These are representative sample records from Science.gov related to your search topic.
For comprehensive and current results, perform a real-time search at Science.gov.
1

Sources of abnormal EEG activity in brain infarctions.  

PubMed

EEGs from 16 patients with stroke in three different stages of evolution were recorded. EEG sources were calculated every 0.39 Hz by frequency domain VARETA. The main source was within the delta band in 2 out of 4 chronic patients, and in 67% of the patients in the acute or subacute stages when edema (cytotoxic or vasogenic) was present. Moreover, all patients showed abnormal activity in the theta band. Sources of abnormal activity in cortical or corticosubcortical infarcts were located in the cortex, surrounding the lesion. At the site of the infarct, a decrease of EEG power was observed. Sources of abnormal theta power coincided with edema and/or ischemic penumbra. PMID:11056837

Fernández-Bouzas, A; Harmony, T; Fernández, T; Silva-Pereyra, J; Valdés, P; Bosch, J; Aubert, E; Casián, G; Otero Ojeda, G; Ricardo, J; Hernández-Ballesteros, A; Santiago, E

2000-10-01

2

Maternal immune activation and abnormal brain development across CNS disorders.  

PubMed

Epidemiological studies have shown a clear association between maternal infection and schizophrenia or autism in the progeny. Animal models have revealed maternal immune activation (mIA) to be a profound risk factor for neurochemical and behavioural abnormalities in the offspring. Microglial priming has been proposed as a major consequence of mIA, and represents a critical link in a causal chain that leads to the wide spectrum of neuronal dysfunctions and behavioural phenotypes observed in the juvenile, adult or aged offspring. Such diversity of phenotypic outcomes in the mIA model are mirrored by recent clinical evidence suggesting that infectious exposure during pregnancy is also associated with epilepsy and, to a lesser extent, cerebral palsy in children. Preclinical research also suggests that mIA might precipitate the development of Alzheimer and Parkinson diseases. Here, we summarize and critically review the emerging evidence that mIA is a shared environmental risk factor across CNS disorders that varies as a function of interactions between genetic and additional environmental factors. We also review ongoing clinical trials targeting immune pathways affected by mIA that may play a part in disease manifestation. In addition, future directions and outstanding questions are discussed, including potential symptomatic, disease-modifying and preventive treatment strategies. PMID:25311587

Knuesel, Irene; Chicha, Laurie; Britschgi, Markus; Schobel, Scott A; Bodmer, Michael; Hellings, Jessica A; Toovey, Stephen; Prinssen, Eric P

2014-11-01

3

Abnormal Activity-Dependent Brain Lactate and Glutamate+Glutamine Responses in Panic Disorder  

PubMed Central

Background Prior evidence suggests panic disorder (PD) is characterized by neurometabolic abnormalities, including increased brain lactate responses to neural activation. Increased lactate responses could reflect a general upregulation of metabolic responses to neural activation. However, prior studies in PD have not measured activity-dependent changes in brain metabolites other than lactate. Here we examine activity-dependent changes in both lactate and glutamate plus glutamine (glx) in PD. Methods Twenty-one PD patients (13 remitted, 8 symptomatic) and 12 healthy volunteers were studied. A single-voxel, J-difference, magnetic resonance spectroscopy editing sequence was used to measure lactate and glx changes in visual cortex induced by visual stimulation. Results PD patients had significantly greater activity-dependent increases in brain lactate than healthy volunteers. The differences were significant for both remitted and symptomatic PD patients, who did not differ from each other. Activity-dependent changes in glx were significantly smaller in PD patients than in healthy volunteers. The temporal correlation between lactate and glx changes was significantly stronger in control subjects than in PD patients. Conclusions The novel demonstration that glx responses are diminished and temporally decoupled from lactate responses in PD contradicts the model of a general upregulation of activity-dependent brain metabolic responses in PD. The increase in activity-dependent brain lactate accumulation appears to be a trait feature of PD. Given the close relationship between lactate and pH in the brain, the findings are consistent with a model of brain metabolic and pH dysregulation associated with altered function of acid-sensitive fear circuits contributing to trait vulnerability in PD. PMID:23332354

Maddock, Richard J.; Buonocore, Michael H.; Miller, Amber R.; Yoon, Jong H.; Soosman, Steffan K.; Unruh, April M.

2013-01-01

4

Abnormal autonomic and associated brain activities during rest in autism spectrum disorder  

PubMed Central

Autism spectrum disorders are associated with social and emotional deficits, the aetiology of which are not well understood. A growing consensus is that the autonomic nervous system serves a key role in emotional processes, by providing physiological signals essential to subjective states. We hypothesized that altered autonomic processing is related to the socio-emotional deficits in autism spectrum disorders. Here, we investigated the relationship between non-specific skin conductance response, an objective index of sympathetic neural activity, and brain fluctuations during rest in high-functioning adults with autism spectrum disorder relative to neurotypical controls. Compared with control participants, individuals with autism spectrum disorder showed less skin conductance responses overall. They also showed weaker correlations between skin conductance responses and frontal brain regions, including the anterior cingulate and anterior insular cortices. Additionally, skin conductance responses were found to have less contribution to default mode network connectivity in individuals with autism spectrum disorders relative to controls. These results suggest that autonomic processing is altered in autism spectrum disorders, which may be related to the abnormal socio-emotional behaviours that characterize this condition. PMID:24424916

Eilam-Stock, Tehila; Xu, Pengfei; Cao, Miao; Gu, Xiaosi; Van Dam, Nicholas T.; Anagnostou, Evdokia; Kolevzon, Alexander; Soorya, Latha; Park, Yunsoo; Siller, Michael; He, Yong; Hof, Patrick R.

2014-01-01

5

Sources of abnormal EEG activity in the presence of brain lesions.  

PubMed

In routine clinical EEG, a common origin is assumed for delta and theta rhythms produced by brain lesions. In previous papers, we have provided some experimental support, based on High Resolution qEEG and dipole fitting in the frequency domain, for the hypothesis that delta and theta spectral power have independent origins related to lesion and edema respectively. This paper describes the results obtained with Frequency Domain VARETA (FD-VARETA) in a group of 13 patients with cortical space-occupying lesions, in order to: 1) Test the accuracy of FD-VARETA for the localization of brain lesions, and 2) To provide further support for the independent origin of delta and theta components. FD VARETA is a distributed inverse solution, constrained by the Montreal Neurological Institute probabilistic atlas that estimates the spectra of EEG sources. In all patients, logarithmic transformed source spectra were compared with age-matched normative values, defining the Z source spectrum. Maximum Z values were found in 10 patients within the delta band (1.56 to 3.12 Hz); the spatial extent of these sources in the atlas corresponded with the location of the tumors in the CT. In 2 patients with small metastases and large volumes of edema and in a patient showing only edema, maximum Z values were found between 4.29 and 5.12 Hz. The spatial extent of the sources at these frequencies was within the volume of the edema in the CT. These results provided strong support to the hypothesis that both delta and theta abnormal EEG activities are the counterparts of two different pathophysiological processes. PMID:10358783

Fernández-Bouzas, A; Harmony, T; Bosch, J; Aubert, E; Fernández, T; Valdés, P; Silva, J; Marosi, E; Martínez-López, M; Casián, G

1999-04-01

6

Abnormal Baseline Brain Activity in Patients with Pulsatile Tinnitus: A Resting-State fMRI Study  

PubMed Central

Numerous investigations studying the brain functional activity of the tinnitus patients have indicated that neurological changes are important findings of this kind of disease. However, the pulsatile tinnitus (PT) patients were excluded in previous studies because of the totally different mechanisms of the two subtype tinnitus. The aim of this study is to investigate whether altered baseline brain activity presents in patients with PT using resting-state functional magnetic resonance imaging (rs-fMRI) technique. The present study used unilateral PT patients (n = 42) and age-, sex-, and education-matched normal control subjects (n = 42) to investigate the changes in structural and amplitude of low-frequency (ALFF) of the brain. Also, we analyzed the relationships between these changes with clinical data of the PT patients. Compared with normal controls, PT patients did not show any structural changes. PT patients showed significant increased ALFF in the bilateral precuneus, and bilateral inferior frontal gyrus (IFG) and decreased ALFF in multiple occipital areas. Moreover, the increased THI score and PT duration was correlated with increased ALFF in precuneus and bilateral IFG. The abnormalities of spontaneous brain activity reflected by ALFF measurements in the absence of structural changes may provide insights into the neural reorganization in PT patients. PMID:24872895

Han, Lv; Zhaohui, Liu; Fei, Yan; Ting, Li; Pengfei, Zhao; Wang, Du; Cheng, Dong; Pengde, Guo; Xiaoyi, Han; Xiao, Wang; Rui, Li; Zhenchang, Wang

2014-01-01

7

Abnormal Activation of the Social Brain Network in Children with Autism Spectrum Disorder: An fMRI Study  

PubMed Central

Objective The aim of this study is to investigate abnormal findings of social brain network in Korean children with autism spectrum disorder (ASD) compared with typically developing children (TDC). Methods Functional magnetic resonance imaging (fMRI) was performed to examine brain activations during the processing of emotional faces (happy, fearful, and neutral) in 17 children with ASD, 24 TDC. Results When emotional face stimuli were given to children with ASD, various areas of the social brain relevant to social cognition showed reduced activation. Specifically, ASD children exhibited less activation in the right amygdala (AMY), right superior temporal sulcus (STS) and right inferior frontal gyrus (IFG) than TDC group when fearful faces were shown. Activation of left insular cortex and right IFG in response to happy faces was less in the ASD group. Similar findings were also found in left superior insular gyrus and right insula in case of neutral stimulation. Conclusion These findings suggest that children with ASD have different processing of social and emotional experience at the neural level. In other words, the deficit of social cognition in ASD could be explained by the deterioration of the capacity for visual analysis of emotional faces, the subsequent inner imitation through mirror neuron system (MNS), and the ability to transmit it to the limbic system and to process the transmitted emotion.

