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1

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

E-print Network

Functional specificity in the human brain: A window into the functional architecture of the mind for review February 22, 2010) Is the human mind/brain composed of a set of highly specialized components, proponents of specialized organs or modules of the mind and brain--from the phrenologists to Broca to Chomsky

Kanwisher, Nancy

2

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

PubMed

Is the human mind/brain composed of a set of highly specialized components, each carrying out a specific aspect of human cognition, or is it more of a general-purpose device, in which each component participates in a wide variety of cognitive processes? For nearly two centuries, proponents of specialized organs or modules of the mind and brain--from the phrenologists to Broca to Chomsky and Fodor--have jousted with the proponents of distributed cognitive and neural processing--from Flourens to Lashley to McClelland and Rumelhart. I argue here that research using functional MRI is beginning to answer this long-standing question with new clarity and precision by indicating that at least a few specific aspects of cognition are implemented in brain regions that are highly specialized for that process alone. Cortical regions have been identified that are specialized not only for basic sensory and motor processes but also for the high-level perceptual analysis of faces, places, bodies, visually presented words, and even for the very abstract cognitive function of thinking about another person's thoughts. I further consider the as-yet unanswered questions of how much of the mind and brain are made up of these functionally specialized components and how they arise developmentally. PMID:20484679

Kanwisher, Nancy

2010-06-22

3

Brain microenvironment promotes the final functional maturation of tumor-specific effector CD8+ T cells.  

PubMed

During the priming phase of an antitumor immune response, CD8(+) T cells undergo a program of differentiation driven by professional APCs in secondary lymphoid organs. This leads to clonal expansion and acquisition both of effector functions and a specific adhesion molecule pattern. Whether this program can be reshaped during the effector phase to adapt to the effector site microenvironment is unknown. We investigated this in murine brain tumor models using adoptive transfer of tumor-specific CD8(+) T cells, and in spontaneous immune responses of patients with malignant glioma. Our data show proliferation of Ag-experienced tumor-specific T cells within the brain parenchyma. Moreover, CD8(+) T cells further differentiated in the brain, exhibiting enhanced IFN-gamma and granzyme B expression and induction of alpha(E)(CD103)beta(7) integrin. This unexpected integrin expression identified a subpopulation of CD8(+) T cells conditioned by the brain microenvironment and also had functional consequences: alpha(E)(CD103)beta(7)-expressing CD8(+) T cells had enhanced retention in the brain. These findings were further investigated for CD8(+) T cells infiltrating human malignant glioma; CD8(+) T cells expressed alpha(E)(CD103)beta(7) integrin and granzyme B as in the murine models. Overall, our data indicate that the effector site plays an active role in shaping the effector phase of tumor immunity. The potential for local expansion and functional reprogramming should be considered when optimizing future immunotherapies for regional tumor control. PMID:17617575

Masson, Frédérick; Calzascia, Thomas; Di Berardino-Besson, Wilma; de Tribolet, Nicolas; Dietrich, Pierre-Yves; Walker, Paul R

2007-07-15

4

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

NASA Astrophysics Data System (ADS)

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

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

2010-11-01

5

Resting state functional connectivity changes induced by prior brain state are not network specific.  

PubMed

Resting state functional connectivity (rFC) is used to identify functionally related brain areas without requiring subjects to perform specific tasks. Previous work suggests that prior brain state, as determined by the activity engaged in immediately prior to collection of resting state data, can influence the networks recovered by rFC analyses. We determined the prevalence and network specificity of rFC changes induced by manipulations of prior state (including an unstructured (unconstrained) state, and language and motor tasks). Three blocks of rest data (one after each of the specified prior states) were acquired on each of 25 subjects. We hypothesised that prior state induced changes in rFC would be greatest within the networks most actively recruited by that prior state. Changes in rFC were greatest following the motor task and, contrary to our hypothesis, were not network specific. This was demonstrated by comparing (1) the timecourses within a set of ROIs selected on the basis of task-related de/activation, and (2) seed-based whole brain voxel-wise connectivity maps, seeded from local maxima in the task-related de/activation maps. Changes in connectivity strength tended to manifest as increases in rFC relative to that in the unstructured rest state, with change maps resembling partially complete maps of the primary sensory cortices and the cognitive control network. The majority of rFC changes occurred in areas moderately (but not weakly) connected to the seeds. Constrained prior states were associated with lower across-participant variance in rFC. This systematic investigation of the effect of prior brain state on rFC indicates that the rFC changes induced by prior brain state occur both in brain networks related to that brain activity and in networks nominally unrelated to that brain activity. PMID:25463462

Tailby, Chris; Masterton, Richard A J; Huang, Jenny Y; Jackson, Graeme D; Abbott, David F

2015-02-01

6

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

PubMed Central

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

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

2012-01-01

7

Isolating human brain functional connectivity associated with a specific cognitive process  

Microsoft Academic Search

The use of functional magnetic resonance imaging (fMRI) to measure functional connectivity among brain areas has the potential to identify neural networks associated with particular cognitive processes. However, fMRI signals are not a direct measure of neural activity but rather represent blood oxygenation level-dependent (BOLD) signals. Correlated BOLD signals between two brain regions are therefore a combination of neural, neurovascular,

Michael A. Silver; Ayelet N. Landau; Thomas Z. Lauritzen; William Prinzmetal; Lynn C. Robertson

2010-01-01

8

Electrical brain stimulation improves cognitive performance by modulating functional connectivity and task-specific activation.  

PubMed

Excitatory anodal transcranial direct current stimulation (atDCS) can improve human cognitive functions, but neural underpinnings of its mode of action remain elusive. In a cross-over placebo ("sham") controlled study we used functional magnetic resonance imaging (fMRI) to investigate neurofunctional correlates of improved language functions induced by atDCS over a core language area, the left inferior frontal gyrus (IFG). Intrascanner transcranial direct current stimulation-induced changes in overt semantic word generation assessed behavioral modulation; task-related and task-independent (resting-state) fMRI characterized language network changes. Improved word-retrieval during atDCS was paralleled by selectively reduced task-related activation in the left ventral IFG, an area specifically implicated in semantic retrieval processes. Under atDCS, resting-state fMRI revealed increased connectivity of the left IFG and additional major hubs overlapping with the language network. In conclusion, atDCS modulates endogenous low-frequency oscillations in a distributed set of functionally connected brain areas, possibly inducing more efficient processing in critical task-relevant areas and improved behavioral performance. PMID:22302824

Meinzer, Marcus; Antonenko, Daria; Lindenberg, Robert; Hetzer, Stefan; Ulm, Lena; Avirame, Keren; Flaisch, Tobias; Flöel, Agnes

2012-02-01

9

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

PubMed Central

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

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

2006-01-01

10

Search for Patterns of Functional Specificity in the Brain: A Nonparametric Hierarchical Bayesian Model for Group fMRI Data  

PubMed Central

Functional MRI studies have uncovered a number of brain areas that demonstrate highly specific functional patterns. In the case of visual object recognition, small, focal regions have been characterized with selectivity for visual categories such as human faces. In this paper, we develop an algorithm that automatically learns patterns of functional specificity from fMRI data in a group of subjects. The method does not require spatial alignment of functional images from different subjects. The algorithm is based on a generative model that comprises two main layers. At the lower level, we express the functional brain response to each stimulus as a binary activation variable. At the next level, we define a prior over sets of activation variables in all subjects. We use a Hierarchical Dirichlet Process as the prior in order to learn the patterns of functional specificity shared across the group, which we call functional systems, and estimate the number of these systems. Inference based on our model enables automatic discovery and characterization of dominant and consistent functional systems. We apply the method to data from a visual fMRI study comprised of 69 distinct stimulus images. The discovered system activation profiles correspond to selectivity for a number of image categories such as faces, bodies, and scenes. Among systems found by our method, we identify new areas that are deactivated by face stimuli. In empirical comparisons with perviously proposed exploratory methods, our results appear superior in capturing the structure in the space of visual categories of stimuli. PMID:21884803

Sridharan, Ramesh; Vul, Edward; Hsieh, Po-Jang; Kanwisher, Nancy; Golland, Polina

2012-01-01

11

Involvement of specific macrophage-lineage cells surrounding arterioles in barrier and scavenger function in brain cortex.  

PubMed Central

The transport of solutes between blood and brain is regulated by a specific barrier. Capillary endothelial cells of brain are known to mediate barrier function and facilitate transport. Here we report that specific cells surrounding arterioles, known as Mato's fluorescent granular perithelial (FGP) cells or perivascular microglial cells, contribute to the barrier function. Immunohistochemical and in situ hybridization studies indicate that, in normal brain cortex, type I and type II macrophage scavenger receptors are expressed only in FGP/perivascular microglial cells, and surface markers of macrophage lineage are also detected on them. These cells mediate the uptake of macromolecules, including modified low density lipoprotein, horseradish peroxidase, and ferritin injected either into the blood or into the cerebral ventricles. Accumulation of scavenged materials with aging or after the administration of a high-fat diet results in the formation of honeycomb-like foam cells and the narrowing of the lumen of arterioles in the brain cortex. These results indicate involvement of FGP/perivascular microglial cells in the barrier and scavenger functions in the central nervous system. Images Fig. 1 Fig. 2 Fig. 4 Fig. 5 Fig. 6 PMID:8622926

Mato, M; Ookawara, S; Sakamoto, A; Aikawa, E; Ogawa, T; Mitsuhashi, U; Masuzawa, T; Suzuki, H; Honda, M; Yazaki, Y; Watanabe, E; Luoma, J; Yla-Herttuala, S; Fraser, I; Gordon, S; Kodama, T

1996-01-01

12

Brain imaging and brain function  

SciTech Connect

This book is a survey of the applications of imaging studies of regional cerebral blood flow and metabolism to the investigation of neurological and psychiatric disorders. Contributors review imaging techniques and strategies for measuring regional cerebral blood flow and metabolism, for mapping functional neural systems, and for imaging normal brain functions. They then examine the applications of brain imaging techniques to the study of such neurological and psychiatric disorders as: cerebral ischemia; convulsive disorders; cerebral tumors; Huntington's disease; Alzheimer's disease; depression and other mood disorders. A state-of-the-art report on magnetic resonance imaging of the brain and central nervous system rounds out the book's coverage.

Sokoloff, L.

1985-01-01

13

Human Functional Brain Imaging  

E-print Network

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

Rambaut, Andrew

14

Roles of diverse glutamate receptors in brain functions elucidated by subunit-specific and region-specific gene targeting  

Microsoft Academic Search

Glutamate receptor (GluR) channels play a major role in fast excitatory synaptic transmission in vertebrate central nervous system. We revealed the molecular diversity of the GluR channel by molecular cloning and investigated their physiological roles by subunit-specific gene targeting. NMDA receptor GluR?1 KO mice showed increase in thresholds for hippocampal long-term potentiation and hippocampus–dependent contextual learning. The mutant mice performed

Hisashi Mori; Masayoshi Mishina

2003-01-01

15

COPPER AND BRAIN FUNCTION  

Technology Transfer Automated Retrieval System (TEKTRAN)

Increasing evidence shows that brain development and function are impaired when the brain is deprived of copper either through dietary copper deficiency or through genetic defects in copper transport. A number of copper-dependent enzymes whose activities are lowered by copper deprivation form the ba...

16

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

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

Modulating Brain Oscillations to Drive Brain Function  

PubMed Central

Do neuronal oscillations play a causal role in brain function? In a study in this issue of PLOS Biology, Helfrich and colleagues address this long-standing question by attempting to drive brain oscillations using transcranial electrical current stimulation. Remarkably, they were able to manipulate visual perception by forcing brain oscillations of the left and right visual hemispheres into synchrony using oscillatory currents over both hemispheres. Under this condition, human observers more often perceived an inherently ambiguous visual stimulus in one of its perceptual instantiations. These findings shed light on the mechanisms underlying neuronal computation. They show that it is the neuronal oscillations that drive the visual experience, not the experience driving the oscillations. And they indicate that synchronized oscillatory activity groups brain areas into functional networks. This points to new ways for controlled experimental and possibly also clinical interventions for the study and modulation of brain oscillations and associated functions. PMID:25549340

Thut, Gregor

2014-01-01

19

Cell type-specific spatial and functional coupling between mammalian brain Kv2.1 K+ channels and ryanodine receptors.  

PubMed

The Kv2.1 voltage-gated K+ channel is widely expressed throughout mammalian brain, where it contributes to dynamic activity-dependent regulation of intrinsic neuronal excitability. Here we show that somatic plasma membrane Kv2.1 clusters are juxtaposed to clusters of intracellular ryanodine receptor (RyR) Ca2+ -release channels in mouse brain neurons, most prominently in medium spiny neurons (MSNs) of the striatum. Electron microscopy-immunogold labeling shows that in MSNs, plasma membrane Kv2.1 clusters are adjacent to subsurface cisternae, placing Kv2.1 in close proximity to sites of RyR-mediated Ca2+ release. Immunofluorescence labeling in transgenic mice expressing green fluorescent protein in specific MSN populations reveals the most prominent juxtaposed Kv2.1:RyR clusters in indirect pathway MSNs. Kv2.1 in both direct and indirect pathway MSNs exhibits markedly lower levels of labeling with phosphospecific antibodies directed against the S453, S563, and S603 phosphorylation site compared with levels observed in neocortical neurons, although labeling for Kv2.1 phosphorylation at S563 was significantly lower in indirect pathway MSNs compared with those in the direct pathway. Finally, acute stimulation of RyRs in heterologous cells causes a rapid hyperpolarizing shift in the voltage dependence of activation of Kv2.1, typical of Ca2+ /calcineurin-dependent Kv2.1 dephosphorylation. Together, these studies reveal that striatal MSNs are distinct in their expression of clustered Kv2.1 at plasma membrane sites juxtaposed to intracellular RyRs, as well as in Kv2.1 phosphorylation state. Differences in Kv2.1 expression and phosphorylation between MSNs in direct and indirect pathways provide a cell- and circuit-specific mechanism for coupling intracellular Ca2+ release to phosphorylation-dependent regulation of Kv2.1 to dynamically impact intrinsic excitability. PMID:24962901

Mandikian, Danielle; Bocksteins, Elke; Parajuli, Laxmi Kumar; Bishop, Hannah I; Cerda, Oscar; Shigemoto, Ryuichi; Trimmer, James S

2014-10-15

20

Wavelet analysis for brain-function imaging  

Microsoft Academic Search

The authors present a new algorithmic procedure for the analysis of brain images. This procedure is specifically designed to image the activity and functional organization of the brain. The authors' results are tested on data collected and previously analyzed with the technique known as in vivo optical imaging of intrinsic signals. The authors' procedure enhances the applicability of this technique

R. A. Carmona; Wen L. Hwang; Ron D. Frostig

1995-01-01

21

[Neurosteroid dehydroepiandrosterone and brain function].  

PubMed

For last 30 years it became clear that DHEA and DHEAS are synthesized de novo in brain. Steroids synthesized in brain structures, were received the name "neurosteroids". In the review are submitted data on a biosynthesis and metabolism of DHEA(S) including its metabolism in fatty tissue where it serves as substrate for intracellular formation of its biologically active metabolites--estradiol and testosterone. The role of a sulfatase and sulfotransferase in mutual transformations of DHEA and DHEA-sulfate are analysed. Specific differences in DHEA synthesis in adrenals are surveyed. The adrenals of primates, both human beings and monkeys, produce free DHEA and DHEA-sulphate in large quantity. Their synthesis proceeds on ?5-pathways: cholesterol-pregnenolone-17-hydroxypregnenolone-DHEA. Adrenals of other animas species, including rats and mice, don't synthesize DHEA. From the authors point of view, process of DHEAS penetration in brain structures include two mechanisms: transformation under steroid sulfatase action DHEAS in DHEA which freely gets through a blood-brain barrier and DHEAS passing through a hypothalamus which isn't protected by a blood-brain barrier. Results of researches on clinical application of DHEA as neurosteroid, with the analysis of its role in a course of Alzheimer's disease, distrurbances of cognitive function and other disorders of a CBS are presented also. The main neurobiological effects of DHEA(S) on brain structures which are studied on various models of animals include: neuroprotection, neurogenesis and neuronal survival, apoptosis, catecholamine synthesis and secretion. Neurosteroids have also antioxidant, anti-inflammatory and anti-glucocorticoid effects. PMID:25509179

Goncharov, N P; Katsia, G V

2013-01-01

22

Nova regulates brain-specific splicing to shape the synapse  

Microsoft Academic Search

Alternative RNA splicing greatly increases proteome diversity and may thereby contribute to tissue-specific functions. We carried out genome-wide quantitative analysis of alternative splicing using a custom Affymetrix microarray to assess the role of the neuronal splicing factor Nova in the brain. We used a stringent algorithm to identify 591 exons that were differentially spliced in the brain relative to immune

Jernej Ule; Aljaž Ule; Joanna Spencer; Alan Williams; Jing-Shan Hu; Melissa Cline; Hui Wang; Tyson Clark; Claire Fraser; Matteo Ruggiu; Barry R Zeeberg; David Kane; John N Weinstein; John Blume; Robert B Darnell

2005-01-01

23

Genetic functional inactivation of neuronal nitric oxide synthase affects stress-related Fos expression in specific brain regions  

Microsoft Academic Search

To identify neuronal substrates involved in NO\\/stress interactions we used Fos expression as a marker and examined the pattern of neuronal activation in response to swim stress in nNOS knock-out (nNOS–\\/–) and wild-type (WT) mice. Forced swimming enhanced Fos expression in WT and nNOS–\\/– mice in several brain regions, including cortical, limbic and hypothalamic regions. Differences in the Fos response

P. Salchner; G. Lubec; M. Engelmann; G. F. Orlando; G. Wolf; S. B. Sartori; H. Hoeger; N. Singewald

2004-01-01

24

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

25

Methods for functional brain imaging  

E-print Network

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

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

2011-01-01

26

Brain Structure & Function Structure Function  

E-print Network

, perception of stimuli (e.g. touch, pain, temperature) Temporal lobe Hearing, speech, memory Choroid plexus Learning and memory, spatial orientation Hypothalamus 4Fs (feeding, fleeing, fighting, making love) Lateral (oblongata) Maintaining vital body functions (e.g. breathing, heart beat) Olfactory bulb Sense olfactory

Hull, Elaine

27

Functions of N-Acetyl-l-Aspartate and N-Acetyl-l-Aspartylglutamate in the Vertebrate Brain: Role in Glial Cell-Specific Signaling  

Microsoft Academic Search

N-Acetyl-L-aspartate (NAA) and its derivative N-acetylaspartylglutamate (NAAG) are major osmolytes present in the vertebrate brain. Although they are synthe- sized primarily in neurons, their function in these cells is unclear. In the brain, these substances undergo inter- compartmental cycles in which they are released by neu- rons in a regulated fashion and are then rapidly hydro- lyzed by catabolic enzymes

Morris H. Baslow

2002-01-01

28

Modeling of region-specific fMRI BOLD neurovascular response functions in rat brain reveals residual differences that correlate with the differences in regional evoked potentials  

PubMed Central

The response of the rat visual system to flashes of blue light has been studied by blood oxygen level dependent (BOLD) functional magnetic resonance imaging (fMRI). The BOLD temporal response is dependent on the number of flashes presented and demonstrates a refractory period that depends on flash frequency. Activated brain regions included the primary and secondary visual cortex, superior colliculus (SC), dorsal Lateral Geniculate (DLG), and Lateral Posterior Nucleus (LP), which were found to exhibit differing temporal responses. To explain these differences, the BOLD neurovascular response function was modeled. A second order differential equation was developed and solved numerically to arrive at region-specific response functions. Included in the model are the light input from the diode (duty cycle), a refractory period, a transient response following onset and cessation of stimulus, and a slow adjustment to changes in the average level of the signal. Constants in the differential equation were evaluated for each region by fitting the model to the experimental BOLD response from a single flash, and the equation was then solved for multiple flashes. The simulation mimics the major features of the data; however, remaining differences in the frequency dependence of the response between the cortical and subcortical regions were unexplained. We hypothesized that these discrepancies were due to regional-specific differences in neuronal response to flash frequency. To test this hypothesis, cortical visual evoked potentials (VEPs) were recorded using the same stimulation protocol as the fMRI. Cortical VEPs were more suppressed than subcortical VEPs as flash frequency increased, supporting our hypothesis. This is the first report that regional differences in neuronal activation to the same stimulus lead to differential BOLD activation. PMID:18406628

Pawela, Christopher P.; Hudetz, Anthony G.; Ward, B. Douglas; Schulte, Marie L.; Li, Rupeng; Kao, Dennis S.; Mauck, Matthew C.; Cho, Younghoon R.; Neitz, Jay; Hyde, James S.

2008-01-01

29

[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

30

Regulation of brain function by exercise  

Microsoft Academic Search

The effect of excercise on brain function was investigated through animal experiments. Exercise leads to increased serum calcium levels, and the calcium is transported to the brain. This in turn enhances brain dopamine synthesis through a calmodulin-dependent system, and increased dopamine levels regulate various brain functions. There are abnormally low levels of dopamine in the neostriatum and nucleus accumbens of

Den’etsu Sutoo; Kayo Akiyama

2003-01-01

31

Brief Report: Brain Mechanisms in Autism: Functional and Structural Abnormalities.  

ERIC Educational Resources Information Center

This paper summarizes results of research on functional and structural abnormalities of the brain in autism. The current concept of causation is seen to involve multiple biologic levels. A consistent profile of brain function and dysfunction across methods has been found and specific neuropathologic findings have been found; but some research…

Minshew, Nancy J.

1996-01-01

32

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

Microsoft Academic Search

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

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

33

Functional Imaging: Is the Resting Brain Resting?  

E-print Network

actually rest, idly waiting to process new information from the environment? A number of brain imaging being processed [2]. One approach to visualising the resting brain has been to compare the patternFunctional Imaging: Is the Resting Brain Resting? It is often assumed that the human brain only

Miall, Chris

34

Frequency-specific network topologies in the resting human brain  

PubMed Central

A community is a set of nodes with dense inter-connections, while there are sparse connections between different communities. A hub is a highly connected node with high centrality. It has been shown that both “communities” and “hubs” exist simultaneously in the brain's functional connectivity network (FCN), as estimated by correlations among low-frequency spontaneous fluctuations in functional magnetic resonance imaging (fMRI) signal changes (0.01–0.10 Hz). This indicates that the brain has a spatial organization that promotes both segregation and integration of information. Here, we demonstrate that frequency-specific network topologies that characterize segregation and integration also exist within this frequency range. In investigating the coherence spectrum among 87 brain regions, we found that two frequency bands, 0.01–0.03 Hz (very low frequency [VLF] band) and 0.07–0.09 Hz (low frequency [LF] band), mainly contributed to functional connectivity. Comparing graph theoretical indices for the VLF and LF bands revealed that the network in the former had a higher capacity for information segregation between identified communities than the latter. Hubs in the VLF band were mainly located within the anterior cingulate cortices, whereas those in the LF band were located in the posterior cingulate cortices and thalamus. Thus, depending on the timescale of brain activity, at least two distinct network topologies contributed to information segregation and integration. This suggests that the brain intrinsically has timescale-dependent functional organizations. PMID:25566037

Sasai, Shuntaro; Homae, Fumitaka; Watanabe, Hama; Sasaki, Akihiro T.; Tanabe, Hiroki C.; Sadato, Norihiro; Taga, Gentaro

2014-01-01

35

Functional brain imaging of appetite.  

PubMed

Obesity is a neurobehavioral disorder that results from a combination of overeating and insufficient physical activity. Finely tuned mechanisms exist to match food intake to caloric expenditure. However, faced with abundant inexpensive and calorie-dense foods, many humans (and perhaps most) have a tendency to consume beyond their caloric needs. The brain controls food intake by sensing internal energy-balance signals and external cues of food availability, and by controlling feeding behavior; it is therefore at the centre of the obesity problem. This article reviews the recent use of functional brain imaging in humans to study the neural control of appetite, and how the neural systems involved may cause vulnerability to overeating in the obesogenic environment. PMID:22483361

Dagher, Alain

2012-05-01

36

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. PMID:23573251

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

2013-01-01

37

Aging and Functional Brain Networks  

PubMed Central

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 datasets corresponding to 913 healthy subjects from a public magnetic resonance imaging database using functional connectivity density mapping, 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. PMID:21727896

Tomasi, Dardo; Volkow, Nora D.

2011-01-01

38

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

39

Aging and functional brain networks.  

PubMed

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. PMID:21727896

Tomasi, D; Volkow, N D

2012-05-01

40

Development of auditory-specific brain rhythm in infants.  

PubMed

Human infants rapidly develop their auditory perceptual abilities and acquire culture-specific knowledge in speech and music in the second 6 months of life. In the adult brain, neural rhythm around 10 Hz in the temporal lobes is thought to reflect sound analysis and subsequent cognitive processes such as memory and attention. To study when and how such rhythm emerges in infancy, we examined electroencephalogram (EEG) recordings in infants 4 and 12 months of age during sound stimulation and silence. In the 4-month-olds, the amplitudes of narrowly tuned 4-Hz brain rhythm, recorded from bilateral temporal electrodes, were modulated by sound stimuli. In the 12-month-olds, the sound-induced modulation occurred at faster 6-Hz rhythm at temporofrontal locations. The brain rhythms in the older infants consisted of more complex components, as even evident in individual data. These findings suggest that auditory-specific rhythmic neural activity, which is already established before 6 months of age, involves more speed-efficient long-range neural networks by the age of 12 months when long-term memory for native phoneme representation and for musical rhythmic features is formed. We suggest that maturation of distinct rhythmic components occurs in parallel, and that sensory-specific functions bound to particular thalamo-cortical networks are transferred to newly developed higher-order networks step by step until adult hierarchical neural oscillatory mechanisms are achieved across the whole brain. PMID:21226773

Fujioka, Takako; Mourad, Nasser; Trainor, Laurel J

2011-02-01

41

Brain dynamics promotes function Carlos Lourenco  

E-print Network

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

Lisboa, Universidade Técnica de

42

Imaging genetic influences in human brain function.  

PubMed

The association between genes and brain function using functional brain imaging techniques is an emerging and promising area of research that will help to better characterize the influence of genes on cognition and behavior as well as the link between genetic susceptibility and neuropsychiatric disorders. Neurophysiological imaging provides information regarding the effect of genes on brain function at the level of information processing, and neurochemical imaging provides information on the intrinsic mechanisms on how these genes affect the brain response. In this review, we highlight recent studies that have begun to explore the influence of genetic mutations on brain function with these techniques. The results, even from these few studies, illustrate the potential of these techniques to provide a more sensitive assay than behavioral measures used alone. The results also show that neuroimaging techniques can elucidate the influence of genes on brain function in relatively small sample populations, sometimes even in the absence of significant differences in behavioral measures. PMID:15082331

Mattay, Venkata S; Goldberg, Terry E

2004-04-01

43

Manganese action in brain function  

Microsoft Academic Search

Manganese, an essential trace metal, is supplied to the brain via both the blood–brain and the blood–cerebrospinal fluid barriers. There are some mechanisms in this process and transferrin may be involved in manganese transport into the brain. A large portion of manganese is bound to manganese metalloproteins, especially glutamine synthetase in astrocytes. A portion of manganese probably exists in the

Atsushi Takeda

2003-01-01

44

Brain Functional Network for Chewing of Gum  

Microsoft Academic Search

\\u000a Recent studies showed that gum-chewing induced significant increases in cerebral blood flow and blood-oxygenation level in\\u000a the widespread brain regions. However, little is known about the underlying mechanism of chewing-induced regional interconnection\\u000a and interaction within the brain. In this study, we investigated the human brain functional network during chewing of gum\\u000a by using functional magnetic resonance imaging and complex network

Ming Ke; Hui Shen; Zongtan Zhou; Xiaolin Zhou; Dewen Hu; Xuhui Chen

45

Functional Data Analysis in Brain Imaging Studies  

PubMed Central

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

Tian, Tian Siva

2010-01-01

46

[Calcium signaling and brain functions].  

PubMed

Calcium signaling plays a critical role in various cell types by activation of receptors and Ca2+ channels in response to neurotransmitters, hormones, growth, factors etc. Although a variety of functions of intracellular Ca2+ are reported, Ca2+/calmodulin-dependent protein kinases (CaMK) are involved in their mediation. We have been studying on CaMK I, II, III, IV and K in the dynamic regulation in the cells in relation to functions. In this study, we elucidated the structures of the isoforms of CaMKII subunits with nuclear translocation signal (NTS). NTS is included in the variable domain following the regulatory domain with a sequence of KKRK. The isoforms of CaMK subunits such as alpha B, gamma A, gamma A.B, delta 3 and delta 7 contain NTS in the sequences of the structures. Transfection of the isoforms with NTS into NG108-15 cells stimulated the expression of brain-derived neurotrophic factor in the cytoplasm. Activation of CaMKII and IV and mitogen-activated protein kinase (MAPK) was observed during long-term potentiation (LTP) induction in the CA1 area of hippocampus. The activation of CaMKII was sustained for a long period, whereas that of CaMKIV and MAPK was transient. The results suggest that CaMKII is involved in LTP induction, while CaMKIV and MAPK are rather involved in LTP maintenance. We present and discuss our recent studies on regulation of CaMKs in neuronal functions. PMID:12491766

Miyamoto, E; Fukunaga, K; Takeuchi, Y; Yamamoto, H; Kasahara, J; Liu, Jie

2002-11-01

47

Regulation of brain function by exercise.  

PubMed

The effect of excercise on brain function was investigated through animal experiments. Exercise leads to increased serum calcium levels, and the calcium is transported to the brain. This in turn enhances brain dopamine synthesis through a calmodulin-dependent system, and increased dopamine levels regulate various brain functions. There are abnormally low levels of dopamine in the neostriatum and nucleus accumbens of epileptic mice (El mice strain) and spontaneously hypertensive rats (SHR). The low dopamine levels in those animals were improved following intracerebroventricular administration of calcium chloride. Dopamine levels and blood pressure in SHR were also normalized by exercise. In epileptic El mice, convulsions normalized dopamine levels and physiologic function. These findings suggest that exercise or convulsions affect brain function through calcium/calmodulin-dependent dopamine synthesis. This leads to the possibility that some symptoms of Parkinson's disease or senile dementia might be improved by exercise. PMID:12758062

Sutoo, Den'etsu; Akiyama, Kayo

2003-06-01

48

Energetic cost of brain functional connectivity  

PubMed Central

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

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

2013-01-01

49

[Modern methods of functional tomographic brain imaging for brain function reseaching in norm and pathology].  

PubMed

For many years the modern methods of functional tomographic brain imaging (fMRI and PET) were actively used not only for the research of basic brain functions, but also in clinical practice. In present paper we described the basic characteristics of the signal registered with fMRI and PET, the principles of image reconstruction, as well as the methodological requirements, which are necessary to obtain reliable results. The advantages and limitations of modem tomographic methods of the brain functions investigation are discussed. The need of the complex approach use in brain study is emphasized and methods for the study of functional integration of the brain are suggested. PMID:23659056

Kireev, M V; Zakhs, D V; Korotkov, A D; Medvedev, S V

2013-01-01

50

Functional specifications for mathematical computations  

SciTech Connect

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

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

1991-01-01

51

Simple models of human brain functional networks.  

PubMed

Human brain functional networks are embedded in anatomical space and have topological properties--small-worldness, modularity, fat-tailed degree distributions--that are comparable to many other complex networks. Although a sophisticated set of measures is available to describe the topology of brain networks, the selection pressures that drive their formation remain largely unknown. Here we consider generative models for the probability of a functional connection (an edge) between two cortical regions (nodes) separated by some Euclidean distance in anatomical space. In particular, we propose a model in which the embedded topology of brain networks emerges from two competing factors: a distance penalty based on the cost of maintaining long-range connections; and a topological term that favors links between regions sharing similar input. We show that, together, these two biologically plausible factors are sufficient to capture an impressive range of topological properties of functional brain networks. Model parameters estimated in one set of functional MRI (fMRI) data on normal volunteers provided a good fit to networks estimated in a second independent sample of fMRI data. Furthermore, slightly detuned model parameters also generated a reasonable simulation of the abnormal properties of brain functional networks in people with schizophrenia. We therefore anticipate that many aspects of brain network organization, in health and disease, may be parsimoniously explained by an economical clustering rule for the probability of functional connectivity between different brain areas. PMID:22467830

Vértes, Petra E; Alexander-Bloch, Aaron F; Gogtay, Nitin; Giedd, Jay N; Rapoport, Judith L; Bullmore, Edward T

2012-04-10

52

Dietary Saturated Fatty Acids and Brain Function  

Microsoft Academic Search

The degree to which fatty acids modulate brain function beyond periods of rapid brain growth is poorly understood. Nevertheless, recent evidence suggests that dietary fatty acid composition influences numerous behaviors including body temperature regulation, pain sensitivity, feeding behavior including macronutrient selection, and cognitive performance. Importantly, alterations are observed in the absence of essential fatty acid (EFA) deficiency, beyond periods of

Randall J. Kaplan; Carol E. Greenwood

1998-01-01

53

Project X functional requirements specification  

SciTech Connect

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

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

2011-03-01

54

Astrocytes and Brain Function: Implications for Reproduction  

Microsoft Academic Search

Recent evidence suggests that astrocytes have important neu- roregulatory functions in addition to their classic functions of support and segregation of neurons. These newly revealed functions include regulation of neuron communication, neuro- secretion, and synaptic plasticity. Although these actions occur throughout the brain, this review will focus on astrocyte- neuron interactions in the hypothalamus, particularly with re- spect to their

KRISHNAN M. DHANDAPANI; B. MAHESH; DARRELL W. BRANN

2003-01-01

55

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

PubMed Central

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

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

2008-01-01

56

A PROPOSITIONAL REPRESENTATION MODEL OF ANATOMICAL AND FUNCTIONAL BRAIN DATA  

E-print Network

A PROPOSITIONAL REPRESENTATION MODEL OF ANATOMICAL AND FUNCTIONAL BRAIN DATA Pablo MATURANA as a methodological tool to examine brain network organization, topology and complex dynamics, as well brain data and neuropsychological assessments linked to the functions explored in these assessments

Paris-Sud XI, Université de

57

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

58

Ethical issues of brain functional imaging: reading your mind.  

