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1

Mechanisms of brain plasticity: From normal brain function to pathology  

Microsoft Academic Search

Since this list of mechanisms covers much of what we know about how brain cells operate, one might object to using such a broad brush in characterizing a purportedly special feature of brain function-“plas ticity.” But that is really just the point. If a significant aspect of brain function is “plasticity,” as I believe to be the case, then all

Philip A. Schwartzkroin

2001-01-01

2

Functional Plasticity or Vulnerability After Early Brain Injury?  

Microsoft Academic Search

ABSTRACT. Context. Traumatic brain injury (TBI) is a common, acquired, childhood disability that may be used as a model to understand more completely the im- pact of early brain injury on both brain structure and day-to-day function. Contrary to previously held views of the “plasticity” of the young brain, recent research suggests that such early insults may have a profound

Vicki Anderson; Cathy Catroppa; Sue Morse; Flora Haritou; Jeffrey Rosenfeld

2010-01-01

3

Early brain injury and plasticity: Reorganization and functional Recovery  

Microsoft Academic Search

One of the most remarkable observations in developmental neuroscience is the plasticity of the developing brain. Although\\u000a recent findings suggest that the developing brain possesses substantial compensatory potential, the mechanisms of reorganization\\u000a and its limitations remain largely unknown. This review includes studies elucidating the complexities of brain reorganization\\u000a in response to early brain injury. It describes the factors influencing the

Ana Katuši?

2011-01-01

4

Brain plasticity and tumors  

Microsoft Academic Search

Brain plasticity is the potential of the nervous system to reshape itself during ontogeny, learning or following injuries.\\u000a The first part of this article reviews the pathophysiological mechanisms underlying plasticity at different functional levels.\\u000a Such plastic potential means that the anatomo-functional organization of the brain in humans, both physiological and pathological,\\u000a has flexibility. Patterns of reorganization may differ according to

H. Duffau; Gui de Chauliac; CHU de Montpellier; CNRS FRE; Boulogne Billancourt

5

Narrative Skill in Children with Early Unilateral Brain Injury: A Possible Limit to Functional Plasticity  

ERIC Educational Resources Information Center

Children with pre- or perinatal brain injury (PL) exhibit marked plasticity for language learning. Previous work has focused mostly on the emergence of earlier-developing skills, such as vocabulary and syntax. Here we ask whether this plasticity for earlier-developing aspects of language extends to more complex, later-developing language functions

Demir, Ozlem Ece; Levine, Susan C.; Goldin-Meadow, Susan

2010-01-01

6

Music drives brain plasticity  

PubMed Central

Music is becoming more and more of an issue in the cognitive neurosciences. A major finding in this research area is that musical practice is associated with structural and functional plasticity of the brain. In this brief review, I will give an overview of the most recent findings of this research area.

2009-01-01

7

Brain plasticity and functionality explored by nonlinear optical microscopy  

NASA Astrophysics Data System (ADS)

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

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

2010-02-01

8

Music and brain plasticity  

Microsoft Academic Search

Complex and widespread activation in many brain areas is seen while performing, listening or mentally imaging music, activity that varies with training, previous exposure, personal preference, emotional involvement and many other factors. Playing a musical instrument demands extensive motor and cognitive abilities, and early musical learning results in plastic reorganization of the developing brain one example being the increased cortical

BARBRO B. JOHANSSON

2006-01-01

9

Narrative Skill in Children with Early Unilateral Brain Injury: A Possible Limit to Functional Plasticity  

PubMed Central

Children with pre- or perinatal brain injury (PL) exhibit marked plasticity for language learning. Previous work mostly focused on the emergence of earlier developing skills, such as vocabulary and syntax. Here we ask whether this plasticity for earlier developing aspects of language extends to more complex, later-developing language functions by examining the narrative production of children with PL. Using an elicitation technique that involves asking children to create stories de novo in response to a story stem, we collected narratives from 11 children with PL and 20 typically-developing (TD) children. Narratives were analyzed for length, diversity of the vocabulary used, use of complex syntax, complexity of the macro-level narrative structure and use of narrative evaluation. Children’s language performance on vocabulary and syntax tasks outside of the narrative context was also measured. Findings show that children with PL produced shorter stories, used less diverse vocabulary, produced structurally less complex stories at the macro-level, and made fewer inferences regarding the cognitive states of the story characters. These differences in the narrative task emerged even though children with PL did not differ from TD children on vocabulary and syntax tasks outside of the narrative context. Thus, findings suggest that there may be limitations to the plasticity for language functions displayed by children with PL, and that these limitations may be most apparent in complex, decontextualized language tasks such as narrative production.

Demir, Ozlem Ece; Levine, Susan C.; Goldin-Meadow, Susan

2009-01-01

10

Narrative Skill in Children with Early Unilateral Brain Injury: A Possible Limit to Functional Plasticity  

ERIC Educational Resources Information Center

|Children with pre- or perinatal brain injury (PL) exhibit marked plasticity for language learning. Previous work has focused mostly on the emergence of earlier-developing skills, such as vocabulary and syntax. Here we ask whether this plasticity for earlier-developing aspects of language extends to more complex, later-developing language…

Demir, Ozlem Ece; Levine, Susan C.; Goldin-Meadow, Susan

2010-01-01

11

Glucocorticoid regulation of brain-derived neurotrophic factor: relevance to hippocampal structural and functional plasticity.  

PubMed

Glucocorticoids serve as key stress response hormones that facilitate stress coping. However, sustained glucocorticoid exposure is associated with adverse consequences on the brain, in particular within the hippocampus. Chronic glucocorticoid exposure evokes neuronal cell damage and dendritic atrophy, reduces hippocampal neurogenesis and impairs synaptic plasticity. Glucocorticoids also alter expression and signaling of the neurotrophin, brain-derived neurotrophic factor (BDNF). Since BDNF is known to promote neuroplasticity, enhance cell survival, increase hippocampal neurogenesis and cellular excitability, it has been hypothesized that specific adverse effects of glucocorticoids may be mediated by attenuating BDNF expression and signaling. The purpose of this review is to summarize the current state of literature examining the influence of glucocorticoids on BDNF, and to address whether specific effects of glucocorticoids arise through perturbation of BDNF signaling. We integrate evidence of glucocorticoid regulation of BDNF at multiple levels, spanning from the well-documented glucocorticoid-induced changes in BDNF mRNA to studies examining alterations in BDNF receptor-mediated signaling. Further, we delineate potential lines of future investigation to address hitherto unexplored aspects of the influence of glucocorticoids on BDNF. Finally, we discuss the current understanding of the contribution of BDNF to the modulation of structural and functional plasticity by glucocorticoids, in particular in the context of the hippocampus. Understanding the mechanistic crosstalk between glucocorticoids and BDNF holds promise for the identification of potential therapeutic targets for disorders associated with the dysfunction of stress hormone pathways. PMID:22967840

Suri, D; Vaidya, V A

2012-09-09

12

Plasticity in the Developing Brain: Intellectual, Language and Academic Functions in Children with Ischaemic Perinatal Stroke  

ERIC Educational Resources Information Center

|The developing brain has the capacity for a great deal of plasticity. A number of investigators have demonstrated that intellectual and language skills may be in the normal range in children following unilateral perinatal stroke. Questions have been raised, however, about whether these skills can be maintained at the same level as the brain

Ballantyne, Angela O.; Spilkin, Amy M.; Hesselink, John; Trauner, Doris A.

2008-01-01

13

Plasticity in the developing brain: intellectual, language and academic functions in children with ischaemic perinatal stroke  

Microsoft Academic Search

The developing brain has the capacity for a great deal of plasticity. A number of investigators have demon- strated that intellectual and language skills may be in the normal range in children following unilateral perinatal stroke. Questions have been raised, however, about whether these skills can be maintained at the same level as the brain matures. This study aimed to

Angela O. Ballantyne; Amy M. Spilkin; John Hesselink; Doris A. Trauner

2008-01-01

14

Psychotherapy and brain plasticity  

PubMed Central

In this paper, I will review why psychotherapy is relevant to the question of how consciousness relates to brain plasticity. A great deal of the research and theorizing on consciousness and the brain, including my own on hallucinations for example (Collerton and Perry, 2011) has focused upon specific changes in conscious content which can be related to temporal changes in restricted brain systems. I will argue that psychotherapy, in contrast, allows only a focus on holistic aspects of consciousness; an emphasis which may usefully complement what can be learnt from more specific methodologies.

Collerton, Daniel

2013-01-01

15

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

Microsoft Academic Search

OBJECTIVETo support the hypothesis about the potential compensatory role of ipsilateral corticofugal pathways when the contralateral pathways are impaired by brain tumours.METHODSRetrospective 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

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

2000-01-01

16

Clinical disorders of brain plasticity  

Microsoft Academic Search

Clinical disorders of brain plasticity are common in the practice of child neurology. Children have an enhanced capacity for brain plasticity compared to adults as demonstrated by their superior ability to learn a second language or their capacity to recover from brain injuries or radical surgery such as hemispherectomy for epilepsy. Basic mechanisms that support plasticity during development include persistence

Michael V. Johnston

2004-01-01

17

Structural and functional plasticity of the human brain in posttraumatic stress disorder  

PubMed Central

Posttraumatic stress disorder (PTSD) is associated with long-term changes in neurobiology. Brain areas involved in the stress response include the medial prefrontal cortex, hippocampus, and amygdala. Neurohormonal systems that act on the brain areas to modulate PTSD symptoms and memory include glucocorticoids and norepinephrine. Dysfunction of these brain areas is responsible for the symptoms of PTSD. Brain imaging studies show that PTSD patients have increased amygdala reactivity during fear acquisition. Other studies show smaller hippocampal volume. A failure of medial prefrontal/anterior cingulate activation with re-experiencing of the trauma is hypothesized to represent a neural correlate of the failure of extinction seen in PTSD. The brain has the capacity for plasticity in the aftermath of traumatic stress. Antidepressant treatments and changes in environment can reverse the effects of stress on hippocampal neurogenesis, and humans with PTSD showed increased hippocampal volume with both paroxetine and phenytoin.

Bremner, J. Douglas; Elzinga, Bernet; Schmahl, Christian; Vermetten, Eric

2011-01-01

18

Can noninvasive brain stimulation measure and modulate developmental plasticity to improve function in stroke-induced cerebral palsy?  

PubMed

The permanent nature of motor deficits is a consistent cornerstone of cerebral palsy definitions. Such pessimism is disheartening to children, families, and researchers alike and may no longer be appropriate for it ignores the fantastic plastic potential of the developing brain. Perinatal stroke is presented as the ideal human model of developmental neuroplasticity following distinct, well-defined, focal perinatal brain injury. Elegant animal models are merging with human applied technology methods, including noninvasive brain stimulation for increasingly sophisticated models of plastic motor development following perinatal stroke. In this article, how potential central therapeutic targets are identified and potentially modulated to enhance motor function within these models is discussed. Also, future directions and emerging clinical trials are reviewed. PMID:23948686

Kirton, Adam

2013-06-01

19

Brain plasticity in paediatric neurology  

Microsoft Academic Search

Plasticity includes the brain's capacity to be shaped or moulded by experience, the capacity to learn and remember, and the ability to reorganize and recover after injury. Mechanisms for plasticity include activity-dependent refinement of neuronal connections and synaptic plasticity as a substrate for learning and memory. The molecular mechanisms for these processes utilize signalling cascades that relay messages from synaptic

Michael V Johnston

2003-01-01

20

Development of plasticity of brain function with repeated trainings and passage of time after basal forebrain lesions in rats  

Microsoft Academic Search

Summary Basal forebrain (BF) lesion-induced amnesia in rats is widely used as an animal model of Alzheimer's disease (AD). To study the plasticity of brain function in BF-lesioned rats, we examined the effects of repeated trainings and the passage of time after the lesion on learning ability 3 weeks and 3 months after BF-lesions with ibotenic acid, using an eight-arm

A. Nitta; K. Hayashi; T. Hasegawa; T. Nabeshima

1993-01-01

21

Neural Prostheses and Brain Plasticity  

PubMed Central

The success of modern neural prostheses is dependent on a complex interplay between the devices’ hardware and software and the dynamic environment in which the devices operate: the patient’s body or ‘wetware’. Over 110,000 severe/profoundly deaf individuals presently receive information enabling auditory awareness and speech perception from cochlear implants. The cochlear implant therefore provides a useful case study for a review of the complex interactions between hardware, software and wetware, and of the important role of the dynamic nature of wetware. This review will examine the evidence of changes in the wetware contributing to changes in speech perception and discuss how these changes relate to electrophysiological and functional imaging studies in humans. The relationship between the human data and evidence from animals of the remarkable capacity for plastic change of the central auditory system, even into adulthood, will then be examined. Finally, we will discuss the role of brain plasticity in neural prostheses in general.

Fallon, James B.; Irvine, Dexter R. F.; Shepherd, Robert K.

2010-01-01

22

Brain plasticity and functional losses in the aged: scientific bases for a novel intervention  

Microsoft Academic Search

Aging is associated with progressive losses in function across multiple systems, including sensation, cognition, memory, motor control, and affect. The traditional view has been that functional decline in aging is unavoidable because it is a direct consequence of brain machinery wearing down over time. In recent years, an alternative perspective has emerged, which elaborates on this traditional view of age-related

Henry W. Mahncke; Amy Bronstone; Michael M. Merzenich

2006-01-01

23

Neurogenesis and hippocampal plasticity in adult brain.  

PubMed

Plasticity in the adult brain enables lifelong learning. The fundamental mechanism of adult neural plasticity is activity-dependent reorganization of pre-existing structure, in contrast to the widespread cellular proliferation and migration that occurs during development. Whereas adult hippocampal dentate gyrus continuously generates cohorts of neurons, and newborn neurons integrate into the existing neural circuit under the regulation of existing global and local neural activity, demonstrating a unique cellular and synaptic flexibility in adult brain. Exhibiting an enhanced structural and synaptic plasticity during the maturation, adult-born hippocampal neurons may represent a unique population for hippocampal function. Current evidence indicates that lifelong addition of new hippocampal neurons may extend early developmental plasticity to adulthood, which continuously rejuvenates adult brain. We reviewed most recent advancements in exploring the circuit and behavioral role of adult-born hippocampal neurons. PMID:22879073

Gu, Yan; Janoschka, Stephen; Ge, Shaoyu

2013-01-01

24

Brain plasticity and ion channels  

Microsoft Academic Search

It is generally believed that spatio-temporal configurations of distributed activity in the brain contribute to the coding of neuronal information and that synaptic contacts between nerve cells could play a central role in the formation of privileged pathways of activity. Synaptic plasticity is not the only mode of regulation of information processing in the brain and persistent regulations of ionic

Dominique Debanne; Gaël Daoudal; Valérie Sourdet; Michaël Russier

2003-01-01

25

10 Exercising Your Brain: Training-Related Brain Plasticity  

Microsoft Academic Search

Learning and brain plasticity are fundamental properties of the nervous system, and they hold considerable promise when it comes to learning a second language faster, maintaining our perceptual and cognitive skills as we age, or recovering lost functions after brain injury. Learning is critically dependent on experience and the environment that the learner has to face. A central question then

DAPHNE BAVELIER; C. S. GREEN; M. W. G. DYE

26

Neural plasticity in the ageing brain  

Microsoft Academic Search

The mechanisms involved in plasticity in the nervous system are thought to support cognition, and some of these processes are affected during normal ageing. Notably, cognitive functions that rely on the medial temporal lobe and prefrontal cortex, such as learning, memory and executive function, show considerable age-related decline. It is therefore not surprising that several neural mechanisms in these brain

Sara N. Burke; Carol A. Barnes

2006-01-01

27

The role of Ca²?-stimulated adenylyl cyclases in bidirectional synaptic plasticity and brain function.  

PubMed

The activity-dependent neuronal modification is important for many aspects of adaptive behavior and brain development. Very often, neurological disorders are associated with the alteration of neural signaling pathways that are required for activity-triggered cellular events. Mounting evidence has implicated the role of cyclic AMP (cAMP)-cAMP-dependent protein kinase (PKA)-ERK1/2-cAMP-responsive element-binding protein (CREB) cascade in numerous brain functions such as learning and memory. Ca2+-stimulated type 1 and type 8 adenylyl cyclases (AC1 and AC8) are unique enzymes that couple activity-dependent calcium influx to the activation of cAMP signaling. Here, we summarize some direct evidence to support that Ca2+-stimulated cAMP signaling regulates molecular and cellular substrates of neuronal adaptation. Specifically, the function of AC1 and AC8 in synaptic functions, such as long-term potentiation, long-term depression, and depotentiation, has been examined by using genetic deletion and overexpression approaches. Consistent with the current hypothesis, the Ca2+-stimulated cAMP production through AC1 and AC8 is required for the activity-dependent activation of the ERK1/2-CREB cascade. We further describe the phenotypes of AC1/AC8 mutant mice in memory formation and other adaptive brain functions. The findings may suggest Ca2+-stimulated AC as therapeutic target for the treatment of mental retardation, pain, addiction, anxiety, depression, and neurodegeneration. PMID:22718613

Wang, Hongbing; Zhang, Ming

2012-01-01

28

Neural prostheses and brain plasticity  

NASA Astrophysics Data System (ADS)

The success of modern neural prostheses is dependent on a complex interplay between the devices' hardware and software and the dynamic environment in which the devices operate: the patient's body or 'wetware'. Over 120 000 severe/profoundly deaf individuals presently receive information enabling auditory awareness and speech perception from cochlear implants. The cochlear implant therefore provides a useful case study for a review of the complex interactions between hardware, software and wetware, and of the important role of the dynamic nature of wetware. In the case of neural prostheses, the most critical component of that wetware is the central nervous system. This paper will examine the evidence of changes in the central auditory system that contribute to changes in performance with a cochlear implant, and discuss how these changes relate to electrophysiological and functional imaging studies in humans. The relationship between the human data and evidence from animals of the remarkable capacity for plastic change of the central auditory system, even into adulthood, will then be examined. Finally, we will discuss the role of brain plasticity in neural prostheses in general.

Fallon, James B.; Irvine, Dexter R. F.; Shepherd, Robert K.

2009-12-01

29

Structural and functional plasticity of the human brain in posttraumatic stress disorder  

Microsoft Academic Search

Posttraumatic stress disorder (PTSD) is associated with long-term changes in neurobiology. Brain areas involved in the stress response include the medial prefrontal cortex, hippocampus, and amygdala. Neurohormonal systems that act on the brain areas to modulate PTSD symptoms and memory include glucocorticoids and norepinephrine. Dysfunction of these brain areas is responsible for the symptoms of PTSD. Brain imaging studies show

J. Douglas Bremner; Bernet Elzinga; Christian Schmahl; Eric Vermetten

2007-01-01

30

Ben's Plastic Brain  

ERIC Educational Resources Information Center

This article shares a story of Ben who as a result of his premature birth, suffered a brain hemorrhage resulting in cerebral palsy, which affected his left side (left hemiparesis) and caused learning disabilities. Despite these challenges, he graduated from college and currently works doing information management for a local biotech start-up…

Kaplan, Susan L.

2010-01-01

31

Ben's Plastic Brain  

ERIC Educational Resources Information Center

|This article shares a story of Ben who as a result of his premature birth, suffered a brain hemorrhage resulting in cerebral palsy, which affected his left side (left hemiparesis) and caused learning disabilities. Despite these challenges, he graduated from college and currently works doing information management for a local biotech start-up…

Kaplan, Susan L.

2010-01-01

32

Stem cells in brain plasticity and repair  

Microsoft Academic Search

Findings over the past decade demonstrating persistent neurogenesis in the adult brain have overturned dogma, provoked reevaluation of cellular plasticity in the mature brain and raised hopes for novel approaches to brain repair. Recent discoveries reveal that neurogenesis is regulated by environmental stimuli and can be responsive to brain injury. This cellular plasticity may indicate a possible endogenous repair program.

Daniel A. Peterson

2002-01-01

33

Structural Plasticity and Hippocampal Function  

PubMed Central

The hippocampus is a region of the mammalian brain that shows an impressive capacity for structural reorganization. Preexisting neural circuits undergo modifications in dendritic complexity and synapse number, and entirely novel neural connections are formed through the process of neurogenesis. These types of structural change were once thought to be restricted to development. However, it is now generally accepted that the hippocampus remains structurally plastic throughout life. This article reviews structural plasticity in the hippocampus over the lifespan, including how it is investigated experimentally. The modulation of structural plasticity by various experiential factors as well as the possible role it may have in hippocampal functions such as learning and memory, anxiety, and stress regulation are also considered. Although significant progress has been made in many of these areas, we highlight some of the outstanding issues that remain.

Leuner, Benedetta; Gould, Elizabeth

2010-01-01

34

Brain Development and CNS Plasticity  

Microsoft Academic Search

\\u000a Since the first developmental studies using fMRI there has been an almost logarithmic growth of investigations regarding functional\\u000a brain development. This growing knowledge, in combination with landmark animal studies of developmental neuroplasticity, has\\u000a provided us with significant insight into the nature of brain development and how brain maturation might map onto behavior.\\u000a Throughout this chapter we discuss how a number

Damien A. Fair; Bradley L. Schlaggar

35

Plasticity of language-related brain function during recovery from stroke  

Microsoft Academic Search

Background and Purpose-This study was undertaken to correlate functional recovery from aphasia after acute stroke with the temporal evolution of the anatomic, physiological, and functional changes as measured by MRI. Methods-Blood oxygenation level-dependent contrast and echo-planar MRI were used to map language comprehension in 6 normal adults and in 2 adult patients during recovery from acute stroke presenting with aphasia.

K R Thulborn; P A Carpenter; M A Just

1999-01-01

36

Bridging from Cells to Cognition in Autism Pathophysiology: Biological Pathways to Defective Brain Function and Plasticity  

Microsoft Academic Search

We review evidence to support the model that autism may begin when a maternal environmental, infectious, or autoantibody insult causes inflammation which increases reactive oxygen species (ROS) production in the fetus, leading to fetal DNA damage (nuclear and mitochondrial), and that these inflammatory and oxidative stressors persist beyond early development (with potential further exacerbations), producing ongoing functional consequences. In organs

Matthew P. Anderson; Brian S. Hooker; Martha R. Herbert

2008-01-01

37

Evolutionary Perspectives on Language and Brain Plasticity.  

ERIC Educational Resources Information Center

|This review discusses how general principles of brain development have contributed to both human brain plasticity and the acquisition of the human capacity for speech. Specifically, the role played by plastic developmental processes in the evolution and development of articulate control over vocalization in speech is examined. (Contains…

Deacon, Terrence W.

2000-01-01

38

Brain plasticity: From pathophysiological mechanisms to therapeutic applications  

Microsoft Academic Search

Cerebral plasticity, which is the dynamic potential of the brain to reorganize itself during ontogeny, learning, or following damage, has been widely studied in the last decade, in vitro, in animals, and also in humans since the development of functional neuroimaging. In the first part of this review, the main hypotheses about the pathophysiological mechanisms underlying plasticity are presented. At

Hugues Duffau

2006-01-01

39

Brain Plasticity and Stroke Rehabilitation  

Microsoft Academic Search

Neuronal connections and cortical maps are continuously remodeled by our experience. Knowledge of the potential capabilityof the brain to compensate for lesions is a prerequisite for optimal stroke rehabilitation strategies. Experimental focal cortical lesions induce changes in adjacent cortex and in the contralateral hemisphere. Neuroimaging studies in stroke patients indicate altered poststroke activation patterns, which suggest some functional reorganization. To

Barbro B. Johansson

2010-01-01

40

Ubiquitination in Postsynaptic Function and Plasticity  

PubMed Central

Neurons are highly specialized cells whose connectivity at synapses subserves rapid information transfer in the brain. Proper information processing, learning, and memory storage in the brain requires continuous remodeling of synaptic networks. Such remodeling includes synapse formation, elimination, synaptic protein turnover, and changes in synaptic transmission. An emergent mechanism for regulating synapse function is posttranslational modification through the ubiquitin pathway at the postsynaptic membrane. Here, we discuss recent findings implicating ubiquitination and protein degradation in postsynaptic function and plasticity. We describe postsynaptic ubiquitination pathways and their role in brain development, neuronal physiology, and brain disorders.

Mabb, Angela M.; Ehlers, Michael D.

2011-01-01

41

SAHA Enhances Synaptic Function and Plasticity In Vitro but Has Limited Brain Availability In Vivo and Does Not Impact Cognition  

PubMed Central

Suberoylanilide hydroxamic acid (SAHA) is an inhibitor of histone deacetylases (HDACs) used for the treatment of cutaneous T cell lymphoma (CTCL) and under consideration for other indications. In vivo studies suggest reducing HDAC function can enhance synaptic function and memory, raising the possibility that SAHA treatment could have neurological benefits. We first examined the impacts of SAHA on synaptic function in vitro using rat organotypic hippocampal brain slices. Following several days of SAHA treatment, basal excitatory but not inhibitory synaptic function was enhanced. Presynaptic release probability and intrinsic neuronal excitability were unaffected suggesting SAHA treatment selectively enhanced postsynaptic excitatory function. In addition, long-term potentiation (LTP) of excitatory synapses was augmented, while long-term depression (LTD) was impaired in SAHA treated slices. Despite the in vitro synaptic enhancements, in vivo SAHA treatment did not rescue memory deficits in the Tg2576 mouse model of Alzheimer’s disease (AD). Along with the lack of behavioral impact, pharmacokinetic analysis indicated poor brain availability of SAHA. Broader assessment of in vivo SAHA treatment using high-content phenotypic characterization of C57Bl6 mice failed to demonstrate significant behavioral effects of up to 150 mg/kg SAHA following either acute or chronic injections. Potentially explaining the low brain exposure and lack of behavioral impacts, SAHA was found to be a substrate of the blood brain barrier (BBB) efflux transporters Pgp and Bcrp1. Thus while our in vitro data show that HDAC inhibition can enhance excitatory synaptic strength and potentiation, our in vivo data suggests limited brain availability may contribute to the lack of behavioral impact of SAHA following peripheral delivery. These results do not predict CNS effects of SAHA during clinical use and also emphasize the importance of analyzing brain drug levels when interpreting preclinical behavioral pharmacology.

Hanson, Jesse E.; La, Hank; Plise, Emile; Chen, Yung-Hsiang; Ding, Xiao; Hanania, Taleen; Sabath, Emily V.; Alexandrov, Vadim; Brunner, Dani; Leahy, Emer; Steiner, Pascal; Liu, Lichuan; Scearce-Levie, Kimberly; Zhou, Qiang

2013-01-01

42

A role for sleep in brain plasticity  

Microsoft Academic Search

The idea that sleep might be involved in brain plasticity has been investigated for many years through a large number of animal and human studies, but evidence remains fragmentary. Large amounts of sleep in early life suggest that sleep may play a role in brain maturation. In particular, the influence of sleep in developing the visual system has been highlighted.

T. T. Dang-Vu; M. Desseilles; P. Peigneux; P. Maquet

2006-01-01

43

Brain Development, Plasticity, and Behavior  

Microsoft Academic Search

Damage to the infant brain is associated with a complex array of behavioral and anatomical effects. Recent research is leading to a new understanding of the nature of, and mechanisms underlying, recovery from brain damage.

Bryan Kolb

1989-01-01

44

Evidence for potentials and limitations of brain plasticity using an atlas of functional resectability of WHO grade II gliomas: Towards a “minimal common brain  

Microsoft Academic Search

Despite recent advances in non-invasive brain mapping imaging, the resectability of a given area in a patient harboring a WHO grade II glioma cannot be predicted preoperatively with high reliability, due to mechanisms of functional reorganization. Therefore, intraoperative mapping by direct electrical stimulation remains the gold standard for detection and preservation of eloquent areas during glioma surgery, because it enables

Tamara Ius; Elsa Angelini; Michel Thiebaut de Schotten; Emmanuel Mandonnet; Hugues Duffau

2011-01-01

45

Plasticity and Injury in the Developing Brain  

PubMed Central

The child’s brain is more malleable or plastic than that of adults and this accounts for the ability of children to learn new skills quickly or recovery from brain injuries. Several mechanisms contribute to this ability including overproduction and deletion of neurons and synapses, and activity-dependent stabilization of synapses. The molecular mechanisms for activity dependent synaptic plasticity are being discovered and this is leading to a better understanding of the pathogenesis of several disorders including neurofibromatosis, tuberous sclerosis, Fragile X syndrome and Rett syndrome. Many of the same pathways involved in synaptic plasticity, such as glutamate-mediated excitation, can also mediate brain injury when the brain is exposed to stress or energy failure such as hypoxia-ischemia. Recent evidence indicates that cell death pathways activated by injury differ between males and females. This new information about the molecular pathways involved in brain plasticity and injury are leading to insights that will provide better therapies for pediatric neurological disorders.

JOHNSTON, Michael V.; ISHIDA, Akira; ISHIDA, Wako Nakajima; MATSUSHITA, Hiroko Baber; NISHIMURA, Akira; TSUJI, Masahiro

2009-01-01

46

Sensory rehabilitation in the plastic brain.  

PubMed

The purpose of this review is to consider new sensory rehabilitation avenues in the context of the brain's remarkable ability to reorganize itself following sensory deprivation. Here, deafness and blindness are taken as two illustrative models. Mainly, two promising rehabilitative strategies based on opposing theoretical principles will be considered: sensory substitution and neuroprostheses. Sensory substitution makes use of the remaining intact senses to provide blind or deaf individuals with coded information of the lost sensory system. This technique thus benefits from added neural resources in the processing of the remaining senses resulting from crossmodal plasticity, which is thought to be coupled with behavioral enhancements in the intact senses. On the other hand, neuroprostheses represent an invasive approach aimed at stimulating the deprived sensory system directly in order to restore, at least partially, its functioning. This technique therefore relies on the neuronal integrity of the brain areas normally dedicated to the deprived sense and is rather hindered by the compensatory reorganization observed in the deprived cortex. Here, we stress that our understanding of the neuroplastic changes that occur in sensory-deprived individuals may help guide the design and the implementation of such rehabilitative methods. PMID:21741554

Collignon, Olivier; Champoux, François; Voss, Patrice; Lepore, Franco

2011-01-01

47

Construction of efficacious gait and upper limb functional interventions based on brain plasticity evidence and model-based measures for stroke patients.  

PubMed

For neurorehabilitation to advance from art to science, it must become evidence-based. Historically, there has been a dearth of evidence from which to construct rehabilitation interventions that are properly framed, accurately targeted, and credibly measured. In many instances, evidence of treatment response has not been sufficiently robust to demonstrate a change in function that is clinically, statistically, and economically important. Research evidence of activity-dependent central nervous system (CNS) plasticity and the requisite motor learning principles can be used to construct an efficacious motor recovery intervention. Brain plasticity after stroke refers to the regeneration of brain neuronal structures and/or reorganization of the function of neurons. Not only can CNS structure and function change in response to injury, but also, the changes may be modified by "activity". For gait training or upper limb functional training for stroke survivors, the "activity" is motor behavior, including coordination and strengthening exercise and functional training that comprise motor learning. Critical principles of motor learning required for CNS activity-dependent plasticity include: close-to-normal movements, muscle activation driving practice of movement; focused attention, repetition of desired movements, and training specificity. The ultimate goal of rehabilitation is to restore function so that a satisfying quality of life can be experienced. Accurate measurement of dysfunction and its underlying impairments are critical to the development of accurately targeted interventions that are sufficiently robust to produce gains, not only in function, but also in quality of life. The Classification of Functioning, Disability, and Health Model (ICF) model of disablement, put forth by the World Health Organization, can provide not only some guidance in measurement level selection, but also can serve as a guide to incorporate function and quality of life enhancement as the ultimate goals of rehabilitation interventions. Based on the evidence and principles of activity-dependent plasticity and motor learning, we developed gait training and upper limb functional training protocols. Guided by the ICF model, we selected and developed measures with characteristics rendering them most likely to capture change in the targeted aspects of intervention, as well as measures having membership not only in the impairment, but also in the functional or life role participation levels contained in the ICF model. We measured response to innovative gait training using a knee flexion coordination measure, coefficient of coordination consistency (ACC) of relative hip/knee (H/K) movement across multiple steps (H/K ACC), and milestones of participation in life role activities. We measured response to upper limb functional training according to measures designed to quantify functional gains in response to treatment targeted at wrist/hand or shoulder elbow training (Arm Motor Ability Test for wrist/hand (AMAT W/H) or shoulder/elbow (AMAT S/E)). We found that there was a statistically significant advantage for adding FES-IM gait training to an otherwise comparable and comprehensive gait training, according to the following measures: H/K ACC, the measure of consistently executed hip/knee coordination during walking; a specific measure of isolated joint knee flexion coordination; and a measure of multiple coordinated gait components. Further, enhanced gains in gait component coordination were robust enough to result in achievement of milestones in participation in life role activities. In the upper limb functional training study, we found that robotics + motor learning (ROB ML; shoulder/elbow robotics practice plus motor learning) produced a statistically significant gain in AMAT S/E; whereas functional electrical stimulation + motor learning (FES ML) did not. We found that FES ML (wrist/hand FES plus motor learning) produced a statistically significant gain in AMAT W/H; whereas ROB ML did not. These results together, support the phenome

Daly, Janis J; Ruff, Robert L

2007-12-20

48

Do some neurological conditions induce brain plasticity processes?  

PubMed

Paillard [Paillard J. Réflexions sur l'usage du concept de plasticité en Neurobiologie. J Psychol Norm Pathol 1976;1:33-47] defined adaptive plasticity as the capacity of the system to change its own structure and expand its behavioural repertoire. We review the literature on brain damage patients, in whom, adaptive plasticity was observed via neuropsychological and functional neuroimaging examinations. Attentional and memory system alterations and some resulting changes considered as compensatory mechanisms are commented. We have selected a single case presenting with developmental amnesia [Vargha-Khadem F, Gadian DG, Watkins KE, Connelly A, Van Paesschen W, Mishkin M. Differential effects of early hippocampal pathology on episodic and semantic memory. Science 1997;277(5324):376-80; Maguire EA, Vargha-Khadem F, Mishkin M. The effects of bilateral hippocampal damage on fMRI regional activations and interactions during memory retrieval. Brain 2001;124(Pt 6):1156-70] and several groups of multiple sclerosis patients studied recently [e.g. Mainero C, Pantano P, Caramia F, Pozzilli C. Brain reorganization during attention and memory tasks in multiple sclerosis: insights from functional MRI studies. J Neurol Sci 2006;245(1/2):93-8; Morgen K, Sammer G, Courtney SM, Wolters T, Melchior H, Blecker CR, et al. Distinct mechanisms of altered brain activation in patients with multiple sclerosis. Neuroimage 2007;37(3):937-46; Nebel K, Wiese H, Seyfarth J, Gizewski ER, Stude P, Diener HC, et al. Activity of attention related structures in multiple sclerosis patients. Brain Res 2007;1151:150-60]. Convergence evidence via the two approaches - neuropsychological and functional fMRI - was shown as functional and structural brain plasticity was demonstrated in the selected works. Some common characteristics of brain plasticity emerge from this review independently of the neurological conditions we reviewed. PMID:18479763

Manning, Lilianne

2008-04-06

49

Neuronal avalanches and brain plasticity  

NASA Astrophysics Data System (ADS)

Networks of living neurons exhibit an avalanche mode of activity, experimentally found in organotypic cultures. Moreover, experimental studies of morphology indicate that neurons develop a network of small-world-like connections, with the possibility of a very high connectivity degree. Here we discuss a recent model based on self-organized criticality, which consists of an electrical network with threshold firing and activity-dependent synapse strengths. The model is implemented on regular and small world lattices and on a scale-free network, the Apollonian network. The system exhibits an avalanche activity with a power law distribution of sizes and durations. The analysis of the power spectra of the electrical signal reproduces very robustly the power law behaviour with the exponent 0.8, experimentally measured in electroencephalogram (EEG) spectra. The exponents are found to be quite stable with respect to initial configurations and strength of plastic remodelling, indicating that universality holds for a wide class of neural network models.

de Arcangelis, L.; Herrmann, H. J.; Perrone-Capano, C.

2007-12-01

50

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

51

Effects of psychotropic drugs on brain plasticity in humans.  

PubMed

Although neurotransmitter-based hypotheses still prevail current thinking about the mechanism of action of psychotropic drugs, recent insight into the pathophysiology of psychiatric disorders has unveiled a range of new therapeutic actions of the drugs used to treat those disorders. Especially antidepressants seem to exert at least some of their effects via restoration of synaptic/neuronal plasticity. In addition, there is increasing evidence that several of the second-generation antipsychotics and some anticonvulsants affect neuronal survival/apoptosis as well as synaptic plasticity. Most of this evidence stems from work in animals. In this review, we will focus on the evidence for neuroplastic effects of psychotropic drugs in humans being aware of the fact that most of the data are derived from animals and that volumetric studies in humans can only indicate structural plasticity and not necessarily functional plasticity. However, as the data from human studies are rather poor and inconclusive, and sometimes even conflicting, it seems impossible to draw genereal conclusions. Until now studies on neuroplasticity in humans can only explain small pieces of the effects of pschotropic drugs on brain plasticity in humans. Nevertheless, future prospects for the development of new drugs targeting brain plasticity will be of importance and will complete this overview. PMID:23603440

Paulzen, Michael; Gründer, Gerhard

2013-04-01

52

Searching for Factors Underlying Cerebral Plasticity in the Normal and Injured Brain  

ERIC Educational Resources Information Center

|Brain plasticity refers to the capacity of the nervous system to change its structure and ultimately its function over a lifetime. There have been major advances in our understanding of the principles of brain plasticity and behavior in laboratory animals and humans. Over the past decade there have been advances in the application of these…

Kolb, Bryan; Muhammad, Arif; Gibb, Robbin

2011-01-01

53

Ethanol and brain plasticity: receptors and molecular networks of the postsynaptic density as targets of ethanol  

Microsoft Academic Search

Brain plasticity refers to the ability of the brain to undergo structural and functional changes. It is a necessary process that allows us to adapt and learn from our environment and is fundamental to our survival. However, under certain conditions, these neuroadaptive responses can have adverse consequences. In particular, increasing evidence indicates that plastic processes are coopted by drugs of

L. Judson Chandler

2003-01-01

54

Contrasting acute and slow-growing lesions: a new door to brain plasticity  

Microsoft Academic Search

The concept of plasticity describes the mechanisms that rearrange cerebral organization following a brain injury. During the last century, plasticity has been mainly investigated in humans with acute strokes. It was then shown: (i) that the brain is organized into highly specialized functional areas, often designated 'eloquent' areas and (ii) that a lesion within the eloquent area gives rise to

Michel Desmurget; Francois Bonnetblanc; Hugues Duffau

2006-01-01

55

Contrasting Acute and Slow-Growing Lesions: A New Door to Brain Plasticity  

ERIC Educational Resources Information Center

|The concept of plasticity describes the mechanisms that rearrange cerebral organization following a brain injury. During the last century, plasticity has been mainly investigated in humans with acute strokes. It was then shown: (i) that the brain is organized into highly specialized functional areas, often designated "eloquent" areas and (ii)…

Desmurget, Michel; Bonnetblanc, FranCois; Duffau, Hugues

2007-01-01

56

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

57

NREM Sleep Oscillations and Brain Plasticity in Aging  

PubMed Central

The human electroencephalogram (EEG) during non-rapid eye movement sleep (NREM) is characterized mainly by high-amplitude (>75??V), slow-frequency (<4?Hz) waves (slow waves), and sleep spindles (?11–15?Hz; >0.25?s). These NREM oscillations play a crucial role in brain plasticity, and importantly, NREM sleep oscillations change considerably with aging. This review discusses the association between NREM sleep oscillations and cerebral plasticity as well as the functional impact of age-related changes on NREM sleep oscillations. We propose that age-related reduction in sleep-dependent memory consolidation may be due in part to changes in NREM sleep oscillations.

