Sample records for functional brain plasticity

  1. Integrated technology for evaluation of brain function and neural plasticity.

    PubMed

    Rossini, Paolo M; Dal Forno, Gloria

    2004-02-01

    The study of neural plasticity has expanded rapidly in the past decades and has shown the remarkable ability of the developing, adult, and aging brain to be shaped by environmental inputs in health and after a lesion. Robust experimental evidence supports the hypothesis that neuronal aggregates adjacent to a lesion in the sensorimotor brain areas can take over progressively the function previously played by the damaged neurons. It definitely is accepted that such a reorganization modifies sensibly the interhemispheric differences in somatotopic organization of the sensorimotor cortices. This reorganization largely subtends clinical recovery of motor performances and sensorimotor integration after a stroke. Brain functional imaging studies show that recovery from hemiplegic strokes is associated with a marked reorganization of the activation patterns of specific brain structures. To regain hand motor control, the recovery process tends over time to bring the bilateral motor network activation toward a more normal intensity/extent, while overrecruiting simultaneously new areas, perhaps to sustain this process. Considerable intersubject variability exists in activation/hyperactivation pattern changes over time. Some patients display late-appearing dorsolateral prefrontal cortex activation, suggesting the development of "executive" strategies to compensate for the lost function. The AH in stroke often undergoes a significant "remodeling" of sensory and motor hand somatotopy outside the "normal" areas, or enlargement of the hand representation. The UH also undergoes reorganization, although to a lesser degree. Although absolute values of the investigated parameters fluctuate across subjects, secondary to individual anatomic variability, variation is minimal with regards to interhemispheric differences, due to the fact that individual morphometric characters are mirrored in the two hemispheres. Excessive interhemispheric asymmetry of the sensorimotor hand areas seems to be the parameter with highest sensitivity in describing brain reorganization after a monohemispheric lesion, and mapping motor and somatosensory cortical areas through focal TMS, fMRI, PET, EEG, and MEG is useful in studying hand representation and interhemispheric asymmetries in normal and pathologic conditions. TMS and MEG allow the detection of sensorimotor areas reshaping, as a result of either neuronal reorganization or recovery of the previously damaged neural network. These techniques have the advantage of high temporal resolution but also have limitations. TMS provides only bidimensional scalp maps, whereas MEG, even if giving three-dimensional mapping of generator sources, does so by means of inverse procedures that rely on the choice of a mathematical model of the head and the sources. These techniques do not test movement execution and sensorimotor integration as used in everyday life. fMRI and PET may provide the ideal means to integrate the findings obtained with the other two techniques. This multitechnology combined approach is at present the best way to test the presence and amount of plasticity phenomena underlying partial or total recovery of several functions, sensorimotor above all. Dynamic patterns of recovery are emerging progressively from the relevant literature. Enhanced recruitment of the affected cortex, be it spared perilesional tissue, as in the case of cortical stroke, or intact but deafferented cortex, as in subcortical strokes, seems to be the rule, a mechanism especially important in early postinsult stages. The transfer over time of preferential activation toward contralesional cortices, as observed in some cases, seems, however, to reflect a less efficient type of plastic reorganization, with some aspects of maladaptive plasticity. Reinforcing the use of the affected side can cause activation to increase again in the affected side with a corresponding enhancement of clinical function. Activation of the UH MI may represent recruitment of direct (uncrossed) corticospinal tracts and relate more to mi

  2. Brain plasticity and behavior.

    PubMed

    Kolb, B; Whishaw, I Q

    1998-01-01

    Brain plasticity refers to the brain's ability to change structure and function. Experience is a major stimulant of brain plasticity in animal species as diverse as insects and humans. It is now clear that experience produces multiple, dissociable changes in the brain including increases in dendritic length, increases (or decreases) in spine density, synapse formation, increased glial activity, and altered metabolic activity. These anatomical changes are correlated with behavioral differences between subjects with and without the changes. Experience-dependent changes in neurons are affected by various factors including aging, gonadal hormones, trophic factors, stress, and brain pathology. We discuss the important role that changes in dendritic arborization play in brain plasticity and behavior, and we consider these changes in the context of changing intrinsic circuitry of the cortex in processes such as learning. PMID:9496621

  3. Imaging brain plasticity after trauma

    PubMed Central

    Kou, Zhifeng; Iraji, Armin

    2014-01-01

    The brain is highly plastic after stroke or epilepsy; however, there is a paucity of brain plasticity investigation after traumatic brain injury (TBI). This mini review summarizes the most recent evidence of brain plasticity in human TBI patients from the perspective of advanced magnetic resonance imaging. Similar to other forms of acquired brain injury, TBI patients also demonstrated both structural reorganization as well as functional compensation by the recruitment of other brain regions. However, the large scale brain network alterations after TBI are still unknown, and the field is still short of proper means on how to guide the choice of TBI rehabilitation or treatment plan to promote brain plasticity. The authors also point out the new direction of brain plasticity investigation. PMID:25206874

  4. Sex hormone therapy and functional brain plasticity in postmenopausal women

    Microsoft Academic Search

    U. Bayer; M. Hausmann

    2011-01-01

    Several studies have shown that fluctuating levels of sex hormones (estrogen and progesterone) can affect fundamental principles of brain organization, including functional cerebral asymmetries (FCAs) and interhemispheric interactions. The majority of findings come from studies investigating younger women tested during distinct hormonal phases of the menstrual cycle, an approach that does not necessarily allow for conclusions about the causal relationship

  5. Music drives brain plasticity

    PubMed Central

    2009-01-01

    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. PMID:20948610

  6. Musical training as a framework for brain plasticity: behavior, function, and structure.

    PubMed

    Herholz, Sibylle C; Zatorre, Robert J

    2012-11-01

    Musical training has emerged as a useful framework for the investigation of training-related plasticity in the human brain. Learning to play an instrument is a highly complex task that involves the interaction of several modalities and higher-order cognitive functions and that results in behavioral, structural, and functional changes on time scales ranging from days to years. While early work focused on comparison of musical experts and novices, more recently an increasing number of controlled training studies provide clear experimental evidence for training effects. Here, we review research investigating brain plasticity induced by musical training, highlight common patterns and possible underlying mechanisms of such plasticity, and integrate these studies with findings and models for mechanisms of plasticity in other domains. PMID:23141061

  7. Functional and Structural Brain Plasticity Enhanced by Motor and Cognitive Rehabilitation in Multiple Sclerosis

    PubMed Central

    Prosperini, Luca; Piattella, Maria Cristina

    2015-01-01

    Rehabilitation is recognized to be important in ameliorating motor and cognitive functions, reducing disease burden, and improving quality of life in patients with multiple sclerosis (MS). In this systematic review, we summarize the existing evidences that motor and cognitive rehabilitation may enhance functional and structural brain plasticity in patients with MS, as assessed by means of the most advanced neuroimaging techniques, including diffusion tensor imaging and task-related and resting-state functional magnetic resonance imaging (MRI). In most cases, the rehabilitation program was based on computer-assisted/video game exercises performed in either an outpatient or home setting. Despite their heterogeneity, all the included studies describe changes in white matter microarchitecture, in task-related activation, and/or in functional connectivity following both task-oriented and selective training. When explored, relevant correlation between improved function and MRI-detected brain changes was often found, supporting the hypothesis that training-induced brain plasticity is specifically linked to the trained domain. Small sample sizes, lack of randomization and/or an active control group, as well as missed relationship between MRI-detected changes and clinical performance, are the major drawbacks of the selected studies. Knowledge gaps in this field of research are also discussed to provide a framework for future investigations. PMID:26064692

  8. Differential pattern of functional brain plasticity after compassion and empathy training.

    PubMed

    Klimecki, Olga M; Leiberg, Susanne; Ricard, Matthieu; Singer, Tania

    2014-06-01

    Although empathy is crucial for successful social interactions, excessive sharing of others' negative emotions may be maladaptive and constitute a source of burnout. To investigate functional neural plasticity underlying the augmentation of empathy and to test the counteracting potential of compassion, one group of participants was first trained in empathic resonance and subsequently in compassion. In response to videos depicting human suffering, empathy training, but not memory training (control group), increased negative affect and brain activations in anterior insula and anterior midcingulate cortex-brain regions previously associated with empathy for pain. In contrast, subsequent compassion training could reverse the increase in negative effect and, in contrast, augment self-reports of positive affect. In addition, compassion training increased activations in a non-overlapping brain network spanning ventral striatum, pregenual anterior cingulate cortex and medial orbitofrontal cortex. We conclude that training compassion may reflect a new coping strategy to overcome empathic distress and strengthen resilience. PMID:23576808

  9. Differential pattern of functional brain plasticity after compassion and empathy training

    PubMed Central

    Leiberg, Susanne; Ricard, Matthieu; Singer, Tania

    2014-01-01

    Although empathy is crucial for successful social interactions, excessive sharing of others’ negative emotions may be maladaptive and constitute a source of burnout. To investigate functional neural plasticity underlying the augmentation of empathy and to test the counteracting potential of compassion, one group of participants was first trained in empathic resonance and subsequently in compassion. In response to videos depicting human suffering, empathy training, but not memory training (control group), increased negative affect and brain activations in anterior insula and anterior midcingulate cortex—brain regions previously associated with empathy for pain. In contrast, subsequent compassion training could reverse the increase in negative effect and, in contrast, augment self-reports of positive affect. In addition, compassion training increased activations in a non-overlapping brain network spanning ventral striatum, pregenual anterior cingulate cortex and medial orbitofrontal cortex. We conclude that training compassion may reflect a new coping strategy to overcome empathic distress and strengthen resilience. PMID:23576808

  10. Brain functional plasticity associated with the emergence of expertise in extreme language control.

    PubMed

    Hervais-Adelman, Alexis; Moser-Mercer, Barbara; Golestani, Narly

    2015-07-01

    We used functional magnetic resonance imaging (fMRI) to longitudinally examine brain plasticity arising from long-term, intensive simultaneous interpretation training. Simultaneous interpretation is a bilingual task with heavy executive control demands. We compared brain responses observed during simultaneous interpretation with those observed during simultaneous speech repetition (shadowing) in a group of trainee simultaneous interpreters, at the beginning and at the end of their professional training program. Age, sex and language-proficiency matched controls were scanned at similar intervals. Using multivariate pattern classification, we found distributed patterns of changes in functional responses from the first to second scan that distinguished the interpreters from the controls. We also found reduced recruitment of the right caudate nucleus during simultaneous interpretation as a result of training. Such practice-related change is consistent with decreased demands on multilingual language control as the task becomes more automatized with practice. These results demonstrate the impact of simultaneous interpretation training on the brain functional response in a cerebral structure that is not specifically linguistic, but that is known to be involved in learning, in motor control, and in a variety of domain-general executive functions. Along with results of recent studies showing functional and structural adaptations in the caudate nuclei of experts in a broad range of domains, our results underline the importance of this structure as a central node in expertise-related networks. PMID:25869858

  11. Psychotherapy and brain plasticity

    PubMed Central

    Collerton, Daniel

    2013-01-01

    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. PMID:24046752

  12. Brain Plasticity and Behaviour in the Developing Brain

    PubMed Central

    Kolb, Bryan; Gibb, Robbin

    2011-01-01

    Objective: To review general principles of brain development, identify basic principles of brain plasticity, and discuss factors that influence brain development and plasticity. Method: A literature review of relevant English-language manuscripts on brain development and plasticity was conducted. Results: Brain development progresses through a series of stages beginning with neurogenesis and progressing to neural migration, maturation, synaptogenesis, pruning, and myelin formation. Eight basic principles of brain plasticity are identified. Evidence that brain development and function is influenced by different environmental events such as sensory stimuli, psychoactive drugs, gonadal hormones, parental-child relationships, peer relationships, early stress, intestinal flora, and diet. Conclusions: The development of the brain reflects more than the simple unfolding of a genetic blueprint but rather reflects a complex dance of genetic and experiential factors that shape the emerging brain. Understanding the dance provides insight into both normal and abnormal development. PMID:22114608

  13. Using brain-computer interfaces to induce neural plasticity and restore function

    NASA Astrophysics Data System (ADS)

    Grosse-Wentrup, Moritz; Mattia, Donatella; Oweiss, Karim

    2011-04-01

    Analyzing neural signals and providing feedback in realtime is one of the core characteristics of a brain-computer interface (BCI). As this feature may be employed to induce neural plasticity, utilizing BCI technology for therapeutic purposes is increasingly gaining popularity in the BCI community. In this paper, we discuss the state-of-the-art of research on this topic, address the principles of and challenges in inducing neural plasticity by means of a BCI, and delineate the problems of study design and outcome evaluation arising in this context. We conclude with a list of open questions and recommendations for future research in this field.

  14. New concepts in surgery of WHO grade II gliomas: functional brain mapping, connectionism and plasticity--a review.

    PubMed

    Duffau, Hugues

    2006-08-01

    Despite a recent literature supporting the impact of surgery on the natural history of low-grade glioma (LGG), the indications of resection still remain a matter of debate, especially because of the frequent location of these tumors within eloquent brain areas - thus with a risk to induce a permanent postoperative deficit. Therefore, since the antagonist nature of this surgery is to perform the most extensive glioma removal possible, while preserving the function and the quality of life, new concepts were recently applied to LGG resection in order to optimize the benefit/risk ratio of the surgery.First, due to the development of functional mapping methods, namely perioperative neurofunctional imaging and intrasurgical direct electrical stimulation, the study of cortical functional organization is currently possible for each patient - in addition to an extensive neuropsychological assessment. Such knowledge is essential because of the inter-individual anatomo-functional variability, increased in tumors due to cerebral plasticity phenomena. Thus, brain mapping enables to envision and perform a resection according to individual functional boundaries.Second, since LGG invades not only cortical but also subcortical structures, and shows an infiltrative progression along the white matter tracts, new techniques of anatomical tracking and functional mapping of the subcortical white matter pathways were also used with the goal to study the individual effective connectivity - which needs imperatively to be preserved during the resection.Third, the better understanding of brain plasticity mechanisms, induced both by the slow-growing LGG and by the surgery itself, were equally studied in each patient and applied to the surgical strategy by incorporating individual dynamic potential of reorganization into the operative planning. The integration of these new concepts of individual functional mapping, connectivity and plastic potential to the surgery of LGG has allowed an extent of surgical indications, an optimization of the quality of resection (neuro-oncological benefit), and a minimization of the risk of sequelae (benefit on the quality of life). In addition, such a strategy has also fundamental applications, since it represents a new door to the connectionism and cerebral plasticity. PMID:16607477

  15. Brain Plasticity and fMRI

    Microsoft Academic Search

    B. Thomas; C. Sage; M. Eyssen; S. Kovacs; R. Peeters; S. Sunaert

    Plasticity is the collective term used for a number of mechanisms that lead to molecular and\\/or structural alterations of\\u000a an organism. These changes occur throughout life during learning processes, novel experiences as well as in response to injury.\\u000a This chapter consists of a review of functional magnetic resonance imaging findings on plasticity phenomena occurring in response\\u000a to brain injury, epilepsy,

  16. Mechanistic basis and functional roles of long-term plasticity in auditory neurons induced by a brain-generated estrogen.

    PubMed

    Tremere, Liisa A; Kovaleski, Ryan F; Burrows, Kaiping; Jeong, Jin Kwon; Pinaud, Raphael

    2012-11-14

    The classic estrogen 17?-estradiol (E2) was recently identified as a novel modulator of hearing function. It is produced rapidly, in an experience-dependent fashion, by auditory cortical neurons of both males and females. This brain-generated E2 enhances the efficiency of auditory coding and improves the neural and behavioral discrimination of auditory cues. Remarkably, the effects of E2 are long-lasting and persist for hours after local rises in hormone levels have subsided. The mechanisms and functional consequences of this E2-induced plasticity of auditory responses are unknown. Here, we addressed these issues in the zebra finch model by combining intracerebral pharmacology, biochemical assays, in vivo neurophysiology in awake animals, and computational and information theoretical approaches. We show that auditory experience activates the MAPK pathway in an E2-dependent manner. This effect is mediated by estrogen receptor ? (ER?), which directly associates with MEKK1 to sequentially modulate MEK and ERK activation, where the latter is required for the engagement of downstream molecular targets. We further show that E2-mediated activation of the MAPK cascade is required for the long-lasting enhancement of auditory-evoked responses in the awake brain. Moreover, a functional consequence of this E2/MAPK activation is to sustain enhanced information handling and neural discrimination by auditory neurons for several hours following hormonal challenge. Our results demonstrate that brain-generated E2 engages, via a nongenomic interaction between an estrogen receptor and a kinase, a persistent form of experience-dependent plasticity that enhances the neural coding and discrimination of behaviorally relevant sensory signals in the adult vertebrate brain. PMID:23152630

  17. Brain plasticity in health and disease.

    PubMed

    Johansson, Barbro B

    2004-12-01

    Research during the last decades has greatly increased our understanding of brain plasticity, i.e. how neuronal circuits can be modified by experience, learning and in response to brain lesions. Currently available neuroimaging techniques that make it possible to study the function of the human brain in vivo have had an important impact. Cross-modal plasticity during development is demonstrated by cortical reorganization in blind or deaf children. Early musical training has lasting effects in shaping the brain. Albeit the plasticity is largest during childhood, the adult brain retains a capacity for functional and structural reorganization that earlier has been underestimated. Recent research on Huntington's disease has revealed the possibility of environmental interaction even with dominant genes. Scientifically based training methods are now being applied in rehabilitation of patients after stroke and trauma, and in the sensory retraining techniques currently applied in the treatment of focal hand dystonia as well as in sensory re-education after nerve repair in hand surgery. There is evidence that frequent participation in challenging and stimulating activities is associated with reduced cognitive decline during aging. The current concept of brain plasticity has wide implication for areas outside neuroscience and for all human life. PMID:15647628

  18. Augmentation-related brain plasticity

    PubMed Central

    Di Pino, Giovanni; Maravita, Angelo; Zollo, Loredana; Guglielmelli, Eugenio; Di Lazzaro, Vincenzo

    2014-01-01

    Today, the anthropomorphism of the tools and the development of neural interfaces require reconsidering the concept of human-tools interaction in the framework of human augmentation. This review analyses the plastic process that the brain undergoes when it comes into contact with augmenting artificial sensors and effectors and, on the other hand, the changes that the use of external augmenting devices produces in the brain. Hitherto, few studies investigated the neural correlates of augmentation, but clues on it can be borrowed from logically-related paradigms: sensorimotor training, cognitive enhancement, cross-modal plasticity, sensorimotor functional substitution, use and embodiment of tools. Augmentation modifies function and structure of a number of areas, i.e., primary sensory cortices shape their receptive fields to become sensitive to novel inputs. Motor areas adapt the neuroprosthesis representation firing-rate to refine kinematics. As for normal motor outputs, the learning process recruits motor and premotor cortices and the acquisition of proficiency decreases attentional recruitment, focuses the activity on sensorimotor areas and increases the basal ganglia drive on the cortex. Augmentation deeply relies on the frontoparietal network. In particular, premotor cortex is involved in learning the control of an external effector and owns the tool motor representation, while the intraparietal sulcus extracts its visual features. In these areas, multisensory integration neurons enlarge their receptive fields to embody supernumerary limbs. For operating an anthropomorphic neuroprosthesis, the mirror system is required to understand the meaning of the action, the cerebellum for the formation of its internal model and the insula for its interoception. In conclusion, anthropomorphic sensorized devices can provide the critical sensory afferences to evolve the exploitation of tools through their embodiment, reshaping the body representation and the sense of the self. PMID:24966816

  19. Augmentation-related brain plasticity.

    PubMed

    Di Pino, Giovanni; Maravita, Angelo; Zollo, Loredana; Guglielmelli, Eugenio; Di Lazzaro, Vincenzo

    2014-01-01

    Today, the anthropomorphism of the tools and the development of neural interfaces require reconsidering the concept of human-tools interaction in the framework of human augmentation. This review analyses the plastic process that the brain undergoes when it comes into contact with augmenting artificial sensors and effectors and, on the other hand, the changes that the use of external augmenting devices produces in the brain. Hitherto, few studies investigated the neural correlates of augmentation, but clues on it can be borrowed from logically-related paradigms: sensorimotor training, cognitive enhancement, cross-modal plasticity, sensorimotor functional substitution, use and embodiment of tools. Augmentation modifies function and structure of a number of areas, i.e., primary sensory cortices shape their receptive fields to become sensitive to novel inputs. Motor areas adapt the neuroprosthesis representation firing-rate to refine kinematics. As for normal motor outputs, the learning process recruits motor and premotor cortices and the acquisition of proficiency decreases attentional recruitment, focuses the activity on sensorimotor areas and increases the basal ganglia drive on the cortex. Augmentation deeply relies on the frontoparietal network. In particular, premotor cortex is involved in learning the control of an external effector and owns the tool motor representation, while the intraparietal sulcus extracts its visual features. In these areas, multisensory integration neurons enlarge their receptive fields to embody supernumerary limbs. For operating an anthropomorphic neuroprosthesis, the mirror system is required to understand the meaning of the action, the cerebellum for the formation of its internal model and the insula for its interoception. In conclusion, anthropomorphic sensorized devices can provide the critical sensory afferences to evolve the exploitation of tools through their embodiment, reshaping the body representation and the sense of the self. PMID:24966816

  20. Memory and Consciousness Plasticity, Brain Rhythms

    E-print Network

    Kersting, Roland

    Memory and Consciousness Plasticity, Brain Rhythms and Sleep Summer School 2014 and Consciousness ­ Plasticity, Brain Rhythms and Sleep" is organized by young researchers of the Department of Medical Psychology and Behavioral Neurobiology of the University of Tübingen, headed by Jan

  1. Ben's Plastic Brain

    ERIC Educational Resources Information Center

    Kaplan, Susan L.

    2010-01-01

    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…

  2. Brain plasticity in the adult: modulation of function in amblyopia with rTMS.

    PubMed

    Thompson, Benjamin; Mansouri, Behzad; Koski, Lisa; Hess, Robert F

    2008-07-22

    Amblyopia is a cortically based visual disorder caused by disruption of vision during a critical early developmental period. It is often thought to be a largely intractable problem in adult patients because of a lack of neuronal plasticity after this critical period [1]; however, recent advances have suggested that plasticity is still present in the adult amblyopic visual cortex [2-6]. Here, we present data showing that repetitive transcranial magnetic stimulation (rTMS) of the visual cortex can temporarily improve contrast sensitivity in the amblyopic visual cortex. The results indicate continued plasticity of the amblyopic visual system in adulthood and open the way for a potential new therapeutic approach to the treatment of amblyopia. PMID:18635353

  3. Searching for the principles of brain plasticity and behavior.

    PubMed

    Kolb, Bryan; Gibb, Robbin

    2014-09-01

    An important development in behavioral neuroscience in the past 25 years has been the demonstration that the brain is far more flexible in structure and function than was previously believed. Studies of laboratory animals have provided an important tool for understanding the nature of brain plasticity and behavior at many levels ranging from detailed behavioral paradigms, electrophysiology, neuronal morphology, protein chemistry, and epigenetics. Here we seek a synthesis of the multidisciplinary work on brain plasticity and behavior to identify some general principles on how the brain changes in response to a wide range of experiences over the lifetime. PMID:24457097

  4. Plasticity of Language-Related Brain Function During Recovery from Stroke

    E-print Network

    to correlate functional recovery from aphasia after acute stroke with the temporal evolution of the anatomic during recovery from acute stroke presenting with aphasia. Perfusion, diffusion, sodium, and conventional patient, in whom mapping was performed fortuitously before stroke, recovery of a Wernicke's aphasia showed

  5. Brain plasticity, sleep and aging.

    PubMed

    Cirelli, Chiara

    2012-01-01

    The link between sleep and aging is a hot topic of research. On the one hand, much attention has been paid to epidemiological studies showing that both short sleep and long sleep in humans are associated with reduced longevity. I will briefly review this literature and discuss recent experiments in the fruit fly Drosophila melanogaster that may contribute to understanding this complicated association. On the other hand, other experiments have focused on age-related sleep changes. Sleep quantity and quality tend to decrease with age, but the underlying mechanisms remain unclear. In young subjects, converging evidence from human and animal studies shows that the need for sleep is strongly modulated by the amount of brain plasticity during prior wake. In short, the more we learn and adapt our brain to an ever-changing environment, the more we need to sleep. If so, poor sleep in the elderly could be caused by a chronic decrease in sleep need due to reduced opportunity to learn and be exposed to novel experiences, rather than, or in addition to, an intrinsic problem in the neural circuits responsible for sleep regulation. This distinction has obvious practical implications. However, very little research has been done on this topic. PMID:22398514

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

    SciTech Connect

    Anderson, Matthew; Hooker, Brian S.; Herbert, Martha

    2008-01-01

    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 with a high metabolic demand such as the central nervous system, the continued use of mitochondria with DNA damage may generate additional ROS which will activate the innate immune system leading to more ROS production. Such a mechanism would self-sustain and possibly progressively worsen. The mitochondrial dysfunction and altered redox signal transduction pathways found in autism would conspire to activate both astroglia and microglia. These activated cells can then initiate a broad-spectrum proinflammatory gene response. Neurons may have acquired receptors for these inflammatory signals to inhibit neuronal signaling as a protection from excitotoxic damage during various pathologic insults (e.g., infection). In autism, over-zealous neuroinflammatory responses could not only influence neural developmental processes, but may more significantly impair neural signaling involved in cognition in an ongoing fashion. This model makes specific predictions in patients and experimental animal models and suggests a number of targets sites of intervention. Our model of potentially reversible pathophysiological mechanisms in autism motivates our hope that effective therapies may soon appear on the horizon.

  7. Hearing colors: an example of brain plasticity

    PubMed Central

    Alfaro, Arantxa; Bernabeu, Ángela; Agulló, Carlos; Parra, Jaime; Fernández, Eduardo

    2015-01-01

    Sensory substitution devices (SSDs) are providing new ways for improving or replacing sensory abilities that have been lost due to disease or injury, and at the same time offer unprecedented opportunities to address how the nervous system could lead to an augmentation of its capacities. In this work we have evaluated a color-blind subject using a new visual-to-auditory SSD device called “Eyeborg”, that allows colors to be perceived as sounds. We used a combination of neuroimaging techniques including Functional Magnetic Resonance Imaging (fMRI), Diffusion Tensor Imaging (DTI) and proton Magnetic Resonance Spectroscopy (1H-MRS) to study potential brain plasticity in this subject. Our results suggest that after 8 years of continuous use of this device there could be significant adaptive and compensatory changes within the brain. In particular, we found changes in functional neural patterns, structural connectivity and cortical topography at the visual and auditive cortex of the Eyeborg user in comparison with a control population. Although at the moment we cannot claim that the continuous use of the Eyeborg is the only reason for these findings, our results may shed further light on potential brain changes associated with the use of other SSDs. This could help to better understand how the brain adapts to several pathologies and uncover adaptive resources such as cross-modal representations. We expect that the precise understanding of these changes will have clear implications for rehabilitative training, device development and for more efficient programs for people with disabilities. PMID:25926778

  8. Hearing colors: an example of brain plasticity.

    PubMed

    Alfaro, Arantxa; Bernabeu, Ángela; Agulló, Carlos; Parra, Jaime; Fernández, Eduardo

    2015-01-01

    Sensory substitution devices (SSDs) are providing new ways for improving or replacing sensory abilities that have been lost due to disease or injury, and at the same time offer unprecedented opportunities to address how the nervous system could lead to an augmentation of its capacities. In this work we have evaluated a color-blind subject using a new visual-to-auditory SSD device called "Eyeborg", that allows colors to be perceived as sounds. We used a combination of neuroimaging techniques including Functional Magnetic Resonance Imaging (fMRI), Diffusion Tensor Imaging (DTI) and proton Magnetic Resonance Spectroscopy ((1)H-MRS) to study potential brain plasticity in this subject. Our results suggest that after 8 years of continuous use of this device there could be significant adaptive and compensatory changes within the brain. In particular, we found changes in functional neural patterns, structural connectivity and cortical topography at the visual and auditive cortex of the Eyeborg user in comparison with a control population. Although at the moment we cannot claim that the continuous use of the Eyeborg is the only reason for these findings, our results may shed further light on potential brain changes associated with the use of other SSDs. This could help to better understand how the brain adapts to several pathologies and uncover adaptive resources such as cross-modal representations. We expect that the precise understanding of these changes will have clear implications for rehabilitative training, device development and for more efficient programs for people with disabilities. PMID:25926778

  9. Models of brain injury and alterations in synaptic plasticity.

    PubMed

    Albensi, B C

    2001-08-15

    Animal models are crucial for understanding human pathophysiological processes and for understanding how connections are injured, lost, or even regenerated and/or repaired. When animal models are used in conjunction with theoretical computational models, an ideal combination is achieved that potentially yields insight and encourages the formation of new theories concerning connectionism, cognitive functioning, and synaptic mechanisms. Mechanisms regulating glutamate receptor activation and intracellular calcium levels are important for normal synaptic transmission. These mechanisms (and others) are also critical during and after brain injury when the potential exists for these mechanisms to function pathologically. Interestingly enough, the regulation of glutamate receptor activation and intracellular calcium levels is also involved in normal processes of neuronal and synaptic plasticity. In addition, studies have shown that neurotrophins and cytokines, which are released after brain injury, can be neuroprotective and may also be important in synaptic plasticity. Furthermore, synaptic plasticity is a phenomenon thought by many to be necessary for memory encoding. If this is the case, then research described in this review has significant scientific merit concerning plasticity and memory and clinical benefit for understanding pathophysiologic processes associated with brain injury and memory impairment. This paper reviews the application of experimental animal models of brain injury for simulating conditions of stroke, trauma, and epilepsy (and/or seizure generation) and the associated cellular mechanisms of brain injury. The paper also briefly addresses the advantage of using computational models in combination with experimental models for hypothesis building and for aiding in the interpretation of empirical data. Finally, it reviews studies concerning brain injury and synaptic plasticity. PMID:11494362

  10. Relating Brain Damage to Brain Plasticity in Patients With Multiple Sclerosis

    PubMed Central

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

    2013-01-01

    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. PMID:22328685

  11. New concepts in surgery of WHO grade II gliomas: functional brain mapping, connectionism and plasticity – a review

    Microsoft Academic Search

    Hugues Duffau

    2006-01-01

    Summary  Despite a recent literature supporting the impact of surgery on the natural history of low-grade glioma (LGG), the indications of resection still remain a matter of debate, especially because of the frequent location of these tumors within eloquent brain areas – thus with a risk to induce a permanent postoperative deficit. Therefore, since the antagonist nature of this surgery is

  12. Regeneration and plasticity in the brain and spinal cord

    Microsoft Academic Search

    Barbro B Johansson

    2007-01-01

    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

  13. Astrocytes and Brain Function: Implications for Reproduction

    Microsoft Academic Search

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

    2003-01-01

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

  14. Experience-dependent structural plasticity in the adult human brain.

    PubMed

    May, Arne

    2011-10-01

    Contrary to assumptions that changes in brain networks are possible only during crucial periods of development, research in the past decade has supported the idea of a permanently plastic brain. Novel experience, altered afferent input due to environmental changes and learning new skills are now recognized as modulators of brain function and underlying neuroanatomic circuitry. Given findings in experiments with animals and the recent discovery of increases in gray and white matter in the adult human brain as a result of learning, the old concept of cognitive reserve, that is the ability to reinforce brain volume in crucial areas and thus provide a greater threshold for age-dependent deficits, has been reinforced. The challenge we face is to unravel the exact nature of the dynamic structural alterations and, ultimately, to be able to use this knowledge for disease management. Understanding normative changes in brain structure that occur as a result of environmental changes and demands is pivotal to understanding the characteristic ability of the brain to adapt. PMID:21906988

  15. Age, Plasticity, and Homeostasis In Childhood Brain Disorders

    PubMed Central

    Dennis, Maureen; Spiegler, Brenda J.; Juranek, Jenifer J.; Bigler, Erin D.; Snead, O. Carter; Fletcher, Jack M.

    2013-01-01

    It has been widely accepted that the younger the age and/or immaturity of the organism, the greater the brain plasticity, the young age plasticity privilege. This paper examines the relation of a young age to plasticity, reviewing human pediatric brain disorders, as well as selected animal models, human developmental and adult brain disorder studies. As well, we review developmental and childhood acquired disorders that involve a failure of regulatory homeostasis. Our core arguments are: Plasticity is neutral with respect to outcome. Although the effects of plasticity are often beneficial, the outcome of plasticity may be adaptive or maladaptive.The young age plasticity privilege has been overstated.Plastic change operates in concert with homeostatic mechanisms regulating change at every point in the lifespan.The same mechanisms that propel developmental change expose the immature brain to adverse events, making it more difficult for the immature than for the mature brain to sustain equilibrium between plasticity and homeostasis.Poor outcome in many neurodevelopmental disorders and childhood acquired brain insults is related to disequilibrium between plasticity and homeostasis. PMID:24096190

  16. Plasticity in the Developing Brain: Implications for Rehabilitation

    ERIC Educational Resources Information Center

    Johnston, Michael V.

    2009-01-01

    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…

  17. Plasticity of Nonneuronal Brain Tissue: Roles in Developmental Disorders

    ERIC Educational Resources Information Center

    Dong, Willie K.; Greenough, William T.

    2004-01-01

    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…

  18. Measuring and Inducing Brain Plasticity in Chronic Aphasia

    ERIC Educational Resources Information Center

    Fridriksson, Julius

    2011-01-01

    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…

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

    PubMed

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

    2011-08-01

    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

  20. Functional genomics of neural and behavioral plasticity.

    PubMed

    Hofmann, Hans A

    2003-01-01

    How does the environment, particularly the social environment, influence brain and behavior and what are the underlying physiologic, molecular, and genetic mechanisms? Adaptations of brain and behavior to changes in the social or physical environment are common in the animal world, either as short-term (i.e., modulatory) or as long-term modifications (e.g., via gene expression changes) in behavioral or physiologic properties. The study of the mechanisms and constraints underlying these dynamic changes requires model systems that offer plastic phenotypes as well as a sufficient level of quantifiable behavioral complexity while being accessible at the physiological and molecular level. In this article, I explore how the new field of functional genomics can contribute to an understanding of the complex relationship between genome and environment that results in highly plastic phenotypes. This approach will lead to the discovery of genes under environmental control and provide the basis for the study of the interrelationship between an individual's gene expression profile and its social phenotype in a given environmental context. PMID:12486709

  1. Structure, function, and plasticity of GABA transporters

    PubMed Central

    Scimemi, Annalisa

    2014-01-01

    GABA transporters belong to a large family of neurotransmitter:sodium symporters. They are widely expressed throughout the brain, with different levels of expression in different brain regions. GABA transporters are present in neurons and in astrocytes and their activity is crucial to regulate the extracellular concentration of GABA under basal conditions and during ongoing synaptic events. Numerous efforts have been devoted to determine the structural and functional properties of GABA transporters. There is also evidence that the expression of GABA transporters on the cell membrane and their lateral mobility can be modulated by different intracellular signaling cascades. The strength of individual synaptic contacts and the activity of entire neuronal networks may be finely tuned by altering the density, distribution and diffusion rate of GABA transporters within the cell membrane. These findings are intriguing because they suggest the existence of complex regulatory systems that control the plasticity of GABAergic transmission in the brain. Here we review the current knowledge on the structural and functional properties of GABA transporters and highlight the molecular mechanisms that alter the expression and mobility of GABA transporters at central synapses. PMID:24987330

  2. PHENOTYPIC PLASTICITY Functional and Conceptual Approaches

    E-print Network

    DeWitt, Thomas J.

    PHENOTYPIC PLASTICITY Functional and Conceptual Approaches Edited by Thomas J. DeWitt Samuel M. A great breadth of ideas fall under the rubric of phenotypic plasticity, and this book is designed these diverse ideas under an intentionally broad definition of plasticity: environment-dependent phenotype

  3. Functional Brain Imaging

    PubMed Central

    2006-01-01

    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

  4. A Plastic Temporal Brain Code for Conscious State Generation

    PubMed Central

    Dresp-Langley, Birgitta; Durup, Jean

    2009-01-01

    Consciousness is known to be limited in processing capacity and often described in terms of a unique processing stream across a single dimension: time. In this paper, we discuss a purely temporal pattern code, functionally decoupled from spatial signals, for conscious state generation in the brain. Arguments in favour of such a code include Dehaene et al.'s long-distance reverberation postulate, Ramachandran's remapping hypothesis, evidence for a temporal coherence index and coincidence detectors, and Grossberg's Adaptive Resonance Theory. A time-bin resonance model is developed, where temporal signatures of conscious states are generated on the basis of signal reverberation across large distances in highly plastic neural circuits. The temporal signatures are delivered by neural activity patterns which, beyond a certain statistical threshold, activate, maintain, and terminate a conscious brain state like a bar code would activate, maintain, or inactivate the electronic locks of a safe. Such temporal resonance would reflect a higher level of neural processing, independent from sensorial or perceptual brain mechanisms. PMID:19644552

  5. Spatiotemporal Computations of an Excitable and Plastic Brain: Neuronal Plasticity Leads to Noise-Robust and Noise-Constructive Computations

    PubMed Central

    Toutounji, Hazem; Pipa, Gordon

    2014-01-01

    It is a long-established fact that neuronal plasticity occupies the central role in generating neural function and computation. Nevertheless, no unifying account exists of how neurons in a recurrent cortical network learn to compute on temporally and spatially extended stimuli. However, these stimuli constitute the norm, rather than the exception, of the brain's input. Here, we introduce a geometric theory of learning spatiotemporal computations through neuronal plasticity. To that end, we rigorously formulate the problem of neural representations as a relation in space between stimulus-induced neural activity and the asymptotic dynamics of excitable cortical networks. Backed up by computer simulations and numerical analysis, we show that two canonical and widely spread forms of neuronal plasticity, that is, spike-timing-dependent synaptic plasticity and intrinsic plasticity, are both necessary for creating neural representations, such that these computations become realizable. Interestingly, the effects of these forms of plasticity on the emerging neural code relate to properties necessary for both combating and utilizing noise. The neural dynamics also exhibits features of the most likely stimulus in the network's spontaneous activity. These properties of the spatiotemporal neural code resulting from plasticity, having their grounding in nature, further consolidate the biological relevance of our findings. PMID:24651447

  6. Removing brakes on adult brain plasticity: from molecular to behavioral interventions

    PubMed Central

    Bavelier, D.; Levi, D.M.; Li, R.W.; Dan, Y.; Hensch, T.K.

    2010-01-01

    Adult brain plasticity, although possible, remains more restricted in scope than during development. Here, we address conditions under which circuit rewiring may be facilitated in the mature brain. At a cellular and molecular level, adult plasticity is actively limited. Some of these “brakes” are structural, such as peri-neuronal nets or myelin, which inhibit neurite outgrowth. Others are functional, acting directly upon excitatory-inhibitory balance within local circuits. Plasticity in adulthood can be induced either by lifting these brakes through invasive interventions or by exploiting endogenous permissive factors, such as neuromodulators. Using the amblyopic visual system as a model, we discuss genetic, pharmacological, and environmental removal of brakes to enable recovery of vision in adult rodents. Although these mechanisms remain largely uncharted in the human, we consider how they may provide a biological foundation for the remarkable increase in plasticity after action video game play by amblyopic subjects. PMID:21068299

  7. Changes in liver mitochondrial plasticity induced by brain tumor

    PubMed Central

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

    2006-01-01

    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. PMID:17018136

  8. Disrupting the brain to guide plasticity and improve behavior.

    PubMed

    Pascual-Leone, Alvaro

    2006-01-01

    Neurones may be highly stable and nonplastic cellular structures, but they are engaged in dynamically changing, intrinsically plastic neural networks that provide a most energy efficient, spatially compact, and precise means to process input signals and generate adaptable responses to a changing environment. Neural plasticity is evolution's invention to enable the nervous system to escape the restrictions of its own genome (and its highly specialized cellular specification) and thus adapt to environmental pressures, physiologic changes, and experiences. At neural system level two steps of plasticity can be identified: unmasking existing connections that may be followed by establishment of new ones possibly even with integration of new neural structures and neurons. In any case, plastic changes may not necessarily represent a behavioral gain for a given subject, as they represent the mechanism for development and learning, as much as a cause of pathology and disease. The challenge is to learn enough about the mechanisms of plasticity to be able to guide them, suppressing changes that may lead to undesirable behaviors while accelerating or enhancing those that result in a behavioral benefit for the subject or patient. Neurostimulation, including noninvasive brain stimulation techniques, provide an opportunity to modulate brain plasticity in a controlled and specific manner. Such interventions to guide behavior or treat pathological symptomatology might be more immediate in their behavioral repercussion and thus more effective than approaches intent on addressing underlying genetic predispositions. PMID:17167918

  9. Regulatory RNAs in Brain Function and Disorders

    PubMed Central

    Iacoangeli, Anna; Bianchi, Riccardo; Tiedge, Henri

    2012-01-01

    Regulatory RNAs are being increasingly investigated in neurons, and important roles in brain function have been revealed. Regulatory RNAs are non-protein-coding RNAs (npcRNAs) that comprise a heterogeneous group of molecules, varying in size and mechanism of action. Regulatory RNAs often exert post-transcriptional control of gene expression, resulting in gene silencing or gene expression stimulation. Here, we review evidence that regulatory RNAs are implicated in neuronal development, differentiation, and plasticity. We will also discuss npcRNA dysregulation that may be involved in pathological states of the brain such as neurodevelopmental disorders, neurodegeneration, and epilepsy. PMID:20307503

  10. Neural Functions of Matrix Metalloproteinases: Plasticity, Neurogenesis, and Disease

    PubMed Central

    Fujioka, Hiromi; Dairyo, Yusuke; Yasunaga, Kei-ichiro; Emoto, Kazuo

    2012-01-01

    The brain changes in response to experience and altered environment. To do that, the nervous system often remodels the structures of neuronal circuits. This structural plasticity of the neuronal circuits appears to be controlled not only by intrinsic factors, but also by extrinsic mechanisms including modification of the extracellular matrix. Recent studies employing a range of animal models implicate that matrix metalloproteinases regulate multiple aspects of the neuronal development and remodeling in the brain. This paper aims to summarize recent advances of our knowledge on the neuronal functions of matrix metalloproteinases and discuss how they might relate in neuronal disease. PMID:22567285

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

    PubMed Central

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

    2009-01-01

    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. PMID:19292910

  12. Functional Lateralization of the Brain.

    ERIC Educational Resources Information Center

    Dean, Raymond S.

    1984-01-01

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

  13. Emerging from an unresponsive wakefulness syndrome: brain plasticity has to cross a threshold level.

    PubMed

    Bagnato, Sergio; Boccagni, Cristina; Sant'angelo, Antonino; Fingelkurts, Alexander A; Fingelkurts, Andrew A; Galardi, Giuseppe

    2013-12-01

    Unresponsive wakefulness syndrome (UWS, previously known as vegetative state) occurs after patients survive a severe brain injury. Patients suffering from UWS have lost awareness of themselves and of the external environment and do not retain any trace of their subjective experience. Current data demonstrate that neuronal functions subtending consciousness are not completely reset in UWS; however, they are reduced below the threshold required to experience consciousness. The critical factor that determines whether patients will recover consciousness is the distance of their neuronal functions from this threshold level. Recovery of consciousness occurs through functional and/or structural changes in the brain, i.e., through neuronal plasticity. Although some of these changes may occur spontaneously, a growing body of evidence indicates that rehabilitative interventions can improve functional outcome by promoting adaptive functional and structural plasticity in the brain, especially if a comprehensive neurophysiological theory of consciousness is followed. In this review we will focus on the pathophysiological mechanisms involved in UWS and on the plastic changes operating on the recovery of consciousness. PMID:24060531

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

    Microsoft Academic Search

    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

    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

  15. Evolution, development, and plasticity of the human brain: from molecules to bones.

    PubMed

    Hrvoj-Mihic, Branka; Bienvenu, Thibault; Stefanacci, Lisa; Muotri, Alysson R; Semendeferi, Katerina

    2013-01-01

    Neuroanatomical, molecular, and paleontological evidence is examined in light of human brain evolution. The brain of extant humans differs from the brains of other primates in its overall size and organization, and differences in size and organization of specific cortical areas and subcortical structures implicated into complex cognition and social and emotional processing. The human brain is also characterized by functional lateralizations, reflecting specializations of the cerebral hemispheres in humans for different types of processing, facilitating fast and reliable communication between neural cells in an enlarged brain. The features observed in the adult brain reflect human-specific patterns of brain development. Compared to the brains of other primates, the human brain takes longer to mature, promoting an extended period for establishing cortical microcircuitry and its modifications. Together, these features may underlie the prolonged period of learning and acquisition of technical and social skills necessary for survival, creating a unique cognitive and behavioral niche typical of our species. The neuroanatomical findings are in concordance with molecular analyses, which suggest a trend toward heterochrony in the expression of genes implicated in different functions. These include synaptogenesis, neuronal maturation, and plasticity in humans, mutations in genes implicated in neurite outgrowth and plasticity, and an increased role of regulatory mechanisms, potentially promoting fast modification of neuronal morphologies in response to new computational demands. At the same time, endocranial casts of fossil hominins provide an insight into the timing of the emergence of uniquely human features in the course of evolution. We conclude by proposing several ways of combining comparative neuroanatomy, molecular biology and insights gained from fossil endocasts in future research. PMID:24194709

  16. Low-frequency transcranial magnetic stimulation is beneficial for enhancing synaptic plasticity in the aging brain

    PubMed Central

    Zhang, Zhan-chi; Luan, Feng; Xie, Chun-yan; Geng, Dan-dan; Wang, Yan-yong; Ma, Jun

    2015-01-01

    In the aging brain, cognitive function gradually declines and causes a progressive reduction in the structural and functional plasticity of the hippocampus. Transcranial magnetic stimulation is an emerging and novel neurological and psychiatric tool used to investigate the neurobiology of cognitive function. Recent studies have demonstrated that low-frequency transcranial magnetic stimulation (?1 Hz) ameliorates synaptic plasticity and spatial cognitive deficits in learning-impaired mice. However, the mechanisms by which this treatment improves these deficits during normal aging are still unknown. Therefore, the current study investigated the effects of transcranial magnetic stimulation on the brain-derived neurotrophic factor signal pathway, synaptic protein markers, and spatial memory behavior in the hippocampus of normal aged mice. The study also investigated the downstream regulator, Fyn kinase, and the downstream effectors, synaptophysin and growth-associated protein 43 (both synaptic markers), to determine the possible mechanisms by which transcranial magnetic stimulation regulates cognitive capacity. Transcranial magnetic stimulation with low intensity (110% average resting motor threshold intensity, 1 Hz) increased mRNA and protein levels of brain-derived neurotrophic factor, tropomyosin receptor kinase B, and Fyn in the hippocampus of aged mice. The treatment also upregulated the mRNA and protein expression of synaptophysin and growth-associated protein 43 in the hippocampus of these mice. In conclusion, brain-derived neurotrophic factor signaling may play an important role in sustaining and regulating structural synaptic plasticity induced by transcranial magnetic stimulation in the hippocampus of aging mice, and Fyn may be critical during this regulation. These responses may change the structural plasticity of the aging hippocampus, thereby improving cognitive function. PMID:26199608

  17. Linking neocortical, cognitive, and genetic variability in autism with alterations of brain plasticity: the Trigger-Threshold-Target model.