PubMed

Neuroimaging practice and research are overviewed in this paper through an ethics lens. The main ethical implications in biomedical research concerning functional brain imaging are discussed with the focus on issues related to imaging of personal information and privacy. Specific norms and guidelines will be eventually formed in the future under the umbrella of the new discipline of Neuroethics. PMID:18560092

Karanasiou, Irene S; Biniaris, Christos G; Marsh, Andrew J

2008-01-01

59

Noradrenaline and 5-hydroxytryptamine modulation of brain dopamine function  

PubMed Central

1 Dopamine deficiency in the brain is the prime biochemical deficit in Parkinson's disease, but loss of noradrenaline and 5HT also may contribute. 2 In rats, 5HT-containing neurones originating from the dorsal and median raphe nuclei innervate forebrain dopamine-containing areas so as to impose an inhibitory regulatory tone on dopamine function. However, this interaction between brain dopamine and 5HT-containing neuronal systems is complex, and the effect produced appears dependent on the relative activity of each system. 3. Anatomical evidence for innervation of dopamine-containing brain regions by noradrenaline fibres in the rat is scanty, but functional studies suggest the existence of inputs which facilitate dopamine function. 4 Drug therapy designed to increase or decrease brain 5HT function has had no consistent effect in Parkinson's disease. 5 Manipulation of brain noradrenergic activity in Parkinson's disease had little effect, although the noradrenaline precursor L-threo-DOPS may reduce freezing attacks. 6 Until more specific drug molecules are available the role of brain noradrenergic and 5HT mechanisms in Parkinson's disease remains uncertain. PMID:6337612

Jenner, P.; Sheehy, M.; Marsden, C. D.

1983-01-01

60

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

61

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

62

The Brain Prize 2014: complex human functions.  

PubMed

Giacomo Rizzolatti, Stanislas Dehaene, and Trevor Robbins were recently awarded the 2014 Grete Lundbeck European Brain Research Prize for their 'pioneering research on higher brain mechanisms underpinning such complex human functions as literacy, numeracy, motivated behavior and social cognition, and for their effort to understand cognitive and behavioral disorders'. Why was their work highlighted? Is there anything that links together these seemingly disparate lines of research? PMID:25303794

Grigaityte, Kristina; Iacoboni, Marco

2014-11-01

63

Project X functional requirements specification  

SciTech Connect

Project X is a multi-megawatt proton facility being developed to support a world-leading program in Intensity Frontier physics at Fermilab. The facility is designed to support programs in elementary particle and nuclear physics, with possible applications to nuclear energy research. A Functional Requirements Specification has been developed in order to establish performance criteria for the Project X complex in support of these multiple missions, and to assure that the facility is designed with sufficient upgrade capability to provide U.S. leadership for many decades to come. This paper will briefly review the previously described Functional Requirements, and then discuss their recent evolution.

Holmes, S.D.; Henderson, S.D.; Kephart, R.; Kerby, J.; Kourbanis, I.; Lebedev, V.; Mishra, S.; Nagaitsev, S.; Solyak, N.; Tschirhart, R.; /Fermilab

2012-05-01

64

Progesterone Receptors: Form and Function in Brain  

PubMed Central

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

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

2008-01-01

65

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

PubMed

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

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

2014-09-01

66

The Berlin Brain-Computer Interface: Machine Learning Based Detection of User Specific Brain States  

Microsoft Academic Search

We outline the Berlin Brain-Computer Interface (BBCI), a system which enables us to translate brain signals from movements or movement intentions into control commands. The main contribution of the BBCI, which is a non-invasive EEG-based BCI system, is the use of advanced machine learning techniques that allow to adapt to the specific brain signatures of each user with literally no

Benjamin Blankertz; Guido Dornhege; Steven Lemm; Matthias Krauledat; Gabriel Curio; Klaus-robert Müller

2006-01-01

67

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

ERIC Educational Resources Information Center

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

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

2009-01-01

68

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

PubMed Central

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

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

2011-01-01

69

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

E-print Network

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

Mueller, Klaus

70

Avoiding specific region of brain during whole-brain radiotherapy prevents memory loss  

Cancer.gov

Limiting the amount of radiation absorbed in the hippocampal portion of the brain during whole-brain radiotherapy (WBRT) for brain metastases preserves memory function in patients for up to six months after treatment, according to research presented at the American Society for Radiation Oncology's (ASTRO's) 55th Annual Meeting by researchers from the University of Wisconsin School of Medicine and Public Health, home of the UW Paul P. Carbone Comprehensive Cancer Center.

71

Integrating Retinoic Acid Signaling with Brain Function  

ERIC Educational Resources Information Center

The vitamin A derivative retinoic acid (RA) regulates the transcription of about a 6th of the human genome. Compelling evidence indicates a role of RA in cognitive activities, but its integration with the molecular mechanisms of higher brain functions is not known. Here we describe the properties of RA signaling in the mouse, which point to…

Luo, Tuanlian; Wagner, Elisabeth; Drager, Ursula C.

2009-01-01

72

Integrating Retinoic Acid Signaling With Brain Function  

Microsoft Academic Search

The vitamin A derivative retinoic acid (RA) regulates the transcription of about a 6th of the human genome. Compelling evidence indicates a role of RA in cognitive activities, but its integration with the molecular mechanisms of higher brain functions is not known. Here we describe the properties of RA signaling in the mouse, which point to unknown means through which

Tuanlian Luo; Elisabeth Wagner; Ursula C. Dräger

2009-01-01

73

Understanding of Brain Function Multivariate Pattern Analysis  

E-print Network

of multivariate pattern analysis techniques to fMRI datasets is in- troduced. PyMVPA makes use of Python's ability goals of functional brain imaging. Standard univariate fMRI analysis methods, which correlate cognitive analyses of fMRI data. This in turn prevents the adoption of these methods by a large number of research

Bucci, David J.

74

The Role of Sleep in Emotional Brain Function  

PubMed Central

Rapidly emerging evidence continues to describe an intimate and causal relationship between sleep and emotional brain function. These findings are mirrored by longstanding clinical observations demonstrating that nearly all mood and anxiety disorders co-occur with one or more sleep abnormalities. This review aims to (1) provide a synthesis of recent findings describing the emotional brain and behavioral benefits triggered by sleep, and conversely, the detrimental impairments following a lack of sleep, (2) outline a proposed framework in which sleep, and specifically rapid-eye movement (REM) sleep, supports a process of affective brain homeostasis, optimally preparing the organism for next-day social and emotional functioning, and (3) describe how this hypothesized framework can explain the prevalent relationships between sleep and psychiatric disorders, with a particular focus on post-traumatic stress disorder and major depression. PMID:24499013

Goldstein, Andrea N.; Walker, Matthew P.

2014-01-01

75

28 CFR 0.76 - Specific functions.  

Code of Federal Regulations, 2010 CFR

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

2010-07-01

76

Structure and function of complex brain networks  

PubMed Central

An increasing number of theoretical and empirical studies approach the function of the human brain from a network perspective. The analysis of brain networks is made feasible by the development of new imaging acquisition methods as well as new tools from graph theory and dynamical systems. This review surveys some of these methodological advances and summarizes recent findings on the architecture of structural and functional brain networks. Studies of the structural connectome reveal several modules or network communities that are interlinked by hub regions mediating communication processes between modules. Recent network analyses have shown that network hubs form a densely linked collective called a “rich club,” centrally positioned for attracting and dispersing signal traffic. In parallel, recordings of resting and task-evoked neural activity have revealed distinct resting-state networks that contribute to functions in distinct cognitive domains. Network methods are increasingly applied in a clinical context, and their promise for elucidating neural substrates of brain and mental disorders is discussed. PMID:24174898

Sporns, Olaf

2013-01-01

77

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

PubMed Central

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

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

2012-01-01

78

Electromagnetic inverse applications for functional brain imaging  

SciTech Connect

This is the final report of a one-year, Laboratory Directed Research and Development (LDRD) project at Los Alamos National Laboratory (LANL). This project addresses an important mathematical and computational problem in functional brain imaging, namely the electromagnetic {open_quotes}inverse problem.{close_quotes} Electromagnetic brain imaging techniques, magnetoencephalography (MEG) and electroencephalography (EEG), are based on measurements of electrical potentials and magnetic fields at hundreds of locations outside the human head. The inverse problem is the estimation of the locations, magnitudes, and time-sources of electrical currents in the brain from surface measurements. This project extends recent progress on the inverse problem by combining the use of anatomical constraints derived from magnetic resonance imaging (MRI) with Bayesian and other novel algorithmic approaches. The results suggest that we can achieve significant improvements in the accuracy and robustness of inverse solutions by these two approaches.

Wood, C.C.

1997-10-01

79

Homological scaffolds of brain functional networks  

PubMed Central

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

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

2014-01-01

80

Sustained deep-tissue pain alters functional brain connectivity Jieun Kim a,  

E-print Network

Sustained deep-tissue pain alters functional brain connectivity Jieun Kim a, , Marco L. Loggia a connec- tivity change to more clinically relevant sustained deep-tissue pain. Connectivity in specific connectivity a b s t r a c t Recent functional brain connectivity studies have contributed to our understanding

Napadow, Vitaly

81

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

82

Individual diversity of functional brain network economy.  

PubMed

On average, brain network economy represents a trade-off between communication efficiency, robustness and connection cost, though, an analogous understanding on an individual level is largely missing. Evaluating resting-state networks of 42 healthy participants with 7 Tesla functional MRI and graph theory revealed that not even half of all possible connections were common across subjects. The strongest similarities among individuals were observed for interhemispheric and/or short-range connections, which may relate to the essential feature of the human brain to develop specialized systems within each hemisphere. Despite this marked variability in individual network architecture, all subjects exhibited equal small-world properties. Furthermore, interdependency between four major network economy metrics was observed across healthy individuals. The characteristic path length was associated with the clustering coefficient (r=0.93), the response to network attacks (peak correlation r=-0.97) and the physical connection cost in 3D space (r=-0.62). On the other hand, clustering was negatively related to attack response (r=-0.75) and connection cost (r=-0.59). Finally, increased connection cost was associated with better response to attacks (r=0.65). This indicates that functional brain networks with high global information transfer also exhibit strong network resilience. However, it seems that these advantages come at the cost of decreased local communication efficiency and increased physical connection cost. Except for wiring length, the results were replicated on a subsample at 3 Tesla (n=20). These findings highlight the finely tuned interrelationships between different parameters of brain network economy. Moreover, the understanding of the individual diversity of functional brain network economy may provide further insights in the vulnerability to mental and neurological disorders. PMID:25411715

Hahn, Andreas; Kranz, Georg S; Sladky, Ronald; Ganger, Sebastian; Windischberger, Christian; Kasper, Siegfried; Lanzenberger, Rupert

2014-11-20

83

The formation and function of the brain ventricular system  

E-print Network

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

Chang, Jessica T. (Jessica Tzung-Min)

2012-01-01

84

Social Functioning in Children with Brain Insult  

PubMed Central

Social dysfunction is commonly reported by survivors of brain insult, and is often rated as the most debilitating of all sequelae, impacting on many areas of daily life, as well as overall quality of life. Within the early brain insult (EBI) literature, physical and cognitive domains have been of primary interest and social skills have received scant attention. As a result it remains unclear how common these problems are, and whether factors predictive of recovery (insult severity, lesion location, age at insult, environment) in other functional domains (motor, speech, cognition) also contribute to social outcome. This study compared social outcomes for children sustaining EBI at different times from gestation to late childhood to determine whether EBI was associated with an increased risk of problems. Children with focal brain insults were categorized according to timing of brain insult: (i) Congenital (n?=?38): EBI: first–second trimester; (ii) Perinatal (n?=?33); EBI: third trimester to 1-month post-natal; (iii) Infancy (n?=?23): EBI: 2?months–2?years post-birth; (iv) Preschool (n?=?19): EBI: 3–6?years; (v) Middle Childhood (n?=?31): EBI: 7–9?years; and (vi) Late Childhood (n?=?19): EBI: after age 10. Children's teachers completed questionnaires measuring social function (Strengths and Difficulties Questionnaire, Walker–McConnell Scale of Social Competence and School Adjustment). Results showed that children with EBI were at increased risk for social impairment compared to normative expectations. EBI before age 2?years was associated with most significant social impairment, while children with EBI in the preschool years and in late childhood recorded scores closer to normal. Lesion location and laterality were not predictive of social outcome, and nor was social risk. In contrast, presence of disability (seizures) and family function were shown to contribute to aspects of social function. PMID:20631858

Greenham, Mardee; Spencer-Smith, Megan M.; Anderson, Peter J.; Coleman, Lee; Anderson, Vicki A.

2009-01-01

85

Social functioning in children with brain insult.  

PubMed

Social dysfunction is commonly reported by survivors of brain insult, and is often rated as the most debilitating of all sequelae, impacting on many areas of daily life, as well as overall quality of life. Within the early brain insult (EBI) literature, physical and cognitive domains have been of primary interest and social skills have received scant attention. As a result it remains unclear how common these problems are, and whether factors predictive of recovery (insult severity, lesion location, age at insult, environment) in other functional domains (motor, speech, cognition) also contribute to social outcome. This study compared social outcomes for children sustaining EBI at different times from gestation to late childhood to determine whether EBI was associated with an increased risk of problems. Children with focal brain insults were categorized according to timing of brain insult: (i) Congenital (n = 38): EBI: first-second trimester; (ii) Perinatal (n = 33); EBI: third trimester to 1-month post-natal; (iii) Infancy (n = 23): EBI: 2 months-2 years post-birth; (iv) Preschool (n = 19): EBI: 3-6 years; (v) Middle Childhood (n = 31): EBI: 7-9 years; and (vi) Late Childhood (n = 19): EBI: after age 10. Children's teachers completed questionnaires measuring social function (Strengths and Difficulties Questionnaire, Walker-McConnell Scale of Social Competence and School Adjustment). Results showed that children with EBI were at increased risk for social impairment compared to normative expectations. EBI before age 2 years was associated with most significant social impairment, while children with EBI in the preschool years and in late childhood recorded scores closer to normal. Lesion location and laterality were not predictive of social outcome, and nor was social risk. In contrast, presence of disability (seizures) and family function were shown to contribute to aspects of social function. PMID:20631858

Greenham, Mardee; Spencer-Smith, Megan M; Anderson, Peter J; Coleman, Lee; Anderson, Vicki A

2010-01-01

86

Scale-Free Brain Functional Networks Victor M. Eguiluz,1  

E-print Network

Scale-Free Brain Functional Networks Victor M. Egui´luz,1 Dante R. Chialvo,2 Guillermo A. Cecchi,3 is used to extract functional networks connecting correlated human brain sites. Analysis of the resulting-world networks, reflect important functional information about brain states. DOI: 10.1103/PhysRevLett.94

Oro, Daniel

87

When “altering brain function” becomes “mind control”  

PubMed Central

Functional neurosurgery has seen a resurgence of interest in surgical treatments for psychiatric illness. Deep brain stimulation (DBS) technology is the preferred tool in the current wave of clinical experiments because it allows clinicians to directly alter the functions of targeted brain regions, in a reversible manner, with the intent of correcting diseases of the mind, such as depression, addiction, anorexia nervosa, dementia, and obsessive compulsive disorder. These promising treatments raise a critical philosophical and humanitarian question. “Under what conditions does ‘altering brain function’ qualify as ‘mind control’?” In order to answer this question one needs a definition of mind control. To this end, we reviewed the relevant philosophical, ethical, and neurosurgical literature in order to create a set of criteria for what constitutes mind control in the context of DBS. We also outline clinical implications of these criteria. Finally, we demonstrate the relevance of the proposed criteria by focusing especially on serendipitous treatments involving DBS, i.e., cases in which an unintended therapeutic benefit occurred. These cases highlight the importance of gaining the consent of the subject for the new therapy in order to avoid committing an act of mind control. PMID:25352789

Koivuniemi, Andrew; Otto, Kevin

2014-01-01

88

Perinatal Choline Influences Brain Structure and Function  

PubMed Central

Choline is derived not only from the diet, but also from de novo synthesis. It is important for methyl-group metabolism, the formation of membranes, kidney function, and neurotransmission. When deprived of dietary choline, most adult men and postmenopausal women develop signs of organ dysfunction (fatty liver or muscle damage) and have a decreased capacity to convert homocysteine to methionine. Choline is critical during fetal development, when it influences stem cell proliferation and apoptosis, thereby altering brain structure and function (memory is permanently enhanced in rodents exposed to choline during the latter part of gestation). PMID:16673755

Zeisel, Steven H.; Niculescu, Mihai D.

2008-01-01

89

Extracellular K+ specifically modulates a rat brain K+ channel.  

PubMed Central

Extracellular potassium concentration is actively maintained within narrow limits in all higher organisms. Slight variations in extracellular potassium levels can induce major alterations of essential physiological functions in excitable tissues. Here we describe that superfusion of cultured rat hippocampal neurones with potassium-free medium leads to a decrease of a specific outward potassium current, probably carried by RCK4-type channels (RCK4 are potassium channels found in rat brain). This is confirmed by heterologous expression of these channels in Xenopus oocytes. In this system, variations of extracellular potassium in the physiological concentration range induce significant differences in current amplitude. Moreover, the current is completely suppressed in the absence of extracellular potassium. The potassium dependence of macroscopic conductance in RCK4 channels was related by site-directed mutagenesis to that lysine residue in the extracellular loop between the transmembrane segments S5 and S6 of RCK4 protein that confers resistance to extracellular blockage by tetraethylammonium. It is shown that extracellular potassium affects the number of available RCK4 channels, but not the single-channel conductance, the mean open time, or the gating charge displacement upon depolarization. PMID:1549610

Pardo, L A; Heinemann, S H; Terlau, H; Ludewig, U; Lorra, C; Pongs, O; Stühmer, W

1992-01-01

90

Transgenerational epigenetic effects on brain functions.  

PubMed

Psychiatric diseases are multifaceted disorders with complex etiology, recognized to have strong heritable components. Despite intense research efforts, genetic loci that substantially account for disease heritability have not yet been identified. Over the last several years, epigenetic processes have emerged as important factors for many brain diseases, and the discovery of epigenetic processes in germ cells has raised the possibility that they may contribute to disease heritability and disease risk. This review examines epigenetic mechanisms in complex diseases and summarizes the most illustrative examples of transgenerational epigenetic inheritance in mammals and their relevance for brain function. Environmental factors that can affect molecular processes and behavior in exposed individuals and their offspring, and their potential epigenetic underpinnings, are described. Possible routes and mechanisms of transgenerational transmission are proposed, and the major questions and challenges raised by this emerging field of research are considered. PMID:23062885

Bohacek, Johannes; Gapp, Katharina; Saab, Bechara J; Mansuy, Isabelle M

2013-02-15

91

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. PMID:20522267

2010-01-01

92

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

PubMed Central

Background Acupuncture in humans can produce clinical effects via the central nervous system. However, the neural substrates of acupuncture’s effects remain largely unknown. Results We utilized functional MRI to investigate the topological efficiency of brain functional networks in eighteen healthy young adults who were scanned before and after acupuncture at the ST36 acupoints (ACUP) and its sham point (SHAM). Whole-brain functional networks were constructed by thresholding temporal correlations matrices of ninety brain regions, followed by a graph theory-based analysis. We showed that brain functional networks exhibited small-world attributes (high local and global efficiency) regardless of the order of acupuncture and stimulus points, a finding compatible with previous studies of brain functional networks. Furthermore, the brain networks had increased local efficiency after ACUP stimulation but there were no significant differences after SHAM, indicating a specificity of acupuncture point in coordinating local information flow over the whole brain. Moreover, significant (P<0.05, corrected by false discovery rate approach) effects of only acupuncture point were detected on nodal degree of the left hippocampus (higher nodal degree at ACUP as compared to SHAM). Using an uncorrected P<0.05, point-related effects were also observed in the anterior cingulate cortex, frontal and occipital regions while stimulation-related effects in various brain regions of frontal, parietal and occipital cortex regions. In addition, we found that several limbic and subcortical brain regions exhibited point- and stimulation-related alterations in their regional homogeneity (P<0.05, uncorrected). Conclusions Our results suggest that acupuncture modulates topological organization of whole-brain functional brain networks and the modulation has point specificity. These findings provide new insights into neuronal mechanism of acupuncture from the perspective of functional integration. Further studies would be interesting to apply network analysis approaches to study the effects of acupuncture treatments on brain disorders. PMID:22761766

Liu, Xian; Duan, Xiaohui; Shang, Xiaojing; Long, Yu; Chen, Zhiguang; Li, Xiaofang; Huang, Yan; He, Yong

2012-01-01

93

Functional Geometry Alignment and Localization of Brain Areas  

E-print Network

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

Golland, Polina

94

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

NSDL National Science Digital Library

This case study 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. The case was written for an introductory psychology course, but could be adapted for any course that covers brain anatomy, neurological disorders, or rehabilitation therapies.

Omarzu, Julia

2004-01-01

95

Analysis of functional neuronal connectivity in the Drosophila brain  

PubMed Central

Drosophila melanogaster is a valuable model system for the neural basis of complex behavior, but an inability to routinely interrogate physiologic connections within central neural networks of the fly brain remains a fundamental barrier to progress in the field. To address this problem, we have introduced a simple method of measuring functional connectivity based on the independent expression of the mammalian P2X2 purinoreceptor and genetically encoded Ca2+ and cAMP sensors within separate genetically defined subsets of neurons in the adult brain. We show that such independent expression is capable of specifically rendering defined sets of neurons excitable by pulses of bath-applied ATP in a manner compatible with high-resolution Ca2+ and cAMP imaging in putative follower neurons. Furthermore, we establish that this approach is sufficiently sensitive for the detection of excitatory and modulatory connections deep within larval and adult brains. This technically facile approach can now be used in wild-type and mutant genetic backgrounds to address functional connectivity within neuronal networks governing a wide range of complex behaviors in the fly. Furthermore, the effectiveness of this approach in the fly brain suggests that similar methods using appropriate heterologous receptors might be adopted for other widely used model systems. PMID:22539819

Yao, Zepeng; Macara, Ann Marie; Lelito, Katherine R.; Minosyan, Tamara Y.

2012-01-01

96

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

PubMed Central

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

Messé, Arnaud; Caplain, Sophie; Pélégrini-Issac, Mélanie; Blancho, Sophie; Lévy, Richard; Aghakhani, Nozar; Montreuil, Michèle; Benali, Habib; Lehéricy, Stéphane

2013-01-01

97

Violent Video Games Alter Brain Function in Young Men  

MedlinePLUS

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

98

Data-driven analysis of functional brain interactions during free listening to music and speech.  

PubMed

Natural stimulus functional magnetic resonance imaging (N-fMRI) such as fMRI acquired when participants were watching video streams or listening to audio streams has been increasingly used to investigate functional mechanisms of the human brain in recent years. One of the fundamental challenges in functional brain mapping based on N-fMRI is to model the brain's functional responses to continuous, naturalistic and dynamic natural stimuli. To address this challenge, in this paper we present a data-driven approach to exploring functional interactions in the human brain during free listening to music and speech streams. Specifically, we model the brain responses using N-fMRI by measuring the functional interactions on large-scale brain networks with intrinsically established structural correspondence, and perform music and speech classification tasks to guide the systematic identification of consistent and discriminative functional interactions when multiple subjects were listening music and speech in multiple categories. The underlying premise is that the functional interactions derived from N-fMRI data of multiple subjects should exhibit both consistency and discriminability. Our experimental results show that a variety of brain systems including attention, memory, auditory/language, emotion, and action networks are among the most relevant brain systems involved in classic music, pop music and speech differentiation. Our study provides an alternative approach to investigating the human brain's mechanism in comprehension of complex natural music and speech. PMID:24526569

Fang, Jun; Hu, Xintao; Han, Junwei; Jiang, Xi; Zhu, Dajiang; Guo, Lei; Liu, Tianming

2014-02-14

99

The mechanism by which exercise modifies brain function  

Microsoft Academic Search

The effect of exercise on central nervous system function was investigated in relation to the mechanism of calcium-calmodulin-dependent dopamine synthesis in the brain. It is shown here through animal experiments that exercise leads to an increase in the calcium level in the brain. This in turn enhances brain dopamine synthesis, and through this increased dopamine modifies and\\/or affects brain function,

Den'etsu Sutoo; Kayo Akiyama

1996-01-01

100

Executive functions and social skills in survivors of pediatric brain tumor  

Microsoft Academic Search

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

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

2012-01-01

101

Human-specific transcriptional networks in the brain  

PubMed Central

Summary Understanding human-specific patterns of brain gene expression and regulation can provide key insights into human brain evolution and speciation. Here, we use next generation sequencing, and Illumina and Affymetrix microarray platforms, to compare the transcriptome of human, chimpanzee, and macaque telencephalon. Our analysis reveals a predominance of genes differentially expressed within human frontal lobe and a striking increase in transcriptional complexity specific to the human lineage in the frontal lobe. In contrast, caudate nucleus gene expression is highly conserved. We also identify gene co-expression signatures related to either neuronal processes or neuropsychiatric diseases, including a human-specific module with CLOCK as its hub gene and another module enriched for neuronal morphological processes and genes co-expressed with FOXP2, a gene important for language evolution. These data demonstrate that transcriptional networks have undergone evolutionary remodeling even within a given brain region, providing a new window through which to view the foundation of uniquely human cognitive capacities. PMID:22920253

Konopka, Genevieve; Friedrich, Tara; Davis-Turak, Jeremy; Winden, Kellen; Oldham, Michael C.; Gao, Fuying; Chen, Leslie; Wang, Guang-Zhong; Luo, Rui; Preuss, Todd M.; Geschwind, Daniel H.

2013-01-01

102

A new algorithm for spatiotemporal analysis of brain functional connectivity.  

PubMed

Specific networks of interacting neuronal assemblies distributed within and across distinct brain regions underlie brain functions. In most cognitive tasks, these interactions are dynamic and take place at the millisecond time scale. Among neuroimaging techniques, magneto/electroencephalography - M/EEG - allows for detection of very short-duration events and offers the single opportunity to follow, in time, the dynamic properties of cognitive processes (sub-millisecond temporal resolution). In this paper, we propose a new algorithm to track the functional brain connectivity dynamics. During a picture naming task, this algorithm aims at segmenting high-resolution EEG signals (hr-EEG) into functional connectivity microstates. The proposed algorithm is based on the K-means clustering of the connectivity graphs obtained from the phase locking value (PLV) method applied on hr-EEG. Results show that the analyzed evoked responses can be divided into six clusters representing distinct networks sequentially involved during the cognitive task, from the picture presentation and recognition to the motor response. PMID:25583381

Mheich, A; Hassan, M; Khalil, M; Berrou, C; Wendling, F

2015-03-15

103

Non-specific Immunostaining by a Rabbit Antibody against Gustducin ? Subunit in Mouse Brain.  

PubMed

Gustducin is a guanosine nucleotide-binding protein functionally coupled with taste receptors and thus originally identified in taste cells of the tongue. Recently, bitter taste receptors and gustducin have been detected in the airways, digestive tracts and brain. The existing studies showing taste receptors and gustducin in the brain were carried out exclusively on frozen sections. In order to avoid the technical shortcomings associated with frozen sectioning, we performed immunofluorescence staining using vibratome-cut sections from mouse brains. Using a rabbit gustducin antibody, we could not detect neurons or astrocytes as reported previously. Rather, we found dense fibers in the nucleus accumbens and periventricular areas. We assumed these staining patterns to be specific after confirmation with conventional negative control staining. For the verification of this finding, we stained gustducin knockout mouse brain and tongue sections with the same rabbit gustducin antibody. Whereas negative staining was confirmed in the tongue, intensive fibers were constantly stained in the brain. Moreover, immunostaining with a goat gustducin antibody could not demonstrate the fibers in the brain tissue. The present study implies a cross immunoreaction that occurs with the rabbit gustducin antibody in mouse brain samples, suggesting that the conventional negative controls may not be sufficient when an immunostaining pattern is to be verified. PMID:25411190

Xiong, Guoxiang; Redding, Kevin; Chen, Bei; Cohen, Akiva S; Cohen, Noam A

2015-02-01

104

Dynamic reconfiguration of human brain functional networks through neurofeedback.  

PubMed

Recent fMRI studies demonstrated that functional connectivity is altered following cognitive tasks (e.g., learning) or due to various neurological disorders. We tested whether real-time fMRI-based neurofeedback can be a tool to voluntarily reconfigure brain network interactions. To disentangle learning-related from regulation-related effects, we first trained participants to voluntarily regulate activity in the auditory cortex (training phase) and subsequently asked participants to exert learned voluntary self-regulation in the absence of feedback (transfer phase without learning). Using independent component analysis (ICA), we found network reconfigurations (increases in functional network connectivity) during the neurofeedback training phase between the auditory target region and (1) the auditory pathway; (2) visual regions related to visual feedback processing; (3) insula related to introspection and self-regulation and (4) working memory and high-level visual attention areas related to cognitive effort. Interestingly, the auditory target region was identified as the hub of the reconfigured functional networks without a-priori assumptions. During the transfer phase, we again found specific functional connectivity reconfiguration between auditory and attention network confirming the specific effect of self-regulation on functional connectivity. Functional connectivity to working memory related networks was no longer altered consistent with the absent demand on working memory. We demonstrate that neurofeedback learning is mediated by widespread changes in functional connectivity. In contrast, applying learned self-regulation involves more limited and specific network changes in an auditory setup intended as a model for tinnitus. Hence, neurofeedback training might be used to promote recovery from neurological disorders that are linked to abnormal patterns of brain connectivity. PMID:23684872

Haller, Sven; Kopel, Rotem; Jhooti, Permi; Haas, Tanja; Scharnowski, Frank; Lovblad, Karl-Olof; Scheffler, Klaus; Van De Ville, Dimitri

2013-11-01

105

Region-specific expression of a K+ channel gene in brain.  

PubMed Central

Northern blot analysis and in situ hybridization studies reveal the highly localized expression in rat brain of transcripts from a gene (KShIIIA) encoding components for voltage-gated K+ channels. KShIIIA expression is particularly prominent throughout the dorsal thalamus. The expression of KShIIIA is compared to that of a closely related gene, here called NGK2-KV4. These two genes encode transcripts that induce currents in Xenopus oocytes that are as of yet indistinguishable, but they show very different patterns of expression in rat brain. NGK2-KV4 transcripts are particularly abundant in the cerebellar cortex, where KShIIIA expression is very weak. These results demonstrate the existence of cell-type-specific K+ channel components and suggest that one reason for the unusually large diversity of K+ channel proteins is the presence of subtypes that participate in specific brain functions. Images PMID:1374908

Rudy, B; Kentros, C; Weiser, M; Fruhling, D; Serodio, P; Vega-Saenz de Miera, E; Ellisman, M H; Pollock, J A; Baker, H

1992-01-01

106

Order and disorder in the brain function.  

