic hemispheric asymmetries in psychopathological groups suggests a neuropsychological model may be explanatory for abnormal psychology. Since the activity of arousal systems of the brain is a primary issue in interpreting both biochemical abnormalities and thought disorders in psychopathology, electroencephalographic (EEG) measures of cortical arousal are relevant. A better understanding of the relation of EEG measures to normal emotional arousal and cognitive effort may facilitate interpretation of the functional significance of EEG asymmetries in psychopathology. PMID:6525383

Tucker, D M

1984-12-01

225

Disrutpted 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.

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

226

Neuroanatomical substrates of action perception and understanding: an anatomic likelihood estimation meta-analysis of lesion-symptom mapping studies in brain injured patients  

PubMed Central

Several neurophysiologic and neuroimaging studies suggested that motor and perceptual systems are tightly linked along a continuum rather than providing segregated mechanisms supporting different functions. Using correlational approaches, these studies demonstrated that action observation activates not only visual but also motor brain regions. On the other hand, brain stimulation and brain lesion evidence allows tackling the critical question of whether our action representations are necessary to perceive and understand others’ actions. In particular, recent neuropsychological studies have shown that patients with temporal, parietal, and frontal lesions exhibit a number of possible deficits in the visual perception and the understanding of others’ actions. The specific anatomical substrates of such neuropsychological deficits however, are still a matter of debate. Here we review the existing literature on this issue and perform an anatomic likelihood estimation meta-analysis of studies using lesion-symptom mapping methods on the causal relation between brain lesions and non-linguistic action perception and understanding deficits. The meta-analysis encompassed data from 361 patients tested in 11 studies and identified regions in the inferior frontal cortex, the inferior parietal cortex and the middle/superior temporal cortex, whose damage is consistently associated with poor performance in action perception and understanding tasks across studies. Interestingly, these areas correspond to the three nodes of the action observation network that are strongly activated in response to visual action perception in neuroimaging research and that have been targeted in previous brain stimulation studies. Thus, brain lesion mapping research provides converging causal evidence that premotor, parietal and temporal regions play a crucial role in action recognition and understanding.

Urgesi, Cosimo; Candidi, Matteo; Avenanti, Alessio

2014-01-01

227

Neuroanatomical substrates of action perception and understanding: an anatomic likelihood estimation meta-analysis of lesion-symptom mapping studies in brain injured patients.  

PubMed

Several neurophysiologic and neuroimaging studies suggested that motor and perceptual systems are tightly linked along a continuum rather than providing segregated mechanisms supporting different functions. Using correlational approaches, these studies demonstrated that action observation activates not only visual but also motor brain regions. On the other hand, brain stimulation and brain lesion evidence allows tackling the critical question of whether our action representations are necessary to perceive and understand others' actions. In particular, recent neuropsychological studies have shown that patients with temporal, parietal, and frontal lesions exhibit a number of possible deficits in the visual perception and the understanding of others' actions. The specific anatomical substrates of such neuropsychological deficits however, are still a matter of debate. Here we review the existing literature on this issue and perform an anatomic likelihood estimation meta-analysis of studies using lesion-symptom mapping methods on the causal relation between brain lesions and non-linguistic action perception and understanding deficits. The meta-analysis encompassed data from 361 patients tested in 11 studies and identified regions in the inferior frontal cortex, the inferior parietal cortex and the middle/superior temporal cortex, whose damage is consistently associated with poor performance in action perception and understanding tasks across studies. Interestingly, these areas correspond to the three nodes of the action observation network that are strongly activated in response to visual action perception in neuroimaging research and that have been targeted in previous brain stimulation studies. Thus, brain lesion mapping research provides converging causal evidence that premotor, parietal and temporal regions play a crucial role in action recognition and understanding. PMID:24910603

Urgesi, Cosimo; Candidi, Matteo; Avenanti, Alessio

2014-01-01

228

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

229

SSVEP Response Is Related to Functional Brain Network Topology Entrained by the Flickering Stimulus  

PubMed Central

Previous studies have shown that the brain network topology correlates with the cognitive function. However, few studies have investigated the relationship between functional brain networks that process sensory inputs and outputs. In this study, we focus on steady-state paradigms using a periodic visual stimulus, which are increasingly being used in both brain-computer interface (BCI) and cognitive neuroscience researches. Using the graph theoretical analysis, we investigated the relationship between the topology of functional networks entrained by periodic stimuli and steady state visually evoked potentials (SSVEP) using two frequencies and eleven subjects. First, the entire functional network (Network 0) of each frequency for each subject was constructed according to the coherence between electrode pairs. Next, Network 0 was divided into three sub-networks, in which the connection strengths were either significantly (positively for Network 1, negatively for Network 3) or non-significantly (Network 2) correlated with the SSVEP responses. Our results revealed that the SSVEP responses were positively correlated to the mean functional connectivity, clustering coefficient, and global and local efficiencies, while these responses were negatively correlated with the characteristic path length of Networks 0, 1 and 2. Furthermore, the strengths of these connections that significantly correlated with the SSVEP (both positively and negatively) were mainly found to be long-range connections between the parietal-occipital and frontal regions. These results indicate that larger SSVEP responses correspond with better functional network topology structures. This study may provide new insights for understanding brain mechanisms when using SSVEPs as frequency tags.

Zhang, Yangsong; Xu, Peng; Huang, Yingling; Cheng, Kaiwen; Yao, Dezhong

2013-01-01

230

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

Microsoft Academic Search

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,

Jing Li; Soren M. Bentzen; Jialiang Li; Markus Renschler; Minesh P. Mehta

2008-01-01

231

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.

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

232

Metabolism of exogenous sex steroids and effect on brain functions with a focus on tibolone  

Microsoft Academic Search

Around the menopause, changes in ovarian secretion of steroids result in changes in brain function: hot flushes and sweating later followed by changes in mood, libido and cognition. The relationship between sex steroids and brain functions are reviewed, with focus on hormonal treatments, in particular tibolone, on the postmenopausal brain and on associations between tissue levels and brain functions. Data

H. A. M. Verheul; H. J. Kloosterboer

2006-01-01

233

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.

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

234

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.

Zimerman, Maximo; Hummel, Friedhelm C.

2010-01-01

235

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

ERIC Educational Resources Information Center

Neuroimaging findings which identify normal brain development trajectories are presented. Results show that early brain development begins with the neural tube formation and ends with myelintation. How disturbances in brain development patterns are related to childhood psychiatric disorders is examined.

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

2008-01-01

236

Relationship between muscle output and functional MRI-measured brain activation  

Microsoft Academic Search

.   The relationship between functional MRI (fMRI)-measured brain signal and muscle force and or electromyogram (EMG) is critical\\u000a in interpreting fMRI data and understanding the control mechanisms of voluntary motor actions. We designed a system that could\\u000a record joint force and surface EMG online with fMRI data. High-quality force and EMG data were obtained while maintaining\\u000a the quality of the

Te H. Dai; Jing Z. Liu; Vinod Sahgal; Robert W. Brown; Guang H. Yue

2001-01-01

237

Sex Differences in the Brain: the Relation between Structure and Function  

PubMed Central

In the fifty years since the organizational hypothesis was proposed, many sex differences have been found in behavior as well as structure of the brain that depend on the organizational effects of gonadal hormones early in development. Remarkably, in most cases we do not understand how the two are related. This paper makes the case that overstating the magnitude or constancy of sex differences in behavior and too narrowly interpreting the functional consequences of structural differences are significant roadblocks in resolving this issue.

de Vries, Geert J.; Sodersten, Per

2014-01-01

238

Comparing accuracy of knowledge of functional effects of schizophrenia and brain injury.  

PubMed

This study developed and validated the Brain Injury and Schizophrenia Awareness Scale (BISAS) to compare accuracy of knowledge of functional effects of schizophrenia and TBI. The BISAS displayed good internal consistency and evidence of construct validity. Overall, general community participants (n=143) lacked understanding of the shared effects of these conditions, and attributed emotional and behavioural deficits to schizophrenia and cognitive deficits to TBI. PMID:24889843

McKendry, Yvette; Ownsworth, Tamara; Bettens, Gemma F

2014-09-30

239

HIV and Aging Independently Affect Brain Function as Measured by Functional Magnetic Resonance Imaging  

PubMed Central

We investigated interactions between HIV and aging on brain function demands using functional magnetic resonance imaging (fMRI). A multiple regression model studied the association and interaction between fMRI measures, HIV serostatus, and age for 26 HIV infected (HIV+) and 25 seronegative (HIV?) subjects. While HIV serostatus and age independently affected fMRI measures, no interaction occurred. Functional brain demands in HIV+ subjects were equivalent to ~15–20 year older HIV? subjects. Frailty parallels between HIV and aging could result from continued immunological challenges depleting resources and triggering increased metabolic demands. fMRI could be a non-invasive biomarker to assess HIV in the brain.

Ances, Beau M.; Vaida, Florin; Yeh, Melinda J.; Liang, Christine L.; Buxton, Richard B.; Letendre, Scott; McCutchan, J. Allen; Ellis, Ronald J.

2009-01-01

240

Altered Resting Brain Function and Structure in Professional Badminton Players  

PubMed Central

Abstract Neuroimaging studies of professional athletic or musical training have demonstrated considerable practice-dependent plasticity in various brain structures, which may reflect distinct training demands. In the present study, structural and functional brain alterations were examined in professional badminton players and compared with healthy controls using magnetic resonance imaging (MRI) and resting-state functional MRI. Gray matter concentration (GMC) was assessed using voxel-based morphometry (VBM), and resting-brain functions were measured by amplitude of low-frequency fluctuation (ALFF) and seed-based functional connectivity. Results showed that the athlete group had greater GMC and ALFF in the right and medial cerebellar regions, respectively. The athlete group also demonstrated smaller ALFF in the left superior parietal lobule and altered functional connectivity between the left superior parietal and frontal regions. These findings indicate that badminton expertise is associated with not only plastic structural changes in terms of enlarged gray matter density in the cerebellum, but also functional alterations in fronto-parietal connectivity. Such structural and functional alterations may reflect specific experiences of badminton training and practice, including high-capacity visuo-spatial processing and hand-eye coordination in addition to refined motor skills.

Di, Xin; Zhu, Senhua; Wang, Pin; Ye, Zhuoer; Zhou, Ke; Zhuo, Yan

2012-01-01

241

Altered resting brain function and structure in professional badminton players.  

PubMed

Neuroimaging studies of professional athletic or musical training have demonstrated considerable practice-dependent plasticity in various brain structures, which may reflect distinct training demands. In the present study, structural and functional brain alterations were examined in professional badminton players and compared with healthy controls using magnetic resonance imaging (MRI) and resting-state functional MRI. Gray matter concentration (GMC) was assessed using voxel-based morphometry (VBM), and resting-brain functions were measured by amplitude of low-frequency fluctuation (ALFF) and seed-based functional connectivity. Results showed that the athlete group had greater GMC and ALFF in the right and medial cerebellar regions, respectively. The athlete group also demonstrated smaller ALFF in the left superior parietal lobule and altered functional connectivity between the left superior parietal and frontal regions. These findings indicate that badminton expertise is associated with not only plastic structural changes in terms of enlarged gray matter density in the cerebellum, but also functional alterations in fronto-parietal connectivity. Such structural and functional alterations may reflect specific experiences of badminton training and practice, including high-capacity visuo-spatial processing and hand-eye coordination in addition to refined motor skills. PMID:22840241

Di, Xin; Zhu, Senhua; Jin, Hua; Wang, Pin; Ye, Zhuoer; Zhou, Ke; Zhuo, Yan; Rao, Hengyi

2012-01-01

242

The brains of high functioning autistic individuals do not synchronize with those of others?  

PubMed Central

Multifaceted and idiosyncratic aberrancies in social cognition characterize autism spectrum disorders (ASDs). To advance understanding of underlying neural mechanisms, we measured brain hemodynamic activity with functional magnetic resonance imaging (fMRI) in individuals with ASD and matched-pair neurotypical (NT) controls while they were viewing a feature film portraying social interactions. Pearson's correlation coefficient was used as a measure of voxelwise similarity of brain activity (InterSubject Correlations—ISCs). Individuals with ASD showed lower ISC than NT controls in brain regions implicated in processing social information including the insula, posterior and anterior cingulate cortex, caudate nucleus, precuneus, lateral occipital cortex, and supramarginal gyrus. Curiously, also within NT group, autism-quotient scores predicted ISC in overlapping areas, including, e.g., supramarginal gyrus and precuneus. In ASD participants, functional connectivity was decreased between the frontal pole and the superior frontal gyrus, angular gyrus, superior parietal lobule, precentral gyrus, precuneus, and anterior/posterior cingulate gyrus. Taken together these results suggest that ISC and functional connectivity measure distinct features of atypical brain function in high-functioning autistic individuals during free viewing of acted social interactions. Our ISC results suggest that the minds of ASD individuals do not ‘tick together’ with others while perceiving identical dynamic social interactions.

Salmi, J.; Roine, U.; Glerean, E.; Lahnakoski, J.; Nieminen-von Wendt, T.; Tani, P.; Leppamaki, S.; Nummenmaa, L.; Jaaskelainen, I.P.; Carlson, S.; Rintahaka, P.; Sams, M.

2013-01-01

243

Left Brain vs. Right Brain: Findings on Visual Spatial Capacities and the Functional Neurology of Giftedness  

ERIC Educational Resources Information Center

As neuroimaging technologies increase their sensitivity to assess the function of the human brain and results from these studies draw the attention of educators, it becomes paramount to identify misconceptions about what these data illustrate and how these findings might be applied to educational contexts. Some of these "neuromyths" have…

Kalbfleisch, M. Layne; Gillmarten, Charles

2013-01-01

244

Abnormal Brain Functional Connectivity of the Hypothalamus in Cluster Headaches  

PubMed Central

The aim of this study was to detect the abnormality of the brain functional connectivity of the hypothalamus during acute spontaneous cluster headache (CH) attacks (‘in attack’) and headache-free intervals (‘out of attack’) using resting-state functional magnetic resonance imaging (RS-fMRI) technique. The RS-fMRI data from twelve male CH patients during ‘in attack’ and ‘out of attack’ periods and twelve age- and sex-matched normal controls were analyzed by the region-of-interest -based functional connectivity method using SPM5 software. Abnormal brain functional connectivity of the hypothalamus is present in CH, which is located mainly in the pain system during the spontaneous CH attacks. It extends beyond the pain system during CH attack intervals.

Qiu, Enchao; Wang, Yan; Ma, Lin; Tian, Lixia; Liu, Ruozhuo; Dong, Zhao; Xu, Xian; Zou, Zhitong; Yu, Shengyuan

2013-01-01

245

Brain miner: a 3D visual interface for the investigation of functional relationships in the brain  

NASA Astrophysics Data System (ADS)

Brain imaging methods used in experimental brain research such as Positron Emission Tomography (PET) and Functional Magnetic Resonance (fMRI) require the analysis of large amounts of data. Statistical methods are necessary to obtain a reliable measure of a given effect. Typically, researchers report their findings by listing those regions which show significant statistical activity in a group of subjects under some experimental condition or task. A number of methods create statistical parametric maps (SPMs) of the brain on a voxel- basis. However, a major limitation of the voxel-based technique is the inaccuracy of the transformation into a stereotaxic space (e.g., Talairach-Tournoux) given the wide variability in human brain structure. In order to account for this, researchers have turned to computing the statistics not on individual voxels but on predefined anatomical regions-of- interest (ROIs). A correlation coefficient is used to quantify similarity in response for various regions during an experimental setting. Since the functional inter-relationships can become rather complex, they are best understood in the context of the underlying 3-D brain anatomy. In this paper, we present a novel 3-D interface that allows the interactive exploration of the correlation datasets within a common stereotaxic atlas.

Welsh, Tom F.; Mueller, Klaus D.; Zhu, Wei; Meade, Jeffrey R.; Volkow, Nora

2001-05-01

246

Tai Chi Chuan optimizes the functional organization of the intrinsic human brain architecture in older adults.  