Fogel, Stuart; Martin, Nicolas; Lafortune, Marjolaine; Barakat, Marc; Debas, Karen; Laventure, Samuel; Latreille, Veronique; Gagnon, Jean-Francois; Doyon, Julien; Carrier, Julie

2012-01-01

58

Plasticity in the adult brain: lessons from the visual system  

Microsoft Academic Search

While cortical circuits display maximal sensitivity to sensory experience during critical periods of early postnatal development,\\u000a far less plasticity is present in the mature brain. Ocular dominance shift of visual cortical neurons in response to eye occlusion\\u000a and recovery of visual functions from a period of sensory deprivation are two classical models in the study of critical period\\u000a determinants in

Maria Spolidoro; Alessandro Sale; Nicoletta Berardi; Lamberto Maffei

2009-01-01

59

Plasticity of nonneuronal brain tissue: roles in developmental disorders.  

PubMed

Neuronal and nonneuronal plasticity are both affected by environmental and experiential factors. Remodeling of existing neurons induced by such factors has been observed throughout the brain, and includes alterations in dendritic field dimensions, synaptogenesis, and synaptic morphology. The brain loci affected by these plastic neuronal changes are dependent on the type of experience and learning. Increased neurogenesis in the hippocampal dentate gyrus is a well-documented response to environmental complexity ("enrichment") and learning. Exposure to challenging experiences and learning opportunities also alters existing glial cells (i.e., astrocytes and oligodendrocytes), and up-regulates gliogenesis, in the cerebral cortex and cerebellum. Such glial plasticity often parallels neuronal remodeling in both time and place, and this enhanced morphological synergism may be important for optimizing the functional interaction between glial cells and neurons. Aberrant structural plasticity of nonneuronal elements is a contributing factor, as is aberrant neuron plasticity, to neurological and developmental disorders such as epilepsy, autism, and mental retardation (i.e., fragile X syndrome). Some of these nonneuronal pathologies include abnormal cerebral and cerebellar white matter and myelin-related proteins in autism; abnormal myelin basic protein in fragile X syndrome (FXS); and abnormal astrocytes in autism, FXS, and epilepsy. A number of recent studies demonstrate the possibility of using environmental and experiential intervention to reduce or ameliorate some of the neuronal and nonneuronal abnormalities, as well as behavioral deficits, present in these neurological and developmental disorders. PMID:15362161

Dong, Willie K; Greenough, William T

2004-01-01

60

Motor rehabilitation and brain plasticity after hemiparetic stroke  

Microsoft Academic Search

This review intends to begin to build a bridge between our understanding of the effect of motor rehabilitation and brain plasticity on recovery after hemiparetic stroke. It discusses the impact of intensive post-stroke motor rehabilitation on motor recovery. This is followed by an overview of our current understanding, based on human brain mapping technologies, of brain plasticity underlying spontaneous recovery

Judith D. Schaechter; A. Martinos

2004-01-01

61

Relating Brain Damage to Brain Plasticity in Patients With Multiple Sclerosis  

PubMed Central

Background Failure of adaptive plasticity with increasing pathology is suggested to contribute to progression of disability in multiple sclerosis (MS). However, functional impairments can be reduced with practice, suggesting that brain plasticity is preserved even in patients with substantial damage. Objective Here, functional magnetic resonance imaging (fMRI) was used to probe systems-level mechanisms of brain plasticity associated with improvements in visuomotor performance in MS patients and related to measures of microstructural damage. Methods 23 MS patients and 12 healthy controls underwent brain fMRI during the first practice session of a visuomotor task (short-term practice) and after 2 weeks of daily practice with the same task (longer-term practice). Participants also underwent a structural brain MRI scan. Results Patients performed more poorly than controls at baseline. Nonetheless, with practice, patients showed performance improvements similar to controls and independent of the extent of MRI measures of brain pathology. Different relationships between performance improvements and activations were found between groups: greater short-term improvements were associated with lower activation in the sensorimotor, posterior cingulate, and parahippocampal cortices for patients, whereas greater long-term improvements correlated with smaller activation reductions in the visual cortex of controls. Conclusions Brain plasticity for visuomotor practice is preserved in MS patients despite a high burden of cerebral pathology. Cognitive systems different from those acting in controls contribute to this plasticity in patients. These findings challenge the notion that increasing pathology is accompanied by an outright failure of adaptive plasticity, supporting a neuroscientific rationale for recovery-oriented strategies even in chronically disabled patients.

Tomassini, Valentina; Johansen-Berg, Heidi; Jbabdi, Saad; Wise, Richard G.; Pozzilli, Carlo; Palace, Jacqueline; Matthews, Paul M.

2013-01-01

62

[Genome, environment and plasticity of the brain underlying individual adaptation].  

PubMed

Epigenetic mechanisms mediate the interaction between environment and genome. On molecular level, these mechanisms are active in plastic processes of the brain and influence brain function and the person's ability to adapt to the environment. Genomic variations provide individual options for this adaptation, and a spectrum of behavioral patterns necessary for species preservation. Adaptation processes may also be harmful in respect of individual health, leading even to psychiatric illnesses, but are still meaningful as seen through the person's inner experience, genome or environment. PMID:22320103

Paunio, Tiina

2011-01-01

63

Regeneration and plasticity in the brain and spinal cord  

Microsoft Academic Search

The concept of brain plasticity covers all the mechanisms involved in the capacity of the brain to adjust and remodel itself in response to environmental requirements, experience, skill acquisition, and new challenges including brain lesions. Advances in neuroimaging and neurophysiologic techniques have increased our knowledge of task-related changes in cortical representation areas in the intact and injured human brain. The

Barbro B Johansson

2007-01-01

64

Plasticity of Nonneuronal Brain Tissue: Roles in Developmental Disorders  

ERIC Educational Resources Information Center

|Neuronal and nonneuronal plasticity are both affected by environmental and experiential factors. Remodeling of existing neurons induced by such factors has been observed throughout the brain, and includes alterations in dendritic field dimensions, synaptogenesis, and synaptic morphology. The brain loci affected by these plastic neuronal changes…

Dong, Willie K.; Greenough, William T.

2004-01-01

65

Plasticity in the Developing Brain: Implications for Rehabilitation  

ERIC Educational Resources Information Center

|Neuronal plasticity allows the central nervous system to learn skills and remember information, to reorganize neuronal networks in response to environmental stimulation, and to recover from brain and spinal cord injuries. Neuronal plasticity is enhanced in the developing brain and it is usually adaptive and beneficial but can also be maladaptive…

Johnston, Michael V.

2009-01-01

66

[Complete Brain-machine Interfaces and Plastic Changes in the Brain].  

PubMed

Brain-machine interfaces (BMIs) are artificial systems that control external devices or body muscles with signals generated by the neural activities of working brains. The BMIs currently under development can be divided into 2 types,i.e.,conventional (noninvasive) BMIs and complete (invasive) BMIs. Only the latter type of BMI can ultimately be used in the future. This paper describes some recent studies on invasive BMI using monkeys as subjects and discusses the progress of and problems revealed in these studies. The focus then shifts to plastic changes in neuronal activities caused by the BMIs. When a BMI is in use,the brain inevitably changes its own functions and structures in order to operate external devices more efficiently. Therefore,basic research on BMIs inevitably involves study on neural plasticity; such research is essential for further development of neurorehabilitation and for high performance of BMIs. This paper describes 2 recent pioneering BMI studies-one involving the rat motor cortex and the other involving the monkey primary motor cortex. Both studies revealed rapid and plastic changes in neuronal function during the period the animals were learning to operate external devices with the BMIs. The fact that the neuronal changes were caused by the contingency of neuronal activity and rewards emphasizes the significance of the neural-operant paradigm for research on neuronal plasticity in BMIs. The present paper describes a neural-operant experiment involving a recently developed high-performance BMI system and reports rapid and plastic changes in firing frequency and synchrony of the hippocampal neurons in both adult and aged rats. Finally,the paper suggests that complete BMIs can be developed by neuroscience research and should be able to unmask the enigmas of the neural code,brain-body interaction,and ongoing activity in the working brain. PMID:20940505

Sakurai, Yoshio

2010-10-01

67

Brain foods: the effects of nutrients on brain function  

PubMed Central

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

Gomez-Pinilla, Fernando

2009-01-01

68

Measuring and inducing brain plasticity in chronic aphasia  

PubMed Central

Brain plasticity associated with anomia recovery in aphasia is poorly understood. Here, I review four recent studies from my lab that focused on brain modulation associated with long-term anomia outcome, its behavioral treatment, and the use of transcranial brain stimulation to enhance anomia treatment success in individuals with chronic aphasia caused by left hemisphere stroke. In a study that included 15 participants with aphasia who were compared to a group of 10 normal control subjects, we found that improved naming ability was associated with increased left hemisphere activity. A separate study (N=26) revealed similar results in that improved anomia treatment outcome was associated with increased left hemisphere recruitment. Taken together, these two studies suggest that improved naming in chronic aphasia relies on the damaged left hemisphere. Based on these findings, we conducted two studies to appreciate the effect of using low current transcranial electrical stimulation as an adjuvant to behavioral anomia treatment. Both studies yielded positive findings in that anomia treatment outcome was improved when it was coupled with real brain stimulation as compared with a placebo (sham) condition. Overall, these four studies support the notion that the intact cortex in the lesioned left hemisphere supports anomia recovery in aphasia. Learning outcomes: Readers will (a) be able to appreciate the possible influence of animal research upon the understanding of brain plasticity induced by aphasia treatment, (b) understand where functional changes associated with anomia treatment occur in the brain, (c) understand the basic principles of transcranial direct current stimulation, and (d) understand how brain stimulation coupled with aphasia treatment may potentially improve treatment outcome.

Fridriksson, Julius

2011-01-01

69

Brain Plasticity and Recovery from Stroke  

Microsoft Academic Search

The brain has a remarkable ability to reorganize itself throughout the human life span. The most extraordinary example may be the remodeling of the cerebral cortex after an injury in which a large part of it simply dies. It is not uncommon for stroke patients who have lost the ability to speak or to move a limb to regain function

Nina P. Azari; Rüdiger J. Seitz

2000-01-01

70

Physical activity, brain plasticity, and Alzheimer's disease.  

PubMed

In this review we summarize the epidemiological, cross-sectional, and interventional studies examining the association between physical activity and brain volume, function, and risk for Alzheimer's disease. The epidemiological literature provides compelling evidence that greater amounts of physical activity are associated with a reduced risk of dementia in late life. In addition, randomized interventions using neuroimaging tools have reported that participation in physical activity increases the size of prefrontal and hippocampal brain areas, which may lead to a reduction in memory impairments. Consistent with these findings, longitudinal studies using neuroimaging tools also find that the volume of prefrontal and hippocampal brain areas are larger in individuals who engaged in more physical activity earlier in life. We conclude from this review that there is convincing evidence that physical activity has a consistent and robust association with brain regions implicated in age-related cognitive decline and Alzheimer's disease. In addition to summarizing this literature we provide recommendations for future research on physical activity and brain health. PMID:23085449

Erickson, Kirk I; Weinstein, Andrea M; Lopez, Oscar L

2012-10-16

71

Measuring and Inducing Brain Plasticity in Chronic Aphasia  

ERIC Educational Resources Information Center

|Brain plasticity associated with anomia recovery in aphasia is poorly understood. Here, I review four recent studies from my lab that focused on brain modulation associated with long-term anomia outcome, its behavioral treatment, and the use of transcranial brain stimulation to enhance anomia treatment success in individuals with chronic aphasia…

Fridriksson, Julius

2011-01-01

72

Neural Plasticity and Neurorehabilitation: Teaching the New Brain Old Tricks  

ERIC Educational Resources Information Center

|Following brain injury or disease there are widespread biochemical, anatomical and physiological changes that result in what might be considered a new, very different brain. This adapted brain is forced to reacquire behaviors lost as a result of the injury or disease and relies on neural plasticity within the residual neural circuits. The same…

Kleim, Jeffrey A.

2011-01-01

73

Split Brain Functioning.  

ERIC Educational Resources Information Center

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

Cassel, Russell N.

1978-01-01

74

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...

75

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

ERIC Educational Resources Information Center

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

Omarzu, Julia

2004-01-01

76

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

ERIC Educational Resources Information Center

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

Omarzu, Julia

2004-01-01

77

Do children really recover better? Neurobehavioural plasticity after early brain insult.  

PubMed

Plasticity is an intrinsic property of the central nervous system, reflecting its capacity to respond in a dynamic manner to the environment and experience via modification of neural circuitry. In the context of healthy development, plasticity is considered beneficial, facilitating adaptive change in response to environmental stimuli and enrichment, with research documenting establishment of new neural connections and modification to the mapping between neural activity and behaviour. Less is known about the impact of this plasticity in the context of the young, injured brain. This review seeks to explore plasticity processes in the context of early brain insult, taking into account historical perspectives and building on recent advances in knowledge regarding ongoing development and recovery following early brain insult, with a major emphasis on neurobehavioural domains. We were particularly interested to explore the way in which plasticity processes respond to early brain insult, the implications for functional recovery and how this literature contributes to the debate between localization of brain function and neural network models. To this end we have provided an overview of normal brain development, followed by a description of the biological mechanisms associated with the most common childhood brain insults, in order to explore an evidence base for considering the competing theoretical perspectives of early plasticity and early vulnerability. We then detail these theories and the way in which they contribute to our understanding of the consequences of early brain insult. Finally, we examine evidence that considers key factors (e.g. insult severity, age at insult, environment) that may act, either independently or synergistically, to influence recovery processes and ultimate outcome. We conclude that neither plasticity nor vulnerability theories are able to explain the range of functional outcomes from early brain insult. Rather, they represent extremes along a 'recovery continuum'. Where a child's outcome falls along this continuum depends on injury factors (severity, nature, age) and environmental influences (family, sociodemographic factors, interventions). PMID:21784775

Anderson, Vicki; Spencer-Smith, Megan; Wood, Amanda

2011-07-22

78

Brain plasticity in Diptera and Hymenoptera  

PubMed Central

To mediate different types of behaviour, nervous systems must coordinate the proper operation of their neural circuits as well as short- and long-term alterations that occur within those circuits. The latter ultimately devolve upon specific changes in neuronal structures, membrane properties and synaptic connections that are all examples of plasticity. This reorganization of the adult nervous system is shaped by internal and external influences both during development and adult maturation. In adults, behavioural experience is a major driving force of neuronal plasticity studied particularly in sensory systems. The range of adaptation depends on features that are important to a particular species, so that learning is essential for foraging in honeybees, while regenerative capacities are important in hemimetabolous insects with long appendages. Experience is usually effective during a critical period in early adult life, when neural function becomes tuned to future conditions in an insect's life. Changes occur at all levels, in synaptic circuits, neuropile volumes, and behaviour. There are many examples, and this review incorporates only a select few, mainly those from Diptera and Hymenoptera.

Groh, Claudia; Meinertzhagen, Ian A.

2010-01-01

79

Learning about time: plastic changes and interindividual brain differences.  

PubMed

Learning the timing of rapidly changing sensory events is crucial to construct a reliable representation of the environment and to efficiently control behavior. The neurophysiological mechanisms underlying the learning of time are unknown. We used functional and structural magnetic resonance imaging to investigate neurophysiological changes and individual brain differences underlying the learning of time in the millisecond range. We found that the representation of a trained visual temporal interval was associated with functional and structural changes in a sensory-motor network including occipital, parietal, and insular cortices, plus the cerebellum. We show that both types of neurophysiological changes correlated with changes of performance accuracy and that activity and gray-matter volume of sensorimotor cortices predicted individual learning abilities. These findings represent neurophysiological evidence of functional and structural plasticity associated with the learning of time in humans and highlight the role of sensory-motor circuits in the perceptual representation of time in the millisecond range. PMID:22920262

Bueti, Domenica; Lasaponara, Stefano; Cercignani, Mara; Macaluso, Emiliano

2012-08-23

80

Estrogens and phytoestrogens: brain plasticity of sexually dimorphic brain volumes  

Microsoft Academic Search

Sexually dimorphic brain volumes (sexually dimorphic nucleus of the preoptic area (SDN-POA) and anteroventral periventricular (AVPV) nucleus) are influenced by estrogens. Phytoestrogens, derived from plants (especially soy products), are molecules structurally and functionally similar to estradiol. The purpose of this study was to examine: the consumption of phytoestrogen (using a phytoestrogen-rich (Phyto-600) versus a phytoestrogen-free (Phyto-free)) diets from conception to

E. D Lephart; R. W Rhees; K. D. R Setchell; L. H Bu; T. D Lund

2003-01-01

81

Blindness and brain plasticity: contribution of mental imagery?  

Microsoft Academic Search

The purpose of this study was to study brain plasticity in the visual cortex, in six subjects totally blind from birth. The protocol we used was the same as that employed in a prior study on blindfolded sighted subjects (Brain Res., 924 (2002) 176). The production of mental images from animal names versus passive listening to abstract words, involved, in

S Lambert; E Sampaio; Y Mauss; C Scheiber

2004-01-01

82

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

83

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

84

Dietary curcumin counteracts the outcome of traumatic brain injury on oxidative stress, synaptic plasticity, and cognition.  

PubMed

The pervasive action of oxidative stress on neuronal function and plasticity after traumatic brain injury (TBI) is becoming increasingly recognized. Here, we evaluated the capacity of the powerful antioxidant curry spice curcumin ingested in the diet to counteract the oxidative damage encountered in the injured brain. In addition, we have examined the possibility that dietary curcumin may favor the injured brain by interacting with molecular mechanisms that maintain synaptic plasticity and cognition. The analysis was focused on the BDNF system based on its action on synaptic plasticity and cognition by modulating synapsin I and CREB. Rats were exposed to a regular diet or a diet high in saturated fat, with or without 500 ppm curcumin for 4 weeks (n = 8/group), before a mild fluid percussion injury (FPI) was performed. The high-fat diet has been shown to exacerbate the effects of TBI on synaptic plasticity and cognitive function. Supplementation of curcumin in the diet dramatically reduced oxidative damage and normalized levels of BDNF, synapsin I, and CREB that had been altered after TBI. Furthermore, curcumin supplementation counteracted the cognitive impairment caused by TBI. These results are in agreement with previous evidence, showing that oxidative stress can affect the injured brain by acting through the BDNF system to affect synaptic plasticity and cognition. The fact that oxidative stress is an intrinsic component of the neurological sequel of TBI and other insults indicates that dietary antioxidant therapy is a realistic approach to promote protective mechanisms in the injured brain. PMID:16364299

Wu, Aiguo; Ying, Zhe; Gomez-Pinilla, Fernando

2005-12-20

85

Cognitive neural plasticity during learning and recovery from brain damage.  

PubMed

The process of neuroplasticity is the ability of the brain to change, either in response to experience or injury. It is a vital process both during normal development and for the recovery after brain injury. Recent research has emphasized that this takes place via both local restitution as well as reorganization and compensatory reassignment. The fact that the brain can undergo such plastic changes has provided evidence for what underlies developmental brain disorders, as well as the variable response to injury at different points in the lifespan. The factors affecting plasticity and its long-term consequences may have increasing importance in exposing the pattern of changes that occur in the normal brain with aging. PMID:17046672

Raymont, Vanessa; Grafman, Jordan

2006-01-01

86

Modulation of fibroblast growth factor-2 by stress and corticosteroids: from developmental events to adult brain plasticity  

Microsoft Academic Search

Neurotrophic factors are a heterogeneous group of peptides that play important roles on brain function at different development stages. Basic fibroblast growth factor (FGF-2), one of these molecules, is highly expressed in developing and adult brain. Its expression can be regulated under different experimental situations and this may be relevant for cellular vulnerability and brain plasticity. Stress and glucocorticoid hormones

Raffaella Molteni; Fabio Fumagalli; Valerio Magnaghi; Mila Roceri; Massimo Gennarelli; Giorgio Racagni; Roberto C Melcangi; Marco A Riva

2001-01-01

87

Imaging Brain Plasticity: Conceptual and Methodological Issues— A Theoretical Review  

Microsoft Academic Search

The neural plasticity associated with learning and development is increasingly being studied using functional neuroimaging methods such as positron emission tomography (PET) and functional magnetic resonance imaging (fMRI). In this paper I outline a set of conceptual and methodological issues that are particularly relevant for the study of neural plasticity. A number of confounds, related to changes in performance and

Russell A. Poldrack

2000-01-01

88

Mechanisms and Functional Brain Areas  

Microsoft Academic Search

Explanations of how psychological capacities are carried out often invoke functional brain areas. I argue that such explanations\\u000a cannot succeed. Psychological capacities are carried out by identifiable entities and their activities in the brain, but functional\\u000a brain areas are not the relevant entities. I proceed by assuming that if functional brain areas did carry out psychological\\u000a capacities, then these brain

Gregory Johnson

2009-01-01

89

BRAIN PLASTICITY AND HAND SURGERY: AN OVERVIEW  

Microsoft Academic Search

The hand is an extension of the brain, and the hand is projected and represented in large areas of the motor and sensory cortex. The brain is a complicated neural network which continuously remodels itself as a result of changes in sensory input. Such synaptic reorganizational changes may be activity-dependent, based on alterations in hand activity and tactile experience, or

G. LUNDBORG

2000-01-01

90

Brain Plasticity in Learning Visual Words  

Microsoft Academic Search

This study used event-related brain potentials and performance to trace changes in the underlying brain circuitry of undergraduates who spent 5 weeks learning a miniature artificial language. A reaction time task involving visual matching showed that words in the new language were processed like nonsense material before training, and like English words at the end of the 5 weeks of

Bruce D. McCandliss; Michael I. Posner; T. Givón

1997-01-01

91

Imaging neuroscience: Lessons from studies of brain plasticity  

Microsoft Academic Search

The non-invasive brain scanning techniques, introduced a quarter of a century ago, have become crucial for diagnosis in clinical neurology. They have also been used to investigate brain function and have provided information about normal activity and pathogenesis. They have been used to investigate functional specialisation in the brain and how specialised areas communicate to generate complex integrated functions such

Richard SJ Frackowiak

2002-01-01

92

Musical training induces functional plasticity in human hippocampus.  

PubMed

Training can change the functional and structural organization of the brain, and animal models demonstrate that the hippocampus formation is particularly susceptible to training-related neuroplasticity. In humans, however, direct evidence for functional plasticity of the adult hippocampus induced by training is still missing. Here, we used musicians' brains as a model to test for plastic capabilities of the adult human hippocampus. By using functional magnetic resonance imaging optimized for the investigation of auditory processing, we examined brain responses induced by temporal novelty in otherwise isochronous sound patterns in musicians and musical laypersons, since the hippocampus has been suggested previously to be crucially involved in various forms of novelty detection. In the first cross-sectional experiment, we identified enhanced neural responses to temporal novelty in the anterior left hippocampus of professional musicians, pointing to expertise-related differences in hippocampal processing. In the second experiment, we evaluated neural responses to acoustic temporal novelty in a longitudinal approach to disentangle training-related changes from predispositional factors. For this purpose, we examined an independent sample of music academy students before and after two semesters of intensive aural skills training. After this training period, hippocampal responses to temporal novelty in sounds were enhanced in musical students, and statistical interaction analysis of brain activity changes over time suggests training rather than predisposition effects. Thus, our results provide direct evidence for functional changes of the adult hippocampus in humans related to musical training. PMID:20107063

Herdener, Marcus; Esposito, Fabrizio; di Salle, Francesco; Boller, Christian; Hilti, Caroline C; Habermeyer, Benedikt; Scheffler, Klaus; Wetzel, Stephan; Seifritz, Erich; Cattapan-Ludewig, Katja

2010-01-27

93

Motor enrichment and the induction of plasticity before or after brain injury.  

PubMed

Voluntary exercise, treadmill activity, skills training, and forced limb use have been utilized in animal studies to promote brain plasticity and functional change. Motor enrichment may prime the brain to respond more adaptively to injury, in part by upregulating trophic factors such as GDNF, FGF-2, or BDNF. Discontinuation of exercise in advance of brain injury may cause levels of trophic factor expression to plummet below baseline, which may leave the brain more vulnerable to degeneration. Underfeeding and motor enrichment induce remarkably similar molecular and cellular changes that could underlie their beneficial effects in the aged or injured brain. Exercise begun before focal ischemic injury increases BDNF and other defenses against cell death and can maintain or expand motor representations defined by cortical microstimulation. Interfering with BDNF synthesis causes the motor representations to recede or disappear. Injury to the brain, even in sedentary rats, causes a small, gradual increase in astrocytic expression of neurotrophic factors in both local and remote brain regions. The neurotrophic factors may inoculate those areas against further damage and enable brain repair and use-dependent synaptogenesis associated with recovery of function or compensatory motor learning. Plasticity mechanisms are particularly active during time-windows early after focal cortical damage or exposure to dopamine neurotoxins. Motor and cognitive impairments may contribute to self-imposed behavioral impoverishment, leading to a reduced plasticity. For slow degenerative models, early forced forelimb use or exercise has been shown to halt cell loss, whereas delayed rehabilitation training is ineffective and disuse is prodegenerative. However, it is possible that, in the chronic stages after brain injury, a regimen of exercise would reactivate mechanisms of plasticity and thus enhance rehabilitation targeting residual functional deficits. PMID:14584829

Kleim, Jeffrey A; Jones, Theresa A; Schallert, Timothy

2003-11-01

94

Synaptic plasticity in depression: molecular, cellular and functional correlates.  

PubMed

Synaptic plasticity confers environmental adaptability through modification of the connectivity between neurons and neuronal circuits. This is achieved through changes to synapse-associated signaling systems and supported by complementary changes to cellular morphology and metabolism within the tripartite synapse. Mounting evidence suggests region-specific changes to synaptic form and function occur as a result of chronic stress and in depression. Within subregions of the prefrontal cortex (PFC) and hippocampus structural and synapse-related findings seem consistent with a deficit in long-term potentiation (LTP) and facilitation of long-term depression (LTD), particularly at excitatory pyramidal synapses. Other brain regions are less well-studied; however the amygdala may feature a somewhat opposite synaptic pathology including reduced inhibitory tone. Changes to synaptic plasticity in stress and depression may correlate those to several signal transduction pathways (e.g. NOS-NO, cAMP-PKA, Ras-ERK, PI3K-Akt, GSK-3, mTOR and CREB) and upstream receptors (e.g. NMDAR, TrkB and p75NTR). Deficits in synaptic plasticity may further correlate disrupted brain redox and bioenergetics. Finally, at a functional level region-specific changes to synaptic plasticity in depression may relate to maladapted neurocircuitry and parallel reduced cognitive control over negative emotion. PMID:23268191

Marsden, W N

2012-12-23

95

How Cognitive Plasticity Resolves the Brain's Information Processing Dilemma.  

PubMed

A key unresolved question in cognitive science is whether the brain uses asynchronous or synchronous patterns of information transmission. Using an auditory learning task combined with electrophysiological recordings, we reveal for the first time that cognitive plasticity during learning transforms an asynchronous into a synchronous transmission pattern to achieve rapid, error-free performance. We also present a new model showing how the brain may resolve its information processing and transmission dilemma. PMID:24091591

Gong, Diankun; Ma, Weiyi; Kendrick, Keith M; Hu, Qingqing; Yao, Dezhong

2013-10-04

96

How Cognitive Plasticity Resolves the Brain's Information Processing Dilemma  

PubMed Central

A key unresolved question in cognitive science is whether the brain uses asynchronous or synchronous patterns of information transmission. Using an auditory learning task combined with electrophysiological recordings, we reveal for the first time that cognitive plasticity during learning transforms an asynchronous into a synchronous transmission pattern to achieve rapid, error-free performance. We also present a new model showing how the brain may resolve its information processing and transmission dilemma.

Gong, Diankun; Ma, Weiyi; Kendrick, Keith M.; Hu, Qingqing; Yao, Dezhong

2013-01-01

97

Differential pharmacological effects on brain reactivity and plasticity in Alzheimer's disease.  

PubMed

Acetylcholinesterase inhibitors (AChEIs) are the most commonly prescribed monotherapeutic medications for Alzheimer's disease (AD). However, their underlying neurophysiological effects remain largely unknown. We investigated the effects of monotherapy (AChEI) and combination therapy (AChEI and memantine) on brain reactivity and plasticity. Patients treated with monotherapy (AChEI) (N?=?7) were compared to patients receiving combination therapy (COM) (N?=?9) and a group of age-matched, healthy controls (HCs) (N?=?13). Cortical reactivity and plasticity of the motor cortex were examined using transcranial magnetic stimulation. Cognitive functions were assessed with the cognitive subscale of the Alzheimer Disease Assessment Scale-Cognitive Subscale (ADAS-Cog), activities of daily living (ADLs) with the ADCS-ADL. In addition we assessed the degree of brain atrophy by measuring brain-scalp distances in seven different brain areas. Patient groups differed in resting motor threshold and brain atrophy, with COM showing a lower motor threshold but less atrophy than AChEI. COM showed similar plasticity effects as the HC group, while plasticity was reduced in AChEI. Long-interval intracortical inhibition (LICI) was impaired in both patient groups when compared to HC. ADAS-Cog scores were positively correlated with LICI measures and with brain atrophy, specifically in the left inferior parietal cortex. AD patients treated with mono- or combination-therapy show distinct neurophysiological patterns. Further studies should investigate whether these measures might serve as biomarkers of treatment response and whether they could guide other therapeutic interventions. PMID:24109459

Brem, Anna-Katharine; Atkinson, Natasha J; Seligson, Erica E; Pascual-Leone, Alvaro

2013-10-07

98

Differential Pharmacological Effects on Brain Reactivity and Plasticity in Alzheimer's Disease  

PubMed Central

Acetylcholinesterase inhibitors (AChEIs) are the most commonly prescribed monotherapeutic medications for Alzheimer’s disease (AD). However, their underlying neurophysiological effects remain largely unknown. We investigated the effects of monotherapy (AChEI) and combination therapy (AChEI and memantine) on brain reactivity and plasticity. Patients treated with monotherapy (AChEI) (N?=?7) were compared to patients receiving combination therapy (COM) (N?=?9) and a group of age-matched, healthy controls (HCs) (N?=?13). Cortical reactivity and plasticity of the motor cortex were examined using transcranial magnetic stimulation. Cognitive functions were assessed with the cognitive subscale of the Alzheimer Disease Assessment Scale-Cognitive Subscale (ADAS-Cog), activities of daily living (ADLs) with the ADCS-ADL. In addition we assessed the degree of brain atrophy by measuring brain-scalp distances in seven different brain areas. Patient groups differed in resting motor threshold and brain atrophy, with COM showing a lower motor threshold but less atrophy than AChEI. COM showed similar plasticity effects as the HC group, while plasticity was reduced in AChEI. Long-interval intracortical inhibition (LICI) was impaired in both patient groups when compared to HC. ADAS-Cog scores were positively correlated with LICI measures and with brain atrophy, specifically in the left inferior parietal cortex. AD patients treated with mono- or combination-therapy show distinct neurophysiological patterns. Further studies should investigate whether these measures might serve as biomarkers of treatment response and whether they could guide other therapeutic interventions.

Brem, Anna-Katharine; Atkinson, Natasha J.; Seligson, Erica E.; Pascual-Leone, Alvaro

2013-01-01

99

Changes in liver mitochondrial plasticity induced by brain tumor  

PubMed Central

Background Accumulating data suggest that liver is a major target organ of systemic effects observed in the presence of a cancer. In this study, we investigated the consequences of the presence of chemically induced brain tumors in rats on biophysical parameters accounting for the dynamics of water in liver mitochondria. Methods Tumors of the central nervous system were induced by intraveinous administration of ethylnitrosourea (ENU) to pregnant females on the 19th day of gestation. The mitochondrial crude fraction was isolated from the liver of each animal and the dynamic parameters of total water and its macromolecule-associated fraction (structured water, H2Ost) were calculated from Nuclear Magnetic Resonance (NMR) measurements. Results The presence of a malignant brain tumor induced a loss of water structural order that implicated changes in the physical properties of the hydration shells of liver mitochondria macromolecules. This feature was linked to an increase in the membrane cholesterol content, a way to limit water penetration into the bilayer and then to reduce membrane permeability. As expected, these alterations in mitochondrial plasticity affected ionic exchanges and led to abnormal features of mitochondrial biogenesis and caspase activation. Conclusion This study enlightens the sensitivity of the structured water phase in the liver mitochondria machinery to external conditions such as tumor development at a distant site. The profound metabolic and functional changes led to abnormal features of ion transport, mitochondrial biogenesis and caspase activation.

Pouliquen, Daniel; Olivier, Christophe; Debien, Emilie; Meflah , Khaled; Vallette, Francois M; Menanteau, Jean

2006-01-01

100

Training the Brain: Practical Applications of Neural Plasticity From the Intersection of Cognitive Neuroscience, Developmental Psychology, and Prevention Science  

Microsoft Academic Search

Prior researchers have shown that the brain has a remarkable ability for adapting to environmental changes. The positive effects of such neural plasticity include enhanced functioning in specific cognitive domains and shifts in cortical representation following naturally occurring cases of sensory deprivation; however, maladaptive changes in brain function and development owing to early developmental adversity and stress have also been

Richard L. Bryck; Philip A. Fisher

2012-01-01

101

Plasticity of Brain Networks in a Randomized Intervention Trial of Exercise Training in Older Adults  

PubMed Central

Research has shown the human brain is organized into separable functional networks during rest and varied states of cognition, and that aging is associated with specific network dysfunctions. The present study used functional magnetic resonance imaging (fMRI) to examine low-frequency (0.008?brain networks in older adults who participated in a 1-year intervention trial, comparing the effects of aerobic and non-aerobic fitness training on brain function and cognition. Results showed that aerobic training improved the aging brain's resting functional efficiency in higher-level cognitive networks. One year of walking increased functional connectivity between aspects of the frontal, posterior, and temporal cortices within the Default Mode Network and a Frontal Executive Network, two brain networks central to brain dysfunction in aging. Length of training was also an important factor. Effects in favor of the walking group were observed only after 12 months of training, compared to non-significant trends after 6 months. A non-aerobic stretching and toning group also showed increased functional connectivity in the DMN after 6 months and in a Frontal Parietal Network after 12 months, possibly reflecting experience-dependent plasticity. Finally, we found that changes in functional connectivity were behaviorally relevant. Increased functional connectivity was associated with greater improvement in executive function. Therefore the study provides the first evidence for exercise-induced functional plasticity in large-scale brain systems in the aging brain, using functional connectivity techniques, and offers new insight into the role of aerobic fitness in attenuating age-related brain dysfunction.

Voss, Michelle W.; Prakash, Ruchika S.; Erickson, Kirk I.; Basak, Chandramallika; Chaddock, Laura; Kim, Jennifer S.; Alves, Heloisa; Heo, Susie; Szabo, Amanda N.; White, Siobhan M.; Wojcicki, Thomas R.; Mailey, Emily L.; Gothe, Neha; Olson, Erin A.; McAuley, Edward; Kramer, Arthur F.

2010-01-01

102

Environmental Influences on Cognitive and Brain Plasticity During Aging  

Microsoft Academic Search

In the current article, we provide a critical review of the extant literature that has focused on environmental influences on cognitive and brain plasticity over the adult life span. The review includes both human epidemiological, and human and nonhuman cross-sectional and longitudinal research. We review a number of factors that have been suggested to reduce age-related cognitive decline including both

Arthur F. Kramer; Louis Bherer; Willie Dong; William T. Greenough

2004-01-01

103

Evolutionary perspectives on language and brain plasticity  

Microsoft Academic Search

Our understanding of speech and language disorders may be aided by information about the constraints and predispositions contributed by neural developmental processes. As soon as we begin to look at human neuroanatomy and development from a comparative perspective, it is possible to recognize a number of ways that human brains diverge from the general pattern of other ape and monkey

Terrence W Deacon

2000-01-01

104

Remodeling the Brain Plastic Structural Brain Changes Produced by Different Motor Therapies After Stroke  

PubMed Central

Background and Purpose Studies on adult stroke patients have demonstrated functional changes in cortical excitability, metabolic rate, or blood flow after motor therapy, measures that can fluctuate rapidly over time. This study evaluated whether evidence could also be found for structural brain changes during an efficacious rehabilitation program. Methods Chronic stroke patients were randomly assigned to receive either constraint-induced movement therapy (n=16) or a comparison therapy (n=20). Longitudinal voxel-based morphometry was performed on structural MRI scans obtained immediately before and after patients received therapy. Results The group receiving constraint-induced movement therapy exhibited far greater improvement in use of the more affected arm in the life situation than the comparison therapy group. Structural brain changes paralleled these improvements in spontaneous use of the more impaired arm for activities of daily living. There were profuse increases in gray matter in sensory and motor areas both contralateral and ipsilateral to the affected arm that were bilaterally symmetrical, as well as bilaterally in the hippocampus. In contrast, the comparison therapy group failed to show gray matter increases. Importantly, the magnitude of the observed gray matter increases was significantly correlated with amount of improvement in real-world arm use. Conclusions These findings suggest that a previously overlooked type of brain plasticity, structural remodeling of the human brain, is harnessed by constraint-induced movement therapy for a condition once thought to be refractory to treatment: motor deficit in chronic stroke patients.