    PubMed

    Mottron, Laurent; Belleville, Sylvie; Rouleau, Guy A; Collignon, Olivier

    2014-11-01

    The phenotype of autism involves heterogeneous adaptive traits (strengths vs. disabilities), different domains of alterations (social vs. non-social), and various associated genetic conditions (syndromic vs. nonsyndromic autism). Three observations suggest that alterations in experience-dependent plasticity are an etiological factor in autism: (1) the main cognitive domains enhanced in autism are controlled by the most plastic cortical brain regions, the multimodal association cortices; (2) autism and sensory deprivation share several features of cortical and functional reorganization; and (3) genetic mutations and/or environmental insults involved in autism all appear to affect developmental synaptic plasticity, and mostly lead to its upregulation. We present the Trigger-Threshold-Target (TTT) model of autism to organize these findings. In this model, genetic mutations trigger brain reorganization in individuals with a low plasticity threshold, mostly within regions sensitive to cortical reallocations. These changes account for the cognitive enhancements and reduced social expertise associated with autism. Enhanced but normal plasticity may underlie non-syndromic autism, whereas syndromic autism may occur when a triggering mutation or event produces an altered plastic reaction, also resulting in intellectual disability and dysmorphism in addition to autism. Differences in the target of brain reorganization (perceptual vs. language regions) account for the main autistic subgroups. In light of this model, future research should investigate how individual and sex-related differences in synaptic/regional brain plasticity influence the occurrence of autism. PMID:25155242

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

    Microsoft Academic Search

    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

    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

  19. Mother's voice and heartbeat sounds elicit auditory plasticity in the human brain before full gestation.

    PubMed

    Webb, Alexandra R; Heller, Howard T; Benson, Carol B; Lahav, Amir

    2015-03-10

    Brain development is largely shaped by early sensory experience. However, it is currently unknown whether, how early, and to what extent the newborn's brain is shaped by exposure to maternal sounds when the brain is most sensitive to early life programming. The present study examined this question in 40 infants born extremely prematurely (between 25- and 32-wk gestation) in the first month of life. Newborns were randomized to receive auditory enrichment in the form of audio recordings of maternal sounds (including their mother's voice and heartbeat) or routine exposure to hospital environmental noise. The groups were otherwise medically and demographically comparable. Cranial ultrasonography measurements were obtained at 30 ± 3 d of life. Results show that newborns exposed to maternal sounds had a significantly larger auditory cortex (AC) bilaterally compared with control newborns receiving standard care. The magnitude of the right and left AC thickness was significantly correlated with gestational age but not with the duration of sound exposure. Measurements of head circumference and the widths of the frontal horn (FH) and the corpus callosum (CC) were not significantly different between the two groups. This study provides evidence for experience-dependent plasticity in the primary AC before the brain has reached full-term maturation. Our results demonstrate that despite the immaturity of the auditory pathways, the AC is more adaptive to maternal sounds than environmental noise. Further studies are needed to better understand the neural processes underlying this early brain plasticity and its functional implications for future hearing and language development. PMID:25713382

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

    PubMed Central

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

    2014-01-01

    Patients with brain tumors provide a unique opportunity to understand functional brain plasticity. Using advanced imaging techniques, such as functional MRI and diffusion tensor imaging, we have gained tremendous knowledge of brain tumor behavior, transformation, infiltration and destruction of nearby structures. Using these advanced techniques as an adjunct with more proven techniques, such as direct cortical stimulation, intraoperative navigation and advanced microsurgical techniques, we now are able to better formulate safer resection trajectories, perform larger resections at reduced risk and better counsel patients and their families about possible complications. Brain mapping in patients with brain tumors and other lesions has shown us that the old idea of fixed function of the adult cerebral cortex is not entirely true. Improving care for patients with brain lesions in the future will depend on better understanding of the functional organization and plasticity of the adult brain. Advanced noninvasive brain imaging will undoubtedly play a role in advancing this understanding. PMID:24660024

  1. Functional brain mapping of psychopathology

    PubMed Central

    Honey, G; Fletcher, P; Bullmore, E

    2002-01-01

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

  2. Natriuretic hormones in brain function.

    PubMed

    Hodes, Anastasia; Lichtstein, David

    2014-01-01

    Natriuretic hormones (NH) include three groups of compounds: the natriuretic peptides (ANP, BNP and CNP), the gastrointestinal peptides (guanylin and uroguanylin), and endogenous cardiac steroids. These substances induce the kidney to excrete sodium and therefore participate in the regulation of sodium and water homeostasis, blood volume, and blood pressure (BP). In addition to their peripheral functions, these hormones act as neurotransmitters or neuromodulators in the brain. In this review, the established information on the biosynthesis, release and function of NH is discussed, with particular focus on their role in brain function. The available literature on the expression patterns of each of the NH and their receptors in the brain is summarized, followed by the evidence for their roles in modulating brain function. Although numerous open questions exist regarding this issue, the available data support the notion that NH participate in the central regulation of BP, neuroprotection, satiety, and various psychiatric conditions, including anxiety, addiction, and depressive disorders. In addition, the interactions between the different NH in the periphery and the brain are discussed. PMID:25506340

  3. Natriuretic Hormones in Brain Function

    PubMed Central

    Hodes, Anastasia; Lichtstein, David

    2014-01-01

    Natriuretic hormones (NH) include three groups of compounds: the natriuretic peptides (ANP, BNP and CNP), the gastrointestinal peptides (guanylin and uroguanylin), and endogenous cardiac steroids. These substances induce the kidney to excrete sodium and therefore participate in the regulation of sodium and water homeostasis, blood volume, and blood pressure (BP). In addition to their peripheral functions, these hormones act as neurotransmitters or neuromodulators in the brain. In this review, the established information on the biosynthesis, release and function of NH is discussed, with particular focus on their role in brain function. The available literature on the expression patterns of each of the NH and their receptors in the brain is summarized, followed by the evidence for their roles in modulating brain function. Although numerous open questions exist regarding this issue, the available data support the notion that NH participate in the central regulation of BP, neuroprotection, satiety, and various psychiatric conditions, including anxiety, addiction, and depressive disorders. In addition, the interactions between the different NH in the periphery and the brain are discussed. PMID:25506340

  4. Functional photoacoustic tomography of animal brains 

    E-print Network

    Wang, Xueding

    2005-11-01

    -dimensional tissue structures in intact brains, including lesions and tumors in brain cerebral cortex. Physiological changes and functional activities in brains, including cerebral blood volume and blood oxygenation in addition to anatomical information, were also...

  5. Neural Plasticity in Human Brain Connectivity: The Effects of Long Term Deep Brain Stimulation of the Subthalamic Nucleus in Parkinson’s Disease

    PubMed Central

    van Hartevelt, Tim J.; Cabral, Joana; Deco, Gustavo; Møller, Arne; Green, Alexander L.; Aziz, Tipu Z.; Kringelbach, Morten L.

    2014-01-01

    Background Positive clinical outcomes are now well established for deep brain stimulation, but little is known about the effects of long-term deep brain stimulation on brain structural and functional connectivity. Here, we used the rare opportunity to acquire pre- and postoperative diffusion tensor imaging in a patient undergoing deep brain stimulation in bilateral subthalamic nuclei for Parkinson’s Disease. This allowed us to analyse the differences in structural connectivity before and after deep brain stimulation. Further, a computational model of spontaneous brain activity was used to estimate the changes in functional connectivity arising from the specific changes in structural connectivity. Results We found significant localised structural changes as a result of long-term deep brain stimulation. These changes were found in sensory-motor, prefrontal/limbic, and olfactory brain regions which are known to be affected in Parkinson’s Disease. The nature of these changes was an increase of nodal efficiency in most areas and a decrease of nodal efficiency in the precentral sensory-motor area. Importantly, the computational model clearly shows the impact of deep brain stimulation-induced structural alterations on functional brain changes, which is to shift the neural dynamics back towards a healthy regime. The results demonstrate that deep brain stimulation in Parkinson’s Disease leads to a topological reorganisation towards healthy bifurcation of the functional networks measured in controls, which suggests a potential neural mechanism for the alleviation of symptoms. Conclusions The findings suggest that long-term deep brain stimulation has not only restorative effects on the structural connectivity, but also affects the functional connectivity at a global level. Overall, our results support causal changes in human neural plasticity after long-term deep brain stimulation and may help to identify the underlying mechanisms of deep brain stimulation. PMID:24466120

  6. Functional Brain Basis of Hypnotizability

    PubMed Central

    Hoeft, Fumiko; Gabrieli, John D.E.; Whitfield-Gabrieli, Susan; Haas, Brian W.; Bammer, Roland; Menon, Vinod; Spiegel, David

    2015-01-01

    Context Focused hypnotic concentration is a model for brain control over sensation and behavior. Pain and anxiety can be effectively alleviated by hypnotic suggestion, which modulates activity in brain regions associated with focused attention, but the specific neural network underlying this phenomenon is not known. Objective The main goal of the study was to investigate the brain basis of hypnotizability. Design Cross sectional, in-vivo neuroimaging study. Setting Academic medical center at Stanford University School of Medicine. Patients 12 adults with high and 12 adults with low hypnotizability. Main Outcome Measures (1) functional MRI (fMRI) to measure functional connectivity networks at rest including default-mode, salience and executive-control networks, (2) structural T1 MRI to measure regional grey and white matter volumes, and (3) diffusion tensor imaging (DTI) to measure white matter microstructural integrity. Results High-compared to low-hypnotizable individuals showed greater functional connectivity between left dorsolateral prefrontal cortex (DLPFC), an executive-control region of the brain, and the salience network composed of the dorsal anterior cingulate cortex (dACC), anterior insula, amygdala, and ventral striatum, involved in detecting, integrating, and filtering relevant somatic, autonomic, and emotional information, using independent component analysis (ICA). Seed based analysis confirmed elevated functional coupling between the dACC and the DLPFC in high, compared to low, hypnotizables. These functional differences were not due to variation in brain structure in these regions, including regional grey and white matter volumes and white matter microstructure. Conclusions Our results provide novel evidence that altered functional connectivity in DLPFC and dACC may underlie hypnotizability. Future studies focusing on how these functional networks change and interact during hypnosis are warranted. PMID:23026956

  7. Immune dysregulation and cognitive vulnerability in the aging brain: Interactions of microglia, IL-1?, BDNF and synaptic plasticity.

    PubMed

    Patterson, Susan L

    2015-09-01

    Older individuals often experience declines in cognitive function after events (e.g. infection, or injury) that trigger activation of the immune system. This occurs at least in part because aging sensitizes the response of microglia (the brain's resident immune cells) to signals triggered by an immune challenge. In the aging brain, microglia respond to these signals by producing more pro-inflammatory cytokines (e.g. interleukin-1beta or IL-1?) and producing them for longer than microglia in younger brains. This exaggerated inflammatory response can compromise processes critical for optimal cognitive functioning. Interleukin-1? is central to the inflammatory response and is a key mediator and modulator of an array of associated biological functions; thus its production and release is usually very tightly regulated. This review will focus on the impact of dysregulated production of IL-1? on hippocampus dependent-memory systems and associated synaptic plasticity processes. The neurotrophin brain-derived neurotrophic factor (BNDF) helps to protect neurons from damage caused by infection or injury, and it plays a critical role in many of the same memory and hippocampal plasticity processes compromised by dysregulated production of IL-1?. This suggests that an exaggerated brain inflammatory response, arising from aging and a secondary immune challenge, may erode the capacity to provide the BDNF needed for memory-related plasticity processes at hippocampal synapses. This article is part of a Special Issue entitled 'Neuroimmunology and Synaptic Function'. PMID:25549562

  8. Exercise: a behavioral intervention to enhance brain health and plasticity

    Microsoft Academic Search

    Carl W. Cotman; Nicole C. Berchtold

    2002-01-01

    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

  9. Sleep, plasticity and memory from molecules to whole-brain networks.

    PubMed

    Abel, Ted; Havekes, Robbert; Saletin, Jared M; Walker, Matthew P

    2013-09-01

    Despite the ubiquity of sleep across phylogeny, its function remains elusive. In this review, we consider one compelling candidate: brain plasticity associated with memory processing. Focusing largely on hippocampus-dependent memory in rodents and humans, we describe molecular, cellular, network, whole-brain and behavioral evidence establishing a role for sleep both in preparation for initial memory encoding, and in the subsequent offline consolidation of memory. Sleep and sleep deprivation bidirectionally alter molecular signaling pathways that regulate synaptic strength and control plasticity-related gene transcription and protein translation. At the cellular level, sleep deprivation impairs cellular excitability necessary for inducing synaptic potentiation and accelerates the decay of long-lasting forms of synaptic plasticity. In contrast, rapid eye movement (REM) and non-rapid eye movement (NREM) sleep enhance previously induced synaptic potentiation, although synaptic de-potentiation during sleep has also been observed. Beyond single cell dynamics, large-scale cell ensembles express coordinated replay of prior learning-related firing patterns during subsequent NREM sleep. At the whole-brain level, somewhat analogous learning-associated hippocampal (re)activation during NREM sleep has been reported in humans. Moreover, the same cortical NREM oscillations associated with replay in rodents also promote human hippocampal memory consolidation, and this process can be manipulated using exogenous reactivation cues during sleep. Mirroring molecular findings in rodents, specific NREM sleep oscillations before encoding refresh human hippocampal learning capacity, while deprivation of sleep conversely impairs subsequent hippocampal activity and associated encoding. Together, these cross-descriptive level findings demonstrate that the unique neurobiology of sleep exerts powerful effects on molecular, cellular and network mechanisms of plasticity that govern both initial learning and subsequent long-term memory consolidation. PMID:24028961

  10. Physical exercise in overweight to obese individuals induces metabolic- and neurotrophic-related structural brain plasticity

    PubMed Central

    Mueller, Karsten; Möller, Harald E.; Horstmann, Annette; Busse, Franziska; Lepsien, Jöran; Blüher, Matthias; Stumvoll, Michael; Villringer, Arno; Pleger, Burkhard

    2015-01-01

    Previous cross-sectional studies on body-weight-related alterations in brain structure revealed profound changes in the gray matter (GM) and white matter (WM) that resemble findings obtained from individuals with advancing age. This suggests that obesity may lead to structural brain changes that are comparable with brain aging. Here, we asked whether weight-loss-dependent improved metabolic and neurotrophic functioning parallels the reversal of obesity-related alterations in brain structure. To this end we applied magnetic resonance imaging (MRI) together with voxel-based morphometry and diffusion-tensor imaging in overweight to obese individuals who participated in a fitness course with intensive physical training twice a week over a period of 3 months. After the fitness course, participants presented, with inter-individual heterogeneity, a reduced body mass index (BMI), reduced serum leptin concentrations, elevated high-density lipoprotein-cholesterol (HDL-C), and alterations of serum brain-derived neurotrophic factor (BDNF) concentrations suggesting changes of metabolic and neurotrophic function. Exercise-dependent changes in BMI and serum concentration of BDNF, leptin, and HDL-C were related to an increase in GM density in the left hippocampus, the insular cortex, and the left cerebellar lobule. We also observed exercise-dependent changes of diffusivity parameters in surrounding WM structures as well as in the corpus callosum. These findings suggest that weight-loss due to physical exercise in overweight to obese participants induces profound structural brain plasticity, not primarily of sensorimotor brain regions involved in physical exercise, but of regions previously reported to be structurally affected by an increased body weight and functionally implemented in gustation and cognitive processing.

  11. Organization and Functions of the Brain

    Microsoft Academic Search

    Lubica Benuskova; Nikola Kasabov

    \\u000a This chapter gives an overview of the brain organization and functions performed by different parts of the brain. We will\\u000a try to answer the following questions: How is the human brain organized at the macroscopic and microscopic levels? Which functions\\u000a are performed by the brain? How is the organization of the human brain related to its functions? These and many

  12. Brain structural and functional development: genetics and experience.

    PubMed

    Berardi, Nicoletta; Sale, Alessandro; Maffei, Lamberto

    2015-04-01

    Brain development is the result of the combined work of genes and environment. In this paper we first briefly discuss how, in terms of cellular and molecular plasticity mechanisms, the richness of early environment can control developmental trajectories and can induce long-term changes in neural circuits that underlie enduring changes in brain structure and function. We then see that experience most effectively moulds neural circuit development during specific time windows called critical periods. After the closure of these privileged windows for plasticity, it is very difficult to promote repair from 'errors' in brain development. As an example, congenital cataracts, refractive defects, or strabismus, if not precociously corrected during development, cause permanent deficit in visual acuity of the affected eye, a condition known as amblyopia. Little or no recovery from amblyopia is possible in the adult. However, recent results show that by using protocols of enriched environment it is possible to design interventions, which, by acting on specific plasticity factors, enhance adult cortical plasticity and allow recovery from amblyopia. This suggests that a better knowledge of how experience and environment engage endogenous plasticity factors could help to design interventions aimed at promoting recovery from neurodevelopmental defects, even after the end of critical periods. PMID:25690109

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

    PubMed Central

    Mandonnet, Emmanuel; Duffau, Hugues

    2014-01-01

    Historically, cerebral processing has been conceptualized as a framework based on statically localized functions. However, a growing amount of evidence supports a hodotopical (delocalized) and flexible organization. A number of studies have reported absence of a permanent neurological deficit after massive surgical resections of eloquent brain tissue. These results highlight the tremendous plastic potential of the brain. Understanding anatomo-functional correlates underlying this cerebral reorganization is a prerequisite to restore brain functions through brain-computer interfaces (BCIs) in patients with cerebral diseases, or even to potentiate brain functions in healthy individuals. Here, we review current knowledge of neural networks that could be utilized in the BCIs that enable movements and language. To this end, intraoperative electrical stimulation in awake patients provides valuable information on the cerebral functional maps, their connectomics and plasticity. Overall, these studies indicate that the complex cerebral circuitry that underpins interactions between action, cognition and behavior should be throughly investigated before progress in BCI approaches can be achieved. PMID:24834030

  14. Day differences in the cortisol awakening response predict day differences in synaptic plasticity in the brain.

    PubMed

    Clow, Angela; Law, Robin; Evans, Phil; Vallence, Ann-Maree; Hodyl, Nicolette A; Goldsworthy, Mitchell R; Rothwell, John R; Ridding, Michael C

    2014-05-01

    The cortisol awakening response (CAR) is the most prominent, dynamic and variable part of the circadian pattern of cortisol secretion. Despite this, its precise purpose is unknown. Aberrant patterns of the CAR are associated with impaired physical and mental health and reduced cognitive function, suggesting that it may have a pervasive role or roles. It has been suggested that the CAR primes the brain for the expected demands of the day but the mechanisms underlying this process are unknown. We examined temporal covariation of the CAR and rapid transcranial magnetic stimulation (rTMS)-induced long term depression (LTD)-like responses in the motor cortex. Plasticity was evaluated across 180 measures from five time points on four sessions across nine healthy researcher participants, mean age 25?±?2.5 years. Plasticity estimates were obtained in the afternoon after measurement of the CAR on 4 days, at least 3 days apart. As both CAR magnitude and rTMS-induced responses are variable across days, we hypothesized that days with larger than individual average CARs would be associated with a greater than individual average plasticity response. This was confirmed by mixed regression modelling where variation in the CAR predicted variation in rTMS-induced responses (df: 1, 148.24; F: 10.41; p?=?0.002). As the magnitude of the CAR is regulated by the "master" circadian CLOCK, and synaptic plasticity is known to be modulated by peripheral "slave" CLOCK genes, we suggest that the CAR may be a mediator between the master and peripheral circadian systems to entrain daily levels of synaptic plasticity. PMID:24646342

  15. SIRT1 is essential for normal cognitive function and synaptic plasticity

    PubMed Central

    Michán, 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

    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. PMID:20660252

  16. Simultaneous Brain–Cervical Cord fMRI Reveals Intrinsic Spinal Cord Plasticity during Motor Sequence Learning

    PubMed Central

    Cohen-Adad, Julien; Marchand-Pauvert, Veronique; Benali, Habib; Doyon, Julien

    2015-01-01

    The spinal cord participates in the execution of skilled movements by translating high-level cerebral motor representations into musculotopic commands. Yet, the extent to which motor skill acquisition relies on intrinsic spinal cord processes remains unknown. To date, attempts to address this question were limited by difficulties in separating spinal local effects from supraspinal influences through traditional electrophysiological and neuroimaging methods. Here, for the first time, we provide evidence for local learning-induced plasticity in intact human spinal cord through simultaneous functional magnetic resonance imaging of the brain and spinal cord during motor sequence learning. Specifically, we show learning-related modulation of activity in the C6–C8 spinal region, which is independent from that of related supraspinal sensorimotor structures. Moreover, a brain–spinal cord functional connectivity analysis demonstrates that the initial linear relationship between the spinal cord and sensorimotor cortex gradually fades away over the course of motor sequence learning, while the connectivity between spinal activity and cerebellum gains strength. These data suggest that the spinal cord not only constitutes an active functional component of the human motor learning network but also contributes distinctively from the brain to the learning process. The present findings open new avenues for rehabilitation of patients with spinal cord injuries, as they demonstrate that this part of the central nervous system is much more plastic than assumed before. Yet, the neurophysiological mechanisms underlying this intrinsic functional plasticity in the spinal cord warrant further investigations. PMID:26125597

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

    PubMed

    Coffey, Emily B J; Herholz, Sibylle C

    2013-01-01

    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

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

    Microsoft Academic Search

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

    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

  19. Anatomical Correlates of Functional Plasticity in Mouse Visual Cortex

    Microsoft Academic Search

    Antonella Antonini; Michela Fagiolini; Michael P. Stryker

    1999-01-01

    Much of what is known about activity-dependent plasticity comes from studies of the primary visual cortex and its inputs in higher mammals, but the molecular bases remain largely unknown. Similar functional plasticity takes place during a crit- ical period in the visual cortex of the mouse, an animal in which genetic experiments can readily be performed to investigate the underlying

  20. Brain Surface Conformal Parameterization with Algebraic Functions

    E-print Network

    Wang, Yalin

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

  1. Brain dynamics promotes function Carlos Lourenco

    E-print Network

    Lisboa, Universidade Técnica de

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

  2. Brain Surface Conformal Parameterization with Algebraic Functions

    E-print Network

    Wang, Yalin

    Brain Surface Conformal Parameterization with Algebraic Functions 1,2Yalin Wang , 3Xianfeng Gu, 1 Angeles, CA, USA. 2Laboratory of Neuro Imaging, Brain Mapping Division, Department of Neurology, UCLA previous work conformally parameterizes various brain anatomical surfaces with several planar

  3. How a child builds its brain: some lessons from animal studies of neural plasticity.

    PubMed

    Black, J E

    1998-01-01

    Although the potential vulnerability of children's brain development is generally recognized, relatively little is known about the timing, resiliency, or mechanisms involved. While animal research should be applied only cautiously to human policy, some findings do have important clinical implications. This paper briefly reviews animal studies demonstrating the effects of experience on brain structure. Contemporary theories emphasize the self-organizing potential of brain structure, particularly regions that seem to have evolved for the purpose of storing information. We emphasize three major findings: (1) many regions of the brain are responsive to experience, but they differ in the types of information stored and in their developmental timing. (2) One type of plasticity is typically embedded in a developmental program, and it requires appropriate timing and quality of the information stored for the animal's development to be normal. (3) Another category of plasticity stores information that is idiosyncratic and unpredictable, but is often useful for species such as humans that learn throughout their life span. We therefore expect that some aspects of human brain development use the first type of plasticity and that abnormal experience or deprivation may cause lasting harm to brain and behavior. However, because the other type of plasticity lasts a lifetime, efforts such as psychotherapy or social interventions may help heal a wounded brain. PMID:9578989

  4. The brain timewise: how timing shapes and supports brain function

    PubMed Central

    Hari, Riitta; Parkkonen, Lauri

    2015-01-01

    We discuss the importance of timing in brain function: how temporal dynamics of the world has left its traces in the brain during evolution and how we can monitor the dynamics of the human brain with non-invasive measurements. Accurate timing is important for the interplay of neurons, neuronal circuitries, brain areas and human individuals. In the human brain, multiple temporal integration windows are hierarchically organized, with temporal scales ranging from microseconds to tens and hundreds of milliseconds for perceptual, motor and cognitive functions, and up to minutes, hours and even months for hormonal and mood changes. Accurate timing is impaired in several brain diseases. From the current repertoire of non-invasive brain imaging methods, only magnetoencephalography (MEG) and scalp electroencephalography (EEG) provide millisecond time-resolution; our focus in this paper is on MEG. Since the introduction of high-density whole-scalp MEG/EEG coverage in the 1990s, the instrumentation has not changed drastically; yet, novel data analyses are advancing the field rapidly by shifting the focus from the mere pinpointing of activity hotspots to seeking stimulus- or task-specific information and to characterizing functional networks. During the next decades, we can expect increased spatial resolution and accuracy of the time-resolved brain imaging and better understanding of brain function, especially its temporal constraints, with the development of novel instrumentation and finer-grained, physiologically inspired generative models of local and network activity. Merging both spatial and temporal information with increasing accuracy and carrying out recordings in naturalistic conditions, including social interaction, will bring much new information about human brain function. PMID:25823867

  5. Music mnemonics aid Verbal Memory and Induce Learning - Related Brain Plasticity in Multiple Sclerosis.

    PubMed

    Thaut, Michael H; Peterson, David A; McIntosh, Gerald C; Hoemberg, Volker

    2014-01-01

    Recent research on music and brain function has suggested that the temporal pattern structure in music and rhythm can enhance cognitive functions. To further elucidate this question specifically for memory, we investigated if a musical template can enhance verbal learning in patients with multiple sclerosis (MS) and if music-assisted learning will also influence short-term, system-level brain plasticity. We measured systems-level brain activity with oscillatory network synchronization during music-assisted learning. Specifically, we measured the spectral power of 128-channel electroencephalogram (EEG) in alpha and beta frequency bands in 54 patients with MS. The study sample was randomly divided into two groups, either hearing a spoken or a musical (sung) presentation of Rey's auditory verbal learning test. We defined the "learning-related synchronization" (LRS) as the percent change in EEG spectral power from the first time the word was presented to the average of the subsequent word encoding trials. LRS differed significantly between the music and the spoken conditions in low alpha and upper beta bands. Patients in the music condition showed overall better word memory and better word order memory and stronger bilateral frontal alpha LRS than patients in the spoken condition. The evidence suggests that a musical mnemonic recruits stronger oscillatory network synchronization in prefrontal areas in MS patients during word learning. It is suggested that the temporal structure implicit in musical stimuli enhances "deep encoding" during verbal learning and sharpens the timing of neural dynamics in brain networks degraded by demyelination in MS. PMID:24982626

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

    PubMed Central

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

    2012-01-01

    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. PMID:23217714

  7. Functional genomics of neural and behavioral plasticity

    Microsoft Academic Search

    Hans A. Hofmann

    2003-01-01

    How does the environment, particu- larly the social environment, influence brain and behav- ior and what are the underlying physiologic, molecular, and genetic mechanisms? Adaptations of brain and be- havior to changes in the social or physical environment are common in the animal world, either as short-term (i.e., modulatory) or as long-term modifications (e.g., via gene expression changes) in behavioral

  8. Complement emerges as a masterful regulator of CNS homeostasis, neural synaptic plasticity and cognitive function.

    PubMed

    Mastellos, Dimitrios C

    2014-11-01

    Growing evidence points to a previously elusive role of complement-modulated pathways in CNS development, neurogenesis and synaptic plasticity. Distinct complement effectors appear to play a multifaceted role in brain homeostasis by regulating synaptic pruning in the retinogeniculate system and sculpting functional neural circuits both in the developing and adult mammalian brain. A recent study by Perez-Alcazar et al. (2014) provides novel insights into this intricate interplay between complement and the dynamically regulated brain synaptic circuitry, by reporting that mice deficient in C3 exhibit enhanced hippocampus-dependent spatial learning and cognitive performance. This behavioral pattern is associated with an impact of C3 on the functional capacity of glutamatergic synapses, supporting a crucial role for complement in excitatory synapse elimination in the hippocampus. These findings add a fresh twist to this rapidly evolving research field, suggesting that discrete complement components may differentially modulate synaptic connectivity by wiring up with diverse neural effectors in different regions of the brain. The emerging role of complement in synaptogenesis and neural network plasticity opens new conceptual avenues for considering complement interception as a potential therapeutic modality for ameliorating progressive cognitive impairment in age-related, debilitating brain diseases with a prominent inflammatory signature. PMID:24975369

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

    Microsoft Academic Search

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

    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

  10. The restless brain: how intrinsic activity organizes brain function

    PubMed Central

    Raichle, Marcus E.

    2015-01-01

    Traditionally studies of brain function have focused on task-evoked responses. By their very nature such experiments tacitly encourage a reflexive view of brain function. While such an approach has been remarkably productive at all levels of neuroscience, it ignores the alternative possibility that brain functions are mainly intrinsic and ongoing, involving information processing for interpreting, responding to and predicting environmental demands. I suggest that the latter view best captures the essence of brain function, a position that accords well with the allocation of the brain's energy resources, its limited access to sensory information and a dynamic, intrinsic functional organization. The nature of this intrinsic activity, which exhibits a surprising level of organization with dimensions of both space and time, is revealed in the ongoing activity of the brain and its metabolism. As we look to the future, understanding the nature of this intrinsic activity will require integrating knowledge from cognitive and systems neuroscience with cellular and molecular neuroscience where ion channels, receptors, components of signal transduction and metabolic pathways are all in a constant state of flux. The reward for doing so will be a much better understanding of human behaviour in health and disease. PMID:25823869

  11. Bioengineered functional brain-like cortical tissue

    PubMed Central

    Tang-Schomer, Min D.; White, James D.; Tien, Lee W.; Schmitt, L. Ian; Valentin, Thomas M.; Graziano, Daniel J.; Hopkins, Amy M.; Omenetto, Fiorenzo G.; Haydon, Philip G.; Kaplan, David L.

    2014-01-01

    The brain remains one of the most important but least understood tissues in our body, in part because of its complexity as well as the limitations associated with in vivo studies. Although simpler tissues have yielded to the emerging tools for in vitro 3D tissue cultures, functional brain-like tissues have not. We report the construction of complex functional 3D brain-like cortical tissue, maintained for months in vitro, formed from primary cortical neurons in modular 3D compartmentalized architectures with electrophysiological function. We show that, on injury, this brain-like tissue responds in vitro with biochemical and electrophysiological outcomes that mimic observations in vivo. This modular 3D brain-like tissue is capable of real-time nondestructive assessments, offering previously unidentified directions for studies of brain homeostasis and injury. PMID:25114234

  12. Modulation of Rho GTPases rescues brain mitochondrial dysfunction, cognitive deficits and aberrant synaptic plasticity in female mice modeling Rett syndrome.

    PubMed

    De Filippis, Bianca; Valenti, Daniela; Chiodi, Valentina; Ferrante, Antonella; de Bari, Lidia; Fiorentini, Carla; Domenici, Maria Rosaria; Ricceri, Laura; Vacca, Rosa Anna; Fabbri, Alessia; Laviola, Giovanni

    2015-06-01

    Rho GTPases are molecules critically involved in neuronal plasticity and cognition. We have previously reported that modulation of brain Rho GTPases by the bacterial toxin CNF1 rescues the neurobehavioral phenotype in MeCP2-308 male mice, a model of Rett syndrome (RTT). RTT is a rare X-linked neurodevelopmental disorder and a genetic cause of intellectual disability, for which no effective therapy is available. Mitochondrial dysfunction has been proposed to be involved in the mechanism of the disease pathogenesis. Here we demonstrate that modulation of Rho GTPases by CNF1 rescues the reduced mitochondrial ATP production via oxidative phosphorylation in the brain of MeCP2-308 heterozygous female mice, the condition which more closely recapitulates that of RTT patients. In RTT mouse brain, CNF1 also restores the alterations in the activity of the mitochondrial respiratory chain (MRC) complexes and of ATP synthase, the molecular machinery responsible for the majority of cell energy production. Such effects were achieved through the upregulation of the protein content of those MRC complexes subunits, which were defective in RTT mouse brain. Restored mitochondrial functionality was accompanied by the rescue of deficits in cognitive function (spatial reference memory in the Barnes maze), synaptic plasticity (long-term potentiation) and Tyr1472 phosphorylation of GluN2B, which was abnormally enhanced in the hippocampus of RTT mice. Present findings bring into light previously unknown functional mitochondrial alterations in the brain of female mice modeling RTT and provide the first evidence that RTT brain mitochondrial dysfunction can be rescued by modulation of Rho GTPases. PMID:25890884

  13. Domestication and Plasticity of Brain Organization in Mallards (Anas platyrhynchos)

    Microsoft Academic Search

    Peter Ebinger

    1995-01-01

    The sizes and histological differentiation of structures in the central nervous system of wild and domestic ducks were compared using allometric methods. Whole brain volume is 14.3% less in domestic ducks than in wild birds, and the size of certain brain structures is more variable in domestic ducks than in the wild birds. These findings are consistent with results of

  14. Energetic cost of brain functional connectivity

    PubMed Central

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

    2013-01-01

    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

  15. [Regulation of brain microvessel function].

    PubMed

    Kobayashi, Hideyuki; Yokoo, Hiroki; Yanagita, Toshihiko; Wada, Akihiko

    2002-05-01

    The brain microvessels are formed by a specialized endothelium and regulate the movement of solutes between blood and brain. The endothelial cells are sealed together by tight junctions and play a role as the blood-brain barrier. The brain microvessels express GLUT1 as the major form of glucose transporter, aquaporin-4 as a water channel, and p-glycoprotein as a xenobiotic transporter. Occludin and claudin-5 have been identified as the components of tight junction. Increasing evidence suggests that the activities of the transporters are regulated by adrenergic nerve activity as well as by bioactive peptides such as adrenomedullin. The regulation of the activity as well as expression of these transporters may become a strategy for prophylaxis and treatment of not only cerebral vascular diseases but also neurodegenerative disorders, developmental abnormalities and aging of the brain. PMID:12061139

  16. Relationship of calpain-mediated proteolysis to the expression of axonal and synaptic plasticity markers following traumatic brain injury in mice

    Microsoft Academic Search

    Stephanie N. Thompson; Tonya R. Gibson; Brian M. Thompson; Ying Deng; Edward D. Hall

    2006-01-01

    The role of neuronal plasticity and repair on the final functional outcome following traumatic brain injury (TBI) remains poorly understood. Moreover, the relationship of the magnitude of post-traumatic secondary injury and neurodegeneration to the potential for neuronal repair has not been explored. To address these questions, we employed Western immunoblotting techniques to examine how injury severity affects the spatial and

  17. Functional Aspects of Creatine Kinase in Brain

    Microsoft Academic Search

    Wolfram Hemmer; Theo Wallimann

    1993-01-01

    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

  18. Brain lateralization and neural plasticity for musical and cognitive abilities in an epileptic musician.

    PubMed

    Trujillo-Pozo, Isabel; Martín-Monzón, Isabel; Rodríguez-Romero, Rafael

    2013-01-01

    The use of intracarotid propofol procedure (IPP) when assessing musical lateralization has not been reported in literature up to now. This procedure (similar to Wada Test) has provided the opportunity to investigate not only lateralization of language and memory functions on epileptic patients but also offers a functional mapping approach with superior spatial and temporal resolution to analyze the lateralization of musical abilities. Findings in literature suggest that musical training modifies functional and structural brain organization. We studied hemispheric lateralization in a professional musician, a 33 years old woman with refractory left medial temporal lobe (MTL) epilepsy (TLE). A longitudinal neuropsychological study was performed over a period of 21 months. Before epilepsy surgery, musical abilities, language and memory were tested during IPP by means of a novel and exhaustive neuropsychological battery focusing on the processing of music. We used a selection of stimuli to analyze listening, score reading, and tempo discrimination. Our results suggested that IPP is an excellent method to determine not only language, semantic, and episodic memory, but also musical dominance in a professional musician who may be candidate for epilepsy surgery. Neuropsychological testing revealed that right hemisphere's patient is involved in semantic and episodic musical memory processes, whereas her score reading and tempo processing require contribution from both hemispheres. At one-year follow-up, outcome was excellent with respect to seizures and professional skills, meanwhile cognitive abilities improved. These findings indicate that IPP helps to predict who might be at risk for postoperative musical, language, and memory deficits after epilepsy surgery. Our research suggests that musical expertise and epilepsy critically modifies long-term memory processes and induces brain structural and functional plasticity. PMID:24367312

  19. Functional connectivity hubs of the mouse brain.

    PubMed

    Liska, Adam; Galbusera, Alberto; Schwarz, Adam J; Gozzi, Alessandro

    2015-07-15

    Recent advances in functional connectivity methods have made it possible to identify brain hubs - a set of highly connected regions serving as integrators of distributed neuronal activity. The integrative role of hub nodes makes these areas points of high vulnerability to dysfunction in brain disorders, and abnormal hub connectivity profiles have been described for several neuropsychiatric disorders. The identification of analogous functional connectivity hubs in preclinical species like the mouse may provide critical insight into the elusive biological underpinnings of these connectional alterations. To spatially locate functional connectivity hubs in the mouse brain, here we applied a fully-weighted network analysis to map whole-brain intrinsic functional connectivity (i.e., the functional connectome) at a high-resolution voxel-scale. Analysis of a large resting-state functional magnetic resonance imaging (rsfMRI) dataset revealed the presence of six distinct functional modules related to known large-scale functional partitions of the brain, including a default-mode network (DMN). Consistent with human studies, highly-connected functional hubs were identified in several sub-regions of the DMN, including the anterior and posterior cingulate and prefrontal cortices, in the thalamus, and in small foci within well-known integrative cortical structures such as the insular and temporal association cortices. According to their integrative role, the identified hubs exhibited mutual preferential interconnections. These findings highlight the presence of evolutionarily-conserved, mutually-interconnected functional hubs in the mouse brain, and may guide future investigations of the biological foundations of aberrant rsfMRI hub connectivity associated with brain pathological states. PMID:25913701

  20. Active zones for presynaptic plasticity in the brain

    Microsoft Academic Search

    P García-Junco-Clemente; P Linares-Clemente; R Fernández-Chacón

    2005-01-01

    Some of the most abundant synapses in the brain such as the synapses formed by the hippocampal mossy fibers, cerebellar parallel fibers and several types of cortical afferents express presynaptic forms of long-term potentiation (LTP), a putative cellular model for spatial, motor and fear learning. Those synapses often display presynaptic mechanisms of LTP induction, which are either NMDA receptor independent

  1. Altered brain functional networks in heavy smokers.

    PubMed

    Lin, Fuchun; Wu, Guangyao; Zhu, Ling; Lei, Hao

    2015-07-01

    Recent neuroimaging studies have demonstrated that cigarette smoking is associated with changed brain structure and function. However, little is known about alterations of the topological organization of brain functional networks in heavy smokers. Thirty-one heavy smokers and 33 non-smokers underwent a resting-state functional magnetic resonance imaging scan. The whole-brain functional networks were constructed by thresholding the correlation matrices of 90 brain regions and their topological properties were analyzed using graph network analysis. Non-parametric permutation tests were performed to investigate group differences in network topological measures and multiple regression analysis was conducted to determine the relationships between the network metrics and smoking-related variables. Both heavy smokers and non-smokers exhibited small-world architecture in their brain functional networks. Compared with non-smokers, however, heavy smokers showed altered topological measurements characterized by lower global efficiency, higher local efficiency and clustering coefficients and greater path length. Furthermore, heavy smokers demonstrated decreased nodal global efficiency mainly in brain regions within the default mode network, whereas increased nodal local efficiency predominated in the visual-related regions. In addition, heavy smokers exhibited an association between the altered network metrics and the duration of cigarette use or the severity of nicotine dependence. Our results suggest that heavy smokers may have less efficient network architecture in the brain, and chronic cigarette smoking is associated with disruptions in the topological organization of brain networks. Our findings may further the understanding of the effects of chronic cigarette smoking on the brain and the pathophysiological mechanisms underlying nicotine dependence. PMID:24962385

  2. Genetic Rescue of Functional Senescence in Synaptic and Behavioral Plasticity

    PubMed Central

    Donlea, Jeffrey M.; Ramanan, Narendrakumar; Silverman, Neal; Shaw, Paul J.

    2014-01-01

    Study Objectives: Aging has been linked with decreased neural plasticity and memory formation in humans and in laboratory model species such as the fruit fly, Drosophila melanogaster. Here, we examine plastic responses following social experience in Drosophila as a high-throughput method to identify interventions that prevent these impairments. Patients or Participants: Wild-type and transgenic Drosophila melanogaster. Design and Interventions: Young (5-day old) or aged (20-day old) adult female Drosophila were housed in socially enriched (n = 35-40) or isolated environments, then assayed for changes in sleep and for structural markers of synaptic terminal growth in the ventral lateral neurons (LNVs) of the circadian clock. Measurements and Results: When young flies are housed in a socially enriched environment, they exhibit synaptic elaboration within a component of the circadian circuitry, the LNVs, which is followed by increased sleep. Aged flies, however, no longer exhibit either of these plastic changes. Because of the tight correlation between neural plasticity and ensuing increases in sleep, we use sleep after enrichment as a high-throughput marker for neural plasticity to identify interventions that prolong youthful plasticity in aged flies. To validate this strategy, we find three independent genetic manipulations that delay age-related losses in plasticity: (1) elevation of dopaminergic signaling, (2) over-expression of the transcription factor blistered (bs) in the LNVs, and (3) reduction of the Imd immune signaling pathway. These findings provide proof-of-principle evidence that measuring changes in sleep in flies after social enrichment may provide a highly scalable assay for the study of age-related deficits in synaptic plasticity. Conclusions: These studies demonstrate that Drosophila provides a promising model for the study of age-related loss of neural plasticity and begin to identify genes that might be manipulated to delay the onset of functional senescence. Citation: Donlea JM, Ramanan N, Silverman N, Shaw PJ. Genetic rescue of functional senescence in synaptic and behavioral plasticity. SLEEP 2014;37(9):1427-1437. PMID:25142573

  3. Functional brain development in humans

    Microsoft Academic Search

    Mark H. Johnson

    2001-01-01

    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

  4. Relationship between structural brainstem and brain plasticity and lower-limb training in spinal cord injury: a longitudinal pilot study.

    PubMed

    Villiger, Michael; Grabher, Patrick; Hepp-Reymond, Marie-Claude; Kiper, Daniel; Curt, Armin; Bolliger, Marc; Hotz-Boendermaker, Sabina; Kollias, Spyros; Eng, Kynan; Freund, Patrick

    2015-01-01

    Rehabilitative training has shown to improve significantly motor outcomes and functional walking capacity in patients with incomplete spinal cord injury (iSCI). However, whether performance improvements during rehabilitation relate to brain plasticity or whether it is based on functional adaptation of movement strategies remain uncertain. This study assessed training improvement-induced structural brain plasticity in chronic iSCI patients using longitudinal MRI. We used tensor-based morphometry (TBM) to analyze longitudinal brain volume changes associated with intensive virtual reality (VR)-augmented lower limb training in nine traumatic iSCI patients. The MRI data was acquired before and after a 4-week training period (16-20 training sessions). Before training, voxel-based morphometry (VBM) and voxel-based cortical thickness (VBCT) assessed baseline morphometric differences in nine iSCI patients compared to 14 healthy controls. The intense VR-augmented training of limb control improved significantly balance, walking speed, ambulation, and muscle strength in patients. Retention of clinical improvements was confirmed by the 3-4 months follow-up. In patients relative to controls, VBM revealed reductions of white matter volume within the brainstem and cerebellum and VBCT showed cortical thinning in the primary motor cortex. Over time, TBM revealed significant improvement-induced volume increases in the left middle temporal and occipital gyrus, left temporal pole and fusiform gyrus, both hippocampi, cerebellum, corpus callosum, and brainstem in iSCI patients. This study demonstrates structural plasticity at the cortical and brainstem level as a consequence of VR-augmented training in iSCI patients. These structural changes may serve as neuroimaging biomarkers of VR-augmented lower limb neurorehabilitation in addition to performance measures to detect improvements in rehabilitative training. PMID:25999842

  5. Relationship between structural brainstem and brain plasticity and lower-limb training in spinal cord injury: a longitudinal pilot study

    PubMed Central

    Villiger, Michael; Grabher, Patrick; Hepp-Reymond, Marie-Claude; Kiper, Daniel; Curt, Armin; Bolliger, Marc; Hotz-Boendermaker, Sabina; Kollias, Spyros; Eng, Kynan; Freund, Patrick

    2015-01-01

    Rehabilitative training has shown to improve significantly motor outcomes and functional walking capacity in patients with incomplete spinal cord injury (iSCI). However, whether performance improvements during rehabilitation relate to brain plasticity or whether it is based on functional adaptation of movement strategies remain uncertain. This study assessed training improvement-induced structural brain plasticity in chronic iSCI patients using longitudinal MRI. We used tensor-based morphometry (TBM) to analyze longitudinal brain volume changes associated with intensive virtual reality (VR)-augmented lower limb training in nine traumatic iSCI patients. The MRI data was acquired before and after a 4-week training period (16–20 training sessions). Before training, voxel-based morphometry (VBM) and voxel-based cortical thickness (VBCT) assessed baseline morphometric differences in nine iSCI patients compared to 14 healthy controls. The intense VR-augmented training of limb control improved significantly balance, walking speed, ambulation, and muscle strength in patients. Retention of clinical improvements was confirmed by the 3–4 months follow-up. In patients relative to controls, VBM revealed reductions of white matter volume within the brainstem and cerebellum and VBCT showed cortical thinning in the primary motor cortex. Over time, TBM revealed significant improvement-induced volume increases in the left middle temporal and occipital gyrus, left temporal pole and fusiform gyrus, both hippocampi, cerebellum, corpus callosum, and brainstem in iSCI patients. This study demonstrates structural plasticity at the cortical and brainstem level as a consequence of VR-augmented training in iSCI patients. These structural changes may serve as neuroimaging biomarkers of VR-augmented lower limb neurorehabilitation in addition to performance measures to detect improvements in rehabilitative training. PMID:25999842

  6. Effects of TRPV1 on the hippocampal synaptic plasticity in the epileptic rat brain.

    PubMed

    Saffarzadeh, Fatemeh; Eslamizade, Mohammad J; Ghadiri, Tahereh; Modarres Mousavi, Sayed Mostafa; Hadjighassem, Mahmoudreza; Gorji, Ali

    2015-07-01

    Temporal lobe epilepsy is often presented by medically intractable recurrent seizures due to dysfunction of temporal lobe structures, mostly the temporomesial structures. The role of transient receptor potential vaniloid 1 (TRPV1) activity on synaptic plasticity of the epileptic brain tissues was investigated. We studied hippocampal TRPV1 protein content and distribution in the hippocampus of epileptic rats. Furthermore, the effects of pharmacologic modulation of TRPV1 receptors on field excitatory postsynaptic potentials have been analyzed after induction of long term potentiation (LTP) in the hippocampal CA1 and CA3 areas after 1 day (acute phase) and 3 months (chronic phase) of pilocarpine-induced status epilepticus (SE). A higher expression of TRPV1 protein in the hippocampus as well as a higher distribution of this channel in CA1 and CA3 areas in both acute and chronic phases of pilocarpine-induced SE was observed. Activation of TRPV1 using capsaicin (1 µM) enhanced LTP induction in CA1 region in non-epileptic rats. Inhibition of TRPV1 by capsazepine (10 µM) did not affect LTP induction in non-epileptic rats. In acute phase of SE, activation of TRPV1 enhanced LTP in both CA1 and CA3 areas but TRPV1 inhibition did not affect LTP. In chronic phase of SE, application of TRPV1 antagonist enhanced LTP induction in CA1 and CA3 regions but TRPV1 activation had no effect on LTP. These findings indicate that a higher expression of TRPV1 in epileptic conditions is accompanied by a functional impact on the synaptic plasticity in the hippocampus. This suggests TRPV1 as a potential target in treatment of seizure attacks. Synapse 69:375-383, 2015. © 2015 Wiley Periodicals, Inc. PMID:25967571

  7. Effects of plasticizers and plastic bags on granulocyte function during storage.

    PubMed

    Miyamoto, M; Sasakawa, S

    1987-01-01

    The influence of the plasticizers, di-(2-ethylhexyl)phthalate (DEHP) and tri-(2-ethylhexyl)trimellitate (TOTM), on granulocyte function was examined. Polyvinyl chloride (PVC) bags with DEHP (DEHP-PVC) leaked DEHP into plasma, but TOTM did not dissolve in plasma under the same conditions. Glow discharge treatment inhibited the leakage of DEHP from DEHP-PVC bags. Depending on the amount of DEHP added into granulocyte suspension, chemotaxis and bactericidal activity decreased, but cell counts and phagocytosis were not affected. During storage for 24 h at 22 degrees C, granulocyte function decreased greatly in DEHP-PVC, but was well maintained in the bags which did not leak plasticizers, TOTM-PVC and glow-discharged DEHP-PVC. PMID:3660766

  8. White matter in the older brain is more plastic than in the younger brain

    PubMed Central

    Yotsumoto, Yuko; Chang, Li-Hung; Ni, Rui; Pierce, Russell; Andersen, George J; Watanabe, Takeo; Sasaki, Yuka

    2014-01-01

    Visual perceptual learning (VPL) with younger subjects is associated with changes in functional activation of the early visual cortex. Although overall brain properties decline with age, it is unclear whether these declines are associated with visual perceptual learning. Here we use diffusion tensor imaging to test whether changes in white matter are involved in VPL for older adults. After training on a texture discrimination task for 3 daily sessions, both older and younger subjects show performance improvements. While the older subjects show significant changes in fractional anisotropy (FA) in the white matter beneath the early visual cortex after training, no significant change in FA is observed for younger subjects. These results suggest that the mechanism for VPL in older individuals is considerably different from that in younger individuals and that VPL of older individuals involves re-organization of white matter. PMID:25407566

  9. Actin: From structural plasticity to functional diversity

    Microsoft Academic Search

    Cora-Ann Schoenenberger; Hans Georg Mannherz; Brigitte M. Jockusch

    2011-01-01

    This article addresses the multiple activities of actin. Starting out with the history of actin's discovery, purification and structure, it emphasizes the close relation between structure and function. In this context, we also point to unconventional actin conformations. Their existence in living cells is not yet well documented, however, they seem to play a special role in the supramolecular patterning

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

    Microsoft Academic Search

    João Pedro de Magalhães; Anders Sandberg

    2005-01-01

    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

  11. Emergence of Functional Specificity in Balanced Networks with Synaptic Plasticity

    PubMed Central

    Sadeh, Sadra; Clopath, Claudia; Rotter, Stefan

    2015-01-01

    In rodent visual cortex, synaptic connections between orientation-selective neurons are unspecific at the time of eye opening, and become to some degree functionally specific only later during development. An explanation for this two-stage process was proposed in terms of Hebbian plasticity based on visual experience that would eventually enhance connections between neurons with similar response features. For this to work, however, two conditions must be satisfied: First, orientation selective neuronal responses must exist before specific recurrent synaptic connections can be established. Second, Hebbian learning must be compatible with the recurrent network dynamics contributing to orientation selectivity, and the resulting specific connectivity must remain stable for unspecific background activity. Previous studies have mainly focused on very simple models, where the receptive fields of neurons were essentially determined by feedforward mechanisms, and where the recurrent network was small, lacking the complex recurrent dynamics of large-scale networks of excitatory and inhibitory neurons. Here we studied the emergence of functionally specific connectivity in large-scale recurrent networks with synaptic plasticity. Our results show that balanced random networks, which already exhibit highly selective responses at eye opening, can develop feature-specific connectivity if appropriate rules of synaptic plasticity are invoked within and between excitatory and inhibitory populations. If these conditions are met, the initial orientation selectivity guides the process of Hebbian learning and, as a result, functionally specific and a surplus of bidirectional connections emerge. Our results thus demonstrate the cooperation of synaptic plasticity and recurrent dynamics in large-scale functional networks with realistic receptive fields, highlight the role of inhibition as a critical element in this process, and paves the road for further computational studies of sensory processing in neocortical network models equipped with synaptic plasticity. PMID:26090844

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

    PubMed Central

    Cleeremans, Axel

    2011-01-01

    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. PMID:21687455

  13. Lrp4 Domains Differentially Regulate Limb/Brain Development and Synaptic Plasticity

    PubMed Central

    Pohlkamp, Theresa; Durakoglugil, Murat; Lane-Donovan, Courtney; Xian, Xunde; Johnson, Eric B.; Hammer, Robert E.; Herz, Joachim

    2015-01-01

    Apolipoprotein E (ApoE) genotype is the strongest predictor of Alzheimer’s Disease (AD) risk. ApoE is a cholesterol transport protein that binds to members of the Low-Density Lipoprotein (LDL) Receptor family, which includes LDL Receptor Related Protein 4 (Lrp4). Lrp4, together with one of its ligands Agrin and its co-receptors Muscle Specific Kinase (MuSK) and Amyloid Precursor Protein (APP), regulates neuromuscular junction (NMJ) formation. All four proteins are also expressed in the adult brain, and APP, MuSK, and Agrin are required for normal synapse function in the CNS. Here, we show that Lrp4 is also required for normal hippocampal plasticity. In contrast to the closely related Lrp8/Apoer2, the intracellular domain of Lrp4 does not appear to be necessary for normal expression and maintenance of long-term potentiation at central synapses or for the formation and maintenance of peripheral NMJs. However, it does play a role in limb development. PMID:25688974

  14. Functional brain network efficiency predicts intelligence.

    PubMed

    Langer, Nicolas; Pedroni, Andreas; Gianotti, Lorena R R; Hänggi, Jürgen; Knoch, Daria; Jäncke, Lutz

    2012-06-01

    The neuronal causes of individual differences in mental abilities such as intelligence are complex and profoundly important. Understanding these abilities has the potential to facilitate their enhancement. The purpose of this study was to identify the functional brain network characteristics and their relation to psychometric intelligence. In particular, we examined whether the functional network exhibits efficient small-world network attributes (high clustering and short path length) and whether these small-world network parameters are associated with intellectual performance. High-density resting state electroencephalography (EEG) was recorded in 74 healthy subjects to analyze graph-theoretical functional network characteristics at an intracortical level. Ravens advanced progressive matrices were used to assess intelligence. We found that the clustering coefficient and path length of the functional network are strongly related to intelligence. Thus, the more intelligent the subjects are the more the functional brain network resembles a small-world network. We further identified the parietal cortex as a main hub of this resting state network as indicated by increased degree centrality that is associated with higher intelligence. Taken together, this is the first study that substantiates the neural efficiency hypothesis as well as the Parieto-Frontal Integration Theory (P-FIT) of intelligence in the context of functional brain network characteristics. These theories are currently the most established intelligence theories in neuroscience. Our findings revealed robust evidence of an efficiently organized resting state functional brain network for highly productive cognitions. PMID:21557387

  15. Advantages in functional imaging of the brain

    PubMed Central

    Mier, Walter; Mier, Daniela

    2015-01-01

    As neuronal pathologies cause only minor morphological alterations, molecular imaging techniques are a prerequisite for the study of diseases of the brain. The development of molecular probes that specifically bind biochemical markers and the advances of instrumentation have revolutionized the possibilities to gain insight into the human brain organization and beyond this—visualize structure-function and brain-behavior relationships. The review describes the development and current applications of functional brain imaging techniques with a focus on applications in psychiatry. A historical overview of the development of functional imaging is followed by the portrayal of the principles and applications of positron emission tomography (PET) and functional magnetic resonance imaging (fMRI), two key molecular imaging techniques that have revolutionized the ability to image molecular processes in the brain. We conclude that the juxtaposition of PET and fMRI in hybrid PET/MRI scanners enhances the significance of both modalities for research in neurology and psychiatry and might pave the way for a new area of personalized medicine. PMID:26042013

  16. Plasticity of inhibitory synapses in the brain: a possible memory mechanism that has been overlooked

    Microsoft Academic Search

    Masanobu Kano

    1995-01-01

    Long-term modification of transmission efficacy at inhibitory synapses has recently been discovered in several regions of the vertebrate brain, i.e. Mauthner cells of the goldfish, cerebellar Purkinje cells, deep cerebellar nuclei and the visual cortex. Synaptic plasticity at inhibitory synapses has properties similar to that of excitatory synapses, such as dependency on intracellular Ca2+ levels, input specificity, saturation and associativity.