Kim, Sun-Young; Choi, Uk-Su; Park, Sung-Yeon; Oh, Se-Hong; Yoon, Hyo-Woon; Koh, Yun-Joo; Im, Woo-Young; Park, Jee-In; Song, Dong-Ho

2015-01-01

8

Abnormal brain activity during a reward and loss task in opiate-dependent patients receiving methadone maintenance therapy.  

PubMed

A core feature of human drug dependency is persistence in seeking and using drugs at the expense of other life goals. It has been hypothesized that addiction is associated with overvaluation of drug-related rewards and undervaluation of natural, nondrug-related rewards. Humans additionally tend to persist in using drugs despite adverse consequences. This suggests that the processing of both rewarding and aversive information may be abnormal in addictions. We used fMRI to examine neural responses to reward and loss events in opiate-dependent patients receiving methadone maintenance treatment (MMT, n=30) and healthy controls (n=23) using nondrug-related stimuli. Half of the patients were scanned after/before daily methadone intake (ADM/BDM patient groups). During reward trials, patients as a whole exhibited decreased neural discrimination between rewarding and nonrewarding outcomes in the dorsal caudate. Patients also showed reduced neural discrimination in the ventral striatum with regard to aversive and nonaversive outcomes and failed to encode successful loss avoidance as a reward signal in the ventral striatum. Patients also showed decreased insula activation during the anticipation/decision phase of loss events. ADM patients exhibited increased loss signals in the midbrain/parahippocampal gyrus, possibly related to a disinhibition of dopamine neurons. This study suggests that patients with opiate dependency on MMT exhibit abnormal brain activations to nondrug-related rewarding and loss events. Our findings add support to proposals that treatments for opiate addiction should aim to increase the reward value of nondrug-related rewarding events and highlight the importance of potential abnormalities in aversive information processing. PMID:24132052

Gradin, Victoria B; Baldacchino, Alex; Balfour, David; Matthews, Keith; Steele, J Douglas

2014-03-01

9

Abnormal baseline brain activity in drug-naïve patients with Tourette syndrome: a resting-state fMRI study  

PubMed Central

Tourette syndrome (TS) is a childhood-onset chronic disorder characterized by the presence of multiple motor and vocal tics. This study investigated spontaneous low-frequency fluctuations in TS patients during resting-state functional magnetic resonance imaging (rs-fMRI) scans. We obtained rs-fMRI scans from 17 drug-naïve TS children and 15 demographically matched healthy children. We computed the amplitude of low-frequency fluctuation (ALFF) and fractional ALFF (fALFF) of rs-fMRI data to measure spontaneous brain activity, and assessed the between-group differences in ALFF/fALFF and the relationship between ALFF/fALFF and tic severity scores. Our results showed that the children with TS exhibited significantly decreased ALFF in the posterior cingulate gyrus/precuneus and bilateral parietal gyrus. fALFF was decreased in TS children in the anterior cingulated cortex, bilateral middle and superior frontal cortices and superior parietal lobule, and increased in the left putamen and bilateral thalamus. Moreover, we found significantly positive correlations between fALFF and tic severity scores in the right thalamus. Our study provides empirical evidence for abnormal spontaneous neuronal activity in TS patients, which may implicate the underlying neurophysiological mechanism in TS and demonstrate the possibility of applying ALFF/fALFF for clinical TS studies. PMID:24427134

Cui, Yonghua; Jin, Zhen; Chen, Xu; He, Yong; Liang, Xia; Zheng, Yi

2014-01-01

10

Brain Abnormalities in Neuromyelitis Optica Spectrum Disorder  

PubMed Central

Neuromyelitis optica (NMO) is an idiopathic inflammatory syndrome of the central nervous system that is characterized by severe attacks of optic neuritis (ON) and myelitis. Until recently, NMO was considered a disease without brain involvement. However, since the discovery of NMO-IgG/antiaqaporin-4 antibody, the concept of NMO was broadened to NMO spectrum disorder (NMOSD), and brain lesions are commonly recognized. Furthermore, some patients present with brain symptoms as their first manifestation and develop recurrent brain symptoms without ON or myelitis. Brain lesions with characteristic locations and configurations can be helpful in the diagnosis of NMOSD. Due to the growing recognition of brain abnormalities in NMOSD, these have been included in the NMO and NMOSD diagnostic criteria or guidelines. Recent technical developments such as diffusion tensor imaging, MR spectroscopy, and voxel-based morphometry reveal new findings related to brain abnormalities in NMOSD that were not identified using conventional MRI. This paper focuses on the incidence and characteristics of the brain lesions found in NMOSD and the symptoms that they cause. Recent studies using advanced imaging techniques are also introduced. PMID:23259063

Kim, Woojun; Kim, Su-Hyun; Huh, So-Young; Kim, Ho Jin

2012-01-01

11

Abnormal brain connectivity in schizophrenia : investigations into episodic memory networks.  

E-print Network

??Abnormal connectivity between the prefrontal cortex (PFC) and other brain regions has been demonstrated in subjects with schizophrenia. We tested if abnormal connectivity, particularly between… (more)

Pelletier, Marc, 1973-

2005-01-01

12

Abnormal electroretinogram associated with developmental brain anomalies.  

PubMed Central

PURPOSE: We have encountered abnormal ERGs associated with optic nerve hypoplasia, macular, optic nerve and chorioretinal colobomata and developmental brain anomalies. Brain anomalies include cortical dysgenesis, lissencephaly, porencephaly, cerebellar and corpus callosum hypoplasia. We describe six exemplar cases. METHODS: Scotopic and photopic ERGs adherent to international standards were performed as well as photopic ERGs to long-duration stimuli. CT or MRI studies were also done. The ERGs were compared to age-matched normal control subjects. RESULTS: ERG changes include reduced amplitude b-waves to blue and red stimuli under scotopic testing conditions. Implicit times were often delayed. The photopic responses also showed reduced amplitude a- and b-waves with implicit time delays. The long-duration photopic ERG done in one case shows attenuation of both ON- and OFF-responses. CONCLUSIONS: Common underlying developmental genetic or environmental unifying casualties are speculated to be at fault in causing these cases of associated retinal and brain abnormalities. No single etiology is expected. Multiple potential causes acting early in embryogenesis effecting neuronal induction, migration and differentiation are theorized. These occur at a time when brain and retinal cells are sufficiently undifferentiated to be similarly effected. We call these cases examples of Brain Retina Neuroembryodysgenesis (BRNED). Homeobox and PAX genes with global neuronal developmental influences are gene candidates to unify the observed disruption of brain and retinal cell development. The ERG can provide a valuable clinical addition in understanding and ultimately classifying these disorders. Images FIGURE 1 FIGURE 4 FIGURE 5 FIGURE 6 FIGURE 7 FIGURE 8 PMID:8719676

Cibis, G W; Fitzgerald, K M

1995-01-01

13

Abnormal Asymmetry of Brain Connectivity in Schizophrenia  

PubMed Central

Recently, a growing body of data has revealed that beyond a dysfunction of connectivity among different brain areas in schizophrenia patients (SCZ), there is also an abnormal asymmetry of functional connectivity compared with healthy subjects. The loss of the cerebral torque and the abnormalities of gyrification, with an increased or more complex cortical folding in the right hemisphere may provide an anatomical basis for such aberrant connectivity in SCZ. Furthermore, diffusion tensor imaging studies have shown a significant reduction of leftward asymmetry in some key white-matter tracts in SCZ. In this paper, we review the studies that investigated both structural brain asymmetry and asymmetry of functional connectivity in healthy subjects and SCZ. From an analysis of the existing literature on this topic, we can hypothesize an overall generally attenuated asymmetry of functional connectivity in SCZ compared to healthy controls. Such attenuated asymmetry increases with the duration of the disease and correlates with psychotic symptoms. Finally, we hypothesize that structural deficits across the corpus callosum may contribute to the abnormal asymmetry of intra-hemispheric connectivity in schizophrenia. PMID:25566030

Ribolsi, Michele; Daskalakis, Zafiris J.; Siracusano, Alberto; Koch, Giacomo

2014-01-01

14

HMG-CoA reductase inhibitor rosuvastatin improves abnormal brain electrical activity via mechanisms involving eNOS.  