Gauthier, Lynne V.; Taub, Edward; Perkins, Christi; Ortmann, Magdalene; Mark, Victor W.; Uswatte, Gitendra

2008-01-01

105

Phytoestrogens: hormonal action and brain plasticity  

Microsoft Academic Search

Because of their protective effects in age-related diseases and hormone-dependent cancers, the use of phytoestrogens (isoflavones) as ‘natural’ remedies has gained prominence. Isoflavones are estrogen mimics that bind estrogen receptors and act like natural selective estrogen receptors modulators. However, limited data exists regarding the influence of soy-derived dietary isoflavones in brain. This brief review will address these topics and examine

Edwin D. Lephart; Kenneth D. R. Setchell; Trent D. Lund

2005-01-01

106

Phytoestrogens: hormonal action and brain plasticity.  

PubMed

Because of their protective effects in age-related diseases and hormone-dependent cancers, the use of phytoestrogens (isoflavones) as 'natural' remedies has gained prominence. Isoflavones are estrogen mimics that bind estrogen receptors and act like natural selective estrogen receptors modulators. However, limited data exists regarding the influence of soy-derived dietary isoflavones in brain. This brief review will address these topics and examine the influence of dietary isoflavones on sexually dimorphic hypothalamic nuclei. We have observed that altering the isoflavone content within diet significantly affects both the sexually dimorphic nucleus of the preoptic area (a structure that is larger in males than in females) and the anteroventral periventricular nucleus (a structure that is larger in females than in males). Specifically, when animals were switched from phytoestrogen-rich to a phytoestrogen-free diet the volume of the sexually dimorphic nucleus of the preoptic area was decreased in males (no alterations were detected in females). Conversely, when the anteroventral periventricular nucleus was examined, volume changes were recorded in males and females opposite to the patterns observed for the sexually dimorphic nucleus of the preoptic area. Given the practical limitations of examining the effects of dietary phytoestrogens in the human brain, it is important to establish comparative data sets to elucidate phytoestrogen's hormone action and potentially its beneficial brain health effects. PMID:15811581

Lephart, Edwin D; Setchell, Kenneth D R; Lund, Trent D

2004-12-29

107

[Dehydroepiandrosterone and brain functioning].  

PubMed

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

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

2005-01-01

108

Experience-Dependent Neural Plasticity in the Adult Damaged Brain  

ERIC Educational Resources Information Center

|Behavioral experience is at work modifying the structure and function of the brain throughout the lifespan, but it has a particularly dramatic influence after brain injury. This review summarizes recent findings on the role of experience in reorganizing the adult damaged brain, with a focus on findings from rodent stroke models of chronic upper…

Kerr, Abigail L.; Cheng, Shao-Ying; Jones, Theresa A.

2011-01-01

109

Brain Deletion of Insulin Receptor Substrate 2 Disrupts Hippocampal Synaptic Plasticity and Metaplasticity  

PubMed Central

Objective Diabetes mellitus is associated with cognitive deficits and an increased risk of dementia, particularly in the elderly. These deficits and the corresponding neurophysiological structural and functional alterations are linked to both metabolic and vascular changes, related to chronic hyperglycaemia, but probably also defects in insulin action in the brain. To elucidate the specific role of brain insulin signalling in neuronal functions that are relevant for cognitive processes we have investigated the behaviour of neurons and synaptic plasticity in the hippocampus of mice lacking the insulin receptor substrate protein 2 (IRS-2). Research Design and Methods To study neuronal function and synaptic plasticity in the absence of confounding factors such as hyperglycaemia, we used a mouse model with a central nervous system- (CNS)-restricted deletion of IRS-2 (NesCreIrs2KO). Results We report a deficit in NMDA receptor-dependent synaptic plasticity in the hippocampus of NesCreIrs2KO mice, with a concomitant loss of metaplasticity, the modulation of synaptic plasticity by the previous activity of a synapse. These plasticity changes are associated with reduced basal phosphorylation of the NMDA receptor subunit NR1 and of downstream targets of the PI3K pathway, the protein kinases Akt and GSK-3?. Conclusions These findings reveal molecular and cellular mechanisms that might underlie cognitive deficits linked to specific defects of neuronal insulin signalling.

Costello, Derek A.; Claret, Marc; Al-Qassab, Hind; Plattner, Florian; Irvine, Elaine E.; Choudhury, Agharul I.; Giese, K. Peter; Withers, Dominic J.; Pedarzani, Paola

2012-01-01

110

Extremes of lineage plasticity in the Drosophila brain.  

PubMed

An often-overlooked aspect of neural plasticity is the plasticity of neuronal composition, in which the numbers of neurons of particular classes are altered in response to environment and experience. The Drosophila brain features several well-characterized lineages in which a single neuroblast gives rise to multiple neuronal classes in a stereotyped sequence during development [1]. We find that in the intrinsic mushroom body neuron lineage, the numbers for each class are highly plastic, depending on the timing of temporal fate transitions and the rate of neuroblast proliferation. For example, mushroom body neuroblast cycling can continue under starvation conditions, uncoupled from temporal fate transitions that depend on extrinsic cues reflecting organismal growth and development. In contrast, the proliferation rates of antennal lobe lineages are closely associated with organismal development, and their temporal fate changes appear to be cell cycle-dependent, such that the same numbers and types of uniglomerular projection neurons innervate the antennal lobe following various perturbations. We propose that this surprising difference in plasticity for these brain lineages is adaptive, given their respective roles as parallel processors versus discrete carriers of olfactory information. PMID:24055154

Lin, Suewei; Marin, Elizabeth C; Yang, Ching-Po; Kao, Chih-Fei; Apenteng, Bettye A; Huang, Yaling; O'Connor, Michael B; Truman, James W; Lee, Tzumin

2013-09-19

111

Self-Organized Criticality Model for Brain Plasticity  

Microsoft Academic Search

Networks of living neurons exhibit an avalanche mode of activity,\\u000aexperimentally found in organotypic cultures. Here we present a model based on\\u000aself-organized criticality and taking into account brain plasticity, which is\\u000aable to reproduce the spectrum of electroencephalograms (EEG). The model\\u000aconsists in an electrical network with threshold firing and activity-dependent\\u000asynapse strenghts. The system exhibits an avalanche activity

Lucilla de Arcangelis; Carla Perrone-Capano; Hans J. Herrmann

2006-01-01

112

Plasticity in neurological disorders and challenges for noninvasive brain stimulation (NBS)  

PubMed Central

There has been considerable interest in trialing NBS in a range of neurological conditions, and in parallel the range of NBS techniques available continues to expand. Underpinning this is the idea that NBS modulates neuroplasticity and that plasticity is an important contributor to functional recovery after brain injury and to the pathophysiology of neurological disorders. However while the evidence for neuroplasticity and its varied mechanisms is strong, the relationship to functional outcome is less clear and the clinical indications remain to be determined. To be maximally effective, the application of NBS techniques will need to be refined to take into account the diversity of neurological symptoms, the fundamental differences between acute, longstanding and chronic progressive disease processes, and the differential part played by functional and dysfunctional plasticity in diseases of the brain and spinal cord.

Thickbroom, Gary W; Mastaglia, Frank L

2009-01-01

113

Using non-invasive brain stimulation to augment motor training-induced plasticity  

PubMed Central

Therapies for motor recovery after stroke or traumatic brain injury are still not satisfactory. To date the best approach seems to be the intensive physical therapy. However the results are limited and functional gains are often minimal. The goal of motor training is to minimize functional disability and optimize functional motor recovery. This is thought to be achieved by modulation of plastic changes in the brain. Therefore, adjunct interventions that can augment the response of the motor system to the behavioural training might be useful to enhance the therapy-induced recovery in neurological populations. In this context, noninvasive brain stimulation appears to be an interesting option as an add-on intervention to standard physical therapies. Two non-invasive methods of inducing electrical currents into the brain have proved to be promising for inducing long-lasting plastic changes in motor systems: transcranial magnetic stimulation (TMS) and transcranial direct current stimulation (tDCS). These techniques represent powerful methods for priming cortical excitability for a subsequent motor task, demand, or stimulation. Thus, their mutual use can optimize the plastic changes induced by motor practice, leading to more remarkable and outlasting clinical gains in rehabilitation. In this review we discuss how these techniques can enhance the effects of a behavioural intervention and the clinical evidence to date.

Bolognini, Nadia; Pascual-Leone, Alvaro; Fregni, Felipe

2009-01-01

114

The insular lobe and brain plasticity: Lessons from tumor surgery  

Microsoft Academic Search

ObjectivesDespite recent literature supporting the likely role of the insula in many functions, the actual participation of this multimodal lobe in the brain functioning remains unclear, i.e. has the insula an essential or compensable role?

Hugues Duffau; Luc Taillandier; Peggy Gatignol; Laurent Capelle

2006-01-01

115

MRI in small brains displaying extensive plasticity  

Microsoft Academic Search

Manganese-enhanced magnetic resonance imaging (ME-MRI), blood oxygen-level-dependent functional MRI (BOLD fMRI) and diffusion tensor imaging (DTI) can now be applied to animal species as small as mice or songbirds. These techniques confirmed previous find- ings but are also beginning to reveal new phenomena that were difficult or impossible to study previously. These imaging techniques will lead to major technical and

Annemie Van der Linden; Vincent Van Meir; Tiny Boumans; Colline Poirier; Jacques Balthazart

2009-01-01

116

Structural plasticity upon learning: regulation and functions.  

PubMed

Recent studies have provided long-sought evidence that behavioural learning involves specific synapse gain and elimination processes, which lead to memory traces that influence behaviour. The connectivity rearrangements are preceded by enhanced synapse turnover, which can be modulated through changes in inhibitory connectivity. Behaviourally related synapse rearrangement events tend to co-occur spatially within short stretches of dendrites, and involve signalling pathways partially overlapping with those controlling the functional plasticity of synapses. The new findings suggest that a mechanistic understanding of learning and memory processes will require monitoring ensembles of synapses in situ and the development of synaptic network models that combine changes in synaptic function and connectivity. PMID:22714019

Caroni, Pico; Donato, Flavio; Muller, Dominique

2012-06-20

117

Characterizing Brain Cortical Plasticity and Network Dynamics Across the Age-Span in Health and Disease with TMS-EEG and TMS-fMRI  

Microsoft Academic Search

Brain plasticity can be conceptualized as nature’s invention to overcome limitations of the genome and adapt to a rapidly\\u000a changing environment. As such, plasticity is an intrinsic property of the brain across the lifespan. However, mechanisms of\\u000a plasticity may vary with age. The combination of transcranial magnetic stimulation (TMS) with electroencephalography (EEG)\\u000a or functional magnetic resonance imaging (fMRI) enables clinicians

Alvaro Pascual-Leone; Catarina Freitas; Lindsay Oberman; Jared C. Horvath; Mark Halko; Mark Eldaief; Shahid Bashir; Marine Vernet; Mouhshin Shafi; Brandon Westover; Andrew M. Vahabzadeh-Hagh; Alexander Rotenberg

118

Aromatase, brain sexualization and plasticity: the fish paradigm.  

PubMed

In contrast to mammals, teleost fish have a very labile genetic sex determination. Sex differentiation is influenced by a combination of hormonal, social and environmental factors and teleost fishes exhibit many examples of hermaphroditism. This means that the brain of fish is not irreversibly sexualized early in life. This review aims at highlighting some unique features of fish that may explain their brain sexual plasticity. Unlike mammals, in which brain aromatase activity decreases after birth, adult teleosts exhibit an intense aromatase activity due to strong expression of one of two aromatase genes (aromatase A or cyp19a1a and aromatase B or cyp19a1b) that arose from a gene duplication event. Interestingly, aromatase B is only expressed in radial glial cells (RGC) of adult fish. These cells persist throughout life and act as progenitors in the brain of both developing and adult fish. In agreement with the fact that brain aromatase activity is correlated with sex steroid levels, the high expression of cyp19a1b is due to an autoregulatory loop through which estrogens and aromatizable androgens upregulate aromatase expression. Given the well-established roles of estrogens and aromatase on brain sexualization, these features suggest that the brain of fish conserves properties of embryonic mammalian brain throughout life - high neurogenic activity and high aromatase expression in progenitor cells correlated with sex steroid levels. The permanent dialogue between the brain and the gonad would permit sex changes and thus the emergence of a variety of reproductive strategies. Other hypotheses are also discussed. PMID:21143665

Le Page, Yann; Diotel, Nicolas; Vaillant, Colette; Pellegrini, Elisabeth; Anglade, Isabelle; Mérot, Yohann; Kah, Olivier

2010-12-01

119

Increased morphological asymmetry, evolvability and plasticity in human brain evolution.  

PubMed

The study of hominin brain evolution relies mostly on evaluation of the endocranial morphology of fossil skulls. However, only some general features of external brain morphology are evident from endocasts, and many anatomical details can be difficult or impossible to examine. In this study, we use geometric morphometric techniques to evaluate inter- and intraspecific differences in cerebral morphology in a sample of in vivo magnetic resonance imaging scans of chimpanzees and humans, with special emphasis on the study of asymmetric variation. Our study reveals that chimpanzee-human differences in cerebral morphology are mainly symmetric; by contrast, there is continuity in asymmetric variation between species, with humans showing an increased range of variation. Moreover, asymmetric variation does not appear to be the result of allometric scaling at intraspecific levels, whereas symmetric changes exhibit very slight allometric effects within each species. Our results emphasize two key properties of brain evolution in the hominine clade: first, evolution of chimpanzee and human brains (and probably their last common ancestor and related species) is not strongly morphologically constrained, thus making their brains highly evolvable and responsive to selective pressures; second, chimpanzee and, especially, human brains show high levels of fluctuating asymmetry indicative of pronounced developmental plasticity. We infer that these two characteristics can have a role in human cognitive evolution. PMID:23615289

Gómez-Robles, Aida; Hopkins, William D; Sherwood, Chet C

2013-04-24

120

Extracellular matrix inhibits structural and functional plasticity of dendritic spines in the adult visual cortex.  

PubMed

Brain cells are immersed in a complex structure forming the extracellular matrix. The composition of the matrix gradually matures during postnatal development, as the brain circuitry reaches its adult form. The fully developed extracellular environment stabilizes neuronal connectivity and decreases cortical plasticity as highlighted by the demonstration that treatments degrading the matrix are able to restore synaptic plasticity in the adult brain. The mechanisms through which the matrix inhibits cortical plasticity are not fully clarified. Here we show that a prominent component of the matrix, chondroitin sulfate proteoglycans (CSPGs), restrains morphological changes of dendritic spines in the visual cortex of adult mice. By means of in vivo and in vitro two-photon imaging and electrophysiology, we find that after enzymatic digestion of CSPGs, cortical spines become more motile and express a larger degree of structural and functional plasticity. PMID:23403561

de Vivo, L; Landi, S; Panniello, M; Baroncelli, L; Chierzi, S; Mariotti, L; Spolidoro, M; Pizzorusso, T; Maffei, L; Ratto, G M

2013-01-01

121

Pain and the brain: Specificity and plasticity of the brain in clinical chronic pain  

PubMed Central

We review recent advances in brain imaging in humans, concentrating on advances in our understanding of the human brain in clinical chronic pain. Understanding regarding anatomical and functional reorganization of the brain in chronic pain is emphasized. We conclude by proposing a brain model for the transition of the human from acute to chronic pain.

Apkarian, A.V.; Hashmi, J.A.; Baliki, M.N.

2010-01-01

122

Late human brain plasticity: vestibular substitution with a tongue BrainPorthuman -machine interface  

Microsoft Academic Search

ABSTRACT. The brain is capable of major reorganization even many,years after an injury, with appropriate rehabilitation. The highly plastic brain responds best when the therapy is motivating and has a benefit that is recognized by the patient. The major objective of this study was to estimate feasibility and efficacy of an electro-tactile vestibular substitution system,(ETVSS)in aiding recovery of posture control

Paul Bach-y-rita; Yuri Danilov; Mitchell E. Tylersup?; Robert J. Grimm

123

Review of Research: Neuroscience and the Impact of Brain Plasticity on Braille Reading  

ERIC Educational Resources Information Center

|In this systematic review of research, the author analyzes studies of neural cortical activation, brain plasticity, and braille reading. The conclusions regarding the brain's plasticity and ability to reorganize are encouraging for individuals with degenerative eye conditions or late-onset blindness because they indicate that the brain can make…

Hannan, Cheryl Kamei

2006-01-01

124

Functional site plasticity in domain superfamilies?  

PubMed Central

We present, to our knowledge, the first quantitative analysis of functional site diversity in homologous domain superfamilies. Different types of functional sites are considered separately. Our results show that most diverse superfamilies are very plastic in terms of the spatial location of their functional sites. This is especially true for protein–protein interfaces. In contrast, we confirm that catalytic sites typically occupy only a very small number of topological locations. Small-ligand binding sites are more diverse than expected, although in a more limited manner than protein–protein interfaces. In spite of the observed diversity, our results also confirm the previously reported preferential location of functional sites. We identify a subset of homologous domain superfamilies where diversity is particularly extreme, and discuss possible reasons for such plasticity, i.e. structural diversity. Our results do not contradict previous reports of preferential co-location of sites among homologues, but rather point at the importance of not ignoring other sites, especially in large and diverse superfamilies. Data on sites exploited by different relatives, within each well annotated domain superfamily, has been made accessible from the CATH website in order to highlight versatile superfamilies or superfamilies with highly preferential sites. This information is valuable for system biology and knowledge of any constraints on protein interactions could help in understanding the dynamic control of networks in which these proteins participate. The novelty of our work lies in the comprehensive nature of the analysis – we have used a significantly larger dataset than previous studies – and the fact that in many superfamilies we show that different parts of the domain surface are exploited by different relatives for ligand/protein interactions, particularly in superfamilies which are diverse in sequence and structure, an observation not previously reported on such a large scale. This article is part of a Special Issue entitled: The emerging dynamic view of proteins: Protein plasticity in allostery, evolution and self-assembly.

Dessailly, Benoit H.; Dawson, Natalie L.; Mizuguchi, Kenji; Orengo, Christine A.

2013-01-01

125

Plasticity of cortical maps: multiple triggers for adaptive reorganization following brain damage and spinal cord injury.  

PubMed

Sensory and motor representations embedded in topographic cortical maps are use-dependent, dynamically maintained, and self-organizing functional mosaics that constitute idiosyncratic entities involved in perceptual and motor learning abilities. Studies of cortical map plasticity have substantiated the view that local reorganization of sensory and motor areas has great significance in recovery of function following brain damage or spinal cord injury. In addition, the transfer of function to distributed cortical areas and subcortical structures represents an adaptive strategy for functional compensation. There is a growing consensus that subject-environment interactions, by continuously refining the canvas of synaptic connectivity and reshaping the anatomical and functional architecture of neural circuits, promote adaptive behavior throughout life. Taking advantage of use-dependent neural plasticity, early initiated rehabilitative procedures improve the potential for recovery. PMID:21636850

Xerri, Christian

2011-06-02

126

Structural brain plasticity in Parkinson's disease induced by balance training.  

PubMed

We investigated morphometric brain changes in patients with Parkinson's disease (PD) that are associated with balance training. A total of 20 patients and 16 healthy matched controls learned a balance task over a period of 6 weeks. Balance testing and structural magnetic resonance imaging were performed before and after 2, 4, and 6 training weeks. Balance performance was re-evaluated after ?20 months. Balance training resulted in performance improvements in both groups. Voxel-based morphometry revealed learning-dependent gray matter changes in the left hippocampus in healthy controls. In PD patients, performance improvements were correlated with gray matter changes in the right anterior precuneus, left inferior parietal cortex, left ventral premotor cortex, bilateral anterior cingulate cortex, and left middle temporal gyrus. Furthermore, a TIME × GROUP interaction analysis revealed time-dependent gray matter changes in the right cerebellum. Our results highlight training-induced balance improvements in PD patients that may be associated with specific patterns of structural brain plasticity. In summary, we provide novel evidence for the capacity of the human brain to undergo learning-related structural plasticity even in a pathophysiological disease state such as in PD. PMID:23916062

Sehm, Bernhard; Taubert, Marco; Conde, Virginia; Weise, David; Classen, Joseph; Dukart, Juergen; Draganski, Bogdan; Villringer, Arno; Ragert, Patrick

2013-08-01

127

Function-Dependent Plasticity in the Nervous System.  

National Technical Information Service (NTIS)

The tectum opticum of fish midbrain is studied to demonstrate the involvement of gangliosides in the functional plastic changes in synaptic systems and in visual acuity. The structural synaptic plasticity after light variations involving synaptic vesicles...

H. Rahmann W. Probst

1987-01-01

128

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

129

Vascular changes and brain plasticity: a new approach to neurodegenerative diseases  

PubMed Central

The world’s population is aging, which will result in an increasing prevalence of neurodegenerative diseases, such as dementia. Observations from functional brain imaging that older brains can be more active than their younger counterparts challenge stereotypical ideas of aging. In those aging successfully, brain activation is more anterior, less lateralized and more coordinated than in those at risk of, or suffering from, cognitive impairment. Several theories have been proposed to explain these findings. One of the most enticing is the scaffolding theory, which posits that the older brain is a plastic homeostatic organ, able to compensate for its deteriorating structure. However, with aging also come diffuse vascular changes and the resulting white matter damage. This decreases the compensatory capacity, and dementia can ensue. This and alternative hypotheses will be discussed, along with potential methodological problems of this genre of study and with their clinical implications.

Topiwala, Anya; Ebmeier, Klaus P

2012-01-01

130

Vascular changes and brain plasticity: a new approach to neurodegenerative diseases.  

PubMed

The world's population is aging, which will result in an increasing prevalence of neurodegenerative diseases, such as dementia. Observations from functional brain imaging that older brains can be more active than their younger counterparts challenge stereotypical ideas of aging. In those aging successfully, brain activation is more anterior, less lateralized and more coordinated than in those at risk of, or suffering from, cognitive impairment. Several theories have been proposed to explain these findings. One of the most enticing is the scaffolding theory, which posits that the older brain is a plastic homeostatic organ, able to compensate for its deteriorating structure. However, with aging also come diffuse vascular changes and the resulting white matter damage. This decreases the compensatory capacity, and dementia can ensue. This and alternative hypotheses will be discussed, along with potential methodological problems of this genre of study and with their clinical implications. PMID:23383389

Topiwala, Anya; Ebmeier, Klaus P

2012-07-23

131

Paired pulse ratio analysis of insulin-induced synaptic plasticity in the snail brain.  

PubMed

Insulin's action in the brain can directly alter cognitive functioning. We have recently shown that molluscan insulin-related peptides are upregulated following a conditioned taste aversion (CTA) training procedure. In addition, when mammalian insulin is superfused over the isolated Lymnaea stagnalis central nervous system, it elicits long-term synaptic enhancement at the monosynaptic connection between the cerebral giant cell and the buccal 1 (B1) motor neuron. This synaptic enhancement is thought to be a neural correlate of CTA. Here, we examined whether the observed changes in synaptic plasticity were the result of presynaptic and/or postsynaptic alterations using the paired pulse procedure. The paired pulse ratio was unaltered following insulin application, suggesting that insulin's effects on synaptic plasticity are mediated postsynaptically in the B1 motor neuron. Thus, it was suggested that postsynaptic changes need to be considered when insulin's actions on synaptic plasticity are examined. PMID:23393274

Murakami, Jun; Okada, Ryuichi; Fujito, Yutaka; Sakakibara, Manabu; Lukowiak, Ken; Ito, Etsuro

2013-02-07

132

Memory enhancement in healthy older adults using a brain plasticity-based training program: A randomized, controlled study  

Microsoft Academic Search

Normal aging is associated with progressive functional losses in perception, cognition, and memory. Although the root causes of age-related cognitive decline are incompletely understood, psychophysical and neuropsychological evidence suggests that a significant contribution stems from poorer signal-to-noise conditions and down-regulated neuromodulatory system function in older brains. Because the brain retains a lifelong capacity for plasticity and adaptive reorganization, dimensions of

Henry W. Mahncke; Bonnie B. Connor; Jed Appelman; Omar N. Ahsanuddin; Joseph L. Hardy; Richard A. Wood; Nicholas M. Joyce; Tania Boniske; Sharona M. Atkins; Michael M. Merzenich

2006-01-01

133

Self-Organized Criticality Model for Brain Plasticity  

NASA Astrophysics Data System (ADS)

Networks of living neurons exhibit an avalanche mode of activity, experimentally found in organotypic cultures. Here we present a model that is based on self-organized criticality and takes into account brain plasticity, which is able to reproduce the spectrum of electroencephalograms (EEG). The model consists of an electrical network with threshold firing and activity-dependent synapse strengths. The system exhibits an avalanche activity in a power-law distribution. The analysis of the power spectra of the electrical signal reproduces very robustly the power-law behavior with the exponent 0.8, experimentally measured in EEG spectra. The same value of the exponent is found on small-world lattices and for leaky neurons, indicating that universality holds for a wide class of brain models.

de Arcangelis, Lucilla; Perrone-Capano, Carla; Herrmann, Hans J.

2006-01-01

134

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

135

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

PubMed Central

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

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

2011-01-01

136

Interactions between environmental changes and brain plasticity in birds.  

PubMed

Neurogenesis and neuronal recruitment occur in many vertebrates, including humans. Most of the new neurons die before reaching their destination. Those which survive migrate to various brain regions, replace older ones and connect to existing circuits. Evidence suggests that this replacement is related to acquisition of new information. Therefore, neuronal replacement can be seen as a form of brain plasticity that enables organisms to adjust to environmental changes. However, direct evidence of a causal link between replacement and learning remains elusive. Our hypothesis is that increased neuronal recruitment is associated with increase in memory load. Moreover, since neuronal recruitment is part of a turnover process, we assume that the same conditions that favor survival of some neurons induce the death of others. I present studies that investigated the effect of various behaviors and environmental conditions (food-hoarding, social change, reproductive cycle) on neuronal recruitment and survival in adult avian brains, and discuss how these phenomena relate to the life of animals. I offer a frame and rationale for comparing neuronal replacement in the adult brain, in order to uncover the pressures, rules, and mechanisms that govern its constant rejuvenation. The review emphasizes the importance of using various approaches (behavioral, anatomical, cellular and hormonal) in neuroethological research, and the need to study natural populations, in order to fully understand how neurogenesis and neuronal replacement contribute to life of animals. Finally, the review indicates to future directions and ends with the hope that a better understanding of adult neuronal replacement will lead to medical applications. PMID:19361509

Barnea, Anat

2009-04-08

137

Bridging animal and human models of exercise-induced brain plasticity.  

PubMed

Significant progress has been made in understanding the neurobiological mechanisms through which exercise protects and restores the brain. In this feature review, we integrate animal and human research, examining physical activity effects across multiple levels of description (neurons up to inter-regional pathways). We evaluate the influence of exercise on hippocampal structure and function, addressing common themes such as spatial memory and pattern separation, brain structure and plasticity, neurotrophic factors, and vasculature. Areas of research focused more within species, such as hippocampal neurogenesis in rodents, also provide crucial insight into the protective role of physical activity. Overall, converging evidence suggests exercise benefits brain function and cognition across the mammalian lifespan, which may translate into reduced risk for Alzheimer's disease (AD) in humans. PMID:24029446

Voss, Michelle W; Vivar, Carmen; Kramer, Arthur F; van Praag, Henriette

2013-09-09

138

Adult neurogenesis and functional plasticity in neuronal circuits  

Microsoft Academic Search

The adult brain is a plastic place. To ensure that the mature nervous system's control of behaviour is flexible in the face of a varying environment, morphological and physiological changes are possible at many levels, including that of the entire cell. In two areas of the adult brain — the olfactory bulb and the dentate gyrus — new neurons are

Mariana Alonso; Matthew S. Grubb; Pierre-Marie Lledo

2006-01-01

139

Chondroitin sulphate proteoglycans: key modulators of spinal cord and brain plasticity.  

PubMed

Chondroitin sulphate proteoglycans (CSPGs) are a family of inhibitory extracellular matrix molecules that are highly expressed during development, where they are involved in processes of pathfinding and guidance. CSPGs are present at lower levels in the mature CNS, but are highly concentrated in perineuronal nets where they play an important role in maintaining stability and restricting plasticity. Whilst important for maintaining stable connections, this can have an adverse effect following insult to the CNS, restricting the capacity for repair, where enhanced synapse formation leading to new connections could be functionally beneficial. CSPGs are also highly expressed at CNS injury sites, where they can restrict anatomical plasticity by inhibiting sprouting and reorganisation, curbing the extent to which spared systems may compensate for the loss function of injured pathways. Modification of CSPGs, usually involving enzymatic degradation of glycosaminoglycan chains from the CSPG molecule, has received much attention as a potential strategy for promoting repair following spinal cord and brain injury. Pre-clinical studies in animal models have demonstrated a number of reparative effects of CSPG modification, which are often associated with functional recovery. Here we discuss the potential of CSPG modification to stimulate restorative plasticity after injury, reviewing evidence from studies in the brain, the spinal cord and the periphery. PMID:21871887

Bartus, K; James, N D; Bosch, K D; Bradbury, E J

2011-08-16

140

Length of Acupuncture Training and Structural Plastic Brain Changes in Professional Acupuncturists  

PubMed Central

Background The research on brain plasticity has fascinated researchers for decades. Use/training serves as an instrumental factor to influence brain neuroplasticity. Parallel to acquisition of behavioral expertise, extensive use/training is concomitant with substantial changes of cortical structure. Acupuncturists, serving as a model par excellence to study tactile-motor and emotional regulation plasticity, receive intensive training in national medical schools following standardized training protocol. Moreover, their behavioral expertise is corroborated during long-term clinical practice. Although our previous study reported functional plastic brain changes in the acupuncturists, whether or not structural plastic changes occurred in acupuncturists is yet elusive. Methodology/Principal Findings Cohorts of acupuncturists (N?=?22) and non-acupuncturists (N?=?22) were recruited. Behavioral tests were delivered to assess the acupuncturists’ behavioral expertise. The results confirmed acupuncturists’ tactile-motor skills and emotion regulation proficiency compared to non-acupuncturists. Using the voxel-based morphometry technique, we revealed larger grey matter volumes in acupuncturists in the hand representation of the contralateral primary somatosensory cortex (SI), the right lobule V/VI and the bilateral ventral anterior cingulate cortex/ventral medial prefrontal cortex. Grey matter volumes of the SI and Lobule V/VI positively correlated with the duration of acupuncture practice. Conclusions To our best knowledge, this study provides first evidence for the anatomical alterations in acupuncturists, which would possibly be the neural correlates underlying acupuncturists’ exceptional skills. On one hand, we suggest our findings may have ramifications for tactile-motor rehabilitation. On the other hand, our results in emotion regulation domain may serve as a target for our future studies, from which we can understand how modulations of aversive emotions elicited by empathic pain develop in the context of expertise. Future longitudinal study is necessary to establish the presence and direction of a causal link between practice/use and brain anatomy.

Dong, Minghao; Zhao, Ling; Yuan, Kai; Zeng, Fang; Sun, Jinbo; Liu, Jixin; Yu, Dahua; von Deneen, Karen M.; Liang, Fanrong; Qin, Wei; Tian, Jie

2013-01-01

141

Alteration and reorganization of functional networks: a new perspective in brain injury study.  

PubMed

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

Castellanos, Nazareth P; Bajo, Ricardo; Cuesta, Pablo; Villacorta-Atienza, José Antonio; Paúl, Nuria; Garcia-Prieto, Juan; Del-Pozo, Francisco; Maestú, Fernando

2011-09-21

142

Functional brain mapping of psychopathology  

PubMed Central

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

Honey, G; Fletcher, P; Bullmore, E

2002-01-01

143

Estrogen-induced plasticity from cells to circuits: predictions for cognitive function  

PubMed Central

Controversy regarding estrogen action in the brain remains at the forefront of basic, translational and clinical science for women’s health. Here, I provide an integrative analysis of estrogen-inducible plasticity and posit it as a strategy for predicting cognitive domains affected by estrogen in addition to sources of variability. Estrogen enhancement of plasticity is evidenced by increases in neurogenesis, neural network connectivity and synaptic transmission. In parallel, estrogen increases glucose transport, aerobic glycolysis and mitochondrial function to provide the ATP necessary to sustain increased energetic demand. The pattern of plasticity predicts that estrogen would preferentially affect cognitive tasks of greater complexity, temporal demand and associative challenge. Thus, estrogen deprivation should be associated with decrements in these functions. Estrogen regulation of plasticity and bioenergetics provides a framework for predicting estrogen-dependent cognitive functions while also identifying sources of variability and potential biomarkers for identifying women appropriate for hormone therapy.

Brinton, Roberta Diaz

2011-01-01

144

Molecular mechanisms that underlie structural and functional changes atthe postsynaptic membrane duringsynaptic plasticity  

Microsoft Academic Search

The synaptic plasticity that is addressed in this review follows neurodegeneration in the brain and thus has both structural as well as functional components. The model of neurodegeneration that has been selected is the kainic acid lesioned hippocampus. Degeneration of the CA3 pyramidal cells results in a loss of the Schaffer collateral afferents innervating the CA1 pyramidal cells. This is

Howard V Wheal; Ying Chen; John Mitchell; Melitta Schachner; Winfried Maerz; Heinrich Wieland; Denise van Rossum; Joachim Kirsch

1998-01-01

145

Musical training influences linguistic abilities in 8-year-old children: more evidence for brain plasticity.  

PubMed

We conducted a longitudinal study with 32 nonmusician children over 9 months to determine 1) whether functional differences between musician and nonmusician children reflect specific predispositions for music or result from musical training and 2) whether musical training improves nonmusical brain functions such as reading and linguistic pitch processing. Event-related brain potentials were recorded while 8-year-old children performed tasks designed to test the hypothesis that musical training improves pitch processing not only in music but also in speech. Following the first testing sessions nonmusician children were pseudorandomly assigned to music or to painting training for 6 months and were tested again after training using the same tests. After musical (but not painting) training, children showed enhanced reading and pitch discrimination abilities in speech. Remarkably, 6 months of musical training thus suffices to significantly improve behavior and to influence the development of neural processes as reflected in specific pattern of brain waves. These results reveal positive transfer from music to speech and highlight the influence of musical training. Finally, they demonstrate brain plasticity in showing that relatively short periods of training have strong consequences on the functional organization of the children's brain. PMID:18832336

Moreno, Sylvain; Marques, Carlos; Santos, Andreia; Santos, Manuela; Castro, São Luís; Besson, Mireille

2008-10-01

146

Training the Brain: Practical Applications of Neural Plasticity From the Intersection of Cognitive Neuroscience, Developmental Psychology, and Prevention Science  

PubMed Central

Prior researchers have shown that the brain has a remarkable ability for adapting to environmental changes. The positive effects of such neural plasticity include enhanced functioning in specific cognitive domains and shifts in cortical representation following naturally occurring cases of sensory deprivation; however, maladaptive changes in brain function and development owing to early developmental adversity and stress have also been well documented. Researchers examining enriched rearing environments in animals have revealed the potential for inducing positive brain plasticity effects and have helped to popularize methods for training the brain to reverse early brain deficits or to boost normal cognitive functioning. In this paper, two classes of empirically based methods of brain training in children are reviewed and critiqued: laboratory-based, mental process training paradigms and ecological interventions based upon neurocognitive conceptual models. Given the susceptibility of executive function disruption, special attention is paid to training programs that emphasize executive function enhancement. In addition, a third approach to brain training, aimed at tapping into compensatory processes, is postulated. Study results showing the effectiveness of this strategy in the field of neurorehabilitation and in terms of naturally occurring compensatory processing in human aging lend credence to the potential of this approach.

Bryck, Richard L.; Fisher, Philip A.

2012-01-01

147

[Sleep and brain function].  

PubMed

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

Urade, Yoshihiro; Mohri, Ikuko

2006-09-01

148

Whole brain functional connectivity in the early blind.  

PubMed

Early visual deprivation can lead to changes in the brain, which may be explained by either of two hypotheses. The general loss hypothesis has been proposed to explain maladjustments, while the compensatory plasticity hypothesis may explain a superior ability in the use of the remaining senses. Most previous task-based functional MRI (fMRI) studies have supported the compensatory plasticity hypothesis, but it has been difficult to provide evidence to support the general loss hypothesis, since the blind cannot execute visual tasks. The study of resting state fMRI data may provide an opportunity to simultaneously detect the two aspects of changes in the blind. In this study, using a whole brain perspective, we investigated the decreased and increased functional connectivities in the early blind using resting state fMRI data. The altered functional connectivities were identified by comparing the correlation coefficients of each pair of brain regions of 16 early blind subjects (9 males; age range: 15.6-29.3 years, mean age: 22.1 years) with the corresponding coefficients of gender- and age-matched sighted volunteers. Compared with the sighted subjects, the blind demonstrated the decreased functional connectivities within the occipital visual cortices as well as between the occipital visual cortices and the parietal somatosensory, frontal motor and temporal multisensory cortices. Such differences may support the general loss hypothesis. However, we also found that the introduction of Braille earlier in life and for longer daily practice times produced stronger functional connectivities between these brain areas. These findings may support the compensatory plasticity hypothesis. Additionally, we found several increased functional connectivities between the occipital cortices and frontal language cortices in those with early onset of blindness, which indicate the predominance of compensatory plasticity. Our findings indicate that changes in the functional connectivities in the resting state may be an integrated reflection of general loss and compensatory plasticity when a single sensory modality is deprived. PMID:17533167

Liu, Yong; Yu, Chunshui; Liang, Meng; Li, Jun; Tian, Lixia; Zhou, Yuan; Qin, Wen; Li, Kuncheng; Jiang, Tianzi

2007-05-28

149

Exercise: a behavioral intervention to enhance brain health and plasticity  

Microsoft Academic Search

Extensive research on humans suggests that exercise could have benefits for overall health and cognitive function, particularly in later life. Recent studies using animal models have been directed towards understanding the neurobiological bases of these benefits. It is now clear that voluntary exercise can increase levels of brain-derived neurotrophic factor (BDNF) and other growth factors, stimulate neurogenesis, increase resistance to

Carl W. Cotman; Nicole C. Berchtold

2002-01-01

150

Intensive language training enhances brain plasticity in chronic aphasia  

Microsoft Academic Search

BACKGROUND: Focal clusters of slow wave activity in the delta frequency range (1–4 Hz), as measured by magnetencephalography (MEG), are usually located in the vicinity of structural damage in the brain. Such oscillations are usually considered pathological and indicative of areas incapable of normal functioning owing to deafferentation from relevant input sources. In the present study we investigated the change

Marcus Meinzer; Thomas Elbert; Christian Wienbruch; Daniela Djundja; Gabriela Barthel; Brigitte Rockstroh

2004-01-01

151

Training-induced behavioral and brain plasticity in inhibitory control.  