  17. An outline of brain function.

    PubMed

    Gilbert, P F

    2001-08-01

    An outline of how the brain may compute is proposed. In the cerebral cortex memories are stored through long-term potentiation at synapses from layer 1 cortical inputs (representing contexts) on layer 2/3 pyramidal cells linked with the thalamus in a cortico-thalamic (CT) unit. The signals which are memorized are the layer 3 inputs from the thalamus or other cortical areas. Signals are memorized (and later recalled) at the gamma frequency. A conscious thought comprises the outputs of layer 5 cells in CT units in different cortical regions firing in synchrony through the contribution of oscillatory thalamic and cortical inputs. This cortical output influences sub-cortical areas to cause or participate in a movement. Cerebral cortical outputs may be stored in the cerebellum and generated later in a particular context by the basal ganglia and cerebellum. Thus the brain may either generate 'conscious' outputs using the cerebral cortex or 'automatic' outputs using the basal ganglia and cerebellum. When contexts are recognized by the basal ganglia it permits outputs stored in the cerebellum to commence and in this way the basal ganglia can control complex sequences of outputs or movements. Working memory involves the prefrontal cortex using similarly the basal ganglia and cerebellum. The hippocampus has a role in the storage and recall of cortical outputs by providing unique layer 1 contexts to all the CT loops in different cortical areas in a conscious thought. With further recall of the thought new layer 1 contexts may become associated with the CT loops enabling recall without the hippocampal input. PMID:11489610

  18. Maintaining older brain functionality: A targeted review.

    PubMed

    Ballesteros, Soledad; Kraft, Eduard; Santana, Silvina; Tziraki, Chariklia

    2015-08-01

    The unprecedented growth in the number of older adults in our society is accompanied by the exponential increase in the number of elderly people who will suffer cognitive decline and dementia in the next decades. This will create an enormous cost for governments, families and individuals. Brain plasticity and its role in brain adaptation to the process of aging is influenced by other changes as a result of co-morbidities, environmental factors, personality traits (psychosocial variables) and genetic and epigenetic factors. This review summarizes recent findings obtained mostly from interventional studies that aim to prevent and/or delay age-related cognitive decline in healthy adults. There are a multitude of such studies. In this paper, we focused our review on physical activity, computerized cognitive training and social enhancement interventions on improving cognition, physical health, independent living and wellbeing of older adults. The methodological limitations of some of these studies, and the need for new multi-domain synergistic interventions, based on current advances in neuroscience and social-brain theories, are discussed. PMID:26054789

  19. Functional transcranial brain imaging by optical-resolution photoacoustic microscopy

    NASA Astrophysics Data System (ADS)

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

    2009-07-01

    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.

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

    Microsoft Academic Search

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

    2009-01-01

    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.

  1. Brain Connectivity Plasticity in the Motor Network after Ischemic Stroke

    PubMed Central

    Jiang, Lin; Xu, Huijuan

    2013-01-01

    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

  2. Whole-Brain Functional Connectivity Identification of Functional Dyspepsia

    PubMed Central

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

    2013-01-01

    Recent neuroimaging studies have shown local brain aberrations in functional dyspepsia (FD) patients, yet little attention has been paid to the whole-brain resting-state functional network abnormalities. The purpose of this study was to investigate whether FD disrupts the patterns of whole-brain networks and the abnormal functional connectivity could reflect the severity of the disease. The dysfunctional interactions between brain regions at rest were investigated in FD patients as compared with 40 age- and gender- matched healthy controls. Multivariate pattern analysis was used to evaluate the discriminative power of our results for classifying patients from controls. In our findings, the abnormal brain functional connections were mainly situated within or across the limbic/paralimbic system, the prefrontal cortex, the tempo-parietal areas and the visual cortex. About 96% of the subjects among the original dataset were correctly classified by a leave one-out cross-validation approach, and 88% accuracy was also validated in a replication dataset. The classification features were significantly associated with the patients’ dyspepsia symptoms, the self-rating depression scale and self-rating anxiety scale, but it was not correlated with duration of FD patients (p>0.05). Our results may indicate the effectiveness of the altered brain functional connections reflecting the disease pathophysiology underling FD. These dysfunctional connections may be the epiphenomena or causative agents of FD, which may be affected by clinical severity and its related emotional dimension of the disease rather than the clinical course. PMID:23799056

  3. Integrating synaptic plasticity and striatal circuit function in addiction.

    PubMed

    Grueter, Brad A; Rothwell, Patrick E; Malenka, Robert C

    2012-06-01

    Exposure to addictive drugs causes changes in synaptic function within the striatal complex, which can either mimic or interfere with the induction of synaptic plasticity. These synaptic adaptations include changes in the nucleus accumbens (NAc), a ventral striatal subregion important for drug reward and reinforcement, as well as the dorsal striatum, which may promote habitual drug use. As the behavioral effects of drugs of abuse are long-lasting, identifying persistent changes in striatal circuits induced by in vivo drug experience is of considerable importance. Within the striatum, drugs of abuse have been shown to induce modifications in dendritic morphology, ionotropic glutamate receptors (iGluR) and the induction of synaptic plasticity. Understanding the detailed molecular mechanisms underlying these changes in striatal circuit function will provide insight into how drugs of abuse usurp normal learning mechanisms to produce pathological behavior. PMID:22000687

  4. Integrating Retinoic Acid Signaling with Brain Function

    ERIC Educational Resources Information Center

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

    2009-01-01

    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…

  5. Press Release Fingerprints of higher brain functions

    E-print Network

    Tübingen, Universität

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

  6. On the Relationship Between Lateralized Brain Function and Orienting Asymmetries

    E-print Network

    Ghazanfar, Asif

    areas of the brain (Broca, 1861; Wernicke, 1874). The loci of brain lesions detected by postmortemOn the Relationship Between Lateralized Brain Function and Orienting Asymmetries Christoph Teufel will require a much better understanding of how lateralized brain functions interact with overt behaviors

  7. Remaining Flexible in Old Alliances: Functional Plasticity in Constrained Mutualisms

    PubMed Central

    Wheeler, Diana E.

    2009-01-01

    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. PMID:19435425

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

    NSDL National Science Digital Library

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

    2005-11-08

    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.

  9. Electromagnetic inverse applications for functional brain imaging

    SciTech Connect

    Wood, C.C.

    1997-10-01

    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.

  10. Combined cognitive-psychological-physical intervention induces reorganization of intrinsic functional brain architecture in older adults.

    PubMed

    Zheng, Zhiwei; Zhu, Xinyi; Yin, Shufei; Wang, Baoxi; Niu, Yanan; Huang, Xin; Li, Rui; Li, Juan

    2015-01-01

    Mounting evidence suggests that enriched mental, physical, and socially stimulating activities are beneficial for counteracting age-related decreases in brain function and cognition in older adults. Here, we used functional magnetic resonance imaging (fMRI) to demonstrate the functional plasticity of brain activity in response to a combined cognitive-psychological-physical intervention and investigated the contribution of the intervention-related brain changes to individual performance in healthy older adults. The intervention was composed of a 6-week program of combined activities including cognitive training, Tai Chi exercise, and group counseling. The results showed improved cognitive performance and reorganized regional homogeneity of spontaneous fluctuations in the blood oxygen level-dependent (BOLD) signals in the superior and middle temporal gyri, and the posterior lobe of the cerebellum, in the participants who attended the intervention. Intriguingly, the intervention-induced changes in the coherence of local spontaneous activity correlated with the improvements in individual cognitive performance. Taken together with our previous findings of enhanced resting-state functional connectivity between the medial prefrontal cortex and medial temporal lobe regions following a combined intervention program in older adults, we conclude that the functional plasticity of the aging brain is a rather complex process, and an effective cognitive-psychological-physical intervention is helpful for maintaining a healthy brain and comprehensive cognition during old age. PMID:25810927

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

    PubMed

    Ricciardi, Emiliano; Handjaras, Giacomo; Pietrini, Pietro

    2014-11-01

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

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

    PubMed Central

    2014-01-01

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

  13. Retinoic Acid Signaling in the Functioning Brain

    NSDL National Science Digital Library

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

    2006-02-28

    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.

  14. Generative models, brain function and neuroimaging.

    PubMed

    Friston, K J; Price, C J

    2001-07-01

    The representational capacity and inherent function of any neuron, neuronal population or cortical area in the brain is dynamic and context-sensitive. Functional integration, or interactions among brain systems, that employ driving (bottom up) and backward (top-down) connections, mediate this adaptive and contextual specialisation. A critical consequence is that neuronal responses, in any given cortical area, can represent different things at different times. This can have fundamental implications for the design of brain imaging experiments and the interpretation of their results. Our arguments are developed under generative models of brain function, where higher-level systems provide a prediction of the inputs to lower-level regions. Conflict between the two is resolved by changes in the higher-level representations, which are driven by the ensuing error in lower regions, until the mismatch is "cancelled". From this perspective the specialisation of any region is determined both by bottom-up driving inputs and by top-down predictions. Specialisation is therefore not an intrinsic property of any region but depends on both forward and backward connections with other areas. Because the latter have access to the context in which the inputs are generated they are in a position to modulate the selectivity or specialisation of lower areas. The implications for classical models (e.g., classical receptive fields in electrophysiology, classical specialisation in neuroimaging and connectionism in cognitive models) are severe and suggest these models may provide incomplete accounts of real brain architectures. Here we focus on the implications for cognitive neuroscience in the context of neuroimaging. PMID:11501732

  15. Functional MRI of long-term potentiation: imaging network plasticity

    PubMed Central

    Álvarez-Salvado, Efrén; Pallarés, Vicente; Moreno, Andrea; Canals, Santiago

    2014-01-01

    Neurons are able to express long-lasting and activity-dependent modulations of their synapses. This plastic property supports memory and conveys an extraordinary adaptive value, because it allows an individual to learn from, and respond to, changes in the environment. Molecular and physiological changes at the cellular level as well as network interactions are required in order to encode a pattern of synaptic activity into a long-term memory. While the cellular mechanisms linking synaptic plasticity to memory have been intensively studied, those regulating network interactions have received less attention. Combining high-resolution fMRI and in vivo electrophysiology in rats, we have previously reported a functional remodelling of long-range hippocampal networks induced by long-term potentiation (LTP) of synaptic plasticity in the perforant pathway. Here, we present new results demonstrating an increased bilateral coupling in the hippocampus specifically supported by the mossy cell commissural/associational pathway in response to LTP. This fMRI-measured increase in bilateral connectivity is accompanied by potentiation of the corresponding polysynaptically evoked commissural potential in the contralateral dentate gyrus and depression of the inactive convergent commissural pathway to the ipsilateral dentate. We review these and previous findings in the broader context of memory consolidation. PMID:24298154

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

    PubMed Central

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

    2013-01-01

    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

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

    PubMed

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

    2013-01-01

    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

  18. Magnesium Protects Cognitive Functions and Synaptic Plasticity in Streptozotocin-Induced Sporadic Alzheimer’s Model

    PubMed Central

    Bao, Jian; Wang, Zhi-Hao; Zeng, Juan; Liu, En-Jie; Li, Xiao-Guang; Huang, Rong-Xi; Gao, Di; Li, Meng-Zhu; Zhang, Yao; Liu, Gong-Ping; Wang, Jian-Zhi

    2014-01-01

    Alzheimer’s disease (AD) is characterized by profound synapse loss and impairments of learning and memory. Magnesium affects many biochemical mechanisms that are vital for neuronal properties and synaptic plasticity. Recent studies have demonstrated that the serum and brain magnesium levels are decreased in AD patients; however, the exact role of magnesium in AD pathogenesis remains unclear. Here, we found that the intraperitoneal administration of magnesium sulfate increased the brain magnesium levels and protected learning and memory capacities in streptozotocin-induced sporadic AD model rats. We also found that magnesium sulfate reversed impairments in long-term potentiation (LTP), dendritic abnormalities, and the impaired recruitment of synaptic proteins. Magnesium sulfate treatment also decreased tau hyperphosphorylation by increasing the inhibitory phosphorylation of GSK-3? at serine 9, thereby increasing the activity of Akt at Ser473 and PI3K at Tyr458/199, and improving insulin sensitivity. We conclude that magnesium treatment protects cognitive function and synaptic plasticity by inhibiting GSK-3? in sporadic AD model rats, which suggests a potential role for magnesium in AD therapy. PMID:25268773

  19. Dynamic geometry, brain function modeling, and consciousness.

    PubMed

    Roy, Sisir; Llinás, Rodolfo

    2008-01-01

    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

  20. Neurological Impairment Linked with Cortico-Subcortical Infiltration of Diffuse Low-Grade Gliomas at Initial Diagnosis Supports Early Brain Plasticity

    PubMed Central

    Smits, Anja; Zetterling, Maria; Lundin, Margareta; Melin, Beatrice; Fahlström, Markus; Grabowska, Anna; Larsson, Elna-Marie; Berntsson, Shala Ghaderi

    2015-01-01

    Diffuse low-grade gliomas (DLGG) are slow-growing brain tumors that in spite of an indolent behavior at onset show a continuous expansion over time and inevitably transform into malignant gliomas. Extensive tumor resections may be performed with preservation of neurological function due to neuroplasticity that is induced by the slow tumor growth. However, DLGG prefer to migrate along subcortical pathways, and white matter plasticity is considerably more limited than gray matter plasticity. Whether signs of functional decompensating white matter that may be found as early as at disease presentation has not been systematically studied. Here, we examined 52 patients who presented with a DLGG at the time of radiological diagnosis. We found a significant correlation between neurological impairment and eloquent cortico-subcortical tumor localization, but not between neurological function and tumor volume. These results suggest that even small tumors invading white matter pathways may lack compensatory mechanisms for functional reorganization already at disease presentation.

  1. Functional brain imaging in respiratory medicine.

    PubMed

    Pattinson, Kyle

    2015-06-01

    Discordance of clinical symptoms with markers of disease severity remains a conundrum in a variety of respiratory conditions. The breathlessness of chronic lung disease correlates poorly with spirometry, yet is a better predictor of mortality. In chronic cough, symptoms are often evident without clear physical cause. In asthma, the terms 'over perceivers' and 'under perceivers' are common parlance. In all these examples, aberrant brain mechanisms may explain the mismatch between symptoms and pathology. Functional MRI is a non-invasive method of measuring brain function. It has recently become significantly advanced enough to be useful in clinical research and to address these potential mechanisms. This article explains how FMRI works, current understanding from FMRI in breathlessness, cough and asthma and suggests possibilities for future research. PMID:25589519

  2. When “altering brain function” becomes “mind control”

    PubMed Central

    Koivuniemi, Andrew; Otto, Kevin

    2014-01-01

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

  3. Exercise but not (-)-Epigallocatechin-3-gallate or ?-Alanine enhances physical fitness, brain plasticity, and behavioral performance in mice

    PubMed Central

    Bhattacharya, Tushar K.; Pence, Brandt D.; Ossyra, Jessica M.; Gibbons, Trisha E.; Perez, Samuel; McCusker, Robert H.; Kelley, Keith W.; Johnson, Rodney W.; Woods, Jeffrey A.; Rhodes, Justin S.

    2015-01-01

    Nutrition and physical exercise can enhance cognitive function but the specific combinations of dietary bioactives that maximize pro-cognitive effects are not known nor are the contributing neurobiological mechanisms. Epigallocatechin-3-gallate (EGCG) is a flavonoid constituent of many plants with high levels found in green tea. EGCG has anti-inflammatory and anti-oxidant properties and is known to cross the blood brain barrier where it can affect brain chemistry and physiology. ?-alanine (B-ALA) is a naturally occurring ?–amino acid that could increase cognitive functioning by increasing levels of exercise via increased capacity of skeletal muscle, by crossing the blood brain barrier and acting as a neurotransmitter, or by free radical scavenging in muscle and brain after conversion into carnosine. The objective of this study was to determine the effects of EGCG (? 250 mg/kg/day), B-ALA (?550 mg/kg/day), and their combination with voluntary wheel running exercise on the following outcome measures: body composition, time to fatigue, production of new cells in the granule layer of the dentate gyrus of the hippocampus as a marker for neuronal plasticity, and behavioral performance on the contextual and cued fear conditioning tasks, as measures of associative learning and memory. Young adult male BALB/cJ mice approximately 2 months old were randomized into 8 groups varying the nutritional supplement in their diet and access to running wheels over a 39 day study period. Running increased food intake, decreased fat mass, increased time to exhaustive fatigue, increased numbers of new cells in the granule layer of the hippocampus, and enhanced retrieval of both contextual and cued fear memories. The diets had no effect on their own or in combination with exercise on any of the fitness, plasticity, and behavioral outcome measures other than B-ALA decreased percent body fat whereas EGCG increased lean body mass slightly. Results suggest that, in young adult BALB/cJ mice, a 39 day treatment of exercise but not dietary supplementation with B-ALA or EGCG, enhances measures of fitness, neuroplasticity and cognition. PMID:25797079

  4. Anatomical plasticity of adult brain is titrated by Nogo Receptor 1.

    PubMed

    Akbik, Feras V; Bhagat, Sarah M; Patel, Pujan R; Cafferty, William B J; Strittmatter, Stephen M

    2013-03-01

    Experience rearranges anatomical connectivity in the brain, but such plasticity is suppressed in adulthood. We examined the turnover of dendritic spines and axonal varicosities in the somatosensory cortex of mice lacking Nogo Receptor 1 (NgR1). Through adolescence, the anatomy and plasticity of ngr1 null mice are indistinguishable from control, but suppression of turnover after age 26 days fails to occur in ngr1-/- mice. Adolescent anatomical plasticity can be restored to 1-year-old mice by conditional deletion of ngr1. Suppression of anatomical dynamics by NgR1 is cell autonomous and is phenocopied by deletion of Nogo-A ligand. Whisker removal deprives the somatosensory cortex of experience-dependent input and reduces dendritic spine turnover in adult ngr1-/- mice to control levels, while an acutely enriched environment increases dendritic spine dynamics in control mice to the level of ngr1-/- mice in a standard environment. Thus, NgR1 determines the low set point for synaptic turnover in adult cerebral cortex. PMID:23473316

  5. When Music and Long-Term Memory Interact: Effects of Musical Expertise on Functional and Structural Plasticity in the Hippocampus

    PubMed Central

    Groussard, Mathilde; La Joie, Renaud; Rauchs, Géraldine; Landeau, Brigitte; Chételat, Gaël; Viader, Fausto; Desgranges, Béatrice; Eustache, Francis; Platel, Hervé

    2010-01-01

    The development of musical skills by musicians results in specific structural and functional modifications in the brain. Surprisingly, no functional magnetic resonance imaging (fMRI) study has investigated the impact of musical training on brain function during long-term memory retrieval, a faculty particularly important in music. Thus, using fMRI, we examined for the first time this process during a musical familiarity task (i.e., semantic memory for music). Musical expertise induced supplementary activations in the hippocampus, medial frontal gyrus, and superior temporal areas on both sides, suggesting a constant interaction between episodic and semantic memory during this task in musicians. In addition, a voxel-based morphometry (VBM) investigation was performed within these areas and revealed that gray matter density of the hippocampus was higher in musicians than in nonmusicians. Our data indicate that musical expertise critically modifies long-term memory processes and induces structural and functional plasticity in the hippocampus. PMID:20957158

  6. Effects of chronic social isolation on Wistar rat behavior and brain plasticity markers.

    PubMed

    Djordjevic, Jelena; Djordjevic, Ana; Adzic, Miroslav; Radojcic, Marija B

    2012-01-01

    Chronic stress is a contributing risk factor in the development of psychiatric illnesses, including depressive disorders. The mechanisms of their psychopathology are multifaceted and include, besides others, alterations in the brain plasticity. Previously, we investigated the effects of chronic social stress in the limbic brain structures of Wistar rats (hippocampus, HIPPO, and prefrontal cortex, PFC) and found multiple characteristics that resembled alterations described in some clinical studies of depression. We extended our investigations and followed the behavior of stressed animals by the open field test (OFT) and forced swimming test (FST), and the expression and polysialylation of synaptic plasticity markers, neural cell adhesion molecule (NCAM) and L1, in the HIPPO and PFC. We also determined the adrenal gland mass and plasma corticosterone (CORT) as a terminal part of the hypothalamic-pituitary-adrenal axis activity. Our data indicated that stressed animals avoided the central zone in the OFT and displayed decreased swimming, but prolonged immobility in the FST. The animals exhibited marked hypertrophy of the adrenal gland cortex, in spite of decreased serum CORT. Simultaneously, the stressed animals exhibited an increase in NCAM mRNA expression in the HIPPO, but not in the PFC. The synaptosomal NCAM of the HIPPO was markedly polysialylated, while cortical PSA-NCAM was significantly decreased. The results showed that chronic social isolation of Wistar rats causes both anxiety-like and depression-like behavior. These alterations are parallel with molecular changes in the limbic brain, including diminished NCAM sialylation in the PFC. Together with our previous results, the current observations suggest that a chronic social isolation model may potentially be used to study molecular mechanisms that underlie depressive symptomatology. PMID:22814229

  7. Order and disorder in the brain function.

    PubMed

    Quadens, Olga

    2003-01-01

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

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

    E-print Network

    Oro, Daniel

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

  9. Maturation of Widely Distributed Brain Function Subserves Cognitive Development

    Microsoft Academic Search

    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

    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

  10. Organization, development and function of complex brain networks

    Microsoft Academic Search

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

    2004-01-01

    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

  11. Mapping distributed brain function and networks with diffuse optical tomography.

    PubMed

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

    2014-06-01

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

  12. [Functional brain lateralization in children: developmental theories and implication for developmental diseases].

    PubMed

    Hommet, C; Billard, C; de Toffol, B; Autret, A

    2003-11-01

    The functional specialization of each hemisphere in adults is now well accepted. Neuropsychology of hemispheric functioning in young children is a more debatable issue and must take into account additional factors such as development and maturation, characterized by complex changes in anatomy and organization. The first part of this review describes the theory behind the development of the functional organization of the brain. Second, we discuss data regarding brain lesions in children with brain damage and with normal development. We comment on the concept of plasticity and the critical period. We also discuss the neurobiological processes underlying the functional organization of the brain in the model of developmental disorders in children. We chose three disorders involving the left hemisphere (developmental dysphasia), both hemispheres (benign rolandic epilepsy) or the right hemisphere (congenital hydrocephalus) in order to examine their relationship to a specific hemispheric functional organization. We used classic neuropsychological tests such as the dichotic listening task, the dichaptic palpation and the time-sharing paradigm. The patterns observed in each pathology are discussed in light of data obtained in children with brain lesions. PMID:14710020

  13. 3D Standard Brain of the Red Flour Beetle Tribolium Castaneum: A Tool to Study Metamorphic Development and Adult Plasticity

    PubMed Central

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

    2009-01-01

    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. PMID:20339482

  14. Brain-derived neurotrophic factor-induced gene expression reveals novel actions of VGF in hippocampal synaptic plasticity.

    PubMed

    Alder, Janet; Thakker-Varia, Smita; Bangasser, Debra A; Kuroiwa, May; Plummer, Mark R; Shors, Tracey J; Black, Ira B

    2003-11-26

    Synaptic strengthening induced by brain-derived neurotrophic factor (BDNF) is associated with learning and is coupled to transcriptional activation. However, identification of the spectrum of genes associated with BDNF-induced synaptic plasticity and the correlation of expression with learning paradigms in vivo has not yet been studied. Transcriptional analysis of BDNF-induced synaptic strengthening in cultured hippocampal neurons revealed increased expression of the immediate early genes (IEGs), c-fos, early growth response gene 1 (EGR1), activity-regulated cytoskeletal-associated protein (Arc) at 20 min, and the secreted peptide VGF (non-acronymic) protein precursor at 3 hr. The induced genes served as prototypes to decipher mechanisms of both BDNF-induced transcription and plasticity. BDNF-mediated gene expression was tyrosine kinase B and mitogen-activated protein kinase-dependent, as demonstrated by pharmacological studies. Single-cell transcriptional analysis of Arc after whole-cell patch-clamp recordings indicated that increased gene expression correlated with enhancement of synaptic transmission by BDNF. Increased expression in vitro predicted elevations in vivo: VGF and the IEGs increased after trace eyeblink conditioning, a hippocampal-dependent learning paradigm. VGF protein was also upregulated by BDNF treatment and was expressed in a punctate manner in dissociated hippocampal neurons. Collectively, these findings suggested that the VGF neuropeptides may regulate synaptic function. We found a novel function for VGF by applying VGF peptides to neurons. C-terminal VGF peptides acutely increased synaptic charge in a dose-dependent manner, whereas N-terminal peptide had no effect. These observations indicate that gene profiling in vitro can reveal new mechanisms of synaptic strengthening associated with learning and memory. PMID:14645472

  15. Brain-Derived Neurotrophic Factor-Induced Gene Expression Reveals Novel Actions of VGF in Hippocampal Synaptic Plasticity

    PubMed Central

    Alder, Janet; Thakker-Varia, Smita; Bangasser, Debra A.; Kuroiwa, May; Plummer, Mark R.; Shors, Tracey J.; Black, Ira B.

    2012-01-01

    Synaptic strengthening induced by brain-derived neurotrophic factor (BDNF) is associated with learning and is coupled to transcriptional activation. However, identification of the spectrum of genes associated with BDNF-induced synaptic plasticity and the correlation of expression with learning paradigms in vivo has not yet been studied. Transcriptional analysis of BDNF-induced synaptic strengthening in cultured hippocampal neurons revealed increased expression of the immediate early genes (IEGs), c-fos, early growth response gene 1 (EGR1), activity-regulated cytoskeletal-associated protein (Arc) at 20 min, and the secreted peptide VGF (non-acronymic) protein precursor at 3 hr. The induced genes served as prototypes to decipher mechanisms of both BDNF-induced transcription and plasticity. BDNF-mediated gene expression was tyrosine kinase B and mitogen-activated protein kinase-dependent, as demonstrated by pharmacological studies. Single-cell transcriptional analysis of Arc after whole-cell patch-clamp recordings indicated that increased gene expression correlated with enhancement of synaptic transmission by BDNF. Increased expression in vitro predicted elevations in vivo: VGF and the IEGs increased after trace eyeblink conditioning, a hippocampal-dependent learning paradigm. VGF protein was also upregulated by BDNF treatment and was expressed in a punctate manner in dissociated hippocampal neurons. Collectively, these findings suggested that the VGF neuropeptides may regulate synaptic function. We found a novel function for VGF by applying VGF peptides to neurons. C-terminal VGF peptides acutely increased synaptic charge in a dose-dependent manner, whereas N-terminal peptide had no effect. These observations indicate that gene profiling in vitro can reveal new mechanisms of synaptic strengthening associated with learning and memory. PMID:14645472

  16. Deterioration of plasticity and metabolic homeostasis in the brain of the UCD-T2DM rat model of naturally occurring type-2 diabetes.

    PubMed

    Agrawal, Rahul; Zhuang, Yumei; Cummings, Bethany P; Stanhope, Kimber L; Graham, James L; Havel, Peter J; Gomez-Pinilla, Fernando

    2014-09-01

    The rising prevalence of type-2 diabetes is becoming a pressing issue based on emerging reports that T2DM can also adversely impact mental health. We have utilized the UCD-T2DM rat model in which the onset of T2DM develops spontaneously across time and can serve to understand the pathophysiology of diabetes in humans. An increased insulin resistance index and plasma glucose levels manifested the onset of T2DM. There was a decrease in hippocampal insulin receptor signaling in the hippocampus, which correlated with peripheral insulin resistance index along the course of diabetes onset (r=-0.56, p<0.01). T2DM increased the hippocampal levels of 4-hydroxynonenal (4-HNE; a marker of lipid peroxidation) in inverse proportion to the changes in the mitochondrial regulator PGC-1?. Disrupted energy homeostasis was further manifested by a concurrent reduction in energy metabolic markers, including TFAM, SIRT1, and AMPK phosphorylation. In addition, T2DM influenced brain plasticity as evidenced by a significant reduction of BDNF-TrkB signaling. These results suggest that the pathology of T2DM in the brain involves a progressive and coordinated disruption of insulin signaling, and energy homeostasis, with profound consequences for brain function and plasticity. All the described consequences of T2DM were attenuated by treatment with the glucagon-like peptide-1 receptor agonist, liraglutide. Similar results to those of liraglutide were obtained by exposing T2DM rats to a food energy restricted diet, which suggest that normalization of brain energy metabolism is a crucial factor to counteract central insulin sensitivity and synaptic plasticity associated with T2DM. PMID:24840661

  17. A default mode of brain function

    Microsoft Academic Search

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

    2001-01-01

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

  18. Possible contributions of a novel form of synaptic plasticity in Aplysia to reward, memory, and their dysfunctions in mammalian brain

    PubMed Central

    Hawkins, Robert D.

    2013-01-01

    Recent studies in Aplysia have identified a new variation of synaptic plasticity in which modulatory transmitters enhance spontaneous release of glutamate, which then acts on postsynaptic receptors to recruit mechanisms of intermediate- and long-term plasticity. In this review I suggest the hypothesis that similar plasticity occurs in mammals, where it may contribute to reward, memory, and their dysfunctions in several psychiatric disorders. In Aplysia, spontaneous release is enhanced by activation of presynaptic serotonin receptors, but presynaptic D1 dopamine receptors or nicotinic acetylcholine receptors could play a similar role in mammals. Those receptors enhance spontaneous release of glutamate in hippocampus, entorhinal cortex, prefrontal cortex, ventral tegmental area, and nucleus accumbens. In all of those brain areas, glutamate can activate postsynaptic receptors to elevate Ca2+ and engage mechanisms of early-phase long-term potentiation (LTP), including AMPA receptor insertion, and of late-phase LTP, including protein synthesis and growth. Thus, presynaptic receptors and spontaneous release may contribute to postsynaptic mechanisms of plasticity in brain regions involved in reward and memory, and could play roles in disorders that affect plasticity in those regions, including addiction, Alzheimer’s disease, schizophrenia, and attention deficit hyperactivity disorder (ADHD). PMID:24049187

  19. Stability and plasticity of auditory brainstem function across the lifespan.

    PubMed

    Skoe, Erika; Krizman, Jennifer; Anderson, Samira; Kraus, Nina

    2015-06-01

    The human auditory brainstem is thought to undergo rapid developmental changes early in life until age ?2 followed by prolonged stability until aging-related changes emerge. However, earlier work on brainstem development was limited by sparse sampling across the lifespan and/or averaging across children and adults. Using a larger dataset than past investigations, we aimed to trace more subtle variations in auditory brainstem function that occur normally from infancy into the eighth decade of life. To do so, we recorded auditory brainstem responses (ABRs) to a click stimulus and a speech syllable (da) in 586 normal-hearing healthy individuals. Although each set of ABR measures (latency, frequency encoding, response consistency, nonstimulus activity) has a distinct developmental profile, across all measures developmental changes were found to continue well past age 2. In addition to an elongated developmental trajectory and evidence for multiple auditory developmental processes, we revealed a period of overshoot during childhood (5-11 years old) for latency and amplitude measures, when the latencies are earlier and the amplitudes are greater than the adult value. Our data also provide insight into the capacity for experience-dependent auditory plasticity at different stages in life and underscore the importance of using age-specific norms in clinical and experimental applications. PMID:24366906

  20. The perimenopausal aging transition in the female rat brain: decline in bioenergetic systems and synaptic plasticity.

    PubMed

    Yin, Fei; Yao, Jia; Sancheti, Harsh; Feng, Tao; Melcangi, Roberto C; Morgan, Todd E; Finch, Caleb E; Pike, Christian J; Mack, Wendy J; Cadenas, Enrique; Brinton, Roberta D

    2015-07-01

    The perimenopause is an aging transition unique to the female that leads to reproductive senescence which can be characterized by multiple neurological symptoms. To better understand potential underlying mechanisms of neurological symptoms of perimenopause, the present study determined genomic, biochemical, brain metabolic, and electrophysiological transformations that occur during this transition using a rat model recapitulating fundamental characteristics of the human perimenopause. Gene expression analyses indicated two distinct aging programs: chronological and endocrine. A critical period emerged during the endocrine transition from regular to irregular cycling characterized by decline in bioenergetic gene expression, confirmed by deficits in fluorodeoxyglucose-positron emission tomography (FDG-PET) brain metabolism, mitochondrial function, and long-term potentiation. Bioinformatic analysis predicted insulin/insulin-like growth factor 1 and adenosine monophosphate-activated protein kinase/peroxisome proliferator-activated receptor gamma coactivator 1 alpha (AMPK/PGC1?) signaling pathways as upstream regulators. Onset of acyclicity was accompanied by a rise in genes required for fatty acid metabolism, inflammation, and mitochondrial function. Subsequent chronological aging resulted in decline of genes required for mitochondrial function and ?-amyloid degradation. Emergence of glucose hypometabolism and impaired synaptic function in brain provide plausible mechanisms of neurological symptoms of perimenopause and may be predictive of later-life vulnerability to hypometabolic conditions such as Alzheimer's. PMID:25921624

  1. Topographic Brain Mapping: A Window on Brain Function?

    ERIC Educational Resources Information Center

    Karniski, Walt M.

    1989-01-01

    The article reviews the method of topographic mapping of the brain's electrical activity. Multiple electroencephalogram (EEG) electrodes and computerized analysis of the EEG signal are used to generate maps of frequency and voltage (evoked potential). This relatively new technique holds promise in the evaluation of children with behavioral and…

  2. A functional role for REM sleep in brain maturation

    Microsoft Academic Search

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

    1995-01-01

    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

  3. Notch Is Required in Adult Drosophila Sensory Neurons for Morphological and Functional Plasticity of the Olfactory Circuit

    PubMed Central

    Struhl, Gary

    2015-01-01

    Olfactory receptor neurons (ORNs) convey odor information to the central brain, but like other sensory neurons were thought to play a passive role in memory formation and storage. Here we show that Notch, part of an evolutionarily conserved intercellular signaling pathway, is required in adult Drosophila ORNs for the structural and functional plasticity of olfactory glomeruli that is induced by chronic odor exposure. Specifically, we show that Notch activity in ORNs is necessary for the odor specific increase in the volume of glomeruli that occurs as a consequence of prolonged odor exposure. Calcium imaging experiments indicate that Notch in ORNs is also required for the chronic odor induced changes in the physiology of ORNs and the ensuing changes in the physiological response of their second order projection neurons (PNs). We further show that Notch in ORNs acts by both canonical cleavage-dependent and non-canonical cleavage-independent pathways. The Notch ligand Delta (Dl) in PNs switches the balance between the pathways. These data define a circuit whereby, in conjunction with odor, N activity in the periphery regulates the activity of neurons in the central brain and Dl in the central brain regulates N activity in the periphery. Our work highlights the importance of experience dependent plasticity at the first olfactory synapse. PMID:26011623

  4. Plasticity of Attentional Functions in Older Adults after Non-Action Video Game Training: A Randomized Controlled Trial

    PubMed Central

    Mayas, Julia; Parmentier, Fabrice B. R.; Andrés, Pilar; Ballesteros, Soledad

    2014-01-01

    A major goal of recent research in aging has been to examine cognitive plasticity in older adults and its capacity to counteract cognitive decline. The aim of the present study was to investigate whether older adults could benefit from brain training with video games in a cross-modal oddball task designed to assess distraction and alertness. Twenty-seven healthy older adults participated in the study (15 in the experimental group, 12 in the control group. The experimental group received 20 1-hr video game training sessions using a commercially available brain-training package (Lumosity) involving problem solving, mental calculation, working memory and attention tasks. The control group did not practice this package and, instead, attended meetings with the other members of the study several times along the course of the study. Both groups were evaluated before and after the intervention using a cross-modal oddball task measuring alertness and distraction. The results showed a significant reduction of distraction and an increase of alertness in the experimental group and no variation in the control group. These results suggest neurocognitive plasticity in the old human brain as training enhanced cognitive performance on attentional functions. Trial Registration ClinicalTrials.gov NCT02007616 PMID:24647551

  5. Structure-function relationships in human brain development

    E-print Network

    Saygin, Zeynep Mevhibe

    2012-01-01

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

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

    PubMed Central

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

    2013-01-01

    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

  7. Cellular and molecular analysis of neuronal structure plasticity in the mammalian cortex

    E-print Network

    Lee, Wei-Chung Allen

    2006-01-01

    Despite decades of evidence for functional plasticity in the adult brain, the role of structural plasticity in its manifestation remains unclear. cpg15 is an activity-regulated gene encoding a membrane-bound ligand that ...

  8. Manifold learning on brain functional networks in aging.

    PubMed

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

    2015-02-01

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

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

    PubMed Central

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

    2014-01-01

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

  10. Brain Plasticity in Speech Training in Native English Speakers Learning Mandarin Tones

    NASA Astrophysics Data System (ADS)

    Heinzen, Christina Carolyn

    The current study employed behavioral and event-related potential (ERP) measures to investigate brain plasticity associated with second-language (L2) phonetic learning based on an adaptive computer training program. The program utilized the acoustic characteristics of Infant-Directed Speech (IDS) to train monolingual American English-speaking listeners to perceive Mandarin lexical tones. Behavioral identification and discrimination tasks were conducted using naturally recorded speech, carefully controlled synthetic speech, and non-speech control stimuli. The ERP experiments were conducted with selected synthetic speech stimuli in a passive listening oddball paradigm. Identical pre- and post- tests were administered on nine adult listeners, who completed two-to-three hours of perceptual training. The perceptual training sessions used pair-wise lexical tone identification, and progressed through seven levels of difficulty for each tone pair. The levels of difficulty included progression in speaker variability from one to four speakers and progression through four levels of acoustic exaggeration of duration, pitch range, and pitch contour. Behavioral results for the natural speech stimuli revealed significant training-induced improvement in identification of Tones 1, 3, and 4. Improvements in identification of Tone 4 generalized to novel stimuli as well. Additionally, comparison between discrimination of across-category and within-category stimulus pairs taken from a synthetic continuum revealed a training-induced shift toward more native-like categorical perception of the Mandarin lexical tones. Analysis of the Mismatch Negativity (MMN) responses in the ERP data revealed increased amplitude and decreased latency for pre-attentive processing of across-category discrimination as a result of training. There were also laterality changes in the MMN responses to the non-speech control stimuli, which could reflect reallocation of brain resources in processing pitch patterns for the across-category lexical tone contrast. Overall, the results support the use of IDS characteristics in training non-native speech contrasts and provide impetus for further research.

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

    E-print Network

    Kanwisher, Nancy

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

  12. The serotonin receptor 7 and the structural plasticity of brain circuits

    PubMed Central

    Volpicelli, Floriana; Speranza, Luisa; di Porzio, Umberto; Crispino, Marianna; Perrone-Capano, Carla

    2014-01-01

    Serotonin (5-hydroxytryptamine, 5-HT) modulates numerous physiological processes in the nervous system. Together with its function as neurotransmitter, 5-HT regulates neurite outgrowth, dendritic spine shape and density, growth cone motility and synapse formation during development. In the mammalian brain 5-HT innervation is virtually ubiquitous and the diversity and specificity of its signaling and function arise from at least 20 different receptors, grouped in 7 classes. Here we will focus on the role 5-HT7 receptor (5-HT7R) in the correct establishment of neuronal cytoarchitecture during development, as also suggested by its involvement in several neurodevelopmental disorders. The emerging picture shows that this receptor is a key player contributing not only to shape brain networks during development but also to remodel neuronal wiring in the mature brain, thus controlling cognitive and emotional responses. The activation of 5-HT7R might be one of the mechanisms underlying the ability of the CNS to respond to different stimuli by modulation of its circuit configuration. PMID:25309369

  13. Evidence for hubs in human functional brain networks

    PubMed Central

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

    2013-01-01

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

  14. Norepinephrine and Neural Plasticity: The Effects of Xylamine on Experience-Induced Changes in Brain Weight, Memory, and Behavior

    Microsoft Academic Search

    S. Benloucif; E. L. Bennett; M. R. Rosenzweig

    1995-01-01

    The hypothesis that norepinephrine (NE) is critically involved in neural plasticity was tested by administering xylamine, (N-2-chloroethyl-2-methylbenzylamine, 50 mg\\/kg ip) a noradrenergic neurotoxin, to young rats prior to maze training or environmentally enriched housing. In saline-treated rats, exposure to enriched conditions significantly increased the weight of occipital, dorsal, and ventral cortices and the remaining brain compared to individually housed rats.

  15. Exploring the impact of plasticity-related recovery after brain damage in a connectionist model of single-word reading

    Microsoft Academic Search

    Stephen R. Welbourne; Matthew A. Lambon Ralph

    2005-01-01

    The effect of retraining a damaged connectionist model of single-word reading was investigated with the aim of establishing\\u000a whether plasticity-related changes occurring during the recovery process can contribute to our understanding of the pattern\\u000a of dissociations found in brain-damaged patients. In particular, we sought to reproduce the strong frequency × consistency\\u000a interactions found in surface dyslexia. A replication of Plaut,

  16. Histone deacetylases govern cellular mechanisms underlying behavioral and synaptic plasticity in the developing and adult brain

    PubMed Central

    Morris, Michael J.; Karra, Aroon S.; Monteggia, Lisa M.

    2010-01-01

    Histone deacetylases (HDACs) are a family of enzymes that alter gene expression patterns by modifying chromatin architecture. There are 11 mammalian HDACs that are classified by homology into four subfamilies, all with distinct expression patterns in brain. Through the use of pharmacological HDAC inhibitors, and more recently HDAC knockout mice, the role of these enzymes in the central nervous system are starting to be elucidated. We will discuss the latest findings on the specific or redundant roles of individual HDACs in brain as well as the impact of HDAC function on complex behavior, with a focus on learning, memory formation, and affective behavior. Potential HDAC-mediated cellular mechanisms underlying those behaviors are discussed. PMID:20555253

  17. Decoding brain states using functional magnetic resonance imaging

    Microsoft Academic Search

    Dongha Lee; Changwon Jang; Hae-Jeong Park

    2011-01-01

    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.

  18. Aluminum exposure impacts brain plasticity and behavior in Atlantic salmon (Salmo salar).

    PubMed

    Grassie, C; Braithwaite, V A; Nilsson, J; Nilsen, T O; Teien, H-C; Handeland, S O; Stefansson, S O; Tronci, V; Gorissen, M; Flik, G; Ebbesson, L O E

    2013-08-15

    Aluminum (Al) toxicity occurs frequently in natural aquatic ecosystems as a result of acid deposition and natural weathering processes. Detrimental effects of Al toxicity on aquatic organisms are well known and can have consequences for survival. Fish exposed to Al in low pH waters will experience physiological and neuroendocrine changes that disrupt homeostasis and alter behavior. To investigate the effects of Al exposure on both the brain and behavior, Atlantic salmon (Salmo salar) kept in water treated with Al (pH 5.7, 0.37±0.04 ?mol 1(-1) Al) for 2 weeks were compared with fish kept in under control conditions (pH 6.7, <0.04 ?mol 1(-1) Al). Fish exposed to Al and acidic conditions had increased Al accumulation in the gills and decreased gill Na(+), K(+)-ATPase activity, which impaired osmoregulatory capacity and caused physiological stress, indicated by elevated plasma cortisol and glucose levels. Here we show for the first time that exposure to Al in acidic conditions also impaired learning performance in a maze task. Al toxicity also reduced the expression of NeuroD1 transcript levels in the forebrain of exposed fish. As in mammals, these data show that exposure to chronic stress, such as acidified Al, can reduce neural plasticity during behavioral challenges in salmon, and may impair the ability to cope with new environments. PMID:23661775

  19. Angiogenesis, neurogenesis and brain recovery of function following injury.

    PubMed

    Xiong, Ye; Mahmood, Asim; Chopp, Michael

    2010-03-01

    Stroke and traumatic brain injury (TBI) are major causes of mortality and morbidity worldwide. Unfortunately, almost all phase III clinical trials of neuroprotective agents for stroke and TBI have demonstrated no benefit, raising concerns regarding the use of neuroprotective strategies alone as therapy for acute brain injuries. Therefore, a compelling need exists to develop treatments that promote both the repair and regeneration of injured brain tissue, and functional recovery. Recent data suggest that strategies to enhance neurogenesis and angiogenesis following brain injuries may provide promising opportunities to improve clinical outcomes and brain functional recovery. This review discusses neurogenesis and angiogenesis in the adult brain following stroke or TBI. Selected cell-based and pharmacological therapies are highlighted that promote neurogenesis and angiogenesis and are designed to restore neurological function after brain injuries. These discoveries emphasize the need for an improved understanding of injury- and therapy-induced neurogenesis and angiogenesis in the adult brain, and suggest that the manipulation of endogenous neural precursors and endothelial cells is a potential therapy for brain injury. PMID:20178043

  20. Development/Plasticity/Repair Functional Maturation of the First Synapse in Olfaction

    E-print Network

    Paris-Sud XI, Université de

    Development/Plasticity/Repair Functional Maturation of the First Synapse in Olfaction: Development, Institut Pasteur, F-75724 Paris Cedex 15, France The first synapse in olfaction undergoes considerable; adult neurogenesis; olfaction; olfactory bulb; synapse; periglomerular cells Introduction The first

  1. In vivo Visuotopic Brain Mapping with Manganese-Enhanced MRI and Resting-State Functional Connectivity MRI

    PubMed Central

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

    2014-01-01

    The rodents are an increasingly important model for understanding the mechanisms of development, plasticity, functional specialization and disease in the visual system. However, limited tools have been available for assessing the structural and functional connectivity of the visual brain network globally, in vivo and longitudinally. There are also ongoing debates on whether functional brain connectivity directly reflects structural brain connectivity. In this study, we explored the feasibility of manganese-enhanced MRI (MEMRI) via 3 different routes of Mn2+ administration for visuotopic brain mapping and understanding of physiological transport in normal and visually deprived adult rats. In addition, resting-state functional connectivity MRI (RSfcMRI) was performed to evaluate the intrinsic functional network and structural-functional relationships in the corresponding anatomical visual brain connections traced by MEMRI. Upon intravitreal, subcortical, and intracortical Mn2+ injection, different topographic and layer-specific Mn enhancement patterns could be revealed in the visual cortex and subcortical visual nuclei along retinal, callosal, cortico-subcortical, transsynaptic and intracortical horizontal connections. Loss of visual input upon monocular enucleation to adult rats appeared to reduce interhemispheric polysynaptic Mn2+ transfer but not intra- or inter-hemispheric monosynaptic Mn2+ transport after Mn2+ injection into visual cortex. In normal adults, both structural and functional connectivity by MEMRI and RSfcMRI was stronger interhemispherically between bilateral primary/secondary visual cortex (V1/V2) transition zones (TZ) than between V1/V2 TZ and other cortical nuclei. Intrahemispherically, structural and functional connectivity was stronger between visual cortex and subcortical visual nuclei than between visual cortex and other subcortical nuclei. The current results demonstrated the sensitivity of MEMRI and RSfcMRI for assessing the neuroarchitecture, neurophysiology and structural-functional relationships of the visual brains in vivo. These may possess great potentials for effective monitoring and understanding of the basic anatomical and functional connections in the visual system during development, plasticity, disease, pharmacological interventions and genetic modifications in future studies. PMID:24394694

  2. Can we observe epigenetic effects on human brain function?

    PubMed

    Nikolova, Yuliya S; Hariri, Ahmad R

    2015-07-01

    Imaging genetics has identified many contributions of DNA sequence variation to individual differences in brain function, behavior, and risk for psychopathology. Recent studies have extended this work beyond the genome by mapping epigenetic differences, specifically gene methylation in peripherally assessed DNA, onto variability in behaviorally and clinically relevant brain function. These data have generated understandable enthusiasm for the potential of such research to illuminate biological mechanisms of risk. We use our research on the effects of genetic and epigenetic variation in the human serotonin transporter on brain function to generate a guardedly optimistic opinion that the available data encourage continued research in this direction, and suggest strategies to promote faster progress. PMID:26051383

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

    Microsoft Academic Search

    Mark H. Johnson; Tobias Grossmann; Kathrin Cohen Kadosh

    2009-01-01

    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

  4. Mapping Functional Brain Development: Building a Social Brain through Interactive Specialization

    ERIC Educational Resources Information Center

    Johnson, Mark H.; Grossmann, Tobias; Kadosh, Kathrin Cohen

    2009-01-01

    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…

  5. Modeling Brain Energy Metabolism and Function: A Multiparametric Monitoring Approach

    Microsoft Academic Search

    Larisa Vatova; Sigal Meilin; Tamar Manor

    Mathematical modeling of brain function is an important tool needed for a better understanding of experimental results and clinical situations. In the present study, we are constructing and testing a mathematical model capable of simulating changes in brain energy metabolism that develop in real time under various pathophysiological conditions. The model incorporates the following pa- rameters: cerebral blood flow, partial

  6. Magnetic resonance imaging mapping of brain function. Human visual cortex

    Microsoft Academic Search

    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

    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

  7. Functional brain imaging of trigeminal neuralgia.

    PubMed

    Moisset, Xavier; Villain, Nicolas; Ducreux, Denis; Serrie, Alain; Cunin, Gérard; Valade, Dominique; Calvino, Bernard; Bouhassira, Didier

    2011-02-01

    We used functional magnetic resonance imaging (fMRI) to analyze changes in brain activity associated with stimulation of the cutaneous trigger zone in patients with classic trigeminal neuralgia (CTN). Fifteen consecutive patients with CTN in the second or third division of the nerve, were included in this study. The fMRI paradigm consisted of light tactile stimuli of the trigger zone and the homologous contralateral area. Stimulation of the affected side induced pain in seven patients, but was not painful in eight patients on the day of the experiment. Painful stimuli were associated with significantly increased activity in the spinal trigeminal nucleus (SpV), thalamus, primary and secondary somatosensory cortices (S1, S2), anterior cingulate cortex (ACC), insula, premotor/motor cortex, prefrontal areas, putamen, hippocampus and brainstem. Nonpainful stimulation of the trigger zone activated all but three of these structures (SpV, brainstem and ACC). After a successful surgical treatment, activation induced by stimulation of the operated side was confined to S1 and S2. Our data demonstrate the pathological hyperexcitability of the trigeminal nociceptive system, including the second order trigeminal sensory neurons during evoked attacks of CTN. Such sensitization may depend on pain modulatory systems involving both the brainstem (i.e. periaqueductal gray and adjacent structures) and interconnected cortical structures (i.e. ACC). The fact that large portions of the classical 'pain neuromatrix' were also activated during nonpainful stimulation of the trigger zone, could reflect a state of maintained sensitization of the trigeminal nociceptive systems in CTN. PMID:20609605

  8. Complex Networks - A Key to Understanding Brain Function

    ScienceCinema

    Olaf Sporns

    2010-01-08

    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.