PubMed

Whether Tai Chi Chuan (TCC) can influence the intrinsic functional architecture of the human brain remains unclear. To examine TCC-associated changes in functional connectomes, resting-state functional magnetic resonance images were acquired from 40 older individuals including 22 experienced TCC practitioners (experts) and 18 demographically matched TCC-naïve healthy controls, and their local functional homogeneities across the cortical mantle were compared. Compared to the controls, the TCC experts had significantly greater and more experience-dependent functional homogeneity in the right post-central gyrus (PosCG) and less functional homogeneity in the left anterior cingulate cortex (ACC) and the right dorsal lateral prefrontal cortex. Increased functional homogeneity in the PosCG was correlated with TCC experience. Intriguingly, decreases in functional homogeneity (improved functional specialization) in the left ACC and increases in functional homogeneity (improved functional integration) in the right PosCG both predicted performance gains on attention network behavior tests. These findings provide evidence for the functional plasticity of the brain's intrinsic architecture toward optimizing locally functional organization, with great implications for understanding the effects of TCC on cognition, behavior and health in aging population. PMID:24860494

Wei, Gao-Xia; Dong, Hao-Ming; Yang, Zhi; Luo, Jing; Zuo, Xi-Nian

2014-01-01

247

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

248

Human brain somatic representation: a functional magnetic resonance mapping  

NASA Astrophysics Data System (ADS)

Central nervous system studies of injury and plasticity for the reorganization in the phantom limb sensation area presented. In particular functional magnetic resonance imaging (fMRI) mapping of the somatic and motor cortex of amputee patients, in the case of referred sensations. Using fMRI we can show the correlation between structure and functional field and study the reorganization due to plasticity in the brain. .

Romero-Romo, Juan; Rojas, Rafael; Salgado, Perla; Sánchez-Cortázar, Julián; Vazquez-Vela, Arturo; Barrios, Fernando A.

2001-10-01

249

Anatomical and functional assemblies of brain BOLD oscillations  

PubMed Central

Brain oscillatory activity has long been thought to have spatial properties, the details of which are unresolved. Here we examine spatial organizational rules for the human brain oscillatory activity as measured by blood oxygen level-dependent (BOLD). Resting state BOLD signal was transformed into frequency space (Welch’s method), averaged across subjects, and its spatial distribution studied as a function of four frequency bands, spanning the full bandwidth of BOLD. The brain showed anatomically constrained distribution of power for each frequency band. This result was replicated on a repository dataset of 195 subjects. Next, we examined larger-scale organization by parceling the neocortex into regions approximating Brodmann Areas (BAs). This indicated that BAs of simple function/connectivity (unimodal), vs. complex properties (transmodal), are dominated by low frequency BOLD oscillations, and within the visual ventral stream we observe a graded shift of power to higher frequency bands for BAs further removed from the primary visual cortex (increased complexity), linking frequency properties of BOLD to hodology. Additionally, BOLD oscillation properties for the default mode network demonstrated that it is composed of distinct frequency dependent regions. When the same analysis was performed on a visual-motor task, frequency-dependent global and voxel-wise shifts in BOLD oscillations could be detected at brain sites mostly outside those identified with general linear modeling. Thus, analysis of BOLD oscillations in full bandwidth uncovers novel brain organizational rules, linking anatomical structures and functional networks to characteristic BOLD oscillations. The approach also identifies changes in brain intrinsic properties in relation to responses to external inputs.

Baria, Alexis T.; Baliki, Marwan N.; Parrish, Todd; Apkarian, A. Vania

2011-01-01

250

From pattern to purpose: how comparative studies contribute to understanding the function of adult neurogenesis.  

PubMed

The study of adult neurogenesis has had an explosion of fruitful growth. Yet numerous uncertainties and challenges persist. Our review begins with a survey of species that show evidence of adult neurogenesis. We then discuss how neurogenesis varies across brain regions and point out that regional specializations can indicate functional adaptations. Lifespan and aging are key life-history traits. Whereas 'adult neurogenesis' is the common term in the literature, it does not reflect the reality of neurogenesis being primarily a 'juvenile' phenomenon. We discuss the sharp decline with age as a universal trait of neurogenesis with inevitable functional consequences. Finally, the main body of the review focuses on the function of neurogenesis in birds and mammals. Selected examples illustrate how our understanding of avian and mammalian neurogenesis can complement each other. It is clear that although the two phyla have some common features, the function of adult neurogenesis may not be similar between them and filling the gaps will help us understand neurogenesis as an evolutionarily conserved trait to meet particular ecological pressures. PMID:21929628

Barker, Jennifer M; Boonstra, Rudy; Wojtowicz, Jan Martin

2011-09-01

251

Phospholipase D in brain function and Alzheimer's disease  

PubMed Central

Alzheimer’s disease is the most common neurodegenerative disorder. Although lipids are major constituents of brain, their role in Alzheimer’s disease pathogenesis is poorly understood. Much attention has been given to cholesterol, but growing evidence suggests that other lipids, such as phospholipids, might play an important role in this disorder. In this review, we will summarize the evidence linking phospholipase D, a phosphatidic acid-synthesizing enzyme, to multiple aspects of normal brain function and to Alzheimer’s disease. The role of phospholipase D in signaling mechanisms downstream of beta-amyloid as well as in the trafficking and processing of amyloid precursor protein will be emphasized.

Oliveira, Tiago Gil; Di Paolo, Gilbert

2012-01-01

252

Reentry: a key mechanism for integration of brain function  

PubMed Central

Reentry in nervous systems is the ongoing bidirectional exchange of signals along reciprocal axonal fibers linking two or more brain areas. The hypothesis that reentrant signaling serves as a general mechanism to couple the functioning of multiple areas of the cerebral cortex and thalamus was first proposed in 1977 and 1978 (Edelman, 1978). A review of the amount and diversity of supporting experimental evidence accumulated since then suggests that reentry is among the most important integrative mechanisms in vertebrate brains (Edelman, 1993). Moreover, these data prompt testable hypotheses regarding mechanisms that favor the development and evolution of reentrant neural architectures.

Edelman, Gerald M.; Gally, Joseph A.

2013-01-01

253

Dynamic regulation of NMDAR function in the adult brain by the stress hormone corticosterone  

PubMed Central

Stress and corticosteroids dynamically modulate the expression of synaptic plasticity at glutamatergic synapses in the developed brain. Together with alpha-amino-3-hydroxy-methyl-4-isoxazole propionic acid receptors (AMPAR), N-methyl-D-aspartate receptors (NMDAR) are critical mediators of synaptic function and are essential for the induction of many forms of synaptic plasticity. Regulation of NMDAR function by cortisol/corticosterone (CORT) may be fundamental to the effects of stress on synaptic plasticity. Recent reports of the efficacy of NMDAR antagonists in treating certain stress-associated psychopathologies further highlight the importance of understanding the regulation of NMDAR function by CORT. Knowledge of how corticosteroids regulate NMDAR function within the adult brain is relatively sparse, perhaps due to a common belief that NMDAR function is stable in the adult brain. We review recent results from our laboratory and others demonstrating dynamic regulation of NMDAR function by CORT in the adult brain. In addition, we consider the issue of how differences in the early life environment may program differential sensitivity to modulation of NMDAR function by CORT and how this may influence synaptic function during stress. Findings from these studies demonstrate that NMDAR function in the adult hippocampus remains sensitive to even brief exposures to CORT and that the capacity for modulation of NMDAR may be programmed, in part, by the early life environment. Modulation of NMDAR function may contribute to dynamic regulation of synaptic plasticity and adaptation in the face of stress, however, enhanced NMDAR function may be implicated in mechanisms of stress-related psychopathologies including depression.

Tse, Yiu Chung; Bagot, Rosemary C.; Wong, Tak Pan

2012-01-01

254

Towards new understanding of the heart structure and function.  

PubMed

Structure and function in any organ are inseparable categories, both in health and disease. Whether we are ready to accept, or not, many questions in cardiovascular medicine are still pending, due to our insufficient insight in the basic science. Even so, any new concept encounters difficulties, mainly arising from our inert attitude, which may result either in unjustified acceptance or denial. The ventricular myocardial band concept, developed over the last 50 years, has revealed unavoidable coherence and mutual coupling of form and function in the ventricular myocardium. After more than five centuries long debate on macroscopic structure of the ventricular myocardium, this concept has provided a promising ground for its final understanding. Recent validations of the ventricular myocardial band, reviewed here, as well as future research directions that are pointed out, should initiate much wider scientific interest, which would, in turn, lead to reconciliation of some exceeded concepts about developmental, electrical, mechanical and energetical events in human heart. The benefit of this, of course, would be the most evident in the clinical arena. PMID:15691670

Torrent-Guasp, Francisco; Kocica, Mladen J; Corno, Antonio F; Komeda, Masashi; Carreras-Costa, Francesc; Flotats, A; Cosin-Aguillar, Juan; Wen, Han

2005-02-01

255

Restoration of function after brain damage using a neural prosthesis.  

PubMed

Neural interface systems are becoming increasingly more feasible for brain repair strategies. This paper tests the hypothesis that recovery after brain injury can be facilitated by a neural prosthesis serving as a communication link between distant locations in the cerebral cortex. The primary motor area in the cerebral cortex was injured in a rat model of focal brain injury, disrupting communication between motor and somatosensory areas and resulting in impaired reaching and grasping abilities. After implantation of microelectrodes in cerebral cortex, a neural prosthesis discriminated action potentials (spikes) in premotor cortex that triggered electrical stimulation in somatosensory cortex continuously over subsequent weeks. Within 1 wk, while receiving spike-triggered stimulation, rats showed substantially improved reaching and grasping functions that were indistinguishable from prelesion levels by 2 wk. Post hoc analysis of the spikes evoked by the stimulation provides compelling evidence that the neural prosthesis enhanced functional connectivity between the two target areas. This proof-of-concept study demonstrates that neural interface systems can be used effectively to bridge damaged neural pathways functionally and promote recovery after brain injury. PMID:24324155

Guggenmos, David J; Azin, Meysam; Barbay, Scott; Mahnken, Jonathan D; Dunham, Caleb; Mohseni, Pedram; Nudo, Randolph J

2013-12-24

256

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.

McGraw, Lisa A.; Young, Larry J.

2009-01-01

257

Functional Brain Image Analysis Using Joint Function-Structure Priors  

PubMed Central

We propose a new method for context-driven analysis of functional magnetic resonance images (fMRI) that incorporates spatial relationships between functional parameter clusters and anatomical structure directly for the first time. We design a parametric scheme that relates functional and structural spatially-compact regions in a single unified manner. Our method is motivated by the fact that the fMRI and anatomical MRI (aMRI) have consistent relations that provide configurations and context that aid in fMRI analysis. We develop a statistical decision-making strategy to estimate new fMRI parameter images (based on a General Linear Model-GLM) and spatially-clustered zones within these images. The analysis is based on the time-series data and contextual information related to appropriate spatial grouping of parameters in the functional data and the relationship of this grouping to relevant gray matter structure from the anatomical data. We introduce a representation for the joint prior of the functional and structural information, and define a joint probability distribution over the variations of functional clusters and the related structure contained in a set of training images. We estimate the Maximum A Posteriori (MAP) functional parameters, formulating the function-structure model in terms of level set functions. Results from 3D fMRI and aMRI show that this context-driven analysis potentially extracts more meaningful information than the standard GLM approach.

Yang, Jing; Papademetris, Xenophon; Staib, Lawrence H.; Schultz, Robert T.; Duncan, James S.

2010-01-01

258

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

259

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.

Olsen, Shawn R.; Wilson, Rachel I.

2010-01-01

260

Neuroergonomics - Analyzing Brain Function to Enhance Human Performance in Complex Systems.  

National Technical Information Service (NTIS)

Why Neuroergonomics. To design effective human-machine systems, we must (1) Understand mind in relation to work and technology -- ergonomics (2) Mind cannot be understood without studying the brain -- neuroscience (3) Hence study brain and mind in complex...

R. Parasuraman

2008-01-01

261

Intestinal barrier function and the brain-gut axis.  

PubMed

The luminal-mucosal interface of the intestinal tract is the first relevant location where microorganism-derived antigens and all other potentially immunogenic particles face the scrutiny of the powerful mammalian immune system. Upon regular functioning conditions, the intestinal barrier is able to effectively prevent most environmental and external antigens to interact openly with the numerous and versatile elements that compose the mucosal-associated immune system. This evolutionary super system is capable of processing an astonishing amount of antigens and non-immunogenic particles, approximately 100 tons in one individual lifetime, only considering food-derived components. Most important, to develop oral tolerance and proper active immune responses needed to prevent disease and inflammation, this giant immunogenic load has to be managed in a way that physiological inflammatory balance is constantly preserved. Adequate functioning of the intestinal barrier involves local and distant regulatory networks integrating the so-called brain-gut axis. Along this complex axis both brain and gut structures participate in the processing and execution of response signals to external and internal changes coming from the digestive tract, using multidirectional pathways to communicate. Dysfunction of brain-gut axis facilitates malfunctioning of the intestinal barrier, and vice versa, increasing the risk of uncontrolled immunological reactions that may trigger mucosal and brain low-grade inflammation, a putative first step to the initiation of more permanent gut disorders. In this chapter, we describe the structure, function and interactions of intestinal barrier, microbiota and brain-gut axis in both healthy and pathological conditions. PMID:24997030

Alonso, Carmen; Vicario, María; Pigrau, Marc; Lobo, Beatriz; Santos, Javier

2014-01-01

262

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

263

A multidimensional approach to understanding floral function and form.  

PubMed

• Premise of the study: Variation in plant mating systems is a fundamental component of the diversity of floral form and function. Mating systems have a strong influence on the distribution and expression of genetic variation, which in turn can influence the course of mating system evolution. It has long been appreciated, however, that ecological interactions may provide much of the impetus behind these evolutionary changes. • Methods: This commentary reviews the Special Section in the American Journal of Botany (vol. 100, issue 6) that features novel research on the role of interactions between plants and their pollinators, seed dispersers, herbivores, and interspecific competitors in the evolution of selfing rates and gender. These studies vary in approach from empirical experiments, to phylogenetic comparisons, to theoretical models, to literature reviews as they each attempt to shed new light on longstanding questions about the selective forces and evolutionary pathways that have led to the diversified means by which plants promote or discourage self-fertilization. • Key results: Evidence is provided that indicates that ecological interactions (e.g., herbivory and heterospecific pollen deposition by pollinators) can strongly influence the relative advantages of selfing and outcrossing. Ecological interactions can also influence allocation to sexual functions, which will influence individual and population outcrossing rates and possibly the evolutionary path of gender expression. • Conclusions: Mating systems evolution is clearly a multidimensional problem. Research that places the study of mating and sexual systems within a more realistic ecological context will no doubt reveal more complexity as we move toward a better understanding of plant diversity. PMID:23720428

Carr, David E

2013-06-01

264

Developmental changes in brain activation and functional connectivity during response inhibition in the early childhood brain.  

PubMed

Response inhibition is an attention function which develops relatively early during childhood. Behavioral data suggest that by the age of 3, children master the basic task requirements for the assessment of response inhibition but performance improves substantially until the age of 7. The neuronal mechanisms underlying these developmental processes, however, are not well understood. In this study, we examined brain activation patterns and behavioral performance of children aged between 4 and 6 years compared to adults by applying a go/no-go paradigm during near-infrared spectroscopy (NIRS) brain imaging. We furthermore applied task-independent functional connectivity measures to the imaging data to identify maturation of intrinsic neural functional networks. We found a significant group×condition related interaction in terms of inhibition-related reduced right fronto-parietal activation in children compared to adults. In contrast, motor-related activation did not differ between age groups. Functional connectivity analysis revealed that in the children's group, short-range coherence within frontal areas was stronger, and long-range coherence between frontal and parietal areas was weaker, compared to adults. Our findings show that in children aged from 4 to 6 years fronto-parietal brain maturation plays a crucial part in the cognitive development of response inhibition. PMID:23265620

Mehnert, Jan; Akhrif, Atae; Telkemeyer, Silke; Rossi, Sonja; Schmitz, Christoph H; Steinbrink, Jens; Wartenburger, Isabell; Obrig, Hellmuth; Neufang, Susanne

2013-11-01

265

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

266

Executive functioning and adaptive living skills after acquired brain injury.  

PubMed

Executive dysfunction is common following brain injury, with impairments involving attention, social pragmatics, higher-order thinking, judgment, and reasoning. Executive function impairments may have a direct impact on an individual's ability to return to instrumental activities of daily living (IADL), including employment, money management, driving, and maintaining a residence. Research has shown that neuropsychological executive function measures may be able to predict daily-living skills. There is limited research evaluating the relationship between executive functions and IADLs in adults with acquired brain injuries (ABI), with none investigating levels of proficiency as related to specific test scores. We hypothesize that neuropsychological executive function measures will have significant and moderate-to-strong correlations with participant-rated proficiency on functional tasks as measured by the Mayo-Portland Adaptability Inventory. Results support that IQ and some of the executive function measures (Processing Speed, Working Memory, and Trail-Making Test-Part B) correlated significantly and strongly and explained unique variance in all IADLs in this study. Data suggest that individuals with ABI who performed in the higher end of the low-average range or higher on measures of executive functioning tend to require little or no assistance to be independent with transportation, money management, living without support, and employment. Results also suggest that individuals with less executive dysfunction are likely to have greater overall community participation. PMID:23373638

Perna, Robert; Loughan, Ashlee R; Talka, Kristin

2012-01-01

267

Microglia processes block the spread of damage in the brain and require functional chloride channels.  