PubMed

Deficits in inhibitory control, the ability to suppress ongoing or planned motor or cognitive processes, contribute to many psychiatric and neurological disorders. The rehabilitation of inhibition-related disorders may therefore benefit from neuroplasticity-based training protocols aiming at normalizing inhibitory control proficiency and the underlying brain networks. Current literature on training-induced behavioral and brain plasticity in inhibitory control suggests that improvements may follow either from the development of automatic forms of inhibition or from the strengthening of top-down, controlled inhibition. Automatic inhibition develops in conditions of consistent and repeated associations between inhibition-triggering stimuli and stopping goals. Once established, the stop signals directly elicit inhibition, thereby bypassing slow, top-down executive control and accelerating stopping processes. In contrast, training regimens involving varying stimulus-response associations or frequent inhibition failures prevent the development of automatic inhibition and thus strengthen top-down inhibitory processes rather than bottom-up ones. We discuss these findings in terms of developing optimal inhibitory control training regimens for rehabilitation purposes. PMID:23914169

Spierer, Lucas; Chavan, Camille F; Manuel, Aurelie L

2013-08-01

152

Current trends in stroke rehabilitation. A review with focus on brain plasticity.  

PubMed

Current understanding of brain plasticity has lead to new approaches in ischemic stroke rehabilitation. Stroke units that combine good medical and nursing care with task-oriented intense training in an environment that provides confidence, stimulation and motivation significantly improve outcome. Repetitive trans-cranial magnetic stimulation (rTMS), and trans-cranial direct current stimulation (tDCS) are applied in rehabilitation of motor function. The long-term effect, optimal way of stimulation and possibly efficacy in cognitive rehabilitation need evaluation. Methods based on multisensory integration of motor, cognitive, and perceptual processes including action observation, mental training, and virtual reality are being tested. Different approaches of intensive aphasia training are described. Recent data on intensive melodic intonation therapy indicate that even patients with very severe non-fluent aphasia can regain speech through homotopic white matter tract plasticity. Music therapy is applied in motor and cognitive rehabilitation. To avoid the confounding effect of spontaneous improvement, most trials are preformed ?3 months post stroke. Randomized controlled trials starting earlier after strokes are needed. More attention should be given to stroke heterogeneity, cognitive rehabilitation, and social adjustment and to genetic differences, including the role of BDNF polymorphism in brain plasticity. PMID:20726844

Johansson, B B

2010-08-19

153

Brain organization and sleep function  

Microsoft Academic Search

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

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

1995-01-01

154

Plasticity of mouse brain docosahexaenoic acid: modulation by diet and age.  

PubMed

Decreases in brain docosahexaenoic acid (DHA) have been associated with losses in brain function leading to an interest in the conditions which lead to such brain decreases, and such variables as age. Also of relevance would be the rate of repletion of DHA when the n-3 dietary deficiency is reversed. This experiment describes dietary deficiency in n-3 fatty acids induced in weanling (3 week) and young adult (7 week) mice. There was an immediate and continuous loss of brain DHA with similar rates in the two age groups. Serum DHA declined more rapidly in younger animals with respect to similarly treated adults. Brain and serum docosapentaenoic acid (DPAn-6) increased more rapidly and to higher levels in the younger animals. A second experiment determined the rates of normalization of brain fatty acid profiles when alpha-linolenic acid was added to the diets of n-3 deficient mice. Brain DHA recovery occurred at a faster rate (half-time, T 1/2 = 1.4 weeks) when begun at weaning relative to young adult mice (T 1/2 = 3.5 weeks). Correspondingly, brain DPAn-6 recovered faster in the younger animals; the adult group had a half-time of more than twice that of the 3-week old group. This study therefore demonstrates that the young adult mouse brain DHA is somewhat plastic and can be partially depleted via a low n-3 fatty acid diet and subsequently restored when dietary n-3 fatty acids are repleted. Relevance of these findings for human nutrition is discussed. PMID:23460301

Moriguchi, Toru; Harauma, Akiko; Salem, Norman

2013-03-05

155

Emerging roles of non-coding RNAs in brain evolution, development, plasticity and disease  

PubMed Central

Novel classes of small and long non-coding RNAs (ncRNAs) are being characterized at a rapid pace, driven by recent paradigm shifts in our understanding of genomic architecture, regulation and transcriptional output, as well as by innovations in sequencing technologies and computational and systems biology. These ncRNAs can interact with DNA, RNA and protein molecules; engage in diverse structural, functional and regulatory activities; and have roles in nuclear organization and transcriptional, post-transcriptional and epigenetic processes. This expanding inventory of ncRNAs is implicated in mediating a broad spectrum of processes including brain evolution, development, synaptic plasticity and disease pathogenesis.

Qureshi, Irfan A.; Mehler, Mark F.

2012-01-01

156

Adaptive plasticity in motor cortex: implications for rehabilitation after brain injury.  

PubMed

It is now widely recognized that the cerebral cortex of adult human and non-human mammals is capable of widespread functional and structural plasticity. During the learning of new skills, cortical regions associated with sensorimotor function of the body parts most utilized for the skilled task come to be represented over larger cortical territories. More recent studies have shown that functional and structural changes take place in the cerebral cortex after injury, such as occurs after stroke or trauma. These two modulators of cortical function, sensorimotor learning and cortical injury, interact. Thus, after cortical injury, the structure and function of undamaged parts of the brain are remodeled during recovery, shaped by the sensorimotor experiences of the individual in the weeks to months following injury. These recent neuroscientific findings suggest that new rehabilitative interventions, both physiotherapeutic and pharmacotherapeutic, may have benefit via modulation of neuroplastic mechanisms. PMID:12817650

Nudo, Randolph J

2003-05-01

157

Cerebral asymmetry: a quantitative, multifactorial, and plastic brain phenotype.  

PubMed

The longitudinal fissure separates the human brain into two hemispheres that remain connected through the corpus callosum. The left and the right halves of the brain resemble each other, and almost every structure present in one side has an equivalent structure in the other. Despite this exceptional correspondence, the two hemispheres also display important anatomical differences and there is marked lateralization of certain cognitive and motor functions such as language and handedness. However, the mechanisms that underlie the establishment of these hemispheric specializations, as well as their physiological and behavioral implications, remain largely unknown. Thanks to recent advances in neuroimaging, a series of studies documenting variation in symmetry and asymmetry as a function of age, gender, brain region, and pathological state, have been published in the past decade. Here, we review evidence of normal and atypical cerebral asymmetry, and the factors that influence it at the macrostructural level. Given the prominent role that cerebral asymmetry plays in the organization of the brain, and its possible implication in neurodevelopmental and psychiatric conditions, further research in this area is anticipated. PMID:22856374

Rentería, Miguel E

2012-06-01

158

Atorvastatin induction of VEGF and BDNF promotes brain plasticity after stroke in mice  

Microsoft Academic Search

Molecular mechanisms underlying the role of statins in the induction of brain plasticity and subsequent improvement of neurologic outcome after treatment of stroke have not been adequately investigated. Here, we use both in vivo and in vitro studies to investigate the potential roles of two prominent factors, vascular endothelial growth factor (VEGF) and brain-derived neurotrophic factor (BDNF), in mediating brain

Jieli Chen; Chunling Zhang; Hao Jiang; Yi Li; Lijie Zhang; Adam Robin; Mark Katakowski; Mei Lu; Michael Chopp

2005-01-01

159

GABA through the Ages: Regulation of Cortical Function and Plasticity by Inhibitory Interneurons  

PubMed Central

Inhibitory interneurons comprise only about 20% of cortical neurons and thus constitute a clear minority compared to the vast number of excitatory projection neurons. They are, however, an influential minority with important roles in cortical maturation, function, and plasticity. In this paper, we will highlight the functional importance of cortical inhibition throughout brain development, starting with the embryonal formation of the cortex, proceeding by the regulation of sensory cortical plasticity in adulthood, and finishing with the GABA involvement in sensory information processing in old age.

Lehmann, Konrad; Steinecke, Andre; Bolz, Jurgen

2012-01-01

160

Determinants of the induction of cortical plasticity by non-invasive brain stimulation in healthy subjects  

PubMed Central

The ability to induce cortical plasticity with non-invasive brain stimulation (NBS) techniques has provided novel and exciting opportunities for examining the role of the human cortex during a variety of behaviours. Additionally, and importantly, the induction of lasting changes in cortical excitability can, under some conditions, reversibly modify behaviour and interact with normal learning. Such findings have driven a large number of recent studies examining whether by using such approaches it might be possible to induce functionally significant changes in patients with a large variety of neurological and psychiatric conditions including stroke, Parkinson's disease and depression. However, even in neurologically normal subjects the variability in the neurophysiological and behavioural response to such brain stimulation techniques is high. This variability at present limits the therapeutic usefulness of these techniques. The cause of this variability is multifactorial and to some degree still unknown. However, a number of factors that can influence the induction of plasticity have been identified. This review will summarise what is known about the causes of variability in healthy subjects and propose additional factors that are likely to be important determinants. A greater understanding of these determinants is critical for optimising the therapeutic applications of non-invasive brain stimulation techniques.

Ridding, M C; Ziemann, U

2010-01-01

161

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

162

Tensile Properties of Plasticized Pvc as a Function of Processing.  

National Technical Information Service (NTIS)

A statistical study was made of the tensile properties of plasticized PVC as a function of processing variables and environmental exposure. For this purpose, the performance of three polyester plasticizers was studied in a typical 105C. wire-coating formu...

C. D. Bias A. W. M. Coaker J. D. Hinchen

1967-01-01

163

Does induction of plastic change in motor cortex improve leg function after stroke?  

PubMed

Combined peripheral nerve and brain stimulation ("dual stimulation") induces changes in the excitability of normal motor cortex. The authors sought to establish whether dual stimulation would also induce motor cortex plasticity and associated functional improvements in nine stroke patients with chronic stable hemiparesis. Following 4 weeks of daily dual stimulation, improvements were seen in some neurophysiological and functional measures. This technique may offer therapeutic opportunities in some stroke patients. PMID:14557574

Uy, J; Ridding, M C; Hillier, S; Thompson, P D; Miles, T S

2003-10-14

164

SIRT1 is essential for normal cognitive function and synaptic plasticity  

PubMed Central

Conservation of normal cognitive functions relies on the proper performance of the nervous system at the cellular and molecular level. The mammalian NAD+-dependent deacetylase, SIRT1, impacts different processes potentially involved in the maintenance of brain integrity such as chromatin remodeling, DNA repair, cell survival and neurogenesis. Here we show that SIRT1 is expressed in neurons of the hippocampus, a key structure in learning and memory. Using a combination of behavioral and electrophysiological paradigms we analyzed the effects of SIRT1 deficiency and overexpression on mouse learning and memory as well as on synaptic plasticity. We demonstrated that the absence of SIRT1 impaired cognitive abilities, including immediate memory, classical conditioning and spatial learning. In addition, we found that the cognitive deficits in SIRT1 knockout mice were associated with defects in synaptic plasticity without alterations in basal synaptic transmission or NMDA receptor function. Brains of SIRT1-KO mice exhibited normal morphology and dendritic spine structure but display a decrease in dendritic branching, branch length and complexity of neuronal dendritic arbors. Also, a decrease in ERK1/2 phosphorylation and altered expression of hippocampal genes involved in synaptic function, lipid metabolism and myelination were detected in SIRT1-KO mice. In contrast, mice with high levels of SIRT1 expression in brain exhibited regular synaptic plasticity and memory. We conclude that SIRT1 is indispensable for normal learning, memory and synaptic plasticity in mice.

Michan, Shaday; Li, Ying; Chou, Maggie Meng-Hsiu; Parrella, Edoardo; Ge, Huanying; Long, Jeffrey M.; Allard, Joanne S.; Lewis, Kaitlyn; Miller, Marshall; Xu, Wei; Mervis, Ronald F.; Chen, Jing; Guerin, Karen I.; Smith, Lois E. H.; McBurney, Michael W.; Sinclair, David A.; Baudry, Michel; de Cabo, Rafael; Longo, Valter D.

2010-01-01

165

Activation of Rho GTPases triggers structural remodeling and functional plasticity in the adult rat visual cortex.  

PubMed

A classical example of age-dependent plasticity is ocular dominance (OD) plasticity, triggered by monocular deprivation (MD). Sensitivity of cortical circuits to a brief period of MD is maximal in juvenile animals and downregulated in adult age. It remains unclear whether a reduced potential for morphological remodeling underlies this downregulation of physiological plasticity in adulthood. Here we have tested whether stimulation of structural rearrangements is effective in promoting experience-dependent plasticity in adult age. We have exploited a bacterial protein toxin, cytotoxic necrotizing factor 1 (CNF1), that regulates actin dynamics and structure of neuronal processes via a persistent activation of Rho GTPases. Injection of CNF1 into the adult rat visual cortex triggered a long-lasting activation of the Rho GTPase Rac1, with a consequent increase in spine density and length in pyramidal neurons. Adult rats treated with CNF1, but not controls, showed an OD shift toward the open eye after MD. CNF1-mediated OD plasticity was selectively attributable to the enhancement of open-eye responses, whereas closed-eye inputs were unaffected. This effect correlated with an increased density of geniculocortical terminals in layer IV of monocularly deprived, CNF1-treated rats. Thus, Rho GTPase activation reinstates OD plasticity in the adult cortex via the potentiation of more active inputs from the open eye. These data establish a direct link between structural remodeling and functional plasticity and demonstrate a role for Rho GTPases in brain plasticity in vivo. The plasticizing effects of Rho GTPase activation may be exploited to promote brain repair. PMID:22016550

Cerri, Chiara; Fabbri, Alessia; Vannini, Eleonora; Spolidoro, Maria; Costa, Mario; Maffei, Lamberto; Fiorentini, Carla; Caleo, Matteo

2011-10-19

166

Task decomposition: a framework for comparing diverse training models in human brain plasticity studies  

PubMed Central

Training studies, in which the structural or functional neurophysiology is compared before and after expertise is acquired, are increasingly being used as models for understanding the human brain’s potential for reorganization. It is proving difficult to use these results to answer basic and important questions like how task training leads to both specific and general changes in behavior and how these changes correspond with modifications in the brain. The main culprit is the diversity of paradigms used as complex task models. An assortment of activities ranging from juggling to deciphering Morse code has been reported. Even when working in the same general domain, few researchers use similar training models. New ways to meaningfully compare complex tasks are needed. We propose a method for characterizing and deconstructing the task requirements of complex training paradigms, which is suitable for application to both structural and functional neuroimaging studies. We believe this approach will aid brain plasticity research by making it easier to compare training paradigms, identify “missing puzzle pieces,” and encourage researchers to design training protocols to bridge these gaps.

Coffey, Emily B. J.; Herholz, Sibylle C.

2013-01-01

167

Functional Brain Imaging in Apraxia  

Microsoft Academic Search

Background: An extensive literature describes struc- tural lesions in apraxia, but few studies have used func- tional neuroimaging. We used positron emission tomog- raphy (PET) to characterize relative cerebral glucose metabolism in a 65-year-old, right-handed woman with progressive decline in ability to manipulate objects, write, and articulate speech. Objective: To characterize functional brain organiza- tion in apraxia. Design and Methods:

David A. Kareken; Frederick Unverzagt; Karen Caldemeyer; Martin R. Farlow; Gary D. Hutchins

1998-01-01

168

N-Squad Episode 3. Students learn about alcoholâs effects on the brain, brain plasticity, brain parts, neurotransmission, addiction, withdrawal, factors influencing alcohol use, and drunk driving.  

NSDL National Science Digital Library

In N-Squad Episode 3 students work with forensic scientists to solve an alcohol related crime. Along the way, they will learn about alcoholâs effects on the brain, brain plasticity, brain parts, neurotransmission, addiction, withdrawal, factors influencing alcohol use, and drunk driving.

Learning, Center F.

2008-01-01

169

A role for synaptic plasticity in the adolescent development of executive function.  

PubMed

Adolescent brain maturation is characterized by the emergence of executive function mediated by the prefrontal cortex, e.g., goal planning, inhibition of impulsive behavior and set shifting. Synaptic pruning of excitatory contacts is the signature morphologic event of late brain maturation during adolescence. Mounting evidence suggests that glutamate receptor-mediated synaptic plasticity, in particular long-term depression (LTD), is important for elimination of synaptic contacts in brain development. This review examines the possibility (1) that LTD mechanisms are enhanced in the prefrontal cortex during adolescence due to ongoing synaptic pruning in this late developing cortex and (2) that enhanced synaptic plasticity in the prefrontal cortex represents a key molecular substrate underlying the critical period for maturation of executive function. Molecular sites of interaction between environmental factors, such as alcohol and stress, and glutamate receptor mediated plasticity are considered. The accentuated negative impact of these factors during adolescence may be due in part to interference with LTD mechanisms that refine prefrontal cortical circuitry and when disrupted derail normal maturation of executive function. Diminished prefrontal cortical control over risk-taking behavior could further exacerbate negative outcomes associated with these behaviors, as for example addiction and depression. Greater insight into the neurobiology of the adolescent brain is needed to fully understand the molecular basis for heightened vulnerability during adolescence to the injurious effects of substance abuse and stress. PMID:23462989

Selemon, L D

2013-03-05

170

Functional brain imaging across development.  

PubMed

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

Rubia, Katya

2012-06-24

171

Presynaptic NMDA Receptors: Newly Appreciated Roles in Cortical Synaptic Function and Plasticity  

PubMed Central

Many aspects of synaptic development, plasticity, and neurotransmission are critically influenced by NMDA-type glutamate receptors (NMDARs). Moreover, dysfunction of NMDARs has been implicated in a broad array of neurological disorders, including schizophrenia, stroke, epilepsy, and neuropathic pain. Classically, NMDARs were thought to be exclusively postsynaptic. However, substantial evidence in the last 10 years demonstrates that NMDARs also exist presynaptically, and that presynaptic NMDA receptors (preNMDARs) modulate synapse function and have critical roles in plasticity at many synapses. Here we review current knowledge of the role of preNMDARs in synaptic transmission and plasticity, focusing on the neocortex. We discuss the prevalence, function, and development of these receptors, and their potential modification by experience and in brain pathology.

Corlew, Rebekah; Brasier, Daniel J.; Feldman, Daniel E.; Philpot, Benjamin D.

2009-01-01

172

Introductory study of brain function data processing.  

National Technical Information Service (NTIS)

An investigational study was conducted of the brain function aiming at developing an interface with the same function as humans have. In the study, the most up-to-date information/knowledge and future problems were examined on brain measurement, brain mod...

1998-01-01

173

Task decomposition: a framework for comparing diverse training models in human brain plasticity studies.  

PubMed

Training studies, in which the structural or functional neurophysiology is compared before and after expertise is acquired, are increasingly being used as models for understanding the human brain's potential for reorganization. It is proving difficult to use these results to answer basic and important questions like how task training leads to both specific and general changes in behavior and how these changes correspond with modifications in the brain. The main culprit is the diversity of paradigms used as complex task models. An assortment of activities ranging from juggling to deciphering Morse code has been reported. Even when working in the same general domain, few researchers use similar training models. New ways to meaningfully compare complex tasks are needed. We propose a method for characterizing and deconstructing the task requirements of complex training paradigms, which is suitable for application to both structural and functional neuroimaging studies. We believe this approach will aid brain plasticity research by making it easier to compare training paradigms, identify "missing puzzle pieces," and encourage researchers to design training protocols to bridge these gaps. PMID:24115927

Coffey, Emily B J; Herholz, Sibylle C

2013-10-08

174

Research report Blindness and brain plasticity: contribution of mental imagery? An fMRI study  

Microsoft Academic Search

The purpose of this study was to study brain plasticity in the visual cortex, in six subjects totally blind from birth. The protocol we used was the same as that employed in a prior study on blindfolded sighted subjects (Brain Res., 924 (2002) 176). The production of mental images from animal names versus passive listening to abstract words, involved, in

S. Lamberta; E. Sampaioc; Y. Maussd; C. Scheiberd

175

Blindness and brain plasticity: contribution of mental imagery?An fMRI study  

Microsoft Academic Search

Abstract The purpose of this study was to study brain plasticity in the visual cortex, in six subjects totally blind from birth. The protocol we used was the same as that employed in a prior study on blindfolded sighted subjects (Brain Res., 924 (2002) 176). The production of mental images from animal names versus passive listening to abstract words, involved,

S. Lambert; E. Sampaio; Y. Mauss; C. Scheiber

2004-01-01

176

Applications of manganese-enhanced magnetic resonance imaging (MEMRI) to image brain plasticity in song birds  

Microsoft Academic Search

The song control system of song birds is an excellent model for studying brain plasticity and has thus far been extensively analyzed by histological and electrophysiological methods. However, these approaches do not provide a global view of the brain and\\/or do not allow repeated measures, which are necessary to establish correlations between alterations in neural substrate and behavior. Application of

Annemie Van der Linden; Vincent Van Meir; Ilse Tindemans; Marleen Verhoye; Jacques Balthazart

2004-01-01

177

Synthesis of Research on Brain Plasticity: The Classroom Environment and Curriculum Enrichment.  

ERIC Educational Resources Information Center

|Outlines research findings on enriched environment investigations on the development of the brain's neocortex. Although the research has been conducted on animal brains, researchers expect to find related patterns in plasticity in humans. The research is important to educators as it challenges them to define, create, and maintain an emotionally…

Sylwester, Robert

1986-01-01

178

Plasticity  

Microsoft Academic Search

Summary  Over the past 20 years, evidence has mounted regarding the capacity of the central nervous system to alter its structure and\\u000a function throughout life. Injury to the central nervous system appears to be a particularly potent trigger for plastic mechanisms\\u000a to be elicited. Following focal injury, widespread neurophysiological and neuroanatomical changes occur both in the peri-infarct\\u000a region, as well as

Randolph J. Nudo; Brian R. Christie; Andreas Frick; Richard Gray; Dax A. Hoffman; Lalania K. Schexnayder; Shigeo Watanabe; Li-Lian Yuan

2006-01-01

179

Brain Structure-function Couplings (FY11).  

National Technical Information Service (NTIS)

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

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

2012-01-01

180

Disrupted functional brain networks in autistic toddlers.  

PubMed

Communication and integration of information between brain regions plays a key role in healthy brain function. Conversely, disruption in brain communication may lead to cognitive and behavioral problems. Autism is a neurodevelopmental disorder that is characterized by impaired social interactions and aberrant basic information processing. Aberrant brain connectivity patterns have indeed been hypothesized to be a key neural underpinning of autism. In this study, graph analytical tools are used to explore the possible deviant functional brain network organization in autism at a very early stage of brain development. Electroencephalography (EEG) recordings in 12 toddlers with autism (mean age 3.5 years) and 19 control subjects were used to assess interregional functional brain connectivity, with functional brain networks constructed at the level of temporal synchronization between brain regions underlying the EEG electrodes. Children with autism showed a significantly increased normalized path length and reduced normalized clustering, suggesting a reduced global communication capacity already during early brain development. In addition, whole brain connectivity was found to be significantly reduced in these young patients suggesting an overall under-connectivity of functional brain networks in autism. Our findings support the hypothesis of abnormal neural communication in autism, with deviating effects already present at the early stages of brain development. PMID:23259692

Boersma, Maria; Kemner, Chantal; de Reus, Marcel A; Collin, Guusje; Snijders, Tineke M; Hofman, Dennis; Buitelaar, Jan K; Stam, Cornelis J; van den Heuvel, Martijn P

2013-01-01

181

Functional Coactivation Map of the Human Brain  

PubMed Central

Understanding the interactions among different brain regions is fundamental to our understanding of brain function. Here we describe a complete map of functional connections in the human brain derived by an automatic meta-analysis of 825 neuroimaging articles, representing 3402 experiments. The likelihood of a functional connection between regions was estimated by studying the interdependence of their “activity,” as reported in each experiment, across all experiments. We obtained a dense coactivation map that recovers some fundamental principles of the brain's functional connectivity, such as the symmetric interhemispheric connections, and important functional networks, such as the fronto-parietal attention network, the resting state network and the motor network.

Fox, Peter T.; Paus, Tomas

2008-01-01

182

Plasticity and reorganization during language development in children with early brain injury.  

PubMed

Although some studies have reported subtle language deficits following early focal brain lesions (EFBL), most studies find no evidence for differential language outcomes as a function of lesion side or lesion type in children with congenital injuries to one side of the brain. However, recent prospective studies of the first stages of language development in English-speaking children with EFBL have reported greater delays in expressive vocabulary in children with left-hemisphere damage, particularly if the lesion involves left temporal cortex. In the present study, first stages in the development of word production were studied in 43 Italian children with congenital EFBL, between 13 and 46 months of age. As a group, the EFBL children were markedly delayed in expressive vocabulary. Among children who were in the first stage of language learning, delays were significantly greater with left-hemisphere injury. However, this left-right difference was not evident in children who had moved on to the next stage of language development, producing at least some sentences. Discussion centers on the role of developmental plasticity in determining the outcomes of early focal brain injury, suggesting that recovery from initial delays may take place in the early stages of language development, at least for some children. PMID:10728895

Vicari, S; Albertoni, A; Chilosi, A M; Cipriani, P; Cioni, G; Bates, E

2000-02-01

183

[Role of androgen in the elderly. Modulation of synaptic plasticity by brain-synthesized androgens].  

PubMed

Recently, brain synthesis of androgen and estrogen has been extensively investigated. Steroidogenic enzymes and receptors are expressed in glutamatergic neurons. The expression levels of mRNA or proteins for enzymes are as low as 1/200 - 1/1,000. However, hippocampal levels of androgen and estrogen are much higher than those of plasma. This is due to the fact that the volume of hippocampus is as small as 1/200 of the blood vessels. Androgen and estrogen can rapidly modulate synaptic plasticity of neural circuits. After andropause or menopause, the levels of androgen and estrogen in the hippocampus may significantly decrease, inducing dementia, Alzheimer's or depression. Hormone replacement therapy is valid for rescue of memory function, therefore synthesis and action of hippocampal androgen and estrogen is an important field for investigations. PMID:23892214

Kawato, Suguru

2013-08-01

184

Norrin/Frizzled4 signaling in retinal vascular development and blood brain barrier plasticity  

PubMed Central

Norrin/Frizzled4 (Fz4) signaling activates the canonical Wnt pathway to control retinal vascular development. Using genetically engineered mice, we show that precocious Norrin production leads to premature retinal vascular invasion and delayed Norrin production leads to characteristic defects in intra-retinal vascular architecture. In genetic mosaics, wild type endothelial cells (ECs) instruct neighboring Fz4?/? ECs to produce an architecturally normal mosaic vasculature, a cell non-autonomous effect. However, over the ensuing weeks, Fz4?/? ECs are selectively eliminated from the mosaic vasculature, implying the existence of a quality control program that targets defective ECs. In the adult retina and cerebellum, gain or loss of Norrin/Fz4 signaling results in a cell-autonomous gain or loss, respectively, of blood retina barrier (BRB) and blood brain barrier (BBB) function, indicating an ongoing requirement for Frizzled signaling in barrier maintenance and substantial plasticity in mature CNS vascular structure.

Wang, Yanshu; Rattner, Amir; Zhou, Yulian; Williams, John; Smallwood, Philip M.; Nathans, Jeremy

2012-01-01

185

Exercise enhances and protects brain function.  

PubMed

Physical activity, in the form of voluntary wheel running, induces gene expression changes in the brain. Animals that exercise show an increase in brain-derived neurotrophic factor, a molecule that increases neuronal survival, enhances learning, and protects against cognitive decline. Microarray analysis of gene expression provides further support that exercise enhances and supports brain function. PMID:11991541

Cotman, Carl W; Engesser-Cesar, Christie

2002-04-01

186

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

187

Patterns of Normal Human Brain Plasticity After Practice and Their Implications for Neurorehabilitation  

Microsoft Academic Search

Kelly C, Foxe JJ, Garavan H. Patterns of normal human brain plasticity after practice and their im- plications for neurorehabilitation. Arch Phys Med Rehabil 2006;87(12 Suppl 2):S20-9. Objectives: To illustrate how our knowledge about normal patterns of experience-induced plasticity can provide insights into the mechanisms of neurorehabilitation; to provide an over- view of the practice-effects literature in order to simplify

Clare Kelly; John J. Foxe; Hugh Garavan

2006-01-01

188

Understanding neural plasticity for programming brain-machine systems  

Microsoft Academic Search

The rapidly emerging field of brain-machine interfaces (BMI) establishes a spectacular convergence between literature and neuroscience. But brain-machine interfaces emerge from two well-defined practical goals: creating more powerful computers and giving new hope to a broad segment of the disabled population. During the last century, the study of computers and of the brain have evolved in a reciprocal metaphor: the

F. Mussa-Ivaldi

2003-01-01

189

Early Life Stress Differentially Modulates Distinct Forms of Brain Plasticity in Young and Adult Mice  

PubMed Central

Background Early life trauma is an important risk factor for many psychiatric and somatic disorders in adulthood. As a growing body of evidence suggests that brain plasticity is disturbed in affective disorders, we examined the short-term and remote effects of early life stress on different forms of brain plasticity. Methodology/Principal Findings Mice were subjected to early deprivation by individually separating pups from their dam in the first two weeks after birth. Distinct forms of brain plasticity were assessed in the hippocampus by longitudinal MR volumetry, immunohistochemistry of neurogenesis, and whole-cell patch-clamp measurements of synaptic plasticity. Depression-related behavior was assessed by the forced swimming test in adult animals. Neuropeptides and their receptors were determined by real-time PCR and immunoassay. Early maternal deprivation caused a loss of hippocampal volume, which returned to normal in adulthood. Adult neurogenesis was unaffected by early life stress. Long-term synaptic potentiation, however, was normal immediately after the end of the stress protocol but was impaired in adult animals. In the forced swimming test, adult animals that had been subjected to early life stress showed increased immobility time. Levels of substance P were increased both in young and adult animals after early deprivation. Conclusion Hippocampal volume was affected by early life stress but recovered in adulthood which corresponded to normal adult neurogenesis. Synaptic plasticity, however, exhibited a delayed impairment. The modulation of synaptic plasticity by early life stress might contribute to affective dysfunction in adulthood.

Reichardt, Wilfried; Clark, Kristin; Geiger, Julia; Gross, Claus M.; Heyer, Andrea; Neagu, Valentin; Bhatia, Harsharan; Atas, Hasan C.; Fiebich, Bernd L.; Bischofberger, Josef; Haas, Carola A.; Normann, Claus

2012-01-01

190

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

Microsoft Academic Search

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

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

2011-01-01

191

Reversed timing-dependent associative plasticity in the human brain through interhemispheric interactions.  

PubMed

Spike timing-dependent plasticity (STDP) has been proposed as one of the key mechanisms underlying learning and memory. Repetitive median nerve stimulation, followed by transcranial magnetic stimulation (TMS) of the contralateral primary motor cortex (M1), defined as paired-associative stimulation (PAS), has been used as an in vivo model of STDP in humans. PAS-induced excitability changes in M1 have been repeatedly shown to be time-dependent in a STDP-like fashion, since synchronous arrival of inputs within M1 induces long-term potentiation-like effects, whereas an asynchronous arrival induces long-term depression (LTD)-like effects. Here, we show that interhemispheric inhibition of the sensorimotor network during PAS, with the peripheral stimulation over the hand ipsilateral to the motor cortex receiving TMS, results in a LTD-like effect, as opposed to the standard STDP-like effect seen for contralateral PAS. Furthermore, we could show that this reversed-associative plasticity critically depends on the timing interval between afferent and cortical stimulation. These results indicate that the outcome of associative stimulation in the human brain depends on functional network interactions (inhibition or facilitation) at a systems level and can either follow standard or reversed STDP-like mechanisms. PMID:23407353

Conde, Virginia; Vollmann, Henning; Taubert, Marco; Sehm, Bernhard; Cohen, Leonardo G; Villringer, Arno; Ragert, Patrick

2013-02-13

192

Is brain plasticity preserved during aging and in Alzheimer's disease?  

Microsoft Academic Search

Alzheimer's disease is a progressive neurodegenerative disorder believed to involve selective neuronal cell atrophy\\/loss in certain brain regions. The progress of the disease is accompanied by selective cognitive impairments and behavioral disturbances. The hypothesis has been put forward that by activation of selective brain areas throughout life one might protect or delay the degenerative process. This hypothesis, paraphrased as “a

M. Mirmiran; E. J. W. van Someren; D. F. Swaab

1996-01-01

193

Neurons, glia, and plasticity in normal brain aging  

Microsoft Academic Search

Early manifestations of brain aging have received much less attention than the drastic degeneration of AD and MID. During nonpathological changes of normal aging, brain systems differ in the involvement of neuron loss. Spatial learning can become impaired without evidence for neuron loss, whereas eye-blink conditioning deficits are well correlated with Purkinje neuron loss. Glial activation, in particular the increased

Caleb E. Finch

2003-01-01

194

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

195

Remodeling the Brain Plastic Structural Brain Changes Produced by Different Motor Therapies After Stroke  

Microsoft Academic Search

Background and Purpose—Studies on adult stroke patients have demonstrated functional changes in cortical excitability, metabolic rate, or blood flow after motor therapy, measures that can fluctuate rapidly over time. This study evaluated whether evidence could also be found for structural brain changes during an efficacious rehabilitation program. Methods—Chronic stroke patients were randomly assigned to receive either constraint-induced movement therapy (n16)

Lynne V. Gauthier; Edward Taub; Christi Perkins; Magdalene Ortmann; Victor W. Mark; Gitendra Uswatte

2010-01-01

196

Conditional Transgenesis and Recombination to Study the Molecular Mechanisms of Brain Plasticity and Memory  

Microsoft Academic Search

In the postgenomic era, a primary focus of mouse genetics is to elucidate the role of individual genesin vivo. However, in the nervous system, studying the contribution of specific genes to brain functions is difficult because the brain is a highly complex organ with multiple neuroanatomical structures, orchestrating virtually every function in the body. Further, higher-order brain functions such as

K. Baumgärtel; C. Fernández; T. Johansson; I. Mansuy

197

Pulmonary functions in plastic factory workers: a preliminary study.  

PubMed

Exposure to long term air pollution in the work environment may result in decreased lung functions and various other health problems. A significant occupational hazard to lung functions is experienced by plastic factory workers. The present study is planned to assess the pulmonary functions of workers in the plastic factory where recycling of pastic material was done. These workers were constantly exposed to fumes of various chemicals throughout the day. Thirty one workers of plastic factory were assessed for their pulmonary functions. Parameters were compared with 31 age and sex matched controls not exposed to the same environment. The pulmonary function tests were done using Sibelmed Datospir 120 B portable spirometer. A significant decrease in most of the flow rates (MEF 25%, MEF 50%, MEF 75% and FEF 25-75%) and most of the lung volumes and capacities (FVC, FEV1, VC, TV, ERV, MVV) were observed in the workers. Smoking and duration of exposure were not affecting the lung functions as the non smokers also showed a similar decrement in pulmonary functions. Similarly the workers working for less than 5 years also had decrement in pulmonary functions indicating that their lungs are being affected even if they have worked for one year. Exposure to the organic dust in the work environment should be controlled by adequate engineering measures, complemented by effective personal respiratory protection. PMID:22315811

Khaliq, Farah; Singh, Pawan; Chandra, Prakash; Gupta, Keshav; Vaney, Neelam

198

The functional plasticity of T cell subsets  

Microsoft Academic Search

In 1986, Robert Coffman and Timothy Mossman first described the division of CD4+ T cells into functional subsets, termed T helper 1 (TH1) and TH2, based on cytokine production, and in doing so unwittingly opened a Pandora's box of complexity and controversy. Although the mechanisms that regulate TH1 and TH2 cells are now well known, recent descriptions of other CD4+

Jeffrey A. Bluestone; Charles R. Mackay; John J. O'Shea; Brigitta Stockinger

2009-01-01

199

Brain Function. Volume IV. Brain Function and Learning.  

National Technical Information Service (NTIS)

Contents: Neurochemical approaches to learning, by John Gaito; Electrical events in the brain and learning, by Robert Galambos; Neurophysiology and learning -- Memory and the organization of attention, by Karl H. Pribram, and A 'model neural system' appro...

D. B. Lindsley A. A. Lumsdaine

1967-01-01

200

Scaling of Brain Metabolism with a Fixed Energy Budget per Neuron: Implications for Neuronal Activity, Plasticity and Evolution  

PubMed Central

It is usually considered that larger brains have larger neurons, which consume more energy individually, and are therefore accompanied by a larger number of glial cells per neuron. These notions, however, have never been tested. Based on glucose and oxygen metabolic rates in awake animals and their recently determined numbers of neurons, here I show that, contrary to the expected, the estimated glucose use per neuron is remarkably constant, varying only by 40% across the six species of rodents and primates (including humans). The estimated average glucose use per neuron does not correlate with neuronal density in any structure. This suggests that the energy budget of the whole brain per neuron is fixed across species and brain sizes, such that total glucose use by the brain as a whole, by the cerebral cortex and also by the cerebellum alone are linear functions of the number of neurons in the structures across the species (although the average glucose consumption per neuron is at least 10× higher in the cerebral cortex than in the cerebellum). These results indicate that the apparently remarkable use in humans of 20% of the whole body energy budget by a brain that represents only 2% of body mass is explained simply by its large number of neurons. Because synaptic activity is considered the major determinant of metabolic cost, a conserved energy budget per neuron has several profound implications for synaptic homeostasis and the regulation of firing rates, synaptic plasticity, brain imaging, pathologies, and for brain scaling in evolution.