PubMed

Apart from its repressing effect on plasma lipid levels, 3-hydroxy-3-methyl glutaryl coenzyme A (HMG-CoA) reductase inhibitors exert neuroprotective functions in animal models of neurodegenerative disorders. In view of these promising observations, we were interested in whether HMG-CoA reductase inhibition would affect epileptiform activity in the brain. To elucidate this issue, atorvastatin, simvastatin and rosuvastatin were administered orally at a dose of 20mg/kg each for 3days and their anti-epileptic activities were tested and compared in rats. Epileptiform activity in the brain was induced by an intracortical penicillin G injection. Among HMG-CoA reductase inhibitors, simvastatin-treatment was less effective in terms of spike frequency as compared with atorvastatin- and rosuvastatin-treated animals. Atorvastatin treatment reduced spike frequencies and amplitudes significantly throughout the experiment. However, the most pronounced anti-epileptic effect was observed in rosuvastatin-treated animals, which was associated with improved blood-brain barrier (BBB) integrity, increased expression of endothelial nitric oxide synthase (eNOS) mRNA and decreased expressions of pro-apoptotic p53, Bax and caspase-3 mRNAs. Inhibition of eNOS activity with l-NG-Nitroarginine Methyl Ester (l-NAME) reversed the anti-epileptic effect of rosuvastatin significantly. However, l-NAME did not alter the effect of rosuvastatin on the levels of p53, Bax and caspase-3 mRNA expression. Here, we provide evidence that among HMG-CoA reductase inhibitors, rosuvastatin was the most effective statin on the reduction of epileptiform activity, which was associated with improved BBB permeability, increased expression of eNOS and decreased expressions of pro-apoptotic p53, Bax and caspase-3. Our observation also revealed that the anti-epileptic effect of rosuvastatin was dependent on the increased expression level of eNOS. The robust anti-epileptic effect encourages proof-of-concept studies with rosuvastatin in human epilepsy patients with hypercholesterolemia. PMID:25453767

Seker, F B; Kilic, U; Caglayan, B; Ethemoglu, M S; Caglayan, A B; Ekimci, N; Demirci, S; Dogan, A; Oztezcan, S; Sahin, F; Yilmaz, B; Kilic, E

2015-01-22

15

Impaired associative taste learning and abnormal brain activation in kinase-defective eEF2K mice.  

PubMed

Memory consolidation is defined temporally based on pharmacological interventions such as inhibitors of mRNA translation (molecular consolidation) or post-acquisition deactivation of specific brain regions (systems level consolidation). However, the relationship between molecular and systems consolidation are poorly understood. Molecular consolidation mechanisms involved in translation initiation and elongation have previously been studied in the cortex using taste-learning paradigms. For example, the levels of phosphorylation of eukaryotic elongation factor 2 (eEF2) were found to be correlated with taste learning in the gustatory cortex (GC), minutes following learning. In order to isolate the role of the eEF2 phosphorylation state at Thr-56 in both molecular and system consolidation, we analyzed cortical-dependent taste learning in eEF2K (the only known kinase for eEF2) ki mice, which exhibit reduced levels of eEF2 phosphorylation but normal levels of eEF2 and eEF2K. These mice exhibit clear attenuation of cortical-dependent associative, but not of incidental, taste learning. In order to gain a better understanding of the underlying mechanisms, we compared brain activity as measured by MEMRI (manganese-enhanced magnetic resonance imaging) between eEF2K ki mice and WT mice during conditioned taste aversion (CTA) learning and observed clear differences between the two but saw no differences under basal conditions. Our results demonstrate that adequate levels of phosphorylation of eEF2 are essential for cortical-dependent associative learning and suggest that malfunction of memory processing at the systems level underlies this associative memory impairment. PMID:22366775

Gildish, Iness; Manor, David; David, Orit; Sharma, Vijendra; Williams, David; Agarwala, Usha; Wang, Xuemin; Kenney, Justin W; Proud, Chris G; Rosenblum, Kobi

2012-03-01

16

DETECTION & MAPPING OF ABNORMAL BRAIN STRUCTURE IN METHAMPHETAMINE USERS  

E-print Network

help identify how drug abuse impacts the human brain, and provide therapeutic targets for drug-induced brain injury. Figure 1. Methamphetamine Effects on Brain Structure. ...... #12;DETECTION & MAPPING OF ABNORMAL BRAIN STRUCTURE IN METHAMPHETAMINE USERS 1 P.M. Thompson, 1 K

Thompson, Paul

17

Abnormal Brain Activation in Neurofibromatosis Type 1: A Link between Visual Processing and the Default Mode Network  

PubMed Central

Neurofibromatosis type 1 (NF1) is one of the most common single gene disorders affecting the human nervous system with a high incidence of cognitive deficits, particularly visuospatial. Nevertheless, neurophysiological alterations in low-level visual processing that could be relevant to explain the cognitive phenotype are poorly understood. Here we used functional magnetic resonance imaging (fMRI) to study early cortical visual pathways in children and adults with NF1. We employed two distinct stimulus types differing in contrast and spatial and temporal frequencies to evoke relatively different activation of the magnocellular (M) and parvocellular (P) pathways. Hemodynamic responses were investigated in retinotopically-defined regions V1, V2 and V3 and then over the acquired cortical volume. Relative to matched control subjects, patients with NF1 showed deficient activation of the low-level visual cortex to both stimulus types. Importantly, this finding was observed for children and adults with NF1, indicating that low-level visual processing deficits do not ameliorate with age. Moreover, only during M-biased stimulation patients with NF1 failed to deactivate or even activated anterior and posterior midline regions of the default mode network. The observation that the magnocellular visual pathway is impaired in NF1 in early visual processing and is specifically associated with a deficient deactivation of the default mode network may provide a neural explanation for high-order cognitive deficits present in NF1, particularly visuospatial and attentional. A link between magnocellular and default mode network processing may generalize to neuropsychiatric disorders where such deficits have been separately identified. PMID:22723888

Violante, Inês R.; Ribeiro, Maria J.; Cunha, Gil; Bernardino, Inês; Duarte, João V.; Ramos, Fabiana; Saraiva, Jorge; Silva, Eduardo; Castelo-Branco, Miguel

2012-01-01

18

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

ERIC Educational Resources Information Center

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

Minshew, Nancy J.

1996-01-01

19

Abnormal brain synchrony in Down Syndrome?  

PubMed Central

Down Syndrome is the most common genetic cause for intellectual disability, yet the pathophysiology of cognitive impairment in Down Syndrome is unknown. We compared fMRI scans of 15 individuals with Down Syndrome to 14 typically developing control subjects while they viewed 50 min of cartoon video clips. There was widespread increased synchrony between brain regions, with only a small subset of strong, distant connections showing underconnectivity in Down Syndrome. Brain regions showing negative correlations were less anticorrelated and were among the most strongly affected connections in the brain. Increased correlation was observed between all of the distributed brain networks studied, with the strongest internetwork correlation in subjects with the lowest performance IQ. A functional parcellation of the brain showed simplified network structure in Down Syndrome organized by local connectivity. Despite increased interregional synchrony, intersubject correlation to the cartoon stimuli was lower in Down Syndrome, indicating that increased synchrony had a temporal pattern that was not in response to environmental stimuli, but idiosyncratic to each Down Syndrome subject. Short-range, increased synchrony was not observed in a comparison sample of 447 autism vs. 517 control subjects from the Autism Brain Imaging Exchange (ABIDE) collection of resting state fMRI data, and increased internetwork synchrony was only observed between the default mode and attentional networks in autism. These findings suggest immature development of connectivity in Down Syndrome with impaired ability to integrate information from distant brain regions into coherent distributed networks. PMID:24179822

Anderson, Jeffrey S.; Nielsen, Jared A.; Ferguson, Michael A.; Burback, Melissa C.; Cox, Elizabeth T.; Dai, Li; Gerig, Guido; Edgin, Jamie O.; Korenberg, Julie R.

2013-01-01

20

Brain perfusion abnormalities in patients with euthyroid autoimmune thyroiditis  

Microsoft Academic Search

PurposeBrain perfusion abnormalities have recently been demonstrated by single-photon emission computed tomography (SPECT) in rare cases of severe Hashimoto’s thyroiditis (HT) encephalopathy; moreover, some degree of subtle central nervous system (CNS) involvement has been hypothesised in HT, but no direct evidence has been provided so far. The aim of this study was to assess cortical brain perfusion in patients with

M. Piga; A. Serra; L. Deiana; G. L. Loi; L. Satta; M. Di Liberto; S. Mariotti

2004-01-01

21

Brain Magnetic Resonance Imaging of Structural Abnormalities in Bipolar Disorder  

Microsoft Academic Search

Background: The neuropathogenesis of bipolar disor- der remains poorly described. Previous work suggests that patients with bipolar disorder may have abnormalities in neural pathways that are hypothesized to modulate hu- man mood states. We examined differences in brain struc- tural volumes associated with these pathways between patients with bipolar disorder hospitalized with mania and healthy community volunteers. Methods: Twenty-four patients

Stephen M. Strakowski; Melissa P. DelBello; Kenji W. Sax; Molly E. Zimmerman; Paula K. Shear; John M. Hawkins; Eric R. Larson

1999-01-01

22

Morphometric Brain Abnormalities in Boys with Conduct Disorder  

ERIC Educational Resources Information Center

Conduct disorder (CD) is associated with antisocial personality behavior that violates the basic rights of others. Results, on examining the structural brain aberrations in boys' CD, show that boys with CD and cormobid attention-deficit/hyperactivity disorder showed abnormalities in frontolimbic areas that could contribute to antisocial…