PubMed

Microglia cells exhibit two forms of motility, constant movement of filopodia probing surrounding brain tissue, and outgrowth of larger processes in response to nearby damage. The mechanisms and functions of filopodia sensing and process outgrowth are not well characterized but are likely critical for normal immune function in the brain. Using two photon laser scanning microscopy we investigated microglia process outgrowth in response to damage, and explored the relationship between process outgrowth and filopodia movement. Further, we examined the roles of Cl(-) or K(+) channel activation, as well as actin polymerization in these two distinct processes, because mechanistic understanding could provide a strategy to modulate microglia function. We found that volume sensitive Cl(-) channel blockers (NPPB, tamoxifen, DIDS) prevented the rapid process outgrowth of microglia observed in response to damage. In contrast, filopodia extension during sensing was resistant to Cl(-) channel inhibitors, indicating that these motile processes have different cellular mechanisms. However, both filopodia sensing and rapid process outgrowth were blocked by inhibition of actin polymerization. Following lesion formation under control conditions, rapidly outgrowing processes contacted the damaged area and this was associated with a 37% decrease in lesion volume. Inhibition of process outgrowth by Cl(-) channel block, prevention of actin polymerization, or by selectively ablating microglia all allowed lesion volume to increase and spread into the surrounding tissue. Therefore, process outgrowth in response to focal brain damage is beneficial by preventing lesion expansion and suggests microglia represent a front line defence against damage in the brain. PMID:19382211

Hines, Dustin J; Hines, Rochelle M; Mulligan, Sean J; Macvicar, Brian A

2009-11-15

268

Beta-amyloid, blood vessels and brain function  

PubMed Central

Cerebrovascular disease and Alzheimer’s disease are common diseases of aging and frequently co-exist in the same brain. Accumulating evidence suggests that the presence of brain infarction, including silent infarction, influences the course of Alzheimer’s disease. Conversely, there is evidence that beta-amyloid can impair blood vessel function. Vascular beta-amyloid deposition, also known as cerebral amyloid angiopathy, is associated with vascular dysfunction in animal and human studies. Alzheimer’s disease is associated with morphological changes in capillary networks, and soluble beta-amyloid produces abnormal vascular responses to physiologic and pharmacologic stimuli. In this review we discuss current evidence linking beta-amyloid metabolism with vascular function and morphological changes in animals and humans.

Smith, Eric E.; Greenberg, Steven M.

2009-01-01

269

Revealing Topological Organization of Human Brain Functional Networks with Resting-State Functional near Infrared Spectroscopy  

PubMed Central

Background The human brain is a highly complex system that can be represented as a structurally interconnected and functionally synchronized network, which assures both the segregation and integration of information processing. Recent studies have demonstrated that a variety of neuroimaging and neurophysiological techniques such as functional magnetic resonance imaging (MRI), diffusion MRI and electroencephalography/magnetoencephalography can be employed to explore the topological organization of human brain networks. However, little is known about whether functional near infrared spectroscopy (fNIRS), a relatively new optical imaging technology, can be used to map functional connectome of the human brain and reveal meaningful and reproducible topological characteristics. Results We utilized resting-state fNIRS (R-fNIRS) to investigate the topological organization of human brain functional networks in 15 healthy adults. Brain networks were constructed by thresholding the temporal correlation matrices of 46 channels and analyzed using graph-theory approaches. We found that the functional brain network derived from R-fNIRS data had efficient small-world properties, significant hierarchical modular structure and highly connected hubs. These results were highly reproducible both across participants and over time and were consistent with previous findings based on other functional imaging techniques. Conclusions Our results confirmed the feasibility and validity of using graph-theory approaches in conjunction with optical imaging techniques to explore the topological organization of human brain networks. These results may expand a methodological framework for utilizing fNIRS to study functional network changes that occur in association with development, aging and neurological and psychiatric disorders.

Zhao, Tengda; Shu, Ni; He, Yong

2012-01-01

270

Molecular Diversity of Glutamate Receptors and Implications for Brain Function  

Microsoft Academic Search

The glutamate receptors mediate excitatory neurotransmission in the brain and are important in memory acquisition, learning, and some neurodegenerative disorders. This receptor family is classified in three groups: the N-methyl-D-aspartate (NMDA), alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionate (AMPA)-kainate, and metabotropic receptors. Recent molecular studies have shown that many receptor subtypes exist in all three groups of the receptors and exhibit heterogeneity in function and expression

Shigetada Nakanishi

1992-01-01

271

Exploiting Temporal Information in Functional Magnetic Resonance Imaging Brain Data  

Microsoft Academic Search

Functional Magnetic Resonance Imaging(fMRI) has enabled scientists to look into the active human brain, leading to a flood of new data, thus encouraging the development of new data analysis methods. In this paper, we contribute a comprehensive framework for spatial and tem- poral exploration of fMRI data, and apply it to a challenging case study: separating drug addicted subjects from

Lei Zhang; Dimitris Samaras; Dardo Tomasi; Nelly Alia-klein; Lisa Cottone; Andreana Leskovjan; Nora D. Volkow; Rita Goldstein

2005-01-01

272

A systematic review of the evidence that brain structure is related to muscle structure and their relationship to brain and muscle function in humans over the lifecourse  

PubMed Central

Background An association between cognition and physical function has been shown to exist but the roles of muscle and brain structure in this relationship are not fully understood. A greater understanding of these relationships may lead to identification of the underlying mechanisms in this important area of research. This systematic review examines the evidence for whether: a) brain structure is related to muscle structure; b) brain structure is related to muscle function; and c) brain function is related to muscle structure in healthy children and adults. Methods Medline, Embase, CINAHL and PsycINFO were searched on March 6th 2014. A grey literature search was performed using Google and Google Scholar. Hand searching through citations and references of relevant articles was also undertaken. Results 53 articles were included in the review; mean age of the subjects ranged from 8.8 to 85.5 years old. There is evidence of a positive association between both whole brain volume and white matter (WM) volume and muscle size. Total grey matter (GM) volume was not associated with muscle size but some areas of regional GM volume were associated with muscle size (right temporal pole and bilateral ventromedial prefrontal cortex). No evidence was found of a relationship between grip strength and whole brain volume however there was some evidence of a positive association with WM volume. Conversely, there is evidence that gait speed is positively associated with whole brain volume; this relationship may be driven by total WM volume or regional GM volumes, specifically the hippocampus. Markers of brain ageing, that is brain atrophy and greater accumulation of white matter hyperintensities (WMH), were associated with grip strength and gait speed. The location of WMH is important for gait speed; periventricular hyperintensities and brainstem WMH are associated with gait speed but subcortical WMH play less of a role. Cognitive function does not appear to be associated with muscle size. Conclusion There is evidence that brain structure is associated with muscle structure and function. Future studies need to follow these interactions longitudinally to understand potential causal relationships.

2014-01-01

273

Brain Oscillations and Functional Connectivity during Overt Language Production  

PubMed Central

In the present study we investigate the communication of different large scale brain sites during an overt language production task with state of the art methods for the estimation of EEG functional connectivity. Participants performed a semantic blocking task in which objects were named in semantically homogeneous blocks of trials consisting of members of a semantic category (e.g., all objects are tools) or in heterogeneous blocks, consisting of unrelated objects. The classic pattern of slower naming times in the homogeneous relative to heterogeneous blocks is assumed to reflect the duration of lexical selection. For the collected data in the homogeneous and heterogeneous conditions the imaginary part of coherency (ImC) was evaluated at different frequencies. The ImC is a measure for detecting the coupling of different brain sites acting on sensor level. Most importantly, the ImC is robust to the artifact of volume conduction. We analyzed the ImC at all pairs of 56 EEG channels across all frequencies. Contrasting the two experimental conditions we found pronounced differences in the theta band at 7?Hz and estimated the most dominant underlying brain sources via a minimum norm inverse solution based on the ImC. As a result of the source localization, we observed connectivity between occipito-temporal and frontal areas, which are well-known to play a major role in lexical-semantic language processes. Our findings demonstrate the feasibility of investigating interactive brain activity during overt language production.

Ewald, Arne; Aristei, Sabrina; Nolte, Guido; Rahman, Rasha Abdel

2012-01-01

274

Distribution and function of melanocortin receptors within the brain.  

PubMed

Biological responses to pro-opiomelanocortin (POMC)-derived peptides administered in the brain were documented in the 1950s but their molecular mechanisms of action only began to be resolved with the mapping of melanocortin receptor subtypes to specific brain regions in the 1990s. Out of the five melanocortin receptor subtypes, MC3R and MC4R are widely recognised as 'neural' melanocortin receptors. In situ hybridization anatomical mapping of these receptor subtypes to distinct hypothalamic nuclei first indicated their roles in energy homeostasis, roles that were later confirmed with the obese phenotypes exhibited by Mc3R and Mc4R knockout mice. It is perhaps less well known however, that all five melanocortin receptor subtypes have been detected in developing and/or adult brains of various species. This chapter provides a comprehensive summary of the detection and mapping of each melanocortin receptor subtype in mammalian, chicken and fish brains and relates the sites of expression to functions that are either known or proposed for each receptor subtype. PMID:21222258

Mountjoy, Kathleen G

2010-01-01

275

Using Proton Magnetic Resonance Imaging and Spectroscopy to Understand Brain "Activation"  

ERIC Educational Resources Information Center

Upon stimulation, areas of the brain associated with specific cognitive processing tasks may undergo observable physiological changes, and measures of such changes have been used to create brain maps for visualization of stimulated areas in task-related brain "activation" studies. These perturbations usually continue throughout the period of the…

Baslow, Morris H.; Guilfoyle, David N.

2007-01-01

276

Epilepsy research: a window onto function and dysfunction of the human brain  

PubMed Central

As one of the most common neurological disorders, epilepsy has devastating behavioral, social, and occupational consequences and is associated with accumulating brain damage and neurological deficits. Epilepsy comprises a large number of syndromes, which vary greatly respect to their etiology and clinical features, but share the characteristic clinical hallmark of epilepsy recurrent spontaneous seizures. Research aimed at understanding the genetic, molecular, and cellular basis of epilepsy has to integrate various research approaches and techniques ranging from clinical expertise, functional analyses of the system and cellular levels, both in human subjects and rodent models of epilepsy, to human and mouse genetics. This knowledge may then be developed into novel treatment options with better control of seizures andlor fewer side effects. In addition, the study of epilepsy has frequently shed light on basic mechanisms underlying the function and dysfunction of the human brain.

Beck, Heinz; Elger, Christian E.

2008-01-01

277

Changes in regional brain perfusion during functional brain activation: comparison of [(64)Cu]-PTSM with [(14)C]-Iodoantipyrine.  

PubMed

A dilemma in behavioral brain mapping is that conventional techniques immobilize the subject, extinguishing all but the simplest behaviors. This is avoided if brain activation is imaged after completion of the behavior and tissue capture of the tracer. A single-pass flow tracer proposed for positron emission tomography (PET) is a radiolabeled copper(II) complex of pyruvaldehyde bis(N(4)-methylthiosemicarbazone), [Cu(64)]-PTSM. [Cu(64)]-PTSM reaches steady-state cerebral distribution more rapidly than the metabolic tracer [(18)F]-fluorodeoxyglucose, allowing imaging with substantially greater temporal resolution. Using dual-label autoradiography, this study compares the relative regional cerebral blood flow tracer distribution (CBF-TR) of [(64)Cu]-PTSM to that of the classic perfusion tracer [(14)C]-iodoantipyrine in a rat model during treadmill walking. Rats were exposed to continuous walking on a treadmill and compared to quiescent controls. [(64)Cu]-PTSM was bolus injected (iv) after 1 min, followed by a 5-minute uptake and subsequent bolus injection of [(14)C]-iodoantipyrine. CBF-TR was quantified by autoradiography and analyzed in the three-dimensionally reconstructed brain by statistical parametric mapping, as well as by region-of-interest analysis. A high homology was found between the [(64)Cu]-PTSM and [(14)C]-iodoantipyrine patterns of cerebral activation in cortical and subcortical regions. For white matter, however, [(64)Cu]-PTSM showed lower perfusion than [(14)Cu]-iodoantipyrine. [(64)Cu]-PTSM is a useful tracer for functional brain mapping in freely-moving subjects. Its application in conjunction with PET promises to increase our understanding of the neural circuitry of behaviors dependent on locomotion. PMID:18687316

Holschneider, D P; Yang, J; Sadler, T R; Galifianakis, N B; Bozorgzadeh, M H; Bading, J R; Conti, P S; Maarek, J-M I

2008-10-01

278

Functional magnetic resonance imaging reflects changes in brain functioning with sedation.  

PubMed

Functional magnetic resonance imaging (fMRI) studies have demonstrated localized brain activation during cognitive tasks. Brain activation increases with task complexity and decreases with familiarity. This study investigates how sleepiness alters the relationship between brain activation and task familiarity. We hypothesize that sleepiness prevents the reduction in activation associated with practice. Twenty-nine individuals rated their sleepiness using the Stanford Sleepiness Scale before fMRI. During imaging, subjects performed the Paced Auditory Serial Addition Test, a continuous mental arithmetic task. A positive correlation was observed between self-rated sleepiness and frontal brain activation. Fourteen subjects participated in phase 2. Sleepiness was induced by evening dosing with chlorpheniramine (CP) (8 mg or 12 mg) and terfenadine (60 mg) in the morning for 3 days before the second fMRI scan. The Multiple Sleep Latency Test (MSLT) was also performed. Results revealed a significant increase in fMRI activation in proportion to the dose of CP. In contrast, for all subjects receiving placebo there was a reduction in brain activation. MSLT revealed significant daytime sleepiness for subjects receiving CP. These findings suggest that sleepiness interferes with efficiency of brain functioning. The sleepy or sedated brain shows increased oxygen utilization during performance of a familiar cognitive task. Thus, the beneficial effect of prior task exposure is lost under conditions of sedation. Copyright 2000 John Wiley & Sons, Ltd. PMID:12404614

Starbuck, Victoria N; Kay, Gary G; Platenberg, R. Craig; Lin, Chin-Shoou; Zielinski, Brandon A

2000-12-01

279

Altered functional brain networks in Prader-Willi syndrome  

PubMed Central

Prader–Willi syndrome (PWS) is a genetic imprinting disorder characterized mainly by hyperphagia and early childhood obesity. Previous functional neuroimaging studies used visual stimuli to examine abnormal activities in the eating-related neural circuitry of patients with PWS. It was found that patients with PWS exhibited both excessive hunger and hyperphagia consistently, even in situations without any food stimulation. In the present study, we employed resting-state functional MRI techniques to investigate abnormal brain networks related to eating disorders in children with PWS. First, we applied amplitude of low-frequency fluctuation analysis to define the regions of interest that showed significant alterations in resting-state brain activity levels in patients compared with their sibling control group. We then applied a functional connectivity (FC) analysis to these regions of interest in order to characterize interactions among the brain regions. Our results demonstrated that patients with PWS showed decreased FC strength in the medial prefrontal cortex (MPFC)/inferior parietal lobe (IPL), MPFC/precuneus, IPL/precuneus and IPL/hippocampus in the default mode network; decreased FC strength in the pre-/postcentral gyri and dorsolateral prefrontal cortex (DLPFC)/orbitofrontal cortex (OFC) in the motor sensory network and prefrontal cortex network, respectively; and increased FC strength in the anterior cingulate cortex/insula, ventrolateral prefrontal cortex (VLPFC)/OFC and DLPFC/VLPFC in the core network and prefrontal cortex network, respectively. These findings indicate that there are FC alterations among the brain regions implicated in eating as well as rewarding, even during the resting state, which may provide further evidence supporting the use of PWS as a model to study obesity and to provide information on potential neural targets for the medical treatment of overeating.

Zhang, Yi; Zhao, Heng; Qiu, Siyou; Tian, Jie; Wen, Xiaotong; Miller, Jennifer L.; von Deneen, Karen M.; Zhou, Zhenyu; Gold, Mark S.; Liu, Yijun

2013-01-01

280

Multifaceted genomic risk for brain function in schizophrenia.  

PubMed

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 toward 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

2012-07-16

281

[The effect of Piracetam on adolescent brain function].  