Herculano-Houzel, Suzana

2011-01-01

201

Cortical plasticity and preserved function in early blindness.  

PubMed

The "neural Darwinism" theory predicts that when one sensory modality is lacking, as in congenital blindness, the target structures are taken over by the afferent inputs from other senses that will promote and control their functional maturation (Edelman, 1993). This view receives support from both cross-modal plasticity experiments in animal models and functional imaging studies in man, which are presented here. PMID:23453908

Renier, Laurent; De Volder, Anne G; Rauschecker, Josef P

2013-02-20

202

In vivo imaging of neuronal activation and plasticity in the rat brain by high resolution positron emission tomography (microPET)  

Microsoft Academic Search

The study of neural repair and neuroplasticity in rodents would be enhanced by the ability to assess neuronal function in vivo. Positron emission tomography (PET) is used to study brain plasticity in humans, but the limited resolution and sensitivity of conventional scanners have generally precluded the use of PET to study neuroplasticity in rodents. We now demonstrate that microPET, a

Dalia M. Araujo; Alexander J. Annala; Keith J. Tatsukawa; Michael E. Phelps; Simon R. Cherry; Harley I. Kornblum

2000-01-01

203

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

204

Energetic cost of brain functional connectivity.  

PubMed

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

2013-07-29

205

The gravitational field and brain function  

NASA Astrophysics Data System (ADS)

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

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

206

Evidence for Training-Induced Plasticity in Multisensory Brain Structures: An MEG Study  

Microsoft Academic Search

Multisensory learning and resulting neural brain plasticity have recently become a topic of renewed interest in human cognitive neuroscience. Music notation reading is an ideal stimulus to study multisensory learning, as it allows studying the integration of visual, auditory and sensorimotor information processing. The present study aimed at answering whether multisensory learning alters uni-sensory structures, interconnections of uni-sensory structures or

Evangelos Paraskevopoulos; Anja Kuchenbuch; Sibylle C. Herholz; Christo Pantev

2012-01-01

207

Principles of Experience-Dependent Neural Plasticity: Implications for Rehabilitation after Brain Damage  

ERIC Educational Resources Information Center

|Purpose: This paper reviews 10 principles of experience-dependent neural plasticity and considerations in applying them to the damaged brain. Method: Neuroscience research using a variety of models of learning, neurological disease, and trauma are reviewed from the perspective of basic neuroscientists but in a manner intended to be useful for the…

Kleim, Jeffrey A.; Jones, Theresa A.

2008-01-01

208

Effects of sexual behavioral manipulation on brain plasticity in adult rats  

Microsoft Academic Search

The purpose of the present study was to determine the effects of sexual behaviorial manipulation on brain plasticity in adult male rats. Adult male Sprague-Dawley rats that copulated during male sexual behavior testing were divided into four groups: control male; gonadectomized (Gdx) male; sexually active male; and sexually nonactive male. Female animals were used as an additional control group. At

Karianne N. Prince; Jeffrey S. Prince; Edward W. Kinghorn; Donovan E. Fleming; Reuben W. Rhees

1998-01-01

209

Brain Function: Implications for Schooling.  

ERIC Educational Resources Information Center

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

Edwards, Clifford H.

1982-01-01

210

Thyroid function in brain-dead donors  

Microsoft Academic Search

Twenty brain-dead potential organ donors were studied prospectively to establish thyroid function. Two or three consecutive blood samples were obtained during brain death. Seven times a sample was available before brain death occurred. Free triiodothyronine (FT3) fell in most patients (80%). Very low (<1.6 pmol\\/l) and subnormal levels (between 2 and 3 pmol\\/l) were found in 65% and 15% of

F. Masson; M. Thicoïpe; M. J. Latapie; P. Maurette

1990-01-01

211

Functional Aspects of Creatine Kinase in Brain  

Microsoft Academic Search

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

Wolfram Hemmer; Theo Wallimann

1993-01-01

212

Brain Melanocortin Receptors: From Cloning to Function  

Microsoft Academic Search

Adan R. A. H., W. H. Gispen.Brain melanocortin receptors: from cloning to function.Peptides 18(8) 1279–1287, 1997.—The cloning of brain melanocortin (MC) receptors, the mapping of their expression pattern and the identification of MC receptor selective ligands have opened a new avenue towards elucidating the role of the melanocortin system in the brain. MC receptors have now been implicated in melanocortin-induced

Roger A. H Adan; Willem Hendrik Gispen

1997-01-01

213

Brain plasticity and recovery from early cortical injury.  

PubMed

Neocortical development represents more than a simple unfolding of a genetic blueprint: rather, it represents a complex dance of genetic and environmental events that interact to adapt the brain to fit a particular environmental context. Most cortical regions are sensitive to a wide range of experiential factors during development and later in life, but the injured cortex appears to be unusually sensitive to perinatal experiences. This paper reviews the factors that influence how normal and injured brains (both focal and ischemic injuries) develop and adapt into adulthood. Such factors include prenatal experiences in utero as well as postnatal experiences throughout life. Examples include the effects of sensory and motor stimulation, psychoactive drugs (including illicit and prescription drugs), maternal and postnatal stress, neurotrophic factors, and pre- and postnatal diet. All these factors influence cerebral development and influence recovery from brain injury during development. PMID:21950386

Kolb, Bryan; Mychasiuk, Richelle; Williams, Preston; Gibb, Robbin

2011-09-01

214

Brain functional networks analysis and comparison  

Microsoft Academic Search

This study used the complex network analysis to examine the brain functional network involved in right finger movements and compare the deferent functional network involved in left finger and right finger movements. We found that (a)the connections change exponentially as distance between nodes change, the function is Gaussian; (b) the distribution of functional connections was scale-free; (c) the typical path

Fangfeng Zhang; Chunhui Chen; Lu Jiang

2010-01-01

215

Simple models of human brain functional networks  

PubMed Central

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.

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

2012-01-01

216

On development of functional brain connectivity in the young brain  

PubMed Central

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

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

2013-01-01

217

Plastic brain mechanisms for attaining auditory temporal order judgment proficiency  

Microsoft Academic Search

Accurate perception of the order of occurrence of sensory information is critical for the building up of coherent representations of the external world from ongoing flows of sensory inputs. While some psychophysical evidence reports that performance on temporal perception can improve, the underlying neural mechanisms remain unresolved. Using electrical neuroimaging analyses of auditory evoked potentials (AEPs), we identified the brain

Fosco Bernasconi; Jeremy Grivel; Micah M. Murray; Lucas Spierer

2010-01-01

218

The Histaminergic System in Brain: Memory and Synaptic Plasticity  

Microsoft Academic Search

Among the aminergic systems in the brain the histaminergic system has received the least attention although it is equally important. The relatively small groups of neurons containing acetylcholine, noradrenaline, dopamine, serotonin and histamine display comparable electrophysiological properties and morphological features. They all project with multifold arborintion to most regions of the central nervous system with some notable distinctions between them.

Oliver Selbach; Olga Sergeeva; Helmut L. Haas

219

Lead poisoning and brain cell function  

Microsoft Academic Search

Exposure to excessive amounts of inorganic lead during the toddler years may produce lasting adverse effects upon brain function. Maximal ingestion of lead occurs at an age when major changes are occurring in the density of brain synaptic connections. The developmental reorganization of synapses is, in part, mediated by protein kinases, and these enzymes are particularly sensitive to stimulation by

Goldstein

1990-01-01

220

Brain function, injury and disease: an introduction  

Microsoft Academic Search

This paper sets out to provide a brief guide to brain function and the main causes of brain dysfunction likely to be encountered in social care and neurodisability practice. For the first issue of Social Care and Neurodisability, it was felt that such an overview paper serving both as a self-contained aide memoire, and as a ‘signpost’ for other relevant

Keith G Jenkins; Louise Birkett-Swan

2010-01-01

221

Brain spontaneous functional connectivity and intelligence  

Microsoft Academic Search

Many functional imaging studies have been performed to explore the neural basis of intelligence by detecting brain activity changes induced by intelligence-related tasks, such as reasoning or working memory. However, little is known about whether the spontaneous brain activity at rest is relevant to the differences in intelligence. Here, 59 healthy adult subjects (Wechsler Adult Intelligence Scale score, 90–138) were

Ming Song; Yuan Zhou; Jun Li; Yong Liu; Lixia Tian; Chunshui Yu; Tianzi Jiang

2008-01-01

222

Structural and Functional Brain Abnormalities in Schizophrenia  

Microsoft Academic Search

Schizophrenia is associated with changes in the structure and functioning of a number of key brain systems, including prefrontal and medial temporal lobe regions involved in working memory and declarative memory, respectively. Imaging techniques provide an unparalleled window into these changes, allowing repeated assessments across pre- and post-onset stages of the disorder and in relation to critical periods of brain

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

2010-01-01

223

Prentice award lecture 2011: removing the brakes on plasticity in the amblyopic brain.  

PubMed

Experience-dependent plasticity is closely linked with the development of sensory function. Beyond this sensitive period, developmental plasticity is actively limited; however, new studies provide growing evidence for plasticity in the adult visual system. The amblyopic visual system is an excellent model for examining the "brakes" that limit recovery of function beyond the critical period. While amblyopia can often be reversed when treated early, conventional treatment is generally not undertaken in older children and adults. However, new clinical and experimental studies in both animals and humans provide evidence for neural plasticity beyond the critical period. The results suggest that perceptual learning and video game play may be effective in improving a range of visual performance measures and importantly the improvements may transfer to better visual acuity and stereopsis. These findings, along with the results of new clinical trials, suggest that it might be time to reconsider our notions about neural plasticity in amblyopia. PMID:22581119

Levi, Dennis M

2012-06-01

224

FUNCTIONAL IMAGING OF BRAIN TUMORS  

Microsoft Academic Search

Conventional imaging techniques, such as computed tomography (CT) and magnetic resonance imaging (MR), are of immeasurable assistance in the diagnosis and characterization of primary intracranial tumors. Factors which can be accurately deduced via these techniques includes the location, size, mass effect and edema associated with brain tumors; usually a differential diagnosis of tumor type can be generated based on characteristics

Ferenc A. Jolesz

225

Functional brain development in humans  

Microsoft Academic Search

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

Mark H. Johnson

2001-01-01

226

Scale-free brain functional networks  

Microsoft Academic Search

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

Victor M. Egu ´ õluz; Dante R. Chialvo; Guillermo A. Cecchi; Marwan Baliki; A. Vania Apkarian

2005-01-01

227

Modeling of functional brain imaging data  

NASA Astrophysics Data System (ADS)

The richness and complexity of data sets obtained from functional neuroimaging studies of human cognitive behavior, using techniques such as positron emission tomography and functional magnetic resonance imaging, have until recently not been exploited by computational neural modeling methods. In this article, following a brief introduction to functional neuroimaging methodology, two neural modeling approaches for use with functional brain imaging data are described. One, which uses structural equation modeling, examines the effective functional connections between various brain regions during specific cognitive tasks. The second employs large-scale neural modeling to relate functional neuroimaging signals in multiple, interconnected brain regions to the underlying neurobiological time-varying activities in each region. These two modeling procedures are illustrated using a visual processing paradigm.

Horwitz, Barry

1999-03-01

228

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.

Sporns, Olaf

2013-01-01

229

Remaining Flexible in Old Alliances: Functional Plasticity in Constrained Mutualisms  

PubMed Central

Central to any beneficial interaction is the capacity of partners to detect and respond to significant changes in the other. Recent studies of microbial mutualists show their close integration with host development, immune responses, and acclimation to a dynamic external environment. While the significance of microbial players is broadly appreciated, we are just beginning to understand the genetic, ecological, and physiological mechanisms that generate variation in symbiont functions, broadly termed “symbiont plasticity” here. Some possible mechanisms include shifts in symbiont community composition, genetic changes via DNA acquisition, gene expression fluctuations, and variation in symbiont densities. In this review, we examine mechanisms for plasticity in the exceptionally stable mutualisms between insects and bacterial endosymbionts. Despite the severe ecological and genomic constraints imposed by their specialized lifestyle, these bacteria retain the capacity to modulate functions depending on the particular requirements of the host. Focusing on the mutualism between Blochmannia and ants, we discuss the roles of gene expression fluctuations and shifts in bacterial densities in generating symbiont plasticity. This symbiont variation is best understood by considering ant colony as the host superorganism. In this eusocial host, the bacteria meet the needs of the colony and not necessarily the individual ants that house them.

Wheeler, Diana E.

2009-01-01

230

Frequency representation within the human brain: Stability versus plasticity  

PubMed Central

A topographical representation for frequency has been identified throughout the auditory brain in animals but with limited evidence in humans. Using a midbrain implant, we identified an ordering of pitch percepts for electrical stimulation of sites across the human inferior colliculus (IC) that was consistent with the IC tonotopy shown in animals. Low pitches were perceived by the subject for stimulation of superficial IC sites while higher pitches were perceived for stimulation of deeper sites. Interestingly, this pitch ordering was not initially observed for stimulation across the IC, possibly due to central changes caused by prior hearing loss. Daily implant stimulation for about 4?months altered the pitch percepts from being predominantly low to exhibiting the expected ordering across the stimulated IC. A presumably normal tonotopic representation may have been maintained within the IC or accessible through IC stimulation that helped form this pitch ordering perceived in higher centers.

Lim, Hubert H.; Lenarz, Minoo; Joseph, Gert; Lenarz, Thomas

2013-01-01

231

Cognitive aging as an extension of brain development: A model linking learning, brain plasticity, and neurodegeneration  

Microsoft Academic Search

Differences in cognitive aging rates among mammals suggest that the pace of brain aging is genetically determined. In this work, we investigate the possibility that brain aging is an extension of brain development. It is possible that a subset of developmental mechanisms are extreme cases of antagonistic pleiotropy in that they are necessary for reaching adulthood and yet later cause

João Pedro de Magalhães; Anders Sandberg

2005-01-01

232

Characterizing Brain Cortical Plasticity and Network Dynamics Across the Age-Span in Health and Disease with TMS-EEG and TMS-fMRI  

PubMed Central

Brain plasticity can be conceptualized as nature’s invention to overcome limitations of the genome and adapt to a rapidly changing environment. As such, plasticity is an intrinsic property of the brain across the life-span. However, mechanisms of plasticity may vary with age. The combination of transcranial magnetic stimulation (TMS) with electroencephalography (EEG) or functional magnetic resonance imaging (fMRI) enables clinicians and researchers to directly study local and network cortical plasticity, in humans in vivo, and characterize their changes across the age-span. Parallel, translational studies in animals can provide mechanistic insights. Here, we argue that, for each individual, the efficiency of neuronal plasticity declines throughout the age-span and may do so more or less prominently depending on variable ‘starting-points’ and different ‘slopes of change’ defined by genetic, biological, and environmental factors. Furthermore, aberrant, excessive, insufficient, or mistimed plasticity may represent the proximal pathogenic cause of neurodevelopmental and neurodegenerative disorders such as autism spectrum disorders or Alzheimer’s disease.

Pascual-Leone, Alvaro; Freitas, Catarina; Oberman, Lindsay; Horvath, Jared C.; Halko, Mark; Eldaief, Mark; Bashir, Shahid; Vernet, Marine; Shafi, Mouhshin; Westover, Brandon; Vahabzadeh-Hagh, Andrew M.; Rotenberg, Alexander

2012-01-01

233

Inhibition of neocortical plasticity during development by a moderate concussive brain injury.  

PubMed

To determine if a moderate traumatic brain injury (TBI) sustained early in life alters the capacity for developmental plasticity, 17-20-day-old rat pups received a lateral fluid percussion and then reared in an enriched environment for 17 days. Compared to sham-injured controls, this moderate TBI prevented the increase in cortical thickness (1.48 vs. 1.68 mm, p < 0.01) as well as the corresponding enhancement in cognitive performance in the Morris Water Maze (39 vs. 25 trials to criterion, p < 0.05). These injured animals exhibited no significant neuronal degeneration and no evidence of neurologic or motor deficits. These findings strongly support the conclusion that a diffuse brain injury is capable of inhibiting both anatomical and cognitive manifestations of experience-dependent developmental plasticity. PMID:11011814

Fineman, I; Giza, C C; Nahed, B V; Lee, S M; Hovda, D A

2000-09-01

234

Mushroom bodies of the honeybee brain show cell population-specific plasticity in expression of amine-receptor genes.  

PubMed

Dopamine and octopamine released in the mushroom bodies of the insect brain play a critical role in the formation of aversive and appetitive memories, respectively. As recent evidence suggests a complex relationship between the effects of these two amines on the output of mushroom body circuits, we compared the expression of dopamine- and octopamine-receptor genes in three major subpopulations of mushroom body intrinsic neurons (Kenyon cells). Using the brain of the honeybee, Apis mellifera, we found that expression of amine-receptor genes differs markedly across Kenyon cell subpopulations. We found, in addition, that levels of expression of these genes change dramatically during the lifetime of the bee and that shifts in expression are cell population-specific. Differential expression of amine-receptor genes in mushroom body neurons and the plasticity that exists at this level are features largely ignored in current models of mushroom body function. However, our results are consistent with the growing body of evidence that short- and long-term olfactory memories form in different regions of the mushroom bodies of the brain and that there is functional compartmentalization of the modulatory inputs to this multifunctional brain center. PMID:22411422

McQuillan, H James; Nakagawa, Shinichi; Mercer, Alison R

2012-03-12

235

Brain plasticity through the life span: learning to learn and action video games.  

PubMed

The ability of the human brain to learn is exceptional. Yet, learning is typically quite specific to the exact task used during training, a limiting factor for practical applications such as rehabilitation, workforce training, or education. The possibility of identifying training regimens that have a broad enough impact to transfer to a variety of tasks is thus highly appealing. This work reviews how complex training environments such as action video game play may actually foster brain plasticity and learning. This enhanced learning capacity, termed learning to learn, is considered in light of its computational requirements and putative neural mechanisms. PMID:22715883

Bavelier, Daphne; Green, C Shawn; Pouget, Alexandre; Schrater, Paul

2012-01-01

236

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

2010-02-22

237

Toward discovery science of human brain function  

PubMed Central

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/.

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.; Kotter, 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.

2010-01-01

238

The Radical Plasticity Thesis: How the Brain Learns to be Conscious  

PubMed Central

In this paper, I explore the idea that consciousness is something that the brain learns to do rather than an intrinsic property of certain neural states and not others. Starting from the idea that neural activity is inherently unconscious, the question thus becomes: How does the brain learn to be conscious? I suggest that consciousness arises as a result of the brain's continuous attempts at predicting not only the consequences of its actions on the world and on other agents, but also the consequences of activity in one cerebral region on activity in other regions. By this account, the brain continuously and unconsciously learns to redescribe its own activity to itself, so developing systems of meta-representations that characterize and qualify the target first-order representations. Such learned redescriptions, enriched by the emotional value associated with them, form the basis of conscious experience. Learning and plasticity are thus central to consciousness, to the extent that experiences only occur in experiencers that have learned to know they possess certain first-order states and that have learned to care more about certain states than about others. This is what I call the “Radical Plasticity Thesis.” In a sense thus, this is the enactive perspective, but turned both inwards and (further) outwards. Consciousness involves “signal detection on the mind”; the conscious mind is the brain's (non-conceptual, implicit) theory about itself. I illustrate these ideas through neural network models that simulate the relationships between performance and awareness in different tasks.

Cleeremans, Axel

2011-01-01

239

Arm Training Induced Brain Plasticity in Stroke Studied with Serial Positron Emission Tomography1  

Microsoft Academic Search

We used serial positron emission tomography (PET) to study training-induced brain plasticity after severe hemiparetic stroke. Ten patients were randomized to either task-oriented arm training or to a control group and scanned before and after 22.6 6 1.6 days of treat- ment using passive movements as an activation para- digm. Increases of regional cerebral blood flow (rCBF) were assessed using

G. Nelles; W. Jentzen; M. Jueptner; S. Muller; H. C. Diener

240

Arm Training Induced Brain Plasticity in Stroke Studied with Serial Positron Emission Tomography  

Microsoft Academic Search

We used serial positron emission tomography (PET) to study training-induced brain plasticity after severe hemiparetic stroke. Ten patients were randomized to either task-oriented arm training or to a control group and scanned before and after 22.6 ± 1.6 days of treatment using passive movements as an activation paradigm. Increases of regional cerebral blood flow (rCBF) were assessed using statistical parametric

G. Nelles; W. Jentzen; M. Jueptner; S. Müller; H. C. Diener

2001-01-01

241

Effect of ephedrine on neuronal plasticity of hypoxic-ischemic brain damage in neonatal rats  

Microsoft Academic Search

Objective: Study the effect of ephedrine on neural plasticity of hypoxic ischemic brain damaged (HIBD) in neonatal rats, and explore the underlying molecular mechanism. Methods: 60 Sprats suffered from HIBD (7 days old) were randomly divided into ephedrine group, d-amphetamine (d-AMPH) group, cytidine triphosphate (CTP) group, ganglioside (GM1) group, and spontaneous recovery group. Using immunohistochemical method to test the expression

Nong Xiao; Shizhi Li; Xiaoping Zhang; Siyuan Chen

2008-01-01

242

Brain connectivity plasticity in the motor network after ischemic stroke.  

PubMed

The motor function is controlled by the motor system that comprises a series of cortical and subcortical areas interacting via anatomical connections. The motor function will be disturbed when the stroke lesion impairs either any of these areas or their connections. More and more evidence indicates that the reorganization of the motor network including both areas and their anatomical and functional connectivity might contribute to the motor recovery after stroke. Here, we review recent studies employing models of anatomical, functional, and effective connectivity on neuroimaging data to investigate how ischemic stroke influences the connectivity of motor areas and how changes in connectivity relate to impaired function and functional recovery. We suggest that connectivity changes constitute an important pathophysiological aspect of motor impairment after stroke and important mechanisms of motor recovery. We also demonstrate that therapeutic interventions may facilitate motor recovery after stroke by modulating the connectivity among the motor areas. In conclusion, connectivity analyses improved our understanding of the mechanisms of motor recovery after stroke and may help to design hypothesis-driven treatment strategies and sensitive measures for outcome prediction in stroke patients. PMID:23738150

Jiang, Lin; Xu, Huijuan; Yu, Chunshui

2013-04-24

243

Why and How Physical Activity Promotes Experience-Induced Brain Plasticity  

PubMed Central

Adult hippocampal neurogenesis is an unusual case of brain plasticity, since new neurons (and not just neurites and synapses) are added to the network in an activity-dependent way. At the behavioral level the plasticity-inducing stimuli include both physical and cognitive activity. In reductionistic animal studies these types of activity can be studied separately in paradigms like voluntary wheel running and environmental enrichment. In both of these, adult neurogenesis is increased but the net effect is primarily due to different mechanisms at the cellular level. Locomotion appears to stimulate the precursor cells, from which adult neurogenesis originates, to increased proliferation and maintenance over time, whereas environmental enrichment, as well as learning, predominantly promotes survival of immature neurons, that is the progeny of the proliferating precursor cells. Surprisingly, these effects are additive: boosting the potential for adult neurogenesis by physical activity increases the recruitment of cells following cognitive stimulation in an enriched environment. Why is that? We argue that locomotion actually serves as an intrinsic feedback mechanism, signaling to the brain, including its neural precursor cells, increasing the likelihood of cognitive challenges. In the wild (other than in front of a TV), no separation of physical and cognitive activity occurs. Physical activity might thus be much more than a generally healthy garnish to leading “an active life” but an evolutionarily fundamental aspect of “activity,” which is needed to provide the brain and its systems of plastic adaptation with the appropriate regulatory input and feedback.

Kempermann, Gerd; Fabel, Klaus; Ehninger, Dan; Babu, Harish; Leal-Galicia, Perla; Garthe, Alexander; Wolf, Susanne A.

2010-01-01

244

Why and how physical activity promotes experience-induced brain plasticity.  

PubMed

Adult hippocampal neurogenesis is an unusual case of brain plasticity, since new neurons (and not just neurites and synapses) are added to the network in an activity-dependent way. At the behavioral level the plasticity-inducing stimuli include both physical and cognitive activity. In reductionistic animal studies these types of activity can be studied separately in paradigms like voluntary wheel running and environmental enrichment. In both of these, adult neurogenesis is increased but the net effect is primarily due to different mechanisms at the cellular level. Locomotion appears to stimulate the precursor cells, from which adult neurogenesis originates, to increased proliferation and maintenance over time, whereas environmental enrichment, as well as learning, predominantly promotes survival of immature neurons, that is the progeny of the proliferating precursor cells. Surprisingly, these effects are additive: boosting the potential for adult neurogenesis by physical activity increases the recruitment of cells following cognitive stimulation in an enriched environment. Why is that? We argue that locomotion actually serves as an intrinsic feedback mechanism, signaling to the brain, including its neural precursor cells, increasing the likelihood of cognitive challenges. In the wild (other than in front of a TV), no separation of physical and cognitive activity occurs. Physical activity might thus be much more than a generally healthy garnish to leading "an active life" but an evolutionarily fundamental aspect of "activity," which is needed to provide the brain and its systems of plastic adaptation with the appropriate regulatory input and feedback. PMID:21151782

Kempermann, Gerd; Fabel, Klaus; Ehninger, Dan; Babu, Harish; Leal-Galicia, Perla; Garthe, Alexander; Wolf, Susanne A

2010-12-08

245

Brain Research: the Necessity for Separating Sites, Actions and Functions  

Microsoft Academic Search

Some brain research concentrates solely on the study of sites and actions of brain functions but the writer argues that it is essential for research to investigate the functions also. Educators can offer measures of brain function such as the Structure of Intellect (S O I) and psychologists need information about the characteristics of brain functions if accurate diagnosis is

Mary Meeker

1988-01-01

246

Focus Issue: Memories of Signals Past--Plastic Changes in Nervous System Function  

NSDL National Science Digital Library

Plasticity encompasses the ability of the nervous system to adapt to injury and the ability of the developing and mature brain to change in response to experience. This week's Special Issue of Science focuses on systems-level approaches to understanding cortical plasticity, especially during development. The accompanying Focus Issue of Science's STKE features articles and resources that address issues related to the molecular changes that underlie synaptic plasticity in response to physiological or pathological stimuli.

Elizabeth M. Adler (American Association for the Advancement of Science;Science's STKE REV); Nancy R. Gough (American Association for the Advancement of Science;Science's STKE REV)

2005-11-08

247

On Analysis of Quantifying Learning Creativity Phenomenon Considering Brain Synaptic Plasticity  

Microsoft Academic Search

Generally, Analysis of learning creativity phenomenon is an interesting and challenging issue associated with educational practice. Moreover, that phenomenon is tightly related to main human brain functions (Learning and Memory). So, creative individuals are characterized by their distinct capabilities in performing both brain functions. Additionally, educationalists as well as psychologists, for a long time ago and until recently, have been

Hassan Mustafa

2009-01-01

248

Adaptive plasticity of NMDA receptors and dendritic spines: Implications for enhanced vulnerability of the adolescent brain to alcohol addiction  

Microsoft Academic Search

It is now known that brain development continues into adolescence and early adulthood and is highly influenced by experience-dependent adaptive plasticity during this time. Behaviorally, this period is also characterized by increased novelty seeking and risk-taking. This heightened plasticity appears to be important in shaping behaviors and cognitive processes that contribute to proper development of an adult phenotype. However, increasing

Ezekiel P. Carpenter-Hyland; L. Judson Chandler

2007-01-01

249

Neonatal suprachiasmatic nucleus ablation: absence of functional and morphological plasticity.  

PubMed Central

Neonatal ablation of the suprachiasmatic nucleus in the rat has two important consequences. First, the direct projection from the retina to the suprachiasmatic nucleus fails to develop and no other retinal projection to any hypothalamic nucleus is formed. Second, circadian rhythms in drinking and spontaneous locomotor activity to not appear in these rats when they are tested as adults, and the females exhibit constant vaginal estrus. These observations indicate that the central neural mechanisms responsible for the generation and entrainment of circadian rhythmicity in the rat are not capable of either the functional or morphological plasticity characteristic of other developing neural systems. Images

Mosko, S; Moore, R Y

1978-01-01

250

Boosting Focally-Induced Brain Plasticity by Dopamine  

Microsoft Academic Search

Dopamine (DA) simultaneously produces both excitation and inhi- bition in the human cortex. In order to shed light on the functional significance of these seemingly opposing effects, we administered the DA precursor levodopa (L-dopa) to healthy subjects in conjunc- tion with 2 neuroplasticity-inducing motor cortex stimulation proto- cols. Transcranial direct current stimulation (tDCS) induces cortical excitability enhancement by anodal and

Min-Fang Kuo; Walter Paulus; Michael A. Nitsche

2008-01-01

251

Progesterone Receptors: Form and Function in Brain  

PubMed Central

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

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

2008-01-01

252

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

253

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

PubMed Central

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

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

2012-01-01

254

Distinct Signal Codes Generate Dendritic Cell Functional Plasticity  

PubMed Central

Our adaptive immune system induces distinct responses to different pathogens because of the functional plasticity of dendritic cells (DCs); however, how DCs program unique responses remains unclear. Here, we found that the cytokine thymic stromal lymphopoietin (TSLP) potently transduced a unique T helper type 2 (TH2)–inducing compound signal in DCs. Whereas activation of nuclear factor ?B (predominantly p50) drove DCs to produce OX40L to induce TH2 differentiation, the activation of signal transducer and activator of transcription 6 (STAT6) triggered DCs to secrete chemokines necessary for the recruitment of TH2 cells. In addition, TSLP signaling limited the activation of STAT4 and interferon regulatory factor 8 (IRF-8), which are essential factors for the production of the TH1-polarizing cytokine interleukin-12 (IL-12). By contrast, Toll-like receptor ligands and CD40 ligand did not activate STAT6 in myeloid DCs, but instead increased the abundance of STAT4 and IRF-8 to induce TH1 responses through the production of IL-12. Therefore, we propose that the functional plasticity of DCs relies on elaborate signal codes that are generated by different stimuli.

Arima, Kazuhiko; Watanabe, Norihiko; Hanabuchi, Shino; Chang, Mikyoung; Sun, Shao-Cong; Liu, Yong-Jun

2012-01-01

255

Optogenetic approaches for functional mouse brain mapping  

PubMed Central

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

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

2013-01-01

256

Integrated brain restoration after ischemic stroke--medical management, risk factors, nutrients, and other interventions for managing inflammation and enhancing brain plasticity.  

PubMed

Brain injury from ischemic stroke can be devastating, but full brain restoration is feasible. Time until treatment is critical; rapid rate of injury progression, logistical and personnel constraints on neurological and cardiovascular assessment, limitations of recombinant tissue plasminogen activator (rtPA) for thrombolysis, anticoagulation and antiplatelet interventions, and neuroprotection all affect outcome. Promising acute neuroprotectant measures include albumin, magnesium, and hypothermia. Long-term hyperbaric oxygen therapy (HBOT) is safe and holds great promise. Eicosanoid and cytokine down-regulation by omega-3 nutrients docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) may help quench stroke inflammation. C-reactive protein (CRP), an inflammatory biomarker and stroke-recurrence predictor, responds favorably to krill oil (a phospholipid-DHA/EPA-astaxanthin complex). High homocysteine (Hcy) is a proven predictor of stroke recurrence and responds to folic acid and vitamin B12. Vitamin E may lower recurrence for individuals experiencing high oxidative stress. Citicoline shows promise for acute neuroprotection. Glycerophosphocholine (GPC) is neuroprotective and supports neuroplasticity via nerve growth factor (NGF) receptors. Stem cells have shown promise for neuronal restoration in randomized trials. Endogenous brain stem cells can migrate to an ischemic injury zone; exogenous stem cells once transplanted can migrate (home) to the stroke lesion and provide trophic support for cortical neuroplasticity. The hematopoietic growth factors erythropoietin (EPO) and granulocyte-colony stimulating factor (G-CSF) have shown promise in preliminary trials, with manageable adverse effects. Physical and mental exercises, including constraint-induced movement therapy (CIMT) and interactive learning aids, further support brain restoration following ischemic stroke. Brain plasticity underpins the function-driven brain restoration that can occur following stroke. PMID:19364191

Kidd, Parris M

2009-03-01

257

I. Longitudinal changes in aging brain function.  

PubMed

Changes in brain activity over time were evaluated in a group of older adults in the Baltimore Longitudinal Study of Aging who maintained good physical and cognitive health. Participants underwent PET scans during rest and delayed verbal and figural recognition memory performance at year 1 baseline and at year 9. While memory performance remained stable over the 8 years, longitudinal changes in regional cerebral blood flow were observed within each scan condition. Further analyses revealed distinctive patterns of change related specifically to verbal or figural recognition, as well as longitudinal changes common to all scan conditions. These findings demonstrate that the older brain undergoes functional reorganization with increasing age in healthy, cognitively stable individuals. In view of the stable memory performance, the task-dependent results suggest that age-related changes in brain activity help maintain cognitive function with advancing age. PMID:17184881

Beason-Held, L L; Kraut, M A; Resnick, S M

2006-12-20

258

Functional expression of SGLTs in rat brain.  

PubMed

This work provides evidence of previously unrecognized uptake of glucose via sodium-coupled glucose transporters (SGLTs) in specific regions of the brain. The current understanding of functional glucose utilization in brain is largely based on studies using positron emission tomography (PET) with the glucose tracer 2-deoxy-2-[F-18]fluoro-D-glucose (2-FDG). However, 2-FDG is only a good substrate for facilitated-glucose transporters (GLUTs), not for SGLTs. Thus, glucose accumulation measured by 2-FDG omits the role of SGLTs. We designed and synthesized two high-affinity tracers: one, ?-methyl-4-[F-18]fluoro-4-deoxy-D-glucopyranoside (Me-4FDG), is a highly specific SGLT substrate and not transported by GLUTs; the other one, 4-[F-18]fluoro-4-deoxy-D-glucose (4-FDG), is transported by both SGLTs and GLUTs and will pass through the blood brain barrier (BBB). In vitro Me-4FDG autoradiography was used to map the distribution of uptake by functional SGLTs in brain slices with a comparable result from in vitro 4-FDG autoradiography. Immunohistochemical assays showed that uptake was consistent with the distribution of SGLT protein. Ex vivo 4-FDG autoradiography showed that SGLTs in these areas are functionally active in the normal in vivo brain. The results establish that SGLTs are a normal part of the physiology of specific areas of the brain, including hippocampus, amygdala, hypothalamus, and cerebral cortices. 4-FDG PET imaging also established that this BBB-permeable SGLT tracer now offers a functional imaging approach in humans to assess regulation of SGLT activity in health and disease. PMID:20826762

Yu, Amy S; Hirayama, Bruce A; Timbol, Gerald; Liu, Jie; Basarah, Ernest; Kepe, Vladimir; Satyamurthy, Nagichettiar; Huang, Sung-Cheng; Wright, Ernest M; Barrio, Jorge R

2010-09-08

259

Role of brain allopregnanolone in the plasticity of ?-aminobutyric acid type A receptor in rat brain during pregnancy and after delivery  

PubMed Central

The relation between changes in brain and plasma concentrations of neurosteroids and the function and structure of ?-aminobutyric acid type A (GABAA) receptors in the brain during pregnancy and after delivery was investigated in rats. In contrast with plasma, where all steroids increased in parallel, the kinetics of changes in the cerebrocortical concentrations of progesterone, allopregnanolone (AP), and allotetrahydrodeoxycorticosterone (THDOC) diverged during pregnancy. Progesterone was already maximally increased between days 10 and 15, whereas AP and allotetrahydrodeoxycorticosterone peaked around day 19. The stimulatory effect of muscimol on 36Cl? uptake by cerebrocortical membrane vesicles was decreased on days 15 and 19 of pregnancy and increased 2 days after delivery. Moreover, the expression in cerebral cortex and hippocampus of the mRNA encoding for ?2L GABAA receptor subunit decreased during pregnancy and had returned to control values 2 days after delivery. Also ?1,?2, ?3, ?4, ?1, ?2, ?3, and ?2S mRNAs were measured and failed to change during pregnancy. Subchronic administration of finasteride, a 5?-reductase inhibitor, to pregnant rats reduced the concentrations of AP more in brain than in plasma as well as prevented the decreases in both the stimulatory effect of muscimol on 36Cl? uptake and the decrease of ?2L mRNA observed during pregnancy. These results indicate that the plasticity of GABAA receptors during pregnancy and after delivery is functionally related to fluctuations in endogenous brain concentrations of AP whose rate of synthesis/metabolism appears to differ in the brain, compared with plasma, in pregnant rats.

Concas, A.; Mostallino, M. C.; Porcu, P.; Follesa, P.; Barbaccia, M. L.; Trabucchi, M.; Purdy, R. H.; Grisenti, P.; Biggio, G.

1998-01-01

260

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

261

Classroom Seating and Functional Brain Asymmetry  

ERIC Educational Resources Information Center

|This study examined the relationship between functional brain assymetry, as measured by the characteristic direction of eye movements in response to face-to-face questioning, and sitting on the left or right side of a classroom. Results are congruent with other findings comparing right and left movers. (Author/BJG)|

Gur, Raquel E.; And Others

1975-01-01

262

Superbinding in integrative brain function and memory  

Microsoft Academic Search

A proposal related to the superbinding of the activity of neural populations is outlined. Based on the observation of EEG-oscillations, this proposal aims to replace the Sherrington's single neuron doctrine for interpretation of the mechanisms of complex percepts and integrative brain function.