  9. Complex Networks - A Key to Understanding Brain Function

    SciTech Connect

    Olaf Sporns

    2008-01-23

    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.

  10. Modulation of brain plasticity in stroke: a novel model for neurorehabilitation.

    PubMed

    Di Pino, Giovanni; Pellegrino, Giovanni; Assenza, Giovanni; Capone, Fioravante; Ferreri, Florinda; Formica, Domenico; Ranieri, Federico; Tombini, Mario; Ziemann, Ulf; Rothwell, John C; Di Lazzaro, Vincenzo

    2014-10-01

    Noninvasive brain stimulation (NIBS) techniques can be used to monitor and modulate the excitability of intracortical neuronal circuits. Long periods of cortical stimulation can produce lasting effects on brain function, paving the way for therapeutic applications of NIBS in chronic neurological disease. The potential of NIBS in stroke rehabilitation has been of particular interest, because stroke is the main cause of permanent disability in industrial nations, and treatment outcomes often fail to meet the expectations of patients. Despite promising reports from many clinical trials on NIBS for stroke recovery, the number of studies reporting a null effect remains a concern. One possible explanation is that the interhemispheric competition model--which posits that suppressing the excitability of the hemisphere not affected by stroke will enhance recovery by reducing interhemispheric inhibition of the stroke hemisphere, and forms the rationale for many studies--is oversimplified or even incorrect. Here, we critically review the proposed mechanisms of synaptic and functional reorganization after stroke, and suggest a bimodal balance-recovery model that links interhemispheric balancing and functional recovery to the structural reserve spared by the lesion. The proposed model could enable NIBS to be tailored to the needs of individual patients. PMID:25201238

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

    PubMed Central

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

    2013-01-01

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

  12. Functional improvement after motor training is correlated with synaptic plasticity in rat thalamus.

    PubMed

    Ding, Yuchuan; Li, Jie; Lai, Qin; Azam, Salman; Rafols, José A; Diaz, Fernando G

    2002-12-01

    The goals of this study were to determine whether functional outcome after motor training in rats was linked to synaptic plasticity in thalamus, and whether the Rota-rod apparatus, widely used to test motor function, could be used as an easy and quantitative motor skill training procedure. Adult female Sprague-Dawley rats (n = 39) were evaluated under three training conditions: 1. Movement requiring balance and coordination skills on Rota-rod; 2. simple exercise on treadmill; 3. nontrained controls. Motor function was evaluated by a series of motor tests (foot fault placing, parallel bar crossing, rope and ladder climbing) before and 14 or 28 days after training procedure. Synaptic strength in brain was assessed by synaptophysin immunocytochemistry. After 14 days of training, Rota-rod-trained animals significantly (p < 0.01) improved motor performance, compared to treadmill and nontrained animals. Animals with up to 28 days of simple exercises on the treadmill did not show a significantly improved performance on most motor tasks, except for an improvement in foot fault placing. Intensive synaptophysin immunoreactivity was present in the right but not the left mediodorsal and ventromedial nuclei of thalamus in Rota-rod-trained rats at 14 and 28 days, and in treadmill-trained rats at 28 days. The data suggested that functional outcome is effectively improved by motor skill training rather than by simple exercises, and this may be related, at least partially, to uniquely lateralized synaptogenesis in the thalamus. Both Rota-rod and treadmill could be quantitatively used in rats for motor training of different complexity. PMID:12500709

  13. Plasticity of the mate choice mind: courtship evokes choice-like brain responses in females from a coercive mating system.

    PubMed

    Wang, S M T; Ramsey, M E; Cummings, M E

    2014-04-01

    Female mate choice is fundamental to sexual selection, and determining molecular underpinnings of female preference variation is important for understanding mating character evolution. Previously it was shown that whole-brain expression of a synaptic plasticity marker, neuroserpin, positively correlates with mating bias in the female choice poeciliid, Xiphophorus nigrensis, when exposed to conspecific courting males, whereas this relationship is reversed in Gambusia affinis, a mate coercive poeciliid with no courting males. Here we explore whether species-level differences in female behavioral and brain molecular responses represent 'canalized' or 'plastic' traits. We expose female G. affinis to conspecific males and females, as well as coercive and courting male Poecilia latipinna, for preference assays followed by whole-brain gene expression analyses of neuroserpin, egr-1 and early B. We find positive correlations between gene expression and female preference strength during exposure to courting heterospecific males, but a reversed pattern following exposure to coercive heterospecific males. This suggests that the neuromolecular processes associated with female preference behavior are plastic and responsive to different male phenotypes (courting or coercive) rather than a canalized response linked to mating system. Further, we propose that female behavioral plasticity may involve learning because female association patterns shifted with experience. Compared to younger females, we found larger, more experienced females spend less time near coercive males but associate more with males in the presence of courters. We thus suggest a conserved learning-based neuromolecular process underlying the diversity of female mate preference across the mate choice and coercion-driven mating systems. PMID:24548673

  14. Fish Oil Tied to Better Brain Function in Older Adults

    MedlinePLUS

    ... nlm.nih.gov/medlineplus/news/fullstory_152697.html Fish Oil Tied to Better Brain Function in Older ... 3 fatty acids -- found in many types of fish -- may benefit people at risk for Alzheimer's disease, ...

  15. Functional geometry alignment and localization of brain areas

    E-print Network

    Langs, Georg

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

  16. Functional brain imaging using near-infrared technology

    Microsoft Academic Search

    Meltem Izzetoglu; SCOTT C. BUNCE; Kurtulus Izzetoglu; Banu Onaral; A. K. Pourrezaei

    2007-01-01

    In the last decade, functional near-infrared spectroscopy (fNIR) has been introduced as a new neuroimaging modality with which to conduct functional brain imaging studies [1]?[24]. fNIR technology uses specific wavelengths of light, irradiated through the scalp, to enable the noninvasive measurement of changes in the relative ratios of deoxygenated hemoglobin (deoxy-Hb) and oxygenated hemoglobin (oxy-Hb) during brain activity. This technology

  17. PATH57 Altered structural and functional network connectivity predicts cognitive function after traumatic brain injury

    Microsoft Academic Search

    D Sharp; Powell J Leech R; V Bonnelle; C F Beckmann; X De Boissezon; R Greenwood; K Kinnunen

    2010-01-01

    Traumatic brain injury (TBI) often results in cognitive impairments that limit recovery. The key pathophysiological predictors of recovery are uncertain, but the disruption of brain networks by diffuse axonal injury (DAI) is likely to be important. Here we use MRI to investigate the effect of TBI on structural and functional connections within cognitive brain networks. We studied 21 patients after

  18. Studying brain function with concurrent near-infrared spectroscopy (NIRS) and functional magnetic resonance

    E-print Network

    Fantini, Sergio

    Studying brain function with concurrent near-infrared spectroscopy (NIRS) and functional magnetic collected with a frequency domain experimental apparatus (ISS, Inc., Champaign IL) comprising sixteen laser brain monitor for functional studies. Keywords: Near-infrared spectroscopy, frequency-domain, f

  19. Pericytes control key neurovascular functions and neuronal phenotype in the adult brain and during brain aging

    PubMed Central

    Bell, Robert D.; Winkler, Ethan A.; Sagare, Abhay P.; Singh, Itender; LaRue, Barb; Deane, Rashid; Zlokovic, Berislav V.

    2010-01-01

    SUMMARY Pericytes play a key role in the development of cerebral microcirculation. The exact role of pericytes in the neurovascular unit in the adult brain and during brain aging remains, however, elusive. Using adult viable pericyte-deficient mice, we show that pericyte loss leads to brain vascular damage by two parallel pathways: (1) reduction in brain microcirculation causing diminished brain capillary perfusion, cerebral blood flow and cerebral blood flow responses to brain activation which ultimately mediates chronic perfusion stress and hypoxia, and (2) blood-brain barrier breakdown associated with brain accumulation of serum proteins and several vasculotoxic and/or neurotoxic macromolecules ultimately leading to secondary neuronal degenerative changes. We show that age-dependent vascular damage in pericyte-deficient mice precedes neuronal degenerative changes, learning and memory impairment and the neuroinflammatory response. Thus, pericytes control key neurovascular functions that are necessary for proper neuronal structure and function, and pericytes loss results in a progressive age-dependent vascular-mediated neurodegeneration. PMID:21040844

  20. Connectivity and functional profiling of abnormal brain structures in pedophilia.

    PubMed

    Poeppl, Timm B; Eickhoff, Simon B; Fox, Peter T; Laird, Angela R; Rupprecht, Rainer; Langguth, Berthold; Bzdok, Danilo

    2015-06-01

    Despite its 0.5-1% lifetime prevalence in men and its general societal relevance, neuroimaging investigations in pedophilia are scarce. Preliminary findings indicate abnormal brain structure and function. However, no study has yet linked structural alterations in pedophiles to both connectional and functional properties of the aberrant hotspots. The relationship between morphological alterations and brain function in pedophilia as well as their contribution to its psychopathology thus remain unclear. First, we assessed bimodal connectivity of structurally altered candidate regions using meta-analytic connectivity modeling (MACM) and resting-state correlations employing openly accessible data. We compared the ensuing connectivity maps to the activation likelihood estimation (ALE) maps of a recent quantitative meta-analysis of brain activity during processing of sexual stimuli. Second, we functionally characterized the structurally altered regions employing meta-data of a large-scale neuroimaging database. Candidate regions were functionally connected to key areas for processing of sexual stimuli. Moreover, we found that the functional role of structurally altered brain regions in pedophilia relates to nonsexual emotional as well as neurocognitive and executive functions, previously reported to be impaired in pedophiles. Our results suggest that structural brain alterations affect neural networks for sexual processing by way of disrupted functional connectivity, which may entail abnormal sexual arousal patterns. The findings moreover indicate that structural alterations account for common affective and neurocognitive impairments in pedophilia. The present multimodal integration of brain structure and function analyses links sexual and nonsexual psychopathology in pedophilia. Hum Brain Mapp 36:2374-2386, 2015. © 2015 Wiley Periodicals, Inc. PMID:25733379

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

    E-print Network

    Paris-Sud XI, Université de

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

  2. Frontal brain asymmetry and immune function

    Microsoft Academic Search

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

    1991-01-01

    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

  3. Functional brain connectivity phenotypes for schizophrenia drug discovery.

    PubMed

    Dawson, Neil; Morris, Brian J; Pratt, Judith A

    2015-02-01

    While our knowledge of the pathophysiology of schizophrenia has increased dramatically, this has not translated into the development of new and improved drugs to treat this disorder. Human brain imaging and electrophysiological studies have provided dramatic new insight into the mechanisms of brain dysfunction in the disease, with a swathe of recent studies highlighting the differences in functional brain network and neural system connectivity present in the disorder. Only recently has the value of applying these approaches in preclinical rodent models relevant to the disorder started to be recognised. Here we highlight recent findings of altered functional brain connectivity in preclinical rodent models and consider their relevance to those alterations seen in the brains of schizophrenia patients. Furthermore, we highlight the potential translational value of using the paradigm of functional brain connectivity phenotypes in the context of preclinical schizophrenia drug discovery, as a means both to understand the mechanisms of brain dysfunction in the disorder and to reduce the current high attrition rate in schizophrenia drug discovery. PMID:25567554

  4. Digital media, the developing brain and the interpretive plasticity of neuroplasticity.

    PubMed

    Choudhury, Suparna; McKinney, Kelly A

    2013-04-01

    The use and misuse of digital technologies among adolescents has been the focus of fiery debates among parents, educators, policy-makers and in the media. Recently, these debates have become shaped by emerging data from cognitive neuroscience on the development of the adolescent brain and cognition. "Neuroplasticity" has functioned as a powerful metaphor in arguments both for and against the pervasiveness of digital media cultures that increasingly characterize teenage life. In this paper, we propose that the debates concerning adolescents are the meeting point of two major social anxieties both of which are characterized by the threat of "abnormal" (social) behaviour: existing moral panics about adolescent behaviour in general and the growing alarm about intense, addictive, and widespread media consumption in modern societies. Neuroscience supports these fears but the same kinds of evidence are used to challenge these fears and reframe them in positive terms. Here, we analyze discourses about digital media, the Internet, and the adolescent brain in the scientific and lay literature. We argue that while the evidential basis is thin and ambiguous, it has immense social influence. We conclude by suggesting how we might move beyond the poles of neuro-alarmism and neuro-enthusiasm. By analyzing the neurological adolescent in the digital age as a socially extended mind, firstly, in the sense that adolescent cognition is distributed across the brain, body, and digital media tools and secondly, by viewing adolescent cognition as enabled and transformed by the institution of neuroscience, we aim to displace the normative terms of current debates. PMID:23599391

  5. Standardized environmental enrichment supports enhanced brain plasticity in healthy rats and prevents cognitive impairment in epileptic rats.

    PubMed

    Fares, Raafat P; Belmeguenai, Amor; Sanchez, Pascal E; Kouchi, Hayet Y; Bodennec, Jacques; Morales, Anne; Georges, Béatrice; Bonnet, Chantal; Bouvard, Sandrine; Sloviter, Robert S; Bezin, Laurent

    2013-01-01

    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. PMID:23342033

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

    PubMed Central

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

    2013-01-01

    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. PMID:23342033

  7. Blocking PirB up-regulates spines and functional synapses to unlock visual cortical plasticity and facilitate recovery from amblyopia.

    PubMed

    Bochner, David N; Sapp, Richard W; Adelson, Jaimie D; Zhang, Siyu; Lee, Hanmi; Djurisic, Maja; Syken, Josh; Dan, Yang; Shatz, Carla J

    2014-10-15

    During critical periods of development, the brain easily changes in response to environmental stimuli, but this neural plasticity declines by adulthood. By acutely disrupting paired immunoglobulin-like receptor B (PirB) function at specific ages, we show that PirB actively represses neural plasticity throughout life. We disrupted PirB function either by genetically introducing a conditional PirB allele into mice or by minipump infusion of a soluble PirB ectodomain (sPirB) into mouse visual cortex. We found that neural plasticity, as measured by depriving mice of vision in one eye and testing ocular dominance, was enhanced by this treatment both during the critical period and when PirB function was disrupted in adulthood. Acute blockade of PirB triggered the formation of new functional synapses, as indicated by increases in miniature excitatory postsynaptic current (mEPSC) frequency and spine density on dendrites of layer 5 pyramidal neurons. In addition, recovery from amblyopia--the decline in visual acuity and spine density resulting from long-term monocular deprivation--was possible after a 1-week infusion of sPirB after the deprivation period. Thus, neural plasticity in adult visual cortex is actively repressed and can be enhanced by blocking PirB function. PMID:25320232

  8. Connectomics and new approaches for analyzing human brain functional connectivity.

    PubMed

    Craddock, R Cameron; Tungaraza, Rosalia L; Milham, Michael P

    2015-01-01

    Estimating the functional interactions between brain regions and mapping those connections to corresponding inter-individual differences in cognitive, behavioral and psychiatric domains are central pursuits for understanding the human connectome. The number and complexity of functional interactions within the connectome and the large amounts of data required to study them position functional connectivity research as a "big data" problem. Maximizing the degree to which knowledge about human brain function can be extracted from the connectome will require developing a new generation of neuroimaging analysis algorithms and tools. This review describes several outstanding problems in brain functional connectomics with the goal of engaging researchers from a broad spectrum of data sciences to help solve these problems. Additionally it provides information about open science resources consisting of raw and preprocessed data to help interested researchers get started. PMID:25810900

  9. Human brain functional MRI and DTI visualization with virtual reality

    PubMed Central

    Chen, Bin; Moreland, John; Zhang, Jingyu

    2011-01-01

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

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

    ERIC Educational Resources Information Center

    Teyler, Timothy J.; Fountain, Stephen B.

    1987-01-01

    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)

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

    E-print Network

    Van Mieghem, Piet

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

  12. Effects of elastic and plastic deformations on the electron work function of metals during bending tests

    Microsoft Academic Search

    W. Li; D. Y. Li

    2004-01-01

    The high sensitivity of the electron work function (EWF) to surface conditions has attracted increasing interest in the application of the electron work function (EWF) to investigate tribological phenomena using the Kelvin probing technique. In this study, the correlation between the EWF and both the elastic and plastic deformation of copper and aluminium during bending tests was investigated. It was

  13. Apolipoprotein E ?4 modulates functional brain connectome in Alzheimer's disease.

    PubMed

    Wang, Jinhui; Wang, Xiao; He, Yi; Yu, Xin; Wang, Huali; He, Yong

    2015-05-01

    The apolipoprotein E (APOE) ?4 allele is a well-established genetic risk factor for Alzheimer's disease (AD). Recent research has demonstrated an APOE ?4-mediated modulation of intrinsic functional brain networks in cognitively normal individuals. However, it remains largely unknown whether and how APOE ?4 affects the brain's functional network architecture in patients with AD. Using resting-state functional MRI and graph-theory approaches, we systematically investigated the topological organization of whole-brain functional networks in 16 APOE ?4 carriers and 26 matched noncarriers with AD at three levels: global whole-brain, intermediate module, and regional node/connection. Neuropsychological analysis showed that the APOE ?4 carriers performed worse on delayed memory but better on a late item generation of a verbal fluency task (associated with executive function) than noncarriers. Whole-brain graph analyses revealed that APOE ?4 significantly disrupted whole-brain topological organization as characterized by (i) reduced parallel information transformation efficiency; (ii) decreased intramodular connectivity within the posterior default mode network (pDMN) and intermodular connectivity of the pDMN and executive control network (ECN) with other neuroanatomical systems; and (iii) impaired functional hubs and their rich-club connectivities that primarily involve the pDMN, ECN, and sensorimotor systems. Further simulation analysis indicated that these altered connectivity profiles of the pDMN and ECN largely accounted for the abnormal global network topology. Finally, the changes in network topology exhibited significant correlations with the patients' cognitive performances. Together, our findings suggest that the APOE genotype modulates large-scale brain networks in AD and shed new light on the gene-connectome interaction in this disease. PMID:25619771

  14. Modeling Brain Energy Metabolism and Function: A Multiparametric Monitoring Approach

    Microsoft Academic Search

    Larisa Vatov; Ziv Kizner; Eytan Ruppin; Sigal Meilin; Tamar Manor; Avraham Mayevsky

    2006-01-01

    Mathematical modeling of brain function is an important tool needed for a better understanding of experimental results and\\u000a clinical situations. In the present study, we are constructing and testing a mathematical model capable of simulating changes\\u000a in brain energy metabolism that develop in real time under various pathophysiological conditions. The model incorporates the\\u000a following parameters: cerebral blood flow, partial oxygen

  15. Human Functional Neuroimaging of Brain Changes Associated with Practice

    Microsoft Academic Search

    A. M. Clare Kelly; Hugh Garavan

    2005-01-01

    The discovery that experience-driven changes in the human brain can occur from a neural to a cortical level throughout the lifespan has stimulated a proliferation of research into how neural function changes in response to experience, enabled by neuroimaging methods such as positron emission tomography and functional magnetic resonance imaging. Studies attempt to characterize these changes by examining how practice

  16. RESEARCH Open Access Brain-Computer Interface Controlled Functional

    E-print Network

    Nenadic, Zoran

    RESEARCH Open Access Brain-Computer Interface Controlled Functional Electrical Stimulation System provide only a limited degree of motor function recovery in these individuals, and therefore novel to restore, substitute, or augment lost motor behaviors in patients with neurological injuries. Here, we

  17. Adaptation of Brain Functional and Structural Networks in Aging

    PubMed Central

    Lee, Annie; Ratnarajah, Nagulan; Tuan, Ta Anh; Chen, Shen-Hsing Annabel; Qiu, Anqi

    2015-01-01

    The human brain, especially the prefrontal cortex (PFC), is functionally and anatomically reorganized in order to adapt to neuronal challenges in aging. This study employed structural MRI, resting-state fMRI (rs-fMRI), and high angular resolution diffusion imaging (HARDI), and examined the functional and structural reorganization of the PFC in aging using a Chinese sample of 173 subjects aged from 21 years and above. We found age-related increases in the structural connectivity between the PFC and posterior brain regions. Such findings were partially mediated by age-related increases in the structural connectivity of the occipital lobe within the posterior brain. Based on our findings, it is thought that the PFC reorganization in aging could be partly due to the adaptation to age-related changes in the structural reorganization of the posterior brain. This thus supports the idea derived from task-based fMRI that the PFC reorganization in aging may be adapted to the need of compensation for resolving less distinctive stimulus information from the posterior brain regions. In addition, we found that the structural connectivity of the PFC with the temporal lobe was fully mediated by the temporal cortical thickness, suggesting that the brain morphology plays an important role in the functional and structural reorganization with aging. PMID:25875816

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

    PubMed Central

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

    2014-01-01

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

  19. Apparent plasticity in functional traits determining competitive ability and spatial distribution: a case from desert

    PubMed Central

    Xie, Jiang-Bo; Xu, Gui-Qing; Jenerette, G. Darrel; Bai, Yong-fei; Wang, Zhong-Yuan; Li, Yan

    2015-01-01

    Species competitive abilities and their distributions are closely related to functional traits such as biomass allocation patterns. When we consider how nutrient supply affects competitive abilities, quantifying the apparent and true plasticity in functional traits is important because the allometric relationships among traits are universal in plants. We propose to integrate the notion of allometry and the classical reaction norm into a composite theoretical framework that quantifies the apparent and true plasticity. Combining the framework with a meta-analysis, a series of field surveys and a competition experiment, we aimed to determine the causes of the dune/interdune distribution patterns of two Haloxylon species in the Gurbantonggut Desert. We found that (1) the biomass allocation patterns of both Haloxylon species in responses to environmental conditions were apparent rather than true plasticity and (2) the allometric allocation patterns affected the plants’ competition for soil nutrient supply. A key implication of our results is that the apparent plasticity in functional traits of plants determines their response to environmental change. Without identifying the apparent and true plasticity, we would substantially overestimate the magnitude, duration and even the direction of plant responses in functional traits to climate change. PMID:26190745

  20. Apparent plasticity in functional traits determining competitive ability and spatial distribution: a case from desert.

    PubMed

    Xie, Jiang-Bo; Xu, Gui-Qing; Jenerette, G Darrel; Bai, Yong-Fei; Wang, Zhong-Yuan; Li, Yan

    2015-01-01

    Species competitive abilities and their distributions are closely related to functional traits such as biomass allocation patterns. When we consider how nutrient supply affects competitive abilities, quantifying the apparent and true plasticity in functional traits is important because the allometric relationships among traits are universal in plants. We propose to integrate the notion of allometry and the classical reaction norm into a composite theoretical framework that quantifies the apparent and true plasticity. Combining the framework with a meta-analysis, a series of field surveys and a competition experiment, we aimed to determine the causes of the dune/interdune distribution patterns of two Haloxylon species in the Gurbantonggut Desert. We found that (1) the biomass allocation patterns of both Haloxylon species in responses to environmental conditions were apparent rather than true plasticity and (2) the allometric allocation patterns affected the plants' competition for soil nutrient supply. A key implication of our results is that the apparent plasticity in functional traits of plants determines their response to environmental change. Without identifying the apparent and true plasticity, we would substantially overestimate the magnitude, duration and even the direction of plant responses in functional traits to climate change. PMID:26190745

  1. Functional Clustering Drives Encoding Improvement in a Developing Brain Network during Awake Visual Learning

    E-print Network

    Dunfield, Derek

    Sensory experience drives dramatic structural and functional plasticity in developing neurons. However, for single-neuron plasticity to optimally improve whole-network encoding of sensory information, changes must be ...

  2. Linking structure and function: Information processing in the brain

    SciTech Connect

    Gremillion, M.A.V.

    1990-01-01

    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 well understood. A complex systems approach would be to examine the overall structure and function of the system and to attempt to establish a common framework for information processing interactions. This paper will use the structure-function relationship as a basis for exploring units of information processing. It will examine the brain as a whole, first providing the non-specialists with an short overview of the structure and some of the functions or outputs of the brain. It then very briefly reviews three of the prominent theoretical concepts that have emerged in the last few decades: receptive fields, feature extraction, and parallel processing. Next, it addresses the question of information processing and outlines the structures which have traditionally been proposed to be the basic unit of information processing. An alternative unit on which information processing in the brain might be based is then proposed, and data outlined to support it. Finally, the implications of this different mode of processing are discussed, both for the brain and for other complex systems. 40 refs., 4 figs., 2 tabs.

  3. Assortative mixing in functional brain networks during epileptic seizures

    NASA Astrophysics Data System (ADS)

    Bialonski, Stephan; Lehnertz, Klaus

    2013-09-01

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

  4. Compensatory Plasticity in the Deaf Brain: Effects on Perception of Music

    PubMed Central

    Good, Arla; Reed, Maureen J.; Russo, Frank A.

    2014-01-01

    When one sense is unavailable, sensory responsibilities shift and processing of the remaining modalities becomes enhanced to compensate for missing information. This shift, referred to as compensatory plasticity, results in a unique sensory experience for individuals who are deaf, including the manner in which music is perceived. This paper evaluates the neural, behavioural and cognitive evidence for compensatory plasticity following auditory deprivation and considers how this manifests in a unique experience of music that emphasizes visual and vibrotactile modalities. PMID:25354235

  5. Rapid experience-dependent plasticity of synapse function and structure in ferret visual cortex in vivo

    E-print Network

    Yu, Hongbo

    The rules by which visual experience influences neuronal responses and structure in the developing brain are not well understood. To elucidate the relationship between rapid functional changes and dendritic spine remodeling ...

  6. Democratic reinforcement: A principle for brain function

    SciTech Connect

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

    1995-05-01

    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.

  7. Overexpression of the full-length neurotrophin receptor trkB regulates the expression of plasticity-related genes in mouse brain

    Microsoft Academic Search

    Eija Koponen; Merja Lakso; Eero Castrén

    2004-01-01

    Significant body of evidence indicates an important role for brain-derived neurotrophic factor (BDNF) in the hippocampal synaptic plasticity; however, the exact mechanisms how the BDNF signal is converted to plastic changes during memory processes are under an intense investigation. To specifically address the role of the trkB receptor, we have previously generated transgenic mice overexpressing the full-length trkB receptor and

  8. Task-specific functional brain geometry from model maps.

    PubMed

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

    2008-01-01

    In this paper we propose model maps to derive and represent the intrinsic functional geometry of a brain from functional magnetic resonance imaging (fMRI) data for a specific task. Model maps represent the coherence of behavior of individual fMRI-measurements for a set of observations, or a time sequence. The maps establish a relation between individual positions in the brain by encoding the blood oxygen level dependent (BOLD) signal over a time period in a Markov chain. They represent this relation by mapping spatial positions to a new metric space, the model map. In this map the Euclidean distance between two points relates to the joint modeling behavior of their signals and thus the co-dependencies of the corresponding signals. The map reflects the functional as opposed to the anatomical geometry of the brain. It provides a quantitative tool to explore and study global and local patterns of resource allocation in the brain. To demonstrate the merit of this representation, we report quantitative experimental results on 29 fMRI time sequences, each with sub-sequences corresponding to 4 different conditions for two groups of individuals. We demonstrate that drug abusers exhibit lower differentiation in brain interactivity between baseline and reward related tasks, which could not be quantified until now. PMID:18979834

  9. AUTONOMIC FUNCTION CAN EVALUATE BRAIN STEM FUNCTION TO DETERMINE VIABILITY OF LIFE.: 301

    Microsoft Academic Search

    Joseph Colombo; Kevan Iffrig; Elif Aysin; Ben Aysin; Charles C Wo; William C Shoemaker; Adam Colombo

    2006-01-01

    Introduction: Current methods in evaluating brain function to determine viability of life typically involves brain flow studies after cerebral edema or ischemia has occurred. We present data demonstrating earlier determination of lack of brain stem activity which can lead to earlier clinical decision-making, earlier family involvement in end-of-life issues, including organ donation, and decreased intensive care unit and ventilator-management time

  10. Efficiency and Cost of Economical Brain Functional Networks

    PubMed Central

    Achard, Sophie; Bullmore, Ed

    2007-01-01

    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 = 11; mean age = 66.5 years) and healthy young (N = 15; mean age = 24.7 years) volunteers were each scanned twice in a no-task or “resting” state following placebo or a single dose of a dopamine receptor antagonist (sulpiride 400 mg). Functional connectivity between 90 cortical and subcortical regions was estimated by wavelet correlation analysis, in the frequency interval 0.06–0.11 Hz, and thresholded to construct undirected graphs. These brain functional networks were small-world and economical in the sense of providing high global and local efficiency of parallel information processing for low connection cost. Efficiency was reduced disproportionately to cost in older people, and the detrimental effects of age on efficiency were localised to frontal and temporal cortical and subcortical regions. Dopamine antagonism also impaired global and local efficiency of the network, but this effect was differentially localised and did not interact with the effect of age. Brain functional networks have economical small-world properties—supporting efficient parallel information transfer at relatively low cost—which are differently impaired by normal aging and pharmacological blockade of dopamine transmission. PMID:17274684

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

    PubMed Central

    Srinivasa, Narayan; Jiang, Qin

    2013-01-01

    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

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

    PubMed

    Srinivasa, Narayan; Jiang, Qin

    2013-01-01

    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

  13. Development/Plasticity/Repair A Structural MRI Study of Human Brain Development from

    E-print Network

    Utah, University of

    and schizophrenia. Knowledge regarding this period is currently quite limited. We studied structural brain, with the brain reaching 80­90% of adult volume by age 2 (Pfefferbaum et al., 1994). The rapid elaboration of new after birth. The general pattern of adult myelination is present by the end of the second year (Sampaio

  14. Cortical Overexpression of Neuronal Calcium Sensor-1 Induces Functional Plasticity in Spinal Cord Following Unilateral Pyramidal Tract Injury in Rat

    PubMed Central

    Yip, Ping K.; Wong, Liang-Fong; Sears, Thomas A.; Yáñez-Muñoz, Rafael J.; McMahon, Stephen B.

    2010-01-01

    Following trauma of the adult brain or spinal cord the injured axons of central neurons fail to regenerate or if intact display only limited anatomical plasticity through sprouting. Adult cortical neurons forming the corticospinal tract (CST) normally have low levels of the neuronal calcium sensor-1 (NCS1) protein. In primary cultured adult cortical neurons, the lentivector-induced overexpression of NCS1 induces neurite sprouting associated with increased phospho-Akt levels. When the PI3K/Akt signalling pathway was pharmacologically inhibited the NCS1-induced neurite sprouting was abolished. The overexpression of NCS1 in uninjured corticospinal neurons exhibited axonal sprouting across the midline into the CST-denervated side of the spinal cord following unilateral pyramidotomy. Improved forelimb function was demonstrated behaviourally and electrophysiologically. In injured corticospinal neurons, overexpression of NCS1 induced axonal sprouting and regeneration and also neuroprotection. These findings demonstrate that increasing the levels of intracellular NCS1 in injured and uninjured central neurons enhances their intrinsic anatomical plasticity within the injured adult central nervous system. PMID:20585375

  15. Functional near-infrared spectroscopy maps cortical plasticity underlying altered motor performance induced by transcranial direct current stimulation

    PubMed Central

    Khan, Bilal; Hodics, Timea; Hervey, Nathan; Kondraske, George; Stowe, Ann M.; Alexandrakis, George

    2013-01-01

    Abstract. Transcranial direct current stimulation (tDCS) of the human sensorimotor cortex during physical rehabilitation induces plasticity in the injured brain that improves motor performance. Bi-hemispheric tDCS is a noninvasive technique that modulates cortical activation by delivering weak current through a pair of anodal–cathodal (excitation–suppression) electrodes, placed on the scalp and centered over the primary motor cortex of each hemisphere. To quantify tDCS-induced plasticity during motor performance, sensorimotor cortical activity was mapped during an event-related, wrist flexion task by functional near-infrared spectroscopy (fNIRS) before, during, and after applying both possible bi-hemispheric tDCS montages in eight healthy adults. Additionally, torque applied to a lever device during isometric wrist flexion and surface electromyography measurements of major muscle group activity in both arms were acquired concurrently with fNIRS. This multiparameter approach found that hemispheric suppression contralateral to wrist flexion changed resting-state connectivity from intra-hemispheric to inter-hemispheric and increased flexion speed (p<0.05). Conversely, exciting this hemisphere increased opposing muscle output resulting in a decrease in speed but an increase in accuracy (p<0.05 for both). The findings of this work suggest that tDCS with fNIRS and concurrent multimotor measurements can provide insights into how neuroplasticity changes muscle output, which could find future use in guiding motor rehabilitation. PMID:24193947

  16. Structural and functional brain rewiring clarifies preserved interhemispheric transfer in humans born without the corpus callosum

    PubMed Central

    Tovar-Moll, Fernanda; Monteiro, Myriam; Andrade, Juliana; Bramati, Ivanei E.; Vianna-Barbosa, Rodrigo; Marins, Theo; Rodrigues, Erika; Dantas, Natalia; Behrens, Timothy E. J.; de Oliveira-Souza, Ricardo; Moll, Jorge; Lent, Roberto

    2014-01-01

    Why do humans born without the corpus callosum, the major interhemispheric commissure, lack the disconnection syndrome classically described in callosotomized patients? This paradox was discovered by Nobel laureate Roger Sperry in 1968, and has remained unsolved since then. To tackle the hypothesis that alternative neural pathways could explain this puzzle, we investigated patients with callosal dysgenesis using structural and functional neuroimaging, as well as neuropsychological assessments. We identified two anomalous white-matter tracts by deterministic and probabilistic tractography, and provide supporting resting-state functional neuroimaging and neuropsychological evidence for their functional role in preserved interhemispheric transfer of complex tactile information, such as object recognition. These compensatory pathways connect the homotopic posterior parietal cortical areas (Brodmann areas 39 and surroundings) via the posterior and anterior commissures. We propose that anomalous brain circuitry of callosal dysgenesis is determined by long-distance plasticity, a set of hardware changes occurring in the developing brain after pathological interference. So far unknown, these pathological changes somehow divert growing axons away from the dorsal midline, creating alternative tracts through the ventral forebrain and the dorsal midbrain midline, with partial compensatory effects to the interhemispheric transfer of cortical function. PMID:24821757

  17. Netrin 1 regulates blood-brain barrier function and neuroinflammation.

    PubMed

    Podjaski, Cornelia; Alvarez, Jorge I; Bourbonniere, Lyne; Larouche, Sandra; Terouz, Simone; Bin, Jenea M; Lécuyer, Marc-André; Saint-Laurent, Olivia; Larochelle, Catherine; Darlington, Peter J; Arbour, Nathalie; Antel, Jack P; Kennedy, Timothy E; Prat, Alexandre

    2015-06-01

    Blood-brain barrier function is driven by the influence of astrocyte-secreted factors. During neuroinflammatory responses the blood-brain barrier is compromised resulting in central nervous system damage and exacerbated pathology. Here, we identified endothelial netrin 1 induction as a vascular response to astrocyte-derived sonic hedgehog that promotes autocrine barrier properties during homeostasis and increases with inflammation. Netrin 1 supports blood-brain barrier integrity by upregulating endothelial junctional protein expression, while netrin 1 knockout mice display disorganized tight junction protein expression and barrier breakdown. Upon inflammatory conditions, blood-brain barrier endothelial cells significantly upregulated netrin 1 levels in vitro and in situ, which prevented junctional breach and endothelial cell activation. Finally, netrin 1 treatment during experimental autoimmune encephalomyelitis significantly reduced blood-brain barrier disruption and decreased clinical and pathological indices of disease severity. Our results demonstrate that netrin 1 is an important regulator of blood-brain barrier maintenance that protects the central nervous system against inflammatory conditions such as multiple sclerosis and experimental autoimmune encephalomyelitis. PMID:25903786

  18. Brain-derived neurotrophic factor/TrkB signaling regulates daily astroglial plasticity in the suprachiasmatic nucleus: electron-microscopic evidence in mouse.

    PubMed

    Girardet, Clémence; Lebrun, Bruno; Cabirol-Pol, Marie-Jeanne; Tardivel, Catherine; François-Bellan, Anne-Marie; Becquet, Denis; Bosler, Olivier

    2013-07-01

    Synchronization of circadian rhythms to the 24-h light/dark (L/D) cycle is associated with daily rearrangements of the neuronal-glial network of the suprachiasmatic nucleus of the hypothalamus (SCN), the central master clock orchestrating biological functions in mammals. These anatomical plastic events involve neurons synthesizing vasoactive intestinal peptide (VIP), known as major integrators of photic signals in the retinorecipient region of the SCN. Using an analog-sensitive kinase allele murine model (TrkB(F616A) ), we presently show that the pharmacological blockade of the tropomyosin-related kinase receptor type B (TrkB), the high-affinity receptor of brain-derived neurotrophic factor (BDNF), abolished day/night changes in the dendrite enwrapping of VIP neurons by astrocytic processes (glial coverage), used as an index of SCN plasticity on electron-microscopic sections. Therefore, the BDNF/TrkB signaling pathway exerts a permissive role on the ultrastructural rearrangements that occur in SCN under L/D alternance, an action that could be a critical determinant of the well-established role played by BDNF in the photic regulation of the SCN. In contrast, the extent of glial coverage of non-VIP neighboring dendrites was not different at daytime and nighttime in TrkB(F616A) mice submitted to TrkB inactivation or not receiving any pharmacological treatment. These data not only show that BDNF regulates SCN structural plasticity across the 24-h cycle but also reinforce the view that the daily changes in SCN architecture subserve the light synchronization process. PMID:23640807

  19. Rapid plasticity of dendritic spine: hints to possible functions? Menahem Segal*

    E-print Network

    Segal, Menahem

    Rapid plasticity of dendritic spine: hints to possible functions? Menahem Segal* Department that dendritic spines are stable storage sites of long term memory, the emerging picture from a recent ¯urry. Concurrently, the nature of stimuli which cause formation or collapse of dendritic spines has changed from

  20. Functional MRI during Hippocampal Deep Brain Stimulation in the Healthy Rat Brain

    PubMed Central

    Van Den Berge, Nathalie; Vanhove, Christian; Descamps, Benedicte; Dauwe, Ine; van Mierlo, Pieter; Vonck, Kristl; Keereman, Vincent; Raedt, Robrecht; Boon, Paul; Van Holen, Roel

    2015-01-01

    Deep Brain Stimulation (DBS) is a promising treatment for neurological and psychiatric disorders. The mechanism of action and the effects of electrical fields administered to the brain by means of an electrode remain to be elucidated. The effects of DBS have been investigated primarily by electrophysiological and neurochemical studies, which lack the ability to investigate DBS-related responses on a whole-brain scale. Visualization of whole-brain effects of DBS requires functional imaging techniques such as functional Magnetic Resonance Imaging (fMRI), which reflects changes in blood oxygen level dependent (BOLD) responses throughout the entire brain volume. In order to visualize BOLD responses induced by DBS, we have developed an MRI-compatible electrode and an acquisition protocol to perform DBS during BOLD fMRI. In this study, we investigate whether DBS during fMRI is valuable to study local and whole-brain effects of hippocampal DBS and to investigate the changes induced by different stimulation intensities. Seven rats were stereotactically implanted with a custom-made MRI-compatible DBS-electrode in the right hippocampus. High frequency Poisson distributed stimulation was applied using a block-design paradigm. Data were processed by means of Independent Component Analysis. Clusters were considered significant when p-values were <0.05 after correction for multiple comparisons. Our data indicate that real-time hippocampal DBS evokes a bilateral BOLD response in hippocampal and other mesolimbic structures, depending on the applied stimulation intensity. We conclude that simultaneous DBS and fMRI can be used to detect local and whole-brain responses to circuit activation with different stimulation intensities, making this technique potentially powerful for exploration of cerebral changes in response to DBS for both preclinical and clinical DBS. PMID:26193653

  1. Complexity in Quantum System and Its Application to Brain Function

    E-print Network

    Masanori Ohya

    2004-06-30

    The complexity and the chaos degree can be used to examine the chaotic aspects of not only several nonlinear classical and quantum physical physics but also life sciences. We will construct a model describing the function of brain in the context of Quantum Information Dynamics.

  2. The nicotinic cholinergic system function in the human brain.

    PubMed

    Nees, Frauke

    2015-09-01

    Research on the nicotinic cholinergic system function in the brain was previously mainly derived from animal studies, yet, research in humans is growing. Up to date, findings allow significant advances on the understanding of nicotinic cholinergic effects on human cognition, emotion and behavior using a range of functional brain imaging approaches such as pharmacological functional magnetic resonance imaging or positron emission tomography. Studies provided insights across various mechanistic psychological domains using different tasks as well as at rest in both healthy individuals and patient populations, with so far partly mixed results reporting both enhancements and decrements of neural activity related to the nicotinic cholinergic system. Moreover, studies on the relation between brain structure and the nicotinic cholinergic system add important information in this context. The present review summarizes the current status of human brain imaging studies and presents the findings within a theoretical and clinical perspective as they may be useful not only for an advancement of the understanding of basic nicotinic cholinergic-related mechanisms, but also for the development and integration of psychological and pharmacological treatment approaches. Patterns of functional neuroanatomy and neural circuitry across various cognitive and emotional domains may be used as neuropsychological markers of mental disorders such as addiction, Alzheimer's disease, Parkinson disease or schizophrenia, where nicotinic cholinergic system changes are characteristic. This article is part of the Special Issue entitled 'The Nicotinic Acetylcholine Receptor: From Molecular Biology to Cognition'. PMID:25446570

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

    PubMed

    Martins, D; Tavares, I; Morgado, C

    2014-10-01

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

  4. Functional craniology and brain evolution: from paleontology to biomedicine

    PubMed Central

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

    2014-01-01

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

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

    E-print Network

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

  6. IR Principles for Content-based Indexing and Retrieval of Functional Brain Images

    E-print Network

    IR Principles for Content-based Indexing and Retrieval of Functional Brain Images Bing Bai, Paul(LSI)) to content-based brain image retrieval. Our results show that efficient and accurate retrieval of brain than are methods based on re- taining the full image information. Keywords fMRI, functional brain image

  7. Making the lifetime connection between brain and machine for restoring and enhancing function

    PubMed Central

    Kennedy, Philip; Andreasen, Dinal; Bartels, Jess; Ehirim, Princewill; Mao, Hui; Velliste, Meel; Wichmann, Thomas; Wright, Joe

    2014-01-01

    A reliable neural interface that lasts a lifetime will lead to the development of neural prosthetic devices as well as the possibility that brain function can be enhanced. Our data demonstrate that a reliable neural interface is best achieved when the surrounding neuropil grows into the electrode tip where it is held securely, allowing myelinated axons to be recorded using implanted amplifiers. Stable single and multiunits were recorded from three implanted subjects and classified according to amplitudes and firing rates. In one paralyzed and mute subject implanted for over 5 years with a double electrode in the speech motor cortex, the single units allowed recognition of over half the 39 English language phonemes detected using a variety of decoding methods. These single units were used by the subject in a speech task where vowel phonemes were recognized and fed back to the subject using audio output. Weeks of training resulted in an 80% success rate in producing four vowels in an adaptation of the classic center-out task used in motor control studies. The importance of using single units was shown in a different task using pure tones that the same subject heard and then sung or hummed in his head. Feedback was associated with smoothly coordinated unit firings. The plasticity of the unit firings was demonstrated over several sessions first without, and then with, feedback. These data suggest that units can be reliably recorded over years, that there is an inverse relationship between single unit firing rate and amplitude, that pattern recognition decoding paradigms can allow phoneme recognition, that single units appear more important than multiunits when precision is important, and that units are plastic in their functional relationships. These characteristics of a reliable neural interface are essential for the development of neural prostheses and also for the future enhancement of human brain function. PMID:21867791

  8. The Role of Noise in Brain Function

    NASA Astrophysics Data System (ADS)

    Roy, S.; Llinás, R.

    2012-12-01

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

  9. Neurotrophins and Neuronal Plasticity

    Microsoft Academic Search

    Hans Thoenen

    1995-01-01

    There is increasing evidence that neurotrophins (NTs) are involved in processes of neuronal plasticity besides their well-established actions in regulating the survival, differentiation, and maintenance of functions of specific populations of neurons. Nerve growth factor, brain-derived neurotrophic factor, NT-4\\/5, and corresponding antibodies dramatically modify the development of the visual cortex. Although the neuronal elements involved have not yet been identified,

  10. Molecular mechanisms underlying the regulation and functional plasticity of FOXP3+ regulatory T cells

    Microsoft Academic Search

    Y Gao; F Lin; J Su; Z Gao; Y Li; J Yang; Z Deng; B Liu; A Tsun; B Li

    2012-01-01

    CD4+ CD25+ regulatory T (Treg) cells engage in the maintenance of immunological self-tolerance and homeostasis by limiting aberrant or excessive inflammation. The transcription factor forkhead box P3 (FOXP3) is critical for the development and function of Treg cells. The differentiation of the Treg cell lineage is not terminal, as developmental and functional plasticity occur through the sensing of inflammatory signals

  11. The elastic coherent neutron scattering function S(Q,nu=0) from cyanoadamantane plastic phase

    Microsoft Academic Search

    J. L. Sauvajol; J. Lefebvre; J. P. Amoureux; M. Muller

    1984-01-01

    The elastic diffuse neutron scattering function S(Q, nu =0) from a single crystal of deuterated cyanoadamantane in its plastic phase has been measured throughout the (100) and (110) planes of the reciprocal lattice. By using two models of disorder, the jump model and the expansion of structure factors in symmetry-adapted functions, calculations of the elastic intensity in a self-scattering approximation

  12. Large-scale brain networks in affective and social neuroscience: towards an integrative functional architecture of the brain.