PubMed

A report on investigations with Piracetam, recently introduced into therapy, is given. Piracetam is mainly characterized by cerebral metabolic effects, leading to an activation of cerebral functions as well as to brain protection. Experimental studies showed the highly selective activity of Piracetam on cerebral cortex, which is responsible for higher mental functions as consciousness, vigilance and memory. Therapeutic results in 48 adolescents with poor school results are reported. These patients were treated with Piracetam for a continuous period up to 14 months. The therapy lead to convincing improvements in terms of school results. PMID:1213644

Fiegel, G

1975-09-11

282

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

283

Synchronization-based approach for detecting functional activation of brain  

NASA Astrophysics Data System (ADS)

In this paper, we investigate a synchronization-based, data-driven clustering approach for the analysis of functional magnetic resonance imaging (fMRI) data, and specifically for detecting functional activation from fMRI data. We first define a new measure of similarity between all pairs of data points (i.e., time series of voxels) integrating both complete phase synchronization and amplitude correlation. These pairwise similarities are taken as the coupling between a set of Kuramoto oscillators, which in turn evolve according to a nearest-neighbor rule. As the network evolves, similar data points naturally synchronize with each other, and distinct clusters will emerge. The clustering behavior of the interaction network of the coupled oscillators, therefore, mirrors the clustering property of the original multiple time series. The clustered regions whose cross-correlation coefficients are much greater than other regions are considered as the functionally activated brain regions. The analysis of fMRI data in auditory and visual areas shows that the recognized brain functional activations are in complete correspondence with those from the general linear model of statistical parametric mapping, but with a significantly lower time complexity. We further compare our results with those from traditional K-means approach, and find that our new clustering approach can distinguish between different response patterns more accurately and efficiently than the K-means approach, and therefore more suitable in detecting functional activation from event-related experimental fMRI data.

Hong, Lei; Cai, Shi-Min; Zhang, Jie; Zhuo, Zhao; Fu, Zhong-Qian; Zhou, Pei-Ling

2012-09-01

284

Synchronization-based approach for detecting functional activation of brain.  

PubMed

In this paper, we investigate a synchronization-based, data-driven clustering approach for the analysis of functional magnetic resonance imaging (fMRI) data, and specifically for detecting functional activation from fMRI data. We first define a new measure of similarity between all pairs of data points (i.e., time series of voxels) integrating both complete phase synchronization and amplitude correlation. These pairwise similarities are taken as the coupling between a set of Kuramoto oscillators, which in turn evolve according to a nearest-neighbor rule. As the network evolves, similar data points naturally synchronize with each other, and distinct clusters will emerge. The clustering behavior of the interaction network of the coupled oscillators, therefore, mirrors the clustering property of the original multiple time series. The clustered regions whose cross-correlation coefficients are much greater than other regions are considered as the functionally activated brain regions. The analysis of fMRI data in auditory and visual areas shows that the recognized brain functional activations are in complete correspondence with those from the general linear model of statistical parametric mapping, but with a significantly lower time complexity. We further compare our results with those from traditional K-means approach, and find that our new clustering approach can distinguish between different response patterns more accurately and efficiently than the K-means approach, and therefore more suitable in detecting functional activation from event-related experimental fMRI data. PMID:23020467

Hong, Lei; Cai, Shi-Min; Zhang, Jie; Zhuo, Zhao; Fu, Zhong-Qian; Zhou, Pei-Ling

2012-09-01

285

Heritability of human brain functioning as assessed by electroencephalography.  

PubMed Central

To study the genetic and environmental contributions to individual differences in CNS functioning, the electroencephalogram (EEG) was measured in 213 twin pairs age 16 years. EEG was measured in 91 MZ and 122 DZ twins. To quantify sex differences in the genetic architecture, EEG was measured in female and male same-sex twins and in opposite-sex twins. EEG was recorded on 14 scalp positions during quiet resting with eyes closed. Spectral powers were calculated for four frequency bands: delta, theta, alpha, and beta. Twin correlations pointed toward high genetic influences for all these powers and scalp locations. Model fitting confirmed these findings; the largest part of the variance of the EEG is explained by additive genetic factors. The averaged heritabilites for the delta, theta, alpha and beta frequencies was 76%, 89%, 89%, and 86%, respectively. Multivariate analyses suggested that the same genes for EEG alpha rhythm were expressed in different brain areas in the left and right hemisphere. This study shows that brain functioning, as indexed by rhythmic brain-electrical activity, is one of the most heritable characteristics in humans.

van Beijsterveldt, C. E.; Molenaar, P. C.; de Geus, E. J.; Boomsma, D. I.

1996-01-01

286

Roles of Brain Angiotensin II in Cognitive Function and Dementia  

PubMed Central

The brain renin-angiotensin system (RAS) has been highlighted as having a pathological role in stroke, dementia, and neurodegenerative disease. Particularly, in dementia, epidemiological studies indicate a preventive effect of RAS blockade on cognitive impairment in Alzheimer disease (AD). Moreover, basic experiments suggest a role of brain angiotensin II in neural injury, neuroinflammation, and cognitive function and that RAS blockade attenuates cognitive impairment in rodent dementia models of AD. Therefore, RAS regulation is expected to have therapeutic potential for AD. Here, we discuss the role of angiotensin II in cognitive impairment and AD. Angiotensin II binds to the type 2 receptor (AT2) and works mainly by binding with the type 1 receptor (AT1). AT2 receptor signaling plays a role in protection against multiple-organ damage. A direct AT2 receptor agonist is now available and is expected to reduce inflammation and oxidative stress and enhance cell differentiation. We and other groups reported that AT2 receptor activation enhances neuronal differentiation and neurite outgrowth in the brain. Here, we also review the effect of the AT2 receptor on cognitive function. RAS modulation may be a new therapeutic option for dementia including AD in the future.

Mogi, Masaki; Iwanami, Jun; Horiuchi, Masatsugu

2012-01-01

287

Lateralization of Cognitive Functions in Aphasia after Right Brain Damage  

PubMed Central

Purpose The lateralization of cognitive functions in crossed aphasia in dextrals (CAD) has been explored and compared mainly with cases of aphasia with left hemisphere damage. However, comparing the neuropsychological aspects of CAD and aphasia after right brain damage in left-handers (ARL) could potentially provide more insights into the effect of a shift in the laterality of handedness or language on other cognitive organization. Thus, this case study compared two cases of CAD and one case of ARL. Materials and Methods The following neuropsychological measures were obtained from three aphasic patients with right brain damage (two cases of CAD and one case of ARL); language, oral and limb praxis, and nonverbal cognitive functions (visuospatial neglect and visuospatial construction). Results All three patients showed impaired visuoconstructional abilities, whereas each patient showed a different level of performances for oral and limb praxis, and visuospatial neglect. Conclusion Based on the analysis of these three aphasic patients' performances, we highlighted the lateralization of language, handedness, oral and limb praxis, visuospatial neglect and visuospatial constructive ability in aphasic patients with right brain damage.

Ha, Ji-Wan; Hwang, Yu Mi; Sim, Hyunsub

2012-01-01

288

Reorganization of Functional Connectivity as a Correlate of Cognitive Recovery in Acquired Brain Injury  

ERIC Educational Resources Information Center

Cognitive processes require a functional interaction between specialized multiple, local and remote brain regions. Although these interactions can be strongly altered by an acquired brain injury, brain plasticity allows network reorganization to be principally responsible for recovery. The present work evaluates the impact of brain injury on…

Castellanos, Nazareth P.; Paul, Nuria; Ordonez, Victoria E.; Demuynck, Olivier; Bajo, Ricardo; Campo, Pablo; Bilbao, Alvaro; Ortiz, Tomas; del-Pozo, Francisco; Maestu, Fernando

2010-01-01

289

CD36 expression and brain function: does CD36 deficiency impact learning ability?  

Microsoft Academic Search

This article first presents an overview of published literature documenting the role of the scavenger receptor CD36 in activation of brain microglia with reference to brain pathologies such as Alzheimer's and malaria. Second, the possibility that CD36 may play a role in brain FA metabolism is discussed. Long-chain polyunsaturated fatty acids (PUFAs) are important for brain function and are mostly

Nada A. Abumrad; Mohammad Ajmal; Kostas Pothakos; John K. Robinson

2005-01-01

290

Jung's understanding of schizophrenia: is it still relevant in the 'era of the brain'?  

PubMed

Jung was highly committed to grasping the meaning of psychotic thinking, and left behind precious insights to treatment scattered through his works written between 1906 and 1958. The tendency of today's psychiatry is to attribute the psychotic process to alteration in the brain's anatomy, biochemistry and electrophysiology, thus exempting the subject, i.e. the afflicted person, from responsibility for attachment to reality and their sanity. Jung understood schizophrenia as an 'abaissement du niveau mental', a similar phenomenon to the one encountered in dreams, and caused by a peculiar 'faiblesse de la volonté'. He contested that complexes in schizophrenia, in contrast with neurotic disorders, are disconnected and can either never reintegrate to the psychic totality or can only join together in remission 'like a mirror broke into splinters' (Jung , para. 507). Accordingly, a person who does not fight for the supremacy of ego consciousness and has let themself be swayed by the intrusion of alien contents arising from the unconscious (even to the point of becoming fascinated by regression) is exposed to the danger of schizophrenia. The contemporary relevance of these notions and their necessity in understanding the psychotic process in the light of modern scientific findings are discussed. PMID:24673276

Abramovitch, Yehuda

2014-04-01

291

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.

Colver, Allan; Longwell, Sarah

2014-01-01

292

Integrating functional brain neuroimaging and developmental cognitive neuroscience in child psychiatry research  

PubMed Central

Objective To provide an overview of clinical research aiming to develop a mechanistic understanding of brain dysfunction in child psychiatric disorders. Method Technological, conceptual and translational approaches relevant to the investigation of brain function in pediatric psychiatric illnesses are explored. Research in the area of pediatric bipolar disorder is used as a prototypic model illustrating the use of complementary techniques of functional magnetic neuroimaging and neurocognitive studies to identify abnormalities in neural circuitry function. Results Studies of bipolar youth indicate impairment in cognitive and affective neural systems and in the interface of these two circuits. This evolving field paves a future pathway for identifying diagnostic biomarkers for the disorder, providing tools for monitoring response to pharmacotherapy, examining illness-associated alterations in developmental trajectory, and facilitating the use of animal research for guiding the development of novel treatment strategies. Conclusion Studies of brain function in child psychiatry are establishing a platform of knowledge and methods that offer promise for revolutionizing both models of illness pathophysiology as well as future diagnostic and therapeutic practice.

Pavuluri, Mani N; Sweeney, John A

2009-01-01

293

Strengthened functional connectivity in the brain during muscle fatigue.  

PubMed

Fatigue caused by sustaining submaximal-intensity muscle contraction(s) involves increased activation in the brain such as primary motor cortex (M1), primary sensory cortex (S1), premotor and supplementary motor area (PM&SMA) and prefrontal cortex (PFC). The synchronized increases in activation level in these cortical areas suggest fatigue-related strengthening of functional coupling within the motor control network. In the present study, this hypothesis was tested using the cross-correlation based functional connectivity (FC) analysis method. Ten subjects performed a 20-minute intermittent (3.5s ON/6.5s OFF, 120 trials total) handgrip task using the right hand at 50% maximal voluntary contraction (MVC) force level while their brain was scanned by a 3 T Siemens Trio scanner using echo planar imaging (EPI) sequence. A representative signal time course of the left M1 was extracted by averaging the time course data of a 2-mm cluster of neighboring voxels of local maximal activation foci, which was identified by a general linear model. Two FC activation maps were created for each subject by cross-correlating the time course data of the minimal (the first 10 trials) and significant (the last 10 trials) fatigue stages across all the voxels in the brain to the corresponding representative time course. Histogram and quantile regression analysis were used to compare the FC between the minimal and significant fatigue stages and the results showed a significant increase in FC among multiple cortical regions, including right M1 and bilateral PM&SMA, S1 and PFC. This strengthened FC indicates that when muscle fatigue worsens, many brain regions increase their coupling with the left M1, the primary motor output control center for the right handgrip, to compensate for diminished force generating capability of the muscle in a coordinated fashion by enhancing the descending command for greater muscle recruitment to maintain the same force. PMID:22197785

Jiang, Zhiguo; Wang, Xiao-Feng; Kisiel-Sajewicz, Katarzyna; Yan, Jin H; Yue, Guang H

2012-03-01

294

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. Hum Brain Mapp 35:4620-4634, 2014. © 2014 Wiley Periodicals, Inc. PMID:24639411

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

2014-09-01

295

Neurophysiological architecture of functional magnetic resonance images of human brain.  

PubMed

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 functional connections, defined by the group mean inter-regional partial correlation matrix, were mostly either local and intrahemispheric or symmetrically interhemispheric. Low-frequency components in the time series subtended stronger inter-regional correlations than high-frequency components. Intrahemispheric connectivity was generally related to anatomical distance by an inverse square law; many symmetrical interhemispheric connections were stronger than predicted by the anatomical distance between bilaterally homologous regions. Strong interhemispheric connectivity was notably absent in data acquired from a single patient, minimally conscious following a brainstem lesion. Multivariate analysis by hierarchical clustering and multidimensional scaling consistently defined six major systems in healthy volunteers-- corresponding approximately to four neocortical lobes, medial temporal lobe and subcortical nuclei- - that could be further decomposed into anatomically and functionally plausible subsystems, e.g. dorsal and ventral divisions of occipital cortex. An undirected graph derived by thresholding the healthy group mean partial correlation matrix demonstrated local clustering or cliquishness of connectivity and short mean path length compatible with prior data on small world characteristics of non-human cortical anatomy. Functional MRI demonstrates a neurophysiological architecture of the normal human brain that is anatomically sensible, strongly symmetrical, disrupted by acute brain injury, subtended predominantly by low frequencies and consistent with a small world network topology. PMID:15635061

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

2005-09-01

296

Detecting brain state changes via fiber-centered functional connectivity analysis.  

PubMed

Diffusion tensor imaging (DTI) and functional magnetic resonance imaging (fMRI) have been widely used to study structural and functional brain connectivity in recent years. A common assumption used in many previous functional brain connectivity studies is the temporal stationarity. However, accumulating literature evidence has suggested that functional brain connectivity is under temporal dynamic changes in different time scales. In this paper, a novel and intuitive approach is proposed to model and detect dynamic changes of functional brain states based on multimodal fMRI/DTI data. The basic idea is that functional connectivity patterns of all fiber-connected cortical voxels are concatenated into a descriptive functional feature vector to represent the brain's state, and the temporal change points of brain states are decided by detecting the abrupt changes of the functional vector patterns via the sliding window approach. Our extensive experimental results have shown that meaningful brain state change points can be detected in task-based fMRI/DTI, resting state fMRI/DTI, and natural stimulus fMRI/DTI data sets. Particularly, the detected change points of functional brain states in task-based fMRI corresponded well to the external stimulus paradigm administered to the participating subjects, thus partially validating the proposed brain state change detection approach. The work in this paper provides novel perspective on the dynamic behaviors of functional brain connectivity and offers a starting point for future elucidation of the complex patterns of functional brain interactions and dynamics. PMID:22941508

Li, Xiang; Lim, Chulwoo; Li, Kaiming; Guo, Lei; Liu, Tianming

2013-04-01

297

Using computational models to relate structural and functional brain connectivity  

PubMed Central

Modern imaging methods allow a non-invasive assessment of both structural and functional brain connectivity. This has lead to the identification of disease-related alterations affecting functional connectivity. The mechanism of how such alterations in functional connectivity arise in a structured network of interacting neural populations is as yet poorly understood. Here we use a modeling approach to explore the way in which this can arise and to highlight the important role that local population dynamics can have in shaping emergent spatial functional connectivity patterns. The local dynamics for a neural population is taken to be of the Wilson–Cowan type, whilst the structural connectivity patterns used, describing long-range anatomical connections, cover both realistic scenarios (from the CoComac database) and idealized ones that allow for more detailed theoretical study. We have calculated graph–theoretic measures of functional network topology from numerical simulations of model networks. The effect of the form of local dynamics on the observed network state is quantified by examining the correlation between structural and functional connectivity. We document a profound and systematic dependence of the simulated functional connectivity patterns on the parameters controlling the dynamics. Importantly, we show that a weakly coupled oscillator theory explaining these correlations and their variation across parameter space can be developed. This theoretical development provides a novel way to characterize the mechanisms for the breakdown of functional connectivity in diseases through changes in local dynamics.

Hlinka, Jaroslav; Coombes, Stephen

2012-01-01

298

One Decade Later: What has Gene Expression Profiling Told us About Neuronal Cell Types, Brain Function and Disease?  