PubMed

The interest in studying the brain electrical activity as a function of the development of intelligence has been spurred by the need to understand how the brain responds to environmental information. The description of sleep in mentally retarded children reveals deviant patterns of the EEG-spindles and of the eye movement activity (REM sleep) when compared to normal children. The patterns may be considered as a valuable index of mental function. According to experimental evidence, the distribution of the eye movements of sleep appears either as random or ordered. The latter are altered in the mentally handicapped in whom the appearance out of chaos, of the order which is needed for intelligence and memory to function, is altered. The sleep signs are redundant as from birth. Their pattern is also related to the psychomotor development of the infant. If their distribution remains random, or appears in long uninterrupted sequences of waves as in epilepsy, intelligence does not develop. A similar strategy appears to function in the foetus when nature organizes the structures that will lead to the development of intelligence. The eye movement patterns of sleep change in the pregnant women as a function of term and resemble those of premature babies of a similar gestational age. They also change as a function of the menstrual cycle and more generally as a function of age. The hypothesis that attention is the diurnal equivalent of REM sleep is discussed. Attempts at modelling the eye movement patterns of REM sleep as a function of near zero gravity environments have been made. 1) By means of a Montecarlo simulation using the semi Markov model during the Spacelab 1 flight. 2) With the method of the single and multiple g-phase transition analysis of the strange attractor dimension (d) during parabolic flights. The implication of the latter for the neural processes involved in learning is that the central nervous system can preserve intact, from input to output, over a period of several days, all the information it receives 3) The relation between spindles and eye movements has also been viewed by a quantum approach which is another medium between the information and the way of describing it. PMID:14523349

Quadens, Olga

2003-01-01

107

Modulation of Intercellular Calcium Signaling by Melatonin, in Avian and Mammalian Astrocytes, is Brain Region Specific  

PubMed Central

Calcium waves among glial cells impact many central nervous system functions, including neural integration and brain metabolism. Here, we have characterized the modulatory effects of melatonin, a pineal neurohormone that mediates circadian and seasonal processes, on glial calcium waves derived from different brain regions and species. Diencephalic and telencephalic astrocytes, from both chick and mouse brains, expressed melatonin receptor proteins. Further, using the calcium-sensitive dye Fluo-4, we conducted real-time imaging analyses of calcium waves propagated among mammalian and avian astrocytes. Mouse diencephalic astrocytic calcium waves spread to an area 2-5 fold larger than waves among avian astrocytes and application of 10 nM melatonin caused a 32% increase in the spread of these mammalian calcium waves, similar to the 23% increase observed in chick diencephalic astrocytes. In contrast, melatonin had no effect on calcium waves in either avian or mammalian telencephalic astrocytes. Mouse telencephalic calcium waves radially spread from their initiation site among untreated astrocytes. However, waves meandered among mouse diencephalic astrocytes, taking heterogeneous paths at variable rates of propagation. Brain regional differences in wave propagation were abolished by melatonin, as diencephalic astrocytes acquired more telencephalon-like wave characteristics. Astrocytes cultured from different brain regions, therefore, possess fundamentally disparate mechanisms of calcium wave propagation and responses to melatonin. These results suggest multiple roles for melatonin receptors in the regulation of astroglial function, impacting specific brain regions differentially. PMID:16261532

Peters, Jennifer L.; Earnest, Barbara J.; Tjalkens, Ronald B.; Cassone, Vincent M.; Zoran, Mark J.

2008-01-01

108

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

PubMed Central

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

Franke, Katja; Ristow, Michael; Gaser, Christian

2014-01-01

109

Integrating in vitro organ-specific function with the microcirculation  

PubMed Central

There is significant interest within the tissue engineering and pharmaceutical industries to create 3D microphysiological systems of human organ function. The interest stems from a growing concern that animal models and simple 2D culture systems cannot replicate essential features of human physiology that are critical to predict drug response, or simply to develop new therapeutic strategies to repair or replace damaged organs. Central to human organ function is a microcirculation that not only enhances the rate of nutrient and waste transport by convection, but also provides essential additional physiological functions that can be specific to each organ. This review highlights progress in the creation of in vitro functional microvessel networks, and emphasizes organ-specific functional and structural characteristics that should be considered in the future mimicry of four organ systems that are of primary interest: lung, brain, liver, and muscle (skeletal and cardiac). PMID:24729953

Moya, Monica L.; George, Steven C.

2014-01-01

110

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

111

Evolutionarily novel functional networks in the human brain?  

PubMed

Primate evolution has been accompanied by complex reorganizations in brain anatomy and function. Little is known, however, about the relationship between anatomical and functional changes induced through primate evolution. Using functional magnetic resonance imaging, we assessed spatial and temporal correspondences of cortical networks in humans and monkeys. We provided evidence for topologically and functionally correspondent networks in sensory-motor and attention regions. More specifically, we revealed a possible monkey equivalent of the human ventral attention network. For other human networks, such as the language and the default-mode networks, we detected topological correspondent networks in the monkey, but with different functional signatures. Furthermore, we observed two lateralized human frontoparietal networks in the cortical regions displaying the greatest evolutionary expansion, having neither topological nor functional monkey correspondents. This finding may indicate that these two human networks are evolutionarily novel. Thus, our findings confirm the existence of networks where evolution has conserved both topology and function but also suggest that functions of structurally preserved networks can diverge over time and that novel, hence human-specific networks, have emerged during human evolution. PMID:23426655

Mantini, Dante; Corbetta, Maurizio; Romani, Gian Luca; Orban, Guy A; Vanduffel, Wim

2013-02-20

112

Mapping distributed brain function and networks with diffuse optical tomography.  

PubMed

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

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

2014-06-01

113

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

114

Abnormal structural and functional brain connectivity in gray matter heterotopia  

E-print Network

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

Christodoulou, Joanna

115

Culturing Layer-Specific Neocortical Neurons as a Cell Replacement Therapy Following Traumatic Brain Injury  

PubMed Central

Neurophysiological changes resulting from traumatic brain injury (TBI) can result in adverse changes in behavior including mood instability and cognitive dysfunction. Cell death following TBI likely contributes to these altered behaviors and remains an elusive but attractive target for therapies aiming at functional recovery. Previously we demonstrated that neural progenitor cells derived from embryonic rats can be transplanted into donor neonatal rat brain slices and, over the course of 2?weeks in culture, mature into neurons that express neuronal immunohistochemical markers and develop electrophysiological profiles consistent with excitatory and inhibitory interneurons. Here we examine the potential of generating electrophysiologically mature neurons with a layer-specific phenotype as a next step in developing a therapy designed to rebuild a damaged cortical column with the functionally appropriate neuronal subtypes. Preliminary results suggest that neurons derived from passaged neurospheres and grown in dissociated cell culture develop GABAergic and presumed glutamatergic phenotypes and that the percentage of GABAergic cells increases as a function of passage. After 2?weeks in culture, the neurons have a mix of immature and mature neuronal electrophysiological profiles and receive synaptic inputs from surrounding neurons. Subsets of cells expressing neuron specific markers also express layer-specific markers such as Cux1, ER81, and ROR?. Future studies will investigate the potential of transplanting layer-specific neurons generated and isolated in vitro into the neocortex of neonatal brain slices and their potential to maintain their phenotype and integrate into the host tissue. PMID:24432011

Cramer, Nathan Peter; Chatterjee, Mitali; Lischka, Fritz Walter; Juliano, Sharon L.

2014-01-01

116

Lineage-specific splicing of a brain-enriched alternative exon promotes glioblastoma progression  

PubMed Central

Tissue-specific alternative splicing is critical for the emergence of tissue identity during development, yet the role of this process in malignant transformation is undefined. Tissue-specific splicing involves evolutionarily conserved, alternative exons that represent only a minority of the total alternative exons identified. Many of these conserved exons have functional features that influence signaling pathways to profound biological effect. Here, we determined that lineage-specific splicing of a brain-enriched cassette exon in the membrane-binding tumor suppressor annexin A7 (ANXA7) diminishes endosomal targeting of the EGFR oncoprotein, consequently enhancing EGFR signaling during brain tumor progression. ANXA7 exon splicing was mediated by the ribonucleoprotein PTBP1, which is normally repressed during neuronal development. PTBP1 was highly expressed in glioblastomas due to loss of a brain-enriched microRNA (miR-124) and to PTBP1 amplification. The alternative ANXA7 splicing trait was present in precursor cells, suggesting that glioblastoma cells inherit the trait from a potential tumor-initiating ancestor and that these cells exploit this trait through accumulation of mutations that enhance EGFR signaling. Our data illustrate that lineage-specific splicing of a tissue-regulated alternative exon in a constituent of an oncogenic pathway eliminates tumor suppressor functions and promotes glioblastoma progression. This paradigm may offer a general model as to how tissue-specific regulatory mechanisms can reprogram normal developmental processes into oncogenic ones. PMID:24865424

Ferrarese, Roberto; Harsh, Griffith R.; Yadav, Ajay K.; Bug, Eva; Maticzka, Daniel; Reichardt, Wilfried; Dombrowski, Stephen M.; Miller, Tyler E.; Masilamani, Anie P.; Dai, Fangping; Kim, Hyunsoo; Hadler, Michael; Scholtens, Denise M.; Yu, Irene L.Y.; Beck, Jürgen; Srinivasasainagendra, Vinodh; Costa, Fabrizio; Baxan, Nicoleta; Pfeifer, Dietmar; von Elverfeldt, Dominik; Backofen, Rolf; Weyerbrock, Astrid; Duarte, Christine W.; He, Xiaolin; Prinz, Marco; Chandler, James P.; Vogel, Hannes; Chakravarti, Arnab; Rich, Jeremy N.; Carro, Maria S.; Bredel, Markus

2014-01-01

117

Lineage-specific splicing of a brain-enriched alternative exon promotes glioblastoma progression.  

PubMed

Tissue-specific alternative splicing is critical for the emergence of tissue identity during development, yet the role of this process in malignant transformation is undefined. Tissue-specific splicing involves evolutionarily conserved, alternative exons that represent only a minority of the total alternative exons identified. Many of these conserved exons have functional features that influence signaling pathways to profound biological effect. Here, we determined that lineage-specific splicing of a brain-enriched cassette exon in the membrane-binding tumor suppressor annexin A7 (ANXA7) diminishes endosomal targeting of the EGFR oncoprotein, consequently enhancing EGFR signaling during brain tumor progression. ANXA7 exon splicing was mediated by the ribonucleoprotein PTBP1, which is normally repressed during neuronal development. PTBP1 was highly expressed in glioblastomas due to loss of a brain-enriched microRNA (miR-124) and to PTBP1 amplification. The alternative ANXA7 splicing trait was present in precursor cells, suggesting that glioblastoma cells inherit the trait from a potential tumor-initiating ancestor and that these cells exploit this trait through accumulation of mutations that enhance EGFR signaling. Our data illustrate that lineage-specific splicing of a tissue-regulated alternative exon in a constituent of an oncogenic pathway eliminates tumor suppressor functions and promotes glioblastoma progression. This paradigm may offer a general model as to how tissue-specific regulatory mechanisms can reprogram normal developmental processes into oncogenic ones. PMID:24865424

Ferrarese, Roberto; Harsh, Griffith R; Yadav, Ajay K; Bug, Eva; Maticzka, Daniel; Reichardt, Wilfried; Dombrowski, Stephen M; Miller, Tyler E; Masilamani, Anie P; Dai, Fangping; Kim, Hyunsoo; Hadler, Michael; Scholtens, Denise M; Yu, Irene L Y; Beck, Jürgen; Srinivasasainagendra, Vinodh; Costa, Fabrizio; Baxan, Nicoleta; Pfeifer, Dietmar; von Elverfeldt, Dominik; Backofen, Rolf; Weyerbrock, Astrid; Duarte, Christine W; He, Xiaolin; Prinz, Marco; Chandler, James P; Vogel, Hannes; Chakravarti, Arnab; Rich, Jeremy N; Carro, Maria S; Bredel, Markus

2014-07-01

118

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

119

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

Microsoft Academic Search

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

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

2012-01-01

120

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

121

[Acceptor of action results as a structural functional basis of dynamic stereotype activities of the brain].  

PubMed

The system mechanisms of brain dynamic stereotypes formation are considered. The brain dynamic stereotypes are shown to be formed on the structures of acceptor of action results by dominating motivations and reinforcements. Acceptors of action results are widely spread in brain structures. They are presented in functional systems which form behavioral acts of animals with spreading neural excitations in collaterals of axons of pyramidal tract. Reinforcing excitations form specific architectonic of acceptors of action results, which include brain structures corresponding to modalities of parameters of reinforcements. Dominating motivations, which predict future events, excite molecular engrams of action results which were formed by previous reinforcements. PMID:15895870

Sudakov, K V

2005-01-01

122

Imaging structural and functional brain networks in temporal lobe epilepsy  

PubMed Central

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

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

2013-01-01

123

Gut microbial communities modulating brain development and function  

PubMed Central

Mammalian brain development is initiated in utero and internal and external environmental signals can affect this process all the way until adulthood. Recent observations suggest that one such external cue is the indigenous microbiota which has been shown to affect developmental programming of the brain. This may have consequences for brain maturation and function that impact on cognitive functions later in life. This review discusses these recent findings from a developmental perspective. PMID:22743758

Al-Asmakh, Maha; Anuar, Farhana; Zadjali, Fahad; Rafter, Joseph; Pettersson, Sven

2012-01-01

124

Segment-specific requirements for dorsoventral patterning genes during early brain development in Drosophila.  

PubMed

An initial step in the development of the Drosophila central nervous system is the delamination of a stereotype population of neural stem cells (neuroblasts, NBs) from the neuroectoderm. Expression of the columnar genes ventral nervous system defective (vnd), intermediate neuroblasts defective (ind) and muscle segment homeobox (msh) subdivides the truncal neuroectoderm (primordium of the ventral nerve cord) into a ventral, intermediate and dorsal longitudinal domain, and has been shown to play a key role in the formation and/or specification of corresponding NBs. In the procephalic neuroectoderm (pNE, primordium of the brain), expression of columnar genes is highly complex and dynamic, and their functions during brain development are still unknown. We have investigated the role of these genes (with special emphasis on the Nkx2-type homeobox gene vnd) in early embryonic development of the brain. We show at the level of individually identified cells that vnd controls the formation of ventral brain NBs and is required, and to some extent sufficient, for the specification of ventral and intermediate pNE and deriving NBs. However, we uncovered significant differences in the expression of and regulatory interactions between vnd, ind and msh among brain segments, and in comparison to the ventral nerve cord. Whereas in the trunk Vnd negatively regulates ind, Vnd does not repress ind (but does repress msh) in the ventral pNE and NBs. Instead, in the deutocerebral region, Vnd is required for the expression of ind. We also show that, in the anterior brain (protocerebrum), normal production of early glial cells is independent from msh and vnd, in contrast to the posterior brain (deuto- and tritocerebrum) and to the ventral nerve cord. PMID:17038517

Urbach, Rolf; Volland, Dagmar; Seibert, Janina; Technau, Gerhard M

2006-11-01

125

Ribosome Profiling Reveals a Cell-Type-Specific Translational Landscape in Brain Tumors  

PubMed Central

Glioma growth is driven by signaling that ultimately regulates protein synthesis. Gliomas are also complex at the cellular level and involve multiple cell types, including transformed and reactive cells in the brain tumor microenvironment. The distinct functions of the various cell types likely lead to different requirements and regulatory paradigms for protein synthesis. Proneural gliomas can arise from transformation of glial progenitors that are driven to proliferate via mitogenic signaling that affects translation. To investigate translational regulation in this system, we developed a RiboTag glioma mouse model that enables cell-type-specific, genome-wide ribosome profiling of tumor tissue. Infecting glial progenitors with Cre-recombinant retrovirus simultaneously activates expression of tagged ribosomes and delivers a tumor-initiating mutation. Remarkably, we find that although genes specific to transformed cells are highly translated, their translation efficiencies are low compared with normal brain. Ribosome positioning reveals sequence-dependent regulation of ribosomal activity in 5?-leaders upstream of annotated start codons, leading to differential translation in glioma compared with normal brain. Additionally, although transformed cells express a proneural signature, untransformed tumor-associated cells, including reactive astrocytes and microglia, express a mesenchymal signature. Finally, we observe the same phenomena in human disease by combining ribosome profiling of human proneural tumor and non-neoplastic brain tissue with computational deconvolution to assess cell-type-specific translational regulation. PMID:25122893

Gonzalez, Christian; Sims, Jennifer S.; Hornstein, Nicholas; Mela, Angeliki; Garcia, Franklin; Lei, Liang; Gass, David A.; Amendolara, Benjamin; Bruce, Jeffrey N.

2014-01-01

126

Structure-function relationships in human brain development  

E-print Network

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

Saygin, Zeynep Mevhibe

2012-01-01

127

Decoding Lifespan Changes of the Human Brain Using Resting-State Functional Connectivity MRI  

PubMed Central

The development of large-scale functional brain networks is a complex, lifelong process that can be investigated using resting-state functional connectivity MRI (rs-fcMRI). In this study, we aimed to decode the developmental dynamics of the whole-brain functional network in seven decades (8–79 years) of the human lifespan. We first used parametric curve fitting to examine linear and nonlinear age effect on the resting human brain, and then combined manifold learning and support vector machine methods to predict individuals' “brain ages” from rs-fcMRI data. We found that age-related changes in interregional functional connectivity exhibited spatially and temporally specific patterns. During brain development from childhood to senescence, functional connections tended to linearly increase in the emotion system and decrease in the sensorimotor system; while quadratic trajectories were observed in functional connections related to higher-order cognitive functions. The complex patterns of age effect on the whole-brain functional network could be effectively represented by a low-dimensional, nonlinear manifold embedded in the functional connectivity space, which uncovered the inherent structure of brain maturation and aging. Regression of manifold coordinates with age further showed that the manifold representation extracted sufficient information from rs-fcMRI data to make prediction about individual brains' functional development levels. Our study not only gives insights into the neural substrates that underlie behavioral and cognitive changes over age, but also provides a possible way to quantitatively describe the typical and atypical developmental progression of human brain function using rs-fcMRI. PMID:22952990

Wang, Lubin; Su, Longfei; Shen, Hui; Hu, Dewen

2012-01-01

128

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

129

Manifold learning on brain functional networks in aging.  

PubMed

We propose a new analysis framework to utilize the full information of brain functional networks for computing the mean of a set of brain functional networks and embedding brain functional networks into a low-dimensional space in which traditional regression and classification analyses can be easily employed. For this, we first represent the brain functional network by a symmetric positive matrix computed using sparse inverse covariance estimation. We then impose a Log-Euclidean Riemannian manifold structure on brain functional networks whose norm gives a convenient and practical way to define a mean. Finally, based on the fact that the computation of linear operations can be done in the tangent space of this Riemannian manifold, we adopt Locally Linear Embedding (LLE) to the Log-Euclidean Riemannian manifold space in order to embed the brain functional networks into a low-dimensional space. We show that the integration of the Log-Euclidean manifold with LLE provides more efficient and succinct representation of the functional network and facilitates regression analysis, such as ridge regression, on the brain functional network to more accurately predict age when compared to that of the Euclidean space of functional networks with LLE. Interestingly, using the Log-Euclidean analysis framework, we demonstrate the integration and segregation of cortical-subcortical networks as well as among the salience, executive, and emotional networks across lifespan. PMID:25476411

Qiu, Anqi; Lee, Annie; Tan, Mingzhen; Chung, Moo K

2015-02-01

130

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

PubMed Central

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

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

2014-01-01

131

Unarmed, tumor-specific monoclonal antibody effectively treats brain tumors  

PubMed Central

The epidermal growth factor receptor (EGFR) is often amplified and rearranged structurally in tumors of the brain, breast, lung, and ovary. The most common mutation, EGFRvIII, is characterized by an in-frame deletion of 801 base pairs, resulting in the generation of a novel tumor-specific epitope at the fusion junction. A murine homologue of the human EGFRvIII mutation was created, and an IgG2a murine mAb, Y10, was generated that recognizes the human and murine equivalents of this tumor-specific antigen. In vitro, Y10 was found to inhibit DNA synthesis and cellular proliferation and to induce autonomous, complement-mediated, and antibodydependent cell-mediated cytotoxicity. Systemic treatment with i.p. Y10 of s.c. B16 melanomas transfected to express stably the murine EGFRvIII led to long-term survival in all mice treated (n = 20; P < 0.001). Similar therapy with i.p. Y10 failed to increase median survival of mice with EGFRvIII-expressing B16 melanomas in the brain; however, treatment with a single intratumoral injection of Y10 increased median survival by an average 286%, with 26% long-term survivors (n = 117; P < 0.001). The mechanism of action of Y10 in vivo was shown to be independent of complement, granulocytes, natural killer cells, and T lymphocytes through in vivo complement and cell subset depletions. Treatment with Y10 in Fc receptor knockout mice demonstrated the mechanism of Y10 to be Fc receptor-dependent. These data indicate that an unarmed, tumor-specific mAb may be an effective immunotherapy against human tumors and potentially other pathologic processes in the “immunologically privileged” central nervous system. PMID:10852962

Sampson, John H.; Crotty, Laura E.; Lee, Samson; Archer, Gary E.; Ashley, David M.; Wikstrand, Carol J.; Hale, Laura P.; Small, Clayton; Dranoff, Glenn; Friedman, Allan H.; Friedman, Henry S.; Bigner, Darell D.

2000-01-01

132

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

Microsoft Academic Search

Cognitive dysfunction (affecting particularly attention and working memory) occurs early in patients with multiple sclerosis. Previous studies have focused on identifying potentially adaptive functional reorganization through recruitment of new brain regions that could limit expression of these deficits. However, lesion studies remind us that functional specializations in the brain make certain brain regions necessary for a given task. We therefore

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

2006-01-01

133

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

PubMed Central

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

2014-01-01

134

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

PubMed Central

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

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

2013-01-01

135

The histone H1 family: specific members, specific functions?  

PubMed

The linker histone H1 binds to the DNA entering and exiting the nucleosomal core particle and has an important role in establishing and maintaining higher order chromatin structures. H1 forms a complex family of related proteins with distinct species, tissue and developmental specificity. In higher eukaryotes all H1 variants have the same general structure, consisting of a central conserved globular domain and less conserved N-terminal and C-terminal tails. These tails are moderately conserved among species, but differ among variants, suggesting a specific function for each H1 variant. Due to compensatory mechanisms and to the lack of proper tools, it has been very difficult to study the biological role of individual variants in chromatin-mediated processes. Our knowledge about H1 variants is indeed limited, and in vitro and in vivo observations have often been contradictory. Therefore, H1 variants were considered to be functionally redundant. However, recent knockout studies and biochemical analyses in different organisms have revealed exciting new insights into the specificity and mechanisms of actions of the H1 family members. Here, we collect and compare the available literature about H1 variants and discuss possible specific roles that challenge the concept of H1 being a mere structural component of chromatin and a general repressor of transcription. PMID:18208346

Izzo, Annalisa; Kamieniarz, Kinga; Schneider, Robert

2008-04-01

136

Hierarchical organization of brain functional networks during visual tasks  

NASA Astrophysics Data System (ADS)

The functional network of the brain is known to demonstrate modular structure over different hierarchical scales. In this paper, we systematically investigated the hierarchical modular organizations of the brain functional networks that are derived from the extent of phase synchronization among high-resolution EEG time series during a visual task. In particular, we compare the modular structure of the functional network from EEG channels with that of the anatomical parcellation of the brain cortex. Our results show that the modular architectures of brain functional networks correspond well to those from the anatomical structures over different levels of hierarchy. Most importantly, we find that the consistency between the modular structures of the functional network and the anatomical network becomes more pronounced in terms of vision, sensory, vision-temporal, motor cortices during the visual task, which implies that the strong modularity in these areas forms the functional basis for the visual task. The structure-function relationship further reveals that the phase synchronization of EEG time series in the same anatomical group is much stronger than that of EEG time series from different anatomical groups during the task and that the hierarchical organization of functional brain network may be a consequence of functional segmentation of the brain cortex.

Zhuo, Zhao; Cai, Shi-Min; Fu, Zhong-Qian; Zhang, Jie

2011-09-01

137

Functional photoacoustic tomography of animal brains  

E-print Network

This research is primarily focused on laser-based non-invasive photoacoustic tomography of small animal brains. Photoacoustic tomography, a novel imaging modality, was applied to visualize the distribution of optical absorptions in small...

Wang, Xueding

2005-11-01

138

Biochemical and Physiological Processes in Brain Function and Drug Actions  

Microsoft Academic Search

An understanding of the basic elements of neurotransmission in the brain is an important foundation for any consideration of the clinical use and future development of antidepressants. However, attempts to describe the influ- ences of drugs on brain and neuronal function have become increasingly com- plex, and it is now clear that neuronal processes are complex molecular events involving multiple

W. D. Horst

139

Mapping cognitive brain function with modern high-resolution electroencephalography  

Microsoft Academic Search

High temporal resolution is necessary to resolve the rapidly changing patterns of brain activity that underlie mental function. While electroencephalography (EEG) provides temporal resolution in the millisecond range, which would seem to make it an ideal complement to other imaging modalities, traditional EEG technology and practice provides insufficient spatial detail to identify relationships between brain electrical events and structures and

Alan Gevins; Harrison Leong; Michael E. Smith; Jian Le; Robert Du

1995-01-01

140

Correspondence of the brain's functional architecture during activation and rest  

E-print Network

identified. These distinct patterns can be separated from each other from a single resting FMRI dataset ``active'' even when at ``rest.'' brain connectivity BrainMap FMRI functional connectivity resting (FMRI) since it was first noted that, even with the subject at rest, the FMRI time series from one part

Miall, Chris

141

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

PubMed Central

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

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

2013-01-01

142

Affective state-dependent changes in the brain functional network in major depressive disorder.  

PubMed

In major depressive disorder (MDD), as a network-level disease, the pathophysiology would be displayed to a wide extent over the brain. Moreover, the network-wide changes could be dependent on the context of affective processing. In this study, we sought affective state-dependent changes of the brain functional network by applying a graph-theoretical approach to functional magnetic resonance imaging data acquired in 13 patients with MDD and 12 healthy controls who were exposed to video clips inducing the negative, neutral or positive affective state. For each affective condition, a group-wise brain functional network was constructed based on partial correlation of mean activity across subjects between brain areas. Network parameters, global and local efficiencies, were measured from the brain functional network. Compared with controls', patients' brain functional network shifted to the regular network in the topological architecture, showing decreased global efficiency and increased local efficiency, during negative and neutral affective processing. Further, the shift to the regular network in patients was most evident during negative affective processing. MDD is proposed to provoke widespread changes across the whole brain in an affective state-dependent manner, specifically in the negative affective state. PMID:24249787

Park, Chang-hyun; Wang, Sheng-Min; Lee, Hae-Kook; Kweon, Yong-Sil; Lee, Chung Tai; Kim, Ki-Tae; Kim, Young-Joo; Lee, Kyoung-Uk

2014-09-01

143

Functional connectivity of the rodent brain using optical imaging  

NASA Astrophysics Data System (ADS)

The aim of this thesis is to apply functional connectivity in a variety of animal models, using several optical imaging modalities. Even at rest, the brain shows high metabolic activity: the correlation in slow spontaneous fluctuations identifies remotely connected areas of the brain; hence the term "functional connectivity". Ongoing changes in spontaneous activity may provide insight into the neural processing that takes most of the brain metabolic activity, and so may provide a vast source of disease related changes. Brain hemodynamics may be modified during disease and affect resting-state activity. The thesis aims to better understand these changes in functional connectivity due to disease, using functional optical imaging. The optical imaging techniques explored in the first two contributions of this thesis are Optical Imaging of Intrinsic Signals and Laser Speckle Contrast Imaging, together they can estimate the metabolic rate of oxygen consumption, that closely parallels neural activity. They both have adequate spatial and temporal resolution and are well adapted to image the convexity of the mouse cortex. In the last article, a depth-sensitive modality called photoacoustic tomography was used in the newborn rat. Optical coherence tomography and laminar optical tomography were also part of the array of imaging techniques developed and applied in other collaborations. The first article of this work shows the changes in functional connectivity in an acute murine model of epileptiform activity. Homologous correlations are both increased and decreased with a small dependence on seizure duration. These changes suggest a potential decoupling between the hemodynamic parameters in resting-state networks, underlining the importance to investigate epileptic networks with several independent hemodynamic measures. The second study examines a novel murine model of arterial stiffness: the unilateral calcification of the right carotid. Seed-based connectivity analysis showed a decreasing trend of homologous correlation in the motor and cingulate cortices. Graph analyses showed a randomization of the cortex functional networks, suggesting a loss of connectivity, more specifically in the motor cortex ipsilateral to the treated carotid; however these changes are not reflected in differentiated metabolic estimates. Confounds remain due to the fact that carotid rigidification gives rise to neural decline in the hippocampus as well as unilateral alteration of vascular pulsatility; however the results support the need to look at several hemodynamic parameters when imaging the brain after arterial remodeling. The third article of this thesis studies a model of inflammatory injury on the newborn rat. Oxygen saturation and functional connectivity were assessed with photoacoustic tomography. Oxygen saturation was decreased in the site of the lesion and on the cortex ipsilateral to the injury; however this decrease is not fully explained by hypovascularization revealed by histology. Seed-based functional connectivity analysis showed that inter-hemispheric connectivity is not affected by inflammatory injury.

Guevara Codina, Edgar

144

Near to the Brain: Functional Near-Infrared Spectroscopy as a Lightweight Brain Imaging Technique for Visualization  

E-print Network

Near to the Brain: Functional Near-Infrared Spectroscopy as a Lightweight Brain Imaging Technique the use of cumbersome or expensive brain imaging equipment. In recent years, functional near-infrared near-infrared spectroscopy (fNIRS) is an emerging technology for brain imaging being developed

Tomkins, Andrew

145

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

146

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

147

Anomalous brain functional connectivity contributing to poor adaptive behavior in Down syndrome.  

PubMed

Research in Down syndrome has substantially progressed in the understanding of the effect of gene overexpression at the molecular level, but there is a paucity of information on the ultimate consequences on overall brain functional organization. We have assessed the brain functional status in Down syndrome using functional connectivity MRI. Resting-state whole-brain connectivity degree maps were generated in 20 Down syndrome individuals and 20 control subjects to identify sites showing anomalous synchrony with other areas. A subsequent region-of-interest mapping served to detail the anomalies and to assess their potential contribution to poor adaptive behavior. Down syndrome individuals showed higher regional connectivity in a ventral brain system involving the amygdala/anterior temporal region and the ventral aspect of both the anterior cingulate and frontal cortices. By contrast, lower functional connectivity was identified in dorsal executive networks involving dorsal prefrontal and anterior cingulate cortices and posterior insula. Both functional connectivity increases and decreases contributed to account for patient scoring on adaptive behavior related to communication skills. The data overall suggest a distinctive functional organization with system-specific anomalies associated with reduced adaptive efficiency. Opposite effects were identified on distinct frontal and anterior temporal structures and relative sparing of posterior brain areas, which is generally consistent with Down syndrome cognitive profile. Relevantly, measurable connectivity changes, as a marker of the brain functional anomaly, could have a role in the development of therapeutic strategies addressed to improve the quality of life in Down syndrome individuals. PMID:25461715

Pujol, Jesus; Del Hoyo, Laura; Blanco-Hinojo, Laura; de Sola, Susana; Macià, Dídac; Martínez-Vilavella, Gerard; Amor, Marta; Deus, Joan; Rodríguez, Joan; Farré, Magí; Dierssen, Mara; de la Torre, Rafael

2014-10-28

148

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

PubMed Central

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

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

2013-01-01

149

Functional geometry alignment and localization of brain areas  

E-print Network

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

Langs, Georg

150

Neuron-glia networks: integral gear of brain function  

E-print Network

Astrocytes, the most abundant glial cell in the brain, play critical roles in metabolic and homeostatic functions of the Nervous System; however, their participation in coding information and cognitive processes has been ...

Perea, Gertrudis

151

Weighted Functional Brain Network Modeling via Network Filtration  

E-print Network

), 26 autism spectrum disorder (ASD) and 11 pediatric control (PedCon) children ob- tained through Learning #12;Figure 1: Schematic diagram of proposed functional brain network filtration framework using

Chung, Moo K.

152

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

E-print Network

A Patient-Specific Segmentation Framework for Longitudinal MR Images of Traumatic Brain Injury Bo of California, Los Angeles, California. ABSTRACT Traumatic brain injury (TBI) is a major cause of death, Longitudinal analysis 1. INTRODUCTION Traumatic brain injury (TBI) occurs when an external force traumatically

Utah, University of

153

SEGMENTATION OF PATIENT SPECIFIC MEG/EEG SKULL, SCALP, AND BRAIN MODELS FROM MRI  

E-print Network

SEGMENTATION OF PATIENT SPECIFIC MEG/EEG SKULL, SCALP, AND BRAIN MODELS FROM MRI Belma Dogdas California, LA, CA 90089-2564 ABSTRACT We present an automated method for segmenting skull, scalp, and brain and morphology to produce a scalp mask. The brain and scalp masks provide boundaries between which the skull must

Leahy, Richard M.

154

Enzyme Specific Activity in Functionalized Nanoporous Supports  

SciTech Connect

Enzyme specific activity can be increased or decreased to a large extent by changing protein loading density in functionalized nanoporous support, where organophosphorus hydrolase can display a constructive orientation and thus leave a completely open entrance for substrate even at higher protein loading density, but glucose oxidase can not.

Lei, Chenghong; Soares, Thereza A.; Shin, Yongsoon; Liu, Jun; Ackerman, Eric J.

2008-03-26

155

ProductSpecifications Fit. Form. Function.  