    PubMed

    Barrett, Lisa Feldman; Satpute, Ajay Bhaskar

    2013-06-01

    Understanding how a human brain creates a human mind ultimately depends on mapping psychological categories and concepts to physical measurements of neural response. Although it has long been assumed that emotional, social, and cognitive phenomena are realized in the operations of separate brain regions or brain networks, we demonstrate that it is possible to understand the body of neuroimaging evidence using a framework that relies on domain general, distributed structure-function mappings. We review current research in affective and social neuroscience and argue that the emerging science of large-scale intrinsic brain networks provides a coherent framework for a domain-general functional architecture of the human brain. PMID:23352202

  13. Restoration of Experience-Dependent Plasticity through Enhancement of Glutamatergic Neurotransmission after Developmental Traumatic Brain Injury

    E-print Network

    Sta Maria, Naomi Sulit

    2012-01-01

    In traumatic brain injury (TBI), MRI is being used,MRI has revealed significant hippocampal atrophy in moderate to severe TBITBI. Furthermore, glutamatergic neural activity can now be measured using magnetic resonance imaging (MRI) (

  14. Restoration of function after brain damage using a neural prosthesis

    PubMed Central

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

    2013-01-01

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

  15. Dysfunctional long-term potentiation-like plasticity in schizophrenia revealed by transcranial direct current stimulation

    Microsoft Academic Search

    Alkomiet Hasan; Michael A. Nitsche; Bettina Rein; Thomas Schneider-Axmann; Birgit Guse; Oliver Gruber; Peter Falkai; Thomas Wobrock

    2011-01-01

    Neural and cortical plasticity represent the ability of the brain to reorganize its function in response to a challenge. Plasticity involves changing synaptic activity and connectivity. Long-term-potentiation is one important mechanism underlying these synaptic changes. Disturbed neuronal plasticity is considered to be part of the pathophysiology of schizophrenia and has been linked to the different clinical features of this severe

  16. Neural Plasticity: For Good and Bad

    NASA Astrophysics Data System (ADS)

    Møller, A. R.

    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 ``midcourse correction" during childhood development. If that is not executed in the normal way severe developmental disorders such as autism may results. Normal development of functions and anatomical organization of the brain and the spinal cord depend on appropriate sensory stimulation and motor activations. So-called enriched sensory environments have been shown to be beneficial for cognitive development and enriched acoustic environment may even slow the progression of age-related hearing loss. It is possible that the beneficial effect of physical exercise is achieved through activation of neural plasticity. The beneficial effect of training after trauma to the brain or spinal cord is mainly achieved through shifting functions from damaged brain area to other parts of the central nervous system and adapting these parts to take over the functions that are lost. This is accomplished through activation of neural plasticity. Plastic changes can also be harmful and cause symptoms and signs of disorders such as some forms of chronic pain (central neuropathic pain) and severe tinnitus. We will call such disorders ``plasticity disorders".

  17. Two distinct forms of functional lateralization in the human brain

    PubMed Central

    Gotts, Stephen J.; Jo, Hang Joon; Wallace, Gregory L.; Saad, Ziad S.; Cox, Robert W.; Martin, Alex

    2013-01-01

    The hemispheric lateralization of certain faculties in the human brain has long been held to be beneficial for functioning. However, quantitative relationships between the degree of lateralization in particular brain regions and the level of functioning have yet to be established. Here we demonstrate that two distinct forms of functional lateralization are present in the left vs. the right cerebral hemisphere, with the left hemisphere showing a preference to interact more exclusively with itself, particularly for cortical regions involved in language and fine motor coordination. In contrast, right-hemisphere cortical regions involved in visuospatial and attentional processing interact in a more integrative fashion with both hemispheres. The degree of lateralization present in these distinct systems selectively predicted behavioral measures of verbal and visuospatial ability, providing direct evidence that lateralization is associated with enhanced cognitive ability. PMID:23959883

  18. Functional Brain Network Classification With Compact Representation of SICE Matrices.

    PubMed

    Zhang, Jianjia; Zhou, Luping; Wang, Lei; Li, Wanqing

    2015-06-01

    Recently, a sparse inverse covariance estimation (SICE) technique has been employed to model functional brain connectivity. The inverse covariance matrix (SICE matrix in short) estimated for each subject is used as a representation of brain connectivity to discriminate Alzheimers disease from normal controls. However, we observed that direct use of the SICE matrix does not necessarily give satisfying discrimination, due to its high dimensionality and the scarcity of training subjects. Looking into this problem, we argue that the intrinsic dimensionality of these SICE matrices shall be much lower, considering 1) an SICE matrix resides on a Riemannian manifold of symmetric positive definiteness matrices, and 2) human brains share common patterns of connectivity across subjects. Therefore, we propose to employ manifold-based similarity measures and kernel-based PCA to extract principal connectivity components as a compact representation of brain network. Moreover, to cater for the requirement of both discrimination and interpretation in neuroimage analysis, we develop a novel preimage estimation algorithm to make the obtained connectivity components anatomically interpretable. To verify the efficacy of our method and gain insights into SICE-based brain networks, we conduct extensive experimental study on synthetic data and real rs-fMRI data from the ADNI dataset. Our method outperforms the comparable methods and improves the classification accuracy significantly. PMID:25667346

  19. Sleep restriction impairs blood-brain barrier function.

    PubMed

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

    2014-10-29

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

  20. Recruiting specialized macrophages across the borders to restore brain functions.

    PubMed

    Corraliza, Inés

    2014-01-01

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

  1. Effect of pneumolysin on rat brain ciliary function: comparison of brain slices with cultured ependymal cells.

    PubMed

    Hirst, R A; Rutman, A; Sikand, K; Andrew, P W; Mitchell, T J; O'Callaghan, C

    2000-03-01

    This study compares two models for examining ependymal ciliary function: rat brain slices cut from the fourth ventricle and primary ependymal cells in culture. The cilia from both preparations were very reproducible; each preparation had cilia beating at a constant frequency of between 38 and 44 Hz. With the brain slices, ciliary stasis occurred after 5 d in culture. However, ependymal cells had fully functional cilia for up to 48 d in culture. The pneumococcal toxin, pneumolysin, caused a dose-dependent inhibition of cilia beat frequency within 15 min in both models. There were no significant differences in the mean log 50% inhibitory concentration (pIC50) slice = 0.65 +/- 0.05, equivalent to 4.4 hemolytic units (HU)/mL; cells = 0.57 +/- 0.14, equivalent to 3.7 HU/mL. There were also no significant differences in the mean Hill slope factors for the curves (slice = 1.4 +/- 0.05; cells = 1.6 +/- 0.4). These data demonstrate that both models can be used to examine the acute (15-min) effects of pneumolysin on cilia beat frequency. The main advantage of the primary ependymal culture model is that considerably more cultured ependymal cells (approximately 70%) are available, compared with the number of ependymal cells on the brain slices (approximately 2%), thus reducing the number of animals used. A pure ependymal culture was not achieved (approximately 30% of the cells were not ciliated). The increased survival time of the ependymal cells compared with the brain slices make cultured ependymal cells more useful for examining long-term ciliary function, whereas brain slices may be more useful for examining the interactions between ependymal and other nearby cells. PMID:10709739

  2. Control channels in the brain and their influence on brain executive functions

    NASA Astrophysics Data System (ADS)

    Meng, Qinglei; Choa, Fow-Sen; Hong, Elliot; Wang, Zhiguang; Islam, Mohammad

    2014-05-01

    In a computer network there are distinct data channels and control channels where massive amount of visual information are transported through data channels but the information streams are routed and controlled by intelligent algorithm through "control channels". Recent studies on cognition and consciousness have shown that the brain control channels are closely related to the brainwave beta (14-40 Hz) and alpha (7-13 Hz) oscillations. The high-beta wave is used by brain to synchronize local neural activities and the alpha oscillation is for desynchronization. When two sensory inputs are simultaneously presented to a person, the high-beta is used to select one of the inputs and the alpha is used to deselect the other so that only one input will get the attention. In this work we demonstrated that we can scan a person's brain using binaural beats technique and identify the individual's preferred control channels. The identified control channels can then be used to influence the subject's brain executive functions. In the experiment, an EEG measurement system was used to record and identify a subject's control channels. After these channels were identified, the subject was asked to do Stroop tests. Binaural beats was again used to produce these control-channel frequencies on the subject's brain when we recorded the completion time of each test. We found that the high-beta signal indeed speeded up the subject's executive function performance and reduced the time to complete incongruent tests, while the alpha signal didn't seem to be able to slow down the executive function performance.

  3. Nuclear magnetic resonance imaging and spectroscopy of human brain function.

    PubMed Central

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

    1993-01-01

    The techniques of in vivo magnetic resonance (MR) imaging and spectroscopy have been established over the past two decades. Recent applications of these methods to study human brain function have become a rapidly growing area of research. The development of methods using standard MR contrast agents within the cerebral vasculature has allowed measurements of regional cerebral blood volume (rCBV), which are activity dependent. Subsequent investigations linked the MR relaxation properties of brain tissue to blood oxygenation levels which are also modulated by consumption and blood flow (rCBF). These methods have allowed mapping of brain activity in human visual and motor cortex as well as in areas of the frontal lobe involved in language. The methods have high enough spatial and temporal sensitivity to be used in individual subjects. MR spectroscopy of proton and carbon-13 nuclei has been used to measure rates of glucose transport and metabolism in the human brain. The steady-state measurements of brain glucose concentrations can be used to monitor the glycolytic flux, whereas subsequent glucose metabolism--i.e., the flux into the cerebral glutamate pool--can be used to measure tricarboxylic acid cycle flux. Under visual stimulation the concentration of lactate in the visual cortex has been shown to increase by MR spectroscopy. This increase is compatible with an increase of anaerobic glycolysis under these conditions as earlier proposed from positron emission tomography studies. It is shown how MR spectroscopy can extend this understanding of brain metabolism. Images Fig. 1 Fig. 2 Fig. 3 PMID:8475050

  4. Control of brain development, function, and behavior by the microbiome.

    PubMed

    Sampson, Timothy R; Mazmanian, Sarkis K

    2015-05-13

    Animals share an intimate and life-long partnership with a myriad of resident microbial species, collectively referred to as the microbiota. Symbiotic microbes have been shown to regulate nutrition and metabolism and are critical for the development and function of the immune system. More recently, studies have suggested that gut bacteria can impact neurological outcomes--altering behavior and potentially affecting the onset and/or severity of nervous system disorders. In this review, we highlight emerging evidence that the microbiome extends its influence to the brain via various pathways connecting the gut to the central nervous system. While understanding and appreciation of a gut microbial impact on neurological function is nascent, unraveling gut-microbiome-brain connections holds the promise of transforming the neurosciences and revealing potentially novel etiologies for psychiatric and neurodegenerative disorders. PMID:25974299

  5. Reorganization of functionally connected brain subnetworks in high-functioning autism

    E-print Network

    Glerean, Enrico; Salmi, Juha; Kujala, Rainer; Lahnakoski, Juha; Roine, Ulrika; Nummenmaa, Lauri; Leppämäki, Sami; Wendt, Taina Nieminen-von; Tani, Pekka; Saramäki, Jari; Sams, Mikko; Jääskeläinen, Iiro P

    2015-01-01

    Background: Previous functional connectivity studies have found both hypo- and hyper-connectivity in brains of individuals having autism spectrum disorder (ASD). Here we studied abnormalities in functional brain subnetworks in high-functioning individuals with ASD during free viewing of a movie containing social cues and interactions. Methods: Thirteen subjects with ASD and 13 matched-pair controls watched a 68 minutes movie during functional magnetic resonance imaging. For each subject, we computed Pearson`s correlation between haemodynamic time-courses of each pair of 6-mm isotropic voxels. From the whole-brain functional networks, we derived individual and group-level subnetworks using graph theory. Scaled inclusivity was then calculated between all subject pairs to estimate intersubject similarity of connectivity structure of each subnetwork. Additional 27 individuals with ASD from the ABIDE resting-state database were included to test the reproducibility of the results. Results: Between-group differences...

  6. Harnessing Brain Plasticity through Behavioral Techniques to Produce New Treatments in Neurorehabilitation

    ERIC Educational Resources Information Center

    Taub, Edward

    2004-01-01

    Basic behavioral neuroscience research with monkeys has given rise to an efficacious new approach to the rehabilitation of movement after stroke, cerebral palsy, traumatic brain injury, and other types of neurological injury in humans termed Constraint-Induced Movement therapy or CI therapy. For the upper extremity, the treatment involves…

  7. Role of astroglia in estrogen regulation of synaptic plasticity and brain repair

    Microsoft Academic Search

    Frederick Naftolin; John B. Hutchison; Julie Ann Chowen

    1999-01-01

    Astroglia are targets for estrogen and testosterone and are apparently involved in the action of sex steroids on the brain. Sex hormones induce changes in the expression of glial fibrillary acidic pro- tein, the growth of astrocytic processes, and the degree of apposition of astroglial processes to neuronal mem- branes in the rat hypothalamus. These changes are linked to modifications

  8. Perceptual Shift in Bilingualism: Brain Potentials Reveal Plasticity in Pre-Attentive Colour Perception

    ERIC Educational Resources Information Center

    Athanasopoulos, Panos; Dering, Benjamin; Wiggett, Alison; Kuipers, Jan-Rouke; Thierry, Guillaume

    2010-01-01

    The validity of the linguistic relativity principle continues to stimulate vigorous debate and research. The debate has recently shifted from the behavioural investigation arena to a more biologically grounded field, in which tangible physiological evidence for language effects on perception can be obtained. Using brain potentials in a colour…

  9. Molecular Diversity of Glutamate Receptors and Implications for Brain Function

    Microsoft Academic Search

    Shigetada Nakanishi

    1992-01-01

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

  10. Automated Talairach Atlas labels for functional brain mapping

    Microsoft Academic Search

    Jack L. Lancaster; Marty G. Woldorff; Lawrence M. Parsons; Mario Liotti; Catarina S. Freitas; Lacy Rainey; Peter V. Kochunov; Dan Nickerson; Shawn A. Mikiten; Peter T. Fox

    2000-01-01

    An automated coordinate-based system to retrieve brain labels from the 1988 Talairach Atlas, called the Talairach Daemon (TD), was previously introduced (Lancaster et al., 1997). In the present study, the TD system and its 3-D database of labels for the 1988 Talairach atlas were tested for labeling of functional activation foci. TD system labels were compared with author-designated labels of

  11. A new algorithm for spatiotemporal analysis of brain functional connectivity.

    PubMed

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

    2015-03-15

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

  12. Imaging emotional brain functions: conceptual and methodological issues.

    PubMed

    Peper, Martin

    2006-06-01

    This article reviews the psychophysiological and brain imaging literature on emotional brain function from a methodological point of view. The difficulties in defining, operationalising and measuring emotional activation and, in particular, aversive learning will be considered. Emotion is a response of the organism during an episode of major significance and involves physiological activation, motivational, perceptual, evaluative and learning processes, motor expression, action tendencies and monitoring/subjective feelings. Despite the advances in assessing the physiological correlates of emotional perception and learning processes, a critical appraisal shows that functional neuroimaging approaches encounter methodological difficulties regarding measurement precision (e.g., response scaling and reproducibility) and validity (e.g., response specificity, generalisation to other paradigms, subjects or settings). Since emotional processes are not only the result of localised but also of widely distributed activation, a more representative model of assessment is needed that systematically relates the hierarchy of high- and low-level emotion constructs with the corresponding patterns of activity and functional connectivity of the brain. PMID:16740378

  13. Detecting Brain State Changes via Fiber-Centered Functional Connectivity Analysis

    PubMed Central

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

    2013-01-01

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

  14. IR Principles for Content-based Indexing and Retrieval of Functional Brain Images

    E-print Network

    IR Principles for Content-based Indexing and Retrieval of Functional Brain Images Bing Bai, Paul Indexing(LSI)) to content-based brain image retrieval. Our results show that efficient and accurate of a "library of brain images", which implies not only a repository of brain images, but also efficient search

  15. Location, location: using functional magnetic resonance imaging to pinpoint brain differences

    E-print Network

    Squire, Larry R.

    Location, location: using functional magnetic resonance imaging to pinpoint brain differences is that stimulant- dependent individuals show specific, rather than generic, brain activation differences, i.e. instead of showing more or less brain activation regardless of task, they exhibit process-related brain

  16. Dynamic representations and generative models of brain function.

    PubMed

    Friston, K J; Price, C J

    2001-02-01

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

  17. Imaging Synapse Structure and Function in the Vertebrate Brain Meals are in the Dining Room

    E-print Network

    Eddy, Sean

    : Changes in network structure and function after experience- dependent plasticity and learning - Part 1 and function after experience- dependent plasticity and learning - Part 2 Chair: Wenbiao Gan 11:00 am Aaron W are in the Dining Room Talks are in the Seminar Room Posters are in the Lobby Sunday, March 30th 3:00 pm Check-in 6

  18. The effects of methylphenidate on whole brain intrinsic functional connectivity.

    PubMed

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

    2014-11-01

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

  19. Heritability of human brain functioning as assessed by electroencephalography

    SciTech Connect

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

    1996-03-01

    To study the genetic and environmental contributions to individual differences in CNS functioning, the electroencephalogram (EEG) was measured in 213 twin pairs age 16 years. EEG was measured in 91 MZ and 122 DZ twins. To quantify sex differences in the genetic architecture, EEG was measured in female and male same-sex twins and in opposite-sex twins. EEG was recorded on 14 scalp positions during quiet resting with eyes closed. Spectral powers were calculated for four frequency bands: delta, theta, alpha, and beta. Twin correlations pointed toward high genetic influences for all these powers and scalp locations. Model fitting confirmed these findings; the largest part of the variance of the EEG is explained by additive genetic factors. The averaged heritabilities for the delta, theta, alpha, and beta frequencies was 76%, 89%, 89%, and 86%, respectively. Multivariate analyses suggested that the same genes for EEG alpha rhythm were expressed in different brain areas in the left and right hemisphere. This study shows that brain functioning, as indexed by rhythmic brain-electrical activity, is one of the most heritable characteristics in humans. 44 refs., 5 figs., 4 tabs.

  20. Lateralization of Cognitive Functions in Aphasia after Right Brain Damage

    PubMed Central

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

    2012-01-01

    Purpose The lateralization of cognitive functions in crossed aphasia in dextrals (CAD) has been explored and compared mainly with cases of aphasia with left hemisphere damage. However, comparing the neuropsychological aspects of CAD and aphasia after right brain damage in left-handers (ARL) could potentially provide more insights into the effect of a shift in the laterality of handedness or language on other cognitive organization. Thus, this case study compared two cases of CAD and one case of ARL. Materials and Methods The following neuropsychological measures were obtained from three aphasic patients with right brain damage (two cases of CAD and one case of ARL); language, oral and limb praxis, and nonverbal cognitive functions (visuospatial neglect and visuospatial construction). Results All three patients showed impaired visuoconstructional abilities, whereas each patient showed a different level of performances for oral and limb praxis, and visuospatial neglect. Conclusion Based on the analysis of these three aphasic patients' performances, we highlighted the lateralization of language, handedness, oral and limb praxis, visuospatial neglect and visuospatial constructive ability in aphasic patients with right brain damage. PMID:22476990

  1. A model of the correlation function of leak noise in buried plastic pipes

    NASA Astrophysics Data System (ADS)

    Gao, Y.; Brennan, M. J.; Joseph, P. F.; Muggleton, J. M.; Hunaidi, O.

    2004-10-01

    A common technique for locating leaks in buried water distribution pipes is the use of the cross-correlation on two measured acoustic signals, on either side of a leak. This technique can be problematic for locating leaks in plastic pipes as the acoustic signals in these pipes are generally narrow-band and low frequency. The effectiveness of the cross-correlation technique for detecting leaks in plastic pipes has been investigated experimentally in an earlier study. This paper develops an analytical model to predict the cross-correlation function of leak signals in plastic pipes. The model is based on a theoretical formulation of wave propagation in a fluid-filled pipe in vacuo and the assumption that the leak sound, at source, has a flat spectrum over the bandwidth of interest. The analytical model is used to explain some of the features of correlation measurements made in actual water pipes. Leak noise signals are generally passed through a band-pass filter before calculating the cross-correlation function. The model is used to demonstrate the importance of the cut-off frequency of the high-pass filter and the insensitivity of the correlation to the cut-off frequency of the low-pass filter.

  2. Multiple functions of endocannabinoid signaling in the brain.

    PubMed

    Katona, István; Freund, Tamás F

    2012-01-01

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

  3. BRAIN REGENERATION IN PHYSIOLOGY AND PATHOLOGY: THE IMMUNE SIGNATURE DRIVING THERAPEUTIC PLASTICITY OF NEURAL STEM CELLS

    PubMed Central

    Martino, Gianvito; Pluchino, Stefano; Bonfanti, Luca; Schwartz, Michal

    2013-01-01

    Regenerative processes occurring under physiological (maintenance) and pathological (reparative) conditions are a fundamental part of life and vary greatly among different species, individuals, and tissues. Physiological regeneration occurs naturally as a consequence of normal cell erosion, or as an inevitable outcome of any biological process aiming at the restoration of homeostasis. Reparative regeneration occurs as a consequence of tissue damage. Although the central nervous system (CNS) has been considered for years as a “perennial” tissue, it has recently become clear that both physiological and reparative regeneration occur also within the CNS to sustain tissue homeostasis and repair. Proliferation and differentiation of neural stem/progenitor cells (NPCs) residing within the healthy CNS, or surviving injury, are considered crucial in sustaining these processes. Thus a large number of experimental stem cell-based transplantation systems for CNS repair have recently been established. The results suggest that transplanted NPCs promote tissue repair not only via cell replacement but also through their local contribution to changes in the diseased tissue milieu. This review focuses on the remarkable plasticity of endogenous and exogenous (transplanted) NPCs in promoting repair. Special attention will be given to the cross-talk existing between NPCs and CNS-resident microglia as well as CNS-infiltrating immune cells from the circulation, as a crucial event sustaining NPC-mediated neuroprotection. Finally, we will propose the concept of the context-dependent potency of transplanted NPCs (therapeutic plasticity) to exert multiple therapeutic actions, such as cell replacement, neurotrophic support, and immunomodulation, in CNS repair. PMID:22013212

  4. Sequential [(18)F]FDG µPET whole-brain imaging of central vestibular compensation: a model of deafferentation-induced brain plasticity.

    PubMed

    Zwergal, Andreas; Schlichtiger, Julia; Xiong, Guoming; Beck, Roswitha; Günther, Lisa; Schniepp, Roman; Schöberl, Florian; Jahn, Klaus; Brandt, Thomas; Strupp, Michael; Bartenstein, Peter; Dieterich, Marianne; Dutia, Mayank B; la Fougère, Christian

    2014-10-01

    Unilateral inner ear damage is followed by a rapid behavioural recovery due to central vestibular compensation. In this study, we utilized serial [(18)F]Fluoro-deoxyglucose ([(18)F]FDG)-µPET imaging in the rat to visualize changes in brain glucose metabolism during behavioural recovery after surgical and chemical unilateral labyrinthectomy, to determine the extent and time-course of the involvement of different brain regions in vestibular compensation and test previously described hypotheses of underlying mechanisms. Systematic patterns of relative changes of glucose metabolism (rCGM) were observed during vestibular compensation. A significant asymmetry of rCGM appeared in the vestibular nuclei, vestibulocerebellum, thalamus, multisensory vestibular cortex, hippocampus and amygdala in the acute phase of vestibular imbalance (4 h). This was followed by early vestibular compensation over 1-2 days where rCGM re-balanced between the vestibular nuclei, thalami and temporoparietal cortices and bilateral rCGM increase appeared in the hippocampus and amygdala. Subsequently over 2-7 days, rCGM increased in the ipsilesional spinal trigeminal nucleus and later (7-9 days) rCGM increased in the vestibulocerebellum bilaterally and the hypothalamus and persisted in the hippocampus. These systematic dynamic rCGM patterns during vestibular compensation, were confirmed in a second rat model of chemical unilateral labyrinthectomy by serial [(18)F]FDG-µPET. These findings show that deafferentation-induced plasticity after unilateral labyrinthectomy involves early mechanisms of re-balancing predominantly in the brainstem vestibular nuclei but also in thalamo-cortical and limbic areas, and indicate the contribution of spinocerebellar sensory inputs and vestibulocerebellar adaptation at the later stages of behavioural recovery. PMID:25269833

  5. Exercise facilitates the action of dietary DHA on functional recovery after brain trauma

    PubMed Central

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

    2013-01-01

    The abilities of docosahexaenoic acid (DHA) and exercise to counteract cognitive decay after TBI is getting increasing recognition; however, the possibility that these actions can be complementary remains just as an intriguing possibility. Here we have examined the likelihood that the combination of diet and exercise has the added potential to facilitate functional recovery following TBI. Rats received mild fluid percussion injury (mFPI) or sham injury and then were maintained on a diet high in DHA (1.2% DHA) with or without voluntary exercise for 12 days. We found that FPI reduced DHA content in the brain, which was accompanied by increased levels of lipid peroxidation assessed using 4-HHE. FPI reduced the enzymes Acox1 and 17 -HSD4, and the calcium-independent phospholipases A2 (iPLA2), which are involved in metabolism of membrane phospholipids. FPI reduced levels of syntaxin-3 (STX-3), involved in the action of membrane DHA on synaptic membrane expansion, and also reduced BDNF signaling through its TrkB receptor. These effects of FPI were optimally counteracted by the combination of DHA and exercise. Our results support the possibility that the complementary action of exercise is exerted on restoring membrane homeostasis after TBI, which is necessary for supporting synaptic plasticity and cognition. It is our contention that strategies that take advantage of the combined applications of diet and exercise may have additional effects to the injured brain. PMID:23811071

  6. Irradiation of rat brain reduces P-glycoprotein expression and function

    Microsoft Academic Search

    J. Bart; W. B. Nagengast; R. P. Coppes; T. D. Wegman; H J M Groen; W. Vaalburg; E. G. F. de Vries; N. H. Hendrikse; EGE de Vries

    2007-01-01

    The blood–brain barrier (BBB) hampers delivery of several drugs including chemotherapeutics to the brain. The drug efflux pump P-glycoprotein (P-gp), expressed on brain capillary endothelial cells, is part of the BBB. P-gp expression on capillary endothelium decreases 5 days after brain irradiation, which may reduce P-gp function and increase brain levels of P-gp substrates. To elucidate whether radiation therapy reduces

  7. Imaging structural and functional brain networks in temporal lobe epilepsy

    PubMed Central

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

    2013-01-01

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

  8. Sleep-disordered breathing: effects on brain structure and function

    PubMed Central

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

    2013-01-01

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

  9. Functional interactions between intrinsic brain activity and behavior.

    PubMed

    Sadaghiani, Sepideh; Kleinschmidt, Andreas

    2013-10-15

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

  10. Hubs of brain functional networks are radically reorganized in comatose patients

    E-print Network

    Boyer, Edmond

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

  11. Multivariate examination of brain abnormality using both structural and functional MRI

    Microsoft Academic Search

    Yong Fan; Hengyi Rao; Hallam Hurt; Joan Giannetta; Marc Korczykowski; David Shera; Brian B. Avants; James C. Gee; Jiongjiong Wang; Dinggang Shen

    2007-01-01

    A multivariate classification approach has been presented to examine the brain abnormalities, i.e., due to prenatal cocaine exposure, using both structural and functional brain images. First, a regional statistical feature extraction scheme was adopted to capture discriminative features from voxel-wise morphometric and functional representations of brain images, in order to reduce the dimensionality of the features used for classification, as

  12. Iron in Brain Function and Dysfunction with Emphasis on Parkinson’s Disease

    Microsoft Academic Search

    M. B. H. Youdim; D. Ben-Shachar; P. Riederer

    1991-01-01

    Metals such as lead, zinc, copper, aluminum and manganese have been implicated in neuropsychiatric disorders. However, until fairly recently the role of iron in brain function was rather obscure, because little attention was paid to its metabolism in the brain. It is now apparent that maintenance of brain iron homoeostasis is important for the normal functioning of his organ. Most

  13. Individual differences in general intelligence correlate with brain function during nonreasoning tasks

    Microsoft Academic Search

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

    2003-01-01

    Brain imaging can help identify the functional neuroanatomy of general intelligence (i.e., “g”) and indicate how brain areas salient to g relate to information processing. An important question is whether individual differences in g among subjects are related to brain function even when nonreasoning tasks are studied. If so, this would imply that individuals with high g scores may process

  14. Adrenomedullin Improves the Blood–Brain Barrier Function Through the Expression of Claudin-5

    Microsoft Academic Search

    Masaru Honda; Shinsuke Nakagawa; Kentaro Hayashi; Naoki Kitagawa; Keisuke Tsutsumi; Izumi Nagata; Masami Niwa

    2006-01-01

    Summary  1. Aims: Brain vascular endothelial cells secret Adrenomedullin (AM) has multifunctional biological properties. AM affects cerebral blood flow and blood–brain barrier (BBB) function. We studied the role of AM on the permeability and tight junction proteins of brain microvascular endothelial cells (BMEC).2. Methods: BMEC were isolated from rats and a BBB in vitro model was generated. The barrier functions were

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

    PubMed Central

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

    2009-01-01

    We investigated interactions between HIV and aging on brain function demands using functional magnetic resonance imaging (fMRI). A multiple regression model studied the association and interaction between fMRI measures, HIV serostatus, and age for 26 HIV infected (HIV+) and 25 seronegative (HIV?) subjects. While HIV serostatus and age independently affected fMRI measures, no interaction occurred. Functional brain demands in HIV+ subjects were equivalent to ~15–20 year older HIV? subjects. Frailty parallels between HIV and aging could result from continued immunological challenges depleting resources and triggering increased metabolic demands. fMRI could be a non-invasive biomarker to assess HIV in the brain. PMID:20047503

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

    PubMed Central

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

    2011-01-01

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

  17. Neural plasticity lessons from disorders of consciousness.

    PubMed

    Demertzi, Athena; Schnakers, Caroline; Soddu, Andrea; Bruno, Marie-Aurélie; Gosseries, Olivia; Vanhaudenhuyse, Audrey; Laureys, Steven

    2010-01-01

    Communication and intentional behavior are supported by the brain's integrity at a structural and a functional level. When widespread loss of cerebral connectivity is brought about as a result of a severe brain injury, in many cases patients are not capable of conscious interactive behavior and are said to suffer from disorders of consciousness (e.g., coma, vegetative state/unresponsive wakefulness syndrome, minimally conscious states). This lesion paradigm has offered not only clinical insights, as how to improve diagnosis, prognosis, and treatment, but also put forward scientific opportunities to study the brain's plastic abilities. We here review interventional and observational studies performed in severely brain-injured patients with regards to recovery of consciousness. The study of the recovered conscious brain (spontaneous and/or after surgical or pharmacologic interventions), suggests a link between some specific brain areas and the capacity of the brain to sustain conscious experience, challenging at the same time the notion of fixed temporal boundaries in rehabilitative processes. Altered functional connectivity, cerebral structural reorganization as well as behavioral amelioration after invasive treatments will be discussed as the main indices for plasticity in these challenging patients. The study of patients with chronic disorders of consciousness may, thus, provide further insights not only at a clinical level (i.e., medical management and rehabilitation) but also from a scientific-theoretical perspective (i.e., the brain's plastic abilities and the pursuit of the neural correlate of consciousness). PMID:21833298

  18. Neuroendocrinology of song behavior and avian brain plasticity: multiple sites of action of sex steroid hormones.

    PubMed

    Ball, Gregory F; Riters, Lauren V; Balthazart, Jacques

    2002-04-01

    Seasonal changes in the brain of songbirds are one of the most dramatic examples of naturally occurring neuroplasticity that have been described in any vertebrate species. In males of temperate-zone songbird species, the volumes of several telencephalic nuclei that control song behavior are significantly larger in the spring than in the fall. These increases in volume are correlated with high rates of singing and high concentrations of testosterone in the plasma. Several song nuclei express either androgen receptors or estrogen receptors, therefore it is possible that testosterone acting via estrogenic or androgenic metabolites regulates song behavior by seasonally modulating the morphology of these song control nuclei. However, the causal links among these variables have not been established. Dissociations among high concentrations of testosterone, enlarged song nuclei, and high rates of singing behavior have been observed. Singing behavior itself can promote cellular changes associated with increases in the volume of the song control nuclei. Also, testosterone may stimulate song behavior by acting in brain regions outside of the song control system such as in the preoptic area or in catecholamine cell groups in the brainstem. Thus testosterone effects on neuroplasticity in the song system may be indirect in that behavioral activity stimulated by testosterone acting in sites that promote male sexual behavior could in turn promote morphological changes in the song system. PMID:11950243

  19. Sex differences in synaptic plasticity in stress-responsive brain regions following chronic variable stress

    PubMed Central

    Carvalho-Netto, Eduardo F.; Myers, Brent; Jones, Kenneth; Solomon, Matia B.; Herman, James P.

    2015-01-01

    Increased stress responsiveness is implicated in the etiology of mood and anxiety disorders, including depression and post-traumatic stress disorder. Additionally, stress-related affective disorders have a higher incidence in women than men. Chronic stress in rodents produces numerous neuromorphological changes in a variety of limbic brain regions. Here, we examined the sex-dependent differences in presynaptic innervation of the paraventricular nucleus of the hypothalamus (PVN), prefrontal cortex (PFC), bed nucleus of the stria terminalis (BST), and amygdala in response to chronic variable stress (CVS). Following 14 days of CVS, the presynaptic protein synaptophysin was assessed in male and female rats. Our results demonstrate that synaptophysin staining density was higher in females than males in all brain areas evaluated, indicating sex differences in the organization of presynaptic innervation. After CVS, the PVN, principal nucleus of the BST (BSTpr), and basolateral nucleus of the amygdala (BLA) displayed significantly reduced synaptophysin density in females but not males. Furthermore, males showed an increase in synaptophysin in the PVN after CVS, suggesting a sex difference in the modulation of presynaptic inputs to the PVN following chronic stress. Overall, these data suggest marked sex differences in PVN, BSTpr, and BLA presynaptic innervation as a consequence of chronic stress, which may be associated with differential stress responsivity and perhaps susceptibility to pathologies in males and females. PMID:21315096

  20. Natural History of Brain Function, Quality of Life, and Seizure Control in Patients With Brain Tumor Who Have Undergone Surgery | Division of Cancer Prevention

    Cancer.gov

    This trial studies the natural history of brain function, quality of life, and seizure control in patients with brain tumor who have undergone surgery. Learning about brain function, quality of life, and seizure control in patients with brain tumor who have undergone surgery may help doctors learn more about the disease and find better methods of treatment and on-going care.

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

    EPA Science Inventory

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

  2. The illiterate brain. Learning to read and write during childhood influences the functional organization of the adult brain

    Microsoft Academic Search

    A. Castro-Caldas; K. M. Petersson; A. Reis; S. Stone-Elander; M. Ingvar

    1998-01-01

    Summary Learning a specific skill during childhood may partly determine the functional organization of the adult brain. This hypothesis led us to study oral language processing in illiterate subjects who, for social reasons, had never entered school and had no knowledge of reading or writing. In a brain activation study using PET and statistical parametric mapping, we compared word and

  3. Cortical cross-modal plasticity following deafness measured using functional near-infrared spectroscopy.

    PubMed

    Dewey, Rebecca S; Hartley, Douglas E H

    2015-07-01

    Evidence from functional neuroimaging studies suggests that the auditory cortex can become more responsive to visual and somatosensory stimulation following deafness, and that this occurs predominately in the right hemisphere. Extensive cross-modal plasticity in prospective cochlear implant recipients is correlated with poor speech outcomes following implantation, highlighting the potential impact of central auditory plasticity on subsequent aural rehabilitation. Conversely, the effects of hearing restoration with a cochlear implant on cortical plasticity are less well understood, since the use of most neuroimaging techniques in CI recipients is either unsafe or problematic due to the electromagnetic artefacts generated by CI stimulation. Additionally, techniques such as functional magnetic resonance imaging (fMRI) are confounded by acoustic noise produced by the scanner that will be perceived more by hearing than by deaf individuals. Subsequently it is conceivable that auditory responses to acoustic noise produced by the MR scanner may mask auditory cortical responses to non-auditory stimulation, and render inter-group comparisons less significant. Uniquely, functional near-infrared spectroscopy (fNIRS) is a silent neuroimaging technique that is non-invasive and completely unaffected by the presence of a CI. Here, we used fNIRS to study temporal-lobe responses to auditory, visual and somatosensory stimuli in thirty profoundly-deaf participants and thirty normally-hearing controls. Compared with silence, acoustic noise stimuli elicited a significant group fNIRS response in the temporal region of normally-hearing individuals, which was not seen in profoundly-deaf participants. Visual motion elicited a larger group response within the right temporal lobe of profoundly-deaf participants, compared with normally-hearing controls. However, bilateral temporal lobe fNIRS activation to somatosensory stimulation was comparable in both groups. Using fNIRS these results confirm that auditory deprivation is associated with cross-modal plasticity of visual inputs to auditory cortex. Although we found no evidence for plasticity of somatosensory inputs, it is possible that our recordings may have included activation of somatosensory cortex that masked any group differences in auditory cortical responses due to the limited spatial resolution associated with fNIRS. PMID:25819496

  4. New insights into brain BDNF function in normal aging and Alzheimer disease

    Microsoft Academic Search

    Lucia Tapia-Arancibia; Esteban Aliaga; Michelle Silhol; Sandor Arancibia

    2008-01-01

    The decline observed during aging involves multiple factors that influence several systems. It is the case for learning and memory processes which are severely reduced with aging. It is admitted that these cognitive effects result from impaired neuronal plasticity, which is altered in normal aging but mainly in Alzheimer disease. Neurotrophins and their receptors, notably BDNF, are expressed in brain

  5. Inhibition of steroid receptor coactivator-1 blocks estrogen and androgen action on male sex behavior and associated brain plasticity.

    PubMed

    Charlier, Thierry D; Ball, Gregory F; Balthazart, Jacques

    2005-01-26

    Studies of eukaryotic gene expression demonstrate the importance of nuclear steroid receptor coactivators in mediating efficient gene transcription. However, little is known about the physiological role of these coactivators in vivo. In Japanese quail, the steroid receptor coactivator-1 (SRC-1) is broadly expressed in steroid-sensitive brain areas that control the expression of male copulatory behavior, and we investigated the role of this coactivator by antisense technology. Daily intracerebroventricular injections of locked nucleic acid (LNA) antisense (AS) oligonucleotides targeting SRC-1 significantly reduced the expression of androgen- and estrogen-dependent male-typical sexual behaviors compared with control animals that received the vehicle alone or scrambled oligonucleotides. Sexual behavior was restored and even enhanced within 48 h after interruption of LNA injections. Western blot analysis confirmed the decrease of SRC-1 expression in AS animals and suggested an overexpression 48 h after the end of injections. The effects of SRC-1 knock-down on behavior correlated with a reduction in volume of the preoptic medial nucleus (POM) when its borders were defined by Nissl staining or by aromatase immunohistochemistry. The amount of aromatase-immunoreactive material in POM was also reduced in the AS compared with the control group. Previous work on SRC-1 knock-out mice raised questions about the importance of this specific coactivator in the regulation of reproductive behavior and development of sexually dimorphic structures in the CNS. Together, the present findings indicate that SRC-1 modulates steroid-dependent gene transcription and behavior and highlight the rapid time course of steroid-induced brain plasticity in adult quail. PMID:15673671

  6. Operating Characteristics of Executive Functioning Tests Following Traumatic Brain Injury

    PubMed Central

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

    2010-01-01

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

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

    PubMed Central

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

    2011-01-01

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

  8. Behavioral relevance of the dynamics of the functional brain connectome.

    PubMed

    Jia, Hao; Hu, Xiaoping; Deshpande, Gopikrishna

    2014-11-01

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

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

    PubMed

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

    2006-02-01

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

  10. Differential patterns of functional and structural plasticity within and between inferior frontal gyri support training-induced improvements in inhibitory control proficiency.

    PubMed

    Chavan, Camille F; Mouthon, Michael; Draganski, Bogdan; van der Zwaag, Wietske; Spierer, Lucas

    2015-07-01

    Ample evidence indicates that inhibitory control (IC), a key executive component referring to the ability to suppress cognitive or motor processes, relies on a right-lateralized fronto-basal brain network. However, whether and how IC can be improved with training and the underlying neuroplastic mechanisms remains largely unresolved. We used functional and structural magnetic resonance imaging to measure the effects of 2 weeks of training with a Go/NoGo task specifically designed to improve frontal top-down IC mechanisms. The training-induced behavioral improvements were accompanied by a decrease in neural activity to inhibition trials within the right pars opercularis and triangularis, and in the left pars orbitalis of the inferior frontal gyri. Analyses of changes in brain anatomy induced by the IC training revealed increases in grey matter volume in the right pars orbitalis and modulations of white matter microstructure in the right pars triangularis. The task-specificity of the effects of training was confirmed by an absence of change in neural activity to a control working memory task. Our combined anatomical and functional findings indicate that differential patterns of functional and structural plasticity between and within inferior frontal gyri enhanced the speed of top-down inhibition processes and in turn IC proficiency. The results suggest that training-based interventions might help overcoming the anatomic and functional deficits of inferior frontal gyri manifesting in inhibition-related clinical conditions. More generally, we demonstrate how multimodal neuroimaging investigations of training-induced neuroplasticity enable revealing novel anatomo-functional dissociations within frontal executive brain networks. Hum Brain Mapp 36:2527-2543, 2015. © 2015 Wiley Periodicals, Inc. PMID:25801718

  11. Anticorrelated Resting-state Functional Connectivity in Awake Rat Brain

    PubMed Central

    Liang, Zhifeng; King, Jean; Zhang, Nanyin

    2011-01-01

    Resting-state functional connectivity (RSFC) measured by functional magnetic resonance imaging has played an essential role in understanding neural circuitry and brain diseases. The vast majority of RSFC studies have been focused on positive RSFC, whereas our understanding about its conceptual counterpart—negative RSFC (i.e. anticorrelation)—remains elusive. To date, anticorrelated RSFC has yet been observed without the commonly used preprocessing step of global signal correction. However, this step can induce artifactual anticorrelation (Murphy et al., 2009), making it difficult to determine whether the observed anticorrelation in humans is a processing artifact (Fox et al., 2005). In this report we demonstrated robust anticorrelated RSFC in a well characterized frontolimbic circuit between the infralimbic cortex (IL) and amygdala in the awake rat. This anticorrelation was anatomically specific, highly reproducible and independent of preprocessing methods. Interestingly, this anticorrelated relationship was absent in anesthetized rats even with global signal regression, further supporting its functional significance. Establishing negative RSFC independent of data preprocessing methods will significantly enhance the applicability of RSFC in better understanding neural circuitries and brain networks. In addition, combining the neurobiological data of the IL-amygdala circuit in rodents, the finding of the present study will enable further investigation of the neurobiological basis underlying anticorrelation. PMID:21864689

  12. Brain functional connectivity and the pathophysiology of schizophrenia.

    PubMed

    Angelopoulos, E

    2014-01-01

    In the last decade there is extensive evidence to suggest that cognitive functions depending on coordination of distributed neuronal responses are associated with synchronized oscillatory activity in various frequency ranges suggesting a functional mechanism of neural oscillations in cortical networks. In addition to their role in normal brain functioning, there is increasing evidence that altered oscillatory activity may be associated with certain neuropsychiatric disorders, such as schizophrenia. Consequently, disturbances in neural synchronization may represent the functional relationship of disordered connectivity of cortical networks underlying the characteristic fragmentation of mind and behavior in schizophrenia. In recent studies the synchronization of oscillatory activity in the experience of characteristic symptoms such as auditory verbal hallucinations and thought blocks have been studied in patients with schizophrenia. Studies involving analysis of EEG activity obtained from individuals in resting state (in cage Faraday, isolated from external influences and with eyes closed). In patients with schizophrenia and persistent auditory verbal hallucinations (AVHs) observed a temporary increase in the synchronization phase of ? and high ? oscillations of the electroencephalogram (EEG) compared with those of healthy controls and patients without AVHs . This functional hyper-connection manifested in time windows corresponding to experience AVHs, as noted by the patients during the recording of EEG and observed in speech related cortical areas. In another study an interaction of theta and gamma oscillations engages in the production and experience of AVHs. The results showed increased phase coupling between theta and gamma EEG rhythms in the left temporal cortex during AVHs experiences. A more recent study, approaches the thought blocking experience in terms of functional brain connectivity. Thought blocks (TBs) are characterized by regular interruptions of the flow of thought. Outward signs are abrupt and repeated interruptions in the flow of conversation or actions while subjective experience is that of a total and uncontrollable emptying of the mind. In the very limited bibliography regarding TB, the phenomenon is thought to be conceptualized as a disturbance of consciousness that can be attributed to stoppages of continuous information processing due to an increase in the volume of information to be processed. In an attempt to investigate potential expression of the phenomenon on the functional properties of electroencephalographic (EEG) activity, an EEG study was contacted in schizophrenic patients with persisting auditory verbal hallucinations (AVHs) who additionally exhibited TBs. Phase synchronization analyses performed on EEG segments during the experience of TBs showed that synchrony values exhibited a long-range common mode of coupling (grouped behavior) among the left temporal area and the remaining central and frontal brain areas. These common synchrony-fluctuation schemes were observed for 0.5 to 2 s and were detected in a 4-s window following the estimated initiation of the phenomenon. The observation was frequency specific and detected in the broad alpha band region (6-12 Hz). The introduction of synchrony entropy (SE) analysis applied on the cumulative synchrony distribution showed that TB states were characterized by an explicit preference of the system to be functioned at low values of synchrony, while the synchrony values are broadly distributed during the recovery state. The results indicate that during TB states, the phase locking of several brain areas were converged uniformly in a narrow band of low synchrony values and in a distinct time window, impeding thus the ability of the system to recruit and to process information during this time window. The results of this study seem to have greater importance on neuronal correlation of consciousness. The brain is a highly distributed system in which numerous operations are executed in parallel and that lacks a single coordinating center. This rais

  13. Crossed-Brain Representation of Verbal and Nonverbal Functions

    PubMed Central

    Matute, Esmeralda; Ardila, Alfredo; Rosselli, Monica; Molina Del Rio, Jahaziel; López Elizalde, Ramiro; López, Manuel; Ontiveros, Angel

    2015-01-01

    A 74-year-old, left-handed man presented with a rapidly evolving loss of strength in his right leg associated with difficulty in walking. MR images disclosed an extensive left hemisphere tumor. A neuropsychological examination revealed that language was broadly normal but that the patient presented with severe nonlinguistic abnormalities, including hemineglect (both somatic and spatial), constructional defects, and general spatial disturbances; symptoms were usually associated with right hemisphere pathologies. No ideomotor apraxia was found. The implications of crossed-brain representations of verbal and nonverbal functions are analyzed. PMID:25802778

  14. Alcohol: Effects on Neurobehavioral Functions and the Brain

    PubMed Central

    Oscar-Berman, Marlene; Marinkovi?, Ksenija

    2014-01-01

    Alcoholism results from an interplay between genetic and environmental factors, and is linked to brain defects and associated cognitive, emotional, and behavioral impairments. A confluence of findings from neuroimaging, physiological, neuropathological, and neuropsychological studies of alcoholics indicate that the frontal lobes, limbic system, and cerebellum are particularly vulnerable to damage and dysfunction. An integrative approach employing a variety of neuroscientific technologies is essential for recognizing the interconnectivity of the different functional systems affected by alcoholism. In that way, relevant experimental techniques can be applied to assist in determining the degree to which abstinence and treatment contribute to the reversal of atrophy and dysfunction. PMID:17874302

  15. Age, sex, and dominance-related mushroom body plasticity in the paperwaspMischocyttarus mastigophorus

    Microsoft Academic Search

    Yamile Molina; Sean O'Donnell

    2008-01-01

    Social Hymenoptera are important models for analyzing functional brain plasticity. These insects provide the opportunity to learn how individuals' social roles are related to flexible investment in different brain regions. We assessed how age, sex, and individual behavior influence brain development in a primitively eusocial paper wasp, Mischocyttarus mastigophorus. Previous research in other species has demonstrated experience-dependent changes in central

  16. Functional development in the infant brain for auditory pitch processing.

    PubMed

    Homae, Fumitaka; Watanabe, Hama; Nakano, Tamami; Taga, Gentaro

    2012-03-01

    Understanding how the developing brain processes auditory information is a critical step toward the clarification of infants' perception of speech and music. We have reported that the infant brain perceives pitch information in speech sounds. Here, we used multichannel near-infrared spectroscopy to examine whether the infant brain is sensitive to information of pitch changes in auditory sequences. Three types of auditory sequences with distinct temporal structures of pitch changes were presented to 3- and 6-month-old infants: a long condition of 12 successive tones constructing a chromatic scale (600 ms), a short condition of four successive tones constructing a chromatic scale (200 ms), and a random condition of random tone sequences (50 ms per tone). The difference among the conditions was only in the sequential order of the tones, which causes pitch changes between the successive tones. We found that the bilateral temporal regions of both ages of infants showed significant activation under the three conditions. The stimulus-dependent activation was observed in the right temporoparietal region of the both infant groups; the 3- and 6-month-old infants showed the most prominent activation under the random and short conditions, respectively. Our findings indicate that the infant brain, which shows functional differentiation and lateralization in auditory-related areas, is capable of responding to more than single tones of pitch information. These results suggest that the right temporoparietal region of the infants increases sensitivity to auditory sequences, which have temporal structures similar to those of syllables in speech sounds, in the course of development. PMID:21488136

  17. EMOTION REGULATION AND BRAIN PLASTICITY: EXPRESSIVE SUPPRESSION USE PREDICTS ANTERIOR INSULA VOLUME

    PubMed Central

    Giuliani, Nicole R.; Drabant, Emily M.; Bhatnagar, Roshni; Gross, James J.

    2011-01-01

    Expressive suppression is an emotion regulation strategy that requires interoceptive and emotional awareness. These processes both recruit the anterior insula. It is not known, however, whether increased use of expressive suppression is associated with increased anterior insula volume. In the present study, high-resolution anatomical MRI images were used to calculate insula volumes in a set of 50 healthy female subjects (mean 21.9 years) using both region of interest (ROI) and voxel-based morphometry (VBM) approaches. Participants also completed trait measures of expressive suppression usage, cognitive reappraisal usage, and negative emotional reactivity (the latter two served as control measures). As predicted, both ROI and VBM methods found that expressive suppression usage, but not negative affect and cognitive reappraisal, was positively related to anterior insula volume. These findings are consistent with the idea that trait patterns of emotion processing are related to brain structure. PMID:21704173

  18. Focal Gray Matter Plasticity as a Function of Long Duration Head-down Tilt Bed Rest

    NASA Technical Reports Server (NTRS)

    Koppelmans, V.; DeDios, Y. E.; Wood, S. J.; Reuter-Lorenz, P. A.; Kofman, I.; Bloomberg, J. J.; Mulavara, A. P.; Koppelmans, V.