E. Basar; M. Ozgoren; S. Karakas

2001-01-01

263

Early Experience Alters Brain Function and Structure  

Microsoft Academic Search

Objective. To investigate the effects of early experience on brain function and structure. Methods. A randomized clinical trial tested the neu- rodevelopmental effectiveness of the Newborn Individ- ualized Developmental Care and Assessment Program (NIDCAP). Thirty preterm infants, 28 to 33 weeks' ges- tational age (GA) at birth and free of known develop- mental risk factors, participated in the trial. NIDCAP

Frank H. Duffy; Gloria B. McAnulty; Michael J. Rivkin; Sridhar Vajapeyam; Robert V. Mulkern; Simon K. Warfield; Petra S. Huppi; Samantha C. Butler; Nikk Conneman; Christine Fischer; Eric C. Eichenwald

2004-01-01

264

Metabolism and functions of glutathione in brain  

Microsoft Academic Search

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

Ralf Dringen

2000-01-01

265

Experience--a double edged sword for restorative neural plasticity after brain damage.  

PubMed

During the time period following damage, the brain undergoes widespread reorganizational processes. Manipulations of behavioral experience can be potent therapeutic interventions for shaping this reorganization and enhancing long-term functional outcome. Recovery of function is a major concern for survivors of central nervous system damage and management of post-injury rehabilitation is increasingly becoming a topic of chief importance. Animal research, the focus of this review, suggests that, in the absence of behavioral manipulations, the brain is unlikely to realize its full potential for supporting function. However, experiences also have the capacity to be maladaptive for brain and behavioral function. From a treatment perspective, it may be unwise to adopt the canon of "first, do no harm" because maladaptive experiences include behaviors that individuals learn to do on their own. A better understanding of how behavioral experience interacts with brain reorganization could result in rehabilitative therapies, individually tailored and optimized for functional outcome. PMID:19718283

Allred, Rachel P; Jones, Theresa A

2008-03-01

266

See the brain at work: intraoperative laser Doppler functional brain imaging  

NASA Astrophysics Data System (ADS)

During open brain surgery we acquire perfusion images non-invasively using laser Doppler imaging. The regions of brain activity show a distinct signal in response to stimulation providing intraoperative functional brain maps of remarkably strong contrast.

Martin-Williams, E. J.; Raabe, A.; van de Ville, D.; Leutenegger, M.; Szelényi, A.; Hattingen, E.; Gerlach, R.; Seifert, V.; Hauger, C.; Lopez, A.; Leitgeb, R.; Unser, M.; Lasser, T.

2009-07-01

267

Plasticity and Reorganization During Language Development in Children with Early Brain Injury  

Microsoft Academic Search

Although some studies have reported subtle language deficits following early focal brain lesions (EFBL), most studies find no evidence for differential language outcomes as a function of lesion side or lesion type in children with congenital injuries to one side of the brain. However, recent prospective studies of the first stages of language development in English-speaking children with EFBL have

S. Vicari; A. Albertoni; A. M. Chilosi; P. Cipriani; G. Cioni; E. Bates

2000-01-01

268

Neuromagnetic integrated methods tracking human brain mechanisms of sensorimotor areas ‘plastic’ reorganisation  

Microsoft Academic Search

The potential for reorganization in the adult brain has been largely underestimated in the past and we are just beginning to understand the organisational principles involved in functional recovery. A bulk of experimental evidences have been accumulated in support of the hypothesis that neuronal aggregates adjacent to a lesion in the cortical brain areas can be progressively vicarious to the

P. M Rossini; F Pauri

2000-01-01

269

Brain function, nonlinear coupling, and neuronal transients.  

PubMed

The brain can be regarded as an ensemble of connected dynamical systems and as such conforms to some simple principles relating the inputs and outputs of its constituent parts. The ensuing implications, for the way we think about, and measure, neuronal interactions, can be quite profound. These range from 1) implications for which aspects of neuronal activity are important to measure and how to characterize coupling among neuronal populations; 2) implication for understanding the emergence of dynamic receptive fields and functionally specialized brain architectures; and 3) teleological implications pertaining to the genesis of dynamic instability and complexity, which is necessary for adaptive self-organization. This review focuses on the first set of implications by looking at neuronal interactions, coupling, and implicit neuronal codes from a dynamical perspective. By considering the brain in this light, one can show that a sufficient description of neuronal activity must comprise activity at the current time and its recent history. This history constitutes a neuronal transient. Such transients represent an essential metric of neuronal interactions and, implicitly, a code employed in the functional integration of brain systems. The nature of transients, expressed conjointly in different neuronal populations, reflects the underlying coupling among brain systems. A complete description of this coupling, or effective connectivity, can be expressed in terms of generalized convolution kernels (Volterra kernels) that embody high-order or nonlinear interactions. This coupling may be synchronous, and possibly oscillatory, or asynchronous. A critical distinction between synchronous and asynchronous coupling is that the former is essentially linear and the latter is nonlinear. The nonlinear nature of asynchronous coupling enables the rich, context-sensitive interactions that characterize real brain dynamics, suggesting that it plays an important role in functional integration. PMID:11597100

Friston, K J

2001-10-01

270

Different Plasticity Patterns of Language Function in Children With Perinatal and Childhood Stroke.  

PubMed

Plasticity of language function after brain damage can depend on maturation of the brain. Children with left-hemisphere perinatal (n = 7) or childhood stroke (n = 5) and 12 controls were investigated using functional magnetic resonance imaging. The verb generation and the sentence comprehension tasks were employed to activate the expressive and receptive language areas, respectively. Weighted laterality indices were calculated and correlated with results assessed by neuropsychological test battery. Compared to controls, children with childhood stroke showed significantly lower mean scores for the expressive (P < .05) and receptive (P = .05) language tests. On functional magnetic resonance imaging they showed left-side cortical activation, as did controls. Perinatal stroke patients showed atypical right-side or bilateral language lateralization during both tasks. Negative correlation for stroke patients was found between scores for expressive language tests and laterality index during the verb generation task. (Re)organization of language function differs in children with perinatal and childhood stroke and correlates with neurocognitive performance. PMID:23748202

Ilves, Pilvi; Tomberg, Tiiu; Kepler, Joosep; Laugesaar, Rael; Kaldoja, Mari-Liis; Kepler, Kalle; Kolk, Anneli

2013-06-17

271

Functional Dissociation of Ongoing Oscillatory Brain States  

PubMed Central

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

Salari, Neda; Buchel, Christian; Rose, Michael

2012-01-01

272

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

273

Electroencephalographic imaging of higher brain function.  

PubMed Central

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

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

1999-01-01

274

Synaptic Plasticity, Neurogenesis, and Functional Recovery after Spinal Cord Injury  

PubMed Central

Spinal cord injury research has greatly expanded in recent years, but our understanding of the mechanisms that underlie the functional recovery that can occur over the weeks and months following the initial injury, is far from complete. To grasp the scope of the problem, it is important to begin by defining the sensorimotor pathways that might be involved by a spinal injury. This is done in the rodent and nonhuman primate, which are two of the most commonly used animal models in basic and translational spinal injury research. Many of the better known experimentally induced models are then reviewed in terms of the pathways they involve and the reorganization and recovery that have been shown to follow. The better understood neuronal mechanisms mediating such post-injury plasticity, including dendritic spine growth and axonal sprouting, are then examined.

Darian-Smith, Corinna

2010-01-01

275

Structural and functional neuroimaging studies of the suicidal brain  

Microsoft Academic Search

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

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

2011-01-01

276

Nicotine increases brain functional network efficiency.  

PubMed

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

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

2012-07-14

277

Large-scale functional brain networks in human non-rapid eye movement sleep: insights from combined electroencephalographic/functional magnetic resonance imaging studies.  

PubMed

This paper reviews the existing body of knowledge on the neural correlates of spontaneous oscillations, functional connectivity and brain plasticity in human non-rapid eye movement (NREM) sleep. The first section reviews the evidence that specific sleep events as slow waves and spindles are associated with transient increases in regional brain activity. The second section describes the changes in functional connectivity during NREM sleep, with a particular focus on changes within a low-frequency, large-scale functional brain network. The third section will discuss the possibility that spontaneous oscillations and differential functional connectivity are related to brain plasticity and systems consolidation, with a particular focus on motor skill acquisition. Implications for the mode of information processing per sleep stage and future experimental studies are discussed. PMID:21893524

Spoormaker, Victor I; Czisch, Michael; Maquet, Pierre; Jäncke, Lutz

2011-10-13

278

Robust transient dynamics and brain functions.  

PubMed

In the last few decades several concepts of dynamical systems theory (DST) have guided psychologists, cognitive scientists, and neuroscientists to rethink about sensory motor behavior and embodied cognition. A critical step in the progress of DST application to the brain (supported by modern methods of brain imaging and multi-electrode recording techniques) has been the transfer of its initial success in motor behavior to mental function, i.e., perception, emotion, and cognition. Open questions from research in genetics, ecology, brain sciences, etc., have changed DST itself and lead to the discovery of a new dynamical phenomenon, i.e., reproducible and robust transients that are at the same time sensitive to informational signals. The goal of this review is to describe a new mathematical framework - heteroclinic sequential dynamics - to understand self-organized activity in the brain that can explain certain aspects of robust itinerant behavior. Specifically, we discuss a hierarchy of coarse-grain models of mental dynamics in the form of kinetic equations of modes. These modes compete for resources at three levels: (i) within the same modality, (ii) among different modalities from the same family (like perception), and (iii) among modalities from different families (like emotion and cognition). The analysis of the conditions for robustness, i.e., the structural stability of transient (sequential) dynamics, give us the possibility to explain phenomena like the finite capacity of our sequential working memory - a vital cognitive function -, and to find specific dynamical signatures - different kinds of instabilities - of several brain functions and mental diseases. PMID:21716642

Rabinovich, Mikhail I; Varona, Pablo

2011-06-13

279

Robust Transient Dynamics and Brain Functions  

PubMed Central

In the last few decades several concepts of dynamical systems theory (DST) have guided psychologists, cognitive scientists, and neuroscientists to rethink about sensory motor behavior and embodied cognition. A critical step in the progress of DST application to the brain (supported by modern methods of brain imaging and multi-electrode recording techniques) has been the transfer of its initial success in motor behavior to mental function, i.e., perception, emotion, and cognition. Open questions from research in genetics, ecology, brain sciences, etc., have changed DST itself and lead to the discovery of a new dynamical phenomenon, i.e., reproducible and robust transients that are at the same time sensitive to informational signals. The goal of this review is to describe a new mathematical framework – heteroclinic sequential dynamics – to understand self-organized activity in the brain that can explain certain aspects of robust itinerant behavior. Specifically, we discuss a hierarchy of coarse-grain models of mental dynamics in the form of kinetic equations of modes. These modes compete for resources at three levels: (i) within the same modality, (ii) among different modalities from the same family (like perception), and (iii) among modalities from different families (like emotion and cognition). The analysis of the conditions for robustness, i.e., the structural stability of transient (sequential) dynamics, give us the possibility to explain phenomena like the finite capacity of our sequential working memory – a vital cognitive function –, and to find specific dynamical signatures – different kinds of instabilities – of several brain functions and mental diseases.

Rabinovich, Mikhail I.; Varona, Pablo

2011-01-01

280

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

281

Using non-invasive brain stimulation to augment motor training-induced plasticity  

Microsoft Academic Search

Therapies for motor recovery after stroke or traumatic brain injury are still not satisfactory. To date the best approach seems to be the intensive physical therapy. However the results are limited and functional gains are often minimal. The goal of motor training is to minimize functional disability and optimize functional motor recovery. This is thought to be achieved by modulation

Nadia Bolognini; Alvaro Pascual-Leone; Felipe Fregni

2009-01-01

282

Functional connectivity hubs in the human brain.  

PubMed

Brain networks appear to have few and well localized regions with high functional connectivity density (hubs) for fast integration of neural processing, and their dysfunction could contribute to neuropsychiatric diseases. However the variability in the distribution of these brain hubs is unknown due in part to the overwhelming computational demands associated to their localization. Recently we developed a fast algorithm to map the local functional connectivity density (lFCD). Here we extend our method to map the global density (gFDC) taking advantage of parallel computing. We mapped the gFCD in the brain of 1031 subjects from the 1000 Functional Connectomes project and show that the strongest hubs are located in regions of the default mode network (DMN) and in sensory cortices, whereas subcortical regions exhibited the weakest hubs. The strongest hubs were consistently located in ventral precuneus/cingulate gyrus (previously identified by other analytical methods including lFCD) and in primary visual cortex (BA 17/18), which highlights their centrality to resting connectivity networks. In contrast and after rescaling, hubs in prefrontal regions had lower gFCD than lFCD, which suggests that their local functional connectivity (as opposed to long-range connectivity) prevails in the resting state. The power scaling of the probability distribution of gFCD hubs (as for lFCD) was consistent across research centers further corroborating the "scale-free" topology of brain networks. Within and between-subject variability for gFCD were twice than that for lFCD (20% vs. 12% and 84% vs. 34%, respectively) suggesting that gFCD is more sensitive to individual differences in functional connectivity. PMID:21609769

Tomasi, Dardo; Volkow, Nora D

2011-05-14

283

In vivo assessment of use-dependent brain plasticity--beyond the "one trick pony" imaging strategy.  

PubMed

This article has been written as a comment to Dr Thomas and Dr Baker's article "Teaching an adult brain new tricks: A critical review of evidence for training-dependent structural plasticity in humans". We deliberately expand on the key question about the biological substrates underlying use-dependent brain plasticity rather than reiterating the authors' main points of criticism already addressed in more general way by previous publications in the field. The focus here is on the following main issues: i) controversial brain plasticity findings in voxel-based morphometry studies are partially due to the strong dependency of the widely used T1-weighted imaging protocol on varying magnetic resonance contrast contributions; ii) novel concepts in statistical analysis allow one to directly infer topological specificity of structural brain changes associated with plasticity. We conclude that iii) voxel-based quantification of relaxometry derived parameter maps could provide a new perspective on use-dependent plasticity by characterisation of brain tissue property changes beyond the estimation of volume and cortical thickness changes. In the relevant sections we respond to the concerns raised by Dr Thomas and Dr Baker from the perspective of the proposed data acquisition and analysis strategy. PMID:22960085

Draganski, Bogdan; Kherif, Ferath

2012-08-28

284

Rehabilitation of brain damage: Brain plasticity and principles of guided recovery  

Microsoft Academic Search

Rehabilitation of the damaged brain can foster reconnection of damaged neural circuits; Hebbian learning mechanisms play an important part in this. The authors propose a triage of post-lesion states, depending on the loss of connectivity in particular circuits. A small loss of connectivity will tend to lead to autonomous recovery, whereas a major loss of connectivity will lead to permanent

J. M. J. Murre; I. H. Robertson

1999-01-01

285

Rehabilitation of Brain Damage: Brain Plasticity and Principles of Guided Recovery  

Microsoft Academic Search

Rehabilitation of the damaged brain can foster reconnection of damaged neural circuits; Hebbian learning mechanisms play an important part in this. The authors propose a triage of post-lesion states, depending on the loss of connectivity in particular circuits. A small loss of connectivity will tend to lead to autonomous recovery, whereas a major loss of connectivity will lead to permanent

Ian H. Robertson; Jaap M. J. Murre

1999-01-01

286

Using knowledge of development to promote recovery of function after brain damage.  

PubMed

Knowledge of normal development of brain-behavior relations plays an important role in understanding how the plasticity of the nervous system can be used to promote recovery of function following brain damage. Aspects of the other articles in this issue are used in justification of the value of such developmental knowledge. Also, the development of amblyopia and its remediation in adulthood is discussed as a model for developing other techniques for ensuring recovery of function after stroke. Although the articles in this issue establish an excellent context for improving actual recovery of function (rather than compensation for deficits), much still needs to be discovered about how we can use developmental knowledge, along with knowledge of the plasticity of the nervous system, to improve remediation techniques. PMID:22415922

Michel, George F

2012-04-01

287

Stimulation of muscarinic receptors mimics experience-dependent plasticity in the honey bee brain.  

PubMed

Honey bees begin life working in the hive. At approximately 3 weeks of age, they shift to visiting flowers to forage for pollen and nectar. Foraging is a complex task associated with enlargement of the mushroom bodies, a brain region important in insects for certain forms of learning and memory. We report here that foraging bees had a larger volume of mushroom body neuropil than did age-matched bees confined to the hive. This result indicates that direct experience of the world outside the hive causes mushroom body neuropil growth in bees. We also show that oral treatment of caged bees with pilocarpine, a muscarinic agonist, induced an increase in the volume of the neuropil similar to that seen after a week of foraging experience. Effects of pilocarpine were blocked by scopolamine, a muscarinic antagonist. Our results suggest that signaling in cholinergic pathways couples experience to structural brain plasticity. PMID:16373504

Ismail, Nyla; Robinson, Gene E; Fahrbach, Susan E

2005-12-22

288

Lamin B1 maintains the functional plasticity of nucleoli  

PubMed Central

Summary The dynamic ability of genomes to interact with discrete nuclear compartments appears to be essential for chromatin function. However, the extent to which structural nuclear proteins contribute to this level of organization is largely unresolved. To test the links between structure and function, we evaluated how nuclear lamins contribute to the organization of a major functional compartment, the nucleolus. HeLa cells with compromised expression of the genes encoding lamins were analyzed using high-resolution imaging and pull-down assays. When lamin B1 expression was depleted, inhibition of RNA synthesis correlated with complex structural changes within the nucleolar active centers until, eventually, the nucleoli were dispersed completely. With normal lamin expression, the nucleoli were highly plastic, with dramatic and freely reversible structural changes correlating with the demand for ribosome biogenesis. Preservation of the nucleolar compartment throughout these structural transitions is shown to be linked to lamin B1 expression, with the lamin B1 protein interacting with the major nucleolar protein nucleophosmin/B23.

Martin, Catherine; Chen, Songbi; Maya-Mendoza, Apolinar; Lovric, Josip; Sims, Paul F. G.; Jackson, Dean A.

2009-01-01

289

Dynamic geometry, brain function modeling, and consciousness.  

PubMed

Pellionisz and Llinás proposed, years ago, a geometric interpretation towards understanding brain function. This interpretation assumes that the relation between the brain and the external world is determined by the ability of the central nervous system (CNS) to construct an internal model of the external world using an interactive geometrical relationship between sensory and motor expression. This approach opened new vistas not only in brain research but also in understanding the foundations of geometry itself. The approach named tensor network theory is sufficiently rich to allow specific computational modeling and addressed the issue of prediction, based on Taylor series expansion properties of the system, at the neuronal level, as a basic property of brain function. It was actually proposed that the evolutionary realm is the backbone for the development of an internal functional space that, while being purely representational, can interact successfully with the totally different world of the so-called "external reality". Now if the internal space or functional space is endowed with stochastic metric tensor properties, then there will be a dynamic correspondence between events in the external world and their specification in the internal space. We shall call this dynamic geometry since the minimal time resolution of the brain (10-15 ms), associated with 40 Hz oscillations of neurons and their network dynamics, is considered to be responsible for recognizing external events and generating the concept of simultaneity. The stochastic metric tensor in dynamic geometry can be written as five-dimensional space-time where the fifth dimension is a probability space as well as a metric space. This extra dimension is considered an imbedded degree of freedom. It is worth noticing that the above-mentioned 40 Hz oscillation is present both in awake and dream states where the central difference is the inability of phase resetting in the latter. This framework of dynamic geometry makes it possible to distinguish one individual from another. In this paper we shall investigate the role of dynamic geometry in brain function modeling and the neuronal basis of consciousness. PMID:18166391

Roy, Sisir; Llinás, Rodolfo

2008-01-01

290

BDNF but not NT-4 is required for normal flexion reflex plasticity and function  

PubMed Central

Neurotrophins can directly modulate the function of diverse types of central nervous system synapses. Brain-derived neurotrophic factor (BDNF) might be released by nociceptors onto spinal neurons and mediate central sensitization associated with chronic pain. We have studied the role of BDNF and neurotrophin-4 (NT-4), both ligands of the trkB tyrosine kinase receptor, in synaptic transmission and reflex plasticity in the mouse spinal cord. We used an in vitro spinal cord preparation to measure monosynaptic and polysynaptic reflexes evoked by primary afferents in BDNF- and NT-4-deficient mice. In situ hybridization studies show that both these neurotrophins are synthesized by sensory neurons, and NT-4, but not BDNF, also is expressed by spinal neurons. BDNF null mutants display selective deficits in the ventral root potential (VRP) evoked by stimulating nociceptive primary afferents whereas the non-nociceptive portion of the VRP remained unaltered. In addition, activity-dependent plasticity of the VRP evoked by repetitive (1 Hz) stimulation of nociceptive primary afferents (termed wind-up) was substantially reduced in BDNF-deficient mice. This plasticity also was reduced in a reversible manner by the protein kinase inhibitor K252a. Although the trkB ligand NT-4 is normally present, reflex properties in NT-4 null mutant mice were normal. Pharmacological studies also indicated that spinal N-methyl-d-aspartate receptor function was unaltered in BDNF-deficient mice. Using immunocytochemistry for markers of nociceptive neurons we found no evidence that their number or connectivity was substantially altered in BDNF-deficient mice. Our data therefore are consistent with a direct role for presynaptic BDNF release from sensory neurons in the modulation of pain-related neurotransmission.

Heppenstall, Paul A.; Lewin, Gary R.

2001-01-01

291

Computerized brain atlas in functional neurosurgery.  

PubMed

Computerized brain atlas is a new application area in the practical use of stereotactic neurosurgery. Our approach provides a solution for the straightforward definition of a coordinate system (CA-CP), localization of the selected target point, trepanation points and trajectory transformation of the stereotactic electrode or canula for functional neurosurgery. These problems were solved by comparison of CT, MR and the Schaltenbrand-Wahren atlas. Our original software package integrates all modalities into one system. PMID:9711740

Sramka, M; Ruzicky, E; Novotny, M

1997-01-01

292

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.

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

2009-01-01

293

Subchronic alpha-linolenic acid treatment enhances brain plasticity and exerts an antidepressant effect: a versatile potential therapy for stroke.  

PubMed

Omega-3 polyunsaturated fatty acids are known to have therapeutic potential in several neurological and psychiatric disorders. However, the molecular mechanisms of action underlying these effects are not well elucidated. We previously showed that alpha-linolenic acid (ALA) reduced ischemic brain damage after a single treatment. To follow-up this finding, we investigated whether subchronic ALA treatment promoted neuronal plasticity. Three sequential injections with a neuroprotective dose of ALA increased neurogenesis and expression of key proteins involved in synaptic functions, namely, synaptophysin-1, VAMP-2, and SNAP-25, as well as proteins supporting glutamatergic neurotransmission, namely, V-GLUT1 and V-GLUT2. These effects were correlated with an increase in brain-derived neurotrophic factor (BDNF) protein levels, both in vitro using neural stem cells and hippocampal cultures and in vivo, after subchronic ALA treatment. Given that BDNF has antidepressant activity, this led us to test whether subchronic ALA treatment could produce antidepressant-like behavior. ALA-treated mice had significantly reduced measures of depressive-like behavior compared with vehicle-treated animals, suggesting another aspect of ALA treatment that could stimulate functional stroke recovery by potentially combining acute neuroprotection with long-term repair/compensatory plasticity. Indeed, three sequential injections of ALA enhanced protection, either as a pretreatment, wherein it reduced post-ischemic infarct volume 24 h after a 1-hour occlusion of the middle cerebral artery or as post-treatment therapy, wherein it augmented animal survival rates by threefold 10 days after ischemia. PMID:19641487

Blondeau, Nicolas; Nguemeni, Carine; Debruyne, David N; Piens, Marie; Wu, Xuan; Pan, Hongna; Hu, XianZhang; Gandin, Carine; Lipsky, Robert H; Plumier, Jean-Christophe; Marini, Ann M; Heurteaux, Catherine

2009-07-29

294

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

PubMed

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

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

2013-04-03

295

Fish & Chips: Functional Genomics of Social Plasticity in an African Cichlid Fish  

PubMed Central

Behaviour and physiology are regulated by both environment and social context. A central goal in the study of the social control of behaviour is to determine the underlying physiological, cellular and molecular mechanisms in the brain. The African cichlid fish Astatotilapia burtoni has long been used as a model system to study how social interactions regulate neural and behavioural plasticity. In this species, males are either socially dominant and reproductively active or subordinate and reproductively suppressed. This phenotypic difference is reversible. Using an integrative approach that combines quantitative behavioural measurements, functional genomics and bioinformatic analyses, we examine neural gene expression in dominant and subordinate males as well as brooding females. We confirm the role of numerous candidate genes that are part of neuroendocrine pathways and show that specific co-regulated gene sets (modules), as well as specific functional Gene Ontology categories, are significantly associated with dominance or reproductive state. Finally, even though the dominant and subordinate phenotypes are robustly defined, we find a surprisingly high degree of individual variation in the transcript levels of the very genes that are differentially regulated between these phenotypes. Our results demonstrate the molecular complexity in the brain underlying social behaviour, identify novel targets for future studies, validate many candidate genes, and exploit individual variation in order to gain biological insights.

Renn, Susan C.P.; Aubin-Horth, Nadia; Hofmann, Hans A.

2013-01-01

296

Cerebral aging: integration of brain and behavioral models of cognitive function  

PubMed Central

There are substantial declines in behavioral measures of cognitive function with age, including decreased function of executive processes and long-term memory. There is also evidence that, with age, there is a decrease in brain volume, particularly in the frontal cortex. When young and older adults perform cognitive tasks that depend heavily on frontal function, neuroimaging evidence indicates that older adults recruit additional brain regions in order to perform the tasks. This additional neural recruitment is termed “dedifferentiation,” and can take multiple forms. This recruitment of additional neural tissue with age to perform cognitive tasks was not reflected in the behavioral literature, and suggests that there is more plasticity in the ability to organize brain function than was previously suspected. We review both behavioral and neuroscience perspectives on cognitive aging, and then connect the findings in the two areas. From this integration, we suggest important unresolved questions and directions for future research.

Park, Denise C.; Polk, Thad A.; Mikels, Joseph A.; Taylor, Stephan F.; Marshuetz, Christy

2001-01-01

297

New Directions in Brain Imaging Research in Functional Gastrointestinal Disorders  

Microsoft Academic Search

Functional brain imaging has greatly enhanced the ability to investigate brain-gut interactions and to assess the central nervous system role on visceral pain perception. The results of studies using brain imaging in irritable bowel syndrome (IBS) have demonstrated differences in brain activation between patients with IBS and healthy controls. In addition, the more recent studies are starting to shed light

Yehuda Ringel

2006-01-01

298

Reconciling Stable Asymmetry with Recovery of Function: An Adaptive Systems Perspective on Functional Plasticity.  

ERIC Educational Resources Information Center

This commentary, written in response to Witelson's work (1987), examines alternative ways of determining how the developmentally stable functional asymmetry (hemispheric specialization) observed in neurologically intact children can be reconciled with the dramatic recovery of function often displayed following unilateral brain damage. (PCB)

Bullock, Daniel; And Others

1987-01-01

299

Brain plasticity and pathology in psychiatric disease: sites of action for potential therapy  

Microsoft Academic Search

Recent advances have been made in understanding the changes in neuronal plasticity in psychiatric disease at the molecular level (changes in neurotransmission, long-term potentiation, long-term depression, glutamate receptors, synaptic strength and neurotrophic support) and the systems level (changes in hippocampal, frontal and amygdala function in health and disease and the impact of stress on the hippocampal\\/frontal axis), as well as

Michael Spedding; Isabelle Neau; Laszlo Harsing

2003-01-01

300

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

PubMed Central

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 of the injury. Exercise has a healing ability but its action on proteasome function is not understood. Male Sprague-Dawley adult rats (n=19) were performed mild brain fluid percussion injury (FPI) prior to exercise. Animals were assigned to four groups: sedentary (Sed) or exercise (Exc) with sham surgery (Sham) or FPI: Sham/Sed, Sham/Exc, FPI/Sed, FPI/Exc. Animals were sacrificed after 14 days of treatment. FPI elevated levels of carbonyl (160.1±9.6% SEM, p<0.01) and reduced synapsin I levels (58.3±4.3% SEM, p<0.01) in the ipsilateral side of caudal cerebral cortex (FPI/Sed compared to Sham/Sed controls), and it appears that increased levels of carbonyls were associated with increased chymotripsin like activity. These results seem to indicate that proteasome function may be associated with levels of oxidative stress, and that these events may contribute to the action of exercise on synaptic plasticity. Interestingly, exercise attenuated changes in carbonyls, proteasome activity, and synapsin I following FPI, which may indicate an action of exercise on the molecular substrates that control protein turnover following brain trauma. Levels of the regulatory transcription factor of proteasome, Zif 268 were reduced by exercise in Sham and FPI animals and changed in proportion with proteasome activity/content. The overall results indicate that the action of exercise interfaces with that of brain injury on molecular systems involved with protein fate and function, which may be significant for synaptic plasticity.

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

2009-01-01

301

Effects of adverse experiences for brain structure and function  

Microsoft Academic Search

Studies of the hippocampus as a target of stress and stress hormones have revealed a considerable degree of structural plasticity in the adult brain. Repeated stress causes shortening and debranching of dendrites in the CA3 region of the hippocampus and suppresses neurogenesis of dentate gyrus granule neurons. Both forms of structural remodeling of the hippocampus appear to be reversible and

Bruce S. McEwen

2000-01-01

302

Fast Optical Imaging of Human Brain Function  

PubMed Central

Great advancements in brain imaging during the last few decades have opened a large number of new possibilities for neuroscientists. The most dominant methodologies (electrophysiological and magnetic resonance-based methods) emphasize temporal and spatial information, respectively. However, theorizing about brain function has recently emphasized the importance of rapid (within 100?ms or so) interactions between different elements of complex neuronal networks. Fast optical imaging, and in particular the event-related optical signal (EROS, a technology that has emerged over the last 15?years) may provide descriptions of localized (to sub-cm level) brain activity with a temporal resolution of less than 100?ms. The main limitations of EROS are its limited penetration, which allows us to image cortical structures not deeper than 3?cm from the surface of the head, and its low signal-to-noise ratio. Advantages include the fact that EROS is compatible with most other imaging methods, including electrophysiological, magnetic resonance, and trans-cranial magnetic stimulation techniques, with which can be recorded concurrently. In this paper we present a summary of the research that has been conducted so far on fast optical imaging, including evidence for the possibility of recording neuronal signals with this method, the properties of the signals, and various examples of applications to the study of human cognitive neuroscience. Extant issues, controversies, and possible future developments are also discussed.

Gratton, Gabriele; Fabiani, Monica

2010-01-01

303

Exercise is brain food: the effects of physical activity on cognitive function.  

PubMed

This commentary reviews selected biomedical and clinical research examining the relationship between physical exercise and cognitive function especially in youth with disability. Youth with physical disability may not benefit from the effects of exercise on cardiovascular fitness and brain health since they are less active than their non-disabled peers. In animal models, physical activity enhances memory and learning, promotes neurogenesis and protects the nervous system from injury and neurodegenerative disease. Neurotrophins, endogenous proteins that support brain plasticity likely mediate the beneficial effects of exercise on the brain. In clinical studies, exercise increases brain volume in areas implicated in executive processing, improves cognition in children with cerebral palsy and enhances phonemic skill in school children with reading difficulty. Studies examining the intensity of exercise required to optimize neurotrophins suggest that moderation is important. Sustained increases in neurotrophin levels occur with prolonged low intensity exercise, while higher intensity exercise, in a rat model of brain injury, elevates the stress hormone, corticosterone. Clearly, moderate physical activity is important for youth whose brains are highly plastic and perhaps even more critical for young people with physical disability. PMID:18781504

Ploughman, Michelle

2008-07-01

304

Immunosenescence and macrophage functional plasticity: dysregulation of macrophage function by age-associated microenvironmental changes  

PubMed Central

Summary The macrophage lineage displays extreme functional and phenotypic heterogeneity which appears to due in large part to the ability of macrophages to functionally adapt to changes in their tissue microenvironment. This functional plasticity plays a critical role in their ability to respond to tissue damage and/or infection and to contribute to clearance of damaged tissue and invading microorganisms, to contribute to recruitment of the adaptive immune system, and to contribute to resolution of the wound and of the immune response. Evidence has accumulated that environmental influences, such as stromal function and imbalances in hormones and cytokines, contribute significantly to the dysfunction of the adaptive immune system. The innate immune sytem also appears to be dysfunctional in aged animals and humans. Herein, the hypothesis is presented and discussed that the observed age-associated “dysfunction” of macrophages is the result of their functional adaptation to the age-associated changes in tissue environments. The resultant loss of orchestration of the manifold functional capabilities of macrophages would undermine the efficacy of both the innate and adaptive immune systems. If the macrophages maintain functional plasticity during this dysregulation, they would be a prime target of cytokine therapy that could enhance both innate and adaptive immune systems.

Stout, Robert D.; Suttles, Jill

2005-01-01

305

Split My Brain  

NSDL National Science Digital Library

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

Omarzu, Julia

2004-10-01

306

Videogame training strategy-induced change in brain function during a complex visuomotor task.  

PubMed

Although changes in brain function induced by cognitive training have been examined, functional plasticity associated with specific training strategies is still relatively unexplored. In this study, we examined changes in brain function during a complex visuomotor task following training using the Space Fortress video game. To assess brain function, participants completed functional magnetic resonance imaging (fMRI) before and after 30 h of training with one of two training regimens: Hybrid Variable-Priority Training (HVT), with a focus on improving specific skills and managing task priority, or Full Emphasis Training (FET), in which participants simply practiced the game to obtain the highest overall score. Control participants received only 6 h of FET. Compared to FET, HVT learners reached higher performance on the game and showed less brain activation in areas related to visuo-spatial attention and goal-directed movement after training. Compared to the control group, HVT exhibited less brain activation in right dorsolateral prefrontal cortex (DLPFC), coupled with greater performance improvement. Region-of-interest analysis revealed that the reduction in brain activation was correlated with improved performance on the task. This study sheds light on the neurobiological mechanisms of improved learning from directed training (HVT) over non-directed training (FET), which is related to visuo-spatial attention and goal-directed motor planning, while separating the practice-based benefit, which is related to executive control and rule management. PMID:22504276

Lee, Hyunkyu; Voss, Michelle W; Prakash, Ruchika Shaurya; Boot, Walter R; Vo, Loan T K; Basak, Chandramallika; Vanpatter, Matt; Gratton, Gabriele; Fabiani, Monica; Kramer, Arthur F

2012-04-06

307

The role of neural cell adhesion molecules in plasticity and repair  

Microsoft Academic Search

Repair and functional recovery after brain injury critically depends on structural and functional plasticity of preserved neuronal networks. A striking feature of brain structures where tissue reorganization and plasticity occur is a strong expression of the polysialylated neural cell adhesion molecule (PSA-NCAM). An important role of this molecule in various aspects of neuronal and synaptic plasticity has been revealed by

J. Z Kiss; E Troncoso; Z Djebbara; L Vutskits; D Muller

2001-01-01

308

Writing for emotion management: Integrating brain functioning and subjective experience  

Microsoft Academic Search

The brain's emotion processing system is briefly discussed as a model for understanding the emotional benefits of expressive writing. The act of writing integrates both brain functioning and subjective experience.

Beth Jacobs

2010-01-01

309

New scenarios for neuronal structural plasticity in non-neurogenic brain parenchyma: the case of cortical layer II immature neurons.  

PubMed

The mammalian central nervous system, due to its interaction with the environment, must be endowed with plasticity. Conversely, the nervous tissue must be substantially static to ensure connectional invariability. Structural plasticity can be viewed as a compromise between these requirements. In adult mammals, brain structural plasticity is strongly reduced with respect to other animal groups in the phylogenetic tree. It persists under different forms, which mainly consist of remodeling of neuronal shape and connectivity, and, to a lesser extent, the production of new neurons. Adult neurogenesis is mainly restricted within two neurogenic niches, yet some gliogenic and neurogenic processes also occur in the so-called non-neurogenic tissue, starting from parenchymal progenitors. In this review we focus on a population of immature, non-newly generated neurons in layer II of the cerebral cortex, which were previously thought to be newly generated since they heavily express the polysialylated form of the neural cell adhesion molecule and doublecortin. These unusual neurons exhibit characteristics defining an additional type of structural plasticity, different from either synaptic plasticity or adult neurogenesis. Evidences concerning their morphology, antigenic features, ultrastructure, phenotype, origin, fate, and reaction to different kind of stimulations are gathered and analyzed. Their possible role is discussed in the context of an enriched complexity and heterogeneity of mammalian brain structural plasticity. PMID:22609484

Bonfanti, Luca; Nacher, Juan

2012-05-17

310

Reestablishing Speech Understanding through Musical Ear Training after Cochlear Implantation A Study of the Potential Cortical Plasticity in the Brain  

Microsoft Academic Search

Cochlear implants (CIs) provide impressive speech perception for persons with se- vere hearing loss, but many CI recipients fail in perceiving speech prosody and music. Successful rehabilitation depends on cortical plasticity in the brain and postoperative measures. The present study evaluates the behavioral and neurologic effects of musical ear training on CI users' speech and music perception. The goal is

Bjørn Petersen; Malene V. Mortensen; Albert Gjedde; Peter Vuusta

311

Dietary boron, brain function, and cognitive performance.  

PubMed Central

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

Penland, J G

1994-01-01

312

The Modeling and Functional Connectivity of the Brain  

NASA Astrophysics Data System (ADS)

The brain is considered to be the most complex system, a fertile ground for understanding the complexity of its functions through dynamical modeling. In this talk, we present some biophysical models that help to reveal the complexity of visual functions of the brain through functional self-organization processes. We also present some recent results on how the functional connectivity arises and changes in the brain, reflecting the underlying dynamics of nervous systems. The implications of our work to the brain function are discussed. Note from Publisher: This article contains the abstract only.

Kim, Seunghwan

2008-12-01

313

Brain microvascular function during cardiopulmonary bypass  

SciTech Connect

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

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

1987-11-01

314

Behavioral plasticity in honey bees is associated with differences in brain microRNA transcriptome.  