E-print Network

ProductSpecifications Fit. Form. Function. More than 30,000 Thermo Scientific Niton analyzers filters that can clog if not maintained. Thermo Scientific Niton FXL Field X-ray Lab The Thermo Scientific. Part of Thermo Fisher Scientific Niton FXL Mining analzyer (top) Niton FXL Consumer Goods/RoHS analyzer

Short, Daniel

156

Efficiency and Cost of Economical Brain Functional Networks  

Microsoft Academic Search

Brain anatomical networks are sparse, complex, and have economical small-world properties. We investigated the efficiency and cost of human brain functional networks measured using functional magnetic resonance imaging (fMRI) in a factorial design: two groups of healthy old (N ¼11; mean age ¼66.5 years) and healthy young (N ¼15; mean age ¼ 24.7 years) volunteers were each scanned twice in

Sophie Achard; Ed Bullmore

2007-01-01

157

Structural and Functional Rich Club Organization of the Brain in Children and Adults  

PubMed Central

Recent studies using Magnetic Resonance Imaging (MRI) have proposed that the brain’s white matter is organized as a rich club, whereby the most highly connected regions of the brain are also highly connected to each other. Here we use both functional and diffusion-weighted MRI in the human brain to investigate whether the rich club phenomena is present with functional connectivity, and how this organization relates to the structural phenomena. We also examine whether rich club regions serve to integrate information between distinct brain systems, and conclude with a brief investigation of the developmental trajectory of rich-club phenomena. In agreement with prior work, both adults and children showed robust structural rich club organization, comprising regions of the superior medial frontal/dACC, medial parietal/PCC, insula, and inferior temporal cortex. We also show that these regions were highly integrated across the brain’s major networks. Functional brain networks were found to have rich club phenomena in a similar spatial layout, but a high level of segregation between systems. While no significant differences between adults and children were found structurally, adults showed significantly greater functional rich club organization. This difference appeared to be driven by a specific set of connections between superior parietal, insula, and supramarginal cortex. In sum, this work highlights the existence of both a structural and functional rich club in adult and child populations with some functional changes over development. It also offers a potential target in examining atypical network organization in common developmental brain disorders, such as ADHD and Autism. PMID:24505468

Grayson, David S.; Ray, Siddharth; Carpenter, Samuel; Iyer, Swathi; Dias, Taciana G. Costa; Stevens, Corinne; Nigg, Joel T.; Fair, Damien A.

2014-01-01

158

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. PMID:24516567

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

159

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

160

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

PubMed Central

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

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

2014-01-01

161

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

PubMed

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

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

2014-01-01

162

Generating Text from Functional Brain Images  

PubMed Central

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

Pereira, Francisco; Detre, Greg; Botvinick, Matthew

2011-01-01

163

Imaging of Brain Function Using SPECT  

Microsoft Academic Search

Single photon emission computed tomography (SPECT) is a technique widely used in nuclear medicine for the imaging of the many organs including the skeleton and heart, as well as for whole body imaging for the detection of tumors. The use of tracers of cerebral perfusion and more recently brain neurotransmitter systems has resulted in the development of a number of

James M. Warwick

2004-01-01

164

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

165

Congenital brain tumors in Japan (ISPN Cooperative Study): specific clinical features in neonates  

Microsoft Academic Search

The authors present specific clinical features of brain tumors occurring in immature brain in comparison with those of older infants and children. Twenty-six neonatal brain tumors, which accounted for 11.3% of 231 brain tumors diagnosed in the 1st year of life collected in a cooperative study in Japan, were analyzed. Although astrocytomas were invariably common tumors in each age group,

S. Oi; T. Kokunai; S. Matsumoto

1990-01-01

166

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

167

Human brain activity with functional NIR optical imager  

NASA Astrophysics Data System (ADS)

In this paper we reviewed the applications of functional near infrared optical imager in human brain activity. Optical imaging results of brain activity, including memory for new association, emotional thinking, mental arithmetic, pattern recognition ' where's Waldo?, occipital cortex in visual stimulation, and motor cortex in finger tapping, are demonstrated. It is shown that the NIR optical method opens up new fields of study of the human population, in adults under conditions of simulated or real stress that may have important effects upon functional performance. It makes practical and affordable for large populations the complex technology of measuring brain function. It is portable and low cost. In cognitive tasks subjects could report orally. The temporal resolution could be millisecond or less in theory. NIR method will have good prospects in exploring human brain secret.

Luo, Qingming

2001-08-01

168

Function-structure associations of the brain: evidence from multimodal connectivity and covariance studies.  

PubMed

Despite significant advances in multimodal imaging techniques and analysis approaches, unimodal studies are still the predominant way to investigate brain changes or group differences, including structural magnetic resonance imaging (sMRI), functional MRI (fMRI), diffusion tensor imaging (DTI) and electroencephalography (EEG). Multimodal brain studies can be used to understand the complex interplay of anatomical, functional and physiological brain alterations or development, and to better comprehend the biological significance of multiple imaging measures. To examine the function-structure associations of the brain in a more comprehensive and integrated manner, we reviewed a number of multimodal studies that combined two or more functional (fMRI and/or EEG) and structural (sMRI and/or DTI) modalities. In this review paper, we specifically focused on multimodal neuroimaging studies on cognition, aging, disease and behavior. We also compared multiple analysis approaches, including univariate and multivariate methods. The possible strengths and limitations of each method are highlighted, which can guide readers when selecting a method based on a given research question. In particular, we believe that multimodal fusion approaches will shed further light on the neuronal mechanisms underlying the major structural and functional pathophysiological features of both the healthy brain (e.g. development) or the diseased brain (e.g. mental illness) and, in the latter case, may provide a more sensitive measure than unimodal imaging for disease classification, e.g. multimodal biomarkers, which potentially can be used to support clinical diagnosis based on neuroimaging techniques. PMID:24084066

Sui, Jing; Huster, Rene; Yu, Qingbao; Segall, Judith M; Calhoun, Vince D

2014-11-15

169

Proteomic analysis and brain-specific systems biology in a rodent model of penetrating ballistic-like brain injury.  

PubMed

Proteomics and systems biology have significantly contributed to biomarker discovery in the field of brain injury. This study utilized 2D-DIGE-PMF-MS as a preliminary screen to detect biomarkers in a rat model of penetrating ballistic-like brain injury (PBBI). Brain-specific systems biology analysis of brain tissue identified 386 proteins having a fold change of more than 2, of which 321 proteins were increased and 65 were decreased 24 h after PBBI compared to sham controls. The majority of upregulated proteins were cytoskeletal (10.5%), nucleic acid binding (9.3%), or kinases (8.9%). Most proteins were involved in protein metabolism (22.7%), signal transduction (20.4%), and development (9.6%). Pathway analysis indicated that these proteins were involved in neurite outgrowth and cell differentiation. Semiquantitative Western blotting of 6, 24, 48, and 72 h after PBBI indicated ubiquitin carboxyl-terminal hydrolase isozyme L1 (a proposed traumatic brain injury biomarker in human clinical trials), tyrosine hydroxylase, and syntaxin-6 were found to be consistently elevated in brain tissue and cerebral spinal fluid after PBBI compared to sham controls. Combining proteomics and brain-specific systems biology can define underlying mechanisms of traumatic brain injury and provide valuable information in biomarker discovery that, in turn, may lead to novel therapeutic targets. PMID:23161467

Boutté, Angela M; Yao, Changping; Kobeissy, Firas; May Lu, Xi-Chun; Zhang, Zhiqun; Wang, Kevin K; Schmid, Kara; Tortella, Frank C; Dave, Jitendra R

2012-12-01

170

Functional Connectivity between Brain Areas Estimated by Analysis of Gamma Waves  

PubMed Central

The goal of this study is to investigate functional connectivity between different brain regions by analyzing the temporal relationship of the maxima of gamma waves recorded in multiple brain areas. Local field potentials were recorded from motor cortex, hippocampus, entorhinal cortex and piriform cortex of rats. Gamma activity was filtered and separated into two bands; high (65–90Hz) and low (30–55Hz) gamma. Maxima for gamma activity waves were detected and functional connectivity between different brain regions was determined using Shannon entropy for perievent histograms for each pair channels. Significant Shannon entropy values were reported as connectivity factors. We defined a connectivity matrix based the connectivity factors between different regions. We found that maxima of low and high frequency gamma occur in strong temporal relationship between some brain areas, indicating the existence of functional connections between these areas. The spatial pattern of functional connections between brain areas was different for slow wave sleep and waking states. However for each behavioral state in the same animal the pattern of functional connections was stable over time within 30 minutes of continuous analysis and over a 5 day period. With the same electrode montage the pattern of functional connectivity varied from one subject to another. Analysis of the temporal relationship of maxima of gamma waves between various brain areas could be a useful tool for investigation of functional connections between these brain areas. This approach could be applied for analysis of functional alterations occurring in these connections during different behavioral tasks and during processes related to learning and memory. The specificity in the connectivity pattern from one subject to another can be explained by the existence of unique functional networks for each subject. PMID:23376499

Kheiri, Farshad; Bragin, Anatol; Engel, Jerome

2013-01-01

171

Functional connectivity between brain areas estimated by analysis of gamma waves.  

PubMed

The goal of this study is to investigate functional connectivity between different brain regions by analyzing the temporal relationship of the maxima of gamma waves recorded in multiple brain areas. Local field potentials were recorded from motor cortex, hippocampus, entorhinal cortex and piriform cortex of rats. Gamma activity was filtered and separated into two bands; high (65-90Hz) and low (30-55Hz) gamma. Maxima for gamma activity waves were detected and functional connectivity between different brain regions was determined using Shannon entropy for perievent histograms for each pair channels. Significant Shannon entropy values were reported as connectivity factors. We defined a connectivity matrix based the connectivity factors between different regions. We found that maxima of low and high frequency gamma occur in strong temporal relationship between some brain areas, indicating the existence of functional connections between these areas. The spatial pattern of functional connections between brain areas was different for slow wave sleep and waking states. However for each behavioral state in the same animal the pattern of functional connections was stable over time within 30min of continuous analysis and over a 5 day period. With the same electrode montage the pattern of functional connectivity varied from one subject to another. Analysis of the temporal relationship of maxima of gamma waves between various brain areas could be a useful tool for investigation of functional connections between these brain areas. This approach could be applied for analysis of functional alterations occurring in these connections during different behavioral tasks and during processes related to learning and memory. The specificity in the connectivity pattern from one subject to another can be explained by the existence of unique functional networks for each subject. PMID:23376499

Kheiri, Farshad; Bragin, Anatol; Engel, Jerome

2013-04-15

172

Risk, adaptation and the functional teenage brain.  

PubMed

Over the last decade, the propensity for young people to take risks has been a particular focus of neuroscientific inquiries into human development. Taking population-level data about teenagers' involvement in drinking, smoking, dangerous driving and unprotected sex as indicative, a consensus has developed about the association between risk-taking and the temporal misalignment in the development of reward-seeking and executive regions of the brain. There are epistemological difficulties in this theory. Risk, the brain, and adolescence are different kinds of objects, and bringing them into the same frame for analysis is not unproblematic. In particular, risk is inextricably contextual and value-driven. The assessment of adolescent behaviour and decision-making as 'sub-optimal', and the implication that the developmental schedule of the teenage brain is dysfunctional, is also reassessed in terms of evolutionary development of the individual, the family and the human community. The paper proposes a view of adolescent development as adaptive, and a focus on young people's capacities in the profile of the needs of the community as a whole. PMID:24468052

Sercombe, Howard

2014-08-01

173

[Regulation, structure and function of brain aquaporin].  

PubMed

Discovery of aquaporin water channel proteins has provided insight into the molecular mechanism of membrane water permeability. In mammalian brain, Aquaporin-4 (AQP4) is the main water channel and is distributed with highest density in the perivascular and subpial astrocyte end-feet. AQP4 is a critical component of an integrated water and potassium homeostasis. Indeed, AQP4 has been implicated in several neurologic conditions, such as brain edema, seizure and even mood disorders. Expression and regulation of AQP4 have been studied to understand the roles of AQP4 in physiological and pathological conditions. Here we discuss about the mechanisms how AQP4 is dynamically regulated at different levels; channel gating, subcellular distribution, phosphorylation, protein-protein interactions and orthogonal array formation. Interestingly, AQP4 has been identified as a target antigen of autoimmune attack in neuromyelitis optica (NMO). We have evaluated putative epitopes on AQP4 for NMO-IgG binding. We have also studied Drosophila Big Brain (Bib), since Bib has high sequence homology to AQP-4, and play an important role for Drosophila neurogenesis. AQP4 may be a potential therapeutic target in several neurologic conditions. Further studies from different aspects are required to develop new drugs against AQP4. PMID:20030210

Masato, Yasui

2009-11-01

174

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

E-print Network

-invasive patient-specific hyperthermia treatment of pediatric brain cancer Matthew J Burfeindt1 , Earl Zastrow1 adjuvant to other treatment modalities for a variety of cancers (e.g., Overgaard et al 1995, Kapp 1996, VanMicrowave beamforming for non-invasive patient-specific hyperthermia treatment of pediatric brain

Sheridan, Jennifer

175

Identification of Injury Specific Proteins in a Cell Culture Model of Traumatic Brain Injury  

PubMed Central

The complicated secondary molecular and cellular mechanisms following traumatic brain injury (TBI) are still not fully understood. In the present study, we have used mass spectrometry to identify injury specific proteins in an in vitro model of TBI. A standardized injury was induced by scalpel cuts through a mixed cell culture of astrocytes, oligodendrocytes and neurons. Twenty-four hours after the injury, cell culture medium and whole-cell fractions were collected for analysis. We found 53 medium proteins and 46 cell fraction proteins that were specifically expressed after injury and the known function of these proteins was elucidated by an extensive literature survey. By using time-lapse microscopy and immunostainings we could link a large proportion of the proteins to specific cellular processes that occur in response to trauma; including cell death, proliferation, lamellipodia formation, axonal regeneration, actin remodeling, migration and inflammation. A high percentage of the proteins uniquely expressed in the medium after injury were actin-related proteins, which normally are situated intracellularly. We show that two of these, ezrin and moesin, are expressed by astrocytes both in the cell culture model and in mouse brain subjected to experimental TBI. Interestingly, we found many inflammation-related proteins, despite the fact that cells were present in the culture. This study contributes with important knowledge about the cellular responses after trauma and identifies several potential cell-specific biomarkers. PMID:23409102

Lööv, Camilla; Shevchenko, Ganna; Geeyarpuram Nadadhur, Aishwarya; Clausen, Fredrik; Hillered, Lars; Wetterhall, Magnus; Erlandsson, Anna

2013-01-01

176

Functional specialization in the human brain estimated by intrinsic hemispheric interaction.  

PubMed

The human brain demonstrates functional specialization, including strong hemispheric asymmetries. Here specialization was explored using fMRI by examining the degree to which brain networks preferentially interact with ipsilateral as opposed to contralateral networks. Preferential within-hemisphere interaction was prominent in the heteromodal association cortices and minimal in the sensorimotor cortices. The frontoparietal control network exhibited strong within-hemisphere interactions but with distinct patterns in each hemisphere. The frontoparietal control network preferentially coupled to the default network and language-related regions in the left hemisphere but to attention networks in the right hemisphere. This arrangement may facilitate control of processing functions that are lateralized. Moreover, the regions most linked to asymmetric specialization also display the highest degree of evolutionary cortical expansion. Functional specialization that emphasizes processing within a hemisphere may allow the expanded hominin brain to minimize between-hemisphere connectivity and distribute domain-specific processing functions. PMID:25209275

Wang, Danhong; Buckner, Randy L; Liu, Hesheng

2014-09-10

177

Fluid intelligence and brain functional organization in aging yoga and meditation practitioners.  

PubMed

Numerous studies have documented the normal age-related decline of neural structure, function, and cognitive performance. Preliminary evidence suggests that meditation may reduce decline in specific cognitive domains and in brain structure. Here we extended this research by investigating the relation between age and fluid intelligence and resting state brain functional network architecture using graph theory, in middle-aged yoga and meditation practitioners, and matched controls. Fluid intelligence declined slower in yoga practitioners and meditators combined than in controls. Resting state functional networks of yoga practitioners and meditators combined were more integrated and more resilient to damage than those of controls. Furthermore, mindfulness was positively correlated with fluid intelligence, resilience, and global network efficiency. These findings reveal the possibility to increase resilience and to slow the decline of fluid intelligence and brain functional architecture and suggest that mindfulness plays a mechanistic role in this preservation. PMID:24795629

Gard, Tim; Taquet, Maxime; Dixit, Rohan; Hölzel, Britta K; de Montjoye, Yves-Alexandre; Brach, Narayan; Salat, David H; Dickerson, Bradford C; Gray, Jeremy R; Lazar, Sara W

2014-01-01

178

Developmental and cell type-specific expression of thyroid hormone transporters in the mouse brain and in primary brain cells.  

PubMed

Cellular thyroid hormone uptake and efflux are mediated by transmembrane transport proteins. One of these, monocarboxylate transporter 8 (MCT8) is mutated in Allan-Herndon-Dudley syndrome, a severe mental retardation associated with abnormal thyroid hormone constellations. Since mice deficient in Mct8 exhibit a milder neurological phenotype than patients, we hypothesized that alternative thyroid hormone transporters may compensate in murine brain cells for the lack of Mct8. Using qPCR, Western Blot, and immunocytochemistry, we investigated the expression of three different thyroid hormone transporters, i.e., Mct8 and L-type amino acid transporters Lat1 and Lat2, in mouse brain. All three thyroid hormone transporters are expressed from corticogenesis and peak around birth. Primary cultures of neurons and astrocytes express Mct8, Lat1, and Lat2. Microglia specifically expresses Mct10 and Slco4a1 in addition to high levels of Lat2 mRNA and protein. As in vivo, a brain microvascular endothelial cell line expressed Mct8 and Lat1. 158N, an oligodendroglial cell line expressed Mct8 protein, consistent with delayed myelination in MCT8-deficient patients. Functional T(3)- and T(4)-transport assays into primary astrocytes showed K(M) values of 4.2 and 3.7 ?M for T(3) and T(4). Pharmacological inhibition of L-type amino acid transporters by BCH and genetic inactivation of Lat2 reduced astrocytic T(3) uptake to the same extent. BSP, a broad spectrum inhibitor, including Mct8, reduced T(3) uptake further suggesting the cooperative activity of several T(3) transporters in astrocytes. PMID:21264952

Braun, Doreen; Kinne, Anita; Bräuer, Anja U; Sapin, Remy; Klein, Marc O; Köhrle, Josef; Wirth, Eva K; Schweizer, Ulrich

2011-03-01

179

MiR-92b and miR-9/9* Are Specifically Expressed in Brain Primary Tumors and Can Be Used to Differentiate Primary from Metastatic Brain Tumors  

PubMed Central

A recurring challenge for brain pathologists is to diagnose whether a brain malignancy is a primary tumor or a metastasis from some other tissue. The accurate diagnosis of brain malignancies is essential for selection of proper treatment. MicroRNAs are a class of small non-coding RNA species that regulate gene expression; many exhibit tissue-specific expression and are misregulated in cancer. Using microRNA expression profiling, we found that hsa-miR-92b and hsa-miR-9/hsa-miR-9* are over-expressed, specifically in brain primary tumors, as compared to primary tumors from other tissues and their metastases to the brain. By considering the expression of only these two microRNAs, it is possible to distinguish between primary and metastatic brain tumors with very high accuracy. These microRNAs thus represent excellent biomarkers for brain primary tumors. Previous reports have found that hsa-miR-92b and hsa-miR-9/hsa-miR-9* are expressed more strongly in developing neurons and brain than in adult brain. Thus, their specific over-expression in brain primary tumors supports a functional role for these microRNAs or a link between neuronal stem cells and brain tumorigenesis. PMID:18624795

Nass, Dvora; Rosenwald, Shai; Meiri, Eti; Gilad, Shlomit; Tabibian-Keissar, Hilla; Schlosberg, Anat; Kuker, Hagit; Sion-Vardy, Netta; Tobar, Ana; Kharenko, Oleg; Sitbon, Einat; Yanai, Gila Lithwick; Elyakim, Eran; Cholakh, Hila; Gibori, Hadas; Spector, Yael; Bentwich, Zvi; Barshack, Iris; Rosenfeld, Nitzan

2009-01-01

180

Rehabilitation of Executive Functioning in Patients with Frontal Lobe Brain Damage with Goal Management Training  

PubMed Central

Executive functioning deficits due to brain disease affecting frontal lobe functions cause significant real-life disability, yet solid evidence in support of executive functioning interventions is lacking. Goal Management Training (GMT), an executive functioning intervention that draws upon theories concerning goal processing and sustained attention, has received empirical support in studies of patients with traumatic brain injury, normal aging, and case studies. GMT promotes a mindful approach to complex real-life tasks that pose problems for patients with executive functioning deficits, with a main goal of periodically stopping ongoing behavior to monitor and adjust goals. In this controlled trial, an expanded version of GMT was compared to an alternative intervention, Brain Health Workshop that was matched to GMT on non-specific characteristics that can affect intervention outcome. Participants included 19 individuals in the chronic phase of recovery from brain disease (predominantly stroke) affecting frontal lobe function. Outcome data indicated specific effects of GMT on the Sustained Attention to Response Task as well as the Tower Test, a visuospatial problem-solving measure that reflected far transfer of training effects. There were no significant effects on self-report questionnaires, likely owing to the complexity of these measures in this heterogeneous patient sample. Overall, these data support the efficacy of GMT in the rehabilitation of executive functioning deficits. PMID:21369362

Levine, Brian; Schweizer, Tom A.; O'Connor, Charlene; Turner, Gary; Gillingham, Susan; Stuss, Donald T.; Manly, Tom; Robertson, Ian H.

2011-01-01

181

Is functional integration of resting state brain networks an unspecific biomarker for working memory performance?  

PubMed

Is there one optimal topology of functional brain networks at rest from which our cognitive performance would profit? Previous studies suggest that functional integration of resting state brain networks is an important biomarker for cognitive performance. However, it is still unknown whether higher network integration is an unspecific predictor for good cognitive performance or, alternatively, whether specific network organization during rest predicts only specific cognitive abilities. Here, we investigated the relationship between network integration at rest and cognitive performance using two tasks that measured different aspects of working memory; one task assessed visual-spatial and the other numerical working memory. Network clustering, modularity and efficiency were computed to capture network integration on different levels of network organization, and to statistically compare their correlations with the performance in each working memory test. The results revealed that each working memory aspect profits from a different resting state topology, and the tests showed significantly different correlations with each of the measures of network integration. While higher global network integration and modularity predicted significantly better performance in visual-spatial working memory, both measures showed no significant correlation with numerical working memory performance. In contrast, numerical working memory was superior in subjects with highly clustered brain networks, predominantly in the intraparietal sulcus, a core brain region of the working memory network. Our findings suggest that a specific balance between local and global functional integration of resting state brain networks facilitates special aspects of cognitive performance. In the context of working memory, while visual-spatial performance is facilitated by globally integrated functional resting state brain networks, numerical working memory profits from increased capacities for local processing, especially in brain regions involved in working memory performance. PMID:25536495

Alavash, Mohsen; Doebler, Philipp; Holling, Heinz; Thiel, Christiane M; Gießing, Carsten

2015-03-01

182

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

183

Drug addiction: Functional neurotoxicity of the brain reward systems  

Microsoft Academic Search

Drug addiction is a chronic relapsing brain disorder characterized by a compulsion to take a drug with loss of control over\\u000a drug intake. The hypothesis under discussion here is that chronic drug use produces long-lasting dysfunctions in neurons associated\\u000a with the brain reward circuitry, and this “functional neurotoxicity” of drugs of abuse leads to vulnerability to relapse and\\u000a continued drug

Friedbert Weiss; George F. Koob

2001-01-01

184

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

Microsoft Academic Search

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

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

2009-01-01

185

Early Bifrontal Brain Injury: Disturbances in Cognitive Function Development  

PubMed Central

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

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

2010-01-01

186

Quantitative Expression Profile of Distinct Functional Regions in the Adult Mouse Brain  

PubMed Central

The adult mammalian brain is composed of distinct regions with specialized roles including regulation of circadian clocks, feeding, sleep/awake, and seasonal rhythms. To find quantitative differences of expression among such various brain regions, we conducted the BrainStars (B*) project, in which we profiled the genome-wide expression of ?50 small brain regions, including sensory centers, and centers for motion, time, memory, fear, and feeding. To avoid confounds from temporal differences in gene expression, we sampled each region every 4 hours for 24 hours, and pooled the samples for DNA-microarray assays. Therefore, we focused on spatial differences in gene expression. We used informatics to identify candidate genes with expression changes showing high or low expression in specific regions. We also identified candidate genes with stable expression across brain regions that can be used as new internal control genes, and ligand-receptor interactions of neurohormones and neurotransmitters. Through these analyses, we found 8,159 multi-state genes, 2,212 regional marker gene candidates for 44 small brain regions, 915 internal control gene candidates, and 23,864 inferred ligand-receptor interactions. We also found that these sets include well-known genes as well as novel candidate genes that might be related to specific functions in brain regions. We used our findings to develop an integrated database (http://brainstars.org/) for exploring genome-wide expression in the adult mouse brain, and have made this database openly accessible. These new resources will help accelerate the functional analysis of the mammalian brain and the elucidation of its regulatory network systems. PMID:21858037

Nagano, Mamoru; Uno, Kenichiro D.; Tsujino, Kaori; Hanashima, Carina; Shigeyoshi, Yasufumi; Ueda, Hiroki R.

2011-01-01

187

Hemodynamic impairment as a stimulus for functional brain reorganization  

Microsoft Academic Search

We used functional magnetic resonance imaging to investigate whether hemispheral hemodynamic impairment can play an independent role in the functional reorganization of motor-related activity in the brain. Fourteen patients with large vessel occlusion but no infarct performed a simple motor task with the hand contralateral to the occluded vessel. Statistical parametric maps of regional activity were generated to compare the

Randolph S Marshall; John W Krakauer; Theresa Matejovsky; Eric Zarahn; Anna Barnes; Ronald M Lazar; Joy Hirsch

2006-01-01

188

Magnetic resonance imaging of brain function and neurochemistry  

Microsoft Academic Search

In the past decade, magnetic resonance imaging (MRI) research has been focused on the acquisition of physiological and biochemical information noninvasively. Probably the most notable accomplishment in this general effort has been the introduction of the MR approaches to map brain function. This capability, often referred to as functional magnetic resonance imaging, or fMRI, is based on the sensitivity of

KAMIL UGURBIL; DAE-SHIK KIM; TIM DUONG; XIAOPING HU; SEIJI OGAWA; ROLF GRUETTER; WEI CHEN; SEONG-GI KIM; XIAO-HUNG ZHU; ESSA YACOUB; PIERRE-FRANCOIS VAN DE MOORTELE; AMIR SHMUEL; JOSEF PFEUFFER; HELLMUT MERKLE; PETER ANDERSEN; GREGOR ADRIANY

2001-01-01

189

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

190

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

PubMed Central

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

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

2014-01-01

191

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. PMID:24834030

Mandonnet, Emmanuel; Duffau, Hugues

2014-01-01

192

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

193

Automated identification of cell-type-specific genes in the mouse brain by image computing of expression patterns  

PubMed Central

Background Differential gene expression patterns in cells of the mammalian brain result in the morphological, connectional, and functional diversity of cells. A wide variety of studies have shown that certain genes are expressed only in specific cell-types. Analysis of cell-type-specific gene expression patterns can provide insights into the relationship between genes, connectivity, brain regions, and cell-types. However, automated methods for identifying cell-type-specific genes are lacking to date. Results Here, we describe a set of computational methods for identifying cell-type-specific genes in the mouse brain by automated image computing of in situ hybridization (ISH) expression patterns. We applied invariant image feature descriptors to capture local gene expression information from cellular-resolution ISH images. We then built image-level representations by applying vector quantization on the image descriptors. We employed regularized learning methods for classifying genes specifically expressed in different brain cell-types. These methods can also rank image features based on their discriminative power. We used a data set of 2,872 genes from the Allen Brain Atlas in the experiments. Results showed that our methods are predictive of cell-type-specificity of genes. Our classifiers achieved AUC values of approximately 87% when the enrichment level is set to 20. In addition, we showed that the highly-ranked image features captured the relationship between cell-types. Conclusions Overall, our results showed that automated image computing methods could potentially be used to identify cell-type-specific genes in the mouse brain. PMID:24947138

2014-01-01

194

Assortative mixing in functional brain networks during epileptic seizures  

NASA Astrophysics Data System (ADS)

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

Bialonski, Stephan; Lehnertz, Klaus

2013-09-01

195

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

196

Space shuttle configuration accounting functional design specification  

NASA Technical Reports Server (NTRS)

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

1974-01-01

197

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

PubMed Central

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

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

2013-01-01

198

Functionally Enigmatic Genes: A Case Study of the Brain Ignorome  

PubMed Central

What proportion of genes with intense and selective expression in specific tissues, cells, or systems are still almost completely uncharacterized with respect to biological function? In what ways do these functionally enigmatic genes differ from well-studied genes? To address these two questions, we devised a computational approach that defines so-called ignoromes. As proof of principle, we extracted and analyzed a large subset of genes with intense and selective expression in brain. We find that publications associated with this set are highly skewed—the top 5% of genes absorb 70% of the relevant literature. In contrast, approximately 20% of genes have essentially no neuroscience literature. Analysis of the ignorome over the past decade demonstrates that it is stubbornly persistent, and the rapid expansion of the neuroscience literature has not had the expected effect on numbers of these genes. Surprisingly, ignorome genes do not differ from well-studied genes in terms of connectivity in coexpression networks. Nor do they differ with respect to numbers of orthologs, paralogs, or protein domains. The major distinguishing characteristic between these sets of genes is date of discovery, early discovery being associated with greater research momentum—a genomic bandwagon effect. Finally we ask to what extent massive genomic, imaging, and phenotype data sets can be used to provide high-throughput functional annotation for an entire ignorome. In a majority of cases we have been able to extract and add significant information for these neglected genes. In several cases—ELMOD1, TMEM88B, and DZANK1—we have exploited sequence polymorphisms, large phenome data sets, and reverse genetic methods to evaluate the function of ignorome genes. PMID:24523945

Pandey, Ashutosh K.; Lu, Lu; Wang, Xusheng; Homayouni, Ramin; Williams, Robert W.

2014-01-01

199

DNA microarray analysis of functionally discrete human brain regions reveals divergent transcriptional profiles  

PubMed Central

Transcriptional profiles within discrete human brain regions are likely to reflect structural and functional specialization. Using DNA microarray technology, this study investigates differences in transcriptional profiles of highly divergent brain regions (the cerebellar cortex and the cerebral cortex) as well as differences between two closely related brain structures (the anterior cingulate cortex and the dorsolateral prefrontal cortex). Replication of this study across three independent laboratories, to address false-positive and false-negative results using microarray technology, is also discussed. We find greater than a thousand transcripts to be differentially expressed between cerebellum and cerebral cortex and very few transcripts to be differentially expressed between the two neocortical regions. We further characterized transcripts that were found to be specifically expressed within brain regions being compared and found that ontological classes representing signal transduction machinery, neurogenesis, synaptic transmission, and transcription factors were most highly represented. PMID:14572446

Evans, S.J.; Choudary, P.V.; Vawter, M.P.; Li, J.; Meador-Woodruff, J.H.; Lopez, J.F.; Burke, S.M.; Thompson, R.C.; Myers, R.M.; Jones, E.G.; Bunney, W.E.; Watson, S.J.; Akil, H.

2010-01-01

200

Hierarchical Organization Unveiled by Functional Connectivity in Complex Brain Networks  

NASA Astrophysics Data System (ADS)

How do diverse dynamical patterns arise from the topology of complex networks? We study synchronization dynamics in the cortical brain network of the cat, which displays a hierarchically clustered organization, by modeling each node (cortical area) with a subnetwork of interacting excitable neurons. We find that in the biologically plausible regime the dynamics exhibits a hierarchical modular organization, in particular, revealing functional clusters coinciding with the anatomical communities at different scales. Our results provide insights into the relationship between network topology and functional organization of complex brain networks.

Zhou, Changsong; Zemanová, Lucia; Zamora, Gorka; Hilgetag, Claus C.; Kurths, Jürgen

2006-12-01

201

Material-specific difficulties in episodic memory tasks in mild traumatic brain injury.  