    2014-01-01

    Long duration spaceflight (i.e., > or = 22 days) has been associated with changes in sensorimotor systems, resulting in difficulties that astronauts experience with posture control, locomotion, and manual control. The microgravity environment is an important causal factor for spaceflight induced sensorimotor changes. Whether these sensorimotor changes may be related to structural and functional brain changes is yet unknown. However, experimental studies revealed changes in the gray matter (GM) of the brain after simulated microgravity. Thus, it is possible that spaceflight may affect brain structure and thereby cognitive functioning and motor behavior. Long duration head-down tilt bed rest has been suggested as an exclusionary analog to study microgravity effects on the sensorimotor system. Bed rest mimics microgravity in body unloading and bodily fluid shifts. In consideration of the health and performance of crewmembers both in- and post-flight, we are conducting a prospective longitudinal 70-day bed rest study as an analog to investigate the effects of microgravity on the brain. VBM analysis revealed a progressive decrease from pre- to in- bed rest in GM volume in bilateral areas including the frontal medial cortex, the insular cortex and the caudate. Over the same time period, there was a progressive increase in GM volume in the cerebellum, occipital-, and parietal cortex, including the precuneus. The majority of these changes did not fully recover during the post-bed rest period. Analysis of lobular GM volumes obtained with BRAINS showed significantly increased volume from pre-bed rest to in-bed rest in GM of the parietal lobe and the third ventricle. Temporal GM volume at 70 days in bed rest was smaller than that at the first pre-bed rest measurement. Trend analysis showed significant positive linear and negative quadratic relationships between parietal GM and time, a positive linear relationship between third ventricle volume and time, and a negative linear relationship between cerebellar GM volume and time. FM performance improved from pre-bed rest session 1 to session 2. From the second pre-bed rest measure to the last-day-in-bed rest, there was a significant decrease in performance that only partially recovered post-bed rest. No significant association was observed between changes in brain volume and changes in functional mobility. Extended bed rest, which is an analog for microgravity, can result in local volumetric GM increase and decrease and adversely affect functional mobility. These changes in brain structure and performance were not related in this sample. Whether the effects of bed rest dissipate at longer times post-bed rest, and if they are associated with behavior are important questions that warrant further research including more subjects and longer follow-up times.

  19. High-resolution functional magnetic resonance imaging of the animal brain

    Microsoft Academic Search

    Seong-Gi Kim; Kamil Ugurbil

    2003-01-01

    To fully understand brain function, one must look beyond the level of a single neuron. By elucidating the spatial properties of the columnar and laminar functional architectures, information regarding the neural processing in the brain can be gained. To map these fine functional structures noninvasively and repeatedly, functional magnetic resonance imaging (fMRI) can be employed. In this article the basic

  20. OBESITY/HYPERLEPTINEMIC PHENOTYPE IMPAIRS STRUCTURAL AND FUNCTIONAL PLASTICITY IN THE RAT HIPPOCAMPUS

    PubMed Central

    Grillo, Claudia A.; Piroli, Gerardo G.; Junor, Lorain; Wilson, Steven P.; Mott, David D.; Wilson, Marlene A.; Reagan, Lawrence P.

    2011-01-01

    Epidemiological studies estimate that greater than 60% of the adult US population may be categorized as either overweight or obese and there is a growing appreciation that the complications of obesity extend to the central nervous system (CNS). While the vast majority of these studies have focused upon the hypothalamus, more recent studies suggest that the complications of obesity may also affect the structural and functional integrity of the hippocampus. A potential contributor to obesity-related CNS abnormalities is the adipocyte-derived hormone leptin. In this regard, decreases in CNS leptin activity may contribute to deficits in hippocampal synaptic plasticity and suggest that leptin resistance, a well described phenomenon in the hypothalamus, may also be observed in the hippocampus. Unfortunately, the myriad of metabolic and endocrine abnormalities in diabetes/obesity phenotypes makes it challenging to assess the role of leptin in hippocampal neuroplasticity deficits associated with obesity models. To address this question, we examined hippocampal morphological and behavioral plasticity following lentivirus-mediated downregulation of hypothalamic insulin receptors (hypo-IRAS). Hypo-IRAS rats exhibit increases in body weight, adiposity, plasma leptin and triglyceride levels. As such, hypo-IRAS rats develop a phenotype that is consistent with features of the metabolic syndrome. In addition, hippocampal morphological plasticity and performance of hippocampal-dependent tasks are adversely affected in hypo-IRAS rats. Leptin-mediated signaling is also decreased in hypo-IRAS rats. We will discuss these findings in the context of how hyperleptinemia and hypertriglyceridemia may represent mechanistic mediators of the neurological consequences of impaired hippocampal synaptic plasticity in obesity. PMID:21354191

  1. WLPVG approach to the analysis of EEG-based functional brain network under manual acupuncture.

    PubMed

    Pei, Xin; Wang, Jiang; Deng, Bin; Wei, Xile; Yu, Haitao

    2014-10-01

    Functional brain network, one of the main methods for brain functional studies, can provide the connectivity information among brain regions. In this research, EEG-based functional brain network is built and analyzed through a new wavelet limited penetrable visibility graph (WLPVG) approach. This approach first decompose EEG into ?, ?, ?, ? sub-bands, then extracting nonlinear features from single channel signal, in addition forming a functional brain network for each sub-band. Manual acupuncture (MA) as a stimulation to the human nerve system, may evoke varied modulating effects in brain activities. To investigating whether and how this happens, WLPVG approach is used to analyze the EEGs of 15 healthy subjects with MA at acupoint ST36 on the right leg. It is found that MA can influence the complexity of EEG sub-bands in different ways and lead the functional brain networks to obtain higher efficiency and stronger small-world property compared with pre-acupuncture control state. PMID:25206935

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

    Microsoft Academic Search

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

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

  3. Structural plasticity of the adult brain: how animal models help us understand brain changes in depression and systemic disorders related to depression

    PubMed Central

    McEwen, Bruce S.

    2004-01-01

    The brain interprets experiences and translates them into behavioral and physiological responses. Stressful events are those which are threatening or, at the very least, unexpected and surprising, and the physiological and behavioral responses are intended to promote adaptation via a process called “allostasis. ” Chemical mediators of allostasis include cortisol and adrenalin from the adrenal glands, other hormones, and neurotransmitters, the parasympathetic and sympathetic nervous systems, and cytokines and chemokines from the immune system. Two brain structures, the amygdala and hippocampus, play key roles in interpreting what is stressful and determining appropriate responses. The hippocampus, a key structure for memories of events and contexts, expresses receptors that enable it to respond to glucocorticoid hormones in the blood, it undergoes atrophy in a number of psychiatric disorders; it also responds to stressors with changes in excitability, decreased dendritic branching, and reduction in number of neurons in the dentate gyrus. The amygdala, which is important for “emotional memories, ” becomes hyperactive in posttraumatic stress disorder and depressive illness, in animal models of stress, there is evidence for growth and hypertrophy of nerve cells in the amygdala. Changes in the brain after acute and chronic stressors mirror the pattern seen in the metabolic, cardiovascular, and immune systems, that is, short-term adaptation (allostasis) followed by long-term damage (allostatic load), eg, atherosclerosis, fat deposition obesity, bone demineralization, and impaired immune function. Allostatic load of this kind is seen in major depressive illness and may also be expressed in other chronic anxiety and mood disorders. PMID:22034132

  4. Androgens modulate structure and function of the suprachiasmatic nucleus brain clock.

    PubMed

    Karatsoreos, Ilia N; Butler, Matthew P; Lesauter, Joseph; Silver, Rae

    2011-05-01

    Gonadal hormones can modulate circadian rhythms in rodents and humans, and androgen receptors are highly localized within the core region of the mouse suprachiasmatic nucleus (SCN) brain clock. Although androgens are known to modulate neural plasticity in other CNS compartments, the role of androgens and their receptors on plasticity in the SCN is unexplored. In the present study, we ask whether androgens influence the structure and function of the mouse SCN by examining the effects of gonadectomy (GDX) on the structure of the SCN circuit and its responses to light, including induction of clock genes and behavioral phase shifting. We found that after GDX, glial fibrillary acidic protein increased with concomitant decreases in the expression of the synaptic proteins synaptophysin and postsynaptic density 95. We also found that GDX exerts effects on the molecular and behavioral responses to light that are phase dependent. In late night [circadian time (CT)21], GDX increased light-induced mPer1 but not mPer2 expression compared with intact (INT) controls. In contrast, in early night (CT13.5), GDX decreased light induced mPer2 but had no effect on mPer1. At CT13.5, GDX animals also showed larger phase delays than did INT. Treatment of GDX animals with the nonaromatizable androgen dihydrotestosterone restored glial fibrillary acidic protein, postsynaptic density 95, and synaptophysin in the SCN and reinstated the INT pattern of molecular and behavioral responses to light. Together, the results reveal a role for androgens in regulating circuitry in the mouse SCN, with functional consequences for clock gene expression and behavioral responses to photic phase resetting stimuli. PMID:21363939

  5. Cortical and subcortical plasticity in the brains of humans, primates, and rats after damage to sensory afferents in the dorsal columns of the spinal cord

    PubMed Central

    Kaas, Jon H.; Qi, Hui-Xin; Burish, Mark; Gharbawie, Omar; Onifer, Stephen M.; Massey, James M.

    2008-01-01

    The failure of injured axons to regenerate following spinal cord injury deprives brain neurons of their normal sources of activation. These injuries also result in the reorganization of affected areas of the central nervous system that is thought to drive both the ensuing recovery of function and the formation of maladaptive neuronal circuitry. Better understanding of the physiological consequences of novel synaptic connections produced by injury and the mechanisms that control their formation are important to the development of new successful strategies for the treatment of patients with spinal cord injuries. Here we discuss the anatomical, physiological and behavioral changes that take place in response to injury-induced plasticity after damage to the dorsal column pathway in rats and monkeys. Complete section of the dorsal columns of the spinal cord at a high cervical level in monkeys and rats interrupts the ascending axon branches of low threshold mechanoreceptor afferents subserving the forelimb and the rest of the lower body. Such lesions render the corresponding part of the somatotopic representation of primary somatosensory cortex totally unresponsive to tactile stimuli. There are also behavioral consequences of the sensory loss, including an impaired use of the hand/forelimb in manipulating small objects. In monkeys, if some of the afferents from the hand remain intact after dorsal column lesions, these remaining afferents extensively reactivate portions of somatosensory cortex formerly representing the hand. This functional reorganization develops over a postoperative period of one month, during which hand use rapidly improves. These recoveries appear to be mediated, at least in part, by the sprouting of preserved afferents within the cuneate nucleus of the dorsal column-trigeminal complex. In rats, such functional collateral sprouting has been promoted by the post-lesion digestion of the perineuronal net in the cuneate nucleus. Thus, this and other therapeutic strategies have the potential of enhancing sensorimotor recoveries after spinal cord injuries in humans. PMID:17692844

  6. Child Abuse, Depression, and Methylation in Genes Involved with Stress, Neural Plasticity, and Brain Circuitry

    PubMed Central

    Weder, Natalie; Zhang, Huiping; Jensen, Kevin; Yang, Bao Zhu; Simen, Arthur; Jackowski, Andrea; Lipschitz, Deborah; Douglas-Palumberi, Heather; Ge, Margrat; Perepletchikova, Francheska; O’Laughlin, Kerry; Hudziak, James J.; Gelernter, Joel; Kaufman, Joan

    2014-01-01

    Objectives Determine if epigenetic markers predict dimensional ratings of depression in maltreated children. Method A Genome-wide methylation study was completed using the Illumina 450K BeadChip array in 94 maltreated and 96 non-traumatized children with saliva-derived DNA. The 450K BeadChip does not include any methylation sites in the exact location as sites in candidate genes previously examined in the literature, so a test for replication of prior research findings was not feasible. Results Methylation in three genes emerged as genomewide-significant predictors of depression: DNA-Binding Protein Inhibitor ID-3 (ID3); Glutamate Receptor, Ionotropic NMDA 1 (GRIN1); and Tubulin Polymerization Promoting Protein (TPPP) (p<5.0 × 10?7, all analyses). These genes are all biologically relevant–with ID3 involved in the stress response, GRIN1 involved in neural plasticity, and TPPP involved in neural circuitry development. Methylation in CpG sites in candidate genes were not predictors of depression at significance levels corrected for whole genome testing, but maltreated and control children did have significantly different beta values after Bonferroni correction at multiple methylation sites in these candidate genes (e.g., BDNF, NR3C1, FKBP5). Conclusion This study suggests epigenetic changes in ID3, GRIN1, and TPPP genes, in combination with experiences of maltreatment, may confer risk for depression in children. It adds to a growing body of literature supporting a role for epigenetic mechanisms in the pathophysiology of stress-related psychiatric disorders. While epigenetic changes are frequently long lasting, they are not necessarily permanent. Consequently, interventions to reverse the negative biological and behavioral sequelae associated with child maltreatment are briefly discussed. PMID:24655651

  7. Please cite this article in press as: Will B, et al., Reflections on the use of the concept of plasticity in neurobiology, Behav Brain Res (2008), doi:10.1016/j.bbr.2007.11.008

    E-print Network

    Hickman, Mark

    2008-01-01

    of plasticity in neurobiology, Behav Brain Res (2008), doi:10.1016/j.bbr.2007.11.008 ARTICLE IN PRESS+Model BBR in neurobiology Translation and adaptation by Bruno Will, John Dalrymple-Alford, Mathieu Wolff and Jean the ambiguities of the concept of plasticity and the dangers of its purely metaphoric use in neurobiology

  8. Plasticity in the Human Visual Cortex: An Ophthalmology-Based Perspective

    PubMed Central

    Rosa, Andreia Martins; Silva, Maria Fátima; Murta, Joaquim

    2013-01-01

    Neuroplasticity refers to the ability of the brain to reorganize the function and structure of its connections in response to changes in the environment. Adult human visual cortex shows several manifestations of plasticity, such as perceptual learning and adaptation, working under the top-down influence of attention. Plasticity results from the interplay of several mechanisms, including the GABAergic system, epigenetic factors, mitochondrial activity, and structural remodeling of synaptic connectivity. There is also a downside of plasticity, that is, maladaptive plasticity, in which there are behavioral losses resulting from plasticity changes in the human brain. Understanding plasticity mechanisms could have major implications in the diagnosis and treatment of ocular diseases, such as retinal disorders, cataract and refractive surgery, amblyopia, and in the evaluation of surgical materials and techniques. Furthermore, eliciting plasticity could open new perspectives in the development of strategies that trigger plasticity for better medical and surgical outcomes. PMID:24205505

  9. Roles for Oestrogen Receptor ? in Adult Brain Function

    PubMed Central

    Handa, R. J.; Ogawa, S.; Wang, J. M.; Herbison, A. E.

    2012-01-01

    Oestradiol exerts a profound influence upon multiple brain circuits. For the most part, these effects are mediated by oestrogen receptor (ER)?. We review here the roles of ER?, the other ER isoform, in mediating rodent oestradiol-regulated anxiety, aggressive and sexual behaviours, the control of gonadotrophin secretion, and adult neurogenesis. Evidence exists for: (i) ER? located in the paraventricular nucleus underpinning the suppressive influence of oestradiol on the stress axis and anxiety-like behaviour; (ii) ER? expressed in gonadotrophin-releasing hormone neurones contributing to oestrogen negative-feedback control of gonadotrophin secretion; (iii) ER? controlling the offset of lordosis behaviour; (iv) ER? suppressing aggressive behaviour in males; (v) ER? modulating responses to social stimuli; and (vi) ER? in controlling adult neurogenesis. This review highlights two major themes; first, ER? and ER? are usually tightly inter-related in the oestradiol-dependent control of a particular brain function. For example, even though oestradiol feedback to control reproduction occurs principally through ER?-dependent mechanisms, modulatory roles for ER? also exist. Second, the roles of ER? and ER? within a particular neural network may be synergistic or antagonistic. Examples of the latter include the role of ER? to enhance, and ER? to suppress, anxiety-like and aggressive behaviours. Splice variants such as ER?2, acting as dominant negative receptors, are of further particular interest because their expression levels may reflect preceeding oestradiol exposure of relevance to oestradiol replacement therapy. Together, this review highlights the predominant modulatory, but nonetheless important, roles of ER? in mediating the many effects of oestradiol upon adult brain function. PMID:21851428

  10. Intrinsic Functional Plasticity of the Sensorimotor Network in Relapsing-Remitting Multiple Sclerosis: Evidence from a Centrality Analysis

    PubMed Central

    Zhuang, Ying; Zhou, Fuqing; Gong, Honghan.

    2015-01-01

    Background and Purpose Advanced MRI studies have revealed regional alterations in the sensorimotor cortex of patients with relapsing-remitting multiple sclerosis (RRMS). However, the organizational features underlying the relapsing phase and the subsequent remitting phase have not been directly shown at the functional network or the connectome level. Therefore, this study aimed to characterize MS-related centrality disturbances of the sensorimotor network (SMN) and to assess network integrity and connectedness. Methods Thirty-four patients with clinically definite RRMS and well-matched healthy controls participated in the study. Twenty-three patients in the remitting phase underwent one resting-state functional MRI, and 11 patients in the relapsing-remitting phase underwent two different MRIs. We measured voxel-wise centrality metrics to determine direct (degree centrality, DC) and global (eigenvector centrality, EC) functional relationships across the entire SMN. Results In the relapsing phase, DC was significantly decreased in the bilateral primary motor and somatosensory cortex (M1/S1), left dorsal premotor (PMd), and operculum-integrated regions. However, DC was increased in the peripheral SMN areas. The decrease in DC in the bilateral M1/S1 was associated with the expanded disability status scale (EDSS) and total white matter lesion loads (TWMLLs), suggesting that this adaptive response is related to the extent of brain damage in the rapid-onset attack stage. During the remission process, these alterations in centrality were restored in the bilateral M1/S1 and peripheral SMN areas. In the remitting phase, DC was reduced in the premotor, supplementary motor, and operculum-integrated regions, reflecting an adaptive response due to brain atrophy. However, DC was enhanced in the right M1 and left parietal-integrated regions, indicating chronic reorganization. In both the relapsing and remitting phases, the changes in EC and DC were similar. Conclusions The alterations in centrality within the SMN indicate rapid plasticity and chronic reorganization with a biased impairment of specific functional areas in RRMS patients. PMID:26110420

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

    E-print Network

    Mueller, Klaus

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

  12. Estimating brain functional connectivity with sparse multivariate autoregression

    PubMed Central

    Valdés-Sosa, Pedro A; Sánchez-Bornot, Jose M; Lage-Castellanos, Agustín; Vega-Hernández, Mayrim; Bosch-Bayard, Jorge; Melie-García, Lester; Canales-Rodríguez, Erick

    2005-01-01

    There is much current interest in identifying the anatomical and functional circuits that are the basis of the brain's computations, with hope that functional neuroimaging techniques will allow the in vivo study of these neural processes through the statistical analysis of the time-series they produce. Ideally, the use of techniques such as multivariate autoregressive (MAR) modelling should allow the identification of effective connectivity by combining graphical modelling methods with the concept of Granger causality. Unfortunately, current time-series methods perform well only for the case that the length of the time-series Nt is much larger than p, the number of brain sites studied, which is exactly the reverse of the situation in neuroimaging for which relatively short time-series are measured over thousands of voxels. Methods are introduced for dealing with this situation by using sparse MAR models. These can be estimated in a two-stage process involving (i) penalized regression and (ii) pruning of unlikely connections by means of the local false discovery rate developed by Efron. Extensive simulations were performed with idealized cortical networks having small world topologies and stable dynamics. These show that the detection efficiency of connections of the proposed procedure is quite high. Application of the method to real data was illustrated by the identification of neural circuitry related to emotional processing as measured by BOLD. PMID:16087441

  13. Functional specializations for music processing in the human newborn brain.

    PubMed

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

    2010-03-01

    In adults, specific neural systems with right-hemispheric weighting are necessary to process pitch, melody, and harmony as well as structure and meaning emerging from musical sequences. It is not known to what extent the specialization of these systems results from long-term exposure to music or from neurobiological constraints. One way to address this question is to examine how these systems function at birth, when auditory experience is minimal. We used functional MRI to measure brain activity in 1- to 3-day-old newborns while they heard excerpts of Western tonal music and altered versions of the same excerpts. Altered versions either included changes of the tonal key or were permanently dissonant. Music evoked predominantly right-hemispheric activations in primary and higher order auditory cortex. During presentation of the altered excerpts, hemodynamic responses were significantly reduced in the right auditory cortex, and activations emerged in the left inferior frontal cortex and limbic structures. These results demonstrate that the infant brain shows a hemispheric specialization in processing music as early as the first postnatal hours. Results also indicate that the neural architecture underlying music processing in newborns is sensitive to changes in tonal key as well as to differences in consonance and dissonance. PMID:20176953

  14. Functional Tissue Pulsatility Imaging of the Brain during Visual Stimulation

    PubMed Central

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

    2007-01-01

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

  15. Age-dependent effects of chronic stress on brain plasticity and depressive behavior.

    PubMed

    Toth, Erika; Gersner, Roman; Wilf-Yarkoni, Adi; Raizel, Hagit; Dar, Dalit E; Richter-Levin, Gal; Levit, Ofir; Zangen, Abraham

    2008-10-01

    Exposure to chronic mild stress (CMS) is known to induce anhedonia in adult animals, and is associated with induction of depression in humans. However, the behavioral effects of CMS in young animals have not yet been characterized, and little is known about the long-term neurochemical effects of CMS in either young or adult animals. Here, we found that CMS induces anhedonia in adult but not in young animals, as measured by a set of behavioral paradigms. Furthermore, while CMS decreased neurogenesis and levels of brain-derived neurotrophic factor (BDNF) in the hippocampus of adult animals, it increased these parameters in young animals. We also found that CMS altered alpha-amino-3-hydroxy-5-methylisoxazole-4-propionate (AMPA) receptor GluR1 subunit levels in the hippocampus and the nucleus accumbens of adult, but not young animals. Finally, no significant differences were observed between the effects of CMS on circadian corticosterone levels in the different age groups. The substantially different neurochemical effects chronic stress exerts in young and adult animals may explain the behavioral resilience to such stress young animals possess. PMID:18752645

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

    Microsoft Academic Search

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

    2010-01-01

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

  17. Development/Plasticity/Repair Turning Astrocytes from the Rostral Migratory Stream into

    E-print Network

    Paris-Sud XI, Université de

    Development/Plasticity/Repair Turning Astrocytes from the Rostral Migratory Stream into Neurons within a few restricted areas of the adult mammalian brain, giving rise to neurons that functionally confirmandconsiderablyextendrecentevidencefortheexistenceofadultneuralstemcellswithintheRMS,andgoontoinvestigatetheir proliferative regulation. Specifically targeting RMS-astrocytes

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

    PubMed

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

    2014-11-01

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

  19. Disrupted Brain Functional Organization in Epilepsy Revealed by Graph Theory Analysis.

    PubMed

    Song, Jie; Nair, Veena A; Gaggl, Wolfgang; Prabhakaran, Vivek

    2015-06-01

    The human brain is a complex and dynamic system that can be modeled as a large-scale brain network to better understand the reorganizational changes secondary to epilepsy. In this study, we developed a brain functional network model using graph theory methods applied to resting-state fMRI data acquired from a group of epilepsy patients and age- and gender-matched healthy controls. A brain functional network model was constructed based on resting-state functional connectivity. A minimum spanning tree combined with proportional thresholding approach was used to obtain sparse connectivity matrices for each subject, which formed the basis of brain networks. We examined the brain reorganizational changes in epilepsy thoroughly at the level of the whole brain, the functional network, and individual brain regions. At the whole-brain level, local efficiency was significantly decreased in epilepsy patients compared with the healthy controls. However, global efficiency was significantly increased in epilepsy due to increased number of functional connections between networks (although weakly connected). At the functional network level, there were significant proportions of newly formed connections between the default mode network and other networks and between the subcortical network and other networks. There was a significant proportion of decreasing connections between the cingulo-opercular task control network and other networks. Individual brain regions from different functional networks, however, showed a distinct pattern of reorganizational changes in epilepsy. These findings suggest that epilepsy alters brain efficiency in a consistent pattern at the whole-brain level, yet alters brain functional networks and individual brain regions differently. PMID:25647011

  20. Microglia in neuronal plasticity: Influence of stress.

    PubMed

    Delpech, Jean-Christophe; Madore, Charlotte; Nadjar, Agnes; Joffre, Corinne; Wohleb, Eric S; Layé, Sophie

    2015-09-01

    The central nervous system (CNS) has previously been regarded as an immune-privileged site with the absence of immune cell responses but this dogma was not entirely true. Microglia are the brain innate immune cells and recent findings indicate that they participate both in CNS disease and infection as well as facilitate normal CNS function. Microglia are highly plastic and play integral roles in sculpting the structure of the CNS, refining neuronal circuitry and connectivity, and contribute actively to neuronal plasticity in the healthy brain. Interestingly, psychological stress can perturb the function of microglia in association with an impaired neuronal plasticity and the development of emotional behavior alterations. As a result it seemed important to describe in this review some findings indicating that the stress-induced microglia dysfunction may underlie neuroplasticity deficits associated to many mood disorders. This article is part of a Special Issue entitled 'Neuroimmunology and Synaptic Function'. PMID:25582288

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

    Microsoft Academic Search

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

    2010-01-01

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

  2. Functional Representation of Human Embryo Brain Models Roman Durikovic Silvester Czanner

    E-print Network

    Durikovic, Roman

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

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

    Microsoft Academic Search

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

    2001-01-01

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

  4. NEST Scientific Report 2007-2009 Monitoring brain function by in vivo 2-photon microscopy

    E-print Network

    Abbondandolo, Alberto

    101) selectively stain and identify a population of brain cells, the astrocytes. The green dyeNEST Scientific Report 2007-2009 Monitoring brain function by in vivo 2-photon microscopy 75) transversal reconstruction of a brain neuron. The cell body is placed in cortical layer V at a depth of over

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

    Microsoft Academic Search

    Olaf Sporns; Ed Bullmore

    2009-01-01

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

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

    E-print Network

    Kanwisher, Nancy

    brain region previously implicated in language (e.g., Broca's area), without a direct demonstrationFunctional specificity for high-level linguistic processing in the human brain Evelina Fedorenkoa,1 , Michael K. Behra , and Nancy Kanwishera,b,1 a Brain and Cognitive Sciences Department and b Mc

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

    Microsoft Academic Search

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

    2006-01-01

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

  8. Functional and morphometric brain dissociation between dyslexia and reading ability.

    PubMed

    Hoeft, Fumiko; Meyler, Ann; Hernandez, Arvel; Juel, Connie; Taylor-Hill, Heather; Martindale, Jennifer L; McMillon, Glenn; Kolchugina, Galena; Black, Jessica M; Faizi, Afrooz; Deutsch, Gayle K; Siok, Wai Ting; Reiss, Allan L; Whitfield-Gabrieli, Susan; Gabrieli, John D E

    2007-03-01

    In functional neuroimaging studies, individuals with dyslexia frequently exhibit both hypoactivation, often in the left parietotemporal cortex, and hyperactivation, often in the left inferior frontal cortex, but there has been no evidence to suggest how to interpret the differential relations of hypoactivation and hyperactivation to dyslexia. To address this question, we measured brain activation by functional MRI during visual word rhyme judgment compared with visual cross-hair fixation rest, and we measured gray matter morphology by voxel-based morphometry in dyslexic adolescents in comparison with (i) an age-matched group, and (ii) a reading-matched group younger than the dyslexic group but equal to the dyslexic group in reading performance. Relative to the age-matched group (n = 19; mean 14.4 years), the dyslexic group (n = 19; mean 14.4 years) exhibited hypoactivation in left parietal and bilateral fusiform cortices and hyperactivation in left inferior and middle frontal gyri, caudate, and thalamus. Relative to the reading-matched group (n = 12; mean 9.8 years), the dyslexic group (n = 12; mean 14.5 years) also exhibited hypoactivation in left parietal and fusiform regions but equal activation in all four areas that had exhibited hyperactivation relative to age-matched controls as well. In regions that exhibited atypical activation in the dyslexic group, only the left parietal region exhibited reduced gray matter volume relative to both control groups. Thus, areas of hyperactivation in dyslexia reflected processes related to the level of current reading ability independent of dyslexia. In contrast, areas of hypoactivation in dyslexia reflected functional atypicalities related to dyslexia itself, independent of current reading ability, and related to atypical brain morphology in dyslexia. PMID:17360506

  9. Imaging Odor Coding and Synaptic Plasticity in the Mammalian Brain with a Genetically-Encoded Probe

    Microsoft Academic Search

    J. P. McGann; N. Pirez; M. Wachowiak

    2006-01-01

    We have used the genetically-encoded fluorescent exocytosis indicator synaptopHluorin (spH), expressed selectively in mouse olfactory receptor neurons, to image odor representations at the input to the olfactory bulb. The olfactory bulb is a powerful system for in vivo fluorescence imaging because its inputs are segregated into receptor-specific functional units (glomeruli) that are optically accessible and receive massively convergent input from

  10. Relation of executive functioning and social communication measures to functional outcomes following traumatic brain injury.

    PubMed

    Struchen, Margaret A; Clark, Allison N; Sander, Angelle M; Mills, Monique R; Evans, Gina; Kurtz, Diana

    2008-01-01

    Neuropsychologists are increasingly asked to provide recommendations regarding functional abilities based on test results, particularly within the rehabilitation setting. Yet, the empirical basis for making such recommendations is limited. The current study examines relationships between executive functioning and social communication measures and concurrently measured occupational and social integration outcomes. Participants were 121 individuals with traumatic brain injury (TBI) recruited from participants in a longitudinal study of outcome following TBI who had all received comprehensive brain injury rehabilitation. As part of a larger study designed to evaluate social communication abilities following TBI, participants completed measures of executive functioning, affect perception, perceived communication ability, and functional outcome. After adjusting for age, education, and performance on executive functioning measures, social communication performance accounted for a unique 5.6% of the variance in occupational outcomes and 7.9% of variance in social integration outcomes. Executive functioning performance accounted for a unique 13.3% of the variance in occupational functioning and 16.0% of explained variance in social integration. These results provide evidence of the value of executive functioning and social communication measures in the prediction of functional outcomes. Additionally, such results provide preliminary support for the addition of social communication measures to assessment of TBI in neuropsychological practice. PMID:18525140

  11. The Brain’s Orienting Response: An Event-Related Functional Magnetic Resonance Imaging Investigation

    PubMed Central

    Friedman, David; Goldman, Robin; Stern, Yaakov; Brown, Truman R.

    2009-01-01

    An important function of the brain’s orienting response is to enable the evaluation of novel, environmental events in order to prepare for potential behavioral action. Here, we assessed the event-related hemodynamic (erfMRI) correlates of this phenomenon using unexpected (i.e., novel) environmental sounds presented within the context of an auditory novelty oddball paradigm. In ERP investigations of the novelty oddball, repetition of the identical novel sound leads to habituation of the novelty P3, an ERP sign of the orienting response. Repetition also leads to an enhancement of a subsequent positivity that appears to reflect semantic analysis of the environmental sounds. In this adaptation for erfMRI recording, frequent tones were intermixed randomly with infrequent target tones and equally infrequent novel, environmental sounds. Subjects responded via speeded button press to targets. To assess habituation, some of the environmental sounds were repeated 2 blocks after their initial presentation. As expected, novel sounds and target tones led to activation of widespread, but somewhat different, neural networks. Contrary to expectation, however, there were no significant areas in which activation was reduced in response to second compared to first presentations of the novel sounds. Conversely, novel sounds relative to target tones engendered activity in the inferior frontal gyrus (BA 45) consistent with semantic analysis of these events. We conclude that a key concomitant of the orienting response is the extraction of meaning, thereby enabling one to determine the significance of the environmental perturbation and take appropriate goal-directed action. PMID:18465750

  12. Selectionist and Evolutionary Approaches to Brain Function: A Critical Appraisal

    PubMed Central

    Fernando, Chrisantha; Szathmáry, Eörs; Husbands, Phil

    2012-01-01

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

  13. Development and Plasticity of Intra- and Intersensory Information Processing

    PubMed Central

    Polley, Daniel B.; Hillock, Andrea R.; Spankovich, Christopher; Popescu, Maria V.; Royal, David W.; Wallace, Mark T.

    2013-01-01

    The functional architecture of sensory brain regions reflects an ingenious biological solution to the competing demands of a continually changing sensory environment. While they are malleable, they have the constancy necessary to support a stable sensory percept. How does the functional organization of sensory brain regions contend with these antithetical demands? Here we describe the functional organization of auditory and multisensory (i.e., auditory-visual) information processing in three sensory brain structures: (1) a low-level unisensory cortical region, the primary auditory cortex (A1); (2) a higher-order multisensory cortical region, the anterior ectosylvian sulcus (AES); and (3) a multisensory subcortical structure, the superior colliculus (SC), We then present a body of work that characterizes the ontogenic expression of experience-dependent influences on the operations performed by the functional circuits contained within these regions. We will present data to support the hypothesis that the competing demands for plasticity and stability are addressed through a developmental transition in operational properties of functional circuits from an initially labile mode in the early stages of postnatal development to a more stable mode in the mature brain that retains the capacity for plasticity under specific experiential conditions. Finally, we discuss parallels between the central tenets of functional organization and plasticity of sensory brain structures drawn from animal studies and a growing literature on human brain plasticity and the potential applicability of these principles to the audiology clinic. PMID:19358458

  14. VEGF induces sensory and motor peripheral plasticity, alters bladder function, and promotes visceral sensitivity

    PubMed Central

    2012-01-01

    Background This work tests the hypothesis that bladder instillation with vascular endothelial growth factor (VEGF) modulates sensory and motor nerve plasticity, and, consequently, bladder function and visceral sensitivity. In addition to C57BL/6J, ChAT-cre mice were used for visualization of bladder cholinergic nerves. The direct effect of VEGF on the density of sensory nerves expressing the transient receptor potential vanilloid subfamily 1 (TRPV1) and cholinergic nerves (ChAT) was studied one week after one or two intravesical instillations of the growth factor. To study the effects of VEGF on bladder function, mice were intravesically instilled with VEGF and urodynamic evaluation was assessed. VEGF-induced alteration in bladder dorsal root ganglion (DRG) neurons was performed on retrogradly labeled urinary bladder afferents by patch-clamp recording of voltage gated Na+ currents. Determination of VEGF-induced changes in sensitivity to abdominal mechanostimulation was performed by application of von Frey filaments. Results In addition to an overwhelming increase in TRPV1 immunoreactivity, VEGF instillation resulted in an increase in ChAT-directed expression of a fluorescent protein in several layers of the urinary bladder. Intravesical VEGF caused a profound change in the function of the urinary bladder: acute VEGF (1 week post VEGF treatment) reduced micturition pressure and longer treatment (2 weeks post-VEGF instillation) caused a substantial reduction in inter-micturition interval. In addition, intravesical VEGF resulted in an up-regulation of voltage gated Na+ channels (VGSC) in bladder DRG neurons and enhanced abdominal sensitivity to mechanical stimulation. Conclusions For the first time, evidence is presented indicating that VEGF instillation into the mouse bladder promotes a significant increase in peripheral nerve density together with alterations in bladder function and visceral sensitivity. The VEGF pathway is being proposed as a key modulator of neural plasticity in the pelvis and enhanced VEGF content may be associated with visceral hyperalgesia, abdominal discomfort, and/or pelvic pain. PMID:23249422

  15. Vascular endothelial growth factor-dependent angiogenesis and dynamic vascular plasticity in the sensory circumventricular organs of adult mouse brain.

    PubMed

    Morita, Shoko; Furube, Eriko; Mannari, Tetsuya; Okuda, Hiroaki; Tatsumi, Kouko; Wanaka, Akio; Miyata, Seiji

    2015-03-01

    The sensory circumventricular organs (CVOs), which comprise the organum vasculosum of the lamina terminalis (OVLT), the subfornical organ (SFO) and the area postrema (AP), lack a typical blood-brain barrier (BBB) and monitor directly blood-derived information to regulate body fluid homeostasis, inflammation, feeding and vomiting. Until now, almost nothing has been documented about vascular features of the sensory CVOs except fenestration of vascular endothelial cells. We therefore examine whether continuous angiogenesis occurs in the sensory CVOs of adult mouse. The angiogenesis-inducing factor vascular endothelial growth factor-A (VEGF-A) and the VEGF-A-regulating transcription factor hypoxia-inducible factor-1? were highly expressed in neurons of the OVLT and SFO and in both neurons and astrocytes of the AP. Expression of the pericyte-regulating factor platelet-derived growth factor B was high in astrocytes of the sensory CVOs. Immunohistochemistry of bromodeoxyuridine and Ki-67, a nuclear protein that is associated with cellular proliferation, revealed active proliferation of endothelial cells. Moreover, immunohistochemistry of caspase-3 and the basement membrane marker laminin showed the presence of apoptosis and sprouting of endothelial cells, respectively. Treatment with the VEGF receptor-associated tyrosine kinase inhibitor AZD2171 significantly reduced proliferation and filopodia sprouting of endothelial cells, as well as the area and diameter of microvessels. The mitotic inhibitor cytosine-b-D-arabinofuranoside reduced proliferation of endothelial cells and the vascular permeability of blood-derived low-molecular-weight molecules without changing vascular area and microvessel diameter. Thus, our data indicate that continuous angiogenesis is dependent on VEGF signaling and responsible for the dynamic plasticity of vascular structure and permeability. PMID:25573819

  16. Structural plasticity associated with exposure to drugs of abuse

    Microsoft Academic Search

    Terry E. Robinson; Bryan Kolb

    2004-01-01

    Persistent changes in behavior and psychological function that occur as a function of experience, such those associated with learning and memory, are thought to be due to the reorganization of synaptic connections (structural plasticity) in relevant brain circuits. Some of the most compelling examples of experience-dependent changes in behavior and psychological function, changes that can last a lifetime, are those

  17. Evolution of human brain functions: the functional structure of human consciousness.

    PubMed

    Cloninger, C Robert

    2009-11-01

    The functional structure of self-aware consciousness in human beings is described based on the evolution of human brain functions. Prior work on heritable temperament and character traits is extended to account for the quantum-like and holographic properties (i.e. parts elicit wholes) of self-aware consciousness. Cladistic analysis is used to identify the succession of ancestors leading to human beings. The functional capacities that emerge along this lineage of ancestors are described. The ecological context in which each cladogenesis occurred is described to illustrate the shifting balance of evolution as a complex adaptive system. Comparative neuroanatomy is reviewed to identify the brain structures and networks that emerged coincident with the emergent brain functions. Individual differences in human temperament traits were well developed in the common ancestor shared by reptiles and humans. Neocortical development in mammals proceeded in five major transitions: from early reptiles to early mammals, early primates, simians, early Homo, and modern Homo sapiens. These transitions provide the foundation for human self-awareness related to sexuality, materiality, emotionality, intellectuality, and spirituality, respectively. The functional structure of human self-aware consciousness is concerned with the regulation of five planes of being: sexuality, materiality, emotionality, intellectuality, and spirituality. Each plane elaborates neocortical functions organized around one of the five special senses. The interactions among these five planes gives rise to a 5 x 5 matrix of subplanes, which are functions that coarsely describe the focus of neocortical regulation. Each of these 25 neocortical functions regulates each of five basic motives or drives that can be measured as temperaments or basic emotions related to fear, anger, disgust, surprise, and happiness/sadness. The resulting 5 x 5 x 5 matrix of human characteristics provides a general and testable model of the functional structure of human consciousness that includes personality, physicality, emotionality, cognition, and spirituality in a unified developmental framework. PMID:20001395

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

    PubMed

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

    2015-06-01

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

  19. Neuronal and Cognitive Plasticity: A Neurocognitive Framework for Ameliorating Cognitive Aging

    PubMed Central

    Greenwood, Pamela M.; Parasuraman, Raja

    2010-01-01

    What is the neurocognitive basis for the considerable individual differences observed in functioning of the adult mind and brain late in life? We review the evidence that in healthy old age the brain remains capable of both neuronal and cognitive plasticity, including in response to environmental and experiential factors. Neuronal plasticity (e.g., neurogenesis, synaptogenesis, cortical re-organization) refers to neuron-level changes that can be stimulated by experience. Cognitive plasticity (e.g., increased dependence on executive function) refers to adaptive changes in patterns of cognition related to brain activity. We hypothesize that successful cognitive aging requires interactions between these two forms of plasticity. Mechanisms of neural plasticity underpin cognitive plasticity and in turn, neural plasticity is stimulated by cognitive plasticity. We examine support for this hypothesis by considering evidence that neural plasticity is stimulated by learning and novelty and enhanced by both dietary manipulations (low-fat, dietary restriction) and aerobic exercise. We also examine evidence that cognitive plasticity is affected by education and training. This is a testable hypothesis which could be assessed in humans in randomized trials comparing separate and combined effects of cognitive training, exercise, and diet on measures of cognitive and brain integrity. Greater understanding of the factors influencing the course of cognitive aging and of the mechanisms underlying those factors could provide information on which people could base choices that improve their ability to age successfully. PMID:21151819

  20. Imaging local brain function with emission computed tomography

    SciTech Connect

    Kuhl, D.E.

    1984-03-01

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

  1. Noninvasive brain stimulation with transcranial magnetic or direct current stimulation (TMS\\/tDCS)—From insights into human memory to therapy of its dysfunction

    Microsoft Academic Search

    Roland Sparing; Felix M. Mottaghy

    2008-01-01

    Noninvasive stimulation of the brain by means of transcranial magnetic stimulation (TMS) or transcranial direct current stimulation (tDCS) has driven important discoveries in the field of human memory functions. Stand-alone or in combination with other brain mapping techniques noninvasive brain stimulation can assess issues such as location and timing of brain activity, connectivity and plasticity of neural circuits and functional

  2. Functional brain changes underlying irritability in premanifest Huntington's disease.

    PubMed

    Van den Stock, Jan; De Winter, François-Laurent; Ahmad, Rawaha; Sunaert, Stefan; Van Laere, Koen; Vandenberghe, Wim; Vandenbulcke, Mathieu

    2015-07-01

    The clinical phenotype of Huntington's disease (HD) consists of motor, cognitive and psychiatric symptoms, of which irritability is an important manifestation. Our aim was to identify the functional and structural brain changes that underlie irritability in premanifest HD (preHD). Twenty preHD carriers and 20 gene-negative controls from HD families took part in the study. Although the 5-year probability of disease onset was only 11%, the preHD group showed striatal atrophy and increased clinical irritability ratings. Functional MRI was performed during a mood induction experiment by means of recollection of emotional (angry, sad, and happy) and neutral autobiographical episodes. While there were no significant group differences in the subjective intensity of the emotional experience, the preHD group showed increased anger-selective activation in a distributed network, including the pulvinar, cingulate cortex, and somatosensory association cortex, compared to gene-negative controls. Pulvinar activation during anger experience correlated negatively with putaminal grey matter volume and positively with irritability ratings in the preHD group. In addition, the preHD group showed a decrease in anger-selective activation in the amygdala, which correlated with putaminal and caudate grey matter volume. In conclusion, compared to gene-negative controls, anger experience in preHD is associated with activity changes in a distributed set of regions known to be involved in emotion regulation. Increased activity is related to behavioral and volumetric measures, providing insight in the pathophysiology of early neuropsychiatric symptoms in preHD. Hum Brain Mapp 36:2681-2690, 2015. © 2015 Wiley Periodicals, Inc. PMID:25858294

  3. Drawing enhances cross-modal memory plasticity in the human brain: a case study in a totally blind adult

    PubMed Central

    Likova, Lora T.

    2012-01-01

    In a memory-guided drawing task under blindfolded conditions, we have recently used functional Magnetic Resonance Imaging (fMRI) to demonstrate that the primary visual cortex (V1) may operate as the visuo-spatial buffer, or “sketchpad,” for working memory. The results implied, however, a modality-independent or amodal form of its operation. In the present study, to validate the role of V1 in non-visual memory, we eliminated not only the visual input but all levels of visual processing by replicating the paradigm in a congenitally blind individual. Our novel Cognitive-Kinesthetic method was used to train this totally blind subject to draw complex images guided solely by tactile memory. Control tasks of tactile exploration and memorization of the image to be drawn, and memory-free scribbling were also included. FMRI was run before training and after training. Remarkably, V1 of this congenitally blind individual, which before training exhibited noisy, immature, and non-specific responses, after training produced full-fledged response time-courses specific to the tactile-memory drawing task. The results reveal the operation of a rapid training-based plasticity mechanism that recruits the resources of V1 in the process of learning to draw. The learning paradigm allowed us to investigate for the first time the evolution of plastic re-assignment in V1 in a congenitally blind subject. These findings are consistent with a non-visual memory involvement of V1, and specifically imply that the observed cortical reorganization can be empowered by the process of learning to draw. PMID:22593738

  4. Dynamic reorganization of brain functional networks during cognition.

    PubMed

    Bola, Micha?; Sabel, Bernhard A

    2015-07-01

    How does cognition emerge from neural dynamics? The dominant hypothesis states that interactions among distributed brain regions through phase synchronization give basis for cognitive processing. Such phase-synchronized networks are transient and dynamic, established on the timescale of milliseconds in order to perform specific cognitive operations. But unlike resting-state networks, the complex organization of transient cognitive networks is typically not characterized within the graph theory framework. Thus, it is not known whether cognitive processing merely changes the strength of functional connections or, conversely, requires qualitatively new topological arrangements of functional networks. To address this question, we recorded high-density EEG while subjects performed a visual discrimination task. We conducted an event-related network analysis (ERNA) where source-space weighted functional networks were characterized with graph measures. ERNA revealed rapid, transient, and frequency-specific reorganization of the network's topology during cognition. Specifically, cognitive networks were characterized by strong clustering, low modularity, and strong interactions between hub-nodes. Our findings suggest that dense and clustered connectivity between the hub nodes belonging to different modules is the "network fingerprint" of cognition. Such reorganization patterns might facilitate global integration of information and provide a substrate for a "global workspace" necessary for cognition and consciousness to occur. Thus, characterizing topology of the event-related networks opens new vistas to interpret cognitive dynamics in the broader conceptual framework of graph theory. PMID:25828884

  5. Neurovascular coupling: in vivo optical techniques for functional brain imaging

    PubMed Central

    2013-01-01

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

  6. Mechanism-based inhibition of the melatonin rhythm enzyme: Pharmacologic exploitation of active site functional plasticity

    PubMed Central

    Khalil, Ehab M.; De Angelis, Jacqueline; Ishii, Makoto; Cole, Philip A.

    1999-01-01

    Serotonin N-acetyltransferase is the enzyme responsible for the diurnal rhythm of melatonin production in the pineal gland of animals and humans. Inhibitors of this enzyme active in cell culture have not been reported previously. The compound N-bromoacetyltryptamine was shown to be a potent inhibitor of this enzyme in vitro and in a pineal cell culture assay (IC50 ? 500 nM). The mechanism of inhibition is suggested to involve a serotonin N-acetyltransferase-catalyzed alkylation reaction between N-bromoacetyltryptamine and reduced CoA, resulting in the production of a tight-binding bisubstrate analog inhibitor. This alkyltransferase activity is apparently catalyzed at a functionally distinct site compared with the acetyltransferase activity active site on serotonin N-acetyltransferase. Such active site plasticity is suggested to result from a subtle conformational alteration in the protein. This plasticity allows for an unusual form of mechanism-based inhibition with multiple turnovers, resulting in “molecular fratricide.” N-bromoacetyltryptamine should serve as a useful tool for dissecting the role of melatonin in circadian rhythm as well as a potential lead compound for therapeutic use in mood and sleep disorders. PMID:10535937

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

    PubMed

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

    2014-10-01

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

  8. Plasticity of multisensory dorsal stream functions: evidence from congenitally blind and sighted adults.

    PubMed

    Fiehler, Katja; Rösler, Frank

    2010-01-01

    The dorsal stream has been proposed to compute vision for space perception and for the control of action. However, perceiving space and guiding movements is not only based on vision but also on other sensory modalities such as proprioception and kinesthesia. Blind people who lost vision early in life provide an exceptional example to study the plasticity of dorsal stream functions. Using fMRI and psychophysical methods, action control and space perception was investigated in congenitally blind and sighted adults while performing active and passive hand movements without visual feedback. The functional imaging data showed largely overlapping activation patterns for kinesthetically guided hand movements in congenitally blind and sighted participants covering regions of the dorsal stream. In contrast to the sighted participants, congenitally blind participants additionally activated the extrastriate cortex and the auditory cortex. The psychophysical results revealed a significant correlation between proprioceptive spatial discrimination acuity of the blind and the age when they had attended an orientation and mobility training, i.e., an extensive non-visual spatial training. The earlier the blind acquired such a spatial training the more accurate and the more precise was their space perception in later life. Our findings suggest a multisensory network of movement control that develops on the basis of sensorimotor feedback rather than being under the exclusive control of vision. Thus, visual deprivation seems to result in both cross-modal and compensatory intra-modal plasticity. The present findings further imply that dorsal stream functions are shaped by non-visual spatial information during early development. PMID:20404408

  9. The impact of alcohol dependence on social brain function.

    PubMed

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

    2013-01-01

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

  10. Noninvasive and painless magnetic stimulation of nerves improved brain motor function and mobility in a cerebral palsy case.