Huebner, Thomas; Vloet, Timo D.; Marx, Ivo; Konrad, Kerstin; Fink, Gereon R.; Herpertz, Sabine C.; Herpertz-Dahlmann, Beate

2008-01-01

23

Structural brain abnormalities in cervical dystonia  

PubMed Central

Background Idiopathic cervical dystonia is characterized by involuntary spasms, tremors or jerks. It is not restricted to a disturbance in the basal ganglia system because non-conventional voxel-based MRI morphometry (VBM) and diffusion tensor imaging (DTI) have detected numerous regional changes in the brains of patients. In this study scans of 24 patients with cervical dystonia and 24 age-and sex-matched controls were analysed using VBM, DTI and magnetization transfer imaging (MTI) using a voxel-based approach and a region-of-interest analysis. Results were correlated with UDRS, TWSTRS and disease duration. Results We found structural alterations in the basal ganglia; thalamus; motor cortex; premotor cortex; frontal, temporal and parietal cortices; visual system; cerebellum and brainstem of the patients with dystonia. Conclusions Cervical dystonia is a multisystem disease involving several networks such as the motor, sensory and visual systems. PMID:24131497

2013-01-01

24

Imaging of activated complement using ultrasmall superparamagnetic iron oxide particles (USPIO) - conjugated vectors: an in vivo in utero non-invasive method to predict placental insufficiency and abnormal fetal brain development.  

PubMed

In the current study, we have developed a magnetic resonance imaging-based method for non-invasive detection of complement activation in placenta and foetal brain in vivo in utero. Using this method, we found that anti-complement C3-targeted ultrasmall superparamagnetic iron oxide (USPIO) nanoparticles bind within the inflamed placenta and foetal brain cortical tissue, causing a shortening of the T2* relaxation time. We used two mouse models of pregnancy complications: a mouse model of obstetrics antiphospholipid syndrome (APS) and a mouse model of preterm birth (PTB). We found that detection of C3 deposition in the placenta in the APS model was associated with placental insufficiency characterised by increased oxidative stress, decreased vascular endothelial growth factor and placental growth factor levels and intrauterine growth restriction. We also found that foetal brain C3 deposition was associated with cortical axonal cytoarchitecture disruption and increased neurodegeneration in the mouse model of APS and in the PTB model. In the APS model, foetuses that showed increased C3 in their brains additionally expressed anxiety-related behaviour after birth. Importantly, USPIO did not affect pregnancy outcomes and liver function in the mother and the offspring, suggesting that this method may be useful for detecting complement activation in vivo in utero and predicting placental insufficiency and abnormal foetal neurodevelopment that leads to neuropsychiatric disorders.Molecular Psychiatry advance online publication, 23 September 2014; doi:10.1038/mp.2014.110. PMID:25245499

Girardi, G; Fraser, J; Lennen, R; Vontell, R; Jansen, M; Hutchison, G

2014-09-23

25

Brain abnormality segmentation based on l1-norm minimization  

NASA Astrophysics Data System (ADS)

We present a method that uses sparse representations to model the inter-individual variability of healthy anatomy from a limited number of normal medical images. Abnormalities in MR images are then defined as deviations from the normal variation. More precisely, we model an abnormal (pathological) signal y as the superposition of a normal part ~y that can be sparsely represented under an example-based dictionary, and an abnormal part r. Motivated by a dense error correction scheme recently proposed for sparse signal recovery, we use l1- norm minimization to separate ~y and r. We extend the existing framework, which was mainly used on robust face recognition in a discriminative setting, to address challenges of brain image analysis, particularly the high dimensionality and low sample size problem. The dictionary is constructed from local image patches extracted from training images aligned using smooth transformations, together with minor perturbations of those patches. A multi-scale sliding-window scheme is applied to capture anatomical variations ranging from fine and localized to coarser and more global. The statistical significance of the abnormality term r is obtained by comparison to its empirical distribution through cross-validation, and is used to assign an abnormality score to each voxel. In our validation experiments the method is applied for segmenting abnormalities on 2-D slices of FLAIR images, and we obtain segmentation results consistent with the expert-defined masks.

Zeng, Ke; Erus, Guray; Tanwar, Manoj; Davatzikos, Christos

2014-03-01

26

Seizure-induced brain lesions: a wide spectrum of variably reversible MRI abnormalities.  

PubMed

Introduction MRI abnormalities in the postictal period might represent the effect of the seizure activity, rather than its structural cause. Material and Methods Retrospective review of clinical and neuroimaging charts of 26 patients diagnosed with seizure-related MR-signal changes. All patients underwent brain-MRI (1.5-Tesla, standard pre- and post-contrast brain imaging, including DWI-ADC in 19/26) within 7 days from a seizure and at least one follow-up MRI, showing partial or complete reversibility of the MR-signal changes. Extensive clinical work-up and follow-up, ranging from 3 months to 5 years, ruled out infection or other possible causes of brain damage. Seizure-induced brain-MRI abnormalities remained a diagnosis of exclusion. Site, characteristics and reversibility of MRI changes, and association with characteristics of seizures were determined. Results MRI showed unilateral (13/26) and bilateral abnormalities, with high (24/26) and low (2/26) T2-signal, leptomeningeal contrast-enhancement (2/26), restricted diffusion (9/19). Location of abnormality was cortical/subcortical, basal ganglia, white matter, corpus callosum, cerebellum. Hippocampus was involved in 10/26 patients. Reversibility of MRI changes was complete in 15, and with residual gliosis or focal atrophy in 11 patients. Reversibility was noted between 15 and 150 days (average, 62 days). Partial simple and complex seizures were associated with hippocampal involvement (p=0.015), status epilepticus with incomplete reversibility of MRI abnormalities (p=0.041). Conclusions Seizure or epileptic status can induce transient, variably reversible MRI brain abnormalities. Partial seizures are frequently associated with hippocampal involvement and status epilepticus with incompletely reversible lesions. These seizure-induced MRI abnormalities pose a broad differential diagnosis; increased awareness may reduce the risk of misdiagnosis and unnecessary intervention. PMID:23787273

Cianfoni, A; Caulo, M; Cerase, A; Della Marca, G; Falcone, C; Di Lella, G M; Gaudino, S; Edwards, J; Colosimo, C

2013-11-01

27

Early Blood Gas Abnormalities and the Preterm Brain  

PubMed Central

The authors explored associations between blood gas abnormalities in more than 1,000 preterm infants during the first postnatal days and indicators of neonatal brain damage. During 2002–2004, women delivering infants before 28 weeks’ gestation at one of 14 participating institutions in 5 US states were asked to enroll in the study. The authors compared infants with blood gas values in the highest or lowest quintile for gestational age and postnatal day (extreme value) on at least 1 of the first 3 postnatal days with the remainder of the subjects, with separate analyses for blood gas abnormalities on multiple days and for partial pressure of oxygen in the alveolar gas of <35. Outcomes analyzed were ventriculomegaly and an echolucent lesion on an ultrasound scan in the neonatal intensive care unit, and cerebral palsy, microcephaly, and a low score on a Bayley Scale of Infant Development at 24 months. Every blood gas derangement (hypoxemia, hyperoxemia, hypocapnia, hypercapnia, and acidosis) was associated with multiple indicators of brain damage. However, for some, the associations were seen with only 1 day of exposure; others were evident with 2 or more days’ exposure. Findings suggest that individual blood gas derangements do not increase brain damage risk. Rather, the multiple derangements associated with indicators of brain damage might be indicators of immaturity/vulnerability and illness severity. PMID:20807736

Leviton, Alan; Allred, Elizabeth; Kuban, Karl C. K.; Dammann, Olaf; O'Shea, T. Michael; Hirtz, Deborah; Schreiber, Michael D.; Paneth, Nigel

2010-01-01

28

Abnormal MEG Oscillatory Activity during Visual Processing in the Prefrontal Cortices and Frontal Eye-Fields of the Aging HIV Brain  

PubMed Central

Objective Shortly after infection, HIV enters the brain and causes widespread inflammation and neuronal damage, which ultimately leads to neuropsychological impairments. Despite a large body of neuroscience and imaging studies, the pathophysiology of these HIV-associated neurocognitive disorders (HAND) remains unresolved. Previous neuroimaging studies have shown greater activation in HIV-infected patients during strenuous tasks in frontal and parietal cortices, and less activation in the primary sensory cortices during rest and sensory stimulation. Methods High-density magnetoencephalography (MEG) was utilized to evaluate the basic neurophysiology underlying attentive, visual processing in older HIV-infected adults and a matched non-infected control group. Unlike other neuroimaging methods, MEG is a direct measure of neural activity that is not tied to brain metabolism or hemodynamic responses. During MEG, participants fixated on a centrally-presented crosshair while intermittent visual stimulation appeared in their top-right visual-field quadrant. All MEG data was imaged in the time-frequency domain using beamforming. Results Uninfected controls had increased neuronal synchronization in the 6–12 Hz range within the right dorsolateral prefrontal cortex, right frontal eye-fields, and the posterior cingulate. Conversely, HIV-infected patients exhibited decreased synchrony in these same neural regions, and the magnitude of these decreases was correlated with neuropsychological performance in several cortical association regions. Conclusions MEG-based imaging holds potential as a noninvasive biomarker for HIV-related neuronal dysfunction, and may help identify patients who have or may develop HAND. Reduced synchronization of neural populations in the association cortices was strongly linked to cognitive dysfunction, and likely reflects the impact of HIV on neuronal and neuropsychological health. PMID:23840428