PubMed Central

The many diverse functions executed by the central nervous system (CNS) are mirrored in the diverse shapes, connections, and firing patterns of its individual neuronal cell types. Furthermore, distinct neurological diseases are the result of defects in specific neuronal cell types. However, despite the significance of this cellular diversity underlying brain function and disease, we know relatively little about the genes that contribute to purposeful differences among regions and cell types within the brain. A major challenge in this endeavor is the paucity of markers that define the many regions and cell types thought to exist. Cataloging the neuronal cell types and cell- and region-specific marker genes requires novel avenues that enable researchers to define gene expression profiles of brain regions and individual neurons and to apply this information to understand functional and structural properties in the normal and diseased brain. Functional genomic approaches such as gene expression profiling offers the exclusive opportunity to glimpse the detailed inner workings of distinct neuronal cell types. Recent studies have applied microarray technology in unique and novel ways to understand the molecular mechanisms that underlie such neuronal diversity and their potential role in brain diseases.

Diaz, Elva

2009-01-01

299

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

PubMed

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

300

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

301

Estimation of premorbid functioning after traumatic brain injury.  

PubMed

Estimation of premorbid functioning in patients with traumatic brain injury (TBI) is a difficult but necessary step both in the assessment of neurological impairment and in planning treatment. Because the estimation process is almost always retrospective, its reliability is questionable. The use of multiple sources of information improves the likelihood of an accurate estimate. The effects of TBI cross a number of domains in the victim's life. Thus, premorbid functioning must be estimated in the physical, cognitive, emotional, social, financial and vocational spheres. Knowledge of baseline or premorbid functioning levels allows the clinician to appreciate the severity of injury, provide a prognosis, and shape treatment goals that are specific to the individual. In this article, we present the key questions to be addressed, suggest sources of information to obtain the answers, describe the processes through which answers should be obtained, and outline the uses for this important information in working with victims of TBI. PMID:24525805

Ruff, R M; Mueller, J; Jurica, P

1996-01-01

302

Informing brain connectivity with optogenetic functional magnetic resonance imaging.  

PubMed

Optogenetic functional magnetic resonance imaging (ofMRI) is a novel approach that combines optogenetic control of neural circuits with high-field functional MRI. Optogenetics is a neuro-modulation technology in which light-activated trans-membrane conductance regulators are introduced into specifically targeted cell types to allow temporally precise, millisecond-scale activity modulation in vivo. By combining optogenetic control with fMRI readout, neural activity arising from specific circuit elements defined by genetic identity, cell body location, and axonal projection targets can be monitored in vivo across the whole brain. These unique features of ofMRI open new vistas for in vivo characterization of the dense plexus of neural connections according to their type and functionality. PMID:22326987

Lee, Jin Hyung

2012-10-01

303

Longitudinal assessment of default-mode brain function in aging.  

PubMed

Age-related changes in the default-mode network (DMN) have been identified in prior cross-sectional functional magnetic resonance imaging studies. Here, we investigated longitudinal change in DMN activity and connectivity. Cognitively intact participants (aged 49-79 years at baseline) were scanned twice, with a 6-year interval, while performing an episodic memory task interleaved with a passive control condition. Longitudinal analyses showed that the DMN (control condition > memory task) could be reliably identified at both baseline and follow-up. Differences in the magnitude of task-induced deactivation in posterior DMN regions were observed between baseline and follow-up indicating reduced deactivation in these regions with increasing age. Although no overall longitudinal changes in within-network connectivity were found across the whole sample, individual differences in memory change correlated with change in connectivity. Thus, our results show stability of whole-brain DMN topology and functional connectivity over time in healthy older adults, whereas within-region DMN analyses show reduced deactivation between baseline and follow-up. The current findings provide novel insights into DMN functioning that may assist in identifying brain changes in patient populations, as well as characterizing factors that distinguish between normal and pathologic aging. PMID:24767950

Persson, Jonas; Pudas, Sara; Nilsson, Lars-Göran; Nyberg, Lars

2014-09-01

304

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.

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

305

Brain Structure and Executive Functions in Children with Cerebral Palsy: A Systematic Review  

ERIC Educational Resources Information Center

This systematic review aimed to establish the current knowledge about brain structure and executive function (EF) in children with cerebral palsy (CP). Five databases were searched (up till July 2012). Six articles met the inclusion criteria, all included structural brain imaging though no functional brain imaging. Study quality was assessed using…

Weierink, Lonneke; Vermeulen, R. Jeroen; Boyd, Roslyn N.

2013-01-01

306

Correlation between structural and functional changes in brain in an idiopathic headache syndrome  

Microsoft Academic Search

Fundamental to the concept of idiopathic or primary headache, including migraine, tension-type headache and cluster headache, is the currently accepted view that these conditions are due to abnormal brain function with completely normal brain structure. Cluster headache is one such idiopathic headache with many similarities to migraine, including normal brain structure on magnetic resonance imaging and abnormal function in the

A. May; J. Ashburner; C. Büchel; D. J. McGonigle; K. J. Friston; R. S. J. Frackowiak; P. J. Goadsby

1999-01-01

307

Some Problems for Representations of Brain Organization Based on Activation in Functional Imaging  

ERIC Educational Resources Information Center

Functional brain imaging has overshadowed traditional lesion studies in becoming the dominant approach to the study of brain-behavior relationships. The proponents of functional imaging studies frequently argue that this approach provides an advantage over lesion studies by observing normal brain activity in vivo without the disruptive effects of…

Sidtis, John J.

2007-01-01

308

Preinjury emotional and family functioning in caregivers of persons with traumatic brain injury  

Microsoft Academic Search

Sander AM, Sherer M, Malec JF, High WM Jr, Thompson RN, Moessner AM, Josey J. Preinjury emotional and family functioning in caregivers of persons with traumatic brain injury. 2003;84:197-203. Objective: To characterize the preinjury family functioning, emotional distress, and social support of caregivers of persons with traumatic brain injury (TBI). Design: Inception cohort. Setting: Three Traumatic Brain Injury Model Systems

Angelle M. Sander; Mark Sherer; James F. Malec; Walter M. High; Risa Nakase Thompson; Anne M. Moessner; Jennifer Josey

2003-01-01

309

Alcohol: Effects on Neurobehavioral Functions and the Brain  

PubMed Central

Alcoholism results from an interplay between genetic and environmental factors, and is linked to brain defects and associated cognitive, emotional, and behavioral impairments. A confluence of findings from neuroimaging, physiological, neuropathological, and neuropsychological studies of alcoholics indicate that the frontal lobes, limbic system, and cerebellum are particularly vulnerable to damage and dysfunction. An integrative approach employing a variety of neuroscientific technologies is essential for recognizing the interconnectivity of the different functional systems affected by alcoholism. In that way, relevant experimental techniques can be applied to assist in determining the degree to which abstinence and treatment contribute to the reversal of atrophy and dysfunction.

Oscar-Berman, Marlene; Marinkovic, Ksenija

2014-01-01

310

Congenital platelet disorders and understanding of platelet function.  

PubMed

Genetic defects of platelets constitute rare diseases that include bleeding syndromes of autosomal dominant, recessive or X-linked inheritance. They affect platelet production, resulting in a low circulating platelet count and changes in platelet morphology, platelet function, or a combination of both with altered megakaryopoiesis and a defective platelet response. As a result, blood platelets fail to fulfil their haemostatic function. Most studied of the platelet function disorders are deficiencies of glycoprotein mediators of adhesion and aggregation while defects of primary receptors for stimuli include the P2Y12 ADP receptor. Studies on inherited defects of (i) secretion from storage organelles (dense granules, ?-granules), (ii) the platelet cytoskeleton and (iii) the generation of pro-coagulant activity have identified genes indirectly controlling the functional response. Signalling pathway defects leading to agonist-specific modifications of platelet aggregation are the current target of exome-sequencing strategies. We now review recent advances in the molecular characterization of platelet function defects. PMID:24286193

Nurden, Alan T; Nurden, Paquita

2014-04-01

311

Disrupted functional brain connectivity and its association to structural connectivity in amnestic mild cognitive impairment and Alzheimer's disease.  

PubMed

Although anomalies in the topological architecture of whole-brain connectivity have been found to be associated with Alzheimer's disease (AD), our understanding about the progression of AD in a functional connectivity (FC) perspective is still rudimentary and few study has explored the function-structure relations in brain networks of AD patients. By using resting-state functional MRI (fMRI), this study firstly investigated organizational alternations in FC networks in 12 AD patients, 15 amnestic mild cognitive impairment (aMCI) patients, and 14 age-matched healthy aging subjects and found that all three groups exhibit economical small-world network properties. Nonetheless, we found a decline of the optimal architecture in the progression of AD, represented by a more localized modular organization with less efficient local information transfer. Our results also show that aMCI forms a boundary between normal aging and AD and represents a functional continuum between healthy aging and the earliest signs of dementia. Moreover, we revealed a dissociated relationship between the overall FC and structural connectivity (SC) in AD patients. In this study, diffusion tensor imaging tractography was used to map the structural network of the same individuals. The decreased FC-SC coupling may be indicative of more stringent and less dynamic brain function in AD patients. Our findings provided insightful implications for understanding the pathophysiological mechanisms of brain dysfunctions in aMCI and AD patients and demonstrated that functional disorders can be characterized by multimodal neuroimaging-based metrics. PMID:24806295

Sun, Yu; Yin, Qihua; Fang, Rong; Yan, Xiaoxiao; Wang, Ying; Bezerianos, Anastasios; Tang, Huidong; Miao, Fei; Sun, Junfeng

2014-01-01

312

Disrupted Functional Brain Connectivity and Its Association to Structural Connectivity in Amnestic Mild Cognitive Impairment and Alzheimer's Disease  

PubMed Central

Although anomalies in the topological architecture of whole-brain connectivity have been found to be associated with Alzheimer’s disease (AD), our understanding about the progression of AD in a functional connectivity (FC) perspective is still rudimentary and few study has explored the function-structure relations in brain networks of AD patients. By using resting-state functional MRI (fMRI), this study firstly investigated organizational alternations in FC networks in 12 AD patients, 15 amnestic mild cognitive impairment (aMCI) patients, and 14 age-matched healthy aging subjects and found that all three groups exhibit economical small-world network properties. Nonetheless, we found a decline of the optimal architecture in the progression of AD, represented by a more localized modular organization with less efficient local information transfer. Our results also show that aMCI forms a boundary between normal aging and AD and represents a functional continuum between healthy aging and the earliest signs of dementia. Moreover, we revealed a dissociated relationship between the overall FC and structural connectivity (SC) in AD patients. In this study, diffusion tensor imaging tractography was used to map the structural network of the same individuals. The decreased FC-SC coupling may be indicative of more stringent and less dynamic brain function in AD patients. Our findings provided insightful implications for understanding the pathophysiological mechanisms of brain dysfunctions in aMCI and AD patients and demonstrated that functional disorders can be characterized by multimodal neuroimaging-based metrics.

Yan, Xiaoxiao; Wang, Ying; Bezerianos, Anastasios; Tang, Huidong; Miao, Fei; Sun, Junfeng

2014-01-01

313

EEG Combined with MEG and TMS in Studies of Human Brain Function.  

National Technical Information Service (NTIS)

This thesis deals with the recording of the brain's electrophysiological responses either to sensory stimuli or to direct magnetic stimulation of the cortex. In order to develop novel tools for experimental brain research, two combinations of functional b...

J. Virtanen

1998-01-01

314

Structural and functional brain connectivity in presymptomatic familial frontotemporal dementia  

PubMed Central

Objective: We aimed to investigate whether cognitive deficits and structural and functional connectivity changes can be detected before symptom onset in a large cohort of carriers of microtubule-associated protein tau and progranulin mutations. Methods: In this case-control study, 75 healthy individuals (aged 20–70 years) with 50% risk for frontotemporal dementia (FTD) underwent DNA screening, neuropsychological assessment, and structural and functional MRI. We used voxel-based morphometry and tract-based spatial statistics for voxelwise analyses of gray matter volume and diffusion tensor imaging measures. Using resting-state fMRI scans, we assessed whole-brain functional connectivity to frontoinsula, anterior midcingulate cortex (aMCC), and posterior cingulate cortex. Results: Although carriers (n = 37) and noncarriers (n = 38) had similar neuropsychological performance, worse performance on Stroop III, Ekman faces, and Happé cartoons correlated with higher age in carriers, but not controls. Reduced fractional anisotropy and increased radial diffusivity throughout frontotemporal white matter tracts were found in carriers and correlated with higher age. Reductions in functional aMCC connectivity were found in carriers compared with controls, and connectivity between frontoinsula and aMCC seeds and several brain regions significantly decreased with higher age in carriers but not controls. We found no significant differences or age correlations in posterior cingulate cortex connectivity. No differences in regional gray matter volume were found. Conclusions: This study convincingly demonstrates that alterations in structural and functional connectivity develop before the first symptoms of FTD arise. These findings suggest that diffusion tensor imaging and resting-state fMRI may have the potential to become sensitive biomarkers for early FTD in future clinical trials.

Dopper, Elise G.P.; Rombouts, Serge A.R.B.; Jiskoot, Lize C.; den Heijer, Tom; de Graaf, J. Roos A.; de Koning, Inge; Hammerschlag, Anke R.; Seelaar, Harro; Seeley, William W.; Veer, Ilya M.; van Buchem, Mark A.; Rizzu, Patrizia

2013-01-01

315

Understanding Complex Natural Systems by Articulating Structure-Behavior-Function Models  

ERIC Educational Resources Information Center

Artificial intelligence research on creative design has led to Structure-Behavior-Function (SBF) models that emphasize functions as abstractions for organizing understanding of physical systems. Empirical studies on understanding complex systems suggest that novice understanding is shallow, typically focusing on their visible structures and…

Vattam, Swaroop S.; Goel, Ashok K.; Rugaber, Spencer; Hmelo-Silver, Cindy E.; Jordan, Rebecca; Gray, Steven; Sinha, Suparna

2011-01-01

316

Problems in understanding the organization, structure and function of chromosomes.  

National Technical Information Service (NTIS)

Despite intensive investigation of mammalian chromosomes, we are still largely ignorant of the basic rules that govern their organization, structure, and functions. This situation results from the current limitations in available technologies to elucidate...

E. M. Bradbury

1990-01-01

317

Deciphering the functions and regulation of brain-enriched A-to-I RNA editing  

PubMed Central

Adenosine-to-inosine (A-to-I) RNA editing, in which genomically encoded adenosine is changed to inosine in RNA, is catalyzed by adenosine deaminase acting on RNA (ADAR). This fine-tuning mechanism is critical during normal development and diseases, particularly in relation to brain functions. A-to-I RNA editing has also been hypothesized to be a driving force in human brain evolution. A large number of RNA editing sites have recently been identified, mostly as a result of the development of deep sequencing and bioinformatic analyses. Deciphering the functional consequences of RNA editing events is challenging, but emerging genome engineering approaches may expedite new discoveries. To understand how RNA editing is dynamically regulated, it is imperative to construct a spatiotemporal atlas at the species, tissue and cell levels. Future studies will need to identify the cis and trans regulatory factors that drive the selectivity and frequency of RNA editing. We anticipate that recent technological advancements will aid researchers in acquiring a much deeper understanding of the functions and regulation of RNA editing.

Li, Jin Billy; Church, George M

2014-01-01

318

"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.

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

2009-01-01

319

Functional specializations for music processing in the human newborn brain  

PubMed Central

In adults, specific neural systems with right-hemispheric weighting are necessary to process pitch, melody, and harmony as well as structure and meaning emerging from musical sequences. It is not known to what extent the specialization of these systems results from long-term exposure to music or from neurobiological constraints. One way to address this question is to examine how these systems function at birth, when auditory experience is minimal. We used functional MRI to measure brain activity in 1- to 3-day-old newborns while they heard excerpts of Western tonal music and altered versions of the same excerpts. Altered versions either included changes of the tonal key or were permanently dissonant. Music evoked predominantly right-hemispheric activations in primary and higher order auditory cortex. During presentation of the altered excerpts, hemodynamic responses were significantly reduced in the rig1ht auditory cortex, and activations emerged in the left inferior frontal cortex and limbic structures. These results demonstrate that the infant brain shows a hemispheric specialization in processing music as early as the first postnatal hours. Results also indicate that the neural architecture underlying music processing in newborns is sensitive to changes in tonal key as well as to differences in consonance and dissonance.