    PubMed

    Flamand, Véronique H; Schneider, Cyril

    2014-10-01

    Motor deficits in cerebral palsy disturb functional independence. This study tested whether noninvasive and painless repetitive peripheral magnetic stimulation could improve motor function in a 7-year-old boy with spastic hemiparetic cerebral palsy. Stimulation was applied over different nerves of the lower limbs for 5 sessions. We measured the concurrent aftereffects of this intervention on ankle motor control, gait (walking velocity, stride length, cadence, cycle duration), and function of brain motor pathways. We observed a decrease of ankle plantar flexors resistance to stretch, an increase of active dorsiflexion range of movement, and improvements of corticospinal control of ankle dorsiflexors. Joint mobility changes were still present 15 days after the end of stimulation, when all gait parameters were also improved. Resistance to stretch was still lower than prestimulation values 45 days after the end of stimulation. This case illustrates the sustained effects of repetitive peripheral magnetic stimulation on brain plasticity, motor function, and gait. It suggests a potential impact for physical rehabilitation in cerebral palsy. PMID:24907638

  11. Receptor protein tyrosine phosphatase sigma regulates synapse structure, function and plasticity.

    PubMed

    Horn, Katherine E; Xu, Bin; Gobert, Delphine; Hamam, Bassam N; Thompson, Katherine M; Wu, Chia-Lun; Bouchard, Jean-François; Uetani, Noriko; Racine, Ronald J; Tremblay, Michel L; Ruthazer, Edward S; Chapman, C Andrew; Kennedy, Timothy E

    2012-07-01

    The mechanisms that regulate synapse formation and maintenance are incompletely understood. In particular, relatively few inhibitors of synapse formation have been identified. Receptor protein tyrosine phosphatase ? (RPTP?), a transmembrane tyrosine phosphatase, is widely expressed by neurons in developing and mature mammalian brain, and functions as a receptor for chondroitin sulfate proteoglycans that inhibits axon regeneration following injury. In this study, we address RPTP? function in the mature brain. We demonstrate increased axon collateral branching in the hippocampus of RPTP? null mice during normal aging or following chemically induced seizure, indicating that RPTP? maintains neural circuitry by inhibiting axonal branching. Previous studies demonstrated a role for pre-synaptic RPTP? promoting synaptic differentiation during development; however, subcellular fractionation revealed enrichment of RPTP? in post-synaptic densities. We report that neurons lacking RPTP? have an increased density of pre-synaptic varicosities in vitro and increased dendritic spine density and length in vivo. RPTP? knockouts exhibit an increased frequency of miniature excitatory post-synaptic currents, and greater paired-pulse facilitation, consistent with increased synapse density but reduced synaptic efficiency. Furthermore, RPTP? nulls exhibit reduced long-term potentiation and enhanced novel object recognition memory. We conclude that RPTP? limits synapse number and regulates synapse structure and function in the mature CNS. PMID:22519304

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

    ERIC Educational Resources Information Center

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

    2008-01-01

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

  13. Functional outcomes and quality of life in patients with brain tumors: A preliminary report

    Microsoft Academic Search

    Mark E. Huang; Jennifer E. Wartella; Jeffery S. Kreutzer

    2001-01-01

    Huang ME, Wartella JE, Kreutzer JS. Functional outcomes and quality of life in patients with brain tumors: a preliminary report. Arch Phys Med Rehabil 2001;82:1540-6. Objectives: To determine the relationship between functional outcome and quality of life (QOL) in patients with brain tumors receiving inpatient rehabilitation, and to assess the sensitivity of 4 assessment tools in measuring changes in that

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

    E-print Network

    Feng, Jianfeng

    2012-01-01

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

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

    E-print Network

    Washington at Seattle, University of

    An independent component analysis based tool for exploring functional connections in the brain S. M for investigating functional connectivity in the brain. Independent component analysis (ICA) is used as a measure of voxel similarity which allows the user to find and view statistically independent maps of correlated

  16. Selectionist models of perceptual and motor systems and implications for functionalist theories of brain function

    Microsoft Academic Search

    George N. Reeke; Olaf Sporns

    1990-01-01

    Functionalism is at present widely accepted as a working basis for cognitive science and artificial intelligence. This view holds that psychological phenomena can be adequately described in terms of functional processes carried out in the brain, and that these processes can be understood independently of the detailed structure and mode of development of the brain. In the functionalist view, the

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

    E-print Network

    Napadow, Vitaly

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

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

    Microsoft Academic Search

    Miguel A. L. Nicolelis

    2003-01-01

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

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

    ERIC Educational Resources Information Center

    Crafton, Robert E.; Kido, Elissa

    2000-01-01

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

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

    ERIC Educational Resources Information Center

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

    2006-01-01

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

  1. Functionally Enigmatic Genes: A Case Study of the Brain Ignorome

    PubMed Central

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

    2014-01-01

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

  2. Quaternary dynamics and plasticity underlie small heat shock protein chaperone function

    PubMed Central

    Stengel, Florian; Baldwin, Andrew J.; Painter, Alexander J.; Jaya, Nomalie; Basha, Eman; Kay, Lewis E.; Vierling, Elizabeth; Robinson, Carol V.; Benesch, Justin L. P.

    2010-01-01

    Small Heat Shock Proteins (sHSPs) are a diverse family of molecular chaperones that prevent protein aggregation by binding clients destabilized during cellular stress. Here we probe the architecture and dynamics of complexes formed between an oligomeric sHSP and client by employing unique mass spectrometry strategies. We observe over 300 different stoichiometries of interaction, demonstrating that an ensemble of structures underlies the protection these chaperones confer to unfolding clients. This astonishing heterogeneity not only makes the system quite distinct in behavior to ATP-dependent chaperones, but also renders it intractable by conventional structural biology approaches. We find that thermally regulated quaternary dynamics of the sHSP establish and maintain the plasticity of the system. This extends the paradigm that intrinsic dynamics are crucial to protein function to include equilibrium fluctuations in quaternary structure, and suggests they are integral to the sHSPs’ role in the cellular protein homeostasis network. PMID:20133845

  3. Brain potentials index executive functions during random number generation.

    PubMed

    Joppich, Gregor; Däuper, Jan; Dengler, Reinhard; Johannes, Sönke; Rodriguez-Fornells, Antoni; Münte, Thomas F

    2004-06-01

    The generation of random sequences is considered to tax different executive functions. To explore the involvement of these functions further, brain potentials were recorded in 16 healthy young adults while either engaging in random number generation (RNG) by pressing the number keys on a computer keyboard in a random sequence or in ordered number generation (ONG) necessitating key presses in the canonical order. Key presses were paced by an external auditory stimulus to yield either fast (1 press/800 ms) or slow (1 press/1300 ms) sequences in separate runs. Attentional demands of random and ordered tasks were assessed by the introduction of a secondary task (key-press to a target tone). The P3 amplitude to the target tone of this secondary task was reduced during RNG, reflecting the greater consumption of attentional resources during RNG. Moreover, RNG led to a left frontal negativity peaking 140 ms after the onset of the pacing stimulus, whenever the subjects produced a true random response. This negativity could be attributed to the left dorsolateral prefrontal cortex and was absent when numbers were repeated. This negativity was interpreted as an index for the inhibition of habitual responses. Finally, in response locked ERPs a negative component was apparent peaking about 50 ms after the key-press that was more prominent during RNG. Source localization suggested a medial frontal source. This effect was tentatively interpreted as a reflection of the greater monitoring demands during random sequence generation. PMID:15140558

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

    MedlinePLUS

    ... factors for age-related brain disorders may affect immune system function June 17, 2014 Scientists have discovered gene ... risk factors for age-related neurological disorders to immune system functions, such as inflammation, offers new insights into ...

  5. A Developmental Switch for Hebbian Plasticity

    PubMed Central

    Martens, Marijn B.; Celikel, Tansu; Tiesinga, Paul H. E.

    2015-01-01

    Hebbian forms of synaptic plasticity are required for the orderly development of sensory circuits in the brain and are powerful modulators of learning and memory in adulthood. During development, emergence of Hebbian plasticity leads to formation of functional circuits. By modeling the dynamics of neurotransmitter release during early postnatal cortical development we show that a developmentally regulated switch in vesicle exocytosis mode triggers associative (i.e. Hebbian) plasticity. Early in development spontaneous vesicle exocytosis (SVE), often considered as 'synaptic noise', is important for homogenization of synaptic weights and maintenance of synaptic weights in the appropriate dynamic range. Our results demonstrate that SVE has a permissive, whereas subsequent evoked vesicle exocytosis (EVE) has an instructive role in the expression of Hebbian plasticity. A timed onset for Hebbian plasticity can be achieved by switching from SVE to EVE and the balance between SVE and EVE can control the effective rate of Hebbian plasticity. We further show that this developmental switch in neurotransmitter release mode enables maturation of spike-timing dependent plasticity. A mis-timed or inadequate SVE to EVE switch may lead to malformation of brain networks thereby contributing to the etiology of neurodevelopmental disorders. PMID:26172394

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

    PubMed

    Tsunashima, Hitoshi; Yanagisawa, Kazuki

    2009-01-01

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

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

    PubMed Central

    Holschneider, DP; Maarek, J-M I

    2008-01-01

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

  8. Divide and Conquer: Functional Segregation of Synaptic Inputs by Astrocytic Microdomains Could Alleviate Paroxysmal Activity Following Brain Trauma

    PubMed Central

    Volman, Vladislav; Bazhenov, Maxim; Sejnowski, Terrence J.

    2013-01-01

    Traumatic brain injury often leads to epileptic seizures. Among other factors, homeostatic synaptic plasticity (HSP) mediates posttraumatic epileptogenesis through unbalanced synaptic scaling, partially compensating for the trauma-incurred loss of neural excitability. HSP is mediated in part by tumor necrosis factor alpha (TNF?), which is released locally from reactive astrocytes early after trauma in response to chronic neuronal inactivity. During this early period, TNF? is likely to be constrained to its glial sources; however, the contribution of glia-mediated spatially localized HSP to post-traumatic epileptogenesis remains poorly understood. We used computational model to investigate the reorganization of collective neural activity early after trauma. Trauma and synaptic scaling transformed asynchronous spiking into paroxysmal discharges. The rate of paroxysms could be reduced by functional segregation of synaptic input into astrocytic microdomains. Thus, we propose that trauma-triggered reactive gliosis could exert both beneficial and deleterious effects on neural activity. PMID:23357960

  9. Synaptic plasticity at the interface of health and disease: New insights on the role of endoplasmic reticulum intracellular calcium stores.

    PubMed

    Maggio, N; Vlachos, A

    2014-09-28

    Work from the past 40years has unraveled a wealth of information on the cellular and molecular mechanisms underlying synaptic plasticity and their relevance in physiological brain function. At the same time, it has been recognized that a broad range of neurological diseases may be accompanied by severe alterations in synaptic plasticity, i.e., 'maladaptive synaptic plasticity', which could initiate and sustain the remodeling of neuronal networks under pathological conditions. Nonetheless, our current knowledge on the specific contribution and interaction of distinct forms of synaptic plasticity (including metaplasticity and homeostatic plasticity) in the context of pathological brain states remains limited. This review focuses on recent experimental evidence, which highlights the fundamental role of endoplasmic reticulum-mediated Ca(2+) signals in modulating the duration, direction, extent and type of synaptic plasticity. We discuss the possibility that intracellular Ca(2+) stores may regulate synaptic plasticity and hence behavioral and cognitive functions at the interface between physiology and pathology. PMID:25264032

  10. Mismatch negativity, social cognition, and functional outcomes in patients after traumatic brain injury

    PubMed Central

    Sun, Hui-yan; Li, Qiang; Chen, Xi-ping; Tao, Lu-yang

    2015-01-01

    Mismatch negativity is generated automatically, and is an early monitoring indicator of neuronal integrity impairment and functional abnormality in patients with brain injury, leading to decline of cognitive function. Antipsychotic medication cannot affect mismatch negativity. The present study aimed to explore the relationships of mismatch negativity with neurocognition, daily life and social functional outcomes in patients after brain injury. Twelve patients with traumatic brain injury and 12 healthy controls were recruited in this study. We examined neurocognition with the Wechsler Adult Intelligence Scale-Revised China, and daily and social functional outcomes with the Activity of Daily Living Scale and Social Disability Screening Schedule, respectively. Mismatch negativity was analyzed from electroencephalogram recording. The results showed that mismatch negativity amplitudes decreased in patients with traumatic brain injury compared with healthy controls. Mismatch negativity amplitude was negatively correlated with measurements of neurocognition and positively correlated with functional outcomes in patients after traumatic brain injury. Further, the most significant positive correlations were found between mismatch negativity in the fronto-central region and measures of functional outcomes. The most significant positive correlations were also found between mismatch negativity at the FCz electrode and daily living function. Mismatch negativity amplitudes were extremely positively associated with Social Disability Screening Schedule scores at the Fz electrode in brain injury patients. These experimental findings suggest that mismatch negativity might efficiently reflect functional outcomes in patients after traumatic brain injury. PMID:26170824

  11. Thyroid hormone receptors in brain development and function

    Microsoft Academic Search

    Juan Bernal

    2007-01-01

    Thyroid hormones are important during development of the mammalian brain, acting on migration and differentiation of neural cells, synaptogenesis, and myelination. The actions of thyroid hormones are mediated through nuclear thyroid hormone receptors (TRs) and regulation of gene expression. The purpose of this article is to review the role of TRs in brain maturation. In developing humans maternal and fetal

  12. Gender differences in executive functions following traumatic brain injury

    Microsoft Academic Search

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

    2007-01-01

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

  13. Commentary: the future of forensic functional brain imaging.

    PubMed

    Langleben, Daniel D; Dattilio, Frank M

    2008-01-01

    In "Functional MRI Lie Detection: Too Good to be True?" in this issue of The Journal, Joseph Simpson reviews the merits and the limitations of using fMRI to detect deception. After presenting the gaps in experimental data that stand in the way of translating the laboratory proof of concept to a field application, Simpson surveys the legal, regulatory and ethics concerns facing fMRI, should it emerge as a technologically robust method of lie detection. In our commentary, we update and interpret the data described by Simpson, from the points of view of an experimental scientist and a forensic clinician. We conclude that the current research funding and literature are prematurely skewed toward discussion of existing findings, rather than generation of new fMRI data on deception and related topics such as mind-reading, consciousness, morality, and criminal responsibility. We propose that further progress in brain imaging research may foster the emergence of a new discipline of forensic MRI. PMID:19092068

  14. Astrocytes, Synapses and Brain Function: A Computational Approach

    NASA Astrophysics Data System (ADS)

    Nadkarni, Suhita

    2006-03-01

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

  15. CART in the brain of vertebrates: circuits, functions and evolution.

    PubMed

    Subhedar, Nishikant K; Nakhate, Kartik T; Upadhya, Manoj A; Kokare, Dadasaheb M

    2014-04-01

    Cocaine- and amphetamine-regulated transcript peptide (CART) with its wide distribution in the brain of mammals has been the focus of considerable research in recent years. Last two decades have witnessed a steady rise in the information on the genes that encode this neuropeptide and regulation of its transcription and translation. CART is highly enriched in the hypothalamic nuclei and its relevance to energy homeostasis and neuroendocrine control has been understood in great details. However, the occurrence of this peptide in a range of diverse circuitries for sensory, motor, vegetative, limbic and higher cortical areas has been confounding. Evidence that CART peptide may have role in addiction, pain, reward, learning and memory, cognition, sleep, reproduction and development, modulation of behavior and regulation of autonomic nervous system are accumulating, but an integration has been missing. A steady stream of papers has been pointing at the therapeutic potentials of CART. The current review is an attempt at piecing together the fragments of available information, and seeks meaning out of the CART elements in their anatomical niche. We try to put together the CART containing neuronal circuitries that have been conclusively demonstrated as well as those which have been proposed, but need confirmation. With a view to finding out the evolutionary antecedents, we visit the CART systems in sub-mammalian vertebrates and seek the answer why the system is shaped the way it is. We enquire into the conservation of the CART system and appreciate its functional diversity across the phyla. PMID:24468550

  16. Simulating ‘structure-function’ patterns of malignant brain tumors

    NASA Astrophysics Data System (ADS)

    Mansury, Yuri; Deisboeck, Thomas S.

    2004-01-01

    Rapid growth and extensive tissue infiltration are characteristics of highly malignant neuroepithelial brain tumors. Very little is known, however, about the existence of structure-function relationships in these types of neoplasm. Therefore, using a previously developed two-dimensional agent-based model, we have investigated the emergent patterns of multiple tumor cells that proliferate and migrate on an adaptive grid lattice, driven by a local-search mechanism and guided by the presence of distinct environmental conditions. Numerical results indicate a strong correlation between the fractal dimensions of the tumor surface and the average velocity of the tumor's spatial expansion. In particular, when the so called ‘beaten-path advantage’ intensifies, i.e., rising ‘mechanical rewards’ for cells to follow each other along preformed pathways, it results in an increase of the tumor system's fractal dimensions leading to a concomitant acceleration of its spatial expansion. Whereas cell migration is the dominant phenotype responsible for the more extensive branching patterns exhibiting higher fractal dimensions, cell proliferation appears to become more active primarily at lower fracticality associated with stronger mechanical confinements. Implications of these results for experimental and clinical cancer research are discussed.

  17. Age, plasticity, and equipotentiality: A reply to Smith

    Microsoft Academic Search

    Jack M. Fletcher; Paul Satz

    1983-01-01

    Responds to comments by A. Smith on the present authors' discussion of recovery of function from brain damage. It is argued that current interpretations of the literature on hemispherectomy and childhood aphasia are not consistent with Smith's viewpoints on age, plasticity, and equipotentiality. An evaluation of these concepts and the issues underlying recovery of function must be based on research

  18. Zinc: an underappreciated modulatory factor of brain function.

    PubMed

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

    2014-10-15

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

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

    SciTech Connect

    Aoyama, Hidefumi [Department of Radiology, Hokkaido University Graduate School of Medicine, Sapporo (Japan)]. E-mail: hao@radi.med.hokudai.ac.jp; Tago, Masao [Department of Radiology, University of Tokyo Hospital, Tokyo (Japan); Kato, Norio [Department of Radiology, Hokkaido University Graduate School of Medicine, Sapporo (Japan); Toyoda, Tatsuya [Department of Radiology, Kanto Medical Center Nippon Telegraph and Telephone East Corporation, Tokyo (Japan); Kenjyo, Masahiro [Department of Radiology, Hiroshima University School of Medicine, Hiroshima (Japan); Hirota, Saeko [Department of Radiology, Hyogo Medical Center for Adults, Akashi (Japan); Shioura, Hiroki [Department of Radiology, Izumisano General Hospital, Izumisano (Japan); Inomata, Taisuke [Department of Radiology, Osaka Medical College, Osaka (Japan); Kunieda, Etsuo [Department of Radiology, Keio University School of Medicine, Tokyo (Japan); Hayakawa, Kazushige [Department of Radiology, Kitasato University School of Medicine, Sagamihara (Japan); Nakagawa, Keiichi [Department of Radiology, University of Tokyo Hospital, Tokyo (Japan); Kobashi, Gen [Department of Global Health and Epidemiology, Division of Preventive Medicine, Hokkaido University Graduate School of Medicine, Sapporo (Japan); Shirato, Hiroki [Department of Radiology, Hokkaido University Graduate School of Medicine, Sapporo (Japan)

    2007-08-01

    Purpose: To determine how the omission of whole brain radiotherapy (WBRT) affects the neurocognitive function of patients with one to four brain metastases who have been treated with stereotactic radiosurgery (SRS). Methods and Materials: In a prospective randomized trial between WBRT+SRS and SRS alone for patients with one to four brain metastases, we assessed the neurocognitive function using the Mini-Mental State Examination (MMSE). Of the 132 enrolled patients, MMSE scores were available for 110. Results: In the baseline MMSE analyses, statistically significant differences were observed for total tumor volume, extent of tumor edema, age, and Karnofsky performance status. Of the 92 patients who underwent the follow-up MMSE, 39 had a baseline MMSE score of {<=}27 (17 in the WBRT+SRS group and 22 in the SRS-alone group). Improvements of {>=}3 points in the MMSEs of 9 WBRT+SRS patients and 11 SRS-alone patients (p = 0.85) were observed. Of the 82 patients with a baseline MMSE score of {>=}27 or whose baseline MMSE score was {<=}26 but had improved to {>=}27 after the initial brain treatment, the 12-, 24-, and 36-month actuarial free rate of the 3-point drop in the MMSE was 76.1%, 68.5%, and 14.7% in the WBRT+SRS group and 59.3%, 51.9%, and 51.9% in the SRS-alone group, respectively. The average duration until deterioration was 16.5 months in the WBRT+SRS group and 7.6 months in the SRS-alone group (p = 0.05). Conclusion: The results of the present study have revealed that, for most brain metastatic patients, control of the brain tumor is the most important factor for stabilizing neurocognitive function. However, the long-term adverse effects of WBRT on neurocognitive function might not be negligible.

  20. A novel brain partition highlights the modular skeleton shared by structure and function

    PubMed Central

    Diez, Ibai; Bonifazi, Paolo; Escudero, Iñaki; Mateos, Beatriz; Muñoz, Miguel A.; Stramaglia, Sebastiano; Cortes, Jesus M.

    2015-01-01

    Elucidating the intricate relationship between brain structure and function, both in healthy and pathological conditions, is a key challenge for modern neuroscience. Recent progress in neuroimaging has helped advance our understanding of this important issue, with diffusion images providing information about structural connectivity (SC) and functional magnetic resonance imaging shedding light on resting state functional connectivity (rsFC). Here, we adopt a systems approach, relying on modular hierarchical clustering, to study together SC and rsFC datasets gathered independently from healthy human subjects. Our novel approach allows us to find a common skeleton shared by structure and function from which a new, optimal, brain partition can be extracted. We describe the emerging common structure-function modules (SFMs) in detail and compare them with commonly employed anatomical or functional parcellations. Our results underline the strong correspondence between brain structure and resting-state dynamics as well as the emerging coherent organization of the human brain. PMID:26037235

  1. A novel brain partition highlights the modular skeleton shared by structure and function.

    PubMed

    Diez, Ibai; Bonifazi, Paolo; Escudero, Iñaki; Mateos, Beatriz; Muñoz, Miguel A; Stramaglia, Sebastiano; Cortes, Jesus M

    2015-01-01

    Elucidating the intricate relationship between brain structure and function, both in healthy and pathological conditions, is a key challenge for modern neuroscience. Recent progress in neuroimaging has helped advance our understanding of this important issue, with diffusion images providing information about structural connectivity (SC) and functional magnetic resonance imaging shedding light on resting state functional connectivity (rsFC). Here, we adopt a systems approach, relying on modular hierarchical clustering, to study together SC and rsFC datasets gathered independently from healthy human subjects. Our novel approach allows us to find a common skeleton shared by structure and function from which a new, optimal, brain partition can be extracted. We describe the emerging common structure-function modules (SFMs) in detail and compare them with commonly employed anatomical or functional parcellations. Our results underline the strong correspondence between brain structure and resting-state dynamics as well as the emerging coherent organization of the human brain. PMID:26037235

  2. Chemotherapy Altered Brain Functional Connectivity in Women with Breast Cancer: A Pilot Study

    PubMed Central

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

    2013-01-01

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

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

    Microsoft Academic Search

    Emmanuel S. Onaivi

    2006-01-01

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

  4. Emerging functions of myelin-associated proteins during development, neuronal plasticity, and neurodegeneration.

    PubMed

    Llorens, Franc; Gil, Vanessa; del Río, José Antonio

    2011-02-01

    Adult mammalian central nervous system (CNS) axons have a limited regrowth capacity following injury. Myelin-associated inhibitors (MAIs) limit axonal outgrowth, and their blockage improves the regeneration of damaged fiber tracts. Three of these proteins, Nogo-A, MAG, and OMgp, share two common neuronal receptors: NgR1, together with its coreceptors [p75(NTR), TROY, and Lingo-1]; and the recently described paired immunoglobulin-like receptor B (PirB). These proteins impair neuronal regeneration by limiting axonal sprouting. Some of the elements involved in the myelin inhibitory pathways may still be unknown, but the discovery that blocking both PirB and NgR1 activities leads to near-complete release from myelin inhibition, sheds light on one of the most competitive and intense fields of neuroregeneration study in recent decades. In parallel with the identification and characterization of the roles and functions of these inhibitory molecules in axonal regeneration, data gathered in the field strongly suggest that most of these proteins have roles other than axonal growth inhibition. The discovery of a new group of interacting partners for myelin-associated receptors and ligands, as well as functional studies within or outside the CNS environment, highlights the potential new physiological roles for these proteins in processes, such as development, neuronal homeostasis, plasticity, and neurodegeneration. PMID:21059749

  5. New Approaches for Studying Synaptic Development, Function, and Plasticity Using Drosophila as a Model System

    PubMed Central

    Frank, C. Andrew; Wang, Xinnan; Collins, Catherine A.; Rodal, Avital A.; Yuan, Quan; Verstreken, Patrik

    2013-01-01

    The fruit fly Drosophila melanogaster has been established as a premier experimental model system for neuroscience research. These organisms are genetically tractable, yet their nervous systems are sufficiently complex to study diverse processes that are conserved across metazoans, including neural cell fate determination and migration, axon guidance, synaptogenesis and function, behavioral neurogenetics, and responses to neuronal injury. For several decades, Drosophila neuroscientists have taken advantage of a vast toolkit of genetic and molecular techniques to reveal fundamental principles of neuroscience illuminating to all systems, including the first behavioral mutants from Seymour Benzer's pioneering work in the 1960s and 1970s, the cloning of the first potassium channel in the 1980s, and the identification of the core genes that orchestrate axon guidance and circadian rhythms in the 1990s. Over the past decade, new tools and innovations in genetic, imaging, and electrophysiological technologies have enabled the visualization, in vivo, of dynamic processes in synapses with unprecedented resolution. We will review some of the fresh insights into synaptic development, function, and plasticity that have recently emerged in Drosophila with an emphasis on the unique advantages of this model system. PMID:24198346

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

    PubMed Central

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

    2014-01-01

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

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

    PubMed

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

    2014-01-01

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

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

    PubMed Central

    Zheng, Weili; Ackley, Elena S.; Martínez-Ramón, Manel; Posse, Stefan

    2012-01-01

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

  9. Deep brain stimulation of the amygdala alleviates fear conditioning-induced alterations in synaptic plasticity in the cortical-amygdala pathway and fear memory.

    PubMed

    Sui, Li; Huang, SiJia; Peng, BinBin; Ren, Jie; Tian, FuYing; Wang, Yan

    2014-07-01

    Deep brain stimulation (DBS) of the amygdala has been demonstrated to modulate hyperactivity of the amygdala, which is responsible for the symptoms of post-traumatic stress disorder (PTSD), and thus might be used for the treatment of PTSD. However, the underlying mechanism of DBS of the amygdala in the modulation of the amygdala is unclear. The present study investigated the effects of DBS of the amygdala on synaptic transmission and synaptic plasticity at cortical inputs to the amygdala, which is critical for the formation and storage of auditory fear memories, and fear memories. The results demonstrated that auditory fear conditioning increased single-pulse-evoked field excitatory postsynaptic potentials in the cortical-amygdala pathway. Furthermore, auditory fear conditioning decreased the induction of paired-pulse facilitation and long-term potentiation, two neurophysiological models for studying short-term and long-term synaptic plasticity, respectively, in the cortical-amygdala pathway. In addition, all these auditory fear conditioning-induced changes could be reversed by DBS of the amygdala. DBS of the amygdala also rescued auditory fear conditioning-induced enhancement of long-term retention of fear memory. These findings suggested that DBS of the amygdala alleviating fear conditioning-induced alterations in synaptic plasticity in the cortical-amygdala pathway and fear memory may underlie the neuromodulatory role of DBS of the amygdala in activities of the amygdala. PMID:24610492

  10. A new macroscopically anisotropic pressure dependent yield function for metal matrix composite based on strain gradient plasticity for the microstructure

    NASA Astrophysics Data System (ADS)

    Azizi, Reza; Nyvang Legarth, Brian; Niordson, Christian F.

    2013-04-01

    Metal matrix composites with long aligned elastic fibers are studied using an energetic rate independent strain gradient plasticity theory with an isotropic pressure independent yield function at the microscale. The material response is homogenized to obtain a conventional macroscopic model that exhibits anisotropic yield properties with a pressure dependence. At the microscale free energy includes both elastic strains and plastic strain gradients, and the theory demands higher order boundary conditions in terms of plastic strain or work conjugate higher order tractions. The mechanical response is investigated numerically using a unit cell model with periodic boundary conditions containing a single fiber deformed under generalized plane strain conditions. The homogenized response can be modeled by conventional plasticity with an anisotropic yield surface and a free energy depending on plastic strain in addition to the elastic strain. Hill's classical anisotropic yield criterion is extended to cover the composite such that hydrostatic pressure dependency, Bauschinger stress and size-effects are considered. It is found that depending on the fiber volume fraction, the anisotropic yield surface of the composite is inclined compared to a standard pressure independent yield surfaces. The evolution of the macroscopic yield surface is investigated by quantifying both anisotropic hardening (expansion) and kinematic hardening (translation), where the coefficients of anisotropy and the Bauschinger stress are extracted.

  11. Effects of N-octyl lactate as plasticizer on the thermal and functional properties of extruded PLA-based films.

    PubMed

    Wang, Ya; Qin, Yuyue; Zhang, Yingjie; Yuan, Mingwei; Li, Hongli; Yuan, Minglong

    2014-06-01

    Films of poly(l-lactide) (PLA) plasticized with varying levels of N-octyl lactate (NOL) were prepared by extrusion. The thermal and functional properties of the blends were investigated by SEM, DSC, TGA, tensile, opacity, water vapor permeability, and water contact angle tests. The compatibility of the plasticizer with PLA was confirmed by DSC and SEM analysis. A higher plasticizing effect on the thermal properties of PLA was generally observed with the increase in NOL content. Additionally, the mechanical properties were improved with the increase in NOL content. The mechanical resistance of the films could be related to their glass transition temperature. The effect of the concentration of plasticizer on the opacity of the films was negligible. The water vapor permeability of the PLA/NOL composite films increased with the increase in the concentration of NOL; however, the values observed were still lower than the water vapor permeability of commercial LDPE films. In conclusion, the extruded PLA-based films with NOL plasticizers could be used as food-packaging materials. PMID:24598202

  12. A Brain-Wide Study of Age-Related Changes in Functional Connectivity.

    PubMed

    Geerligs, Linda; Renken, Remco J; Saliasi, Emi; Maurits, Natasha M; Lorist, Monicque M

    2015-07-01

    Aging affects functional connectivity between brain areas, however, a complete picture of how aging affects integration of information within and between functional networks is missing. We used complex network measures, derived from a brain-wide graph, to provide a comprehensive overview of age-related changes in functional connectivity. Functional connectivity in young and older participants was assessed during resting-state fMRI. The results show that aging has a large impact, not only on connectivity within functional networks but also on connectivity between the different functional networks in the brain. Brain networks in the elderly showed decreased modularity (less distinct functional networks) and decreased local efficiency. Connectivity decreased with age within networks supporting higher level cognitive functions, that is, within the default mode, cingulo-opercular and fronto-parietal control networks. Conversely, no changes in connectivity within the somatomotor and visual networks, networks implicated in primary information processing, were observed. Connectivity between these networks even increased with age. A brain-wide analysis approach of functional connectivity in the aging brain thus seems fundamental in understanding how age affects integration of information. PMID:24532319

  13. The structural-functional connectome and the default mode network of the human brain.

    PubMed

    Horn, Andreas; Ostwald, Dirk; Reisert, Marco; Blankenburg, Felix

    2014-11-15

    An emerging field of human brain imaging deals with the characterization of the connectome, a comprehensive global description of structural and functional connectivity within the human brain. However, the question of how functional and structural connectivity are related has not been fully answered yet. Here, we used different methods to estimate the connectivity between each voxel of the cerebral cortex based on functional magnetic resonance imaging (fMRI) and diffusion tensor imaging (DTI) data in order to obtain observer-independent functional-structural connectomes of the human brain. Probabilistic fiber-tracking and a novel global fiber-tracking technique were used to measure structural connectivity whereas for functional connectivity, full and partial correlations between each voxel pair's fMRI-timecourses were calculated. For every voxel, two vectors consisting of functional and structural connectivity estimates to all other voxels in the cortex were correlated with each other. In this way, voxels structurally and functionally connected to similar regions within the rest of the brain could be identified. Areas forming parts of the 'default mode network' (DMN) showed the highest agreement of structure-function connectivity. Bilateral precuneal and inferior parietal regions were found using all applied techniques, whereas the global tracking algorithm additionally revealed bilateral medial prefrontal cortices and early visual areas. There were no significant differences between the results obtained from full and partial correlations. Our data suggests that the DMN is the functional brain network, which uses the most direct structural connections. Thus, the anatomical profile of the brain seems to shape its functional repertoire and the computation of the whole-brain functional-structural connectome appears to be a valuable method to characterize global brain connectivity within and between populations. PMID:24099851

  14. Is There A Path Beyond BOLD? Molecular Imaging of Brain Function

    PubMed Central

    Koretsky, Alan P.

    2012-01-01

    The dependence of BOLD on neuro-vascular coupling leaves it steps removed from direct monitoring of neural function. MRI based approaches have been developed aimed at reporting more directly on brain function. These include: manganese enhanced MRI as a surrogate for calcium ion influx; agents responsive to calcium concentrations; approaches to measure membrane potential; agents to measure neurotransmittors; and strategies to measure gene expression. This work has led to clever design of molecular imaging tools and many contributions to studies of brain function in animal models. However, a robust approach that has potential to get MRI closer to neurons in the human brain has not yet emerged. PMID:22406355

  15. S-nitrosation and neuronal plasticity.

    PubMed

    Santos, A I; Martínez-Ruiz, A; Araújo, I M

    2015-03-01

    Nitric oxide (NO) has long been recognized as a multifaceted participant in brain physiology. Despite the knowledge that was gathered over many years regarding the contribution of NO to neuronal plasticity, for example the ability of the brain to change in response to new stimuli, only in recent years have we begun to understand how NO acts on the molecular and cellular level to orchestrate such important phenomena as synaptic plasticity (modification of the strength of existing synapses) or the formation of new synapses (synaptogenesis) and new neurons (neurogenesis). Post-translational modification of proteins by NO derivatives or reactive nitrogen species is a non-classical mechanism for signalling by NO. S-nitrosation is a reversible post-translational modification of thiol groups (mainly on cysteines) that may result in a change of function of the modified protein. S-nitrosation of key target proteins has emerged as a main regulatory mechanism by which NO can influence several levels of brain plasticity, which are reviewed in this work. Understanding how S-nitrosation contributes to neural plasticity can help us to better understand the physiology of these processes, and to better address pathological changes in plasticity that are involved in the pathophysiology of several neurological diseases. PMID:24962517

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

    E-print Network

    de Vries, Geert J.

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

  17. The Functional Organization of the Brain of the Cuttlefish Sepia officinalis

    Microsoft Academic Search

    B. B. Boycott

    1961-01-01

    The functional organization of the brain of Sepia has been investigated by electrical stimulation. As a result several new divisions of the brain have been made. The pedal ganglion has been shown to consist of four parts: (1) the anterior chromatophore lobes innervating the skin and muscles of the anterior part of the head and arms; (2) the anterior pedal

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

    E-print Network

    Boulanger, Lisa

    Scientists Probe Immune System's Role in Brain Function and Neurological Disease Bridget M. Kuehn E MERGING EVIDENCE SUGGESTS that proteins associated with the immune system may play additional roles protects the brain from the immune system by acting as a bar- ricade to its components, scientists have

  19. Hypertension and the Brain: Vulnerability of the Prefrontal Regions and Executive Functions

    Microsoft Academic Search

    Naftali Raz; Karen M. Rodrigue; James D. Acker

    2003-01-01

    Untreated hypertension negatively affects brain anatomy and cognitive functions, but the effects of medically treated hypertension are unclear. The authors compared 40 middle-age and older adults diagnosed with essential hypertension to demographically matched normotensive peers. Volumes of 7 brain regions and deep and periventricular white-matter hyperintensities (WMH) were measured on magnetic resonance imaging scans. Performance in 4 cognitive domains (perseveration,

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

    E-print Network

    Tian, Jie

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

  1. Image-Derived Input Function for Human Brain Using High Resolution PET Imaging with [11

    E-print Network

    Shen, Jun

    Image-Derived Input Function for Human Brain Using High Resolution PET Imaging with [11 C was to test seven previously published image-input methods in state-of-the-art high resolution PET brain images. Images were obtained with a High Resolution Research Tomograph plus a resolution

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

    Microsoft Academic Search

    Bruce S. McEwen

    2008-01-01

    Early life experiences have powerful effects on the brain and body lasting throughout the entire life span and influencing brain function, behavior, and the risk for a number of systemic and mental disorders. Animal models of early life adversity are providing mechanistic insights, including glimpses into the fascinating world that is now called “epigenetics” as well as the role of

  3. The social brain in adolescence: Evidence from functional magnetic resonance imaging and behavioural studies

    Microsoft Academic Search

    Stephanie Burnett; Catherine Sebastian; Kathrin Cohen Kadosh; Sarah-Jayne Blakemore

    2011-01-01

    Social cognition is the collection of cognitive processes required to understand and interact with others. The term ‘social brain’ refers to the network of brain regions that underlies these processes. Recent evidence suggests that a number of social cognitive functions continue to develop during adolescence, resulting in age differences in tasks that assess cognitive domains including face processing, mental state

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

    ERIC Educational Resources Information Center

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

    2003-01-01

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

  5. Arrested neuronal proliferation and impaired hippocampal function following fractionated brain irradiation in the adult rat

    Microsoft Academic Search

    T. M Madsen; P. E. G Kristjansen; T. G Bolwig; G Wörtwein

    2003-01-01

    The generation of new neurons in the adult mammalian brain has been documented in numerous recent reports. Studies undertaken so far indicate that adult hippocampal neurogenesis is related in a number of ways to hippocampal function.Here, we report that subjecting adult rats to fractionated brain irradiation blocked the formation of new neurons in the dentate gyrus of the hippocampus. At

  6. Horticultural Therapy has Beneficial Effects on Brain Functions in Cerebrovascular Diseases

    Microsoft Academic Search

    Yuko Mizuno-Matsumoto; Syoji Kobashi; Yutaka Hata; Osamu Ishikawa; Fusayo Asano

    2008-01-01

    Horticultural therapy (HT) is gaining attention as a form of rehabilitations in medical fields especially such as occupational therapy and nursing care, although its effectiveness has not been proven yet. This paper uses a strictly medical point of view to assess whether or not HT is effective for improvement of functional activities in the brains of brain-damaged patients. Five patients

  7. Structural and functional brain development and its relation to cognitive development

    Microsoft Academic Search

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

    2000-01-01

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

  8. Nociception-induced spatial and temporal plasticity of synaptic connection and function in the hippocampal formation of rats: a multi-electrode array recording

    Microsoft Academic Search

    Xiao-Yan Zhao; Ming-Gang Liu; Dong-Liang Yuan; Yan Wang; Ying He; Dan-Dan Wang; Xue-Feng Chen; Fu-Kang Zhang; Hua Li; Xiao-Sheng He; Jun Chen

    2009-01-01

    BACKGROUND: Pain is known to be processed by a complex neural network (neuromatrix) in the brain. It is hypothesized that under pathological state, persistent or chronic pain can affect various higher brain functions through ascending pathways, leading to co-morbidities or mental disability of pain. However, so far the influences of pathological pain on the higher brain functions are less clear

  9. Microglia function during brain development: New insights from animal models.

    PubMed

    Bilimoria, Parizad M; Stevens, Beth

    2015-08-18

    The role of microglia in healthy brains is just beginning to receive notice. Recent studies have revealed that these phagocytic cells control the patterning and wiring of the developing central nervous system (CNS) by regulating, amongst many other processes, programmed cell death, activity-dependent synaptic pruning and synapse maturation. Microglia also play important roles in the mature brain and have demonstrated effects on behavior. Converging evidence from human and mouse studies together raise questions as to the role of microglia in disorders of brain development such as autism and, schizophrenia. In this review, we summarize a number of major findings regarding the role of microglia in brain development and highlight some key questions and avenues for future study. This article is part of a Special Issue entitled SI: Neuroimmunology in Health And Disease. PMID:25463024

  10. Neuron-glia metabolic coupling and plasticity.

    PubMed

    Magistretti, Pierre J

    2006-06-01

    The coupling between synaptic activity and glucose utilization (neurometabolic coupling) is a central physiological principle of brain function that has provided the basis for 2-deoxyglucose-based functional imaging with positron emission tomography (PET). Astrocytes play a central role in neurometabolic coupling, and the basic mechanism involves glutamate-stimulated aerobic glycolysis; the sodium-coupled reuptake of glutamate by astrocytes and the ensuing activation of the Na-K-ATPase triggers glucose uptake and processing via glycolysis, resulting in the release of lactate from astrocytes. Lactate can then contribute to the activity-dependent fuelling of the neuronal energy demands associated with synaptic transmission. An operational model, the 'astrocyte-neuron lactate shuttle', is supported experimentally by a large body of evidence, which provides a molecular and cellular basis for interpreting data obtained from functional brain imaging studies. In addition, this neuron-glia metabolic coupling undergoes plastic adaptations in parallel with adaptive mechanisms that characterize synaptic plasticity. Thus, distinct subregions of the hippocampus are metabolically active at different time points during spatial learning tasks, suggesting that a type of metabolic plasticity, involving by definition neuron-glia coupling, occurs during learning. In addition, marked variations in the expression of genes involved in glial glycogen metabolism are observed during the sleep-wake cycle, with in particular a marked induction of expression of the gene encoding for protein targeting to glycogen (PTG) following sleep deprivation. These data suggest that glial metabolic plasticity is likely to be concomitant with synaptic plasticity. PMID:16731806

  11. 2D He+ pickup ion velocity distribution functions: STEREO PLASTIC observations

    NASA Astrophysics Data System (ADS)

    Drews, C.; Berger, L.; Taut, A.; Peleikis, T.; Wimmer-Schweingruber, R. F.

    2015-03-01

    Context. He+ pickup ions are either born from the ionization of interstellar neutral helium inside our heliosphere, the so-called interstellar pickup ions, or through the interaction of solar wind ions with small dust particles, the so-called inner source of pickup ions. Until now, most observations of pickup ions were limited to reduced 1D velocity spectra, which are insufficient to study certain characteristics of the He+ velocity distribution function (VDF). Aims: It is generally assumed that rapid pitch-angle scattering of freshly created pickup ions quickly leads to a fully isotropic He+ VDF. In light of recent observations, this assumption has found to be oversimplified and needs to be reinvestigated. Methods: Using He+ pickup ion data from the PLASTIC instrument on board the STEREO A spacecraft, we reconstruct a reduced form of the He+ VDF in two dimensions. This allows us to study relative changes of the 2D He+ VDF as a function of the configuration of the heliospheric magnetic field. Results: Our observations show that the He+ VDF is highly anisotropic and even indicates that, at least for certain configurations of B, it is not fully gyrotropic. Our results further suggest, that the observed velocity and pitch angle of He+ depends strongly on the local solar magnetic field vector, B, the ecliptic longitude, ?, the solar wind speed, vsw, and the global distribution of B. Conclusions: We found two distinct signatures that systematically change as a function of the alignment of B: (1) a ring beam distribution that is most pronounced at wsw> 0.5 and likely attributed to interstellar He+; (2) a beam signature aligned parallel to B that is most pronounced at wsw < 0.5 and attributed to inner-source He+. The strong anisotropy and the aforementioned dependencies of the He+ VDF also imply that observations of 1D velocity spectra of He+ pickup ions are potentially deceiving.

  12. Obesity Increases Cerebrocortical Reactive Oxygen Species And Impairs Brain Function

    PubMed Central

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

    2014-01-01

    Nearly two-thirds of the population in the United States is overweight or obese, and this unprecedented level of obesity will undoubtedly have a profound impact on overall health, although little is currently known about the effects of obesity on the brain. The objective of the current study was to investigate cerebral oxidative stress and cognitive decline in the context of diet-induced obesity (DIO). We demonstrate for the first time that DIO induces higher levels of reactive oxygen species (ROS) in the brain, and promotes cognitive impairment. Importantly, we also demonstrate for the first time in these studies that both body weight and adiposity are tightly correlated with the level of ROS. Interestingly, ROS were not correlated with cognitive decline in this model. Alterations in the antioxidant/detoxification Nrf2 pathway, superoxide dismutase, and catalase were not significantly altered in response to DIO. A significant impairment in glutathione peroxidase was observed in response to DIO. Taken together, these data demonstrate for the first time that DIO increases the level of total and individual ROS in the brain, and highlight a direct relationship between the amount of adiposity and the level of oxidative stress within the brain. These data have important implications for understanding the negative effects of obesity on the brain, and are vital to understanding the role of oxidative stress in mediating the effects of obesity on the brain. PMID:23116605

  13. Functional brain imaging in 14 patients with dissociative amnesia reveals right inferolateral prefrontal hypometabolism.

    PubMed

    Brand, Matthias; Eggers, Carsten; Reinhold, Nadine; Fujiwara, Esther; Kessler, Josef; Heiss, Wolf-Dieter; Markowitsch, Hans J

    2009-10-30

    Dissociative amnesia is a condition usually characterized by severely impaired retrograde memory functioning in the absence of structural brain damage. Recent case studies nevertheless found functional brain changes in patients suffering from autobiographical-episodic memory loss in the cause of dissociative amnesia. Functional changes were demonstrated in both resting state and memory retrieval conditions. In addition, some but not all cases also showed other neuropsychological impairments beyond retrograde memory deficits. However, there is no group study available that examined potential functional brain abnormalities and accompanying neuropsychological deteriorations in larger samples of patients with dissociative retrograde amnesia. We report functional imaging and neuropsychological data acquired in 14 patients with dissociative amnesia following stressful or traumatic events. All patients suffered from autobiographical memory loss. In addition, approximately half of the patients had deficits in anterograde memory and executive functioning. Accompanying functional brain changes were measured by [18F]fluorodeoxyglucose positron emission tomography (FDG-PET). Regional glucose utilization of the patients was compared with that of 19 healthy subjects, matched for age and gender. We found significantly decreased glucose utilization in the right inferolateral prefrontal cortex in the patients. Hypometabolism in this brain region, known to be involved in retrieval of autobiographical memories and self-referential processing, may be a functional brain correlate of dissociative amnesia. PMID:19783409

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

    PubMed Central

    Liu, Xiao; Duyn, Jeff H.

    2013-01-01

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

  15. Lynx1, a cholinergic brake limits plasticity in adult visual cortex

    PubMed Central

    Morishita, Hirofumi; Miwa, Julie M.; Heintz, Nathaniel; Hensch, Takao K

    2012-01-01

    Experience-dependent brain plasticity typically declines after an early critical period during which circuits are established. Loss of plasticity with closure of the critical period limits improvement of function in adulthood, but the mechanisms that change the brain’s plasticity remain poorly understood. Here, we identified an increase in expression of Lynx1 protein in mice that prevented plasticity in the primary visual cortex late in life. Removal of this molecular brake enhanced nicotinic acetylcholine receptor signaling. Lynx1 expression thus maintains stability of mature cortical networks in the presence of cholinergic innervation. The results suggest that modulating the balance between excitatory and inhibitory circuits reactivates visual plasticity and may present a therapeutic target. PMID:21071629

  16. The role of plasticity-related functional reorganization in the explanation of central dyslexias.

    PubMed

    Welbourne, Stephen R; Woollams, Anna M; Crisp, Jenni; Ralph, Matthew A Lambon

    2011-03-01

    This investigation explored the hypothesis that patterns of acquired dyslexia may reflect, in part, plasticity-driven relearning that dynamically alters the division of labour (DOL) between the direct, orthography ? phonology (O ? P) pathway and the semantically mediated, orthography ? semantics ? phonology (O ? S ? P) pathway. Three simulations were conducted using a variant of the triangle model of reading. The model demonstrated core characteristics of normal reading behaviour in its undamaged state. When damage was followed by reoptimization (mimicking spontaneous recovery), the model reproduced the deficits observed in the central dyslexias-acute phonological damage combined with recovery matched data taken from a series of 12 phonological dyslexic patients-whilst progressive semantic damage interspersed with recovery reproduced data taken from 100 observations of semantic dementia patients. The severely phonologically damaged model also produced symptoms of deep dyslexia (imageability effects, production of semantic and mixed semantic/visual errors). In all cases, the DOL changed significantly in the recovery period, suggesting that postmorbid functional reorganization is important in understanding behaviour in chronic-stage patients. PMID:22122115

  17. Establishing, versus Maintaining, Brain Function: A Neuro-computational Model of Cortical Reorganization after Injury to the Immature Brain

    E-print Network

    Varier, Sreedevi; Forsyth, Rob; 10.1017/S1355617711000993

    2011-01-01

    The effect of age at injury on outcome after acquired brain injury (ABI) has been the subject of much debate. Many argue that young brains are relatively tolerant of injury. A contrasting viewpoint due to Hebb argues that greater system integrity may be required for the initial establishment of a function than for preservation of an already-established function. A neuro-computational model of cortical map formation was adapted to examine effects of focal and distributed injury at various stages of development. This neural network model requires a period of training during which it self-organizes to establish cortical maps. Injuries were simulated by lesioning the model at various stages of this process and network function was monitored as "development" progressed to completion. Lesion effects are greater for larger, earlier, and distributed (multifocal) lesions. The mature system is relatively robust, particularly to focal injury. Activities in recovering systems injured at an early stage show changes that e...