Wilson, Tony W.; Fox, Howard S.; Robertson, Kevin R.; Sandkovsky, Uriel; O’Neill, Jennifer; Heinrichs-Graham, Elizabeth; Knott, Nichole L.; Swindells, Susan

2013-01-01

29

Abuse of Amphetamines and Structural Abnormalities in Brain  

PubMed Central

We review evidence that structural brain abnormalities are associated with abuse of amphetamines. A brief history of amphetamine use/abuse, and evidence for toxicity is followed by a summary of findings from structural magnetic resonance imaging (MRI) studies of human subjects who had abused amphetamines and children who were exposed to amphetamines in utero. Evidence comes from studies that used a variety of techniques that include manual tracing, pattern matching, voxel-based, tensor-based, or cortical thickness mapping, quantification of white matter signal hyperintensities, and diffusion tensor imaging. Ten studies compared controls to individuals who were exposed to methamphetamine. Three studies assessed individuals exposed to 3-4-methylenedioxymethamphetamine (MDMA). Brain structural abnormalities were consistently reported in amphetamine abusers, as compared to control subjects. These included lower cortical gray matter volume and higher striatal volume than control subjects. These differences might reflect brain features that could predispose to substance dependence. High striatal volumes might also reflect compensation for toxicity in the dopamine-rich basal ganglia. Prenatal exposure was associated with striatal volume that was below control values, suggesting that such compensation might not occur in utero. Several forms of white matter abnormality are also common, and may involve gliosis. Many of the limitations and inconsistencies in the literature relate to techniques and cross-sectional designs, which cannot infer causality. Potential confounding influences include effects of pre-existing risk/protective factors, development, gender, severity of amphetamine abuse, abuse of other drugs, abstinence, and differences in lifestyle. Longitudinal designs in which multimodal datasets are acquired and are subjected to multivariate analyses would enhance our ability to provide general conclusions regarding the associations between amphetamine abuse and brain structure. PMID:18991959

Berman, Steven; O’Neill, Joseph; Fears, Scott; Bartzokis, George; London, Edythe D.

2009-01-01

30

Abnormal activity of default mode network in GERD patients  

PubMed Central

Background Abnormal processing of esophageal sensation at the level of the central nervous system has been proven to be involved in gastroesophageal reflux disease (GERD). However, most studies were focused on the possible functions of perceptual processing related network during task status, little attention has been paid to default mode network, which has been manifested to be important in the pathogenesis of many diseases. In our study, we compared the brain activity characteristic in GERD patients with the healthy subjects (HS) at baseline, looking for whether activities of default mode network were abnormal in GERD patients and attempting to identify their possible roles in GERD. In present study, fractional amplitude of low-frequency fluctuation was adopted to detect the brain activities at baseline. Group-level analyses were conducted by one-sample t test within groups (voxel thresholds were p?42, corrected P?90, corrected P?activity area in both groups mainly located in default mode network such as medial superior frontal gyrus, precuneus, posterior cingulate gyrus, etc. However, the activities of precuneus and posterior cingulate gyrus were significantly lower in GERD patients than those in the HS. Conclusions The activities of precuneus and posterior cingulate gyrus of default mode network in GERD patients were significantly lower compared to the HS, suggesting abnormal activities of brain regions in default mode network may be involved in pathophysiology of GERD symptom generation. PMID:23844702

2013-01-01

31

Monoamine abnormalities in the brain of scrapie-infected rats.  

PubMed

The effects of the scrapie agent on the levels of monoamines and their metabolites, and on choline acetyltransferase (CAT) activity have been investigated in discrete brain areas in the rat. Two strains of scrapie (8745 from sheep brain and C506 M3 from mice brain) were inoculated. Scrapie-infected rats showed a reduction in the levels of serotonin (prefrontal cortex, hippocampus, striatum) and dopamine (striatum) and an elevation of 5-HIAA levels (cerebral cortex, striatum, thalamus). Noradrenaline levels were decreased only in the cerebral cortex and cerebellum of rats infected with the scrapie strain C506 M3. CAT activity remained unchanged. These data suggest that the scrapie agent causes a derangement of noradrenergic, serotonergic and dopaminergic systems in the rat brain. PMID:6206919

Bassant, M H; Fage, D; Dedek, J; Cathala, F; Court, L; Scatton, B

1984-08-01

32

Blood-Brain Barrier Abnormalities Caused by HIV-1 gp120: Mechanistic and Therapeutic Implications  

PubMed Central

The blood-brain barrier (BBB) is compromised in many systemic and CNS diseases, including HIV-1 infection of the brain. We studied BBB disruption caused by HIV-1 envelope glycoprotein 120 (gp120) as a model. Exposure to gp120, whether acute [by direct intra-caudate-putamen (CP) injection] or chronic [using SV(gp120), an experimental model of ongoing production of gp120] disrupted the BBB, and led to leakage of vascular contents. Gp120 was directly toxic to brain endothelial cells. Abnormalities of the BBB reflect the activity of matrix metalloproteinases (MMPs). These target laminin and attack the tight junctions between endothelial cells and BBB basal laminae. MMP-2 and MMP-9 were upregulated following gp120-injection. Gp120 reduced laminin and tight junction proteins. Reactive oxygen species (ROS) activate MMPs. Injecting gp120 induced lipid peroxidation. Gene transfer of antioxidant enzymes protected against gp120-induced BBB abnormalities. NMDA upregulates the proform of MMP-9. Using the NMDA receptor (NMDAR-1) inhibitor, memantine, we observed partial protection from gp120-induced BBB injury. Thus, (1) HIV-envelope gp120 disrupts the BBB; (2) this occurs via lesions in brain microvessels, MMP activation and degradation of vascular basement membrane and vascular tight junctions; (3) NMDAR-1 activation plays a role in this BBB injury; and (4) antioxidant gene delivery as well as NMDAR-1 antagonists may protect the BBB. PMID:22448134

Louboutin, Jean-Pierre; Strayer, David S.

2012-01-01

33

Abnormal Brain Iron Homeostasis in Human and Animal Prion Disorders  

PubMed Central

Neurotoxicity in all prion disorders is believed to result from the accumulation of PrP-scrapie (PrPSc), a ?-sheet rich isoform of a normal cell-surface glycoprotein, the prion protein (PrPC). Limited reports suggest imbalance of brain iron homeostasis as a significant associated cause of neurotoxicity in prion-infected cell and mouse models. However, systematic studies on the generality of this phenomenon and the underlying mechanism(s) leading to iron dyshomeostasis in diseased brains are lacking. In this report, we demonstrate that prion disease–affected human, hamster, and mouse brains show increased total and redox-active Fe (II) iron, and a paradoxical increase in major iron uptake proteins transferrin (Tf) and transferrin receptor (TfR) at the end stage of disease. Furthermore, examination of scrapie-inoculated hamster brains at different timepoints following infection shows increased levels of Tf with time, suggesting increasing iron deficiency with disease progression. Sporadic Creutzfeldt-Jakob disease (sCJD)–affected human brains show a similar increase in total iron and a direct correlation between PrP and Tf levels, implicating PrPSc as the underlying cause of iron deficiency. Increased binding of Tf to the cerebellar Purkinje cell neurons of sCJD brains further indicates upregulation of TfR and a phenotype of neuronal iron deficiency in diseased brains despite increased iron levels. The likely cause of this phenotype is sequestration of iron in brain ferritin that becomes detergent-insoluble in PrPSc-infected cell lines and sCJD brain homogenates. These results suggest that sequestration of iron in PrPSc–ferritin complexes induces a state of iron bio-insufficiency in prion disease–affected brains, resulting in increased uptake and a state of iron dyshomeostasis. An additional unexpected observation is the resistance of Tf to digestion by proteinase-K, providing a reliable marker for iron levels in postmortem human brains. These data implicate redox-iron in prion disease–associated neurotoxicity, a novel observation with significant implications for prion disease pathogenesis. PMID:19283067

Mohan, Maradumane L.; Cohen, Mark L.; Chen, Fusong; Kong, Qingzhong; Bartz, Jason; Singh, Neena

2009-01-01

34

Complement inhibition and statins prevent fetal brain cortical abnormalities in a mouse model of preterm birth.  