PubMed

The study examines acute, material-specific secondary memory performance in 26 patients with mild traumatic brain injury (MTBI) and 26 healthy controls, matched on demographic variables and indexes of crystallized intelligence. Neuropsychological tests were used to evaluate primary and secondary memory, executive functions, and verbal fluency. Participants were also tested on episodic memory tasks involving words, pseudowords, pictures of common objects, and abstract kaleidoscopic images. Patients showed reduced performance on episodic memory measures, and on tasks associated with visuospatial processing and executive function (Trail Making Test part B, semantic fluency). Significant differences between groups were also noted for correct rejections and response bias on the kaleidoscope task. MTBI patients' reduced performance on memory tasks for complex, abstract stimuli can be attributed to a dysfunction in the strategic component of memory process. PMID:20374085

Tsirka, Vassiliki; Simos, Panagiotis; Vakis, Antonios; Vourkas, Michael; Arzoglou, Vasileios; Syrmos, Nikolaos; Stavropoulos, Stavros; Micheloyannis, Sifis

2010-03-01

202

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

203

Hyperbaric oxygen therapy improves cognitive functioning after brain injury  

PubMed Central

Hyperbaric oxygen therapy has been widely applied and recognized in the treatment of brain injury; however, the correlation between the protective effect of hyperbaric oxygen therapy and changes of metabolites in the brain remains unclear. To investigate the effect and potential mechanism of hyperbaric oxygen therapy on cognitive functioning in rats, we established traumatic brain injury models using Feeney's free falling method. We treated rat models with hyperbaric oxygen therapy at 0.2 MPa for 60 minutes per day. The Morris water maze test for spatial navigation showed that the average escape latency was significantly prolonged and cognitive function decreased in rats with brain injury. After treatment with hyperbaric oxygen therapy for 1 and 2 weeks, the rats’ spatial learning and memory abilities were improved. Hydrogen proton magnetic resonance spectroscopy analysis showed that the N-acetylaspartate/creatine ratio in the hippocampal CA3 region was significantly increased at 1 week, and the N-acetylaspartate/choline ratio was significantly increased at 2 weeks after hyperbaric oxygen therapy. Nissl staining and immunohistochemical staining showed that the number of nerve cells and Nissl bodies in the hippocampal CA3 region was significantly increased, and glial fibrillary acidic protein positive cells were decreased after a 2-week hyperbaric oxygen therapy treatment. Our findings indicate that hyperbaric oxygen therapy significantly improves cognitive functioning in rats with traumatic brain injury, and the potential mechanism is mediated by metabolic changes and nerve cell restoration in the hippocampal CA3 region. PMID:25206655

Liu, Su; Shen, Guangyu; Deng, Shukun; Wang, Xiubin; Wu, Qinfeng; Guo, Aisong

2013-01-01

204

Structure, Expression, and Functional Analysis of a Na^+Dependent Glutamate\\/Aspartate Transporter from Rat Brain  

Microsoft Academic Search

Transport systems specific for L-glutamate and L-aspartate play an important role in the termination of neurotransmitter signals at excitatory synapses. We describe here the structure and function of a 66-kDa glycoprotein that was purified from rat brain and identified as an L-glutamate\\/L-aspartate transporter (GLAST). A GLAST-specific cDNA clone was isolated from a rat brain cDNA library. The cDNA insert encodes

Thorsten Storck; Stefan Schulte; Kay Hofmann; Wilhelm Stoffel

1992-01-01

205

Toward discovery science of human brain function  

E-print Network

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

Gabrieli, Susan

206

Evaluation of traumatic brain injury: brain potentials in diagnosis, function, and prognosis.  

PubMed

The focus of this review is an analysis of the use of event-related brain potential (ERP) abnormalities as indices of functional pathophysiology in survivors of traumatic brain injury (TBI). TBI may be the most prevalent but least understood neurological disorder in both civilian and military populations. In the military, thousands of new brain injuries occur yearly; this lends considerable urgency to the use of highly sensitive ERP tools to illuminate brain changes and to address remediation issues. We review the processes thought to be indexed by the cognitive components of the ERP and outline the rationale for applying ERPs to evaluate deficits after TBI. Studies in which ERPs were used to clarify the nature of cognitive complaints of TBI survivors are reviewed, emphasizing impairment in attention, information processing, and cognitive control. Also highlighted is research on the application of ERPs to predict emergence from coma and eventual outcome. We describe primary blast injury, the leading cause of TBI for active duty military personnel in present day warfare. The review concludes with a description of an ongoing investigation of mild TBI, aimed at using indices of brain structure and function to predict the course of posttraumatic stress disorder. An additional goal of this ongoing investigation is to characterize the structural and functional sequelae of blast injury. PMID:21356253

Duncan, Connie C; Summers, Angela C; Perla, Elizabeth J; Coburn, Kerry L; Mirsky, Allan F

2011-10-01

207

Psychotropic medication, psychiatric disorders, and higher brain functions  

PubMed Central

Conventional psychiatric diagnosis is founded on symptom description; this then governs the choice of psychotropic medication. This purely descriptive approach resembles a description of diphtheria from the premicrobiology era. Based on current advances in basic and clinical neuroscience, we propose inserting an intermediate level of analysis between psychiatric symptoms and pharmacologic modes of action. Paradigm 1 is to analyze psychiatric symptoms in terms of which higher brain function(s) is (are) abnormal, ie, symptoms should be analyzed as higher brain dysfunction: a case study in obsessive-compulsive disorder reveals pointers in four common symptoms to the higher functions of working memory, emotional overlay, absence of voluntary control, and the ability to evaluate personal mental phenomena. Paradigm 2 is to view psychotropic drugs as modifying normal higher brain functions, rather than merely treating symptoms, which they do only secondarily: thus depression may respond to agents that act on related aspects of mental life derived from higher brain functions, eg, the ability to enhance bonding. We advocate a strategy in which psychiatric illness is progressively reclassified through knowledge in clinical neuroscience and treatment targets are revised accordingly. PMID:22034249

Schulz, Pierre; Steimer, Thierry

2000-01-01

208

In search of biomarkers in psychiatry: EEG-based measures of brain function.  

PubMed

Current clinical parameters used for diagnosis and phenotypic definitions of psychopathology are both highly variable and subjective. Intensive research efforts for specific and sensitive biological markers, or biomarkers, for psychopathology as objective alternatives to the current paradigm are ongoing. While biomarker research in psychiatry has focused largely on functional neuroimaging methods for identifying the neural functions that associate with psychopathology, scalp electroencephalography (EEG) has been viewed, historically, as offering little specific brain source information, as scalp appearance is only loosely correlated to its brain source dynamics. However, ongoing advances in signal processing of EEG data can now deliver functional EEG brain-imaging with distinctly improved spatial, as well as fine temporal, resolution. One computational approach proving particularly useful for EEG cortical brain imaging is independent component analysis (ICA). ICA decomposition can be used to identify distinct cortical source activities that are sensitive and specific to the pathophysiology of psychiatric disorders. Given its practical research advantages, relatively low cost, and ease of use, EEG-imaging is now both feasible and attractive, in particular for studies involving the large samples required by genetically informative designs to characterize causal pathways to psychopathology. The completely non-invasive nature of EEG data acquisition, coupled with ongoing advances in dry, wireless, and wearable EEG technology, makes EEG-imaging increasingly attractive and appropriate for psychiatric research, including the study of developmentally young samples. Applied to large genetically and developmentally informative samples, EEG imaging can advance the search for robust diagnostic biomarkers and phenotypes in psychiatry. PMID:24273134

McLoughlin, Gráinne; Makeig, Scott; Tsuang, Ming T

2014-03-01

209

Structural and functional clusters of complex brain networks  

NASA Astrophysics Data System (ADS)

Recent research using the complex network approach has revealed a rich and complicated network topology in the cortical connectivity of mammalian brains. It is of importance to understand the implications of such complex network structures in the functional organization of the brain activities. Here we study this problem from the viewpoint of dynamical complex networks. We investigate synchronization dynamics on the corticocortical network of the cat by modeling each node (cortical area) of the network with a sub-network of interacting excitable neurons. We find that the network displays clustered synchronization behavior, and the dynamical clusters coincide with the topological community structures observed in the anatomical network. Our results provide insights into the relationship between the global organization and the functional specialization of the brain cortex.

Zemanová, Lucia; Zhou, Changsong; Kurths, Jürgen

2006-12-01

210

Specific Ways Brain SPECT Imaging Enhances Clinical Psychiatric Practice  

Microsoft Academic Search

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

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

2012-01-01

211

Functional characterization of transmembrane adenylyl cyclases from the honeybee brain.  

PubMed

The second messenger cAMP has a pivotal role in animals' physiology and behavior. Intracellular concentrations of cAMP are balanced by cAMP-synthesizing adenylyl cyclases (ACs) and cAMP-cleaving phosphodiesterases. Knowledge about ACs in the honeybee (Apis mellifera) is rather limited and only an ortholog of the vertebrate AC3 isoform has been functionally characterized, so far. Employing bioinformatics and functional expression we characterized two additional honeybee genes encoding membrane-bound (tm)ACs. The proteins were designated AmAC2t and AmAC8. Unlike the common structure of tmACs, AmAC2t lacks the first transmembrane domain. Despite this unusual topography, AmAC2t-activity could be stimulated by norepinephrine and NKH477 with EC(50s) of 0.07 ?M and 3 ?M. Both ligands stimulated AmAC8 with EC(50s) of 0.24 ?M and 3.1 ?M. In brain cryosections, intensive staining of mushroom bodies was observed with specific antibodies against AmAC8, an expression pattern highly reminiscent of the Drosophila rutabaga AC. In a current release of the honeybee genome database we identified three additional tmAC- and one soluble AC-encoding gene. These results suggest that (1) the AC-gene family in honeybees is comparably large as in other species, and (2) based on the restricted expression of AmAC8 in mushroom bodies, this enzyme might serve important functions in honeybee behavior. PMID:22426196

Balfanz, Sabine; Ehling, Petra; Wachten, Sebastian; Jordan, Nadine; Erber, Joachim; Mujagic, Samir; Baumann, Arnd

2012-06-01

212

Sustained deep-tissue pain alters functional brain connectivity  

PubMed Central

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

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

2013-01-01

213

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

Microsoft Academic Search

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

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

1992-01-01

214

Specific role of polysorbate 80 coating on the targeting of nanoparticles to the brain  

Microsoft Academic Search

It was reported that nanoparticles with polysorbate 80 (Tween 80, T-80) coating represented tools used for delivering drugs to brain. Nevertheless, disputations were once aroused for some complications. Aimed to have a better understanding of the specific role of T-80 coating on nanoparticles and simplify the problem, the direct observation of brain targeting combined with in vivo experiments was carried

Wangqiang Sun; Changsheng Xie; Huafang Wang; Yu Hu

2004-01-01

215

Mental Imagery of Faces and Places Activates Corresponding Stimulus-Specific Brain  

E-print Network

Mental Imagery of Faces and Places Activates Corresponding Stimulus-Specific Brain Regions K. M. O happens in the brain when you conjure up a mental image in your mind's eye? We tested whether the particular regions of extrastriate cortex activated during mental imagery depend on the content of the image

Kanwisher, Nancy

216

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

E-print Network

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

217

USEFULLNESS OF FUNCTIONAL MRI ASSOCIATED WITH PET SCAN AND EVOKED POTENTIALS IN THE EVALUATION OF BRAIN FUNCTIONS AFTER  

E-print Network

USEFULLNESS OF FUNCTIONAL MRI ASSOCIATED WITH PET SCAN AND EVOKED POTENTIALS IN THE EVALUATION CEREBRALES GRAVES : résultats préliminaires. Key Words : brain injury, coma, MRI, functional imaging usefulness of functional MRI (fMRI) for the evaluation of brain functions after severe brain injury, when

Paris-Sud XI, Université de

218

Brain-specific noncoding RNAs are likely to originate in repeats and may play a role in up-regulating genes in cis.  

PubMed

The mouse and human brain express a large number of noncoding RNAs (ncRNAs). Some of these are known to participate in neural progenitor cell fate determination, cell differentiation, neuronal and synaptic plasticity and transposable elements derived ncRNAs contribute to somatic variation. Dysregulation of specific long ncRNAs (lncRNAs) has been shown in neuro-developmental and neuro-degenerative diseases thus highlighting the importance of lncRNAs in brain function. Even though it is known that lncRNAs are expressed in cells at low levels in a tissue-specific manner, bioinformatics analyses of brain-specific ncRNAs has not been performed. We analyzed previously published custom microarray ncRNA expression data generated from twelve human tissues to identify tissue-specific ncRNAs. We find that among the 12 tissues studied, brain has the largest number of ncRNAs. Our analyses show that genes in the vicinity of brain-specific ncRNAs are significantly up regulated in the brain. Investigations of repeat representation show that brain-specific ncRNAs are significantly more likely to originate in repeat regions especially DNA/TcMar-Tigger compared with non-tissue-specific ncRNAs. We find SINE/Alus depleted from brain-specific dataset when compared with non-tissue-specific ncRNAs. Our data provide a bioinformatics comparison between brain-specific and non tissue-specific ncRNAs. This article is part of a Directed Issue entitled: The Non-coding RNA Revolution. PMID:24993078

Francescatto, Margherita; Vitezic, Morana; Heutink, Peter; Saxena, Alka

2014-09-01

219

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

SciTech Connect

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

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

2008-12-01

220

Preoperative functional MRI localization of language areas in Chinese patients with brain tumors  

PubMed Central

Ten Chinese patients with brain tumors involving language regions were selected. Preoperative functional MRI was performed to locate Broca's or Wernicke's area, and the cortex that was essential for language function was determined by electrocortical mapping. A site-by-site comparison between functional MRI and electrocortical mapping was performed with the aid of a neuronavigation device. Results showed that the sensitivity and specificity of preoperative functional MRI were 80.0% and 85.0% in Broca's area and 66.6% and 85.2% in Wernicke's area, respectively. These experimental findings indicate that functional MRI is an accurate, reliable technique with which to identify the location of Wernicke's area or Broca's area in patients with brain tumors.

Xia, Hechun; Huang, Wei; Wu, Liang; Ma, Hui; Wang, Xiaodong; Chen, Xuexin; Sun, Shengyu; Jia, Xiaoxiong

2012-01-01

221

Neuroinflammation and Brain Functional Disconnection in Alzheimer’s Disease  

PubMed Central

Neuroinflammation and brain functional disconnection result from ?-amyloid (A?) accumulation and play fundamental roles in the pathogenesis of Alzheimer’s disease (AD). We investigated possible correlations between these two AD-associated phenomena using DTI-based tractography and immunologic analyses in people with amnestic mild cognitive impairment (aMCI) and AD. DTI-Analyses focused on corpus callosum (CC). We found that frontal CC regions were preserved with respect to the posterior ones in aMCI; in these individuals significant correlations were seen between DTI-derived metrics in frontal-parietal CC areas and A?42-stimulated BDNF-producing CD4+ T lymphocytes and PDL-1-expressing CD14+ cells. These associations were lost in AD where DTI data involving the same CC areas correlated instead with A?42-stimulated interleukin (IL)-21 producing CD4+ T lymphocytes. Higher susceptibility to PDL-1-mediated apoptosis of A?42-specific lymphocytes and BDNF-associated survival of existing neurons could contribute to the relative CC structure preservation seen in aMCI. These potentially protective mechanisms are lost in frank AD, when severe alterations in the CC are mirrored in peripheral blood by proinflammatory cytokines-producing T cells. Monitoring of immune cells in peripheral blood could have a prognostic value in AD. PMID:24324435

Baglio, Francesca; Saresella, Marina; Preti, Maria Giulia; Cabinio, Monia; Griffanti, Ludovica; Marventano, Ivana; Piancone, Federica; Calabrese, Elena; Nemni, Raffaello; Clerici, Mario

2013-01-01

222

Nutrition, brain function and cognitive performance  

Microsoft Academic Search

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

Harris R Lieberman

2003-01-01

223

Predictors of physical functioning in postoperative brain tumor patients.  

PubMed

A cross-sectional predictive design was used to study the relationships among recovery symptoms, mood state, and physical functioning and to identify predictors of physical functioning in patients who underwent surgery for brain tumor at the first follow-up visit (2 weeks) after hospital discharge. The sample included 88 patients who were 18 years or older, had full level of consciousness, and underwent first-time surgery for brain tumor without other adjuvant treatments from a tertiary hospital in Bangkok, Thailand. Descriptive statistics, Pearson product-moment correlation coefficient, and multiple regression were used for data analysis. The results revealed that most participants were women (75%) with an average age of 45.18 ± 11.49 years, having benign brain tumors (91%) and pathological results as meningioma (48.9%). The most common recovery symptoms were pain (mean = 3.2, SD = 2.6) and sleep disturbance (mean = 3.1, SD = 3.0). As for mood state, the problem of confusion was found the most (mean = 4.6, SD = 2.7). The physical functioning problem found the most was work aspect (mean = 66.3, SD = 13.3). Recovery symptoms had positive relationships with physical functioning and mood state (r = .406, .716; p < .01), respectively. At the same time, mood state had positive relationships with physical functioning (r = .288, p < .01). Recovery symptoms, total mood disturbance, fatigue, and vigor were statistically significant predictors of physical functioning and could explain variance of postoperative physical functioning in these patients at 2 weeks after discharge by 35%. Total mood disturbance was the strongest predictor of physical functioning followed by vigor, fatigue, and recovery symptom, respectively. Interventions to improve physical functioning in postoperative brain tumor patients during home recovery should account for not only recovery symptom management but also mood state. PMID:25565598

Tankumpuan, Thitipong; Utriyaprasit, Ketsarin; Chayaput, Prangtip; Itthimathin, Parunut

2015-02-01

224

Predicting premorbid neuropsychological functioning following pediatric traumatic brain injury  

Microsoft Academic Search

This study examined the prediction of premorbid neuropsychological functioning using data from an ongoing prospective study of traumatic brain injuries (TBI) in children ages 6 to 12 years. Prediction equations were derived based on 80 children with orthopedic injuries (OI), who served as a comparison group for the children with TBI. Collectively, parent ratings of premorbid school performance, maternal ethnicity,

Keith Owen Yeates; H. Gerry Taylor

1997-01-01

225

Automated Talairach Atlas Labels For Functional Brain Mapping  

E-print Network

Automated Talairach Atlas Labels For Functional Brain Mapping Jack L. Lancaster,* Marty G. Woldorff, Lawrence M. Parsons, Mario Liotti, Catarina S. Freitas, Lacy Rainey, Peter V. Kochunov, Dan Nickerson Talairach Atlas, called the Talairach Daemon (TD), was previously introduced [Lancaster et al., 1997

226

Fractal analysis of resting state functional connectivity of the brain  

E-print Network

Fractal analysis of resting state functional connectivity of the brain Wonsang You1 , Sophie Achard, Germany 2 GIPSA-lab, CNRS, UMR 5216, Grenoble, France 3 Biosystems Engineering, Fraunhofer neuroimaging data tend to exhibit fractal behavior where their power spectrums follow power-law scaling

227

Functional Improvement Between Brain Death Declaration and Organ Harvesting  

Microsoft Academic Search

IntroductionThe quality of harvested organs is crucial for graft survival and for posttransplant evolution. This study sought to investigate the evolution of the functional status of brain death (BD) patients during the period between declaration and organ harvesting (BD duration).

I. Grigoras; M. Blaj; O. Chelarescu; C. Craus; G. Florin

2010-01-01

228

SYNAPSES IN NORMAL AND DISEASED BRAIN FUNCTION Roberto Malinow  

E-print Network

in normal and abnormal brain function. To achieve this end we combine electrophysiolgical, imaging plasticity. Another series of studies is examining the effects of beta amyloid, a peptide thought to play have found that neural activity enhances beta amyloid formation; in turn beta amyloid taps into normal

Gruen, Sonja

229

Functional brain mapping of the relaxation response and meditation  

Microsoft Academic Search

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

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

2000-01-01

230

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

231

Modulatory Interactions of Resting-State Brain Functional Connectivity  

PubMed Central

The functional brain connectivity studies are generally based on the synchronization of the resting-state functional magnetic resonance imaging (fMRI) signals. Functional connectivity measures usually assume a stable relationship over time; however, accumulating studies have reported time-varying properties of strength and spatial distribution of functional connectivity. The present study explored the modulation of functional connectivity between two regions by a third region using the physiophysiological interaction (PPI) technique. We first identified eight brain networks and two regions of interest (ROIs) representing each of the networks using a spatial independent component analysis. A voxel-wise analysis was conducted to identify regions that showed modulatory interactions (PPI) with the two ROIs of each network. Mostly, positive modulatory interactions were observed within regions involved in the same system. For example, the two regions of the dorsal attention network revealed modulatory interactions with the regions related to attention, while the two regions of the extrastriate network revealed modulatory interactions with the regions in the visual cortex. In contrast, the two regions of the default mode network (DMN) revealed negative modulatory interactions with the regions in the executive network, and vice versa, suggesting that the activities of one network may be associated with smaller within network connectivity of the competing network. These results validate the use of PPI analysis to study modulation of resting-state functional connectivity by a third region. The modulatory effects may provide a better understanding of complex brain functions. PMID:24023609

Di, Xin; Biswal, Bharat B.

2013-01-01

232

Internship MASTER 2012 Joint estimation of primary brain functional territories from BOLD functional  

E-print Network

. Requirements: Matlab, C/C++, good knowledge in statistics. Prior experience with medical imaging data replication to functional ASL. The internship work will be dedicated to adapt different image processing, Brain perfusion, Image processing, Statistical detection, Brain imaging , Cerveau, IRM, Traitements d'images

Dobigeon, Nicolas

233

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. PMID:24765064

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

2014-01-01

234

Monoamines tissue content analysis reveals restricted and site-specific correlations in brain regions involved in cognition.  

PubMed

The dopamine (DA), noradrenalin (NA) and serotonin (5-HT) monoaminergic systems are deeply involved in cognitive processes via their influence on cortical and subcortical regions. The widespread distribution of these monoaminergic networks is one of the main difficulties in analyzing their functions and interactions. To address this complexity, we assessed whether inter-individual differences in monoamine tissue contents of various brain areas could provide information about their functional relationships. We used a sensitive biochemical approach to map endogenous monoamine tissue content in 20 rat brain areas involved in cognition, including 10 cortical areas and examined correlations within and between the monoaminergic systems. Whereas DA content and its respective metabolite largely varied across brain regions, the NA and 5-HT contents were relatively homogenous. As expected, the tissue content varied among individuals. Our analyses revealed a few specific relationships (10%) between the tissue content of each monoamine in paired brain regions and even between monoamines in paired brain regions. The tissue contents of NA, 5-HT and DA were inter-correlated with a high incidence when looking at a specific brain region. Most correlations found between cortical areas were positive while some cortico-subcortical relationships regarding the DA, NA and 5-HT tissue contents were negative, in particular for DA content. In conclusion, this work provides a useful database of the monoamine tissue content in numerous brain regions. It suggests that the regulation of these neuromodulatory systems is achieved mainly at the terminals, and that each of these systems contributes to the regulation of the other two. PMID:24120557

Fitoussi, A; Dellu-Hagedorn, F; De Deurwaerdère, P

2013-01-01

235

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

236

The Functional Connectivity Landscape of the Human Brain  

PubMed Central

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

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

2014-01-01

237

Identification of brain-specific angiogenesis inhibitor 2 as an interaction partner of glutaminase interacting protein  

SciTech Connect

Highlights: {yields} Brain-specific angiogenesis inhibitor 2 (BAI2) is a new partner protein for GIP. {yields} BAI2 interaction with GIP was revealed by yeast two-hybrid assay. {yields} Binding of BAI2 to GIP was characterized by NMR, CD and fluorescence. {yields} BAI2 and GIP binding was mediated through the C-terminus of BAI2. -- Abstract: The vast majority of physiological processes in living cells are mediated by protein-protein interactions often specified by particular protein sequence motifs. PDZ domains, composed of 80-100 amino acid residues, are an important class of interaction motif. Among the PDZ-containing proteins, glutaminase interacting protein (GIP), also known as Tax Interacting Protein TIP-1, is unique in being composed almost exclusively of a single PDZ domain. GIP has important roles in cellular signaling, protein scaffolding and modulation of tumor growth and interacts with a number of physiological partner proteins, including Glutaminase L, {beta}-Catenin, FAS, HTLV-1 Tax, HPV16 E6, Rhotekin and Kir 2.3. To identify the network of proteins that interact with GIP, a human fetal brain cDNA library was screened using a yeast two-hybrid assay with GIP as bait. We identified brain-specific angiogenesis inhibitor 2 (BAI2), a member of the adhesion-G protein-coupled receptors (GPCRs), as a new partner of GIP. BAI2 is expressed primarily in neurons, further expanding GIP cellular functions. The interaction between GIP and the carboxy-terminus of BAI2 was characterized using fluorescence, circular dichroism (CD) and nuclear magnetic resonance (NMR) spectroscopy assays. These biophysical analyses support the interaction identified in the yeast two-hybrid assay. This is the first study reporting BAI2 as an interaction partner of GIP.

Zencir, Sevil [Department of Biochemistry, Faculty of Science, Ege University, Izmir 35100 (Turkey)] [Department of Biochemistry, Faculty of Science, Ege University, Izmir 35100 (Turkey); Ovee, Mohiuddin [Department of Chemistry and Biochemistry, Auburn University, Auburn, AL 36849 (United States)] [Department of Chemistry and Biochemistry, Auburn University, Auburn, AL 36849 (United States); Dobson, Melanie J. [Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, NS, Canada B3H 4R2 (Canada)] [Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, NS, Canada B3H 4R2 (Canada); Banerjee, Monimoy [Department of Chemistry and Biochemistry, Auburn University, Auburn, AL 36849 (United States)] [Department of Chemistry and Biochemistry, Auburn University, Auburn, AL 36849 (United States); Topcu, Zeki, E-mail: zeki.topcu@ege.edu.tr [Department of Pharmaceutical Biotechnology, Faculty of Pharmacy, Ege University, Izmir 35100 (Turkey)] [Department of Pharmaceutical Biotechnology, Faculty of Pharmacy, Ege University, Izmir 35100 (Turkey); Mohanty, Smita, E-mail: mohansm@auburn.edu [Department of Chemistry and Biochemistry, Auburn University, Auburn, AL 36849 (United States)] [Department of Chemistry and Biochemistry, Auburn University, Auburn, AL 36849 (United States)

2011-08-12

238

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

239

Functional MRI and intraoperative brain mapping to evaluate brain plasticity in patients with brain tumours and hemiparesis  

PubMed Central

OBJECTIVE—To support the hypothesis about the potential compensatory role of ipsilateral corticofugal pathways when the contralateral pathways are impaired by brain tumours.?METHODS—Retrospective analysis was carried out on the results of functional MRI (fMRI) of a selected group of five paretic patients with Rolandic brain tumours who exhibited an abnormally high ipsilateral/contralateral ratio of activation—that is, movements of the paretic hand activated predominately the ipsilateral cortex. Brain activation was achieved with a flexion extension of the fingers. Statistical parametric activation was obtained using a t test and a threshold of p<0.001. These patients, candidates for tumour resection, also underwent cortical intraoperative stimulation that was correlated to the fMRI spatial data using three dimensional reconstructions of the brain. Three patients also had postoperative control fMRI.?RESULTS—The absence of fMRI activation of the primary sensorimotor cortex normally innervating the paretic hand for the threshold chosen, was correlated with completely negative cortical responses of the cortical hand area during the operation. The preoperative fMRI activation of these patients predominantly found in the ipsilateral frontal and primary sensorimotor cortices could be related to the residual ipsilateral hand function. Postoperatively, the fMRI activation returned to more classic patterns of activation, reflecting the consequences of therapy.?CONCLUSION—In paretic patients with brain tumours, ipsilateral control could be implicated in the residual hand function, when the normal primary pathways are impaired. The possibility that functional tissue still remains in the peritumorous sensorimotor cortex even when the preoperative fMRI and the cortical intraoperative stimulations are negative, should be taken into account when planning the tumour resection and during the operation.?? PMID:10990503

Roux, F; Boulanouar, K; Ibarrola, D; Tremoulet, M; Chollet, F; Berry, I

2000-01-01

240

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

Microsoft Academic Search

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

Hu Yang

2010-01-01

241

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

PubMed Central

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

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

2014-01-01

242

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. PMID:23986665

Edelman, Gerald M.; Gally, Joseph A.

2013-01-01

243

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

PubMed Central

SUMMARY Parkinson’s disease (PD) is characterized by dopaminergic neurodegeneration in the nigrostriatal region of the brain; however, the neurodegeneration extends well beyond dopaminergic neurons. To gain a better understanding of the molecular changes relevant to PD, we applied two-dimensional LC-MS/MS to comparatively analyze the proteome changes in four brain regions (striatum, cerebellum, cortex, and the rest of brain) using a MPTP-induced PD mouse model with the objective to identify nigrostriatal-specific and other region-specific protein abundance changes. The combined analyses resulted in the identification of 4,895 non-redundant proteins with at least two unique peptides per protein. The relative abundance changes in each analyzed brain region were estimated based on the spectral count information. A total of 518 proteins were observed with significant MPTP-induced changes across different brain regions. 270 of these proteins were observed with specific changes occurring either only in the striatum and/or in the rest of the brain region that contains substantia nigra, suggesting that these proteins are associated with the underlying nigrostriatal pathways. Many of the proteins that exhibit significant abundance changes were associated with dopamine signaling, mitochondrial dysfunction, the ubiquitin system, calcium signaling, the oxidative stress response, and apoptosis. A set of proteins with either consistent change across all brain regions or with changes specific to the cortex and cerebellum regions were also detected. One of the interesting proteins is ubiquitin specific protease (USP9X), a deubiquination enzyme involved in the protection of proteins from degradation and promotion of the TGF-? pathway, which exhibited altered abundances in all brain regions. Western blot validation showed similar spatial changes, suggesting that USP9X is potentially associated with neurodegeneration. Together, this study for the first time presents an overall picture of proteome changes underlying both nigrostriatal pathways and other brain regions potentially involved in MPTP-induced neurodegeneration. The observed molecular changes provide a valuable reference resource for future hypothesis-driven functional studies of PD. PMID:20155936

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

2010-01-01

244

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

SciTech Connect

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

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

2010-02-15

245

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

E-print Network

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

Lowery, Laura Anne

246

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

E-print Network

-infrared light can pass easily through structures such as the skull, penetrating the brain and allowing GmbH & Co. KG Berlin · New York Adult human brain functional imaging studies have previously been

247

Cross-hemispheric functional connectivity in the human fetal brain  

PubMed Central

Compelling evidence indicates that psychiatric and developmental disorders are generally caused by disruptions in the functional connectivity (FC) of brain networks. Events occurring during development, and in particular during fetal life, have been implicated in the genesis of such disorders. However, the developmental timetable for the emergence of neural FC during human fetal life is unknown. We present the results of resting-state functional magnetic resonance imaging performed in 25 healthy human fetuses in the second and third trimesters of pregnancy (24 to 38 weeks of gestation). We report the presence of bilateral fetal brain FC and regional and age-related variation in FC. Significant bilateral connectivity was evident in half of the 42 areas tested, and the strength of FC between homologous cortical brain regions increased with advancing gestational age. We also observed medial to lateral gradients in fetal functional brain connectivity. These findings improve understanding of human fetal central nervous system development and provide a basis for examining the role of insults during fetal life in the subsequent development of disorders in neural FC. PMID:23427244

Thomason, ME; Dassanayake, MT; Shen, S; Katkuri, Y; Alexis, M; Anderson, AL; Yeo, L; Mody, S; Hernandez-Andrade, E; Hassan, SS; Studholme, C; Jeong, JW; Romero, R

2013-01-01

248

Functional brain imaging of tobacco use and dependence  

PubMed Central

While most cigarette smokers endorse a desire to quit smoking, only about 14% to 49% will achieve abstinence after 6 months or more of treatment. A greater understanding of the effects of smoking on brain function may (in conjunction with other lines of research) result in improved pharmacological (and behavioral) interventions. Many research groups have examined the effects of acute and chronic nicotine/cigarette exposure on brain activity using functional imaging; the purpose of this paper is to synthesize findings from such studies and present a coherent model of brain function in smokers. Responses to acute administration of nicotine/smoking include: a reduction in global brain activity; activation of the prefrontal cortex, thalamus, and visual system; activation of the thalamus and visual cortex during visual cognitive tasks; and increased dopamine (DA) concentration in the ventral striatum/nucleus accumbens. Responses to chronic nicotine/cigarette exposure include decreased monoamine oxidase (MAO) A and B activity in the basal ganglia and a reduction in ?4?2 nicotinic acetylcholine receptor (nAChR) availability in the thalamus and putamen. Taken together, these findings indicate that smoking enhances neurotransmission through cortico-basal ganglia-thalamic circuits either by direct stimulation of nAChRs, indirect stimulation via DA release or MAO inhibition, or a combination of these factors. Activation of this circuitry may be responsible for the effects of smoking seen in tobacco dependent subjects, such as improvements in attentional performance, mood, anxiety, and irritability. PMID:15979645

Brody, Arthur L.

2010-01-01

249

Memory and the developing brain: short-term and long-term memory function and the heterogeneity of brain maturation.  

E-print Network

??In this thesis, the developmental brain structure and development of memory functions are investigated, both separately and conjointly. First, the different developmental trajectories of cortical… (more)

Østby, Ylva

2011-01-01

250

Functional MRI and the Study of Human Consciousness & Functional brain imaging offers new opportunities for the  

E-print Network

analysis of multiple experimental datasets. Here, four preprocessed datasets from the National fMRI Data functional brain imaging, offers new prospects for a science of consciousness. Most PET and fMRI research

Gordon, Geoffrey J.