  18. A multimodal approach for determining brain networks by jointly modeling functional and structural connectivity.

    PubMed

    Xue, Wenqiong; Bowman, F DuBois; Pileggi, Anthony V; Mayer, Andrew R

    2015-01-01

    Recent innovations in neuroimaging technology have provided opportunities for researchers to investigate connectivity in the human brain by examining the anatomical circuitry as well as functional relationships between brain regions. Existing statistical approaches for connectivity generally examine resting-state or task-related functional connectivity (FC) between brain regions or separately examine structural linkages. As a means to determine brain networks, we present a unified Bayesian framework for analyzing FC utilizing the knowledge of associated structural connections, which extends an approach by Patel et al. (2006a) that considers only functional data. We introduce an FC measure that rests upon assessments of functional coherence between regional brain activity identified from functional magnetic resonance imaging (fMRI) data. Our structural connectivity (SC) information is drawn from diffusion tensor imaging (DTI) data, which is used to quantify probabilities of SC between brain regions. We formulate a prior distribution for FC that depends upon the probability of SC between brain regions, with this dependence adhering to structural-functional links revealed by our fMRI and DTI data. We further characterize the functional hierarchy of functionally connected brain regions by defining an ascendancy measure that compares the marginal probabilities of elevated activity between regions. In addition, we describe topological properties of the network, which is composed of connected region pairs, by performing graph theoretic analyses. We demonstrate the use of our Bayesian model using fMRI and DTI data from a study of auditory processing. We further illustrate the advantages of our method by comparisons to methods that only incorporate functional information. PMID:25750621

  19. Reduction of Endogenous Kynurenic Acid Formation Enhances Extracellular Glutamate, Hippocampal Plasticity, and Cognitive Behavior

    Microsoft Academic Search

    Michelle C Potter; Greg I Elmer; Richard Bergeron; Edson X Albuquerque; Paolo Guidetti; Hui-Qiu Wu; Robert Schwarcz

    2010-01-01

    At endogenous brain concentrations, the astrocyte-derived metabolite kynurenic acid (KYNA) antagonizes the ?7 nicotinic acetylcholine receptor and, possibly, the glycine co-agonist site of the NMDA receptor. The functions of these two receptors, which are intimately involved in synaptic plasticity and cognitive processes, may, therefore, be enhanced by reductions in brain KYNA levels. This concept was tested in mice with a

  20. Long-Term Exercise Is Needed to Enhance Synaptic Plasticity in the Hippocampus

    ERIC Educational Resources Information Center

    Patten, Anna R.; Sickmann, Helle; Hryciw, Brett N.; Kucharsky, Tessa; Parton, Roberta; Kernick, Aimee; Christie, Brian R.

    2013-01-01

    Exercise can have many benefits for the body, but it also benefits the brain by increasing neurogenesis, synaptic plasticity, and performance on learning and memory tasks. The period of exercise needed to realize the structural and functional benefits for the brain have not been well delineated, and previous studies have used periods of exercise…

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

    PubMed Central

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

    2010-01-01

    The blood-brain barrier (BBB) maintains brain homeostasis and limits the entry of toxins and pathogens into the brain. Despite its importance, little is known about the molecular mechanisms regulating the development and function of this crucial barrier. In this study we have developed methods to highly purify and gene profile endothelial cells from different tissues, and by comparing the transcriptional profile of brain endothelial cells with those purified from the liver and lung, we have generated a comprehensive resource of transcripts that are enriched in the BBB forming endothelial cells of the brain. Through this comparison we have identified novel tight junction proteins, transporters, metabolic enzymes, signaling components, and unknown transcripts whose expression is enriched in central nervous system (CNS) endothelial cells. This analysis has identified that RXRalpha signaling cascade is specifically enriched at the BBB, implicating this pathway in regulating this vital barrier. This dataset provides a resource for understanding CNS endothelial cells and their interaction with neural and hematogenous cells. PMID:21060791

  2. Group 1 Metabotropic Glutamate Receptor Function and Its Regulation of Learning and Memory in the Aging Brain

    PubMed Central

    Ménard, Caroline; Quirion, Rémi

    2012-01-01

    Normal aging is generally characterized by a slow decline of cognitive abilities albeit with marked individual differences. Several animal models have been studied to explore the molecular and cellular mechanisms underlying this phenomenon. The excitatory neurotransmitter glutamate and its receptors have been closely linked to spatial learning and hippocampus-dependent memory processes. For decades, ionotropic glutamate receptors have been known to play a critical role in synaptic plasticity, a form of adaptation regulating memory formation. Over the past 10?years, several groups have shown the importance of group 1 metabotropic glutamate receptor (mGluR) in successful cognitive aging. These G-protein-coupled receptors are enriched in the hippocampal formation and interact physically with other proteins in the membrane including glutamate ionotropic receptors. Synaptic plasticity is crucial to maintain cognitive abilities and long-term depression (LTD) induced by group 1 mGluR activation, which has been linked to memory in the aging brain. The translation and synthesis of proteins by mGluR-LTD modulate ionotropic receptor trafficking and expression of immediate early genes related to cognition. Fragile X syndrome, a genetic form of autism characterized by memory deficits, has been associated to mGluR receptor malfunction and aberrant activation of its downstream signaling pathways. Dysfunction of mGluR could also be involved in neurodegenerative disorders like Alzheimer’s disease (AD). Indeed, beta-amyloid, the main component of insoluble senile plaques and one of the hallmarks of AD, occludes mGluR-dependent LTD leading to diminished functional synapses. This review highlights recent findings regarding mGluR signaling, related synaptic plasticity, and their potential involvement in normal aging and neurological disorders. PMID:23091460

  3. CONEUR-1155; NO. OF PAGES 12 Please cite this article in press as: Barrett LF, Satpute AB. Large-scale brain networks in affective and social neuroscience: towards an integrative functional architecture of the brain, Curr Opin

    E-print Network

    Barrett, Lisa Feldman

    to distinct brain net- works. Understanding the functions of the human brain in psychological terms requires-scale brain networks in affective and social neuroscience: towards an integrative functional architecture of the brain, Curr Opin Neurobiol (2013), http://dx.doi.org/10.1016/j.conb.2012.12.012 Large-scale brain

  4. Impairment in long-term memory formation and learning-dependent synaptic plasticity in mice lacking glycogen synthase in the brain.

    PubMed

    Duran, Jordi; Saez, Isabel; Gruart, Agnès; Guinovart, Joan J; Delgado-García, José M

    2013-04-01

    Glycogen is the only carbohydrate reserve of the brain, but its overall contribution to brain functions remains unclear. Although it has traditionally been considered as an emergency energetic reservoir, increasing evidence points to a role of glycogen in the normal activity of the brain. To address this long-standing question, we generated a brain-specific Glycogen Synthase knockout (GYS1(Nestin-KO)) mouse and studied the functional consequences of the lack of glycogen in the brain under alert behaving conditions. These animals showed a significant deficiency in the acquisition of an associative learning task and in the concomitant activity-dependent changes in hippocampal synaptic strength. Long-term potentiation (LTP) evoked in the hippocampal CA3-CA1 synapse was also decreased in behaving GYS1(Nestin-KO) mice. These results unequivocally show a key role of brain glycogen in the proper acquisition of new motor and cognitive abilities and in the underlying changes in synaptic strength. PMID:23281428

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

    PubMed

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

    2015-03-01

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

  6. Intersubject Variability of and Genetic Effects on the Brain's Functional Connectivity during Infancy

    PubMed Central

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

    2014-01-01

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

  7. Small-World Brain Network and Dynamic Functional Distribution in Patients with Subcortical Vascular Cognitive Impairment.

    PubMed

    Yu, Yongqiang; Zhou, Xia; Wang, Haibao; Hu, Xiaopeng; Zhu, Xiaoqun; Xu, Liyan; Zhang, Chao; Sun, Zhongwu

    2015-01-01

    To investigate the topological properties of the functional connectivity and their relationships with cognition impairment in subcortical vascular cognitive impairment (SVCI) patients, resting-state fMRI and graph theory approaches were employed in 23 SVCI patients and 20 healthy controls. Functional connectivity between 90 brain regions was estimated using bivariate correlation analysis and thresholded to construct a set of undirected graphs. Moreover, all of them were subjected to a battery of cognitive assessment, and the correlations between graph metrics and cognitive performance were further analyzed. Our results are as follows: functional brain networks of both SVCI patients and controls showed small-world attributes over a range of thresholds(0.15?sparsity?0.40). However, global topological organization of the functional brain networks in SVCI was significantly disrupted, as indicated by reduced global and local efficiency, clustering coefficients and increased characteristic path lengths relative to normal subjects. The decreased activity areas in SVCI predominantly targeted in the frontal-temporal lobes, while subcortical regions showed increased topological properties, which are suspected to compensate for the inefficiency of the functional network. We also demonstrated that altered brain network properties in SVCI are closely correlated with general cognitive and praxis dysfunction. The disruption of whole-brain topological organization of the functional connectome provides insight into the functional changes in the human brain in SVCI. PMID:26132397

  8. Small-World Brain Network and Dynamic Functional Distribution in Patients with Subcortical Vascular Cognitive Impairment

    PubMed Central

    Yu, Yongqiang; Zhou, Xia; Wang, Haibao; Hu, Xiaopeng; Zhu, Xiaoqun; Xu, Liyan; Zhang, Chao; Sun, Zhongwu

    2015-01-01

    To investigate the topological properties of the functional connectivity and their relationships with cognition impairment in subcortical vascular cognitive impairment (SVCI) patients, resting-state fMRI and graph theory approaches were employed in 23 SVCI patients and 20 healthy controls. Functional connectivity between 90 brain regions was estimated using bivariate correlation analysis and thresholded to construct a set of undirected graphs. Moreover, all of them were subjected to a battery of cognitive assessment, and the correlations between graph metrics and cognitive performance were further analyzed. Our results are as follows: functional brain networks of both SVCI patients and controls showed small-world attributes over a range of thresholds(0.15?sparsity?0.40). However, global topological organization of the functional brain networks in SVCI was significantly disrupted, as indicated by reduced global and local efficiency, clustering coefficients and increased characteristic path lengths relative to normal subjects. The decreased activity areas in SVCI predominantly targeted in the frontal-temporal lobes, while subcortical regions showed increased topological properties, which are suspected to compensate for the inefficiency of the functional network. We also demonstrated that altered brain network properties in SVCI are closely correlated with general cognitive and praxis dysfunction. The disruption of whole-brain topological organization of the functional connectome provides insight into the functional changes in the human brain in SVCI. PMID:26132397

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

    PubMed Central

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

    2012-01-01

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

  10. Categories and functional units: An infinite hierarchical model for brain activations

    E-print Network

    Lashkari, Danial

    We present a model that describes the structure in the responses of different brain areas to a set of stimuli in terms of stimulus categories (clusters of stimuli) and functional units (clusters of voxels). We assume that ...

  11. Brain functional magnetic resonance imaging response to glucose and fructose infusions in humans

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Objective: In animals, intracerebroventricular glucose and fructose have opposing effects on appetite and weight regulation. In humans, functional brain magnetic resonance imaging (fMRI) studies during carbohydrate ingestion suggest that glucose may regulate HT signaling but are potentially confoun...

  12. Functional Magnetic Resonance Imaging of Rats with Experimental Autoimmune Encephalomyelitis Reveals Brain Cortex Remodelling

    E-print Network

    Tambalo, Stefano; Peruzzotti-Jametti, Luca; Rigolio, Roberta; Fiorini, Silvia; Bontempi, Pietro; Mallucci, Giulia; Balzarotti, Beatrice; Marmiroli, Paola; Sbarbati, Andrea; Cavaletti, Guido; Pluchino, Stefano; Marzola, Pasquina

    2015-01-01

    reorganization and its brain structural/pathological correlates in Dark Agouti rats with experimental autoimmune encephalomyelitis (EAE), a widely accepted preclinical model of chronic MS. Morphological and functional MRI (fMRI) were performed before disease...

  13. A Probabilistic Model of Functional Brain Connectivity Network for Discovering Novel Biomarkers

    PubMed Central

    Bian, Jiang; Xie, Mengjun; Topaloglu, Umit; Cisler, Josh M.

    2013-01-01

    Graph theoretical analyses of functional brain connectivity networks have been limited to a static view of brain activities over the entire timeseries. In this paper, we propose a new probabilistic model of the functional brain connectivity network, the strong-edge model, which incorporates the temporal fluctuation of neurodynamics. We also introduce a systematic approach to identifying biomarkers based on network characteristics that quantitatively describe the organization of the brain network. The evaluation results of the proposed strong-edge network model is quite promising. The biomarkers derived from the strong-edge model have achieved much higher prediction accuracy of 89% (ROCAUC: 0.96) in distinguishing depression subjects from healthy controls in comparison with the conventional network model (accuracy: 76%, ROC-AUC: 0.87). These novel biomarkers have the high potential of being applied clinically in diagnosing neurological and psychiatric brain diseases with noninvasive neuroimaging technologies. PMID:24303289

  14. Brain temperature fluctuation: a reflection of functional neural activation.

    PubMed

    Kiyatkin, Eugene A; Brown, P Leon; Wise, Roy A

    2002-07-01

    Although it is known that relatively large increases in local brain temperature can occur during behaviour and in response to various novel, stressful and emotionally arousing environmental stimuli, the source of this heat is not clearly established. To clarify this issue, we monitored the temperature in three brain structures (dorsal and ventral striatum, cerebellum) and in arterial blood at the level of the abdominal aorta in freely moving rats exposed to several environmental challenges ranging from traditional stressors to simple sensory stimuli (cage change, tail pinch, exposure to another male rat, a female rat, a mouse or an unexpected sound). We found that brain temperature was consistently higher than arterial blood temperature, and that brain temperature increased prior to, and to a greater extent than, the increase in blood temperature evoked by each test challenge. Thus, the local metabolic consequences of widely correlated neural activity appear to be the primary source of increases in brain temperature and a driving force behind the associated changes in body temperature. PMID:12153543

  15. Reduced brain insulin-like growth factor I function during aging

    Microsoft Academic Search

    Alexandre Pastoris Muller; Ana M. Fernandez; Clarissa Haas; Eduardo Zimmer; Luis Valmor Portela; Ignacio Torres-Aleman

    Peripheral insulin-like growth factor I (IGF-I) function progressively deteriorates with age. However, whereas deterioration of IGF-I function in the aged brain seems probable, it has not been directly addressed yet. Because serum IGF-I can enter into the brain through the cerebrospinal fluid (CSF), we examined this route of entrance in aged mice. To distinguish endogenous murine IGF-I from exogenously applied

  16. Local brain atrophy accounts for functional activity differences in normal aging

    Microsoft Academic Search

    Grégoria Kalpouzos; Jonas Persson; Lars Nyberg

    Functional brain imaging studies of normal aging typically show age-related under- and overactivations during episodic memory tasks. Older individuals also undergo nonuniform gray matter volume (GMv) loss. Thus, age differences in functional brain activity could at least in part result from local atrophy. We conducted a series of voxel-based blood oxygen level-dependent (BOLD)-GMv analyses to highlight whether age-related under- and

  17. Erythropoietin promotes neurovascular remodeling and long-term functional recovery in rats following traumatic brain injury

    Microsoft Academic Search

    Ruizhuo Ning; Ye Xiong; Asim Mahmood; Yanlu Zhang; Yuling Meng; Changsheng Qu; Michael Chopp

    2011-01-01

    Erythropoietin (EPO) improves functional recovery after traumatic brain injury (TBI). This study was designed to investigate long-term (3months) effects of EPO on brain remodeling and functional recovery in rats after TBI. Young male Wistar rats were subjected to unilateral controlled cortical impact injury. TBI rats were divided into the following groups: (1) saline group (n=7); (2) EPO-6h group (n=8); and

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

    NASA Astrophysics Data System (ADS)

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

    2014-03-01

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

  19. The use of functional and effective connectivity techniques to understand the developing brain.

    PubMed

    Goldenberg, Diane; Galván, Adriana

    2015-04-01

    Developmental neuroscience, the study of the processes that shape and reshape the maturing brain, is a growing field still in its nascent stages. The developmental application of functional and effective connectivity techniques, which are tools that measure the interactions between elements of the brain, has revealed insight to the developing brain as a complex system. However, this insight is granted in discrete windows of consecutive time. The current review uses dynamic systems theory as a conceptual framework to understand how functional and effective connectivity tools may be used in conjunction to capture the dynamic process of change that occurs with development. PMID:25770766

  20. The role of Polo-like kinase 2 in synaptic function and plasticity

    E-print Network

    Seeburg, Daniel P. (Daniel Philip)

    2007-01-01

    Homeostatic forms of plasticity keep the spiking output of neurons within an optimal range in the face of changing activity levels of the surrounding network, but little is known about the underlying molecular mechanisms, ...

  1. Plastic changes underlying vestibular compensation in the guinea-pig persist in isolated, in vitro whole brain preparations

    Microsoft Academic Search

    N Vibert; A Babalian; M Serafin; J.-P Gasc; M Mühlethaler; P.-P Vidal

    1999-01-01

    Vestibular compensation for the postural and oculomotor deficits induced by unilateral labyrinthectomy is a model of post-lesional plasticity in the central nervous system. Just after the removal of one labyrinth, the deafferented, ipsilateral vestibular nucleus neurons are almost silent, and the discharge of the contralateral vestibular nucleus neurons is increased. The associated static disorders disappear in a few days, as

  2. Polysialic acid–neural cell adhesion molecule in brain plasticity: From synapses to integration of new neurons

    Microsoft Academic Search

    Eduardo Gascon; Laszlo Vutskits; Jozsef Zoltan Kiss

    2007-01-01

    Isoforms of the neuronal cell adhesion molecule (NCAM) carrying the linear homopolymer of alpha 2,8-linked sialic acid (polysialic acid, PSA) have emerged as particularly attractive candidates for promoting plasticity in the nervous system. The large negatively charged PSA chain of NCAM is postulated to be a spacer that reduces adhesion forces between cells allowing dynamic changes in membrane contacts. Accumulating

  3. Neurogenesis, Cellular Plasticity and Cognition: The Impact of Stem Cells in the Adult and Aging Brain – A Mini-Review

    Microsoft Academic Search

    Sebastien Couillard-Despres; Bernhard Iglseder; Ludwig Aigner

    2011-01-01

    The hippocampus is a structure equipped with a high degree of flexibility and adaptation. In contrast to most structures of the adult central nervous system, the hippocampus can rely on a form of plasticity known as neurogenesis. The continuous provision of new neurons derived from resident adult neural stem cells appears to facilitate the execution of hippocampal-dependent tasks since reduction

  4. The degree to which genes and environment determine brain structure and function is of fundamental importance. Large-

    E-print Network

    Thompson, Paul

    significantly influenced cortical structure in Broca's and Wernicke's language areas, as well as frontal brainThe degree to which genes and environment determine brain structure and function is of fundamental-specific patterns of gene and brain function in large human populations1,2. Yet, little is known about the genetic

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

    E-print Network

    Deco, Gustavo

    aspects and understand how dynamics and structure interact to form functional brain net- works in task connectivity patterns, and given support to the view that the brain works at a critical point at the edgeReview Bottom up modeling of the connectome: Linking structure and function in the resting brain

  6. Functional brain activation to emotional and nonemotional faces in healthy children: Evidence for developmentally

    E-print Network

    for developmentally undifferentiated amygdala function during the school-age period David Pagliaccio & Joan L. Luby of the amygdala's functional role in humans consistently noted that the amygdala is significantly involvedFunctional brain activation to emotional and nonemotional faces in healthy children: Evidence

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

    Microsoft Academic Search

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

    2002-01-01

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

  8. Dipeptidyl peptidase 4 inhibitor improves brain insulin sensitivity, but fails to prevent cognitive impairment in orchiectomy obese rats.

    PubMed

    Pintana, Hiranya; Pongkan, Wanpitak; Pratchayasakul, Wasana; Chattipakorn, Nipon; Chattipakorn, Siriporn C

    2015-08-01

    It is unclear whether the dipeptidyl peptidase 4 (DPP4) inhibitor can counteract brain insulin resistance, brain mitochondrial dysfunction, impairment of hippocampal synaptic plasticity and cognitive decline in testosterone-deprived obese rats. We hypothesized that DPP4 inhibitor vildagliptin improves cognitive function in testosterone-deprived obese rats by restoring brain insulin sensitivity, brain mitochondrial function and hippocampal synaptic plasticity. Thirty male Wistar rats received either a sham-operated (S, n=6) or bilateral orchiectomy (ORX, n=24). ORX rats were divided into two groups and fed with either a normal diet (ND (NDO)) or a high-fat diet (HFO) for 12 weeks. Then, ORX rats in each dietary group were divided into two subgroups (n=6/subgroup) to receive either a vehicle or vildagliptin (3?mg/kg per day, p.o.) for 4 weeks. After treatment, cognitive function, metabolic parameters, brain insulin sensitivity, hippocampal synaptic plasticity and brain mitochondrial function were determined in each rat. We found that HFO rats exhibited peripheral and brain insulin resistance, brain mitochondrial dysfunction, impaired hippocampal synaptic plasticity and cognitive decline. NDO rats did not develop peripheral and brain insulin resistance. However, impaired hippocampal synaptic plasticity and cognitive decline occurred. Vildagliptin significantly improved peripheral insulin sensitivity, restored brain insulin sensitivity and decreased brain mitochondrial reactive oxygen species production in HFO rats. However, vildagliptin did not restore hippocampal synaptic plasticity and cognitive function in both NDO and HFO rats. These findings suggest that vildagliptin could not counteract the impairment of hippocampal synaptic plasticity and cognitive decline in testosterone-deprived subjects, despite its effects on improved peripheral and brain insulin sensitivity as well as brain mitochondrial function. PMID:26016746

  9. Impairment of Glymphatic Pathway Function Promotes Tau Pathology after Traumatic Brain Injury

    PubMed Central

    Chen, Michael J.; Plog, Benjamin A.; Zeppenfeld, Douglas M.; Soltero, Melissa; Yang, Lijun; Singh, Itender; Deane, Rashid; Nedergaard, Maiken

    2014-01-01

    Traumatic brain injury (TBI) is an established risk factor for the early development of dementia, including Alzheimer's disease, and the post-traumatic brain frequently exhibits neurofibrillary tangles comprised of aggregates of the protein tau. We have recently defined a brain-wide network of paravascular channels, termed the “glymphatic” pathway, along which CSF moves into and through the brain parenchyma, facilitating the clearance of interstitial solutes, including amyloid-?, from the brain. Here we demonstrate in mice that extracellular tau is cleared from the brain along these paravascular pathways. After TBI, glymphatic pathway function was reduced by ?60%, with this impairment persisting for at least 1 month post injury. Genetic knock-out of the gene encoding the astroglial water channel aquaporin-4, which is importantly involved in paravascular interstitial solute clearance, exacerbated glymphatic pathway dysfunction after TBI and promoted the development of neurofibrillary pathology and neurodegeneration in the post-traumatic brain. These findings suggest that chronic impairment of glymphatic pathway function after TBI may be a key factor that renders the post-traumatic brain vulnerable to tau aggregation and the onset of neurodegeneration. PMID:25471560

  10. Dietary resistant starch improves selected brain and behavioral functions in adult and aged rodents.

    PubMed

    Zhou, June; Keenan, Michael J; Fernandez-Kim, Sun Ok; Pistell, Paul J; Ingram, Donald K; Li, Bing; Raggio, Anne M; Shen, Li; Zhang, Hanjie; McCutcheon, Kathleen L; Tulley, Richard T; Blackman, Marc R; Keller, Jeffrey N; Martin, Roy J

    2013-11-01

    Resistant starch (RS) is a dietary fiber that exerts multiple beneficial effects. The current study explored the effects of dietary RS on selected brain and behavioral functions in adult and aged rodents. Because glucokinase (GK) expression in hypothalamic arcuate nucleus and area postrema of the brainstem is important for brain glucose sensing, GK mRNA was measured by brain nuclei microdissection and PCR. Adult RS-fed rats had a higher GK mRNA than controls in both brain nuclei, an indicator of improved brain glucose sensing. Next, we tested whether dietary RS improve selected behaviors in aged mice. RS-fed aged mice exhibited (i) an increased eating responses to fasting, a behavioral indicator of improvement in aged brain glucose sensing; (ii) a longer latency to fall from an accelerating rotarod, a behavioral indicator of improved motor coordination; and (iii) a higher serum active glucagon-like peptide-1 (GLP-1). Then, GLP-1 receptor null (GLP-1RKO) mice were used to test the role of GLP-1 in brain glucose sensing, and they exhibited impaired eating responses to fasting. We conclude that in rodents (i) dietary RS improves two important indicators of brain function: glucose sensing and motor coordination, and (ii) GLP-1 is important in the optimal feeding response to a fast. PMID:23818307

  11. Call for startup project applications `brain function and dysfunction' The University Research Profile Area Brain Function and Dysfunction over the Lifespan invites

    E-print Network

    Galis, Frietson

    Call for startup project applications `brain function and dysfunction' The University Research startup projects. This is the first call with a submission deadline on November 1, 2010. Three projects will be selected. A second and third call will follow in 2011 and 2012. The goal of these startup projects

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

    E-print Network

    Hintz et al, Real-time neonatal optical functional brain imaging 335 J. Perinat. Med. Bedside Biomedical Optics Group, Division of Neonatal and Developmental Medicine, Stanford University School, these modalities are not feasible in many intensive care situations due to the problems and hazards of moving

  13. Melanoma Spheroids Grown Under Neural Crest Cell Conditions Are Highly Plastic Migratory\\/Invasive Tumor Cells Endowed with Immunomodulator Function

    Microsoft Academic Search

    Kiran Ramgolam; Jessica Lauriol; Claude Lalou; Laura Lauden; Laurence Michel; Abdel-Majid Khatib; Fawzi Aoudjit; Dominique Charron; Catherine Alcaide-Loridan; Reem; Pierre de la Grange

    2011-01-01

    Background: The aggressiveness of melanoma tumors is likely to rely on their well-recognized heterogeneity and plasticity. Melanoma comprises multi-subpopulations of cancer cells some of which may possess stem cell-like properties. Although useful, the sphere-formation assay to identify stem cell-like or tumor initiating cell subpopulations in melanoma has been challenged, and it is unclear if this model can predict a functional

  14. Diagnosing and managing functional visual complications after brain injury

    Microsoft Academic Search

    Christine L. Allison; Helen Gabriel; Darrell Schlange

    2008-01-01

    BackgroundBrain injury caused by an arteriovenous malformation (AVM) hemorrhage is an uncommon occurrence in a teenager. An AVM is a congenital anomaly of unknown etiology, often described as a tangle of arteries and veins that may vary in length and width leading to a loss of capillary bed. The vessels can break down with time and cause hemorrhage or aneurysm.

  15. The blood–brain barrier and immune function and dysfunction

    Microsoft Academic Search

    William A. Banks; Michelle A. Erickson

    2010-01-01

    The blood–brain barrier (BBB) is the monocellular interface that divides the peripheral circulation from direct contact with the central nervous system (CNS). This interface consists of several parallel barriers that include most notably the capillary bed of the CNS and the choroid plexus. These barriers at one level create the dichotomy between the circulating factors of the immune system and

  16. N -Acetylaspartate in the Vertebrate Brain: Metabolism and Function

    Microsoft Academic Search

    Morris H. Baslow

    2003-01-01

    N-Acetyl-l-aspartate (NAA) is an amino acid that is present in the vertebrate brain. Its concentration is one of the highest of all free amino acids and, although NAA is synthesized and stored primarily in neurons, it cannot be hydrolyzed in these cells. Furthermore, neuronal NAA is dynamic and turns over more than once each day by virtue of its continuous

  17. Noninvasive Functional Imaging of Human Brain Using Light

    Microsoft Academic Search

    David A. Benaron; Susan R. Hintz; Arno Villringer; David Boas; Andreas Kleinschmidt; Jens Frahm; Christina Hirth; Hellmuth Obrig; John C. van Houten; Eben L. Kermit; Wai-Fung Cheong; David K. Stevenson

    2000-01-01

    Analysis of photon transit time for low-power light passing into the head, and through both skull and brain, of human subjects allowed for tomographic imaging of cerebral hemoglobin oxygenation based on photon diffusion theory. In healthy adults, imaging of changes in hemoglobin saturation during hand movement revealed focal, contralateral increases in motor cortex oxygenation with spatial agreement to activation maps

  18. Toward Technical Understanding. Part 1: Brain Structure and Function.

    ERIC Educational Resources Information Center

    Haile, J. M.

    1997-01-01

    Argues that there are many kinds of understanding and many ways to reach these different understandings. Suggests that this is the reason why articulating general rules that can consistently lead to understanding is difficult. Discusses the relationship between brain structure and learning. (DDR)

  19. Critical Periods of Brain Growth and Cognitive Function in Children

    ERIC Educational Resources Information Center

    Gale, Catharine R.; O'Callaghan, Finbar J.; Godfrey, Keith M.; Law, Catherine M.; Martyn, Christopher N.

    2004-01-01

    There is evidence that IQ tends to be higher in those who were heavier at birth or who grew taller in childhood and adolescence. Although these findings imply that growth in both foetal and postnatal life influences cognitive performance, little is known about the relative importance of brain growth during different periods of development. We…

  20. Abstract: Voltage sensitive Ca2+ channels in brain functions

    E-print Network

    Gruen, Sonja

    to restore the resting Ca2+ level. We use various tools for analysis of the mutants to define the brain link, sleep stability, and pathogenesis of absence seizures. We are interested in trying to understand how+ channels. Science 302:117-119 Lee J et al. (2004). Lack of delta waves and sleep disturbances during NREM

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

    PubMed Central

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

    2014-01-01

    With the advent of neuroimaging techniques, it becomes feasible to explore the structure-function relationships in the brain. When the brain is not involved in any cognitive task or stimulated by any external output, it preserves important activities which follow well-defined spatial distribution patterns. Understanding the self-organization of the brain from its anatomical structure, it has been recently suggested to model the observed functional pattern from the structure of white matter fiber bundles. Different models which study synchronization (e.g., the Kuramoto model) or global dynamics (e.g., the Ising model) have shown success in capturing fundamental properties of the brain. In particular, these models can explain the competition between modularity and specialization and the need for integration in the brain. Graphing the functional and structural brain organization supports the model and can also highlight the strategy used to process and organize large amount of information traveling between the different modules. How the flow of information can be prevented or partially destroyed in pathological states, like in severe brain injured patients with disorders of consciousness or by pharmacological induction like in anaesthesia, will also help us to better understand how global or integrated behavior can emerge from local and modular interactions. PMID:25276772

  2. Deficits in cognitive function and hippocampal plasticity in GM2/GD2 synthase knockout mice.

    PubMed

    Sha, Sha; Zhou, Libin; Yin, Jun; Takamiya, Koga; Furukawa, Keiko; Furukawa, Koichi; Sokabe, Masahiro; Chen, Ling

    2014-04-01

    In this study, we used GM2/GD2 synthase knockout (GM2/GD2?/?) mice to examine the influence of deficiency in ganglioside “a-pathway” and “b-pathway” on cognitive performances and hippocampal synaptic plasticity. Eight-week-old GM2/GD2?/? male mice showed a longer escape-latency in Morris water maze test and a shorter latency in step-down inhibitory avoidance task than wild-type (WT) mice. Schaffer collateral-CA1 synapses in the hippocampal slices from GM2/GD2?/? mice showed an increase in the slope of EPSPs with reduced paired-pulse facilitation, indicating an enhancement of their presynaptic glutamate release. In GM2/GD2?/? mice, NMDA receptor (NMDAr)-dependent LTP could not be induced by high-frequency (100–200 Hz) tetanus or ?-burst conditioning stimulation (CS), whereas NMDAr-independent LTP was induced by medium-frequency CS (20–50 Hz). The application of mono-sialoganglioside GM1 in the slice from GM2/GD2?/? mice, to specifically recover the a-pathway, prevented the increased presynaptic glutamate release and 20 Hz-LTP induction, whereas it could not rescue the impaired NMDAr-dependent LTP. These findings suggest that b-pathway deficiency impairs cognitive function probably through suppression of NMDAr-dependent LTP, while a-pathway deficiency may facilitate NMDAr-independent LTP through enhancing presynaptic glutamate release. As both of the NMDAr-independent LTP and increased presynaptic glutamate release were sensitive to the blockade of L-type voltage-gated Ca2+ channels (L-VGCC), a-pathway deficiency may affect presynaptic L-VGCC. PMID:24765676

  3. Plasticity of in vitro-generated urothelial cells for functional tissue formation.

    PubMed

    Wezel, Felix; Pearson, Joanna; Southgate, Jennifer

    2014-05-01

    Tissue-engineering and regenerative medicine strategies for the bladder and urinary tract are dependent on the ability to generate adequate numbers of differentiation-competent uro-epithelial cells. In situ, urothelium is a mitotically quiescent, but highly regenerative epithelium. Although evidence supports a resident, basally located urothelial progenitor population, no specific stem cell has been identified. Our aim was to isolate basal and suprabasal urothelial subpopulations and characterize their regenerative and differentiation potentials in vitro. We showed that the low-affinity nerve growth factor receptor (NGFR) is a cell surface-expressed marker that is restricted to basal cells in normal human and porcine urothelia in situ. We used NGFR immunoseparation and differential adherence to collagen to isolate subpopulations of urothelial cells for culture. Isolated basal-derived porcine NGFR? urothelial cells initially showed a higher proliferative and clonogenic phenotype than their suprabasal NGFR? counterparts in vitro. However, after a short period of adaptation to culture, both NGFR? and NGFR? subpopulations became indistinguishable and displayed similar long-term growth and differentiation potentials. Both populations generated hierarchically organized, differentiated tissue equivalents similar to native urothelium, including a fully reconstituted NGFR? basal cell layer by the NGFR? suprabasal-derived population. Similarly, slow collagen-adherent human urothelial cells initially displayed a longer lag phase than rapid-adherent cultures, but after adaptation, both populations showed similar long-term proliferation, exponential growth rates, and capacity to form a functional barrier urothelium. Our results support a model where urothelial cell phenotype is plastic and determined by the niche or local environment. This has direct implications for tissue-engineering strategies requiring urothelial cell expansion and provides a new perspective toward understanding urothelial regeneration and differentiated tissue hierarchy. PMID:24350594

  4. Using Brain-Computer Interfaces to Induce Neural Plasticity and Restore Function

    E-print Network

    Jegelka, Stefanie

    T¨ubingen, Germany Donatella Mattia Clinical Neurophysiology, Neuroelectrical Imaging and BCI Lab states, including but not limited to those affected by stroke, epilepsy, ADHD, chronic pain, Parkinson's disease, schizophrenia, or anxiety disorders. Unfortunately, for most patient groups empirical evidence

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

    ERIC Educational Resources Information Center

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

    2010-01-01

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

  6. A New Model for Determining the Influence of Age and Sex on Functional Recovery following Hypoxic-Ischemic Brain Damage

    Microsoft Academic Search

    Jerome Y. Yager; Sandra Wright; Edward A. Armstrong; Cleo M. Jahraus; Deborah M. Saucier

    2005-01-01

    Stroke is a disorder affecting the lives of all age groups, and particularly those at the opposite ends of the age spectrum. It is generally believed that the immature brain is more resistant to damage resulting from a hypoxic\\/ischemic injury, and that it is also more ‘plastic’ in terms of its ability to recover. Evidence from our laboratory, and a

  7. Functional brain connectivity using fMRI in aging and Alzheimer's disease.

    PubMed

    Dennis, Emily L; Thompson, Paul M

    2014-03-01

    Normal aging and Alzheimer's disease (AD) cause profound changes in the brain's structure and function. AD in particular is accompanied by widespread cortical neuronal loss, and loss of connections between brain systems. This degeneration of neural pathways disrupts the functional coherence of brain activation. Recent innovations in brain imaging have detected characteristic disruptions in functional networks. Here we review studies examining changes in functional connectivity, measured through fMRI (functional magnetic resonance imaging), starting with healthy aging and then Alzheimer's disease. We cover studies that employ the three primary methods to analyze functional connectivity--seed-based, ICA (independent components analysis), and graph theory. At the end we include a brief discussion of other methodologies, such as EEG (electroencephalography), MEG (magnetoencephalography), and PET (positron emission tomography). We also describe multi-modal studies that combine rsfMRI (resting state fMRI) with PET imaging, as well as studies examining the effects of medications. Overall, connectivity and network integrity appear to decrease in healthy aging, but this decrease is accelerated in AD, with specific systems hit hardest, such as the default mode network (DMN). Functional connectivity is a relatively new topic of research, but it holds great promise in revealing how brain network dynamics change across the lifespan and in disease. PMID:24562737

  8. Handedness- and brain size-related efficiency differences in small-world brain networks: a resting-state functional magnetic resonance imaging study.

    PubMed

    Li, Meiling; Wang, Junping; Liu, Feng; Chen, Heng; Lu, Fengmei; Wu, Guorong; Yu, Chunshui; Chen, Huafu

    2015-05-01

    The human brain has been described as a complex network, which integrates information with high efficiency. However, the relationships between the efficiency of human brain functional networks and handedness and brain size remain unclear. Twenty-one left-handed and 32 right-handed healthy subjects underwent a resting-state functional magnetic resonance imaging scan. The whole brain functional networks were constructed by thresholding Pearson correlation matrices of 90 cortical and subcortical regions. Graph theory-based methods were employed to further analyze their topological properties. As expected, all participants demonstrated small-world topology, suggesting a highly efficient topological structure. Furthermore, we found that smaller brains showed higher local efficiency, whereas larger brains showed higher global efficiency, reflecting a suitable efficiency balance between local specialization and global integration of brain functional activity. Compared with right-handers, significant alterations in nodal efficiency were revealed in left-handers, involving the anterior and median cingulate gyrus, middle temporal gyrus, angular gyrus, and amygdala. Our findings indicated that the functional network organization in the human brain was associated with handedness and brain size. PMID:25535788

  9. Plastics in Building.

    ERIC Educational Resources Information Center

    Skeist, Irving, Ed.

    The evaluation and use of plastics in the construction industry are explained. The contributors offer extensive, timely, and thoroughly researched data on the chemistry, properties, functions, engineering behavior, and specific applications of plastics to building requirements. The major subjects discussed in depth are--(1) the role of plastics in…

  10. Functional brain connectivity from EEG in epilepsy: seizure prediction and epileptogenic focus localization.

    PubMed

    van Mierlo, Pieter; Papadopoulou, Margarita; Carrette, Evelien; Boon, Paul; Vandenberghe, Stefaan; Vonck, Kristl; Marinazzo, Daniele

    2014-10-01

    Today, neuroimaging techniques are frequently used to investigate the integration of functionally specialized brain regions in a network. Functional connectivity, which quantifies the statistical dependencies among the dynamics of simultaneously recorded signals, allows to infer the dynamical interactions of segregated brain regions. In this review we discuss how the functional connectivity patterns obtained from intracranial and scalp electroencephalographic (EEG) recordings reveal information about the dynamics of the epileptic brain and can be used to predict upcoming seizures and to localize the seizure onset zone. The added value of extracting information that is not visibly identifiable in the EEG data using functional connectivity analysis is stressed. Despite the fact that many studies have showed promising results, we must conclude that functional connectivity analysis has not made its way into clinical practice yet. PMID:25014528

  11. Functional optoacoustic neuro-tomography (FONT) for whole-brain monitoring of calcium indicators

    E-print Network

    Sela, Gali; Deán-Ben, X Luís; Kneipp, Moritz; Ntziachristos, Vasilis; Shoham, Shy; Westmeyer, Gil G; Razansky, Daniel

    2015-01-01

    Non-invasive observation of spatiotemporal neural activity of large neural populations distributed over entire brains is a longstanding goal of neuroscience. We developed a real-time volumetric and multispectral optoacoustic tomography platform for imaging of neural activation deep in scattering brains. The system can record 100 volumetric frames per second across a 200mm3 field of view and spatial resolutions below 70um. Experiments performed in immobilized and freely swimming larvae and in adult zebrafish brains demonstrate, for the first time, the fundamental ability to optoacoustically track neural calcium dynamics in animals labeled with genetically encoded calcium indicator GCaMP5G, while overcoming the longstanding penetration barrier of optical imaging in scattering brains. The newly developed platform offers unprecedented capabilities for functional whole-brain observations of fast calcium dynamics; in combination with optoacoustics' well-established capacity in resolving vascular hemodynamics, it co...

  12. Functional Dopaminergic Neurons in Substantia Nigra are Required for Transcranial Magnetic Stimulation-Induced Motor Plasticity.

    PubMed

    Hsieh, Tsung-Hsun; Huang, Ying-Zu; Rotenberg, Alexander; Pascual-Leone, Alvaro; Chiang, Yung-Hsiao; Wang, Jia-Yi; Chen, Jia-Jin J

    2015-07-01

    Repetitive magnetic stimulation (rTMS), including theta burst stimulation (TBS), is capable of modulating motor cortical excitability through plasticity-like mechanisms and might have therapeutic potential for Parkinson's disease (PD). An animal model would be helpful for elucidating the mechanism of rTMS that remain unclear and controversial. Here, we have established a TMS model in rat and applied this model to study the impact of substantia nigra dopamine neuron on TBS-induced motor plasticity in PD rats. In parallel with human results, continuous TBS (cTBS) successfully suppressed motor evoked potentials (MEPs), while MEPs increased after intermittent TBS (iTBS) in healthy rats. We then tested the effect of iTBS in early and advanced 6-hydroxydopamine (6-OHDA)-lesioned PD. Moreover, dopaminergic neurons in substantia nigra and rotation behavior were assessed to correlate with the amount of iTBS-induced plasticity. In results, iTBS-induced potentiation was reduced in early PD rats and was absent in advanced PD rats. Such reduction in plasticity strongly correlated with the dopaminergic cell loss and the count of rotation in PD rats. In conclusion, we have established a TMS PD rat model. With the help of this model, we confirmed the loss of domaninergic neurons in substantia nigra resulting in reduced rTMS-induced motor plasticity in PD. PMID:24451657

  13. The Formation of Multi-synaptic Connections by the Interaction of Synaptic and Structural Plasticity and Their Functional Consequences

    PubMed Central

    Fauth, Michael; Wörgötter, Florentin; Tetzlaff, Christian

    2015-01-01

    Cortical connectivity emerges from the permanent interaction between neuronal activity and synaptic as well as structural plasticity. An important experimentally observed feature of this connectivity is the distribution of the number of synapses from one neuron to another, which has been measured in several cortical layers. All of these distributions are bimodal with one peak at zero and a second one at a small number (3–8) of synapses. In this study, using a probabilistic model of structural plasticity, which depends on the synaptic weights, we explore how these distributions can emerge and which functional consequences they have. We find that bimodal distributions arise generically from the interaction of structural plasticity with synaptic plasticity rules that fulfill the following biological realistic constraints: First, the synaptic weights have to grow with the postsynaptic activity. Second, this growth curve and/or the input-output relation of the postsynaptic neuron have to change sub-linearly (negative curvature). As most neurons show such input-output-relations, these constraints can be fulfilled by many biological reasonable systems. Given such a system, we show that the different activities, which can explain the layer-specific distributions, correspond to experimentally observed activities. Considering these activities as working point of the system and varying the pre- or postsynaptic stimulation reveals a hysteresis in the number of synapses. As a consequence of this, the connectivity between two neurons can be controlled by activity but is also safeguarded against overly fast changes. These results indicate that the complex dynamics between activity and plasticity will, already between a pair of neurons, induce a variety of possible stable synaptic distributions, which could support memory mechanisms. PMID:25590330

  14. Resting State Brain Function Analysis Using Concurrent BOLD in ASL Perfusion fMRI

    PubMed Central

    Zhu, Senhua; Fang, Zhuo; Hu, Siyuan; Wang, Ze; Rao, Hengyi

    2013-01-01

    The past decade has seen astounding discoveries about resting-state brain activity patterns in normal brain as well as their alterations in brain diseases. While the vast majority of resting-state studies are based on the blood-oxygen-level-dependent (BOLD) functional MRI (fMRI), arterial spin labeling (ASL) perfusion fMRI can simultaneously capture BOLD and cerebral blood flow (CBF) signals, providing a unique opportunity for assessing resting brain functions with concurrent BOLD (ccBOLD) and CBF signals. Before taking that benefit, it is necessary to validate the utility of ccBOLD signal for resting-state analysis using conventional BOLD (cvBOLD) signal acquired without ASL modulations. To address this technical issue, resting cvBOLD and ASL perfusion MRI were acquired from a large cohort (n?=?89) of healthy subjects. Four widely used resting-state brain function analyses were conducted and compared between the two types of BOLD signal, including the posterior cingulate cortex (PCC) seed-based functional connectivity (FC) analysis, independent component analysis (ICA), analysis of amplitude of low frequency fluctuation (ALFF), and analysis of regional homogeneity (ReHo). Consistent default mode network (DMN) as well as other resting-state networks (RSNs) were observed from cvBOLD and ccBOLD using PCC-FC analysis and ICA. ALFF from both modalities were the same for most of brain regions but were different in peripheral regions suffering from the susceptibility gradients induced signal drop. ReHo showed difference in many brain regions, likely reflecting the SNR and resolution differences between the two BOLD modalities. The DMN and auditory networks showed highest CBF values among all RSNs. These results demonstrated the feasibility of ASL perfusion MRI for assessing resting brain functions using its concurrent BOLD in addition to CBF signal, which provides a potentially useful way to maximize the utility of ASL perfusion MRI. PMID:23750275

  15. Intrinsic Functional Brain Architecture Derived from Graph Theoretical Analysis in the Human Fetus

    PubMed Central

    Thomason, Moriah E.; Brown, Jesse A.; Dassanayake, Maya T.; Shastri, Rupal; Marusak, Hilary A.; Hernandez-Andrade, Edgar; Yeo, Lami; Mody, Swati; Berman, Susan; Hassan, Sonia S.; Romero, Roberto

    2014-01-01

    The human brain undergoes dramatic maturational changes during late stages of fetal and early postnatal life. The importance of this period to the establishment of healthy neural connectivity is apparent in the high incidence of neural injury in preterm infants, in whom untimely exposure to ex-uterine factors interrupts neural connectivity. Though the relevance of this period to human neuroscience is apparent, little is known about functional neural networks in human fetal life. Here, we apply graph theoretical analysis to examine human fetal brain connectivity. Utilizing resting state functional magnetic resonance imaging (fMRI) data from 33 healthy human fetuses, 19 to 39 weeks gestational age (GA), our analyses reveal that the human fetal brain has modular organization and modules overlap functional systems observed postnatally. Age-related differences between younger (GA <31 weeks) and older (GA?31 weeks) fetuses demonstrate that brain modularity decreases, and connectivity of the posterior cingulate to other brain networks becomes more negative, with advancing GA. By mimicking functional principles observed postnatally, these results support early emerging capacity for information processing in the human fetal brain. Current technical limitations, as well as the potential for fetal fMRI to one day produce major discoveries about fetal origins or antecedents of neural injury or disease are discussed. PMID:24788455

  16. Functional imaging of the brain by infrared radiation (thermoencephaloscopy)

    Microsoft Academic Search

    Igor A. Shevelev

    1998-01-01

    A technique for thermal imaging of the animal and human brain cortex using an infrared optical system is described. Thermoencephaloscopy (TES) is based on improved thermovision and image processing techniques and allows two-dimensional, contact-free, dynamic and non-invasive recording of background and evoked cortical activity through an unopened skull. Activated (heated) and deactivated (cooled) zones of the cerebral cortex are revealed.

  17. Functional Magnetic Resonance-Guided Brain Tumor Resection

    Microsoft Academic Search

    Peter D. Kim; Charles L. Truwit; Walter A. Hall

    \\u000a The ultimate goal of brain tumor surgery is maximum tumor removal without the development of a new neurologic deficit. This\\u000a is especially true in the treatment of intraparenchymal tumors such as gliomas and metastatic lesions. In the treatment of\\u000a glioblastoma multiforme (GBM), for example, gross total resection (GTR) has been demonstrated in a number of studies to be\\u000a one of

  18. Temporal and Functional Relationship of Brain Maturation and Behavioural Development

    Microsoft Academic Search

    H. R. GÜttinger; K. W. Kafitz; S. Stocker-Buschina

    \\u000a The song system is a model for studying the influence of steroids on the development of brain and behaviour [4, 14, 19]. It consists of anatomically discrete nuclei, that are sexually dimorphic and target regions for steroids [1, 7, chapter\\u000a by Lipp and Wolfer, present volume]. The main descending pathway for motor control of song production (Fig. 1) includes the

  19. Somatosensory Plasticity and Motor Learning

    PubMed Central

    Ostry, David J.; Darainy, Mohammad; Mattar, Andrew A.G.; Wong, Jeremy; Gribble, Paul L.

    2010-01-01

    Motor learning is dependent upon plasticity in motor areas of the brain, but does it occur in isolation or does it also result in changes to sensory systems? We examined changes to somatosensory function that occur in conjunction with motor learning. We found that even after periods of training as brief as 10 minutes, sensed limb position was altered and the perceptual change persisted for 24 hours. The perceptual change was reflected in subsequent movements; limb movements following learning deviated from the pre-learning trajectory by an amount that was not different in magnitude and in the same direction as the perceptual shift. Crucially, the perceptual change was dependent upon motor learning. When the limb was displaced passively such that subjects experienced similar kinematics but without learning, no sensory change was observed. The findings indicate that motor learning affects not only motor areas of the brain but changes sensory function as well. PMID:20392960

  20. Resting-state functional connectivity imaging of the mouse brain using photoacoustic tomography

    NASA Astrophysics Data System (ADS)

    Nasiriavanaki, Mohammadreza; Xia, Jun; Wan, Hanlin; Bauer, Adam Q.; Culver, Joseph P.; Wang, Lihong V.

    2014-03-01

    Resting-state functional connectivity (RSFC) imaging is an emerging neuroimaging approach that aims to identify spontaneous cerebral hemodynamic fluctuations and their associated functional connections. Clinical studies have demonstrated that RSFC is altered in brain disorders such as stroke, Alzheimer's, autism, and epilepsy. However, conventional neuroimaging modalities cannot easily be applied to mice, the most widely used model species for human brain disease studies. For instance, functional magnetic resonance imaging (fMRI) of mice requires a very high magnetic field to obtain a sufficient signal-to-noise ratio and spatial resolution. Functional connectivity mapping with optical intrinsic signal imaging (fcOIS) is an alternative method. Due to the diffusion of light in tissue, the spatial resolution of fcOIS is limited, and experiments have been performed using an exposed skull preparation. In this study, we show for the first time, the use of photoacoustic computed tomography (PACT) to noninvasively image resting-state functional connectivity in the mouse brain, with a large field of view and a high spatial resolution. Bilateral correlations were observed in eight regions, as well as several subregions. These findings agreed well with the Paxinos mouse brain atlas. This study showed that PACT is a promising, non-invasive modality for small-animal functional brain imaging.