PubMed

Premature babies are particularly vulnerable to brain injury. In this study we focus on cortical brain damage associated with long-term cognitive, behavioral, attentional or socialization deficits in children born preterm. Using a mouse model of preterm birth (PTB), we demonstrated that complement component C5a contributes to fetal cortical brain injury. Disruption of cortical dendritic and axonal cytoarchitecture was observed in PTB-mice. Fetuses deficient in C5aR (-/-) did not show cortical brain damage. Treatment with antibody anti-C5, that prevents generation of C5a, also prevented cortical fetal brain injury in PTB-mice. C5a also showed a detrimental effect on fetal cortical neuron development and survival in vitro. Increased glutamate release was observed in cortical neurons in culture exposed to C5a. Blockade of C5aR prevented glutamate increase and restored neurons dendritic and axonal growth and survival. Similarly, increased glutamate levels - measured by (1)HMRS - were observed in vivo in PTB-fetuses compared to age-matched controls. The blockade of glutamate receptors prevented C5a-induced abnormal growth and increased cell death in isolated fetal cortical neurons. Simvastatin and pravastatin prevented cortical fetal brain developmental and metabolic abnormalities -in vivo and in vitro. Neuroprotective effects of statins were mediated by Akt/PKB signaling pathways. This study shows that complement activation plays a crucial role in cortical fetal brain injury in PTL and suggests that complement inhibitors and statins might be good therapeutic options to improve neonatal outcomes in preterm birth. PMID:24184716

Pedroni, Silvia M A; Gonzalez, Juan M; Wade, Jean; Jansen, Maurits A; Serio, Andrea; Marshall, Ian; Lennen, Ross J; Girardi, Guillermina

2014-01-01

35

Neuropsychological Near Normality and Brain Structure Abnormality in Schizophrenia  

PubMed Central

Objective Cognitive deficits are prominent in schizophrenia. Patients have an average score one standard deviation below normal on a broad spectrum of cognitive tests. It has been repeatedly noted, however, that 20%–25% of patients differ from this general pattern and score close to normal on neuropsychological testing. This study used brain morphometry to 1) identify brain abnormalities associated with more severe cognitive deficits and 2) help determine whether cognitively relatively intact patients perform better because they have less severe illness or because they have a different illness. Method Patients were assigned to a neuropsychologically near normal (N=21) subgroup if they scored within 0.5 standard deviation of healthy comparison subjects (N=30) on four tests of attention and verbal and nonverbal working memory, and to a neuropsychologically impaired (N= 54) group if they scored at least 1.0 standard deviation below that of comparison subjects. Subgroup assignments were confirmed with the California Verbal Learning Test and degraded-stimulus Continuous Performance Test. Volumes of ventricular compartments, hippocampus, amygdala, thalamus, cerebellum, and regional cortical gray and white matter were dependent variables. Differences among groups were evaluated by using linear mixed-model multivariate analyses with gender, age, and height as covariates. Results Both neuropsychologically near normal and neuropsychologically impaired patients had markedly smaller gray matter and larger third ventricle volumes than healthy comparison subjects. Only neuropsychologically impaired patients, however, had significantly smaller white matter and larger lateral ventricle volumes than healthy comparison subjects. Conclusions Although both neuropsychologically impaired and neuropsycho-logically near normal patients have marked neuropathology in their gray matter, the relative absence of white matter pathology in the neuropsychologically near normal group suggests the possibility of differences in the disease process. PMID:18765481

Wexler, Bruce E.; Zhu, Hongtu; Bell, Morris D.; Nicholls, Sarah S.; Fulbright, Robert K.; Gore, John C.; Colibazzi, Tiziano; Amat, Jose; Bansal, Ravi; Peterson, Bradley S.

2015-01-01

36

Detection of abnormal diffuse perfusion in SPECT using a normal brain atlas  

NASA Astrophysics Data System (ADS)

Despite the advent of sophisticated image analysis algorithms, most SPECT (Single Photon Emission Computerized Tomography)cerebral perfusion studies are assessed visually, leading to unavoidable and significant inter and intra-observer variability. Here, we present an automatic method for evaluating SPECT studies based on a computerized atlas of normal regional cerebral bloodflow(rCBF). To generate the atlas, normal(screened volunteers)brain SPECT studies are registered with an affine transformation to one of them arbitrarily selected as reference to remove any size and orientation variations that are assumed irrelevant for our analysis. Then a smooth non-linear registration is performed to reveal the local activity pattern displacement among the normal subjects. By computing and applying the mean displacement to the reference SPECT image, one obtain the atlas that is the normal mean distribution of the rCBF(up to an affine transformation difference). To complete the atlas we add the intensity variance with the displacement mean and variance of the activity pattern. To investigate a patient's condition, we proceed similarly to the atlas construction phase. We first register the patient's SPECT volume to the atlas with an affine transformation. Then the algorithm computes the non-linear 3D displacement of each voxel needed for an almost perfect shape (but not intensity)fit with the atlas. For each brain voxel, if the intensity difference between the atlas and the registered patient is higher than normal differences then this voxel is counted as "abnormal" and similarly if the 3D motion necessary to move the voxel to its registered position is not within the normal displacements. Our hypothesis is that this number of abnormal voxels discriminates between normal and abnormal studies. A Markovian segmentation algorithm that we have presented elsewhere is also used to identify the white and gray matters for regional analysis. We validated this approachusing 23 SPECT perfusion studies (99mTc ECD)selected visually for clear diffuse anomalies (a much more stringent test than "easy" focal lesions detection) and 21 normal studies. A leave-one-out strategy was used to test our approach to avoid any bias. Based on the number of "abnormal" voxels, two simple supervised classifiers were tested:(1)minimum distance-to-mean and (2)Bayesian. A voxel was considered "abnormal" if its P value with respect to the atlas was lower that 0.01(1%). The results show that for the whole brain, a combination of the number of intensity and displacement "abnormal" voxel is a powerful discriminant with a 91% classification rate. If we focus only on the voxels in the segmented gray matter the rates are slighty higher.

Laliberte, Jean-Francois; Meunier, Jean; Mignotte, Max; Soucy, Jean-Paul

2003-05-01

37

Brain death and bioelectrical brain activity  

Microsoft Academic Search

The effect of mechanical vibration and light stimulation on the ongoing and evoked bioelectrical activity was studied in two cases with clinically defined brain death and two other patients with severe head injury, one of them with an isoelectric EEG. The importance of such stimulation sequences for the definition of brain death is discussed, with particular emphasis on mechanical vibration.

G. Pfurtscheller; G. Schwarz; W. List

1985-01-01

38

mTOR signaling and its roles in normal and abnormal brain development  

PubMed Central

Target of rapamycin (TOR) was first identified in yeast as a target molecule of rapamycin, an anti-fugal and immunosuppressant macrolide compound. In mammals, its orthologue is called mammalian TOR (mTOR). mTOR is a serine/threonine kinase that converges different extracellular stimuli, such as nutrients and growth factors, and diverges into several biochemical reactions, including translation, autophagy, transcription, and lipid synthesis among others. These biochemical reactions govern cell growth and cause cells to attain an anabolic state. Thus, the disruption of mTOR signaling is implicated in a wide array of diseases such as cancer, diabetes, and obesity. In the central nervous system, the mTOR signaling cascade is activated by nutrients, neurotrophic factors, and neurotransmitters that enhances protein (and possibly lipid) synthesis and suppresses autophagy. These processes contribute to normal neuronal growth by promoting their differentiation, neurite elongation and branching, and synaptic formation during development. Therefore, disruption of mTOR signaling may cause neuronal degeneration and abnormal neural development. While reduced mTOR signaling is associated with neurodegeneration, excess activation of mTOR signaling causes abnormal development of neurons and glia, leading to brain malformation. In this review, we first introduce the current state of molecular knowledge of mTOR complexes and signaling in general. We then describe mTOR activation in neurons, which leads to translational enhancement, and finally discuss the link between mTOR and normal/abnormal neuronal growth during development. PMID:24795562

Takei, Nobuyuki; Nawa, Hiroyuki

2014-01-01

39

Spontaneous brain activity in combat related PTSD.  

PubMed

Posttraumatic stress disorder (PTSD) is a prevalent psychiatric disorder, especially in combat veterans. Existing functional neuroimaging studies have provided important insights into the neural mechanisms of PTSD using various experimental paradigms involving trauma recollection or other forms of emotion provocation. However it is not clear whether the abnormal brain activity is specific to the mental processes related to the experimental tasks or reflects general patterns across different brain states. Thus, studying intrinsic spontaneous brain activity without the influence of external tasks may provide valuable alternative perspectives to further understand the neural characteristics of PTSD. The present study evaluated the magnitudes of spontaneous brain activity of male US veterans with or without PTSD, with the two groups matched on age, gender, and ethnicity. Amplitudes of low frequency fluctuation (ALFF), a data driven analysis method, were calculated on each voxel of the resting state fMRI data to measure the magnitudes of spontaneous brain activity. Results revealed that PTSD subjects showed increased spontaneous activity in the amygdala, ventral anterior cingulate cortex, insula, and orbital frontal cortex, as well as decreased spontaneous activity in the precuneus, dorsal lateral prefrontal cortex and thalamus. Within the PTSD group, larger magnitudes of spontaneous activity in the thalamus, precuneus and dorsal lateral prefrontal cortex were associated with lower re-experiencing symptoms. Comparing our results with previous functional neuroimaging findings, increased activity of the amygdala and anterior insula and decreased activity of the thalamus are consistent patterns across emotion provocation states and the resting state. PMID:23643995

Yan, Xiaodan; Brown, Adam D; Lazar, Mariana; Cressman, Victoria L; Henn-Haase, Clare; Neylan, Thomas C; Shalev, Arieh; Wolkowitz, Owen M; Hamilton, Steven P; Yehuda, Rachel; Sodickson, Daniel K; Weiner, Michael W; Marmar, Charles R