251

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

PubMed Central

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

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

2014-01-01

252

Cross-Validation of Deformable Registration With Field Maps in Functional Magnetic Resonance Brain Imaging  

Microsoft Academic Search

The localization of brain functional activity with respect to brain anatomy requires registration between a functional image and a reference high-resolution anatomical image. The fast functional magnetic resonance brain images acquired via echo planar imaging (EPI) in functional magnetic resonance imaging (fMRI) suffer from local geometric distortions. After performing standard rigid or affine registration, local nonlinear distortions of up to

Ali Gholipour; Nasser Kehtarnavaz; Kaundinya Gopinath; Richard Briggs

2008-01-01

253

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

PubMed Central

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

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

2014-01-01

254

In Vivo Characterization of Traumatic Brain Injury Neuropathology with Structural and Functional Neuroimaging  

PubMed Central

Quantitative neuroimaging is increasingly used to study the effects of traumatic brain injury (TBI) on brain structure and function. This paper reviews quantitative structural and functional neuroimaging studies of patients with TBI, with an emphasis on the effects of diffuse axonal injury (DAI), the primary neuropathology in TBI. Quantitative structural neuroimaging has evolved from simple planometric measurements through targeted region-of-interest analyses to whole-brain analysis of quantified tissue compartments. Recent studies converge to indicate widespread volume loss of both gray and white matter in patients with moderate-to-severe TBI. These changes can be documented even when patients with focal lesions are excluded. Broadly speaking, performance on standard neuropsychological tests of speeded information processing are related to these changes, but demonstration of specific brain-behavior relationships requires more refined experimental behavioral measures. The functional consequences of these structural changes can be imaged with activation functional neuroimaging. Although this line of research is at an early stage, results indicate that TBI causes a more widely dispersed activation in frontal and posterior cortices. Further progress in analysis of the consequences of TBI on neural structure and function will require control of variability in neuropathology and behavior. PMID:17020478

LEVINE, BRIAN; FUJIWARA, ESTHER; O’CONNOR, CHARLENE; RICHARD, NADINE; KOVACEVIC, NATASA; MANDIC, MARINA; RESTAGNO, ADRIANA; EASDON, CRAIG; ROBERTSON, IAN H.; GRAHAM, SIMON J.; CHEUNG, GORDON; GAO, FUQIANG; SCHWARTZ, MICHAEL L.; BLACK, SANDRA E.

2007-01-01

255

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

PubMed

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

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

2014-01-01

256

Partial sleep in the context of augmentation of brain function  

PubMed Central

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

Pigarev, Ivan N.; Pigareva, Marina L.

2014-01-01

257

Patients with fibromyalgia display less functional connectivity in the brain’s pain inhibitory network  

PubMed Central

Background There is evidence for augmented processing of pain and impaired endogenous pain inhibition in Fibromyalgia syndrome (FM). In order to fully understand the mechanisms involved in FM pathology, there is a need for closer investigation of endogenous pain modulation. In the present study, we compared the functional connectivity of the descending pain inhibitory network in age-matched FM patients and healthy controls (HC). We performed functional magnetic resonance imaging (fMRI) in 42 subjects; 14 healthy and 28 age-matched FM patients (2 patients per HC), during randomly presented, subjectively calibrated pressure pain stimuli. A seed-based functional connectivity analysis of brain activity was performed. The seed coordinates were based on the findings from our previous study, comparing the fMRI signal during calibrated pressure pain in FM and HC: the rostral anterior cingulate cortex (rACC) and thalamus. Results FM patients required significantly less pressure (kPa) to reach calibrated pain at 50?mm on a 0–100 visual analogue scale (p?brain’s pain inhibitory network during calibrated pressure pain, compared to healthy controls. The present study provides brain-imaging evidence on how brain regions involved in homeostatic control of pain are less connected in FM patients. It is possible that the dysfunction of the descending pain modulatory network plays an important role in maintenance of FM pain and our results may translate into clinical implications by using the functional connectivity of the pain modulatory network as an objective measure of pain dysregulation. PMID:22537768

2012-01-01

258

2IW05 Software Specification Functionality Specification in Z  

E-print Network

Type: the largest set containing the elements of the set Benefits: 1 avoids paradoxical definitions of the set Benefits: 1 avoids paradoxical definitions: Russel = {x | x / x}, Russel Russel? 2 facilitates correct specification a : Apple; o : Orange; a = o; #12;Set vs. Type Type: the largest set containing

Mousavi, Mohammad

259

Neurocognitive function after radiotherapy for paediatric brain tumours.  

PubMed

The brain is highly vulnerable to neurotoxic agents during the prime learning period of a child's life. Paediatric patients with brain tumours who are treated with cranial radiation therapy (CRT) often go on to develop neurocognitive deficits, which are reflected in poor academic achievement and impaired memory, attention and processing speed. The extent of these delayed effects varies with radiation dose, brain volume irradiated, and age at treatment, and might also be influenced by genetic factors and individual susceptibility. CRT-induced impairment involves axonal damage and disruption of white matter growth, and can affect brain structures implicated in memory function and neurogenesis, such as the hippocampus. In this article, we review the underlying mechanisms and clinical consequences of CRT-induced neurocognitive damage in survivors of paediatric brain tumours. We discuss the recent application of neuroimaging technologies to identify white matter injury following CRT, and highlight new radiation techniques, pharmacological and neurological interventions, as well as rehabilitation programmes that have potential to minimize neurocognitive impairment following CRT. PMID:22964509

Padovani, Laetitia; André, Nicolas; Constine, Louis S; Muracciole, Xavier

2012-10-01

260

Specific benzodiazepine receptors in rat brain characterized by high-affinity (3H)diazepam binding.  

PubMed Central

[3H]Diazepam appears to bind specifically to a single, saturable, binding site located on rat brain membranes, with an affinity constant near 3 nM at pH 7.4. Specific binding constitutes more than 90% of total binding at 0 degrees and less than 10% of total binding at 37 degrees. Arrhenius plots suggest a sharp conformational change in the diazepam receptor near 18 degrees. Mitochondrial fractions from rat kidney, liver, and lung exhibit some [3H]diazepam binding that can be displaced by nonradioactive diazepam and several other benzodiazepines. However, Ro-4864, which is almost inactive in displacing [3H]diazepam from brain membranes, is extremely potent in displacing it from kidney mitochondria. Conversely, clonazepam, the most potent inhibitor of brain binding, is an extremely weak inhibitor of kidney binding. Furthermore, diazepam binding to kidney mitochondria has an affinity constantof 40 nM, about 15 times higher than that in brain. No specific diazepam binding was detected in intestine or skeletal muscle. Thus, specific [3H]diazepam binding to membranes appears to be restricted to brain, where it is unevenly distributed: the density of diazepam receptors is about five times higher in cortex (the highest density) than in pons-meddula (lowest density). Trypsin and chymotrypsin completely abolished specific [3H]diazepambinding in brain and kidney. Images PMID:20632

Braestrup, C; Squires, R F

1977-01-01

261

Totally Tubular: The Mystery behind Function and Origin of the Brain Ventricular System  

PubMed Central

Summary A unique feature of the vertebrate brain is the brain ventricular system, a series of connected cavities which are filled with cerebrospinal fluid (CSF) and surrounded by neuroepithelium. While CSF is critical for both adult brain function and embryonic brain development, neither development nor function of the brain ventricular system is fully understood. In this review, we discuss the mystery of why vertebrate brains have ventricles, and whence they originate. The brain ventricular system develops from the lumen of the neural tube, as the neuroepithelium undergoes morphogenesis. The molecular mechanisms underlying this ontogeny are described. We discuss possible functions of both adult and embryonic brain ventricles, as well as major brain defects that are associated with CSF and brain ventricular abnormalities. We conclude that vertebrates have taken advantage of their neural tube to form the essential brain ventricular system. PMID:19274662

Lowery, Laura Anne; Sive, Hazel

2010-01-01

262

Recruiting specialized macrophages across the borders to restore brain functions  

PubMed Central

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

Corraliza, Inés

2014-01-01

263

Transcranial brain stimulation to promote functional recovery after stroke  

PubMed Central

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

Raffin, Estelle; Siebner, Hartwig R.

2014-01-01

264

Executive Function Outcomes Following Traumatic Brain Injury in Young Children: A Five Year Follow-Up  

Microsoft Academic Search

Little is known about the long-term effects of traumatic brain injury (TBI) in very young children. This study used a prospective, cross-sectional design to investigate the impact of TBI on executive function (EF) outcomes in children who sustained a TBI before the age of seven. The study aimed to identify specific or global EF deficits five years post-TBI, and to

Caroline Nadebaum; Vicki Anderson; Cathy Catroppa

2007-01-01

265

FXYD7 is a brain-specific regulator of Na,K-ATPase ?1–? isozymes  

PubMed Central

Recently, corticosteroid hormone-induced factor (CHIF) and the ?-subunit, two members of the FXYD family of small proteins, have been identified as regulators of renal Na,K-ATPase. In this study, we have investigated the tissue distribution and the structural and functional properties of FXYD7, another family member which has not yet been characterized. Expressed exclusively in the brain, FXYD7 is a type I membrane protein bearing N-terminal, post-translationally added modifications on threonine residues, most probably O-glycosylations that are important for protein stabilization. Expressed in Xenopus oocytes, FXYD7 can interact with Na,K-ATPase ?1–?1, ?2–?1 and ?3–?1 but not with ?–?2 isozymes, whereas, in brain, it is only associated with ?1–? isozymes. FXYD7 decreases the apparent K+ affinity of ?1–?1 and ?2–?1, but not of ?3–?1 isozymes. These data suggest that FXYD7 is a novel, tissue- and isoform-specific Na,K-ATPase regulator which could play an important role in neuronal excitability. PMID:12093728

Béguin, Pascal; Crambert, Gilles; Monnet-Tschudi, Florianne; Uldry, Marc; Horisberger, Jean-Daniel; Garty, Haim; Geering, Käthi

2002-01-01

266

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

PubMed Central

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

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

2014-01-01

267

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

PubMed Central

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

Bock, Jörg; Riedel, Anett; Braun, Katharina

2012-01-01

268

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

PubMed Central

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

Heath, R G

1976-01-01

269

Brain-Specific Homeobox Factor as a Target Selector for Glucocorticoid Receptor in Energy Balance  

PubMed Central

The molecular basis underlying the physiologically well-defined orexigenic function of glucocorticoid (Gc) is unclear. Brain-specific homeobox factor (Bsx) is a positive regulator of the orexigenic neuropeptide, agouti-related peptide (AgRP), in AgRP neurons of the hypothalamic arcuate nucleus. Here, we show that in response to fasting-elevated Gc levels, Gc receptor (GR) and Bsx synergize to direct activation of AgRP transcription. This synergy is dictated by unique sequence features in a novel Gc response element in AgRP (AgRP-GRE). In contrast to AgRP-GRE, Bsx suppresses transactivation directed by many conventional GREs, functioning as a gene context-dependent modulator of GR actions or a target selector for GR. Consistent with this finding, AgRP-GRE drives fasting-dependent activation of a target gene specifically in GR+ Bsx+ AgRP neurons. These results define AgRP as a common orexigenic target gene of GR and Bsx and provide an opportunity to identify their additional common targets, facilitating our understanding of the molecular basis underlying the orexigenic activity of Gc and Bsx. PMID:23671185

Lee, Bora; Kim, Sun-Gyun; Kim, Juhee; Choi, Kwan Yong; Lee, Soo-Kyung

2013-01-01

270

Assessing blood-brain barrier function using in vitro assays.  

PubMed

The impermeability of the blood-brain barrier (BBB) is due to a number of properties including tight junctions on adjoining endothelial cells, absence of pinocytic vesicles, and expression of multidrug transporters. Although the permeability of many chemicals can be predicted by their polarity, or oil/water partition coefficient, many lipophilic chemicals are not permeable because of multidrug transporters at the luminal and abluminal membranes. In contrast, many nutrients, which are usually polar, cross the BBB more readily than predicted by their oil/water partition coefficients due to the expression of specific nutrient transporters. In vitro models are being developed because rodent models are of low input and relatively expensive. Isolated brain microvessels and cell culture models each offers certain advantages and disadvantages. Isolated brain microvessels are useful in measuring multidrug drug transporters and tight junction integrity, whereas cell culture models allow the investigator to measure directional transport and can be genetically manipulated. In this chapter, we describe how to isolate large batches of brain microvessels from freshly slaughtered cows. The different steps in the isolation procedure include density gradient centrifugations and filtering. Purity is determined microscopically and by marker enzymes. Permeability is assessed by measuring the uptake of fluorescein-labeled dextran in an assay that has been optimized to have a large dynamic range and low inter-day variability. We also describe how to evaluate transendothelial cell electrical resistance and paracellular transport in cell culture models. PMID:23955734

Bressler, Joseph; Clark, Katherine; O'Driscoll, Cliona

2013-01-01

271

Differences in brain function and changes with intervention in children with poor spelling and reading abilities.  

PubMed

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

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

2012-01-01

272

Normalizing hematocrit in dialysis patients improves brain function  

Microsoft Academic Search

Recombinant human erythropoietin (rHuEPO) treatment has been shown to improve brain and cognitive function in anemic dialysis patients. Significant debate continues, however, regarding the appropriate target hematocrit (Hct) that will lead to the greatest benefits while considering possible side effects and costs of rHuEPO. Current practice results in an Hct averaging only 31% to 32% in dialysis patients, a level

Janiece L. Pickett; David C. Theberge; Warren S. Brown; Suzanne U. Schweitzer; Allen R. Nissenson

1999-01-01

273

The Apolipoprotein E Gene, Attention, and Brain Function  

Microsoft Academic Search

The ?4 allele of the apolipoprotein E (ApoE) gene is associated with alterations in brain function and is a risk factor for Alzheimer's disease (AD). Changes in components of visuospatial attention with ApoE-?4, aging, and AD are described. Healthy middle-aged adults without dementia who have the ApoE-?4 gene show deficits in spatial attention and working memory that are qualitatively similar

Raja Parasuraman; Pamela M. Greenwood; Trey Sunderland

2002-01-01

274

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

275

Cluster Structure and Localization of Brain Functional Networks Based on the ERP Signals of Auditory Task  

Microsoft Academic Search

The brain functional networks derived from multi-channel ERP signals are analyzed based on the phase synchronization theory. The nodes of brain functional networks are represented by the channels of ERP signals, and the connectivity of brain functional networks is described by the interaction among the channels. The edge between two different channels exists only if the phase coupling index is

Zhao Zhuo; Shi-Min Cai; Zhong-Qian Fu; Pei-Ling Zhou

2010-01-01

276

This is Your Brain on Interfaces: Enhancing Usability Testing with Functional Near-Infrared Spectroscopy  

E-print Network

This is Your Brain on Interfaces: Enhancing Usability Testing with Functional Near a non-invasive brain sensing technique called functional near infrared spectroscopy (fNIRS) to record it in functional terms as: The load placed on various cogni- tive resources in the brain in order to complete

Jacob, Robert J.K.

277

Atypical Brain Responses to Sounds in Children with Specific Language and Reading Impairments  

ERIC Educational Resources Information Center

This study tested if children with specific language impairment (SLI) or children with specific reading disability (SRD) have abnormal brain responses to sounds. We tested 6- to 12-year-old children with SLI (N = 19), children with SRD (N = 55), and age-matched controls (N = 36) for their passive auditory event-related potentials (ERPs) to tones,…

McArthur, Genevieve; Atkinson, Carmen; Ellis, Danielle

2009-01-01

278

Autism-specific maternal autoantibodies recognize critical proteins in developing brain  

E-print Network

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

Cai, Long

279

Brain basis of early parent–infant interactions: psychology, physiology, and in vivo functional neuroimaging studies  

PubMed Central

Parenting behavior critically shapes human infants’ current and future behavior. The parent–infant relationship provides infants with their first social experiences, forming templates of what they can expect from others and how to best meet others’ expectations. In this review, we focus on the neurobiology of parenting behavior, including our own functional magnetic resonance imaging (fMRI) brain imaging experiments of parents. We begin with a discussion of background, perspectives and caveats for considering the neurobiology of parent–infant relationships. Then, we discuss aspects of the psychology of parenting that are significantly motivating some of the more basic neuroscience research. Following that, we discuss some of the neurohormones that are important for the regulation of social bonding, and the dysregulation of parenting with cocaine abuse. Then, we review the brain circuitry underlying parenting, proceeding from relevant rodent and nonhuman primate research to human work. Finally, we focus on a study-by-study review of functional neuroimaging studies in humans. Taken together, this research suggests that networks of highly conserved hypothalamic–midbrain–limbic–paralimbic–cortical circuits act in concert to support aspects of parent response to infants, including the emotion, attention, motivation, empathy, decision-making and other thinking that are required to navigate the complexities of parenting. Specifically, infant stimuli activate basal forebrain regions, which regulate brain circuits that handle specific nurturing and caregiving responses and activate the brain’s more general circuitry for handling emotions, motivation, attention, and empathy – all of which are crucial for effective parenting. We argue that an integrated understanding of the brain basis of parenting has profound implications for mental health. PMID:17355399

Swain, James E.; Lorberbaum, Jeffrey P.; Kose, Samet; Strathearn, Lane

2015-01-01

280

Functional connectivity and alterations in baseline brain state in humans  

PubMed Central

This work examines the influence of changes in baseline activity on the intrinsic functional connectivity fMRI (fc-fMRI) in humans. Baseline brain activity was altered by inducing anesthesia (sevoflurane end-tidal concentration 1%) in human volunteers and fc-fMRI maps between the pre-anesthetized and anesthetized conditions were compared across different brain networks. We particularly focused on low-level sensory areas (primary somatosensory, visual, auditory cortices), the thalamus, and pain (insula), memory (hippocampus) circuits, and the default mode network (DMN), the latter three to examine higher order brain regions. The results indicate that, while fc-fMRI patterns did not significantly differ (p<0.005; 20-voxel cluster threshold) in sensory cortex and in the DMN between the pre- and anesthetized conditions, fc-fMRI in high-order cognitive regions (i.e. memory and pain circuits) was significantly altered by anesthesia. These findings provide further evidence that fc-fMRI reflects intrinsic brain properties, while also demonstrating that 0.5 MAC sevoflurane anesthesia preferentially modulates higher-order connections. PMID:19631277

Martuzzi, Roberto; Ramani, Ramachandran; Qiu, Maolin; Rajeevan, Nallakkandi; Constable, R. Todd

2009-01-01

281

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

E-print Network

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

Boulanger, Lisa

282

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

283

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. PMID:24660024

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

2014-01-01

284

Kappa-opioid receptor signaling and brain reward function  

PubMed Central

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

Bruijnzeel, Adrie W.

2009-01-01

285

Functional transcranial brain imaging by optical-resolution photoacoustic microscopy  

NASA Astrophysics Data System (ADS)

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

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

2009-07-01

286

The effects of methylphenidate on whole brain intrinsic functional connectivity.  

PubMed

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

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

2014-11-01

287

Heritability of human brain functioning as assessed by electroencephalography  

SciTech Connect

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 heritabilities 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. 44 refs., 5 figs., 4 tabs.

Beijsterveldt, C.E.M. van; Geus, E.J.C. de; Boomsma, D.I. [and others

1996-03-01

288

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. PMID:8644716

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

1996-01-01

289

Interhemispheric functional connectivity following pre- or perinatal brain injury predicts receptive language outcome  

PubMed Central

Early brain injury alters both structural and functional connectivity between the cerebral hemispheres. Despite increasing knowledge on the individual hemispheric contributions to recovery from such injury, we know very little about how their interactions affect this process. In the present study, we related interhemispheric structural and functional connectivity to receptive language outcome following early left hemisphere stroke. We used functional magnetic resonance imaging to study 14 people with neonatal brain injury, and 25 age-matched controls during passive story comprehension. With respect to structural connectivity, we found that increased volume of the corpus callosum predicted good receptive language outcome, but that this is not specific to people with injury. By contrast, we found that increased posterior superior temporal gyrus interhemispheric functional connectivity during story comprehension predicted better receptive language performance in people with early brain injury, but worse performance in typical controls. This suggests that interhemispheric functional connectivity is one potential compensatory mechanism following early injury. Further, this pattern of results suggests refinement of the prevailing notion that better language outcome following early left hemisphere injury relies on the contribution of the contralesional hemisphere (i.e., the “right-hemisphere-take-over” theory). This pattern of results was also regionally specific; connectivity of the angular gyrus predicted poorer performance in both groups, independent of brain injury. These results present a complex picture of recovery—in some cases, such recovery relies on increased cooperation between the injured hemisphere and homologous regions in the contralesional hemisphere, but in other cases, the opposite appears to hold. PMID:23536076

Dick, Anthony Steven; Beharelle, Anjali Raja; Solodkin, Ana; Small, Steven L.

2013-01-01

290

Specific receptors for synthetic GH secretagogues in the human brain and pituitary gland  

Microsoft Academic Search

In vitro studies have been performed to demonstrate and characterize specific binding sites for synthetic GH secre- tagogues (sGHS) on membranes from pituitary gland and diVerent human brain regions. A binding assay for sGHS was established using a peptidyl sGHS (Tyr-Ala-hexarelin) which had been radioiodinated to high specific activity at the Tyr residue. Specific binding sites for 125I-labelled Tyr-Ala-hexarelin were

G Muccioli; C Ghe; M C Ghigo; M Papotti; E Arvat; M F Boghen; MHL Nilsson; R Deghenghi; H Ong; E Ghigo

1998-01-01

291

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

PubMed Central

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

2011-01-01

292

Regional specific regulation of steroid receptor coactivator-1 immunoreactivity by orchidectomy in the brain of adult male mice.  

PubMed

Androgens including testosterone and dihydrotestosterone play important roles on brain structure and function, either directly through androgen receptor or indirectly through estrogen receptors, which need coactivators for their transcription activation. Steroid receptor coactivator-1 (SRC-1) has been shown to be multifunctional potentials in the brain, but how it is regulated by androgens in the brain remains unclear. In this study, we explored the effect of orchidectomy (ORX) on the expression of SRC-1 in the adult male mice using nickel-intensified immunohistochemistry. The results showed that ORX induced dramatic decrease of SRC-1 immunoreactivity in the olfactory tubercle, piriform cortex, ventral pallidum, most parts of the septal area, hippocampus, substantia nigra (compact part), pontine nuclei and nucleus of the trapezoid body (p<0.01). Significant decrease of SRC-1 was noticed in the dorsal and lateral septal nucleus, medial preoptical area, dorsomedial and ventromedial hypothalamic nucleus and superior paraolivary nucleus (p<0.05). Whereas in other regions examined, levels of SRC-1 immunoreactivity were not obviously changed by ORX (p>0.05). The above results demonstrated ORX downregulation of SRC-1 in specific regions that have been involved in sense of smell, learning and memory, cognition, neuroendocrine, reproduction and motor control, indicating that SRC-1 play pivotal role in the mediating circulating androgenic regulation on these important brain functions. It also indicates that SRC-1 may serve as a novel target for the central disorders caused by the age-related decrease of circulating androgens. PMID:24945110

Bian, Chen; Zhang, Kaiyuan; Zhao, Yangang; Guo, Qiang; Cai, Wenqin; Zhang, Jiqiang

2014-10-01

293

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

PubMed Central

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

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

2010-01-01

294

Sleep-disordered breathing: effects on brain structure and function  

PubMed Central

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

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

2013-01-01

295

Constructing Human Brain-Function Association Models from fMRI Literature  

Microsoft Academic Search

Toward the goal of understanding the human brain function, we have developed a web-based human brain functional mapping knowledge base (HBFMKB) system to mining human brain-function association model from vast Medline abstracts. Since nomenclature and relationships among cognitive functions have no consensus yet, we use rule-based natural language processing methods to extract behavioral task and cognitive function and do n-gram

Mei-Yu Hsiao; Der-Yow Chen; Jyh-Horng Chen

2007-01-01

296

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

E-print Network

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

297

Hubs of brain functional networks are radically reorganized in comatose patients  

E-print Network

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

Boyer, Edmond

298

Predictive Modeling of fMRI Brain States using Functional Canonical Correlation Analysis  

E-print Network

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

Smeulders, Arnold

299

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

Microsoft Academic Search

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

Eveline Astrid de Bruin

2005-01-01

300

Studying brain function with near-infrared spectroscopy concurrently with electroencephalography  

E-print Network

Studying brain function with near-infrared spectroscopy concurrently with electroencephalography Y an electroencephalography (EEG) standard multi-channel cap, we can perform functional brain mapping of hemodynamic response-infrared spectroscopy, electroencephalography, evoked potentials, brain imaging 1. INTRODUCTION NIRS and EEG are non

Fantini, Sergio

301

Patient-specific semi-supervised learning for postoperative brain tumor segmentation.  

PubMed

In contrast to preoperative brain tumor segmentation, the problem of postoperative brain tumor segmentation has been rarely approached so far. We present a fully-automatic segmentation method using multimodal magnetic resonance image data and patient-specific semi-supervised learning. The idea behind our semi-supervised approach is to effectively fuse information from both pre- and postoperative image data of the same patient to improve segmentation of the postoperative image. We pose image segmentation as a classification problem and solve it by adopting a semi-supervised decision forest. The method is evaluated on a cohort of 10 high-grade glioma patients, with segmentation performance and computation time comparable or superior to a state-of-the-art brain tumor segmentation method. Moreover, our results confirm that the inclusion of preoperative MR images lead to a better performance regarding postoperative brain tumor segmentation. PMID:25333182

Meier, Raphael; Bauer, Stefan; Slotboom, Johannes; Wiest, Roland; Reyes, Mauricio

2014-01-01

302

Multivariate classification of social anxiety disorder using whole brain functional connectivity.  

PubMed

Recent research has shown that social anxiety disorder (SAD) is accompanied by abnormalities in brain functional connections. However, these findings are based on group comparisons, and, therefore, little is known about whether functional connections could be used in the diagnosis of an individual patient with SAD. Here, we explored the potential of the functional connectivity to be used for SAD diagnosis. Twenty patients with SAD and 20 healthy controls were scanned using resting-state functional magnetic resonance imaging. The whole brain was divided into 116 regions based on automated anatomical labeling atlas. The functional connectivity between each pair of regions was computed using Pearson's correlation coefficient and used as classification feature. Multivariate pattern analysis was then used to classify patients from healthy controls. The pattern classifier was designed using linear support vector machine. Experimental results showed a correct classification rate of 82.5 % (p < 0.001) with sensitivity of 85.0 % and specificity of 80.0 %, using a leave-one-out cross-validation method. It was found that the consensus connections used to distinguish SAD were largely located within or across the default mode network, visual network, sensory-motor network, affective network, and cerebellar regions. Specifically, the right orbitofrontal region exhibited the highest weight in classification. The current study demonstrated that functional connectivity had good diagnostic potential for SAD, thus providing evidence for the possible use of whole brain functional connectivity as a complementary tool in clinical diagnosis. In addition, this study confirmed previous work and described novel pathophysiological mechanisms of SAD. PMID:24072164

Liu, Feng; Guo, Wenbin; Fouche, Jean-Paul; Wang, Yifeng; Wang, Wenqin; Ding, Jurong; Zeng, Ling; Qiu, Changjian; Gong, Qiyong; Zhang, Wei; Chen, Huafu

2015-01-01

303

Highly automated computer-aided diagnosis of neurological disorders using functional brain imaging  

NASA Astrophysics Data System (ADS)

We have implemented a highly automated analytical method for computer aided diagnosis (CAD) of neurological disorders using functional brain imaging that is based on the Scaled Subprofile Model (SSM). Accurate diagnosis of functional brain disorders such as Parkinson's disease is often difficult clinically, particularly in early stages. Using principal component analysis (PCA) in conjunction with SSM on brain images of patients and normals, we can identify characteristic abnormal network covariance patterns which provide a subject dependent scalar score that not only discriminates a particular disease but also correlates with independent measures of disease severity. These patterns represent disease-specific brain networks that have been shown to be highly reproducible in distinct groups of patients. Topographic Profile Rating (TPR) is a reverse SSM computational algorithm that can be used to determine subject scores for new patients on a prospective basis. In our implementation, reference values for a full range of patients and controls are automatically accessed for comparison. We also implemented an automated recalibration step to produce reference scores for images generated in a different imaging environment from that used in the initial network derivation. New subjects under the same setting can then be evaluated individually and a simple report is generated indicating the subject's classification. For scores near the normal limits, additional criteria are used to make a definitive diagnosis. With further refinement, automated TPR can be used to efficiently assess disease severity, monitor disease progression and evaluate treatment efficacy.

Spetsieris, P. G.; Ma, Y.; Dhawan, V.; Moeller, J. R.; Eidelberg, D.

2006-03-01

304

Microinfarcts, brain atrophy, and cognitive function: the HAAS autopsy study  

PubMed Central

Objectives To study the association of microinfarcts (MBI) to ante-mortem global cognitive function (CF), and to investigate whether brain weight (BW), Alzheimer’s lesions (neurofibrillary tangles (NFT) or neuritic plaques (NP) mediate the association. Methods Subjects are 437 well-characterized male decedents from the Honolulu Asia Aging Autopsy Study. Brain pathology was ascertained with standardized methods, CF was measured by the Cognitive Abilities Screening Instrument (CASI)and data were analyzed using formal mediation analyses, adjusted for age at death, time between last CF measure and death, education, and head size. Based on ante-mortem diagnoses, demented and non-demented subjects were examined together and separately. Results In those with no dementia, MBI were strongly associated with the last ante-mortem CF score; this was significantly mediated by BW, and not NFT or NP. In contrast, among those with an ante-mortem diagnosis of dementia, NFT had the strongest associations with BW and with CF, and MIB were modestly associated with CF. Interpretation This suggests microinfarct pathology is a significant and independent factor contributing to brain atrophy and cognitive impairment, particularly before dementia is clinically evident. The role of vascular damage as initiator, stimulator, or additive contributor to neurodegeneration may differ depending on when in the trajectory towards dementia the lesions develop. PMID:22162060

Launer, Lenore J; Hughes, Timothy M; White, Lon R

2011-01-01

305

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

306

Operating Characteristics of Executive Functioning Tests Following Traumatic Brain Injury  

PubMed Central

The primary purposes of this study were to determine if controls, mild, and moderate/severe traumatic brain injury (TBI) patients performed differently on a battery of executive functioning (EF) tests, and to identify the operating characteristics of EF tests in this population. Participants consisted of 46 brain injured individuals and 24 healthy controls. All participants completed an extensive battery of EF tests. Results showed that mild TBI participants performed worse than controls on the Trail Making Test Part B, and that moderate/severe TBI participants consistently performed worse than either group on a variety of EF measures. Tests of EF exhibited a wide range of operating characteristics, suggesting that some EF tests are better than others in identifying TBI-related neurocognitive impairment. Predictive values were better for individuals with moderate/severe TBI than mild TBI. Overall, the Digit Span Backward Test showed the best positive predictive power in differentiating TBI. Our results provide useful data that may guide test selection in evaluating EF in patients with traumatic brain injury. PMID:21069617

Demery, Jason A.; Larson, Michael J.; Dixit, Neha K.; Bauerand, Russell M.; Perlstein, William M.

2010-01-01

307

Functional brain mapping during free viewing of natural scenes  

Microsoft Academic Search

Previous imaging studies have used mostly perceptually abstracted, idealized, or static stimuli to show segregation of function in the cerebral cortex. We wanted to learn whether functional segregation is maintained during more natural, complex, and dynamic conditions when many features have to be processed simultaneously, and identify regions whose activity correlates with the perception of specific features. To achieve this,

Andreas Bartels; Semir Zeki

2004-01-01

308

Brain function in patients with cerebral fat embolism evaluated using somatosensory and brain-stem auditory evoked potentials  

Microsoft Academic Search

In two victims of traffic accidents with broken bones and fat embolism, serial recordings of somatosensory evoked potentials (SEPs) and brain-stem auditory evoked potentials (BAEPs) were examined to assess brain function. Initial SEPs and BAEPs revealed normal subcortical components, while the late cortical components of SEPs were abolished, findings indicative of diffuse dysfunction of grey rather than of white matter.

T. Morioka; H. Yagi

1989-01-01

309

Delta opioid receptors in brain function and diseases  

PubMed Central

Evidence that the delta opioid receptor (DOR) is an attractive target for the treatment of brain disorders has strengthened in recent years. This receptor is broadly expressed in the brain, binds endogenous opioid peptides, and shows as functional profile highly distinct from those of mu and kappa opioid receptors. Our knowledge of DOR function has enormously progressed from in vivo studies using pharmacological tools and genetic approaches. The important role of this receptor in reducing chronic pain has been extensively overviewed; therefore this review focuses on facets of delta receptor activity relevant to psychiatric and other neurological disorders. Beneficial effects of DOR agonists are now well established in the context of emotional responses and mood disorders. DOR activation also regulates drug reward, inhibitory controls and learning processes, but whether delta compounds may represent useful drugs in the treatment of drug abuse remains open. Epileptogenic and locomotor-stimulating effects of delta agonists appear drug-dependent, and the possibility of biased agonism at DOR for these effects is worthwhile further investigations to increase benefit/risk ratio of delta therapies. Neuroprotective effects of DOR activity represent a forthcoming research area. Future developments in DOR research will benefit from in-depth investigations of DOR function at cellular and circuit levels. PMID:23764370

Chung, Paul Chu Sin; Kieffer, Brigitte L.