PubMed

Small, non-coding microRNAs (miRNAs) have been implicated in many biological processes, including the development of the nervous system. However, the roles of miRNAs in natural behavioral and neuronal plasticity are not well understood. To help address this we characterized the microRNA transcriptome in the adult worker honey bee head and investigated whether changes in microRNA expression levels in the brain are associated with division of labor among honey bees, a well-established model for socially regulated behavior. We determined that several miRNAs were downregulated in bees that specialize on brood care (nurses) relative to foragers. Additional experiments showed that this downregulation is dependent upon social context; it only occurred when nurse bees were in colonies that also contained foragers. Analyses of conservation patterns of brain-expressed miRNAs across Hymenoptera suggest a role for certain miRNAs in the evolution of the Aculeata, which includes all the eusocial hymenopteran species. Our results support the intriguing hypothesis that miRNAs are important regulators of social behavior at both developmental and evolutionary time scales. PMID:22409512

Greenberg, J K; Xia, J; Zhou, X; Thatcher, S R; Gu, X; Ament, S A; Newman, T C; Green, P J; Zhang, W; Robinson, G E; Ben-Shahar, Y

2012-04-06

315

3D Standard Brain of the Red Flour Beetle Tribolium Castaneum: A Tool to Study Metamorphic Development and Adult Plasticity  

PubMed Central

The red flour beetle Tribolium castaneum is emerging as a further standard insect model beside Drosophila. Its genome is fully sequenced and it is susceptible for genetic manipulations including RNA-interference. We use this beetle to study adult brain development and plasticity primarily with respect to the olfactory system. In the current study, we provide 3D standard brain atlases of freshly eclosed adult female and male beetles (A0). The atlases include eight paired and three unpaired neuropils including antennal lobes (ALs), optic lobe neuropils, mushroom body calyces and pedunculi, and central complex. For each of the two standard brains, we averaged brain areas of 20 individual brains. Additionally, we characterized eight selected olfactory glomeruli from 10 A0 female and male beetles respectively, which we could unequivocally recognize from individual to individual owing to their size and typical position in the ALs. In summary, comparison of the averaged neuropil volumes revealed no sexual dimorphism in any of the reconstructed neuropils in A0 Tribolium brains. Both, the female and male 3D standard brain are also used for interspecies comparisons, and, importantly, will serve as future volumetric references after genetical manipulation especially regarding metamorphic development and adult plasticity.

Dreyer, David; Vitt, Holger; Dippel, Stefan; Goetz, Brigitte; el Jundi, Basil; Kollmann, Martin; Huetteroth, Wolf; Schachtner, Joachim

2009-01-01

316

Coupling energy metabolism with a mechanism to support brain-derived neurotrophic factor-mediated synaptic plasticity.  

PubMed

Synaptic plasticity and behaviors are likely dependent on the capacity of neurons to meet the energy demands imposed by neuronal activity. We used physical activity, a paradigm intrinsically associated with energy consumption/expenditure and cognitive enhancement, to study how energy metabolism interacts with the substrates for neuroplasticity. We found that in an area critical for learning and memory, the hippocampus, exercise modified aspects of energy metabolism by decreasing oxidative stress and increasing the levels of cytochrome c oxidase-II, a specific component of mitochondrial machinery. We infused 1,25-dihydroxyvitamin D3, a modulator of energy metabolism, directly into the hippocampus during 3 days of voluntary wheel running and measured its effects on brain-derived neurotrophic factor-mediated synaptic plasticity. Brain-derived neurotrophic factor is a central player for the effects of exercise on synaptic and cognitive plasticity. We found that 25-dihydroxyvitamin D3 decreased exercise-induced brain-derived neurotrophic factor but had no significant effect on neurotrophin-3 levels, thereby suggesting a level of specificity for brain-derived neurotrophic factor in the hippocampus. 25-Dihydroxyvitamin D3 injection also abolished the effects of exercise on the consummate end-products of brain-derived neurotrophic factor action, i.e. cyclic AMP response element-binding protein and synapsin I, and modulated phosphorylated calmodulin protein kinase II, a signal transduction cascade downstream to brain-derived neurotrophic factor action that is important for learning and memory. We also found that exercise significantly increased the expression of the mitochondrial uncoupling protein 2, an energy-balancing factor concerned with ATP production and free radical management. Our results reveal a fundamental mechanism by which key elements of energy metabolism may modulate the substrates of hippocampal synaptic plasticity. PMID:16580138

Vaynman, S; Ying, Z; Wu, A; Gomez-Pinilla, F

2006-03-31

317

Functional Genomics of Physiological Plasticity and Local Adaptation in Killifish  

PubMed Central

Evolutionary solutions to the physiological challenges of life in highly variable habitats can span the continuum from evolution of a cosmopolitan plastic phenotype to the evolution of locally adapted phenotypes. Killifish (Fundulus sp.) have evolved both highly plastic and locally adapted phenotypes within different selective contexts, providing a comparative system in which to explore the genomic underpinnings of physiological plasticity and adaptive variation. Importantly, extensive variation exists among populations and species for tolerance to a variety of stressors, and we exploit this variation in comparative studies to yield insights into the genomic basis of evolved phenotypic variation. Notably, species of Fundulus occupy the continuum of osmotic habitats from freshwater to marine and populations within Fundulus heteroclitus span far greater variation in pollution tolerance than across all species of fish. Here, we explore how transcriptome regulation underpins extreme physiological plasticity on osmotic shock and how genomic and transcriptomic variation is associated with locally evolved pollution tolerance. We show that F. heteroclitus quickly acclimate to extreme osmotic shock by mounting a dramatic rapid transcriptomic response including an early crisis control phase followed by a tissue remodeling phase involving many regulatory pathways. We also show that convergent evolution of locally adapted pollution tolerance involves complex patterns of gene expression and genome sequence variation, which is confounded with body-weight dependence for some genes. Similarly, exploiting the natural phenotypic variation associated with other established and emerging model organisms is likely to greatly accelerate the pace of discovery of the genomic basis of phenotypic variation.

Galvez, Fernando; Zhang, Shujun; Williams, Larissa M.; Oleksiak, Marjorie F.

2011-01-01

318

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

319

Functional MRI of food-induced brain responses  

Microsoft Academic Search

The ultimate goal of this research was to find central biomarkers of satiety, i.e., physiological measures in the brain that relate to subjectively rated appetite, actual food intake, or both. This thesis describes the changes in brain activity in response to food stimuli as measured by functional MRI, with a focus on the hypothalamus. The hypothalamus is a brain area

P. A. M. Smeets

2006-01-01

320

Organization, development and function of complex brain networks  

Microsoft Academic Search

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

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

2004-01-01

321

Changes in the Functional Asymmetry of the Brain in Wrestlers  

Microsoft Academic Search

The changes in the functional asymmetry of the brain influenced by the wrestler’s position, a lateacquired automatism, are analyzed in this work. The functional asymmetry of the brain is known to change under the influence of external factors [1, 2]; in sportsmen, it becomes more marked due to the development of the visual and spatial functions of the right hemisphere

S. V. Afanas'ev; M. M. Mikheev; O. P. Trachenko; N. N. Nikolaenko

2000-01-01

322

Neural plasticity and the Kennard principle: does it work for the preterm brain?  

PubMed

The Kennard principle suggests that the immature brain should be more able to recover from injury than the more developed brain. Curiously, preterm infants continue to have a high rate of debilitating neurodevelopmental handicaps despite a progressive improvement in structural damage to the brain, from acute necrotic injury of the periventricular white matter, with axonal loss in historical cohorts, to diffuse gliosis with trivial axonal damage. ?In the present review we examine recent evidence that disability after preterm birth is largely mediated by disturbed development of neuronal connections. Potential mechanisms include impaired white matter maturation associated with gliosis, suboptimal neuronal maturation, adverse effects of infection/inflammation on the cell environment, exposure to clinical therapies that modulate brain function (including maternal glucocorticoids), upregulation of physiological apoptosis and loss or misprogramming of progenitor cells in the subventricular zone. ?These findings suggest that insults during this critical phase alter the trajectory of brain development and that a key focus of basic science and clinical research should be to understand neuronal connectivity, as well as the triggers of cell death. PMID:23735123

Bennet, Laura; Van Den Heuij, Lotte; M Dean, Justin; Drury, Paul; Wassink, Guido; Jan Gunn, Alistair

2013-11-01

323

Studies of Brain Function and Behavior.  

National Technical Information Service (NTIS)

This study includes single brain cells and their discharge patterns during Pavlovian conditioning to development and evaluation of brain wave recording techniques in pilots flying high performance aircraft on pursuit missions. Much of the work has involve...

J. D. French W. R. Adey H. W. Magoun

1964-01-01

324

Ageing and diabetes: implications for brain function  

Microsoft Academic Search

Diabetes mellitus is associated with moderate cognitive deficits and neurophysiological and structural changes in the brain, a condition that may be referred to as diabetic encephalopathy. Diabetes increases the risk of dementia, particularly in the elderly. The emerging view is that the diabetic brain features many symptoms that are best described as “accelerated brain ageing.” The clinical characteristics of diabetic

Geert Jan Biessels; Lars P van der Heide; Amer Kamal; Ronald L. A. W Bleys; Willem Hendrik Gispen

2002-01-01

325

A functional role for REM sleep in brain maturation  

Microsoft Academic Search

The biological function of REM sleep is defined in terms of the functions of neural processes that selectively operate during the REM sleep state. The high amounts of REM sleep expressed by the young during a period of central nervous system plasticity suggest that one function of REM sleep is in development. The phenomenon of activity-dependent development has been clearly

Gerald A. Marks; James P. Shaffery; Arie Oksenberg; Samuel G. Speciale; Howard P. Roffwarg

1995-01-01

326

Acute sodium deficit triggers plasticity of the brain angiotensin type 1 receptors  

Microsoft Academic Search

The brain renin-angiotensin system (bRAS) is involved in the control of hydromineral balance. However, little information is available on the functional regulation of the bRAS as a consequence of sodium deficit in the extracellular fluid compartments. We used a pharmacological model of acute Na+ depletion (furosemide injections) to investigate changes of a major component of the bRAS, the hypothalamic angiotensin

Geneviève Charron; Sylvie Laforest; Caroline Gagnon; Guy Drolet; Didier Mouginot

2002-01-01

327

Brain dopamine receptor plasticity: testing a diathesis-stress hypothesis in an animal model  

Microsoft Academic Search

A wealth of clinical data supports a major role of genetic liability as well as of altered brain dopamine (DA) functioning\\u000a in different types of behavioural disturbances. Genetic influence on behaviour involves multiple genes, rather than one or\\u000a two major genes, as well as non-genetic sources of variance. Thus, in recent years, increasing attention has been devoted\\u000a to the involvement

S. Cabib; Alberto Oliverio; Rossella Ventura; Franco Lucchese; Stefano Puglisi-Allegra

1997-01-01

328

Maternal deprivation effects on brain plasticity and recognition memory in adolescent male and female rats.  

PubMed

Data from both human and animal studies suggest that exposure to stressful life events at neonatal stages may increase the risk of psychopathology at adulthood. In particular, early maternal deprivation, 24 h at postnatal day (pnd) 9, has been associated with persistent neurobehavioural changes similar to those present in developmental psychopathologies such as depression and schizophrenic-related disorders. Most neuropsychiatric disorders first appear during adolescence, however, the effects of MD on adolescent animals' brain and behaviour have been scarcely explored. In the present study, we aimed to investigate the emotional and cognitive consequences of MD in adolescent male and female rats, as well as possible underlying neurobiological mechanisms within frontal cortex and hippocampus. Animals were exposed to a battery of behavioural tasks, from pnd 35 to 42, to evaluate cognitive [spontaneous alternation task (SAT) and novel object test (NOT)] and anxiety-related responses [elevated plus maze (EPM)] during adolescence. Changes in neuronal and glial cells, alterations in synaptic plasticity as well as modifications in cannabinoid receptor expression were investigated in a parallel group of control and adolescent (pnd 40) male and female animals. Notably, MD induced a significant impairment in recognition memory exclusively among females. A generalized decrease in NeuN expression was found in MD animals, together with an increase in hippocampal glial fibrillar acidic protein (GFAP) expression exclusively among MD adolescent males. In addition, MD induced in the frontal cortex and hippocampus of male and female adolescent rats a significant reduction in brain derived neurotrophic factor (BDNF) and postsynaptic density (PSD95) levels, together with a decrease in synaptophysin in frontal cortex and neural cell adhesion molecule (NCAM) in hippocampus. MD induced, in animals of both sexes, a significant reduction in CB1R expression, but an increase in CB2R that was statistically significant only for the frontal cortex. Taken together, these results indicate that adolescent females are more vulnerable than males to the cognitive deficits derived from MD despite the changes in neural cells, cannabinoid receptors, as well as the reduction in neural plasticity seem to be similar in both sexes. Further investigation is needed to understand the neurobiological mechanisms underlying the sexual dimorphisms associated to the MD effects, and thus, for a better understanding of the specific sex-dependent vulnerabilities to early life stress. This article is part of the Special Issue entitled 'Neurodevelopmental Disorders'. PMID:22939999

Marco, Eva M; Valero, Manuel; de la Serna, Oscar; Aisa, Barbara; Borcel, Erika; Ramirez, Maria Javier; Viveros, María-Paz

2012-08-24

329

Mapping brain function in freely moving subjects.  

PubMed

Expression of many fundamental mammalian behaviors such as, for example, aggression, mating, foraging or social behaviors, depend on locomotor activity. A central dilemma in the functional neuroimaging of these behaviors has been the fact that conventional neuroimaging techniques generally rely on immobilization of the subject, which extinguishes all but the simplest activity. Ideally, imaging could occur in freely moving subjects, while presenting minimal interference with the subject's natural behavior. Here we provide an overview of several approaches that have been undertaken in the past to achieve this aim in both tethered and freely moving animals, as well as in nonrestrained human subjects. Applications of specific radiotracers to single photon emission computed tomography and positron emission tomography are discussed in which brain activation is imaged after completion of the behavioral task and capture of the tracer. Potential applications to clinical neuropsychiatry are discussed, as well as challenges inherent to constraint-free functional neuroimaging. Future applications of these methods promise to increase our understanding of the neural circuits underlying mammalian behavior in health and disease. PMID:15465134

Holschneider, Daniel P; Maarek, Jean-Michel I

2004-09-01

330

Protein kinase A-dependent enhanced NMDA receptor function in pain-related synaptic plasticity in rat amygdala neurones  

PubMed Central

Mechanisms of pain-related plasticity in the amygdala, a key player in emotionality, were studied at the cellular and molecular levels in a model of arthritic pain. The influence of the arthritis pain state induced in vivo on synaptic transmission and N-methyl-d-aspartate (NMDA) receptor function was examined in vitro using whole-cell voltage-clamp recordings of neurones in the latero-capsular part of the central nucleus of the amygdala (CeA), which is now defined as the ‘nociceptive amygdala’. Synaptic transmission was evoked by electrical stimulation of afferents from the pontine parabrachial area (part of the spino-parabrachio-amygdaloid pain pathway) in brain slices from control rats and from arthritic rats. This study shows that pain-related synaptic plasticity is accompanied by protein kinase A (PKA)-mediated enhanced NMDA-receptor function and increased phosphorylation of NMDA-receptor 1 (NR1) subunits. Synaptic plasticity in the arthritis pain model, but not normal synaptic transmission in control neurones, was inhibited by a selective NMDA receptor antagonist. Accordingly, an NMDA receptor-mediated synaptic component was recorded in neurones from arthritic animals, but not in control neurones, and was blocked by inhibition of PKA but not protein kinase C (PKC). Exogenous NMDA evoked a larger inward current in neurones from arthritic animals than in control neurones, indicating a postsynaptic effect. Paired-pulse facilitation, a measure of presynaptic mechanisms, was not affected by an NMDA-receptor antagonist. Increased levels of phosphorylated NR1 protein, but not of total NR1, were measured in the CeA of arthritic rats compared to controls. Our results suggest that pain-related synaptic plasticity in the amygdala involves a critical switch of postsynaptic NMDA receptor function through PKA-dependent NR1 phosphorylation.

Bird, Gary C; Lash, L Leanne; Han, Jeong S; Zou, Xiaoju; Willis, William D; Neugebauer, Volker

2005-01-01

331

Executive Functions in Children with Traumatic Brain Injury  

Microsoft Academic Search

The maturational course of the development of executive functioning abilities is dependent on the functional capacity of the human brain. Unfortunately, there is a dearth of standardized functional assessments of executive functioning abilities for children. The present article describes neurodevelopment of executive functioning and several recent measures of executive functioning that have been developed to assess maturational periods of specific

Arthur MacNeill Horton Jr; Henry V. Soper; Cecil R. Reynolds

2010-01-01

332

Development of Large-Scale Functional Brain Networks in Children  

Microsoft Academic Search

The ontogeny of large-scale functional organization of the human brain is not well understood. Here we use network analysis of intrinsic functional connectivity to characterize the organization of brain networks in 23 children (ages 7-9 y) and 22 young-adults (ages 19-22 y). Comparison of network properties, including path-length, clustering-coefficient, hierarchy, and regional connectivity, revealed that although children and young-adults' brains

Kaustubh Supekar; Mark Musen; Vinod Menon

2009-01-01

333

Toward Elucidating Language Functions in the Brain  

Microsoft Academic Search

Human intelligence is characterized by the use of language rather than the brain hardware. The human brainware consists of\\u000a a neural system as hardware and a language system as software. Language was created by the brain hardware, and the human brain\\u000a evolved together with language over millions of years. It is, therefore, necessary to take two approaches to create the

Michio Sugeno

2008-01-01

334

The load separation criterion in elastic-plastic fracture mechanics: Rate and temperature dependence of the material plastic deformation function in an ABS resin  

NASA Astrophysics Data System (ADS)

This work is aimed at analyzing the effects of temperature and loading rate on the plastic deformation behavior of an acrylonitrile-butadiene-styrene (ABS) resin during a fracture process. According to the load separation criterion, the plastic deformation behavior during the fracture process of an elastic-plastic material is described by a plastic deformation function. For the ABS here examined, the material plastic deformation function was constructed at different temperatures and loading rates, by single edge notched in bending (SEB) tests on blunt notched specimens. Both low and moderately high (impact) loading rates were explored. For the various conditions of temperature and loading rate the material yield stress was also measured by uniaxial tensile tests. The relationships between material deformation function and yield stress were researched and discussed.

Agnelli, Silvia; Baldi, Francesco; Riccò, Theonis

2012-07-01

335

What Is the Function of Mind and Brain?  

Microsoft Academic Search

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

David C. Geary

1998-01-01

336

Partial correlation for functional brain interactivity investigation in functional MRI.  

PubMed

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

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

2006-06-13

337

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

PubMed

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

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

2013-10-17

338

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

PubMed Central

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

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

2013-01-01

339

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

Microsoft Academic Search

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

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

2008-01-01

340

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

ERIC Educational Resources Information Center

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

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

2012-01-01

341

Subchronic Alpha-Linolenic Acid Treatment Enhances Brain Plasticity and Exerts an Antidepressant Effect: A Versatile Potential Therapy for Stroke  

Microsoft Academic Search

Omega-3 polyunsaturated fatty acids are known to have therapeutic potential in several neurological and psychiatric disorders. However, the molecular mechanisms of action underlying these effects are not well elucidated. We previously showed that alpha-linolenic acid (ALA) reduced ischemic brain damage after a single treatment. To follow-up this finding, we investigated whether subchronic ALA treatment promoted neuronal plasticity. Three sequential injections

Nicolas Blondeau; Carine Nguemeni; David N Debruyne; Marie Piens; Xuan Wu; Hongna Pan; XianZhang Hu; Carine Gandin; Robert H Lipsky; Jean-Christophe Plumier; Ann M Marini; Catherine Heurteaux

2009-01-01

342

The connection between rhythmicity and brain function.  

PubMed

Although rhythm and music are not entirely synonymous terms, rhythm constitutes one of the most essential structural and organizational elements of music. When considering the effect of music on human adaptation, the profound effect of rhythm on the motor system strongly suggests that the time structure of music is the essential element relating music specifically to motor behavior. Why the motor system appears so sensitive to auditory priming and timing stimulation can only be partially answered so far. The high-performance function of the auditory system regarding processing of time information makes good functional sense within the constraints of auditory sensory processing. Thus, the motor system sensitivity to auditory entrainment may simply be an evolutionary useful function of taking advantage of the specific and unique aspects of auditory information processing for enhanced control and organization of motor behavior; e.g, in the time domain. Unlike processes in the motor system, many other physiological processes cannot be effectively entrained by external sensory stimuli. For example, there is probably a very good protective reason why other cyclical physiological processes (e.g., autonomic processes such as heart rate) have only very limited entrainment capacity to external rhythmic cues. Some of the basic auditory-motor arousal connections may also have their basis in adaptive evolutionary processes related to survival behavior; e.g., in fight or flight reactions. Much of the "why" in auditory-motor interactions, however, remains unknown heuristically. In the absence of this knowledge, great care should be taken to not compensate for this lack of understanding of specific cause and effect processes by assigning anthropomorphic descriptions to the behavior of biological and physical systems. The unraveling of the perceptual, physiological, and neuroanatomical basis of the interaction between rhythm and movement has been, and continues to be, a fascinating endeavor with important ramifications for the study of brain function, sensory perception, and motor behavior. One of the most exciting findings in this research, however, may be the evidence that the interaction between auditory rhythm and physical response can be effectively harnessed for specific therapeutic purposes in the rehabilitation of persons with movement disorders. PMID:10101675

Thaut, M H; Kenyon, G P; Schauer, M L; McIntosh, G C

343

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

PubMed

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

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

2013-08-20

344

Brain plasticity in the motor network is correlated with disease progression in amyotrophic lateral sclerosis.  

PubMed

Objective: To test the influence of functional cerebral reorganization in amyotrophic lateral sclerosis (ALS) on disease progression. Methods: Nineteen predominantly right-handed ALS patients and 21 controls underwent clinical evaluation, functional Magnetic Resonance Imaging (fMRI), and diffusion tensor imaging. Patients were clinically re-evaluated 1 year later and followed until death. For fMRI, subjects executed and imagined a simple hand-motor task. Between-group comparisons were performed, and correlations were searched with motor deficit arm Medical Research Council (MRC) score, disease progression ALS Functional Rating Scale (ALSFRS), and survival time. Results: By the MRC score, the hand strength was lowered by 12% in the ALS group predominating on the right side in accordance with an abnormal fractional anisotropy (FA) limited to the left corticospinal tract (37.3% reduction vs. controls P < 0.01). Compared to controls, patients displayed overactivations in the controlateral parietal (P < 0.004) and somatosensory (P < 0.004) cortex and in the ipsilateral parietal (P < 0.01) and somatosensory (P < 0.01) cortex to right-hand movement. Movement imagination gave similar results while no difference occurred with left-hand tasks. Stepwise regression analysis corrected for multiple comparisons showed that controlateral parietal activity was inversely correlated with disease progression (R(2) = 0.43, P = 0.001) and ipsilateral somatosensory activations with the severity of the right-arm deficit (R(2) = 0.48, P = 0.001). Conclusions: Cortical Blood Oxygen Level Dependent (BOLD) signal changes occur in the brain of ALS patients during a simple hand-motor task when the motor deficit is still moderate. It is correlated with the rate of disease progression suggesting that brain functional rearrangement in ALS may have prognostic implications. Hum Brain Mapp 34:2391-2401, 2013. © 2012 Wiley Periodicals, Inc. PMID:22461315

Poujois, Aurélia; Schneider, Fabien C; Faillenot, Isabelle; Camdessanché, Jean-Philippe; Vandenberghe, Nadia; Thomas-Antérion, Catherine; Antoine, Jean-Christophe

2012-03-28

345

Functional brain connectivity as revealed by singular spectrum analysis.  

PubMed

Correlation based measures have widely been used to characterize brain connectivity. In this paper, a new approach based on singular spectrum analysis is proposed to characterize brain connectivity. It is obtained by deriving the common basis vector of two or more trajectory matrices associated with functional brain responses. This approach has the advantage illustrating the existence of joint variations of the functional brain responses and to characterize the correlation structure. The performance of the method are illustrated on both simulated autoregressive data and real fMRI data. PMID:23367097

Seghouane, Abd-Krim; Shah, Adnan

2012-01-01

346

UNDERSTANDING THE NEUROBIOLOGICAL MECHANISMS OF LEARNING AND MEMORY: MEMORY SYSTEMS OF THE BRAIN, LONG TERM POTENTIATION AND SYNAPTIC PLASTICITY PART III B  

Microsoft Academic Search

SUMMARY One of the central issues in neuroscience is concerned with the activity-dependent synaptic plasticity in learning and memory. In such context, changing the strength of synaptic activity between neurons has been widely accepted as the mechanism responsible by which memory traces are encoded and stored in the brain. Thus, the synaptic plasticity and memory hypothesis (SPM hypothesis) shows that

Philippe Leff; Héctor Romo; Maura Matus; Adriana Hernández; Juan Carlos Calva; Rodolfo Acevedo; Carlos Torner; Rafael Gutiérrez; Benito Anton

2002-01-01

347

Enabling Functional Neural Circuit Simulations with Distributed Computing of Neuromodulated Plasticity  

PubMed Central

A major puzzle in the field of computational neuroscience is how to relate system-level learning in higher organisms to synaptic plasticity. Recently, plasticity rules depending not only on pre- and post-synaptic activity but also on a third, non-local neuromodulatory signal have emerged as key candidates to bridge the gap between the macroscopic and the microscopic level of learning. Crucial insights into this topic are expected to be gained from simulations of neural systems, as these allow the simultaneous study of the multiple spatial and temporal scales that are involved in the problem. In particular, synaptic plasticity can be studied during the whole learning process, i.e., on a time scale of minutes to hours and across multiple brain areas. Implementing neuromodulated plasticity in large-scale network simulations where the neuromodulatory signal is dynamically generated by the network itself is challenging, because the network structure is commonly defined purely by the connectivity graph without explicit reference to the embedding of the nodes in physical space. Furthermore, the simulation of networks with realistic connectivity entails the use of distributed computing. A neuromodulated synapse must therefore be informed in an efficient way about the neuromodulatory signal, which is typically generated by a population of neurons located on different machines than either the pre- or post-synaptic neuron. Here, we develop a general framework to solve the problem of implementing neuromodulated plasticity in a time-driven distributed simulation, without reference to a particular implementation language, neuromodulator, or neuromodulated plasticity mechanism. We implement our framework in the simulator NEST and demonstrate excellent scaling up to 1024 processors for simulations of a recurrent network incorporating neuromodulated spike-timing dependent plasticity.

Potjans, Wiebke; Morrison, Abigail; Diesmann, Markus

2010-01-01

348

Habitat-dependent and -independent plastic responses to social environment in the nine-spined stickleback (Pungitius pungitius) brain  

PubMed Central

The influence of environmental complexity on brain development has been demonstrated in a number of taxa, but the potential influence of social environment on neural architecture remains largely unexplored. We investigated experimentally the influence of social environment on the development of different brain parts in geographically and genetically isolated and ecologically divergent populations of nine-spined sticklebacks (Pungitius pungitius). Fish from two marine and two pond populations were reared in the laboratory from eggs to adulthood either individually or in groups. Group-reared pond fish developed relatively smaller brains than those reared individually, but no such difference was found in marine fish. Group-reared fish from both pond and marine populations developed larger tecta optica and smaller bulbi olfactorii than individually reared fish. The fact that the social environment effect on brain size differed between marine and pond origin fish is in agreement with the previous research, showing that pond fish pay a high developmental cost from grouping while marine fish do not. Our results demonstrate that social environment has strong effects on the development of the stickleback brain, and on the brain's sensory neural centres in particular. The potential adaptive significance of the observed brain-size plasticity is discussed.

Gonda, Abigel; Herczeg, Gabor; Merila, Juha

2009-01-01

349

BrainKnowledge: A Human Brain Function Mapping Knowledge-Base System  

Microsoft Academic Search

Associating fMRI image datasets with the available literature is crucial for the analysis and interpretation of fMRI data.\\u000a Here, we present a human brain function mapping knowledge-base system (BrainKnowledge) that associates fMRI data analysis\\u000a and literature search functions. BrainKnowledge not only contains indexed literature, but also provides the ability to compare\\u000a experimental data with those derived from the literature. BrainKnowledge

Mei-Yu Hsiao; Chien-Chung Chen; Jyh-Horng Chen

2011-01-01

350

Rho GTPase-dependent plasticity of dendritic spines in the adult brain  

PubMed Central

Brain activity is associated with structural changes in the neural connections. However, in vivo imaging of the outer cortical layers has shown that dendritic spines, on which most excitatory synapses insist, are predominantly stable in adulthood. Changes in dendritic spines are governed by small GTPases of the Rho family through modulation of the actin cytoskeleton. Yet, while there are abundant data about this functional effect of Rho GTPases in vitro, there is limited evidence that Rho GTPase signaling in the brain is associated with changes in neuronal morphology. In the present work, both chronic in vivo two-photon imaging and Golgi staining reveal that the activation of Rho GTPases in the adult mouse brain is associated with little change of dendritic spines in the apical dendrites of primary visual cortex pyramidal neurons. On the contrary, considerable increase in spine density is observed (i) in the basal dendrites of the same neurons (ii) in both basal and apical dendrites of the hippocampal CA1 pyramidal cells. While confirming that Rho GTPase-dependent increase in spine density can be substantial, the study indicates region and dendrite selectivity with relative stability of superficial cortical circuits.

Martino, Assunta; Ettorre, Michele; Musilli, Marco; Lorenzetto, Erika; Buffelli, Mario; Diana, Giovanni

2013-01-01

351

Age-dependent plasticity in the superior temporal sulcus in deaf humans: a functional MRI study  

Microsoft Academic Search

BACKGROUND: Sign-language comprehension activates the auditory cortex in deaf subjects. It is not known whether this functional plasticity in the temporal cortex is age dependent. We conducted functional magnetic-resonance imaging in six deaf signers who lost their hearing before the age of 2 years, five deaf signers who were >5 years of age at the time of hearing loss and

Norihiro Sadato; Hiroki Yamada; Tomohisa Okada; Masaki Yoshida; Takehiro Hasegawa; Ken-Ichi Matsuki; Yoshiharu Yonekura; Harumi Itoh

2004-01-01

352

The Strength of Plastic Bonded Explosives as a Function of Pressure, Strain Rate and Temperature  

Microsoft Academic Search

Measurements as a function of strain rate and temperature have indicated the importance of the polymer binder in determining the strength of plastic bonded explosives at ambient conditions and low strain rate. Recent measurements of strength as a function of pressure further support this conclusion. As pressure or strain rate are increased or temperature is decreased the strength increases as

Donald Wiegand

2005-01-01

353

NMDA receptor function, memory, and brain aging  

PubMed Central

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

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

2000-01-01

354

Decoding brain states using functional magnetic resonance imaging  

Microsoft Academic Search

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

Dongha Lee; Changwon Jang; Hae-Jeong Park

2011-01-01

355

Effects of MDMA on Complex Brain Function in Laboratory Animals  

Microsoft Academic Search

FREDERICK, D.L. AND M.G. PAULE. Effects of MDMA on complex brain function in laboratory animals. NEUROSCI BIOBEHAV REV 21(1) 67–78, 1997.—This review surveys experiments that have examined the effects of acute and chronic MDMA exposure on schedule-controlled operant behaviors thought to engender responses that reflect the expression of complex brain functions. Such functions include time estimation, short-term memory, learning, motivation,

DAVID L FREDERICK; MERLE G PAULE

1997-01-01

356

An Autoradiographic Analysis Of Rat Brain Nicotinic Receptor Plasticity Following Dietary Choline Modification  

PubMed Central

Choline is known to be involved with numerous physiological functions of the nervous system and also acts as a direct acting agonist of ?7 nicotinic acetylcholine receptors (nAChRs). The purpose of this study was to conduct a brain region-specific evaluation of changes in nAChR subtype expression following dietary choline modification. In addition, we assessed changes in body weight, food/water intake, as well as changes spatial learning (Morris Water Maze) in response to dietary choline modification. Male Sprague Dawley rats were exposed to standard, choline supplemented or choline deficient diets for periods of 14 or 28 days. Choline supplemented animals gained significantly less weight over the course of the experiment, in spite of the fact that there were minimal differences in food consumption between the dietary regimens. Spatial memory did not differ between animals maintained on a standard rat diet, and the choline supplemented food. Brains of the animals kept on the diets for 14 and 28 days were used for quantitative autoradiographic analysis of nicotinic receptor subtypes using 125I-Bungarotoxin (?7) and 125I-Epibatidine (non-?7). There were no significant differences in nicotinic receptor binding or physiologic parameters measured between animals fed standard and choline deficient diets. However 2 weeks of dietary choline supplementation caused significant up-regulation of ?7 receptors without significant effect on the density of non-?7 nAChRs. Increases in BTX binding predominantly occurred in cortical and hippocampal brain regions and ranged between 14 and 30 percent depending on the brain region. The results of our study suggest that choline acts as a selective agonist at ?7 nicotinic cholinergic receptors in the rat central nervous system.

Guseva, M.V.; Hopkins, D.M.; Pauly, J.R.

2007-01-01

357

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

358

Anterior thalamic nuclei lesions in rats disrupt markers of neural plasticity in distal limbic brain regions  

PubMed Central

In two related experiments, neurotoxic lesions were placed in the anterior thalamic nuclei of adult rats. The rats were then trained on behavioral tasks, immediately followed by the immunohistochemical measurement of molecules linked to neural plasticity. These measurements were made in limbic sites including the retrosplenial cortex, the hippocampal formation, and parahippocampal areas. In Experiment 1, rats with unilateral anterior thalamic lesions explored either novel or familiar objects prior to analysis of the immediate-early gene zif268. The lesions reduced zif268 activity in the granular retrosplenial cortex and postsubiculum. Exploring novel objects resulted in local changes of hippocampal zif268, but this change was not moderated by anterior thalamic lesions. In Experiment 2, rats that had received either bilateral anterior thalamic lesions or control surgeries were exposed to novel room cues while running in the arms of a radial maze. In addition to zif268, measurements of c-AMP response element binding protein (CREB), phosphorylated CREB (pCREB), and growth associated protein43 (GAP-43) were made. As before, anterior thalamic lesions reduced zif268 in retrosplenial cortex and postsubiculum, but there were also reductions of pCREB in granular retrosplenial cortex. Again, the hippocampus did not show lesion-induced changes in zif268, but there were differential effects on CREB and pCREB consistent with reduced levels of hippocampal CREB phosphorylation following anterior thalamic damage. No changes in GAP-43 were detected. The results not only point to changes in several limbic sites (retrosplenial cortex and hippocampus) following anterior thalamic damage, but also indicate that these changes include decreased levels of pCREB. As pCREB is required for neuronal plasticity, partly because of its regulation of immediate early-gene expression, the present findings reinforce the concept of an ‘extended hippocampal system’ in which hippocampal function is dependent on distal sites such as the anterior thalamic nuclei.

Dumont, J.R.; Amin, E.; Poirier, G.L.; Albasser, M.M.; Aggleton, J.P.

2012-01-01

359

The Efficiency of a Small-World Functional Brain Network  

NASA Astrophysics Data System (ADS)

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

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

2012-04-01

360

The Effects of Brain Damage on Visual Functioning in Children  

Microsoft Academic Search

Medical and educational professionals arc working with a growing population of in- fants and children who have brain dam- age. This article reviews research on the effects of brain damage on visual function- ing in children, the tests that determine these effects, and the implications of these effects for prognosis and intervention. Background

P. K. Alexander

1990-01-01

361

Functional Brain Imaging Alterations in Acne Patients Treated With Isotretinoin  

Microsoft Academic Search

Objective: Although there have been case reports suggesting a relationship be- tween treatment with the acne medica- tion isotretinoin and the development of depression and suicide, this topic remains controversial. In order for isotretinoin to cause depression, it must have an effect on the brain; however, the effects of isotretinoin on brain functioning in acne patients have not been established.

J. Douglas Bremner; Negar Fani; M. S. Ali Ashraf; John R. Votaw; Marijn E. Brummer; D. Thomas Cummins; Viola Vaccarino; Mark M. Goodman; D. Lai Reed; Sajid Siddiq; Charles B. Nemeroff

2005-01-01

362

Reliability of Individual Functional MRI Brain Mapping of Language  

Microsoft Academic Search

The use of individual brain mapping for a single case study implicitly assumes that the pattern of activation obtained in a single session represents the subject's functional neuroanatomy. It is therefore essential to estimate the potential variability of brain activation in individuals. To this purpose, the authors compared the pattern of activation determined by statistical parametric mapping (SPM 99) in

Hélène Otzenberger; Daniel Gounot; Corinne Marrer; Izzie Jacques Namer; Marie-Noëlle Metz-Lutz

2005-01-01

363

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

364

Alpha oscillations in brain functioning: an integrative theory  

Microsoft Academic Search

The old concept stating that EEG alpha (10-Hz) activity reflects passive or idling states of the brain is giving way to modern views of 10-Hz oscillations in relation to diverse brain functions comprising sensory, motor, and memory processes: (1) Spontaneous alpha activity is not pure noise as shown by methods of chaos analysis. (2) Evoked alpha oscillations patterns (precisely time-locked

E. Basar; M. Schurmann; C. Basar-eroglu; S. Karakas

1997-01-01

365

Magnetic resonance imaging mapping of brain function. Human visual cortex  

Microsoft Academic Search

Magnetic resonance imaging (MRI) studies of human brain activity are described. Task-induced changes in brain cognitive state were measured using high-speed MRI techniques sensitive to changes in cerebral blood volume (CBV), blood flow (CBF), and blood oxygenation. These techniques were used to generate the first functional MRI maps of human task activation, by using a visual stimulus paradigm. The methodology

J. W. Belliveau; K. K. Kwong; D. N. Kennedy; J. R. Baker; C. E. Stern; R. Benson; D. A. Chesler; R. M. Weisskoff; M. S. Cohen; R. B. Tootell; P. T. Fox; T. J. Brady

1992-01-01

366

Spatial expression and functional flexibility of monocarboxylate transporter isoforms in the zebrafish brain.  