2013-06-28

40

Anxiety and error-related brain activity  

Microsoft Academic Search

Error-related negativity (ERN\\/Ne) is a component of the event-related brain potential (ERP) associated with monitoring action and detecting errors. It is a sharp negative deflection that generally occurs from 50 to 150 ms following response execution and has been associated with anterior cingulate cortex (ACC) activity. An enhanced ERN has been observed in patients with obsessive-compulsive disorder (OCD)—reflecting abnormal ACC

Greg Hajcak; Nicole McDonald; Robert F. Simons

2003-01-01

41

ABNORMALITIES IN THE TRICARBOXYLIC ACID (TCA) CYCLE IN BRAIN OF SCHIZOPHRENIA PATIENTS  

PubMed Central

Images of brain metabolism and measurements of activities of components of the electron transport chain support earlier studies that suggest that brain glucose oxidation is inherently abnormal in a significant proportion of persons with schizophrenia. Therefore, we measured activities of enzymes of the tricarboxylic (TCA) cycle in dorsolateral-prefrontal-cortex from schizophrenia patients (N=13) and non-psychiatric disease controls (N=13): the pyruvate dehydrogenase complex (PDHC), citrate synthase (CS), aconitase, isocitrate dehydrogenase (ICDH), the alpha-ketoglutarate dehydrogenase complex (KGDHC), succinate thiokinase (STH), succinate dehydrogenase (SDH), fumarase and malate dehydrogenase (MDH). Activities of aconitase (18.4%, p<0.05), KGDHC (26%) and STH (28.2%, p<0.05), enzymes in the first half of the TCA cycle, were lower, but SDH (18.3%, p<0.05) and MDH (34%, p<0.005), enzymes in the second half, were higher than controls. PDHC, CS, ICDH and fumarase activities were unchanged. There were no significant correlations between enzymes of TCA cycle and cognitive function, age or choline acetyl transferase activity, except for aconitase activity which decreased slightly with age (r=0.55, p=003). The increased activities of dehydrogenases in the second half of the TCA cycle may reflect a compensatory response to reduced activities of enzymes in the first half. Such alterations in the components of TCA cycle are adequate to alter the rate of brain metabolism. These results are consistent with the imaging studies of hypometabolism in schizophrenia. They suggest that deficiencies in mitochondrial enzymes can be associated with mental disease that takes the form of schizophrenia. PMID:21123035

Bubber, P; Hartounian, V; Gibson, GE; Blass, JP

2010-01-01

42

Abnormal structural and functional brain connectivity in gray matter heterotopia  

E-print Network

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

Christodoulou, Joanna

43

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

ERIC Educational Resources Information Center

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

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

2010-01-01

44

Infantile Autism and Computerized Tomography Brain-Scan Findings: Specific versus Nonspecific Abnormalities.  

ERIC Educational Resources Information Center

The study of computerized tomography brain-scan findings with 45 autistic and 19 control subjects concluded that autism is nonspecifically associated with brain-scan abnormalities, and that other nonorganic, as well as organic, factors should be taken into account. (Author/DB)

Balottin, Umberto; And Others

1989-01-01

45

Brain Abnormality Found in Group of SIDS Cases  

MedlinePLUS

... of age. The deaths are associated with an infant’s sleep period. The study was published online in Acta ... Dr. Kinney said the findings suggest that in infants with the hippocampal abnormality, an unsafe sleep environment may trigger an underlying instability in heart ...

46

Abnormal brain development in newborns with congenital heart disease  

Microsoft Academic Search

BACKGROUND: Congenital heart disease in newborns is associated with global impairment in development. We characterized brain metabolism and microstructure, as measures of brain maturation, in newborns with congenital heart disease before they underwent heart surgery. METHODS: We studied 41 term newborns with congenital heart disease--29 who had transposition of the great arteries and 12 who had single-ventricle physiology--with the use

S Miller; P McQuillen; S Hamrick; D Xu; D Glidden; N Charlton; T Karl; A Azakie; D Ferriero; A Barkovich; D Vigneron

2007-01-01

47

Neuroanatomy of "hearing voices": a frontotemporal brain structural abnormality associated with auditory hallucinations in schizophrenia.  

PubMed

Auditory hallucinations are a frequent symptom in schizophrenia. While functional imaging studies have suggested the association of certain patterns of brain activity with sub-syndromes or single symptoms (e.g. positive symptoms such as hallucinations), there has been only limited evidence from structural imaging or post-mortem studies. In this study, we investigated the relation of local brain structural deficits to severity of auditory hallucinations, particularly in perisylvian areas previously reported to be involved in auditory hallucinations. In order to overcome certain limitations of conventional volumetric methods, we used deformation-based morphometry (DBM), a novel automated whole-brain morphometric technique, to assess local gray and white matter deficits in structural magnetic resonance images of 85 schizophrenia patients. We found severity of auditory hallucinations to be significantly correlated (P < 0.001) with volume loss in the left transverse temporal gyrus of Heschl (primary auditory cortex) and left (inferior) supramarginal gyrus, as well as middle/inferior right prefrontal gyri. This demonstrates a pattern of distributed structural abnormalities specific for auditory hallucinations and suggests hallucination-specific alterations in areas of a frontotemporal network for processing auditory information and language. PMID:14654460

Gaser, Christian; Nenadic, Igor; Volz, Hans-Peter; Büchel, Christian; Sauer, Heinrich

2004-01-01

48

Abnormal "Shape Activity" Detection and Tracking Namrata Vaswani  

E-print Network

of activity, e.g. person taller/shorter · Scaled orthographic camera motion ­ Small field of view PTZ camera in traffic ­ Abnormal Human Action detection, e.g. motion disorders · Sequence Id & Tracking ­ Sequence, view invariant approaches, multiple levels of zoom, DBN, co-occurrence statistics Abnormal "Shape

Vaswani, Namrata

49

Brain morphological abnormalities in 49,XXXXY syndrome: A pediatric magnetic resonance imaging study???  

PubMed Central

As a group, people with the sex chromosome aneuploidy 49,XXXXY have characteristic physical and cognitive/behavioral tendencies, although there is high individual variation. In this study we use magnetic resonance imaging (MRI) to examine brain morphometry in 14 youth with 49,XXXXY compared to 42 age-matched healthy controls. Total brain size was significantly smaller (t = 9.0, p < .001), and rates of brain abnormalities such as colpocephaly, plagiocephaly, periventricular cysts, and minor craniofacial abnormalities were significantly increased. White matter lesions were identified in 50% of subjects, supporting the inclusion of 49,XXXXY in the differential diagnosis of small multifocal white matter lesions. Further evidence of abnormal development of white matter was provided by the smaller cross sectional area of the corpus callosum. These results suggest that increased dosage of genes on the X chromosome has adverse effects on white matter development. PMID:23667827

Blumenthal, Jonathan D.; Baker, Eva H.; Lee, Nancy Raitano; Wade, Benjamin; Clasen, Liv S.; Lenroot, Rhoshel K.; Giedd, Jay N.

2013-01-01

50

Brain Structure Abnormalities in Adolescent Girls with Conduct Disorder  

ERIC Educational Resources Information Center

Background: Conduct disorder (CD) in female adolescents is associated with a range of negative outcomes, including teenage pregnancy and antisocial personality disorder. Although recent studies have documented changes in brain structure and function in male adolescents with CD, there have been no neuroimaging studies of female adolescents with CD.…

Fairchild, Graeme; Hagan, Cindy C.; Walsh, Nicholas D.; Passamonti, Luca; Calder, Andrew J.; Goodyer, Ian M.

2013-01-01

51

Childhood Onset Schizophrenia: Cortical Brain Abnormalities as Young Adults  

ERIC Educational Resources Information Center

Background: Childhood onset schizophrenia (COS) is a rare but severe form of the adult onset disorder. While structural brain imaging studies show robust, widespread, and progressive gray matter loss in COS during adolescence, there have been no longitudinal studies of sufficient duration to examine comparability with the more common adult onset…

Greenstein, Deanna; Lerch, Jason; Shaw, Philip; Clasen, Liv; Giedd, Jay; Gochman, Peter; Rapoport, Judith; Gogtay, Nitin

2006-01-01

52

Gyrification brain abnormalities associated with adolescence and early-adulthood cannabis use  

Microsoft Academic Search

Although cannabis is the most widely used illicit drug in the world, the long-term effect of its use in the brain remains controversial. In order to determine whether adolescence and early-adulthood cannabis use is associated with gross volumetric and gyrification abnormalities in the brain, we set up a cross-sectional study using structural magnetic resonance imaging in a sample of general

Ignacio Mata; Rocio Perez-Iglesias; Roberto Roiz-Santiañez; Diana Tordesillas-Gutierrez; Angel Pazos; Agustin Gutierrez; Jose Luis Vazquez-Barquero; Benedicto Crespo-Facorro

2010-01-01

53

Abnormal brain structure in youth who commit homicide  

PubMed Central

Background Violence that leads to homicide results in an extreme financial and emotional burden on society. Juveniles who commit homicide are often tried in adult court and typically spend the majority of their lives in prison. Despite the enormous costs associated with homicidal behavior, there have been no serious neuroscientific studies examining youth who commit homicide. Methods Here we use neuroimaging and voxel-based morphometry to examine brain gray matter in incarcerated male adolescents who committed homicide (n = 20) compared with incarcerated offenders who did not commit homicide (n = 135). Two additional control groups were used to understand further the nature of gray matter differences: incarcerated offenders who did not commit homicide matched on important demographic and psychometric variables (n = 20) and healthy participants from the community (n = 21). Results Compared with incarcerated adolescents who did not commit homicide (n = 135), incarcerated homicide offenders had reduced gray matter volumes in the medial and lateral temporal lobes, including the hippocampus and posterior insula. Feature selection and support vector machine learning classified offenders into the homicide and non-homicide groups with 81% overall accuracy. Conclusions Our results indicate that brain structural differences may help identify those at the highest risk for committing serious violent offenses. PMID:24936430

Cope, L.M.; Ermer, E.; Gaudet, L.M.; Steele, V.R.; Eckhardt, A.L.; Arbabshirani, M.R.; Caldwell, M.F.; Calhoun, V.D.; Kiehl, K.A.