2013-01-01

310

Delta opioid receptors in brain function and diseases.  

PubMed

Evidence that the delta opioid receptor (DOR) is an attractive target for the treatment of brain disorders has strengthened in recent years. This receptor is broadly expressed in the brain, binds endogenous opioid peptides, and shows as functional profile highly distinct from those of mu and kappa opioid receptors. Our knowledge of DOR function has enormously progressed from in vivo studies using pharmacological tools and genetic approaches. The important role of this receptor in reducing chronic pain has been extensively overviewed; therefore this review focuses on facets of delta receptor activity relevant to psychiatric and other neurological disorders. Beneficial effects of DOR agonists are now well established in the context of emotional responses and mood disorders. DOR activation also regulates drug reward, inhibitory controls and learning processes, but whether delta compounds may represent useful drugs in the treatment of drug abuse remains open. Epileptogenic and locomotor-stimulating effects of delta agonists appear drug-dependent, and the possibility of biased agonism at DOR for these effects is worthwhile further investigations to increase benefit/risk ratio of delta therapies. Neuroprotective effects of DOR activity represent a forthcoming research area. Future developments in DOR research will benefit from in-depth investigations of DOR function at cellular and circuit levels. PMID:23764370

Chu Sin Chung, Paul; Kieffer, Brigitte L

2013-10-01

311

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. PMID:17874302

Oscar-Berman, Marlene; Marinkovi?, Ksenija

2014-01-01

312

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. PMID:24179218

Turk-Browne, Nicholas B.

2014-01-01

313

Relationship between specific gravity, water content, and serum protein extravasation in various types of vasogenic brain edema  

Microsoft Academic Search

Vasogenic brain edema was induced in cats by cold injury (six animals), brain tumors (five animals), and brain abscesses (six animals). Water and electrolyte content, specific gravity, blood volume, and the amount of extravasated serum proteins were determined in small tissue samples taken from gray and white matter at various distances from the lesion. Edema was strictly confined to the

H.-W. Bothe; W. Bodsch; K.-A. Hossmann

1984-01-01

314

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

PubMed Central

Central nervous system (CNS) diseases represent the largest and fastest growing area of unmet medical need. Nanotechnology plays a unique instrumental role in the revolutionary development of brain-specific drug delivery, imaging, and diagnosis. With the aid of nanoparticles of high specificity and multifunctionality, such as dendrimers and quantum dots, therapeutics, imaging agents, and diagnostic molecules can be delivered to the brain across the blood-brain barrier (BBB), enabling considerable progress in the understanding, diagnosis, and treatment of CNS diseases. Nanoparticles used in the CNS for drug delivery, imaging, and diagnosis are reviewed, as well as their administration routes, toxicity, and routes to cross the BBB. Future directions and major challenges are outlined. PMID:20593303

Yang, Hu

2010-01-01

315

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. PMID:25011478

2014-01-01

316

Changes in brain functional network connectivity after stroke.  

PubMed

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

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

2014-01-01

317

Neutralizing anti-interleukin-1? antibodies modulate fetal blood-brain barrier function after ischemia.  

PubMed

We have previously shown that increases in blood-brain barrier permeability represent an important component of ischemia-reperfusion related brain injury in the fetus. Pro-inflammatory cytokines could contribute to these abnormalities in blood-brain barrier function. We have generated pharmacological quantities of mouse anti-ovine interleukin-1? monoclonal antibody and shown that this antibody has very high sensitivity and specificity for interleukin-1? protein. This antibody also neutralizes the effects of interleukin-1? protein in vitro. In the current study, we hypothesized that the neutralizing anti-interleukin-1? monoclonal antibody attenuates ischemia-reperfusion related fetal blood-brain barrier dysfunction. Instrumented ovine fetuses at 127 days of gestation were studied after 30 min of carotid occlusion and 24h of reperfusion. Groups were sham operated placebo-control- (n=5), ischemia-placebo- (n=6), ischemia-anti-IL-1? antibody- (n=7), and sham-control antibody- (n=2) treated animals. Systemic infusions of placebo (0.154M NaCl) or anti-interleukin-1? monoclonal antibody (5.1±0.6 mg/kg) were given intravenously to the same sham or ischemic group of fetuses at 15 min and 4h after ischemia. Concentrations of interleukin-1? protein and anti-interleukin-1? monoclonal antibody were measured by ELISA in fetal plasma, cerebrospinal fluid, and parietal cerebral cortex. Blood-brain barrier permeability was quantified using the blood-to-brain transfer constant (Ki) with ?-aminoisobutyric acid in multiple brain regions. Interleukin-1? protein was also measured in parietal cerebral cortices and tight junction proteins in multiple brain regions by Western immunoblot. Cerebral cortical interleukin-1? protein increased (P<0.001) after ischemia-reperfusion. After anti-interleukin-1? monoclonal antibody infusions, plasma anti-interleukin-1? monoclonal antibody was elevated (P<0.001), brain anti-interleukin-1? monoclonal antibody levels were higher (P<0.03), and interleukin-1? protein concentrations (P<0.03) and protein expressions (P<0.001) were lower in the monoclonal antibody-treated group than in placebo-treated-ischemia-reperfusion group. Monoclonal antibody infusions attenuated ischemia-reperfusion-related increases in Ki across the brain regions (P<0.04), and Ki showed an inverse linear correlation (r= -0.65, P<0.02) with anti-interleukin-1? monoclonal antibody concentrations in the parietal cortex, but had little effect on tight junction protein expression. We conclude that systemic anti-interleukin-1? monoclonal antibody infusions after ischemia result in brain anti-interleukin-1? antibody uptake, and attenuate ischemia-reperfusion-related interleukin-1? protein up-regulation and increases in blood-brain barrier permeability across brain regions in the fetus. The pro-inflammatory cytokine, interleukin-1?, contributes to impaired blood-brain barrier function after ischemia in the fetus. PMID:25258170

Chen, Xiaodi; Sadowska, Grazyna B; Zhang, Jiyong; Kim, Jeong-Eun; Cummings, Erin E; Bodge, Courtney A; Lim, Yow-Pin; Makeyev, Oleksandr; Besio, Walter G; Gaitanis, John; Threlkeld, Steven W; Banks, William A; Stonestreet, Barbara S

2015-01-01

318

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

PubMed

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

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

2010-09-01

319

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

ERIC Educational Resources Information Center

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

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

2006-01-01

320

Food for thought: the importance of glucose and other energy substrates for sustaining brain function under varying levels of activity  

Microsoft Academic Search

The brain requires a constant and substantial energy supply to maintain its main functions. For decades, it was assumed that glucose was the major if not the only significant source of energy for neurons. This view was supported by the expression of specific facilitative glucose transporters on cerebral blood vessels, as well as neurons. Despite the fact that glucose remains

L. Pellerin

2010-01-01

321

Cloning and Functional Characterization of a Family of Human and Mouse Somatostatin Receptors Expressed in Brain, Gastrointestinal Tract, and Kidney  

Microsoft Academic Search

Somatostatin is a tetradecapeptide that is widely distributed in the body. It acts on multiple organs including brain, pituitary, gut, exocrine and endocrine pancreas, adrenals, thyroid, and kidneys to inhibit release of many hormones and other secretory proteins. In addition, it functions as a neuropeptide affecting the electrical activity of neurons. Somatostatin exerts its biological effects by binding to specific

Yuichiro Yamada; Steven R. Post; Kenneth Wang; Howard S. Tager; Graeme I. Bell; Susumu Seino

1992-01-01

322

Functional design specification: NASA form 1510  

NASA Technical Reports Server (NTRS)

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

1979-01-01

323

Fetal functional imaging portrays heterogeneous development of emerging human brain networks  

PubMed Central

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

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

2014-01-01

324

Brain site-specific proteome changes in aging-related dementia  

PubMed Central

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

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

2013-01-01

325

Functional Tissue Pulsatility Imaging of the Brain during Visual Stimulation  

PubMed Central

Functional tissue pulsatility imaging (fTPI) is a new ultrasonic technique being developed to map brain function by measuring changes in tissue pulsatility due to changes in blood flow with neuronal activation. The technique is based in principle on plethysmography, an older, non-ultrasound technology for measuring expansion of a whole limb or body part due to perfusion. Perfused tissue expands by a fraction of a percent early in each cardiac cycle when arterial inflow exceeds venous outflow and relaxes later in the cardiac cycle when venous drainage dominates. Tissue pulsatility imaging (TPI) uses tissue Doppler signal processing methods to measure this pulsatile “plethysmographic” signal from hundreds or thousands of sample volumes in an ultrasound image plane. A feasibility study was conducted to determine if TPI could be used to detect regional brain activation during a visual contrast-reversing checkerboard block paradigm study. During a study, ultrasound data were collected transcranially from the occipital lobe as a subject viewed alternating blocks of a reversing checkerboard (stimulus condition) and a static, gray screen (control condition). Multivariate Analysis of Variance (MANOVA) was used to identify sample volumes with significantly different pulsatility waveforms during the control and stimulus blocks. In 7 out 14 studies, consistent regions of activation were detected from tissue around the major vessels perfusing the visual cortex. PMID:17346872

Kucewicz, John C.; Dunmire, Barbrina; Leotta, Daniel F.; Panagiotides, Heracles; Paun, Marla; Beach, Kirk W.

2007-01-01

326

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

E-print Network

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

Mueller, Klaus

327

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

E-print Network

Associated with Spontaneous Fluctuations of Intensity of Chronic Back Pain Marwan N. Baliki,1 Dante R,yetthereisalackofknowledgeregardingbrainelementsinvolvedinsuchconditions.Here,weidentifybrainregionsinvolvedin spontaneous pain of chronic back pain (CBP) in two separate groups of patients (n 13 and n 11), and contrast, specifically in chronic back pain (CBP). Chronic pain is often associated with spontaneous pain (pain

Apkarian, A. Vania

328

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. PMID:23684971

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

2013-01-01

329

Functionalized nanoscale micelles with brain targeting ability and intercellular microenvironment biosensitivity for anti-intracranial infection applications.  

PubMed

Due to complication factors such as blood-brain barrier (BBB), integrating high efficiency of brain target ability with specific cargo releasing into one nanocarrier seems more important. A brain targeting nanoscale system is developed using dehydroascorbic acid (DHA) as targeting moiety. DHA has high affinity with GLUT1 on BBB. More importantly, the GLUT1 transportation of DHA represents a "one-way" accumulative priority from blood into brain. The artificial micelles are fabricated by a disulfide linkage, forming a bio-responsive inner barrier, which can maintain micelles highly stable in circulation and shield the leakage of entrapped drug before reaching the targeting cells. The designed micelles can cross BBB and be further internalized by brain cells. Once within the cells, the drug release can be triggered by high intracellular level of glutathione (GSH). Itraconazole (ITZ) is selected as the model drug because of its poor brain permeability and low stability in blood. It demonstrates that the functionalized nanoscale micelles can achieve highly effective direct drug delivery to targeting site. Based on the markedly increased stability in blood circulation and improved brain delivery efficiency of ITZ, DHA-modified micelles show highly effective in anti-intracranial infection. Therefore, this smart nanodevice shows a promising application for the treatment of brain diseases. PMID:25124929

Shao, Kun; Zhang, Yu; Ding, Ning; Huang, Shixian; Wu, Jiqin; Li, Jianfeng; Yang, Chunfu; Leng, Qibin; Ye, Liya; Lou, Jinning; Zhu, Liping; Jiang, Chen

2015-01-01

330

Widespread Disruption of Functional Brain Organization in Early-Onset Alzheimer’s Disease  

PubMed Central

Early-onset Alzheimer’s disease (AD) patients present a different clinical profile than late-onset AD patients. This can be partially explained by cortical atrophy, although brain organization might provide more insight. The aim of this study was to examine functional connectivity in early-onset and late-onset AD patients. Resting-state fMRI scans of 20 early-onset (<65 years old), 28 late-onset (?65 years old) AD patients and 15 “young” (<65 years old) and 31 “old” (?65 years old) age-matched controls were available. Resting-state network-masks were used to create subject-specific maps. Group differences were examined using a non-parametric permutation test, accounting for gray-matter. Performance on five cognitive domains were used in a correlation analysis with functional connectivity in AD patients. Functional connectivity was not different in any of the RSNs when comparing the two control groups (young vs. old controls), which implies that there is no general effect of aging on functional connectivity. Functional connectivity in early-onset AD was lower in all networks compared to age-matched controls, where late-onset AD showed lower functional connectivity in the default-mode network. Functional connectivity was lower in early-onset compared to late-onset AD in auditory-, sensory-motor, dorsal-visual systems and the default mode network. Across patients, an association of functional connectivity of the default mode network was found with visuoconstruction. Functional connectivity of the right dorsal visual system was associated with attention across patients. In late-onset AD patients alone, higher functional connectivity of the sensory-motor system was associated with poorer memory performance. Functional brain organization was more widely disrupted in early-onset AD when compared to late-onset AD. This could possibly explain different clinical profiles, although more research into the relationship of functional connectivity and cognitive performance is needed. PMID:25080229

Adriaanse, Sofie M.; Binnewijzend, Maja A. A.; Ossenkoppele, Rik; Tijms, Betty M.; van der Flier, Wiesje M.; Koene, Teddy; Smits, Lieke L.; Wink, Alle Meije; Scheltens, Philip; van Berckel, Bart N. M.; Barkhof, Frederik

2014-01-01

331

Functional Brain Correlates of Upper Limb Spasticity and Its Mitigation following Rehabilitation in Chronic Stroke Survivors.  

PubMed

Background. Arm spasticity is a challenge in the care of chronic stroke survivors with motor deficits. In order to advance spasticity treatments, a better understanding of the mechanism of spasticity-related neuroplasticity is needed. Objective. To investigate brain function correlates of spasticity in chronic stroke and to identify specific regional functional brain changes related to rehabilitation-induced mitigation of spasticity. Methods. 23 stroke survivors (>6 months) were treated with an arm motor learning and spasticity therapy (5?d/wk for 12 weeks). Outcome measures included Modified Ashworth scale, sensory tests, and functional magnetic resonance imaging (fMRI) for wrist and hand movement. Results. First, at baseline, greater spasticity correlated with poorer motor function (P = 0.001) and greater sensory deficits (P = 0.003). Second, rehabilitation produced improvement in upper limb spasticity and motor function (P < 0.0001). Third, at baseline, greater spasticity correlated with higher fMRI activation in the ipsilesional thalamus (rho = 0.49, P = 0.03). Fourth, following rehabilitation, greater mitigation of spasticity correlated with enhanced fMRI activation in the contralesional primary motor (r = -0.755, P = 0.003), premotor (r = -0.565, P = 0.04), primary sensory (r = -0.614, P = 0.03), and associative sensory (r = -0.597, P = 0.03) regions while controlling for changes in motor function. Conclusions. Contralesional motor regions may contribute to restoring control of muscle tone in chronic stroke. PMID:25101190

Pundik, Svetlana; Falchook, Adam D; McCabe, Jessica; Litinas, Krisanne; Daly, Janis J

2014-01-01

332

Minimal brain dysfunction/specific learning disability: a clinical approach for the primary physician.  

PubMed

Minimal brain dysfunction is a neurodevelopmental disorder which can be found in nearly 20% of school children. It is characterized by evidences of immaturity involving control of activity, emotions, and behavior, and by specific learning disabilities involving the communicating skills needed in reading, writing, and mathematics. The prime deficits in the classroom are an inability to maintain attention and concentration and an inability to skillfully blend the auditory and visual functions essential in language performance. Medical evaluation will reveal many of the "soft signs" of neurologic involvement, and educational appraisal will indicate a wide scatter in testing scores with a marked discrepancy between evaluated potential and actual classroom achievement. Remedial efforts directed at early detection, relief from pressure and unjust punishment or ridicule from parents and teachers, and adjustment of the educational environment with consideration of the child's individual talents, combined with the judicious use of medications to prolong attention span and improve neurodevelopmental maturity, hold promise of improving the lot of most involved children. There are valid indications that expansion of such programs can do much to prevent these youngsters from developing severe personality maladjustment and delinquent behavior, as well as emotional illness in later life. PMID:1273628

Levy, H B

1976-05-01

333

Specific in vivo staining of astrocytes in the whole brain after intravenous injection of sulforhodamine dyes.  

PubMed

Fluorescent staining of astrocytes without damaging or interfering with normal brain functions is essential for intravital microscopy studies. Current methods involved either transgenic mice or local intracerebral injection of sulforhodamine 101. Transgenic rat models rarely exist, and in mice, a backcross with GFAP transgenic mice may be difficult. Local injections of fluorescent dyes are invasive. Here, we propose a non-invasive, specific and ubiquitous method to stain astrocytes in vivo. This method is based on iv injection of sulforhodamine dyes and is applicable on rats and mice from postnatal age to adulthood. The astrocytes staining obtained after iv injection was maintained for nearly half a day and showed no adverse reaction on astrocytic calcium signals or electroencephalographic recordings in vivo. The high contrast of the staining facilitates the image processing and allows to quantify 3D morphological parameters of the astrocytes and to characterize their network. Our method may become a reference for in vivo staining of the whole astrocytes population in animal models of neurological disorders. PMID:22509398

Appaix, Florence; Girod, Sabine; Boisseau, Sylvie; Römer, Johannes; Vial, Jean-Claude; Albrieux, Mireille; Maurin, Mathieu; Depaulis, Antoine; Guillemain, Isabelle; van der Sanden, Boudewijn

2012-01-01

334

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

PubMed

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

Xu, Xiaoxiao; Nehorai, Arye; Dougherty, Joseph

2013-07-01

335

Towards the Study of Functional Brain Development in Depression: An Interactive Specialization Approach  

PubMed Central

Depression is a significant and impairing mood disorder with onset possible as early as age 3 and into adulthood. Given this varying pattern of age of onset, identifying the relationship between brain development and depression across the lifespan has proven elusive. This review identifies some of the factors that may have limited the advancement of our knowledge in this area and discusses how synthesizing established models of depression and normative brain development may help to overcome them. More specifically, it is suggested that current neurobiological models of depression fail to account for the developmental variance associated with early neural network development and the potential influence of experience on this process. The utility of applying an established framework of normative brain development to this topic is described and its potential utility for conceptualizing the influence of depression on brain function across the life span is addressed. Future directions including longitudinal neuroimaging studies of early onset depression and groups at risk for this disorder are proposed. PMID:22750525

Gaffrey, Michael S.; Luby, Joan L.; Barch, Deanna M.

2012-01-01

336

Function and Dysfunction of Prefrontal Brain Circuitry in Alcoholic Korsakoff’s Syndrome  

PubMed Central

The signature symptom of alcohol-induced persisting amnestic disorder, more commonly referred to as alcoholic Korsakoff’s syndrome (KS), is anterograde amnesia, or memory loss for recent events, and until the mid 20th Century, the putative brain damage was considered to be in diencephalic and medial temporal lobe structures. Overall intelligence, as measured by standardized IQ tests, usually remains intact. Preservation of IQ occurs because memories formed before the onset of prolonged heavy drinking — the types of information and abilities tapped by intelligence tests — remain relatively well preserved compared with memories recently acquired. However, clinical and experimental evidence has shown that neurobehavioral dysfunction in alcoholic patients with KS does include nonmnemonic abilities, and further brain damage involves extensive frontal and limbic circuitries. Among the abnormalities are confabulation, disruption of elements of executive functioning and cognitive control, and emotional impairments. Here, we discuss the relationship between neurobehavioral impairments in KS and alcoholism-related brain damage. More specifically, we examine the role of damage to prefrontal brain systems in the neuropsychological profile of alcoholic KS. PMID:22538385

Oscar-Berman, Marlene

2013-01-01

337

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

PubMed Central

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

Hasler, Brant P.; Clark, Duncan B.

2013-01-01

338

Physiological monitoring of brain function with a broadband multifiber continuous-wave optical system  

NASA Astrophysics Data System (ADS)

An instrument designed for physiological monitoring should be relatively inexpensive, take readings rapidly and be able to discriminate optical signals due to specific chromophores. A cw, broadband, multifiber system can potentially meet these requirements. The use of a steady- state light source rather than making time-resolved or frequency-domain measurements means that the system is relatively inexpensive. Simultaneous detection of signals from multiple optical fibers means that multiple measurements can be made simultaneously. By making broadband measurements it is possible to discriminate amongst the many chromophores which contribute the optical signal. We have developed a cw, broadband, multifiber system and are testing it in vivo. A possible application is noninvasive, optical monitoring of the brain which has the potential to be a real-time, noninvasive method for clinical monitoring as well as being a technique for studying fundamental aspects of brain function.

Mourant, Judith R.; Johnson, Tamara M.; Jack, Darren A.

1997-06-01

339

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

PubMed Central

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

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

2014-01-01

340

Thyroid hormones, brain function and cognition: a brief review  

Microsoft Academic Search

In addition to their role in cellular metabolic activity, thyroid hormones (THs), also regulate neural development; the central nervous system is particularly dependent on TH for normal maturation and function. Specifically, there appears to be extensive inter-reliance between TH and acetylcholine (Ach), nerve growth factor and hippocampal function. These associations led us to investigate the possible effects of thyroxine (L-T4)

Jeremy W. Smith; A. Tudor Evans; B. Costall; James W. Smythe

2002-01-01

341

Desensitization of myocardial ?-adrenergic receptors and deterioration of left ventricular function after brain death  

Microsoft Academic Search

Brain death often results in a series of hemodynamic alterations that complicate the treatment of potential organ donors before transplantation. The deterioration of myocardial performance after brain death has been described; however, the pathophysiologic process of the myocardial dysfunction that occurs after brain death has not been elucidated. This study was designed to analyze the function of the myocardial ?-adrenergic

Thomas A. D'Amico; Cary H. Meyers; Theodore C. Koutlas; David S. Peterseim; David C. Sabiston; Peter Van Trigt; Debra A. Schwinn

1995-01-01

342

Pathophysiological Response to Experimental Diffuse Brain Trauma Differs as a Function of Developmental Age  

Microsoft Academic Search

The purpose of experimental models of traumatic brain injury (TBI) is to reproduce selected aspects of human head injury such as brain edema, contusion or concussion, and functional deficits, among others. As the immature brain may be particularly vulnerable to injury during critical periods of development, and pediatric TBI may cause neurobehavioral deficits, our aim was to develop and characterize

Ibolja Cernak; Taeun Chang; Farid A. Ahmed; Maria I. Cruz; Robert Vink; Bogdan Stoica; Alan I. Faden

2010-01-01

343

Functional Representation of Human Embryo Brain Models Roman Durikovic Silvester Czanner  

E-print Network

Functional Representation of Human Embryo Brain Models Roman Durikovic Silvester Czanner Hirofumi embryo brain is organic and has many folds that are difficult to model or animate with conventional metamorphosis during the growth of some human embryo organs, partic- ularly brain and stomach. Popular methods

Durikovic, Roman

344

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

E-print Network

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

Golland, Polina

345

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

Microsoft Academic Search

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

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

2010-01-01

346

Measuring, mapping, and modeling brain structure and function  

NASA Astrophysics Data System (ADS)

Presently available anatomic atlases provide useful coordinate systems such as the ubiquitous Talairach system but are sorely lacking in both spatial resolution and completeness. An appropriately sampled anatomic specimen can provide the additional detail necessary to accurately localize activation sites as well as provide other structural perspectives such as chemoarchitecture. We collected serial section postmortem anatomic data from several whole human head and brain specimens using a cryosectioning technique. Tissue imaged so that voxel resolution was 200 microns or better at full color. These high resolution datasets along with collections of MR data were placed within a common coordinate system and used to produce a probabilistic representation. This approach represents anatomy within a coordinate system as a probability. Coordinate locations are assigned a confidence limit to describe the likelihood that a given location belongs to an anatomic structure based upon the population of specimens. A variety of warping strategies are discussed to provide statistics on morphometric variability and probability. High dimensional anatomically based warps utilizing sulcal anatomy are described. These data are an important and necessary part of the comprehensive structural and functional analyses that focus on the mapping of the human brain.

Toga, Arthur W.; Thompson, Paul

1997-05-01

347

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

348

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

PubMed

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

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

2014-09-01

349

A genome-wide supported psychiatric risk variant in NCAN influences brain function and cognitive performance in healthy subjects.  

PubMed

The A allele of the single nucleotide polymorphism (SNP) rs1064395 in the NCAN gene has recently been identified as a susceptibility factor for bipolar disorder and schizophrenia. NCAN encodes neurocan, a brain-specific chondroitin sulfate proteoglycan that is thought to influence neuronal adhesion and migration. Several lines of research suggest an impact of NCAN on neurocognitive functioning. In the present study, we investigated the effects of rs1064395 genotype on neural processing and cognitive performance in healthy subjects. Brain activity was measured with functional magnetic resonance imaging (fMRI) during an overt semantic verbal fluency task in 110 healthy subjects who were genotyped for the NCAN SNP rs1064395. Participants additionally underwent comprehensive neuropsychological testing. Whole brain analyses revealed that NCAN risk status, defined as AA or AG genotype, was associated with a lack of task-related deactivation in a large left lateral temporal cluster extending from the middle temporal gyrus to the temporal pole. Regarding neuropsychological measures, risk allele carriers demonstrated poorer immediate and delayed verbal memory performance when compared to subjects with GG genotype. Better verbal memory performance was significantly associated with greater deactivation of the left temporal cluster during the fMRI task in subjects with GG genotype. The current data demonstrate that common genetic variation in NCAN influences both neural processing and cognitive performance in healthy subjects. Our study provides new evidence for a specific genetic influence on human brain function. Hum Brain Mapp, 36:378-390, 2015. © 2014 Wiley Periodicals, Inc. PMID:25220293

Raum, Heidelore; Dietsche, Bruno; Nagels, Arne; Witt, Stephanie H; Rietschel, Marcella; Kircher, Tilo; Krug, Axel

2015-01-01

350

Requirement for interleukin-1 to drive brain inflammation reveals tissue-specific mechanisms of innate immunity.  

PubMed

The immune system is implicated in a wide range of disorders affecting the brain and is, therefore, an attractive target for therapy. Interleukin-1 (IL-1) is a potent regulator of the innate immune system important for host defense but is also associated with injury and disease in the brain. Here, we show that IL-1 is a key mediator driving an innate immune response to inflammatory challenge in the mouse brain but is dispensable in extracerebral tissues including the lung and peritoneum. We also demonstrate that IL-1? is an important ligand contributing to the CNS dependence on IL-1 and that IL-1 derived from the CNS compartment (most likely microglia) is the major source driving this effect. These data reveal previously unknown tissue-specific requirements for IL-1 in driving innate immunity and suggest that IL-1-mediated inflammation in the brain could be selectively targeted without compromising systemic innate immune responses that are important for resistance to infection. This property could be exploited to mitigate injury- and disease-associated inflammation in the brain without increasing susceptibility to systemic infection, an important complication in several neurological disorders. PMID:25367678

Giles, James A; Greenhalgh, Andrew D; Davies, Claire L; Denes, Adam; Shaw, Tovah; Coutts, Graham; Rothwell, Nancy J; McColl, Barry W; Allan, Stuart M

2015-02-01

351

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

PubMed

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

Yuan, Zhen

2013-10-01

352

Effect of tumor resection on the characteristics of functional brain networks  

NASA Astrophysics Data System (ADS)

Brain functioning such as cognitive performance depends on the functional interactions between brain areas, namely, the functional brain networks. The functional brain networks of a group of patients with brain tumors are measured before and after tumor resection. In this work, we perform a weighted network analysis to understand the effect of neurosurgery on the characteristics of functional brain networks. Statistically significant changes in network features have been discovered in the beta (13-30 Hz) band after neurosurgery: the link weight correlation around nodes and within triangles increases which implies improvement in local efficiency of information transfer and robustness; the clustering of high link weights in a subgraph becomes stronger, which enhances the global transport capability; and the decrease in the synchronization or virus spreading threshold, revealed by the increase in the largest eigenvalue of the adjacency matrix, which suggests again the improvement of information dissemination.

Wang, H.; Douw, L.; Hernández, J. M.; Reijneveld, J. C.; Stam, C. J.; van Mieghem, P.

2010-08-01

353

Properties of specific binding site of myotoxin a, a powerful convulsant, in brain microsomes.  

PubMed

Myotoxin a, a small basic polypeptide from prairie rattlesnakes (Crotalus viridis viridis), induces myonecrosis and binds to a single class of binding sites in skeletal muscle sarcoplasmic reticulum. In the present study, [125I]myotoxin a with a high specific activity was prepared and it was shown to bind mainly to microsomes in rat whole brain. [125I]Myotoxin a was further shown to bind to microsomes prepared from all regions tested in brain. Its specific binding to whole brain microsomes was of approximately 1.9 times lower affinity (KD = 0.76 microM; Bmax = 13.1 nmol/mg) than that to skeletal muscle sarcoplasmic reticulum. [125I]Myotoxin a binding to brain microsomes was displaced by unlabeled myotoxin a with an IC50 value of 4.5 microM. [125I]Myotoxin a binding was markedly reduced by treatment of microsomes with trypsin, suggesting that the binding site of [125I]myotoxin a is partially proteins. The binding was significantly inhibited by Mg2+ at concentrations above 1 mM. Having looked at several drugs, we noted that [125I]myotoxin a binding was noncompetitively inhibited by spermine, whereas it was enhanced by heparin. On the other hand, the i.c.v. injection of myotoxin a in mice induced potent convulsive effects at 0.05 nmol/mouse or more. This paper is the first to show that the specific binding site of myotoxin a is present in mouse brain and that myotoxin a is a novel peptidic convulsant in mice. PMID:9795748

Katagiri, C; Ishikawa, H H; Ohkura, M; Nakagawasai, O; Tadano, T; Kisara, K; Ohizumi, Y

1998-04-01

354

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

PubMed Central

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

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

2014-01-01

355

Chemokine receptor CXCR7 is a functional receptor for CXCL12 in brain endothelial cells.  

PubMed

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

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

2014-01-01

356

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

357

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

SciTech Connect

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

Ellison, M.D.B.

1985-01-01

358

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

PubMed Central

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

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

2014-01-01

359

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

PubMed

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

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

2014-01-01

360

Changes in brain functional homogeneity in subjects with Alzheimer's disease  

Microsoft Academic Search

Imaging studies have reported marked reductions in brain glucose metabolism in Alzheimer's Disease (AD). However, less is known about disruptions in the patterns of brain metabolic activity. Here we questioned whether AD affects the patterns of homogeneity\\/heterogeneity in brain metabolism. PET images of 35 AD subjects were compared with those of 35 controls. A template was applied to extract a

Nora D Volkow; Wei Zhu; Christoph A Felder; Klaus Mueller; Tomihisa F Welsh; Gene-Jack Wang; Mony J de Leon

2002-01-01

361

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

PubMed Central

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

Jullienne, Amandine; Badaut, Jérôme

2014-01-01

362

Suicidal brains: A review of functional and structural brain studies in association with suicidal behaviour  

Microsoft Academic Search

Evidence of an association between a vulnerability to suicidal behaviour and neurobiological abnormalities is accumulating. Post-mortem studies have demonstrated structural and biochemical changes in the brains of suicide victims. More recently, imaging techniques have become available to study changes in the brain in vivo. This systematic review of comparative imaging studies of suicidal brains shows that changes in the structure

C. van Heeringen; S. Bijttebier; K. Godfrin

2011-01-01

363

Scalp EEG brain functional connectivity networks in pediatric epilepsy.  

PubMed

This study establishes a new data-driven approach to brain functional connectivity networks using scalp EEG recordings for classifying pediatric subjects with epilepsy from pediatric controls. Graph theory is explored on the functional connectivity networks of individuals where three different sets of topological features were defined and extracted for a thorough assessment of the two groups. The rater's opinion on the diagnosis could also be taken into consideration when deploying the general linear model (GLM) for feature selection in order to optimize classification. Results demonstrate the existence of statistically significant (p<0.05) changes in the functional connectivity of patients with epilepsy compared to those of control subjects. Furthermore, clustering results demonstrate the ability to discriminate pediatric epilepsy patients from control subjects with an initial accuracy of 87.5%, prior to initiating the feature selection process and without taking into consideration the clinical rater's opinion. Otherwise, leave-one-out cross validation (LOOCV) showed a significant increase in the classification accuracy to 96.87% in epilepsy diagnosis. PMID:25464357

Sargolzaei, Saman; Cabrerizo, Mercedes; Goryawala, Mohammed; Eddin, Anas Salah; Adjouadi, Malek

2015-01-01

364

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

PubMed Central

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

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

2013-01-01

365

Neurovascular coupling: in vivo optical techniques for functional brain imaging  

PubMed Central

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

2013-01-01

366

Functional outcomes of community-based brain injury rehabilitation clients.  