PubMed

The present study provides in vivo evidence to prove the functional plasticity of monocarboxylate transporters (MCTs) in brains of vertebrates using zebrafish (Danio rerio) as a model. In the mammalian central nervous system (CNS), energy demands are largely met by oxidation of glucose. In recent studies, in addition to glucose, lactate is also considered an energy substrate for the CNS. Astrocytes were demonstrated to play an important role in transporting lactate as metabolic substrate from capillaries to neurons through monocarboxylate transporters (MCTs). The present study was to use zebrafish as an in vivo model to test the hypothesis of whether the various MCT homologs play differential roles in the development and functioning of the CNS. Using RT-PCR and double in situ hybridization coupling with immunocytochemical staining experiments, zebrafish MCTs1-4 were all found to be expressed in brains of embryos, and were further elucidated to be localized in both neurons and astrocytes. Loss-of-functions by morpholino knockdown further provided in vivo evidences to infer that zMCTs1, -2, and -4 may be involved in metabolite transport and functioning in the developing brain. Subsequent rescue experiments with capped mRNAs of specific isoforms further indicated that zMCT2 is an indispensable monocarboxylate-transporting route for CNS development and function in zebrafish. This information is essential for identifying proper candidates of MCT isoforms that are involved in the development and functioning of the CNS. PMID:23384686

Tseng, Yung-Che; Kao, Zhi-Jie; Liu, Sian-Tai; Chen, Ruo-Dong; Hwang, Pung-Pung

2013-02-04

367

Functional plasticity of macrophages: reversible adaptation to changing microenvironments  

Microsoft Academic Search

There has been substantial research ac- tivity in the past decade directed at phenotyping macrophage lineages and defining macrophage functional subsets or patterns of activity. The em- phasis over the past 2-3 years has been to divide macrophage functional patterns into type 1 (Th1- driven) or type 2 (Th2-driven) functions. However, a huge array of environmental factors (including cytokines, chemokines,

Robert D. Stout; Jill Suttles

2004-01-01

368

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.

369

Neural Plasticity: For Good and Bad  

Microsoft Academic Search

The brain's ability to change its organization and function is necessary for normal development of the nervous system and it makes it possible to adapt to changing demands but it can also cause disorders when going awry. This property, known as neural plasticity, is only evident when induced, very much like genes. Plastic changes may be programmed and providing a

A. R. Møller

2008-01-01

370

Stress and the Adolescent Brain  

Microsoft Academic Search

During adolescence the brain shows remarkable changes in both structure and function. The plasticity exhibited by the brain during this pubertal period may make individuals more vulnerable to pertur- bations, such as stress. Although much is known about how exposure to stress and stress hormones during perinatal development and adulthood affect the structure and function of the brain, relatively little

RUSSELL D. ROMEO; BRUCE S. MCEWEN

2006-01-01

371

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

Microsoft Academic Search

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

Mark H. Johnson; Tobias Grossmann; Kathrin Cohen Kadosh

2009-01-01

372

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

Microsoft Academic Search

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

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

1995-01-01

373

BrainMap: A Database of Functional Neuroanatomy Derived from Human Brain Images.  

National Technical Information Service (NTIS)

The goal of the BrainMap project is to promote efficient compilation, analysis, and dissemination of the rapidly growing body of information about the functional organization of the human brain which can be provided by medical imaging techniques such as P...

1991-01-01

374

Images of the working brain: understanding human brain function with positron emission tomography  

Microsoft Academic Search

In the past 15 years positron emission tomography (PET) has become a settled method of imaging the functioning human brain, both in normal volunteers and in patients with various disorders. Much of the work on sensory systems has been on the visual system, a conveniently studied and very important part of the brain. The motor system in health and disease

John D. G Watson

1997-01-01

375

Role of Brain Allopregnanolone in the Plasticity of gamma -aminobutyric Acid Type A Receptor in Rat Brain during Pregnancy and after Delivery  

Microsoft Academic Search

The relation between changes in brain and plasma concentrations of neurosteroids and the function and structure of gamma -aminobutyric acid type A (GABAA) receptors in the brain during pregnancy and after delivery was investigated in rats. In contrast with plasma, where all steroids increased in parallel, the kinetics of changes in the cerebro-cortical concentrations of progesterone, allopregnanolone (AP), and allotetrahydrodeoxycorticosterone

A. Concas; M. C. Mostallino; P. Porcu; P. Follesa; M. L. Barbaccia; M. Trabucchi; R. H. Purdy; P. Grisenti; G. Biggio

1998-01-01

376

Linking structure and function: Information processing in the brain.  

National Technical Information Service (NTIS)

Traditionally, theories of function in neuroscience have emerged from physiology. Physiologists have suggested a number of means by which information in the brain can be processed, yet the principles underlying the generation of these phenomena are not we...

M. A. V. Gremillion

1990-01-01

377

Functional Imaging of Dolphin Brain Metabolism and Blood Flow.  

National Technical Information Service (NTIS)

This report documents the first use of magnetic resonance images (MRls) of living dolphins to register functional brain scans, allowing for the exploration of potential mechanisms of unihemispheric sleep. Diazepam has been shown to induce unihemispheric s...

S. Ridgway J. Finneran D. Carder M. Keogh W. Van Bonn

2006-01-01

378

Brain-derived neurotrophic factor (BDNF) promotes adaptive plasticity within the spinal cord and mediates the beneficial effects of controllable stimulation  

PubMed Central

Brain-derived neurotrophic factor (BDNF) has been characterized as a potent modulator of neural plasticity in both the brain and spinal cord. The present experiments use an in vivo model system to demonstrate that training with controllable stimulation increases spinal BDNF expression and engages a BDNF-dependent process that promotes adaptive plasticity. Spinally transected rats administered legshock whenever one hindlimb is extended (controllable stimulation) exhibit a progressive increase in flexion duration. This simple form of response-outcome (instrumental) learning is not observed when shock is given independent of leg position (uncontrollable stimulation). Uncontrollable electrical stimulation also induces a lasting effect that impairs learning for up to 48 hrs. Training with controllable shock can counter the adverse consequences of uncontrollable stimulation, to both prevent and reverse the learning deficit. Here it is shown that the protective and restorative effect of instrumental training depends on BDNF. Cellular assays showed that controllable stimulation increased BDNF mRNA expression and protein within the lumbar spinal cord. These changes were associated with an increase in the BDNF receptor TrkB protein within the dorsal horn. Evidence is then presented that these changes play a functional role in vivo. Application of a BDNF inhibitor (TrkB-IgG) blocked the protective effect of instrumental training. Direct (intrathecal) application of BDNF substituted for instrumental training to block both the induction and expression of the learning deficit. Uncontrollable stimulation also induced an increase in mechanical reactivity (allodynia) and this too was prevented by BDNF. TrkB-IgG blocked the restorative effect of instrumental training and intrathecal BDNF substituted for training to reverse the deficit. Taken together, these findings outline a critical role for BDNF in mediating the beneficial effects of controllable stimulation on spinal plasticity.

Huie, J. Russell; Garraway, Sandra M.; Baumbauer, Kyle M.; Hoy, Kevin C.; Beas, Blanca S.; Montgomery, Karienn S.; Bizon, Jennifer L.; Grau, James W.

2011-01-01

379

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

PubMed Central

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

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

2013-01-01

380

Gender Effect on Functional Networks in Resting Brain  

Microsoft Academic Search

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

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

2007-01-01

381

Intrinsic functional architecture in the anaesthetized monkey brain  

Microsoft Academic Search

The traditional approach to studying brain function is to measure physiological responses to controlled sensory, motor and cognit- ive paradigms. However, most of the brain's energy consumption isdevotedtoongoingmetabolicactivitynotclearlyassociatedwith any particular stimulus or behaviour1. Functional magnetic res- onance imaging studies in humans aimed at understanding this ongoing activity have shown that spontaneous fluctuations of the blood-oxygen-level-dependent signal occur continuously in the

J. L. Vincent; G. H. Patel; M. D. Fox; A. Z. Snyder; J. T. Baker; D. C. Van Essen; J. M. Zempel; L. H. Snyder; M. Corbetta; M. E. Raichle

2007-01-01

382

Improvement of brain function in hemodialysis patients treated with erythropoietin  

Microsoft Academic Search

Improvement of brain function in hemodialysis patients treated with erythropoietin. To evaluate the effects of recombinant human erythropoietin (rHuEPO) on brain function, 15 chronic hemodialysis patients were studied by event-related P300, stimulus-related evoked potentials, and trailmaking before (hematocrit 22.7%) and after rHuEPO (hematocrit 30.6%). P300 peak latency elicited by a tone discrimination paradigm improved (391 before vs. 366 ms after;

Georg Grimm; Felix Stockenhuber; Bruno Schneeweiss; Christian Madl; Josef Zeitlhofer; Barbara Schneider

1990-01-01

383

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

384

Democratic reinforcement: A principle for brain function  

Microsoft Academic Search

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

Dimitris Stassinopoulos; Per Bak

1995-01-01

385

Frontal brain asymmetry and immune function  

Microsoft Academic Search

The relation between brain activity and the immune system was evaluated by assessing immune responses in 20 healthy women who manifested extreme differences in the asymmetry of frontal cortex activation. One group showed extreme and stable left frontal activation; the other group showed extreme and stable right frontal activation. As predicted, women with extreme right frontal activation had significantly lower

Duck-hee Kang; Richard J. Davidson; Christopher L. Coe; Robert E. Wheeler

1991-01-01

386

Functional plasticity of macrophages: in situ reprogramming of tumor-associated macrophages  

PubMed Central

The extent to which the functional heterogeneity of M?s is dependent on the differentiation of functional sublineages remains unresolved. One alternative hypothesis proposes that M?s are functionally plastic cells, which are capable of altering their functional activities progressively in response to progressively changing signaling molecules generated in their microenvironment. This “functional plasticity” hypothesis predicts that the functionally polarized M?s in chronic pathologies do not represent M? sublineages but rather, are mutable phenotypes sustained by chronic signaling from the pathological environment. Solid TAM?s are chronically polarized to provide activities that support tumor growth and metastasis and suppress adaptive immune responses. In support of the functional plasticity hypothesis, administration of slow-release microsphere-encapsulated IL-12 successfully reprogrammed TAM?s in situ, reducing M? support of tumor growth and metastasis and enhancing M? proimmunogenic activities. Increased knowledge of how M? function is regulated and how polarized M?s can be reprogrammed in situ will increase our ability to control M? function in a variety of pathological states, including cancer and chronic inflammatory disease.

Stout, Robert D.; Watkins, Stephanie K.; Suttles, Jill

2009-01-01

387

Standardized Environmental Enrichment Supports Enhanced Brain Plasticity in Healthy Rats and Prevents Cognitive Impairment in Epileptic Rats  

PubMed Central

Environmental enrichment of laboratory animals influences brain plasticity, stimulates neurogenesis, increases neurotrophic factor expression, and protects against the effects of brain insult. However, these positive effects are not constantly observed, probably because standardized procedures of environmental enrichment are lacking. Therefore, we engineered an enriched cage (the Marlau™ cage), which offers: (1) minimally stressful social interactions; (2) increased voluntary exercise; (3) multiple entertaining activities; (4) cognitive stimulation (maze exploration), and (5) novelty (maze configuration changed three times a week). The maze, which separates food pellet and water bottle compartments, guarantees cognitive stimulation for all animals. Compared to rats raised in groups in conventional cages, rats housed in Marlau™ cages exhibited increased cortical thickness, hippocampal neurogenesis and hippocampal levels of transcripts encoding various genes involved in tissue plasticity and remodeling. In addition, rats housed in Marlau™ cages exhibited better performances in learning and memory, decreased anxiety-associated behaviors, and better recovery of basal plasma corticosterone level after acute restraint stress. Marlau™ cages also insure inter-experiment reproducibility in spatial learning and brain gene expression assays. Finally, housing rats in Marlau™ cages after severe status epilepticus at weaning prevents the cognitive impairment observed in rats subjected to the same insult and then housed in conventional cages. By providing a standardized enriched environment for rodents during housing, the Marlau™ cage should facilitate the uniformity of environmental enrichment across laboratories.

Kouchi, Hayet Y.; Bodennec, Jacques; Morales, Anne; Georges, Beatrice; Bonnet, Chantal; Bouvard, Sandrine; Sloviter, Robert S.; Bezin, Laurent

2013-01-01

388

Stable learning of functional maps in self-organizing spiking neural networks with continuous synaptic plasticity.  

PubMed

This study describes a spiking model that self-organizes for stable formation and maintenance of orientation and ocular dominance maps in the visual cortex (V1). This self-organization process simulates three development phases: an early experience-independent phase, a late experience-independent phase and a subsequent refinement phase during which experience acts to shape the map properties. The ocular dominance maps that emerge accommodate the two sets of monocular inputs that arise from the lateral geniculate nucleus (LGN) to layer 4 of V1. The orientation selectivity maps that emerge feature well-developed iso-orientation domains and fractures. During the last two phases of development the orientation preferences at some locations appear to rotate continuously through ±180° along circular paths and referred to as pinwheel-like patterns but without any corresponding point discontinuities in the orientation gradient maps. The formation of these functional maps is driven by balanced excitatory and inhibitory currents that are established via synaptic plasticity based on spike timing for both excitatory and inhibitory synapses. The stability and maintenance of the formed maps with continuous synaptic plasticity is enabled by homeostasis caused by inhibitory plasticity. However, a prolonged exposure to repeated stimuli does alter the formed maps over time due to plasticity. The results from this study suggest that continuous synaptic plasticity in both excitatory neurons and interneurons could play a critical role in the formation, stability, and maintenance of functional maps in the cortex. PMID:23450808

Srinivasa, Narayan; Jiang, Qin

2013-02-27

389

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

390

Mental training as a tool in the neuroscientific study of brain and cognitive plasticity.  

PubMed

Although the adult brain was once seen as a rather static organ, it is now clear that the organization of brain circuitry is constantly changing as a function of experience or learning. Yet, research also shows that learning is often specific to the trained stimuli and task, and does not improve performance on novel tasks, even very similar ones. This perspective examines the idea that systematic mental training, as cultivated by meditation, can induce learning that is not stimulus or task specific, but process specific. Many meditation practices are explicitly designed to enhance specific, well-defined core cognitive processes. We will argue that this focus on enhancing core cognitive processes, as well as several general characteristics of meditation regimens, may specifically foster process-specific learning. To this end, we first define meditation and discuss key findings from recent neuroimaging studies of meditation. We then identify several characteristics of specific meditation training regimes that may determine process-specific learning. These characteristics include ongoing variability in stimulus input, the meta-cognitive nature of the processes trained, task difficulty, the focus on maintaining an optimal level of arousal, and the duration of training. Lastly, we discuss the methodological challenges that researchers face when attempting to control or characterize the multiple factors that may underlie meditation training effects. PMID:21347275

Slagter, Heleen A; Davidson, Richard J; Lutz, Antoine

2011-02-10

391

Functional diversity on synaptic plasticity mediated by endocannabinoids.  

PubMed

Endocannabinoids (eCBs) act as modulators of synaptic transmission through activation of a number of receptors, including, but not limited to, cannabinoid receptor 1 (CB1). eCBs share CB1 receptors as a common target with ?(9)-tetrahydrocannabinol (THC), the main psychoactive ingredient in marijuana. Although THC has been used for recreational and medicinal purposes for thousands of years, little was known about its effects at the cellular level or on neuronal circuits. Identification of CB1 receptors and the subsequent development of its specific ligands has therefore enhanced our ability to study and bring together a substantial amount of knowledge regarding how marijuana and eCBs modify interneuronal communication. To date, the eCB system, composed of cannabinoid receptors, ligands and the relevant enzymes, is recognized as the best-described retrograde signalling system in the brain. Its impact on synaptic transmission is widespread and more diverse than initially thought. The aim of this review is to succinctly present the most common forms of eCB-mediated modulation of synaptic transmission, while also illustrating the multiplicity of effects resulting from specializations of this signalling system at the circuital level. PMID:23108543

Cachope, Roger

2012-12-01

392

Enhancement of cognitive function in models of brain disease through environmental enrichment and physical activity.  

PubMed

This review will provide an overview of the non-drug based approaches that have been demonstrated to enhance cognitive function of the compromised brain, primarily focussed on the two most widely adopted paradigms of environmental enrichment and enhanced physical exercise. Environmental enrichment involves the generation of novelty and complexity in animal housing conditions which facilitates enhanced sensory and cognitive stimulation as well as physical activity. In a wide variety of animal models of brain disorders, environmental enrichment and exercise have been found to have beneficial effects, including cognitive enhancement, delayed disease onset, enhanced cellular plasticity and associated molecular processes. Potential cellular and molecular mechanisms will also be discussed, which have relevance for the future development of 'enviromimetics', drugs which could mimic or enhance the beneficial effects of environmental stimulation. This article is part of a Special Issue entitled 'Cognitive Enhancers'. PMID:22766390

Pang, Terence Y C; Hannan, Anthony J

2012-07-02

393

Neuroecology of cartilaginous fishes: the functional implications of brain scaling.  

PubMed

It is a widely accepted view that neural development can reflect morphological adaptations and sensory specializations. The aim of this review is to give a broad overview of the current status of brain data available for cartilaginous fishes and examine how perspectives on allometric scaling of brain size across this group of fishes has changed within the last 50 years with the addition of new data and more rigorous statistical analyses. The current knowledge of neuroanatomy in cartilaginous fishes is reviewed and data on brain size (encephalization, n = 151) and interspecific variation in brain organization (n = 84) has been explored to ascertain scaling relationships across this clade. It is determined whether similar patterns of brain organization, termed cerebrotypes, exist in species that share certain lifestyle characteristics. Clear patterns of brain organization exist across cartilaginous fishes, irrespective of phylogenetic grouping and, although this study was not a functional analysis, it provides further evidence that chondrichthyan brain structures might have developed in conjunction with specific behaviours or enhanced cognitive capabilities. Larger brains, with well-developed telencephala and large, highly foliated cerebella are reported in species that occupy complex reef or oceanic habitats, potentially identifying a reef-associated cerebrotype. In contrast, benthic and benthopelagic demersal species comprise the group with the smallest brains, with a relatively reduced telencephalon and a smooth cerebellar corpus. There is also evidence herein of a bathyal cerebrotype; deep-sea benthopelagic sharks possess relatively small brains and show a clear relative hypertrophy of the medulla oblongata. Despite the patterns observed and documented, significant gaps in the literature have been highlighted. Brain mass data are only currently available on c. 16% of all chondrichthyan species, and only 8% of species have data available on their brain organization, with far less on subsections of major brain areas that receive distinct sensory input. The interspecific variability in brain organization further stresses the importance of performing functional studies on a greater range of species. Only an expansive data set, comprised of species that span a variety of habitats and taxonomic groups, with widely disparate behavioural repertoires, combined with further functional analyses, will help shed light on the extent to which chondrichthyan brains have evolved as a consequence of behaviour, habitat and lifestyle in addition to phylogeny. PMID:22497414

Yopak, K E

2012-03-27

394

Behavioral manifestations of brain plasticity in blind and low-vision individuals.  

PubMed

Tactile sensitivity enhancement (TSE) observed in blind people is probably a result of intensified tactile training. Although many researchers consider TSE in the blind to be an example of use-dependent plasticity, it is unclear whether the effects of training (Braille reading) are specific, i.e. restricted to the trained function and hand, or if they are more general. To examine this issue further, blind Braille readers, low-vision subjects (Braille readers and non-Braille readers) and sighted controls were tested in two tasks: a texture task resembling the Braille system and a dissimilar groove orientation task. Braille readers, both blind and those with low vision, performed better in both tasks than low-vision non-Braille readers or sighted controls. However, the difference was significant only for the blind (more experienced) Braille readers. In the groove orientation task, the positive influence of training was detectable irrespective of the hand used in the test, but in the coarse texture task this influence was limited to the hand trained in Braille. Thus, it appears that tactile training is of significance in TSE but its effects are, to a large extent, task- and hand-specific. PMID:18389018

Jednoróg, Katarzyna; Grabowska, Anna

2008-01-01

395

Overview on the structure, composition, function, development, and plasticity of hippocampal dendritic spines  

Microsoft Academic Search

There has been an explosion of new information on the neurobiology of dendritic spines in synaptic signaling, integration, and plasticity. Novel imaging and analytical techniques have provided impor- tant new insights into dendritic spine structure and function. Results are accumulating across many disciplines, and a step toward consolidating some of this work has resulted in Dendritic Spines of the Hippocampus.

Karin E. Sorra; Kristen M. Harris

2000-01-01

396

The Plasticizer Di(2-ethylhexyl) Phthalate Modulates ??-Aminobutyric Acid Type A and Glycine Receptor Function  

Microsoft Academic Search

INTRODUCTION: Intravenous (IV) fluid bags made of polyvinyl chloride (PVC) often contain the plasticizer di(2-ethylhexyl) phthalate (DEHP) to make the PVC flexible. Phthalate esters have been reported to inhibit neuronal nicotinic acetylcholine receptors, which are sensitive to many inhaled anesthetics. This raises the possi- bility that DEHP might modulate the function of other cys-loop receptors, such as -amino butyric acid

Liya Yang; Pavle S. Milutinovic; Robert J. Brosnan; Edmond I Eger; James M. Sonner

2007-01-01

397

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

398

Cytochrome P450 in the brain: neuroendocrine functions.  

PubMed

The effectiveness of steroid hormone metabolites as sedatives and anesthetics has been known for many years. More recently, their interaction with neurotransmitter receptors has helped to elucidate their mechanism of action, but their physiological functions and their role in disturbances of behavior, anxiety, and sleep/wakefulness have yet to be elucidated. Until 1981 it was assumed that metabolites of steroid hormones arose from the adrenals and gonads and that their action on neurotransmitter receptors was a mechanism of communication between the brain and the periphery. The evidence that the brain could accumulate steroids independently of the adrenals and gonads in 1981 and later the evidence for the presence of the cholesterol side chain cleavage enzyme (P450scc) in the brain have challenged this concept and stimulated a great deal of interest in the possibility that the brain could be making its own steroids from cholesterol for some as yet undefined purpose. In this review we examine the data pertaining to the role of brain P450 in the synthesis and degradation of neurosteroids. We summarize the data on the presence of P450scc in the brain and try to answer the following questions: (1) Does P450scc in the brain contribute significantly to the synthesis of GABAA receptor active steroids? (2) Can the P450scc in the brain account for the accumulation of pregnenolone in the brain? (3) Is there evidence for special functions of the pregnenolone synthesized in the brain? (4) Is there a role for other forms of brain P450 in neurosteroid action? PMID:7556851

Warner, M; Gustafsson, J A

1995-07-01

399

Neuronal Plasticity in the Mammalian Brain: Relevance to Behavioral Learning and Memory  

ERIC Educational Resources Information Center

|Data suggesting that different brain circuits may underlie different forms of learning and memory are reviewed. Several current theories of learning and memory with respect to hippocampal and other brain circuit involvement are considered. (PCB)|

Teyler, Timothy J.; Fountain, Stephen B.

1987-01-01

400

The effects of working memory training on functional brain network efficiency.  

PubMed

The human brain is a highly interconnected network. Recent studies have shown that the functional and anatomical features of this network are organized in an efficient small-world manner that confers high efficiency of information processing at relatively low connection cost. However, it has been unclear how the architecture of functional brain networks is related to performance in working memory (WM) tasks and if these networks can be modified by WM training. Therefore, we conducted a double-blind training study enrolling 66 young adults. Half of the subjects practiced three WM tasks and were compared to an active control group practicing three tasks with low WM demand. High-density resting-state electroencephalography (EEG) was recorded before and after training to analyze graph-theoretical functional network characteristics at an intracortical level. WM performance was uniquely correlated with power in the theta frequency, and theta power was increased by WM training. Moreover, the better a person's WM performance, the more their network exhibited small-world topology. WM training shifted network characteristics in the direction of high performers, showing increased small-worldness within a distributed fronto-parietal network. Taken together, this is the first longitudinal study that provides evidence for the plasticity of the functional brain network underlying WM. PMID:23489778

Langer, Nicolas; von Bastian, Claudia C; Wirz, Helen; Oberauer, Klaus; Jäncke, Lutz

2013-01-31

401

Plasticity of functional connectivity in the adult spinal cord  

PubMed Central

This paper emphasizes several characteristics of the neural control of locomotion that provide opportunities for developing strategies to maximize the recovery of postural and locomotor functions after a spinal cord injury (SCI). The major points of this paper are: (i) the circuitry that controls standing and stepping is extremely malleable and reflects a continuously varying combination of neurons that are activated when executing stereotypical movements; (ii) the connectivity between neurons is more accurately perceived as a functional rather than as an anatomical phenomenon; (iii) the functional connectivity that controls standing and stepping reflects the physiological state of a given assembly of synapses, where the probability of these synaptic events is not deterministic; (iv) rather, this probability can be modulated by other factors such as pharmacological agents, epidural stimulation and/or motor training; (v) the variability observed in the kinematics of consecutive steps reflects a fundamental feature of the neural control system and (vi) machine-learning theories elucidate the need to accommodate variability in developing strategies designed to enhance motor performance by motor training using robotic devices after an SCI.

Cai, L.L; Courtine, G; Fong, A.J; Burdick, J.W; Roy, R.R; Edgerton, V.R

2006-01-01

402

ABCD: a functional database for the avian brain.  

PubMed

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

Schrott, Aniko; Kabai, Peter

2007-08-19

403

Potential of optical microangiography to monitor cerebral blood perfusion and vascular plasticity following traumatic brain injury in mice in vivo.  

PubMed

Optical microanglography (OMAG) is a recently developed imaging modality capable of volumetric imaging of dynamic blood perfusion, down to capillary level resolution, with an imaging depth up to 2.00 mm beneath the tissue surface. We report the use of OMAG to monitor the cerebral blood flow (CBF) over the cortex of mouse brain upon traumatic brain injury (TBI), with the cranium left intact, for a period of two weeks on the same animal. We show the ability of OMAG to repeatedly image 3-D cerebral vasculatures during pre- and post-traumatic phases, and to visualize the changes of regulated CBF and the vascular plasticity after TBI. The results indicate the potential of OMAG to explore the mechanism involved in the rehabilitation of TBI. PMID:19725710

Jia, Yali; Alkayed, Nabil; Wang, Ruikang K

404

Potential of optical microangiography to monitor cerebral blood perfusion and vascular plasticity following traumatic brain injury in mice in vivo  

NASA Astrophysics Data System (ADS)

Optical microanglography (OMAG) is a recently developed imaging modality capable of volumetric imaging of dynamic blood perfusion, down to capillary level resolution, with an imaging depth up to 2.00 mm beneath the tissue surface. We report the use of OMAG to monitor the cerebral blood flow (CBF) over the cortex of mouse brain upon traumatic brain injury (TBI), with the cranium left intact, for a period of two weeks on the same animal. We show the ability of OMAG to repeatedly image 3-D cerebral vasculatures during pre- and post-traumatic phases, and to visualize the changes of regulated CBF and the vascular plasticity after TBI. The results indicate the potential of OMAG to explore the mechanism involved in the rehabilitation of TBI.

Jia, Yali; Alkayed, Nabil; Wang, Ruikang K.

2009-07-01

405

Human brain functional MRI and DTI visualization with virtual reality  

PubMed Central

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

Chen, Bin; Moreland, John; Zhang, Jingyu

2011-01-01

406

Extraction, identification, and functional characterization of a bioactive substance from automated compound-handling plastic tips.  

PubMed

Disposable plastic labware is ubiquitous in contemporary pharmaceutical research laboratories. Plastic labware is routinely used for chemical compound storage and during automated liquid-handling processes that support assay development, high-throughput screening, structure-activity determinations, and liability profiling. However, there is little information available in the literature on the contaminants released from plastic labware upon DMSO exposure and their resultant effects on specific biological assays. The authors report here the extraction, by simple DMSO washing, of a biologically active substance from one particular size of disposable plastic tips used in automated compound handling. The active contaminant was identified as erucamide ((Z)-docos-13-enamide), a long-chain mono-unsaturated fatty acid amide commonly used in plastics manufacturing, by gas chromatography/mass spectroscopy analysis of the DMSO-extracted material. Tip extracts prepared in DMSO, as well as a commercially obtained sample of erucamide, were active in a functional bioassay of a known G-protein-coupled fatty acid receptor. A sample of a different disposable tip product from the same vendor did not release detectable erucamide following solvent extraction, and DMSO extracts prepared from this product were inactive in the receptor functional assay. These results demonstrate that solvent-extractable contaminants from some plastic labware used in the contemporary pharmaceutical research and development (R&D) environment can be introduced into physical and biological assays during routine compound management liquid-handling processes. These contaminants may further possess biological activity and are therefore a potential source of assay-specific confounding artifacts. PMID:19470712

Watson, John; Greenough, Emily B; Leet, John E; Ford, Michael J; Drexler, Dieter M; Belcastro, James V; Herbst, John J; Chatterjee, Moneesh; Banks, Martyn

2009-05-21

407

Postinjury Administration of l -Deprenyl Improves Cognitive Function and Enhances Neuroplasticity after Traumatic Brain Injury  

Microsoft Academic Search

The rat model of combined central fluid percussion traumatic brain injury (TBI) and bilateral entorhinal cortical lesion (BEC) produces profound, persistent cognitive deficits, sequelae associated with human TBI. In contrast to percussive TBI alone, this combined injury induces maladaptive hippocampal plasticity. Recent reports suggest a potential role for dopamine in CNS plasticity after trauma. We have examined the effect of

J. Zhu; R. J. Hamm; T. M. Reeves; J. T. Povlishock; L. L. Phillips

2000-01-01

408

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

409

The neural basis of functional brain imaging signals  

Microsoft Academic Search

The haemodynamic responses to neural activity that underlie the blood-oxygen-level-dependent (BOLD) signal used in functional magnetic resonance imaging (fMRI) of the brain are often assumed to be driven by energy use, particularly in presynaptic terminals or glia. However, recent work has suggested that most brain energy is used to power postsynaptic currents and action potentials rather than presynaptic or glial

David Attwell; Costantino Iadecola

2002-01-01

410

Structure and function of the blood–brain barrier  

Microsoft Academic Search

Neural signalling within the central nervous system (CNS) requires a highly controlled microenvironment. Cells at three key interfaces form barriers between the blood and the CNS: the blood–brain barrier (BBB), blood–CSF barrier and the arachnoid barrier. The BBB at the level of brain microvessel endothelium is the major site of blood–CNS exchange. The structure and function of the BBB is

N. Joan Abbott; Adjanie A. K. Patabendige; Diana E. M. Dolman; Siti R. Yusof; David J. Begley

2010-01-01

411

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

412

Investigating brain dynamics and connectivity with functional MRI  

Microsoft Academic Search

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

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

2004-01-01

413

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

414

Functional brain imaging of nicotinic effects on higher cognitive processes  

Microsoft Academic Search

Significant advances in human functional brain imaging offer new opportunities for direct observation of the effects of nicotine, novel nicotinic agonists and nicotinic antagonists on human cognitive and behavioral performance. Careful research over the last decade has enabled investigators to explore the role of nicotinic systems on the functional neuroanatomy and neural circuitry of cognitive tasks in domains such as

Paul A. Newhouse; Alexandra S. Potter; Julie A. Dumas; Christiane M. Thiel

2011-01-01

415

Imaging Body Structure and Mapping Brain Function: A Historical Approach  

Microsoft Academic Search

Now in its second decade, functional magnetic resonance imaging (fMRI) localizes changes in blood oxygenation that occur in the brain when an individual performs a mental task. Physicians and scientists use fMRI not only to map sensory, motor, and cognitive functions, but also to study the neural correlates of a range of sensitive and potentially stigmatizing conditions, behaviors, and characteristics.

Stacey A. Tovino

2007-01-01

416

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

417

Altered Sleep Brain Functional Connectivity in Acutely Depressed Patients  

Microsoft Academic Search

Recent evidence suggests that problems in information processing within neural networks may underlie depressive disease. In this study, we investigated whether sleep functional brain net- works are abnormally organized during a major depressive episode (MDE). We characterized spatial patterns of functional connectivity by computing the ''synchronization likelihood'' (SL) of 19 sleep EEG channels in 11 acutely depressed patients (42 (20-51)

Samuël J. J. Leistedt; Nathalie Coumans; Martine Dumont; Jean-Pol Lanquart; Cornelis J. Stam; Paul Linkowski

2009-01-01

418

Executive Functioning and Adaptive Living Skills after Acquired Brain Injury  

Microsoft Academic Search

Executive dysfunction is common following brain injury, with impairments involving attention, social pragmatics, higher-order thinking, judgment, and reasoning. Executive function impairments may have a direct impact on an individual's ability to return to instrumental activities of daily living (IADL), including employment, money management, driving, and maintaining a residence. Research has shown that neuropsychological executive function measures may be able to

Robert Perna; Ashlee R. Loughan; Kristin Talka

2012-01-01

419

Functional Brain Imaging of Nicotinic Effects on Higher Cognitive Processes  

PubMed Central

Significant advances in human functional brain imaging offer new opportunities for direct observation of the effects of nicotine, novel nicotinic agonists and nicotinic antagonists on human cognitive and behavioral performance. Careful research over the last decade has enabled investigators to explore the role of nicotinic systems on the functional neuroanatomy and neural circuitry of cognitive tasks in domains such as selective attention, working memory, episodic memory, cognitive control, and emotional processing. In addition, recent progress in understanding functional connectivity between brain regions utilized during cognitive and emotional processes offers new opportunities for examining drug effects on network-related activity. This review will critically summarize available nicotinic functional brain imaging studies focusing on the specific cognitive domains of attention, memory, behavioral control, and emotional processing. Generally speaking, nicotine appears to increase task-related activity in non-smokers and deprived smokers, but not active smokers. By contrast, nicotine or nicotinic stimulation decreases the activity of structures associated with the default mode network. These particular patterns of activation and/or deactivation may be useful for early drug development and may be an efficient and cost-effective method of screening potential nicotinic agents. Further studies will have to be done to clarify whether such activity changes correlate with cognitive or affective outcomes that are clinically relevant. The use of functional brain imaging will be a key tool for probing pathologic changes related to brain illness and for nicotinic drug development.

Newhouse, Paul A.; Potter, Alexandra S.; Dumas, Julie A.; Thiel, Christiane M.

2011-01-01

420

Resting-State Brain Organization Revealed by Functional Covariance Networks  

PubMed Central

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

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

2011-01-01

421

Wherefore art thou, homeo(stasis)? Functional diversity in homeostatic synaptic plasticity.  

PubMed

Homeostatic plasticity has emerged as a fundamental regulatory principle that strives to maintain neuronal activity within optimal ranges by altering diverse aspects of neuronal function. Adaptation to network activity is often viewed as an essential negative feedback restraint that prevents runaway excitation or inhibition. However, the precise importance of these homeostatic functions is often theoretical rather than empirically derived. Moreover, a remarkable multiplicity of homeostatic adaptations has been observed. To clarify these issues, it may prove useful to ask: why do homeostatic mechanisms exist, what advantages do these adaptive responses confer on a given cell population, and why are there so many seemingly divergent effects? Here, we approach these questions by applying the principles of control theory to homeostatic synaptic plasticity of mammalian neurons and suggest that the varied responses observed may represent distinct functional classes of control mechanisms directed toward disparate physiological goals. PMID:22685679

Queenan, Bridget N; Lee, Kea Joo; Pak, Daniel T S

2012-05-17

422

The Strength of Plastic Bonded Explosives as a Function of Pressure, Strain Rate and Temperature  

NASA Astrophysics Data System (ADS)

Measurements as a function of strain rate and temperature have indicated the importance of the polymer binder in determining the strength of plastic bonded explosives at ambient conditions and low strain rate. Recent measurements of strength as a function of pressure further support this conclusion. As pressure or strain rate are increased or temperature is decreased the strength increases as does the strength of many polymers. In addition, at relatively large values of pressure or strain rate and/or relatively low values of temperature the strength is less sensitive to changes of these quantities. These trends suggest that as the polymer binder becomes stronger with increasing pressure or strain rate or with decreasing temperature, the strength of the explosive component of these composites becomes more important in determining the strength of the composite. Results will be presented for plastic bonded explosives, e.g., LX-14, that demonstrate these trends as a function of pressure, strain rate and temperature.

Wiegand, Donald

2005-07-01

423

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)

1995-05-01

424

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

PubMed

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

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

2012-01-01

425

Organization of Cognitive Functions in the Brain.  

ERIC Educational Resources Information Center

Neuropsychological research on the effects of hemispherectomy-the excision of one of the cerebral hemispheres-in children and adults adds to knowledge about the division of labor between the left cerebral hemisphere, which specializes in language and verbal cognitive functions, and the right hemisphere, which specializes in nonlanguage functions.…

Smith, Aaron

426

Effects of plasticizers and their mixtures on estrogen receptor and thyroid hormone functions.  

PubMed

Plasticizers are additives used to increase the flexibility or plasticity of the material to which they are added, normally rigid plastic and as additives in paint and adhesives. They are suspected to interfere with the endocrine system, including the estrogen and the thyroid hormone (TH) systems. We investigated in vitro the thyroid hormone-like and estrogenic activities of a range of widely used plasticizers and phenols including benzyl butyl phthalate (BBP), dibutyl phthalate (DBP), dioctyl phthalate (DOP), diisodecyl phthalate (DIDP), diisononyl phthalate (DINP), di(2-ethylhexyl) phthalate (DEHP), bis(2-ethylhexyl) adipate (DEHA), 4-tert-octylphenol (tOP), 4-chloro-3-methylphenol (CMP), 2,4-dichlorophenol (2,4-DCP), 2-phenylphenol (2-PP) and resorcinol. The TH disrupting potential was determined by the effect on the TH-dependent rat pituitary GH3 cell proliferation (T-screen). The estrogenic activities of the compounds were assessed in MVLN cells, stably transfected with an estrogen receptor (ER) luciferase reporter vector. Furthermore, the combined effect of a multi-components mixture of six plasticizers was evaluated for its estrogenic and TH-like activities. All the tested compounds, but 2-PP, significantly affected the GH3 cell proliferation. tOP, BBP and DBP activated ER transactivity, whereas DEHP antagonized the 17beta-estradiol induced ER function. The mixture significantly induced ER transactivity in an additive manner, whereas in the T-screen, the observed mixture effect was lower than predicted, suggesting a potential antagonizing effect of the mixture. In conclusion, the tested plasticizers and phenols elicited endocrine-disrupting potential that can be mediated via interference with the estrogen and TH systems. Moreover, the observed mixture effect stresses the importance of considering the combined effect of the compounds for risk assessment of human health. PMID:19463926

Ghisari, Mandana; Bonefeld-Jorgensen, Eva Cecilie

2009-05-20

427

Decreased Functional Brain Connectivity in Adolescents with Internet Addiction  

PubMed Central

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