Perani, Daniela; Saccuman, Maria Cristina; Scifo, Paola; Spada, Danilo; Andreolli, Guido; Rovelli, Rosanna; Baldoli, Cristina; Koelsch, Stefan

2010-01-01

320

Functional Brain Mapping in Freely Moving Rats During Treadmill Walking  

PubMed Central

Summary A dilemma in functional neuroimaging is that immobilization of the subject, necessary to avoid movement artifact, extinguishes all but the simplest behaviors. Recently, we developed an implantable microbolus infusion pump (MIP) that allows bolus injection of radiotracers by remote activation in freely moving, nontethered animals. The MIP is examined as a tool for brain mapping in rats during a locomotor task. Cerebral blood flow–related tissue radioactivity (CBF-TR) was measured using [14C]-iodoantipyrine with an indicator-fractionation method, followed by autoradiography. Rats exposed to walking on a treadmill, compared to quiescent controls, showed increases in CBF-TR in motor circuits (primary motor cortex, dorsolateral striatum, ventrolateral thalamus, midline cerebellum, copula pyramis, paramedian lobule), in primary somatosensory cortex mapping the forelimbs, hindlimbs and trunk, as well as in secondary visual cortex. These results support the use of implantable pumps as adjunct tools for functional neuroimaging of behaviors that cannot be elicited in restrained or tethered animals.

Holschneider, D. P.; Maarek, J.-M. I.; Yang, J.; Harimoto, J.; Scremin, O. U.

2014-01-01

321

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.

Linnman, C; Becerra, L; Borsook, D

2012-01-01

322

Long-Term Enhancement of Brain Function and Cognition Using Cognitive Training and Brain Stimulation  

PubMed Central

Summary Noninvasive brain stimulation has shown considerable promise for enhancing cognitive functions by the long-term manipulation of neuroplasticity [1–3]. However, the observation of such improvements has been focused at the behavioral level, and enhancements largely restricted to the performance of basic tasks. Here, we investigate whether transcranial random noise stimulation (TRNS) can improve learning and subsequent performance on complex arithmetic tasks. TRNS of the bilateral dorsolateral prefrontal cortex (DLPFC), a key area in arithmetic [4, 5], was uniquely coupled with near-infrared spectroscopy (NIRS) to measure online hemodynamic responses within the prefrontal cortex. Five consecutive days of TRNS-accompanied cognitive training enhanced the speed of both calculation- and memory-recall-based arithmetic learning. These behavioral improvements were associated with defined hemodynamic responses consistent with more efficient neurovascular coupling within the left DLPFC. Testing 6 months after training revealed long-lasting behavioral and physiological modifications in the stimulated group relative to sham controls for trained and nontrained calculation material. These results demonstrate that, depending on the learning regime, TRNS can induce long-term enhancement of cognitive and brain functions. Such findings have significant implications for basic and translational neuroscience, highlighting TRNS as a viable approach to enhancing learning and high-level cognition by the long-term modulation of neuroplasticity.

Snowball, Albert; Tachtsidis, Ilias; Popescu, Tudor; Thompson, Jacqueline; Delazer, Margarete; Zamarian, Laura; Zhu, Tingting; Cohen Kadosh, Roi

2013-01-01

323

Towards a Functional Understanding of Protein N-Terminal Acetylation  

PubMed Central

Protein N-terminal acetylation is a major modification of eukaryotic proteins. Its functional implications include regulation of protein–protein interactions and targeting to membranes, as demonstrated by studies of a handful of proteins. Fifty years after its discovery, a potential general function of the N-terminal acetyl group carried by thousands of unique proteins remains enigmatic. However, recent functional data suggest roles for N-terminal acetylation as a degradation signal and as a determining factor for preventing protein targeting to the secretory pathway, thus highlighting N-terminal acetylation as a major determinant for the life and death of proteins. These contributions represent new and intriguing hypotheses that will guide the research in the years to come.

Arnesen, Thomas

2011-01-01

324

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

325

CEEG Dynamic Brain Mapping, a New Method to Evaluate Brain Function in Different Psychological and Drug Conditions.  

National Technical Information Service (NTIS)

The electroencephalogram (EEG), discovered more than half a century ago, is still the only non-invasive, simple and objective method to continuously and repetitively study brain function, and has recently gained new significance since quantification by mi...

T. M. Itil K. Z. Itil E. Eralp A. Akman A. Manco

1988-01-01

326

Magnetic Resonance Imaging: From Atomic Physics to Visualization, Understanding and Treatment of Brain Disorders  

NSDL National Science Digital Library

FASEB Breakthroughs in Bioscience article. MRI is now an invaluable, noninvasive tool in the diagnosis and treatment of brain disorders. Researchers learned how to refine and interpret MRI images based on work done with animal models.

David Holzman (Federation of American Societies for Experimental Biology Office of Public Affairs)

2010-07-12

327

Understanding the Transformation of the IT Function in Organizations  

Microsoft Academic Search

Many IT researchers have tried to describe the IT function and to explain its transformation over time. Nevertheless, we observed that existing characterizations are often based on a single dimension, attached to historical periods or built into a normative discourse that calls for an ideal profile. We do not subscribe to these premises, seeing that there might be a series

Manon G. Guillemette; Guy Pare

2005-01-01

328

Associations among False Belief Understanding, Counterfactual Reasoning, and Executive Function  

ERIC Educational Resources Information Center

The primary purposes of the present study were to clarify previous work on the association between counterfactual thinking and false belief performance to determine (1) whether these two variables are related and (2) if so, whether executive function skills mediate the relationship. A total of 92 3-, 4-, and 5-year-olds completed false belief,…

Guajardo, Nicole R.; Parker, Jessica; Turley-Ames, Kandi

2009-01-01

329

Towards an understanding of cognitive function in Friedreich ataxia  

Microsoft Academic Search

There is limited documentation regarding cognitive function in individuals with Friedreich ataxia (FRDA), possibly because FRDA is widely held to predominantly affect the spinal cord, peripheral sensory nerves and cerebellum and not to affect cognition. Traditionally, the cerebellum has been thought to coordinate voluntary movement and motor tone, posture and gait. However, recent studies have implicated the cerebellum in a

Louise A. Corben; Nellie Georgiou-Karistianis; Michael C. Fahey; Elsdon Storey; Andrew Churchyard; Malcolm Horne; John L. Bradshaw; Martin B. Delatycki

2006-01-01

330

Proteomics – post-genomic cartography to understand gene function  

Microsoft Academic Search

The completion of the genomic sequences of numerous organisms from human and mouse to Caenorhabditis elegans and many microorganisms, and the definition of their genes provides a database to interpret cellular protein-expression patterns and relate them to protein function. Proteomics technologies that are dependent on mass spectrometry and involve two-dimensional gel electrophoresis are providing the main window into the world

Soren Naaby-Hansen; Michael D. Waterfield; Rainer Cramer

2001-01-01

331

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

332

Functional Causal Mediation Analysis With an Application to Brain Connectivity  

PubMed Central

Mediation analysis is often used in the behavioral sciences to investigate the role of intermediate variables that lie on the causal path between a randomized treatment and an outcome variable. Typically, mediation is assessed using structural equation models (SEMs), with model coefficients interpreted as causal effects. In this article, we present an extension of SEMs to the functional data analysis (FDA) setting that allows the mediating variable to be a continuous function rather than a single scalar measure, thus providing the opportunity to study the functional effects of the mediator on the outcome. We provide sufficient conditions for identifying the average causal effects of the functional mediators using the extended SEM, as well as weaker conditions under which an instrumental variable estimand may be interpreted as an effect. The method is applied to data from a functional magnetic resonance imaging (fMRI) study of thermal pain that sought to determine whether activation in certain brain regions mediated the effect of applied temperature on self-reported pain. Our approach provides valuable information about the timing of the mediating effect that is not readily available when using the standard nonfunctional approach. To the best of our knowledge, this work provides the first application of causal inference to the FDA framework.

Lindquist, Martin A.

2014-01-01

333

The Contribution of Immediate Early Genes to the Understanding of Brain Processing of Stressors  

Microsoft Academic Search

The data discussed above indicate that the study of c-fos expression has greatly contributed to our knowledge of the brain processing of stressors. The use of IEGs other than c-fos (e.g., zif268, arc) reveals activation of brain areas not detected with c-fos, even though evaluation of other markers of neuronal activation (for example, phosphorylation of CREB) could be important\\u000a in

Antonio Armario

334

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.

Nunez, Yury O.; Mayfield, R. Dayne

2012-01-01

335

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.

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

336

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.

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

2011-01-01

337

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

338

Physical Activity, Cognitive Function, and Brain Health: What Is the Role of Exercise Training in the Prevention of Dementia?  

PubMed Central

The population of elderly adults in the US is growing, and the prevalence of age-related cognitive decline and dementia is expected to increase in turn. Effective and inexpensive interventions or preventive measures are necessary to attenuate the increased economic and social burden of dementia. This review will focus on the potential for physical activity and exercise training to promote brain health and improve cognitive function via neurophysiological changes. We will review pertinent animal and human research examining the effects of physical activity on cognitive function and neurophysiology. We will discuss cross-sectional and longitudinal studies addressing the relationship between neurocognitive health and cardiorespiratory fitness or habitual activity level. We will then present and discuss longitudinal investigations examining the effects of exercise training on cognitive function and neurophysiology. We will conclude by summarizing our current understanding of the relationship between physical activity and brain health, and present areas for future research given the current gaps in our understanding of this issue.

Gregory, Sara M.; Parker, Beth; Thompson, Paul D.

2012-01-01

339

ORIGINAL RESEARCH Restored Activation of Primary Motor Area from Motor Reorganization and Improved Motor Function after Brain Tumor Resection  

Microsoft Academic Search

BACKGROUND AND PURPOSE: Reorganization of brain function may result in preservation of motor function in patients with brain tumors. The goal of the present study was to investigate whether function of the primary motor area (M1) was restored and whether motor function improved after brain tumor resection. METHODS: Five patients with metastatic brain tumors located within or near M1 underwent

N. Shinoura; Y. Suzuki; R. Yamada; T. Kodama; M. Takahashi; K. Yagi

340

Oxygen Flux Analysis to Understand the Biological Function of Sirtuins  

PubMed Central

The sirtuins are a family of highly conserved NAD+-dependent lysine deacylases with important roles in metabolic regulation. Of the seven mammalian sirtuins, three localize to the mitochondria: SIRT3, SIRT4, and SIRT5. Mitochondrial sirtuins are crucial regulators of the metabolic network that controls energy homeostasis and impacts cancer, obesity, diabetes, mitochondrial diseases, metabolic disorders, and many other human diseases of aging. To best study the mitochondrial function of the sirtuins, we have employed an oxygen flux analyzer as a tool to track and record the extracellular oxygen consumption rate and acidification rate that reflects mitochondrial respiration and glycolysis, respectfully. Here we described the methods using this assay to study the substrate utilization and mitochondrial function in a human hepato-cellular carcinoma cell line, Huh7. Additionally, we have generated a stable SIRT4 knocked-down Huh7 cell line. With this cell line, we evaluated how the absence of SIRT4 affects mitochondrial function, glucose utilization, glutamine oxidation, and fatty acid oxidation in these cells.

Wang, Dongning; Green, Michelle F.; McDonnell, Eoin; Hirschey, Matthew D.

2013-01-01

341

Imaging brain neuronal activity using functionalized magnetonanoparticles and MRI.  

PubMed

This study explored the use of non-radioactive 2-deoxy glucose (2DG)-labeled magnetonanoparticles (MNP) and magnetic resonance imaging (MRI) to detect functional activity during rest, peripheral stimulation, and epileptic seizures, in animal models. Non-radioactive 2DG was covalently attached to magnetonanoparticles composed of iron oxide and dextran and intravenous (tail) injections were performed. 2DG-MNP was injected in resting and stimulated naïve rodents and the subsequent MRI was compared to published (14)C-2DG autoradiography data. Reproducibility and statistical significance was established in one studied model. Negative contrast enhancement (NCE) in acute seizures and chronic models of epilepsy were investigated. MRI NCE due to 2DG-MNP particles was compared to that of plain (unconjugated) MNP in one animal. NCE due to 2DG-MNP particles at 3 T, which is approved for human use, was also investigated. Histology showed presence of MNP (following intravenous injection) in the brain tissues of resting naïve animal. 2DG-MNP intraparenchymal uptake was visible on MRI and histology. The locations of NCE agreed with published results of 2DG autoradiography in resting and stimulated animals and epileptic rats. Localization of epileptogenicity was confirmed by subsequent depth-electrode EEG (iEEG). Non-radioactive 2DG-MNP can cross the blood-brain barrier (BBB) and may accurately localize areas of increased activity. Although, this proof-of-principle study involves only a limited number of animals, and much more research and quantification are necessary to demonstrate that 2DG-MNP, or MNPs conjugated with other ligands, could eventually be used to image localized cerebral function with MRI in humans, this MNP-MRI approach is potentially applicable to the use of many bioactive molecules as ligands for imaging normal and abnormal localized cerebral functions. PMID:22622772

Akhtari, Massoud; Bragin, Anatol; Moats, Rex; Frew, Andrew; Mandelkern, Mark

2012-10-01

342

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

343

Cognitive and sexual functions in patients with traumatic brain injury  

PubMed Central

Background: Traumatic brain injury (TBI) has an immense psychosocial impact on an individual as well as on the close relatives. Sexuality is one among the functions which are usually found compromised post injury. The aim of present study was to examine cognitive and sexual functions post TBI. The objective of the study was to explore these domains and their relationship with each other. Tools: The tools used were sociodemographics record sheet, Edinburg handedness inventory, brief sexual function inventory, depression anxiety stress scales-21 and NIMHANS head injury battery. The sample consisted of 30 patients with mild-to-moderate TBI. All the subjects were tested individually in their regional language. Results: On cognitive domain, patients performed inadequately on all the tests; however, the percentage was higher in mental speed (43.3%), sustained attention (26.7%), verbal working memory (30%), response inhibition (36.7%), verbal memory (immediate and delayed) (43%) and visual (immediate, 23.3% and delayed, 26.7%). On the domain of sexual functions, all the four domains (sexual drive, erection, ejaculation and problem assessment) were affected however overall satisfaction (93.3%) was adequate. Among the four domains higher percentage of involvement was noted on problem assessment (70%), ejaculation (56.7%), and erection (46.7%). Significant correlation was found between mental speed, verbal working memory, planning, and visual memory with sexual drive, erection, ejaculation and overall satisfaction domains of sexual functioning. Negative correlation was found between motor speed and sustained attention with sexual drive, erection and ejaculation. Conclusion: Both cognitive and sexual functioning were found effected post TBI. However less emphasis is given to sexual functioning by the professionals. Educational intervention is needed to sensitize professional about this area and to include this area for better management.

War, Firdous A.; Jamuna, R.; Arivazhagan, A.

2014-01-01

344

Significance of vitamin A to brain function, behavior and learning  

PubMed Central

Retinoid acid, the bioactive metabolite of vitamin A, is a potent signaling molecule in the brains of growing and adult animals, regulates numerous gene products, and modulates neurogenesis, neuronal survival and synaptic plasticity. Vitamin A deficiency (VAD) is a global health problem, yet our knowledge of its effects on behavior and learning is still emerging. Here we review studies that have implicated retinoids in learning and memory deficits of post-embryonic and adult rodent and songbird models. Dietary vitamin A supplementation improves learning and memory in VAD rodents and can ameliorate cognitive declines associated with normal aging. Songbird studies examine the effects of retinoid signaling on vocal/auditory learning and are uniquely suited to study the behavioral effects of VAD because the neural circuitry of the song system is discrete and well understood. Similar to human speech acquisition, avian vocal learning proceeds in well-defined stages of template acquisition, rendition and maturation. Local blockade of retinoic acid production in the brain or excess dietary retinoic acid results in the failure of song maturation, yet does not affect prior song acquisition. Together these results yield significant insights into the role of vitamin A in maintaining neuronal plasticity and cognitive function in adulthood.

Olson, Christopher R.; Mello, Claudio V.

2011-01-01

345

Predicting regional neurodegeneration from the healthy brain functional connectome  

PubMed Central

Summary Neurodegenerative diseases target large-scale neural networks. Four competing mechanistic hypotheses have been proposed to explain network-based disease patterning: nodal stress, transneuronal spread, trophic failure, and shared vulnerability. Here, we used task-free fMRI to derive the healthy intrinsic connectivity patterns seeded by brain regions vulnerable to any of five distinct neurodegenerative diseases. These data enabled us to investigate how intrinsic connectivity in health predicts region-by-region vulnerability to disease. For each illness, specific regions emerged as critical network “epicenters” whose normal connectivity profiles most resembled the disease-associated atrophy pattern. Graph theoretical analyses in healthy subjects revealed that regions with higher total connectional flow and, more consistently, shorter functional paths to the epicenters, showed greater disease-related vulnerability. These findings best fit a transneuronal spread model of network-based vulnerability. Molecular pathological approaches may help clarify what makes each epicenter vulnerable to its targeting disease and how toxic protein species travel between networked brain structures.