PubMed

Abstract Background: Community-based rehabilitation can help to maximize function following acquired brain injury (ABI); however, data on treatment outcome is limited in quantity. Objective: To describe and evaluate client outcomes of an outpatient programme for adults with moderate-to-severe traumatic and non-traumatic ABI. Methods: Two phase design involving retrospective and longitudinal study of programme completers with ABI (n?=?47). Changes in functioning were measured with the Mayo-Portland Inventory (MPAI-4), administered pre- and immediately post-rehabilitation and at 3 years follow-up. Self-ratings were supplemented with MPAI-4 data from significant others (n?=?32) and staff (n?=?32). Results: Injured individuals and informants reported improved physical and psychosocial functioning immediately following the completion of community rehabilitation, with medium-to-large and significant treatment gains noted on the MPAI-4 ability, adjustment and participation sub-scales (Cohen's d range?=?0.31-1.10). A deterioration in individuals' adjustment was further reported at follow-up, although this was based on limited data. Issues with longer-term rehabilitation service provision were additionally noted. Conclusions: The data support the need for continuity of care, including ongoing emotional support, to cater to the complex and dynamic needs of the ABI population. However, these results need to be considered in the context of a small sample size and quasi-experimental design. PMID:25180709

Curran, Christine; Dorstyn, Diana; Polychronis, Con; Denson, Linley

2015-01-01

367

Oxytocin enhances brain function in children with autism  

PubMed Central

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

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

2013-01-01

368

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

Microsoft Academic Search

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

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

2011-01-01

369

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

370

Cellular localization and functional significance of CYP3A4 in the human epileptic brain  

PubMed Central

Summary Purpose Compelling evidence supports the presence of P450 enzymes (CYPs) in the central nervous system (CNS). However, little information is available on the localization and function of CYPs in the drug-resistant epileptic brain. We have evaluated the pattern of expression of the specific enzyme CYP3A4 and studied its co-localization with MDR1. We also determined whether an association exists between CYP3A4 expression and cell survival. Methods Brain specimens were obtained from eight patients undergoing resection to relieve drug-resistant seizures or to remove a cavernous angioma. Each specimen was partitioned for either immunostaining or primary culture of human endothelial cells and astrocytes. Immunostaining was performed using anti-CYP3A4, MDR1, GFAP, or NeuN antibodies. High performance liquid chromatography–ultraviolet (HPLC-UV) analysis was used to quantify carbamazepine (CBZ) metabolism by these cells. CYP3A4 expression was correlated to DAPI condensation, a marker of cell viability. Human embryonic kidney (HEK) cells were transfected with CYP3A4 to further evaluate the link between CYP3A4 levels, CBZ metabolism, and cell viability. Key Findings CYP3A4 was expressed by blood–brain barrier (BBB) endothelial cells and by the majority of neurons (75 ± 10%). Fluorescent immunostaining showed coexpression of CYP3A4 and MDR1 in endothelial cells and neurons. CYP3A4 expression inversely correlated with DAPI nuclear condensation. CYP3A4 overexpression in HEK cells conferred resistance to cytotoxic levels of carbamazepine. CYP3A4 levels positively correlated with the amount of CBZ metabolized. Significance CYP3A4 brain expression is not only associated with drug metabolism but may also represent a cytoprotective mechanism. Coexpression of CYP3A4 and MDR1 may be involved in cell survival in the diseased brain. PMID:21294720

Ghosh, Chaitali; Marchi, Nicola; Desai, Nirav K.; Puvenna, Vikram; Hossain, Mohammed; Gonzalez-Martinez, Jorge; Alexopoulos, Andreas V.; Janigro, Damir

2011-01-01

371

Changes in functional brain networks following sports-related concussion in adolescents.  

PubMed

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

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

2014-12-01

372

Patient-specific models and simulations of deep brain stimulation for postoperative follow-up  

Microsoft Academic Search

\\u000a Deep brain stimulation (DBS) is an established treatment for Parkinson’s disease (PD). The success of DBS is highly dependent\\u000a on electrode location and electrical parameter settings. In this study patient-specific computer models of DBS were used for\\u000a postoperative follow-up in three PD patients who suffered from stimulation induced hypomania, dysarthria, and uncontrollable\\u000a laughter respectively. The overall aim of the study

Mattias Åström; Elina Tripoliti; Irene Martinez-Torres; Ludvic U. Zrinzo; Patricia Limousin; Marwan I. Hariz; Karin Wårdell

373

Graph analysis of functional brain networks: practical issues in translational neuroscience.  

PubMed

The brain can be regarded as a network: a connected system where nodes, or units, represent different specialized regions and links, or connections, represent communication pathways. From a functional perspective, communication is coded by temporal dependence between the activities of different brain areas. In the last decade, the abstract representation of the brain as a graph has allowed to visualize functional brain networks and describe their non-trivial topological properties in a compact and objective way. Nowadays, the use of graph analysis in translational neuroscience has become essential to quantify brain dysfunctions in terms of aberrant reconfiguration of functional brain networks. Despite its evident impact, graph analysis of functional brain networks is not a simple toolbox that can be blindly applied to brain signals. On the one hand, it requires the know-how of all the methodological steps of the pipeline that manipulate the input brain signals and extract the functional network properties. On the other hand, knowledge of the neural phenomenon under study is required to perform physiologically relevant analysis. The aim of this review is to provide practical indications to make sense of brain network analysis and contrast counterproductive attitudes. PMID:25180301

De Vico Fallani, Fabrizio; Richiardi, Jonas; Chavez, Mario; Achard, Sophie

2014-10-01

374

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

E-print Network

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

Gorodnitsky, Irina

375

Estimation and specification tests of count data recreation demand functions  

E-print Network

ESTIMATION AND SPECIFICATION TESTS OF COUNT DATA RECREATION DEMAND FUNCTIONS A Thesis IRMA ADRIANA GOMEZ Submitted to the Office of Graduate Studies of Texas A8cM University in partial fulfillment of the requirements for the degree of MASTER... OF SCIENCE December 1991 Major Subject: Agricultural Economics ESTIMATION AND SPECIFICATION TESTS OF COUNT DATA RECREATION DEMAND FUNCTIONS A Thesis by IRMA ADRIANA GOMEZ Approved as to style and content by: T o a, Jr. (C a' of Committee) Lonnie...

Gomez, Irma Adriana

1991-01-01

376

Functional Specifications for Typewriter-Like TimeSharing Terminals  

Microsoft Academic Search

A set of detailed functmnal specifications is presented here for typewriter-like terminals (e g. teletypewriters) to be used on-line with time-sharing computer systems The emphasis is on the functions to be provided (rather than on the specifics of the implementation of such functions), as well as on user needs and on human factors relevant to such terminals None of the

Ted A. Dolotta

1970-01-01

377

The discovery of population differences in network community structure: New methods and applications to brain functional networks in schizophrenia  

PubMed Central

The modular organization of the brain network can vary in two fundamental ways. The amount of interversus intra-modular connections between network nodes can be altered, or the community structure itself can be perturbed, in terms of which nodes belong to which modules (or communities). Alterations have previously been reported in modularity, which is a function of the proportion of intra-modular edges over all modules in the network. For example, we have reported that modularity is decreased in functional brain networks in schizophrenia: There are proportionally more inter-modular edges and fewer intra-modular edges. However, despite numerous and increasing studies of brain modular organization, it is not known how to test for differences in the community structure, i.e., the assignment of regional nodes to specific modules. Here, we introduce a method based on the normalized mutual information between pairs of modular networks to show that the community structure of the brain network is significantly altered in schizophrenia, using resting-state fMRI in 19 participants with childhood-onset schizophrenia and 20 healthy participants. We also develop tools to show which specific nodes (or brain regions) have significantly different modular communities between groups, a subset that includes right insular and perisylvian cortical regions. The methods that we propose are broadly applicable to other experimental contexts, both in neuroimaging and other areas of network science. PMID:22119652

Alexander-Bloch, Aaron; Lambiotte, Renaud; Roberts, Ben; Giedd, Jay; Gogtay, Nitin; Bullmore, Ed

2012-01-01

378

Functional brain imaging of cognitive dysfunction in Parkinson's disease.  

PubMed

Multiple factors are involved in the development of cognitive impairment in Parkinson's disease (PD) and related disorders. Notably, several underlying factors, such as monoaminergic dysfunction, Lewy body pathology, Alzheimer disease-like pathology and cerebrovascular disease are implied in the PD pathophysiology of cognitive impairment. The mesocortical dopaminergic system is associated with executive functions which are frequently affected in PD and are influenced by local levodopa concentration, dopamine metabolism and baseline performance status. The ventral striatum and frontal cortex are associated with impulse control disorders reported in PD patients treated with dopamine replacement therapy. Cholinergic impairment in PD plays a cardinal role in the development of dementia. Acetylcholinesterase positron emission tomography demonstrates that posterior brain areas are related to cognitive decline in PD patients. Amyloid radiotracer illustrates that patients with PD with severe cognitive impairment were prone to accompanied cortical amyloid deposition. Metabolism/perfusion change associated with cognitive impairment in PD, so-called PD related cognitive pattern, is characterised by reduced frontoparietal activity and is an effective way to differentiate and monitor cognitive function of individual PD patients. Cognitive impairment in PD cannot be explained by a single mechanism and is entangled by multiple factors. Imaging studies can unravel each pathological domain, further shed light on the interrelation between different pathomechanisms, not only in PD but also in other dementia related disorders, and thereby integrate its interpretation to apply to therapeutics in individual patients. PMID:22807560

Hirano, Shigeki; Shinotoh, Hitoshi; Eidelberg, David

2012-10-01

379

An evaluation of the left-brain vs. right-brain hypothesis with resting state functional connectivity magnetic resonance imaging.  

PubMed

Lateralized brain regions subserve functions such as language and visuospatial processing. It has been conjectured that individuals may be left-brain dominant or right-brain dominant based on personality and cognitive style, but neuroimaging data has not provided clear evidence whether such phenotypic differences in the strength of left-dominant or right-dominant networks exist. We evaluated whether strongly lateralized connections covaried within the same individuals. Data were analyzed from publicly available resting state scans for 1011 individuals between the ages of 7 and 29. For each subject, functional lateralization was measured for each pair of 7266 regions covering the gray matter at 5-mm resolution as a difference in correlation before and after inverting images across the midsagittal plane. The difference in gray matter density between homotopic coordinates was used as a regressor to reduce the effect of structural asymmetries on functional lateralization. Nine left- and 11 right-lateralized hubs were identified as peaks in the degree map from the graph of significantly lateralized connections. The left-lateralized hubs included regions from the default mode network (medial prefrontal cortex, posterior cingulate cortex, and temporoparietal junction) and language regions (e.g., Broca Area and Wernicke Area), whereas the right-lateralized hubs included regions from the attention control network (e.g., lateral intraparietal sulcus, anterior insula, area MT, and frontal eye fields). Left- and right-lateralized hubs formed two separable networks of mutually lateralized regions. Connections involving only left- or only right-lateralized hubs showed positive correlation across subjects, but only for connections sharing a node. Lateralization of brain connections appears to be a local rather than global property of brain networks, and our data are not consistent with a whole-brain phenotype of greater "left-brained" or greater "right-brained" network strength across individuals. Small increases in lateralization with age were seen, but no differences in gender were observed. PMID:23967180

Nielsen, Jared A; Zielinski, Brandon A; Ferguson, Michael A; Lainhart, Janet E; Anderson, Jeffrey S

2013-01-01

380

An Evaluation of the Left-Brain vs. Right-Brain Hypothesis with Resting State Functional Connectivity Magnetic Resonance Imaging  

PubMed Central

Lateralized brain regions subserve functions such as language and visuospatial processing. It has been conjectured that individuals may be left-brain dominant or right-brain dominant based on personality and cognitive style, but neuroimaging data has not provided clear evidence whether such phenotypic differences in the strength of left-dominant or right-dominant networks exist. We evaluated whether strongly lateralized connections covaried within the same individuals. Data were analyzed from publicly available resting state scans for 1011 individuals between the ages of 7 and 29. For each subject, functional lateralization was measured for each pair of 7266 regions covering the gray matter at 5-mm resolution as a difference in correlation before and after inverting images across the midsagittal plane. The difference in gray matter density between homotopic coordinates was used as a regressor to reduce the effect of structural asymmetries on functional lateralization. Nine left- and 11 right-lateralized hubs were identified as peaks in the degree map from the graph of significantly lateralized connections. The left-lateralized hubs included regions from the default mode network (medial prefrontal cortex, posterior cingulate cortex, and temporoparietal junction) and language regions (e.g., Broca Area and Wernicke Area), whereas the right-lateralized hubs included regions from the attention control network (e.g., lateral intraparietal sulcus, anterior insula, area MT, and frontal eye fields). Left- and right-lateralized hubs formed two separable networks of mutually lateralized regions. Connections involving only left- or only right-lateralized hubs showed positive correlation across subjects, but only for connections sharing a node. Lateralization of brain connections appears to be a local rather than global property of brain networks, and our data are not consistent with a whole-brain phenotype of greater “left-brained” or greater “right-brained” network strength across individuals. Small increases in lateralization with age were seen, but no differences in gender were observed. PMID:23967180

Nielsen, Jared A.; Zielinski, Brandon A.; Ferguson, Michael A.; Lainhart, Janet E.; Anderson, Jeffrey S.

2013-01-01

381

GPR124 Functions as a WNT7-Specific Coactivator of Canonical ?-Catenin Signaling.  

PubMed

G protein-coupled receptor 124 (GPR124) is an orphan receptor in the adhesion family of GPCRs, and previous global or endothelial-specific disruption of Gpr124 in mice led to defective CNS angiogenesis and blood-brain barriergenesis. Similar developmental defects were observed following dual deletion of Wnt7a/Wnt7b or deletion of ?-catenin in endothelial cells, suggesting a possible relationship between GPR124 and canonical WNT signaling. Here, we show using in vitro reporter assays, mutation analysis, and genetic interaction studies in vivo that GPR124 functions as a WNT7A/WNT7B-specific costimulator of ?-catenin signaling in brain endothelium. WNT7-stimulated ?-catenin signaling was dependent upon GPR124's intracellular PDZ binding motif and a set of leucine-rich repeats in its extracellular domain. This study reveals a vital role for GPR124 in potentiation of WNT7-induced canonical ?-catenin signaling with important implications for understanding and manipulating CNS-specific angiogenesis and blood-brain barriergenesis. PMID:25558062

Posokhova, Ekaterina; Shukla, Animesh; Seaman, Steven; Volate, Suresh; Hilton, Mary Beth; Wu, Bofan; Morris, Holly; Swing, Deborah A; Zhou, Ming; Zudaire, Enrique; Rubin, Jeffrey S; St Croix, Brad

2015-01-13

382

Functional Brain Network Abnormalities during Verbal Working Memory Performance in Adolescents and Young Adults with Dyslexia  

ERIC Educational Resources Information Center

Behavioral and functional neuroimaging studies indicate deficits in verbal working memory (WM) and frontoparietal dysfunction in individuals with dyslexia. Additionally, structural brain abnormalities in dyslexics suggest a dysconnectivity of brain regions associated with phonological processing. However, little is known about the functional

Wolf, Robert Christian; Sambataro, Fabio; Lohr, Christina; Steinbrink, Claudia; Martin, Claudia; Vasic, Nenad

2010-01-01

383

Spontaneous Pain and Brain Activity in Neuropathic Pain: Functional MRI and  

E-print Network

Spontaneous Pain and Brain Activity in Neuropathic Pain: Functional MRI and Pharmacologic of Physiology, Chicago, IL 60611, USA. E-mail: a-apkarian@northwestern.edu Current Pain and Headache Reports LLC Functional brain imaging studies in chronic neuropathic pain patients have lagged far behind

Apkarian, A. Vania

384

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

E-print Network

Experience induces functional reorganization in brain regions involved in odor imagery in perfumers@olfac.univ-lyon1.fr Short Title Functional plasticity in perfumers Number of figures / tables: 5 / 1 inserm the brain's ability to adapt to environmental change. Perfumers are a small population who claim to have

Paris-Sud XI, Université de

385

Voluntary exercise may engage proteasome function to benefit the brain after trauma  

Microsoft Academic Search

Brain trauma is associated with long-term decrements in synaptic plasticity and cognitive function, which likely reside on the acute effects of the injury on protein structure and function. Based on the action of proteasome on protein synthesis and degradation we have examined the effects of brain injury on proteasome level\\/activity and the potential of exercise to interact with the effects

Zsofia Szabo; Zhe Ying; Zsolt Radak; Fernando Gomez-Pinilla

2010-01-01

386

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

E-print Network

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

Feng, Jianfeng

387

Regions, systems, and the brain: Hierarchical measures of functional integration in fMRI  

Microsoft Academic Search

In neuroscience, the notion has emerged that the brain abides by two principles: segregation and integration. Segregation into functionally specialized systems and integration of information flow across systems are basic principles that are thought to shape the functional architecture of the brain. A measure called integration, originating from information theory and derived from mutual information, has been proposed to characterize

Guillaume Marrelec; Pierre Bellec; Alexandre Krainik; Hugues Duffau; Mélanie Pélégrini-Issac; Stéphane Lehericy; Habib Benali; Julien Doyon

2008-01-01

388

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

389

HSP101 functions as a specific translational regulatory protein whose  

E-print Network

; protein synthesis; RNA-binding protein] Received June 17, 1998; revised version accepted August 21, 1998HSP101 functions as a specific translational regulatory protein whose activity is regulated viral RNA functions as a translational enhancer. Sequence analysis of a 102-kD protein, identified

Tullos, Desiree

390

BrainCAT - a tool for automated and combined functional magnetic resonance imaging and diffusion tensor imaging brain connectivity analysis  

PubMed Central

Multimodal neuroimaging studies have recently become a trend in the neuroimaging field and are certainly a standard for the future. Brain connectivity studies combining functional activation patterns using resting-state or task-related functional magnetic resonance imaging (fMRI) and diffusion tensor imaging (DTI) tractography have growing popularity. However, there is a scarcity of solutions to perform optimized, intuitive, and consistent multimodal fMRI/DTI studies. Here we propose a new tool, brain connectivity analysis tool (BrainCAT), for an automated and standard multimodal analysis of combined fMRI/DTI data, using freely available tools. With a friendly graphical user interface, BrainCAT aims to make data processing easier and faster, implementing a fully automated data processing pipeline and minimizing the need for user intervention, which hopefully will expand the use of combined fMRI/DTI studies. Its validity was tested in an aging study of the default mode network (DMN) white matter connectivity. The results evidenced the cingulum bundle as the structural connector of the precuneus/posterior cingulate cortex and the medial frontal cortex, regions of the DMN. Moreover, mean fractional anisotropy (FA) values along the cingulum extracted with BrainCAT showed a strong correlation with FA values from the manual selection of the same bundle. Taken together, these results provide evidence that BrainCAT is suitable for these analyses. PMID:24319419

Marques, Paulo; Soares, José M.; Alves, Victor; Sousa, Nuno

2013-01-01

391

Functional connectivity in BOLD and CBF data: Similarity and reliability of resting brain networks.  

PubMed

Resting-state functional connectivity (FC) fMRI (rs-fcMRI) offers an appealing approach to mapping the brain's intrinsic functional organization. Blood oxygen level dependent (BOLD) and arterial spin labeling (ASL) are the two main rs-fcMRI approaches to assess alterations in brain networks associated with individual differences, behavior and psychopathology. While the BOLD signal is stronger with a higher temporal resolution, ASL provides quantitative, direct measures of the physiology and metabolism of specific networks. This study systematically investigated the similarity and reliability of resting brain networks (RBNs) in BOLD and ASL. A 2×2×2 factorial design was employed where each subject underwent repeated BOLD and ASL rs-fcMRI scans on two occasions on two MRI scanners respectively. Both independent and joint FC analyses revealed common RBNs in ASL and BOLD rs-fcMRI with a moderate to high level of spatial overlap, verified by Dice Similarity Coefficients. Test-retest analyses indicated more reliable spatial network patterns in BOLD (average modal Intraclass Correlation Coefficients: 0.905±0.033 between-sessions; 0.885±0.052 between-scanners) than ASL (0.545±0.048; 0.575±0.059). Nevertheless, ASL provided highly reproducible (0.955±0.021; 0.970±0.011) network-specific CBF measurements. Moreover, we observed positive correlations between regional CBF and FC in core areas of all RBNs indicating a relationship between network connectivity and its baseline metabolism. Taken together, the combination of ASL and BOLD rs-fcMRI provides a powerful tool for characterizing the spatiotemporal and quantitative properties of RBNs. These findings pave the way for future BOLD and ASL rs-fcMRI studies in clinical populations that are carried out across time and scanners. PMID:25463468

Jann, Kay; Gee, Dylan G; Kilroy, Emily; Schwab, Simon; Smith, Robert X; Cannon, Tyrone D; Wang, Danny J J

2015-02-01

392

Deep brain optical measurements of cell type–specific neural activity in behaving mice  

PubMed Central

Recent advances in genetically encoded fluorescent sensors enable the monitoring of cellular events from genetically defined groups of neurons in vivo. In this protocol, we describe how to use a time-correlated single-photon counting (tcspc)–based fiber optics system to measure the intensity, emission spectra and lifetime of fluorescent biosensors expressed in deep brain structures in freely moving mice. When combined with cre-dependent selective expression of genetically encoded ca2+ indicators (GecIs), this system can be used to measure the average neural activity from a specific population of cells in mice performing complex behavioral tasks. as an example, we used viral expression of GcaMps in striatal projection neurons (spns) and recorded the fluorescence changes associated with calcium spikes from mice performing a lever-pressing operant task. the whole procedure, consisting of virus injection, behavior training and optical recording, takes 3–4 weeks to complete. With minor adaptations, this protocol can also be applied to recording cellular events from other cell types in deep brain regions, such as dopaminergic neurons in the ventral tegmental area. the simultaneously recorded fluorescence signals and behavior events can be used to explore the relationship between the neural activity of specific brain circuits and behavior. PMID:24784819

Cui, Guohong; Jun, Sang Beom; Jin, Xin; Luo, Guoxiang; Pham, Michael D; Lovinger, David M; Vogel, Steven S; Costa, Rui M

2014-01-01

393

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

PubMed

We present a numerical study of an array-based microwave beamforming approach for non-invasive hyperthermia treatment of pediatric brain tumors. The transmit beamformer is designed to achieve localized heating-that is, to achieve constructive interference and selective absorption of the transmitted electromagnetic waves at the desired focus location in the brain while achieving destructive interference elsewhere. The design process takes into account patient-specific and target-specific propagation characteristics at 1 GHz. We evaluate the effectiveness of the beamforming approach using finite-difference time-domain simulations of two MRI-derived child head models from the Virtual Family (IT'IS Foundation). Microwave power deposition and the resulting steady-state thermal distribution are calculated for each of several randomly chosen focus locations. We also explore the robustness of the design to mismatch between the assumed and actual dielectric properties of the patient. Lastly, we demonstrate the ability of the beamformer to suppress hot spots caused by pockets of cerebrospinal fluid (CSF) in the brain. Our results show that microwave beamforming has the potential to create localized heating zones in the head models for focus locations that are not surrounded by large amounts of CSF. These promising results suggest that the technique warrants further investigation and development. PMID:21464536

Burfeindt, Matthew J; Zastrow, Earl; Hagness, Susan C; Van Veen, Barry D; Medow, Joshua E

2011-05-01

394

Combining specificity determining and conserved residues improves functional site prediction  

Microsoft Academic Search

BACKGROUND: Predicting the location of functionally important sites from protein sequence and\\/or structure is a long-standing problem in computational biology. Most current approaches make use of sequence conservation, assuming that amino acid residues conserved within a protein family are most likely to be functionally important. Most often these approaches do not consider many residues that act to define specific sub-functions

Olga V. Kalinina; Mikhail S. Gelfand; Robert B. Russell

2009-01-01

395

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

PubMed Central

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

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

2010-01-01

396

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

PubMed

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

Vizi, E S; Fekete, A; Karoly, R; Mike, A

2010-06-01

397

Cardiovascular risks and brain function: a functional magnetic resonance imaging study of executive function in older adults  

PubMed Central

Cardiovascular (CV) risk factors, such as hypertension, diabetes, and hyperlipidemia are associated with cognitive impairment and risk of dementia in older adults. However, the mechanisms linking them are not clear. This study aims to investigate the association between aggregate CV risk, assessed by the Framingham general cardiovascular risk profile, and functional brain activation in a group of community-dwelling older adults. Sixty participants (mean age: 64.6 years) from the Brain Health Study, a nested study of the Baltimore Experience Corps Trial, underwent functional magnetic resonance imaging using the Flanker task. We found that participants with higher CV risk had greater task-related activation in the left inferior parietal region, and this increased activation was associated with poorer task performance. Our results provide insights into the neural systems underlying the relationship between CV risk and executive function. Increased activation of the inferior parietal region may offer a pathway through which CV risk increases risk for cognitive impairment. PMID:24439485

Chuang, Yi-Fang; Eldreth, Dana; Erickson, Kirk I.; Varma, Vijay; Harris, Gregory; Fried, Linda P.; Rebok, George W.; Tanner, Elizabeth K.; Carlson, Michelle C.

2014-01-01

398

Multiple Functions of Endocannabinoid Signaling in the Brain  

PubMed Central

Despite being regarded as a hippie science for decades, cannabinoid research has finally found its well-deserved position in mainstream neuroscience. A series of groundbreaking discoveries revealed that endocannabinoid molecules are as widespread and important as conventional neurotransmitters like glutamate or GABA, yet act in profoundly unconventional ways. We aim to illustrate how uncovering the molecular, anatomical and physiological characteristics of endocannabinoid signaling revealed new mechanistic insights into several fundamental phenomena in synaptic physiology. First, we summarize unexpected advances in the molecular complexity of biogenesis and inactivation of the two endocannabinoids, anandamide and 2-arachidonoylglycerol. Then we show how these new metabolic routes are integrated into well-known intracellular signaling pathways. These endocannabinoid-producing signalosomes operate in phasic and tonic modes thereby differentially governing homeostatic, short-term and long-term synaptic plasticity throughout the brain. Finally, we discuss how cell type- and synapse-specific refinement of endocannabinoid signaling may explain the characteristic behavioral effects of cannabinoids. PMID:22524785

Katona, István; Freund, Tamás F.

2014-01-01

399

Working memory in attention deficit/hyperactivity disorder is characterized by a lack of specialization of brain function.  

PubMed

Working memory impairments are frequent in Attention Deficit/Hyperactivity Disorder (ADHD) and create problems along numerous functional dimensions. The present study utilized the Visual Serial Addition Task (VSAT) and functional magnetic resonance imaging (fMRI) to explore working memory processes in thirteen typically developing (TD) control and thirteen children with ADHD, Combined type. Analysis of Variance (ANOVA) was used to examine both main effects and interactions. Working memory-specific activity was found in TD children in the bilateral prefrontal cortex. In contrast the within-group map in ADHD did not reveal any working-memory specific regions. Main effects of condition suggested that the right middle frontal gyrus (BA6) and the right precuneus were engaged by both groups during working memory processing. Group differences were driven by significantly greater, non-working memory-specific, activation in the ADHD relative to TD group in the bilateral insula extending into basal ganglia and the medial prefrontal cortex. A region of interest analysis revealed a region in left middle frontal gyrus that was more active during working memory in TD controls. Thus, only the TD group appeared to display working memory-modulated brain activation. In conclusion, children with ADHD demonstrated reduced working memory task specific brain activation in comparison to their peers. These data suggest inefficiency in functional recruitment by individuals with ADHD represented by a poor match between task demands and appropriate levels of brain activity. PMID:22102882

Fassbender, Catherine; Schweitzer, Julie B; Cortes, Carlos R; Tagamets, Malle A; Windsor, T Andrew; Reeves, Gloria M; Gullapalli, Rao

2011-01-01

400

Working Memory in Attention Deficit/Hyperactivity Disorder is Characterized by a Lack of Specialization of Brain Function  

PubMed Central

Working memory impairments are frequent in Attention Deficit/Hyperactivity Disorder (ADHD) and create problems along numerous functional dimensions. The present study utilized the Visual Serial Addition Task (VSAT) and functional magnetic resonance imaging (fMRI) to explore working memory processes in thirteen typically developing (TD) control and thirteen children with ADHD, Combined type. Analysis of Variance (ANOVA) was used to examine both main effects and interactions. Working memory-specific activity was found in TD children in the bilateral prefrontal cortex. In contrast the within-group map in ADHD did not reveal any working-memory specific regions. Main effects of condition suggested that the right middle frontal gyrus (BA6) and the right precuneus were engaged by both groups during working memory processing. Group differences were driven by significantly greater, non-working memory-specific, activation in the ADHD relative to TD group in the bilateral insula extending into basal ganglia and the medial prefrontal cortex. A region of interest analysis revealed a region in left middle frontal gyrus that was more active during working memory in TD controls. Thus, only the TD group appeared to display working memory-modulated brain activation. In conclusion, children with ADHD demonstrated reduced working memory task specific brain activation in comparison to their peers. These data suggest inefficiency in functional recruitment by individuals with ADHD represented by a poor match between task demands and appropriate levels of brain activity. PMID:22102882

Cortes, Carlos R.; Tagamets, Malle A.; Windsor, T. Andrew; Reeves, Gloria M.; Gullapalli, Rao

2011-01-01

401

Minimizing the non-specific binding of nanoparticles to the brain enables active targeting of Fn14-positive glioblastoma cells.  

PubMed

A major limitation in the treatment of glioblastoma (GBM), the most common and deadly primary brain cancer, is delivery of therapeutics to invading tumor cells outside of the area that is safe for surgical removal. A promising way to target invading GBM cells is via drug-loaded nanoparticles that bind to fibroblast growth factor-inducible 14 (Fn14), thereby potentially improving efficacy and reducing toxicity. However, achieving broad particle distribution and nanoparticle targeting within the brain remains a significant challenge due to the adhesive extracellular matrix (ECM) and clearance mechanisms in the brain. In this work, we developed Fn14 monoclonal antibody-decorated nanoparticles that can efficiently penetrate brain tissue. We show these Fn14-targeted brain tissue penetrating nanoparticles are able to (i) selectively bind to recombinant Fn14 but not brain ECM proteins, (ii) associate with and be internalized by Fn14-positive GBM cells, and (iii) diffuse within brain tissue in a manner similar to non-targeted brain penetrating nanoparticles. In addition, when administered intracranially, Fn14-targeted nanoparticles showed improved tumor cell co-localization in mice bearing human GBM xenografts compared to non-targeted nanoparticles. Minimizing non-specific binding of targeted nanoparticles in the brain may greatly improve the access of particulate delivery systems to remote brain tumor cells and other brain targets. PMID:25542792

Schneider, Craig S; Perez, Jimena G; Cheng, Emily; Zhang, Clark; Mastorakos, Panagiotis; Hanes, Justin; Winkles, Jeffrey A; Woodworth, Graeme F; Kim, Anthony J

2015-02-01

402

Brain motor system function in a patient with complete spinal cord injury following extensive brain–computer interface training  

Microsoft Academic Search

Although several features of brain motor function appear to be preserved even in chronic complete SCI, previous functional\\u000a MRI (fMRI) studies have also identified significant derangements such as a strongly reduced volume of activation, a poor modulation\\u000a of function and abnormal activation patterns. It might be speculated that extensive motor imagery training may serve to prevent\\u000a such abnormalities. We here

Christian Enzinger; Stefan Ropele; Franz Fazekas; Marisa Loitfelder; Faton Gorani; Thomas Seifert; Gudrun Reiter; Christa Neuper; Gert Pfurtscheller; Gernot Müller-Putz

2008-01-01

403

The Developmental Trajectory of Brain-Scalp Distance from Birth through Childhood: Implications for Functional Neuroimaging  

PubMed Central

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

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

2011-01-01

404

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

PubMed Central

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

Holschneider, DP; Maarek, J-M I

2008-01-01

405

High-resolution photoacoustic tomography of resting-state functional connectivity in the mouse brain  

PubMed Central

The increasing use of mouse models for human brain disease studies presents an emerging need for a new functional imaging modality. Using optical excitation and acoustic detection, we developed a functional connectivity photoacoustic tomography system, which allows noninvasive imaging of resting-state functional connectivity in the mouse brain, with a large field of view and a high spatial resolution. Bilateral correlations were observed in eight functional regions, including the olfactory bulb, limbic, parietal, somatosensory, retrosplenial, visual, motor, and temporal regions, as well as in several subregions. The borders and locations of these regions agreed well with the Paxinos mouse brain atlas. By subjecting the mouse to alternating hyperoxic and hypoxic conditions, strong and weak