Zhou, Juan; Gennatas, Efstathios D.; Kramer, Joel H.; Miller, Bruce L.; Seeley, William W.

2012-01-01

346

Memory Networks in Tinnitus: A Functional Brain Image Study  

PubMed Central

Tinnitus is characterized by the perception of sound in the absence of an external auditory stimulus. The network connectivity of auditory and non-auditory brain structures associated with emotion, memory and attention are functionally altered in debilitating tinnitus. Current studies suggest that tinnitus results from neuroplastic changes in the frontal and limbic temporal regions. The objective of this study was to use Single-Photon Emission Computed Tomography (SPECT) to evaluate changes in the cerebral blood flow in tinnitus patients with normal hearing compared with healthy controls. Methods: Twenty tinnitus patients with normal hearing and 17 healthy controls, matched for sex, age and years of education, were subjected to Single Photon Emission Computed Tomography using the radiotracer ethylenedicysteine diethyl ester, labeled with Technetium 99 m (99 mTc-ECD SPECT). The severity of tinnitus was assessed using the “Tinnitus Handicap Inventory” (THI). The images were processed and analyzed using “Statistical Parametric Mapping” (SPM8). Results: A significant increase in cerebral perfusion in the left parahippocampal gyrus (pFWE <0.05) was observed in patients with tinnitus compared with healthy controls. The average total THI score was 50.8+18.24, classified as moderate tinnitus. Conclusion: It was possible to identify significant changes in the limbic system of the brain perfusion in tinnitus patients with normal hearing, suggesting that central mechanisms, not specific to the auditory pathway, are involved in the pathophysiology of symptoms, even in the absence of clinically diagnosed peripheral changes.

Laureano, Maura Regina; Onishi, Ektor Tsuneo; Bressan, Rodrigo Affonseca; Castiglioni, Mario Luiz Vieira; Batista, Ilza Rosa; Reis, Marilia Alves; Garcia, Michele Vargas; de Andrade, Adriana Neves; de Almeida, Roberta Ribeiro; Garrido, Griselda J.; Jackowski, Andrea Parolin

2014-01-01

347

Selectionist and evolutionary approaches to brain function: a critical appraisal.  

PubMed

We consider approaches to brain dynamics and function that have been claimed to be Darwinian. These include Edelman's theory of neuronal group selection, Changeux's theory of synaptic selection and selective stabilization of pre-representations, Seung's Darwinian synapse, Loewenstein's synaptic melioration, Adam's selfish synapse, and Calvin's replicating activity patterns. Except for the last two, the proposed mechanisms are selectionist but not truly Darwinian, because no replicators with information transfer to copies and hereditary variation can be identified in them. All of them fit, however, a generalized selectionist framework conforming to the picture of Price's covariance formulation, which deliberately was not specific even to selection in biology, and therefore does not imply an algorithmic picture of biological evolution. Bayesian models and reinforcement learning are formally in agreement with selection dynamics. A classification of search algorithms is shown to include Darwinian replicators (evolutionary units with multiplication, heredity, and variability) as the most powerful mechanism for search in a sparsely occupied search space. Examples are given of cases where parallel competitive search with information transfer among the units is more efficient than search without information transfer between units. Finally, we review our recent attempts to construct and analyze simple models of true Darwinian evolutionary units in the brain in terms of connectivity and activity copying of neuronal groups. Although none of the proposed neuronal replicators include miraculous mechanisms, their identification remains a challenge but also a great promise. PMID:22557963

Fernando, Chrisantha; Szathmáry, Eörs; Husbands, Phil

2012-01-01

348

Eye and visual function in traumatic brain injury.  

PubMed

Combat blast is an important cause of traumatic brain injury (TBI) in the Department of Veterans Affairs polytrauma population, whereas common causes of TBI in the civilian sector include motor vehicle accidents and falls. Known visual consequences of civilian TBI include compromised visual acuity, visual fields, and oculomotor function. The visual consequences of TBI related to blast remain largely unknown. Blast injury may include open globe (eye) injury, which is usually detected and managed early in the rehabilitation journey. The incidence, locations, and types of ocular damage in eyes without open globe injury after exposure to powerful blast have not been systematically studied. Initial reports and preliminary data suggest that binocular function, visual fields, and other aspects of visual function may be impaired after blast-related TBI, despite relatively normal visual acuity. Damage to the ocular tissues may occur from blunt trauma without rupture or penetration (closed globe injury). Possible areas for research are development of common taxonomy and assessment tools across services, surgical management, and outcomes for blast-related eye injury; the incidence, locations, and natural history of closed globe injury; binocular and visual function impairment; quality of life in affected service members; pharmacological and visual therapies; and practice patterns for screening, management, and rehabilitation. PMID:20104404

Cockerham, Glenn C; Goodrich, Gregory L; Weichel, Eric D; Orcutt, James C; Rizzo, Joseph F; Bower, Kraig S; Schuchard, Ronald A

2009-01-01

349

Methamphetamine disrupts blood brain barrier function by induction of oxidative stress in brain endothelial cells  

PubMed Central

Methamphetamine (METH), a potent stimulant with strong euphoric properties, has a high abuse liability and long-lasting neurotoxic effects. Recent studies in animal models have indicated that METH can induce impairment of the blood brain barrier (BBB), thus suggesting that some of the neurotoxic effects resulting from METH abuse could be the outcome of barrier disruption. Here we provide evidence that METH alters BBB function via direct effects on endothelial cells and explore possible underlying mechanisms leading to endothelial injury. We report that METH increases BBB permeability in vivo, and exposure of primary human microvascular endothelial cells (BMVEC) to METH diminishes tightness of BMVEC monolayers in a dose- and time-dependent manner by decreasing expression of cell membrane associated tight junction (TJ) proteins. These changes were accompanied by enhanced production of reactive oxygen species, increased monocyte migration across METH-treated endothelial monolayers, and activation of myosin light chain kinase (MLCK) in BMVEC. Anti-oxidant treatment attenuated or completely reversed all tested aspects of METH induced BBB dysfunction. Our data suggest that BBB injury is caused by METH-mediated oxidative stress, which activates MLCK and negatively affects the TJ complex. These observations provide a basis for antioxidant protection against brain endothelial injury caused by METH exposure.

Ramirez, Servio H.; Potula, Raghava; Fan, Shongshan; Eidem, Tess; Papugani, Anil; Reichenbach, Nancy; Dykstra, Holly; Weksler, Babette B.; Romero, Ignacio A.; Couraud, Pierre O.; Persidsky, Yuri

2012-01-01

350

Problems in understanding the organization, structure and function of chromosomes  

SciTech Connect

Despite intensive investigation of mammalian chromosomes, we are still largely ignorant of the basic rules that govern their organization, structure, and functions. This situation results from the current limitations in available technologies to elucidate the structures of such complex biological systems. Whereas the powerful techniques of molecular biology have successfully addressed at high resolution functional problems at the level of nucleic acid sequences, many lower resolution questions concerning the architecture of the cell nucleus, long range order in chromosomes, and higher order chromatin structures remain largely unanswered. Techniques are now emerging that should help to remedy this situation. The use of confocal microscopy with molecular probes will tell us at the level of the light microscope a great deal about the organization of the nucleus and how it changes in different cell types; advanced light sources have the potential to image hydrated biological systems down to 10 nm, and scanning electron tunneling and atomic force microscopies have demonstrated their ability to image molecules though their ability to usefully image biomolecules such as DNA remains to be demonstrated. 32 refs., 6 figs.

Bradbury, E.M. (Lawrence Livermore National Lab., CA (USA) California Univ., Davis, CA (USA))

1990-01-01

351

Lymph node dissection - understanding the immunological function of lymph nodes  

PubMed Central

Lymph nodes (LN) are one of the important sites in the body where immune responses to pathogenic antigens are initiated. This immunological function induced by cells within the LN is an extensive area of research. To clarify the general function of LN, to identify cell populations within the lymphatic system and to describe the regeneration of the lymph vessels, the experimental surgical technique of LN dissection has been established in various animal models. In this review different research areas in which LN dissection is used as an experimental tool will be highlighted. These include regeneration studies, immunological analysis and studies with clinical questions. LN were dissected in order to analyse the different cell subsets of the incoming lymph in detail. Furthermore, LN were identified as the place where the induction of an antigen-specific response occurs and, more significantly, where this immune response is regulated. During bacterial infection LN, as a filter of the lymph system, play a life-saving role. In addition, LN are essential for the induction of tolerance against harmless antigens, because tolerance could not be induced in LN-resected animals. Thus, the technique of LN dissection is an excellent and simple method to identify the important role of LN in immune responses, tolerance and infection.

Buettner, M; Bode, U

2012-01-01

352

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.

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

2013-01-01

353

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.

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

2013-01-01

354

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

355

Anatomic standardization: Linear scaling and nonlinear warping of functional brain images  

Microsoft Academic Search

An automated method was proposed for anatomic standardization of PET scans in three dimensions, which enabled objective intersubject and cross-group comparisons of functional brain images. The method involved linear scaling to correct for individual brain size and nonlinear warping to minimize regional anatomic variations among subjects. In the linear-scaling step, the anteroposterior length and width of the brain were measured

Satoshi Minoshima; Robert A. Koeppe; Kirk A. Frey

1994-01-01

356

Ising-like dynamics in large-scale functional brain networks  

Microsoft Academic Search

Brain ``rest'' is defined---more or less unsuccessfully---as the state in which there is no explicit brain input or output. This work focuses on the question of whether such state can be comparable to any known dynamical state. For that purpose, correlation networks from human brain functional magnetic resonance imaging are contrasted with correlation networks extracted from numerical simulations of the

Daniel Fraiman; Pablo Balenzuela; Jennifer Foss; Dante R. Chialvo

2009-01-01

357

Resting state magnetoencephalography functional connectivity in traumatic brain injury  

PubMed Central

Object Traumatic brain injury (TBI) is one of the leading causes of morbidity worldwide. One mechanism by which blunt head trauma may disrupt normal cognition and behavior is through alteration of functional connectivity between brain regions. In this pilot study, the authors applied a rapid automated resting state magnetoencephalography (MEG) imaging technique suitable for routine clinical use to test the hypothesis that there is decreased functional connectivity in patients with TBI compared with matched controls, even in cases of mild TBI. Furthermore, they posit that these abnormal reductions in MEG functional connectivity can be detected even in TBI patients without specific evidence of traumatic lesions on 3-T MR images. Finally, they hypothesize that the reductions of functional connectivity can improve over time across serial MEG scans during recovery from TBI. Methods Magnetoencephalography maps of functional connectivity in the alpha (8- to 12-Hz) band from 21 patients who sustained a TBI were compared with those from 18 age- and sex-matched controls. Regions of altered functional connectivity in each patient were detected in automated fashion through atlas-based registration to the control database. The extent of reduced functional connectivity in the patient group was tested for correlations with clinical characteristics of the injury as well as with findings on 3-T MRI. Finally, the authors compared initial connectivity maps with 2-year follow-up functional connectivity in a subgroup of 5 patients with TBI. Results Fourteen male and 7 female patients (17–53 years old, median 29 years) were enrolled. By Glasgow Coma Scale (GCS) criteria, 11 patients had mild, 1 had moderate, and 3 had severe TBI, and 6 had no GCS score recorded. On 3-T MRI, 16 patients had abnormal findings attributable to the trauma and 5 had findings in the normal range. As a group, the patients with TBI had significantly lower functional connectivity than controls (p < 0.01). Three of the 5 patients with normal findings on 3-T MRI showed regions of abnormally reduced MEG functional connectivity. No significant correlations were seen between extent of functional disconnection and injury severity or posttraumatic symptoms (p > 0.05). In the subgroup undergoing 2-year follow-up, the second MEG scan demonstrated a significantly lower percentage of voxels with decreased connectivity (p < 0.05) than the initial MEG scan. Conclusions A rapid automated resting-state MEG imaging technique demonstrates abnormally decreased functional connectivity that may persist for years after TBI, including cases classified as “mild” by GCS criteria. Disrupted MEG connectivity can be detected even in some patients with normal findings on 3-T MRI. Analysis of follow-up MEG scans in a subgroup of patients shows that, over time, the abnormally reduced connectivity can improve, suggesting neuroplasticity during the recovery from TBI. Resting state MEG deserves further investigation as a prognostic and predictive biomarker for TBI.

Tarapore, Phiroz E.; Findlay, Anne M.; LaHue, Sara C.; Lee, Hana; Honma, Susanne M.; Mizuiri, Danielle; Luks, Tracy L.; Manley, Geoffrey T.; Nagarajan, Srikantan S.; Mukherjee, Pratik

2014-01-01

358

Emission Computerized-Tomography and Determination of Local Brain Function.  

National Technical Information Service (NTIS)

Methods for the three dimensional reconstruction of /sup 99m/Tc brain scans are described. The diagnostic advantages of computerized tomography in the localization of brain tumors and in measurements of local cerebral blood flow are discussed.

D. E. Kuhl A. Alavi M. Reivich R. Q. Edwards C. A. Fenton

1975-01-01

359

Distributed representations in memory: insights from functional brain imaging.  

PubMed

Forging new memories for facts and events, holding critical details in mind on a moment-to-moment basis, and retrieving knowledge in the service of current goals all depend on a complex interplay between neural ensembles throughout the brain. Over the past decade, researchers have increasingly utilized powerful analytical tools (e.g., multivoxel pattern analysis) to decode the information represented within distributed functional magnetic resonance imaging activity patterns. In this review, we discuss how these methods can sensitively index neural representations of perceptual and semantic content and how leverage on the engagement of distributed representations provides unique insights into distinct aspects of memory-guided behavior. We emphasize that, in addition to characterizing the contents of memories, analyses of distributed patterns shed light on the processes that influence how information is encoded, maintained, or retrieved, and thus inform memory theory. We conclude by highlighting open questions about memory that can be addressed through distributed pattern analyses. PMID:21943171

Rissman, Jesse; Wagner, Anthony D

2012-01-01

360

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.

Zhao, Xin; Zhou, Renlai; Fu, Li

2013-01-01

361

Colorful brains: 14 years of display practice in functional neuroimaging.  

PubMed

Neuroimaging results are typically graphically rendered and color-coded, which influences the process of knowledge generation within neuroscience as well as the public perception of brain research. Analyzing these issues requires empirical information on the display practice in neuroimaging. In our study we evaluated more than 9000 functional images (fMRI and PET) published between 1996 and 2009 with respect to the use of color, image structure, image production software and other factors that may determine the display practice. We demonstrate a variety of display styles despite a remarkable dominance of few image production sites and software systems, outline some tendencies of standardization, and identify shortcomings with respect to color scale explication in neuroimages. We discuss the importance of the finding for knowledge production in neuroimaging, and we make suggestions to improve the display practice in neuroimaging, especially on regimes of color coding. PMID:23403183

Christen, Markus; Vitacco, Deborah A; Huber, Lara; Harboe, Julie; Fabrikant, Sara I; Brugger, Peter

2013-06-01

362

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

363

Correspondence between structure and function in the human brain at rest.  

PubMed

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

364

Analysis of Functional Pathways Altered after Mild Traumatic Brain Injury  

PubMed Central

Abstract 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.

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

2013-01-01

365

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

366

Pulmonary Function, Cognitive Impairment and Brain Atrophy in a Middle-Aged Community Sample  

Microsoft Academic Search

Objective: To determine the relationship of lung function to brain anatomical parameters and cognitive function and to examine the mediating factors for any relationships. Methods: A random sub-sample of 469 persons (men = 252) aged 60–64 years from a larger community sample underwent brain magnetic resonance imaging scans and pulmonary function tests (forced vital capacity, FVC, forced expiratory volume in

P. S. Sachdev; K. J. Anstey; R. A. Parslow; W. Wen; J. Maller; R. Kumar; H. Christensen; A. F. Jorm

2006-01-01

367

Spectral clustering approach with sparsifying technique for functional connectivity detection in the resting brain  

Microsoft Academic Search

The aim of this study is to assess the functional connectivity from resting state functional magnetic resonance imaging (fMRI) data. Spectral clustering algorithm was applied to the realistic and real fMRI data acquired from a resting healthy subject to find functionally connected brain regions. In order to make computation of the spectral decompositions of the entire brain volume feasible, the

Mahdi Ramezani; Amin Heidari; Emad Fatemizadeh; Hamid Soltanian-Zadeh

2010-01-01

368

Electromagnetic brain mapping  

Microsoft Academic Search

There has been tremendous advances in our ability to produce images of human brain function. Applications of functional brain imaging extend from improving our understanding of the basic mechanisms of cognitive processes to better characterization of pathologies that impair normal function. Magnetoencephalography (MEG) and electroencephalography (EEG) (MEG\\/EEG) localize neural electrical activity using noninvasive measurements of external electromagnetic signals. Among the

S. Baillet; J. C. Mosher; R. M. Leahy

2001-01-01

369

Functional outcomes in schizophrenia: understanding the competence-performance discrepancy.  

PubMed

A problem in the study and treatment of functional disability in schizophrenia is that factors other than competence (what one can do) can limit real-world performance (what one does). We examined predictors of the competence-performance discrepancy in both adaptive and interpersonal domains. Patients with schizophrenia (N = 96) were evaluated at baseline of a clinical treatment study. Discrepancy scores were created by considering each subject's competence relative to their real-world performance in interpersonal and adaptive behaviour domains. Logistic regression analyses revealed that for the interpersonal competence-performance discrepancy, living in a group home, better neurocognition, more time spent in the hospital since a first episode of psychosis, and a longer first hospitalization predicted a greater discrepancy between interpersonal competence and performance measures. For adaptive behaviour, shorter time since most recent hospitalization, more depressive symptoms, greater number of months of first hospitalization, older age at baseline, younger age at first hospitalization, and more time spent in the hospital since a first episode of psychosis predicted a greater adaptive competence-performance discrepancy. A different pattern of demographic and clinical features may limit the extent to which patients are deploying interpersonal versus adaptive skills in everyday life. PMID:21944429

Gupta, Maya; Bassett, Emma; Iftene, Felicia; Bowie, Christopher R

2012-02-01

370

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.

2013-01-01

371

Reorganization of functional brain maps after exercise training: Importance of cerebellar-thalamic-cortical pathway.  

PubMed

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/s, while control animals (n=10) walked for 1 min/day at 1.2 cm/s. Six weeks later, [(14)C]-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, D P; Yang, J; Guo, Y; Maarek, J-M I

2007-12-12

372

Does function follow form?: Methods to fuse structural and functional brain images show decreased linkage in schizophrenia  

Microsoft Academic Search

When both structural magnetic resonance imaging (sMRI) and functional MRI (fMRI) data are collected they are typically analyzed separately and the joint information is not examined. Techniques that examine joint information can help to find hidden traits in complex disorders such as schizophrenia. The brain is vastly interconnected, and local brain morphology may influence functional activity at distant regions. In

Andrew M. Michael; Stefi A. Baum; Tonya White; Oguz Demirci; Nancy C. Andreasen; Judith M. Segall; Rex E. Jung; Godfrey Pearlson; Vince P. Clark; Randy L. Gollub; S. Charles Schulz; Joshua L. Roffman; Kelvin O. Lim; Beng-Choon Ho; H. Jeremy Bockholt; Vince D. Calhoun

2010-01-01

373

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

374

Understanding in an Instant: Neurophysiological Evidence for Mechanistic Language Circuits in the Brain  

ERIC Educational Resources Information Center

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…

Pulvermuller, Friedemann; Shtyrov, Yury; Hauk, Olaf

2009-01-01

375

Traumatic Experience and the Brain: A Handbook for Understanding and Treating Those Traumatized as Children.  

ERIC Educational Resources Information Center

This book is the result of the authors three decades of experience with children traumatized by abuse and/or neglect. This book details the effect of such trauma on the developing brain, describing how it actually rewires one's perceptions of self, others, and the world. Based upon research and clinical experience, it describes the impact of…

Ziegler, Dave

376

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

377

Hypoglycaemia-induced changes in regional brain volume and memory function  

PubMed Central

Background Hypoglycaemic events can be a serious complication of insulin therapy in Type 1 diabetes mellitus. Severe hypoglycaemic exposure can lead to episodic memory impairments, including anterograde amnesia. However, relatively little is known regarding the long-term impact of severe hypoglycaemia on brain structure in Type 1 diabetes mellitus. The goals of the present study were to gain a greater understanding of the long-term effects of severe hypoglycaemia exposure on brain structure and the neural correlates of memory impairments in Type 1 diabetes mellitus. Case report Regional grey and white matter volume and total white matter lesion volume were quantified in an individual with long-standing hypoglycaemia-induced anterograde amnesia and compared with age- and gender-matched healthy control subjects. Our patient has significant reductions in grey matter volume in the hippocampus, thalamus and pallidum, and significant reductions in white matter volume in the splenium, isthmus of the cingulate and cerebellum. He also has a significantly larger total white matter lesion volume than control subjects. Conclusion This case study highlights the potential of hypoglycaemia for permanent deleterious effects on brain structure and memory function. Our results suggest that subcortical grey matter, periventricular white matter and posterior white matter may be most susceptible to injury from hypoglycaemia exposure, and that structural damage to the hippocampus and isthmus of the cingulate may play a central role in hypoglycaemia-induced memory impairments.

Kirchhoff, B. A.; Lugar, H. M.; Smith, S. E.; Meyer, E. J.; Perantie, D. C.; Kolody, B. C.; Koller, J. M.; Arbelaez, A. M.; Shimony, J. S.; Hershey, T.

2013-01-01

378

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.

Magistretti, P J; Pellerin, L

1999-01-01

379

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

380

Neuroimaging in Pediatric Traumatic Brain Injury: Current and Future Predictors of Functional Outcome  

ERIC Educational Resources Information Center

Although neuroimaging has long played a role in the acute management of pediatric traumatic brain injury (TBI), until recently, its use as a tool for understanding and predicting long-term brain-behavior relationships after TBI has been limited by the relatively poor sensitivity of routine clinical imaging for detecting diffuse axonal injury…

Suskauer, Stacy J.; Huisman, Thierry A. G. M.

2009-01-01

381

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

PubMed Central

Memory problems are one of the most common symptoms of sport-related mild traumatic brain injury (MTBI), known as concussion. Surprisingly, little research has examined spatial memory in concussed athletes given its importance in athletic environments. Here, we combine functional magnetic resonance imaging (fMRI) with a virtual reality (VR) paradigm designed to investigate the possibility of residual functional deficits in recently concussed but asymptomatic individuals. Specifically, we report performance of spatial memory navigation tasks in a VR environment and fMRI data in 15 athletes suffering from MTBI and 15 neurologically normal, athletically active age matched controls. No differences in performance were observed between these two groups of subjects in terms of success rate (94 and 92%) and time to complete the spatial memory navigation tasks (mean = 19.5 and 19.7 s). Whole brain analysis revealed that similar brain activation patterns were observed during both encoding and retrieval among the groups. However, concussed athletes showed larger cortical networks with additional increases in activity outside of the shared region of interest (ROI) during encoding. Quantitative analysis of blood oxygen level dependent (BOLD) signal revealed that concussed individuals had a significantly larger cluster size during encoding at parietal cortex, right dorsolateral prefrontal cortex, and right hippocampus. In addition, there was a significantly larger BOLD signal percent change at the right hippocampus. Neither cluster size nor BOLD signal percent change at shared ROIs was different between groups during retrieval. These major findings are discussed with respect to current hypotheses regarding the neural mechanism responsible for alteration of brain functions in a clinical setting.

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

2010-01-01

382

Thalamic Resting-State Functional Networks: Disruption in Patients with Mild Traumatic Brain Injury  

PubMed Central

Purpose: To explore the neural correlates of the thalamus by using resting-state functional magnetic resonance (MR) imaging and to investigate whether thalamic resting-state networks (RSNs) are disrupted in patients with mild traumatic brain injury (MTBI). Materials and Methods: This HIPAA-compliant study was approved by the institutional review board, and written informed consent was obtained from 24 patients with MTBI and 17 healthy control subjects. The patients had varying degrees of symptoms, with a mean disease duration of 22 days. The resting-state functional MR imaging data were analyzed by using a standard seed-based whole-brain correlation method to characterize thalamic RSNs. Student t tests were used to perform comparisons. The association between thalamic RSNs and performance on neuropsychologic and neurobehavioral measures was also investigated in patients with MTBI by using Spearman rank correlation. Results: A normal pattern of thalamic RSNs was demonstrated in healthy subjects. This pattern was characterized as representing relatively symmetric and restrictive functional thalamocortical connectivity, suggesting an inhibitory property of the thalamic neurons during the resting state. This pattern was disrupted, with significantly increased thalamic RSNs (P ? .005) and decreased symmetry (P = .03) in patients with MTBI compared with healthy control subjects. Increased functional thalamocortical redistributive connectivity was correlated with diminished neurocognitive functions and clinical symptoms in patients with MTBI. Conclusion: These findings of abnormal thalamic RSNs lend further support to the presumed subtle thalamic injury in patients with MTBI. Resting-state functional MR imaging can be used as an additional imaging modality for detection of thalamocortical connectivity abnormalities and for better understanding of the complex persistent postconcussive syndrome. © RSNA, 2011

Tang, Lin; Sodickson, Daniel K.; Miles, Laura; Zhou, Yongxia; Reaume, Joseph; Grossman, Robert I.

2011-01-01

383

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

384

Synchronous neural interactions assessed by magnetoencephalography: a functional biomarker for brain disorders  

Microsoft Academic Search

We report on a test to assess the dynamic brain function at high temporal resolution using magnetoencephalography (MEG). The essence of the test is the measurement of the dynamic synchronous neural interactions, an essential aspect of the brain function. MEG signals were recorded from 248 axial gradiometers while 142 human subjects fixated a spot of light for 45-60 s. After

Apostolos P. Georgopoulos; Elissaios Karageorgiou; Arthur C. Leuthold; Scott M. Lewis; Joshua K. Lynch; Aurelio A. Alonso; Zaheer Aslam; Adam F. Carpenter; Angeliki Georgopoulos; Laura S. Hemmy; Ioannis G. Koutlas; Frederick J. P. Langheim; J. Riley McCarten; Susan E. McPherson; José V. Pardo; Patricia J. Pardo; Gareth J. Parry; Susan J. Rottunda; Barbara M. Segal; Scott R. Sponheim; John J. Stanwyck; Massoud Stephane; Joseph J. Westermeyer

2007-01-01

385

Brain–machine interfaces to restore motor function and probe neural circuits  

Microsoft Academic Search

Recent studies have shown that it is possible to create functional, bidirectional, real-time interfaces between living brain tissue and artificial devices. It is reasonable to predict that further research on brain–machine interfaces will lead to the development of a new generation of neuroprosthetic devices aimed at restoring motor functions in severely paralysed patients. In addition, I propose that such interfaces

Miguel A. L. Nicolelis

2003-01-01

386

Residual Pituitary Function after Brain Injury-Induced Hypopituitarism: A Prospective 12Month Study  

Microsoft Academic Search

Context: Traumatic brain injury (TBI) and subarachnoid hemor- rhage (SAH) are conditions at high risk for the development of hypopituitarism. Objective:The objective of the study was to clarify whether pituitary deficiencies and normal pituitary function recorded at 3 months would improve or worsen at 12 months after the brain injury. Design and Patients: Pituitary function was tested at 3 and

Gianluca Aimaretti; Maria Rosaria Ambrosio; Maurizio Gasperi; Carla Scaroni; Alessandra Fusco; Marco Faustini-Fustini; Franco Grimaldi; Francesco Logoluso; Paola Razzore; Silvia Rovere; Salvatore Benvenga; Laura De Marinis; Gaetano Lombardi; Franco Mantero; Enio Martino; Giulio Giordano; Ezio Ghigo

387

State-Dependent Changes of Connectivity Patterns and Functional Brain Network Topology in Autism Spectrum Disorder  

ERIC Educational Resources Information Center

Anatomical and functional brain studies have converged to the hypothesis that autism spectrum disorders (ASD) are associated with atypical connectivity. Using a modified resting-state paradigm to drive subjects' attention, we provide evidence of a very marked interaction between ASD brain functional connectivity and cognitive state. We show that…

Barttfeld, Pablo; Wicker, Bruno; Cukier, Sebastian; Navarta, Silvana; Lew, Sergio; Leiguarda, Ramon; Sigman, Mariano

2012-01-01

388

Toward a Neuroscope: A Real-Time Imaging System for Evaluation of Brain Function  

Microsoft Academic Search

Magnetic resonance imaging and spectroscopy techniques are now being used to detect changes in blood flow, volume and oxygenation level associated with brain function. The authors describe a prototype system, called a neuroscope, that provides a real-time acquisition, control and processing environment for functional brain studies. Preliminary experiments have shown that oxygenation sensitive changes in the rat can be captured

Clinton S. Potter; Zhi-pei Liang; Carl D. Gregory; H. Douglas Morris; Paul C. Lauterbur

1994-01-01

389

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

390

A simple view of the brain through a frequency-specific functional connectivity measure  

Microsoft Academic Search

Here we develop a measure of functional connectivity describing the degree of covariability between a brain region and the rest of the brain. This measure is based on previous formulas for the mutual information (MI) between clusters of regions in the frequency domain. Under the current scenario, the MI can be given as a simple monotonous function of the multiple

R. Salvador; A. Martínez; E. Pomarol-Clotet; J. Gomar; F. Vila; S. Sarró; A. Capdevila; E. Bullmore

2008-01-01

391

Mapping Language Function in the Brain: A Review of the Recent Literature.  

ERIC Educational Resources Information Center

Considers the potential importance of brain study for composition instruction, briefly describes functional imaging techniques, and reviews the findings of recent brain-mapping studies investigating the neurocognitive systems involved in language function. Presents a review of the recent literature and considers the possible implications of this…

Crafton, Robert E.; Kido, Elissa

2000-01-01

392

Course of functional improvement after stroke, spinal cord injury, and traumatic brain injury  

Microsoft Academic Search

Bode RK, Heinemann AW. Course of functional improvement after stroke, spinal cord injury, and traumatic brain injury. Arch Phys Med Rehabil 2002;83:100-6. Objective: To examine functional improvement patterns of persons with stroke, traumatic brain injury (TBI), and spinal cord injury (SCI). Design: Statistical analysis of data from a multisite study evaluating rehabilitation outcomes. Setting: Eight inpatient rehabilitation facilities. Participants: A

Rita K. Bode; Allen W. Heinemann

2002-01-01

393

Noninvasive laser-induced photoacoustic tomography for structural and functional in vivo imaging of the brain  

Microsoft Academic Search

Imaging techniques based on optical contrast analysis can be used to visualize dynamic and functional properties of the nervous system via optical signals resulting from changes in blood volume, oxygen consumption and cellular swelling associated with brain physiology and pathology. Here we report in vivo noninvasive transdermal and transcranial imaging of the structure and function of rat brains by means

Xueding Wang; Yongjiang Pang; Geng Ku; Xueyi Xie; George Stoica; Lihong V Wang

2003-01-01

394

Measurement of brain function of car driver using functional near-infrared spectroscopy (fNIRS).  

PubMed

The aim of this study is to propose a method for analyzing measured signal obtained from functional Near-Infrared Spectroscopy (fNIRS), which is applicable for neuroimaging studies for car drivers. We developed a signal processing method by multiresolution analysis (MRA) based on discrete wavelet transform. Statistical group analysis using Z-score is conducted after the extraction of task-related signal using MRA. Brain activities of subjects with different level of mental calculation are measured by fNIRS and fMRI. Results of mental calculation with nine subjects by using fNIRS and fMRI showed that the proposed methods were effective for the evaluation of brain activities due to the task. Finally, the proposed method is applied for evaluating brain function of car driver with and without adaptive cruise control (ACC) system for demonstrating the effectiveness of the proposed method. The results showed that frontal lobe was less active when the subject drove with ACC. PMID:19584938

Tsunashima, Hitoshi; Yanagisawa, Kazuki

2009-01-01

395

Functional brain networks and abnormal connectivity in the movement disorders.  

PubMed

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 (18)F-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

2012-10-01

396

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.

Poston, Kathleen L.; Eidelberg, David

2012-01-01

397

Reestablishing speech understanding through musical ear training after cochlear implantation: a study of the potential cortical plasticity in the brain.  

PubMed

Cochlear implants (CIs) provide impressive speech perception for persons with severe hearing loss, but many CI recipients fail in perceiving speech prosody and music. Successful rehabilitation depends on cortical plasticity in the brain and postoperative measures. The present study evaluates the behavioral and neurologic effects of musical ear training on CI users' speech and music perception. The goal is to find and work out musical methods to improve CI users' auditory capabilities and, in a longer perspective, provide an efficient strategy for improving speech understanding for both adults and children with CIs. PMID:19673820

Petersen, Bjørn; Mortensen, Malene V; Gjedde, Albert; Vuust, Peter

2009-07-01

398

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