2014-01-01

54

Statistical distribution of blood serotonin as a predictor of early autistic brain abnormalities  

PubMed Central

Background A wide range of abnormalities has been reported in autistic brains, but these abnormalities may be the result of an earlier underlying developmental alteration that may no longer be evident by the time autism is diagnosed. The most consistent biological finding in autistic individuals has been their statistically elevated levels of 5-hydroxytryptamine (5-HT, serotonin) in blood platelets (platelet hyperserotonemia). The early developmental alteration of the autistic brain and the autistic platelet hyperserotonemia may be caused by the same biological factor expressed in the brain and outside the brain, respectively. Unlike the brain, blood platelets are short-lived and continue to be produced throughout the life span, suggesting that this factor may continue to operate outside the brain years after the brain is formed. The statistical distributions of the platelet 5-HT levels in normal and autistic groups have characteristic features and may contain information about the nature of this yet unidentified factor. Results The identity of this factor was studied by using a novel, quantitative approach that was applied to published distributions of the platelet 5-HT levels in normal and autistic groups. It was shown that the published data are consistent with the hypothesis that a factor that interferes with brain development in autism may also regulate the release of 5-HT from gut enterochromaffin cells. Numerical analysis revealed that this factor may be non-functional in autistic individuals. Conclusion At least some biological factors, the abnormal function of which leads to the development of the autistic brain, may regulate the release of 5-HT from the gut years after birth. If the present model is correct, it will allow future efforts to be focused on a limited number of gene candidates, some of which have not been suspected to be involved in autism (such as the 5-HT4 receptor gene) based on currently available clinical and experimental studies. PMID:16029508

Janušonis, Skirmantas

2005-01-01

55

Abnormal T2Weighted MRI Signal Surrounding Leads in a Subset of Deep Brain Stimulation Patients  

Microsoft Academic Search

Background: Deep brain stimulation (DBS) surgery is a common treatment option for numerous neurological disorders. However, it is not without potential complications, such as hemorrhage and infection. Interestingly, we have observed several instances of abnormal T2-weighted signal hyperintensity surrounding DBS leads on postoperative MRI that are not associated with hemorrhage or infection. Methods: To better characterize the incidence and timing

Dario J. Englot; Christine M. Glastonbury; Paul S. Larson

2011-01-01

56

Research Papers Abnormal brain chemistry in chronic back pain: an in vivo proton  

E-print Network

Research Papers Abnormal brain chemistry in chronic back pain: an in vivo proton magnetic resonance April 2000; accepted 2 May 2000 Abstract The neurobiology of chronic pain, including chronic back pain, is unknown. Structural imaging studies of the spine cannot explain all cases of chronic back pain. Functional

Apkarian, A. Vania

57

Prolonged acute migraine with aura and reversible brain MRI abnormalities after liquid sclerotherapy  

PubMed Central

Transient visual disturbances constitute the most commonly reported neurological side effect during and immediately after sclerotherapy. A few studies, based on clinical and diffusion-weighted MRI assessments, have suggested that these transient neurological symptoms correspond to migraine with aura. Recently, it has been reported that brain magnetic resonance imaging can reveal transient T2*-weighted abnormalities during the acute phase of migraine with aura. We reported a 36-year-old man who presented with transient neurological symptoms and concomitant T2*-weighted abnormalities on brain magnetic resonance imaging immediately after liquid sclerotherapy. We hypothesize that the reversible nature of the patient’s T2*-weighted abnormalities may indicate a relationship with the post-sclerotherapy migraine with aura attack. PMID:24948446

2014-01-01

58

Neuromagnetic source imaging of abnormal spontaneous activity in tinnitus patient modulated by electrical cortical stimulation.  

PubMed

Electrical cortical stimulation (CS) of the auditory cortices has been shown to reduce the severity of debilitating tinnitus in some patients. In this study, we performed MEG source imaging of spontaneous brain activity during concurrent CS of the left secondary auditory cortex of a volunteer suffering from right unilateral tinnitus. CS produced MEG artifacts which were successfully sorted and removed using a combination of sensor and source level signal separation and classification techniques. This contribution provides the first proof of concept reporting on analysis of MEG data with concurrent CS. Effects of CS on ongoing brain activity were revealed at the MEG sensor and source levels and indicate CS significantly reduced ongoing brain activity in the lower frequency range (<40Hz), and emphasized its higher (>40Hz), gamma range components. Further, our results show that CS increased the spectral correlation across multiple frequency bands in the low and high gamma ranges, and between the alpha and beta bands of the MEG. Finally, MEG sources localized in the auditory cortices and nearby regions exhibited abnormal spectral activity that was suppressed by CS. These results provide promising evidence in favor of the Thalamocortical Dysrhytmia (TCD) hypothesis of tinnitus, and suggest that CS may prove to be an effective treatment of tinnitus when targeted to brain regions exhibiting abnormal spontaneous activity. PMID:19964017

Ramirez, Rey Rene; Kopell, Brian Harris; Butson, Christopher R; Gaggl, Wolfgang; Friedland, David R; Baillet, Sylvain

2009-01-01

59

Abnormal brain magnetic resonance imaging in two patients with Smith-Magenis syndrome.  

PubMed

Smith-Magenis syndrome (SMS) is a clinically recognizable contiguous gene syndrome ascribed to an interstitial deletion in chromosome 17p11.2. Seventy percent of SMS patients have a common deletion interval spanning 3.5 megabases (Mb). Clinical features of SMS include characteristic mild dysmorphic features, ocular anomalies, short stature, brachydactyly, and hypotonia. SMS patients have a unique neurobehavioral phenotype that includes intellectual disability, self-injurious behavior and severe sleep disturbance. Little has been reported in the medical literature about anatomical brain anomalies in patients with SMS. Here we describe two patients with SMS caused by the common deletion in 17p11.2 diagnosed using chromosomal microarray (CMA). Both patients had a typical clinical presentation and abnormal brain magnetic resonance imaging (MRI) findings. One patient had subependymal periventricular gray matter heterotopia, and the second had a thin corpus callosum, a thin brain stem and hypoplasia of the cerebellar vermis. This report discusses the possible abnormal MRI images in SMS and reviews the literature on brain malformations in SMS. Finally, although structural brain malformations in SMS patients are not a common feature, we suggest baseline routine brain imaging in patients with SMS in particular, and in patients with chromosomal microdeletion/microduplication syndromes in general. Structural brain malformations in these patients may affect the decision-making process regarding their management. PMID:24788350

Maya, Idit; Vinkler, Chana; Konen, Osnat; Kornreich, Liora; Steinberg, Tamar; Yeshaya, Josepha; Latarowski, Victoria; Shohat, Mordechai; Lev, Dorit; Baris, Hagit N

2014-08-01

60

Abnormal activation of the motor cortical network in idiopathic scoliosis demonstrated by functional MRI  

Microsoft Academic Search

The aetiology of idiopathic scoliosis (IS) remains unknown, but there is growing support for the possibility of an underlying\\u000a neurological disorder. Functional magnetic resonance imaging (fMRI) can characterize the abnormal activation of the sensorimotor\\u000a brain network in movement disorders and could provide further insights into the neuropathogenesis of IS. Twenty subjects were\\u000a included in the study; 10 adolescents with IS

Julio Domenech; G. García-Martí; L. Martí-Bonmatí; C. Barrios; J. M. Tormos; A. Pascual-Leone

61

Brain Gym. Simple Activities for Whole Brain Learning.  

ERIC Educational Resources Information Center

This booklet contains simple movements and activities that are used with students in Educational Kinesiology to enhance their experience of whole brain learning. Whole brain learning through movement repatterning and Brain Gym activities enable students to access those parts of the brain previously unavailable to them. These movements of body and…

Dennison, Paul E.; Dennison, Gail E.

62

Abnormal amygdala activation profile in pedophilia  

Microsoft Academic Search

Despite considerable public interest research in neurobiological correlates of pedophilia is scarce. Since amygdala activation\\u000a is central for emotional valuation, arousal, and salience, we investigated the activation profile of this structure in 10\\u000a male subjects with pedophilia (exclusively attracted to boys), all convicted sex-offenders and sentenced to forensic psychiatric\\u000a treatment along with ten male heterosexual matched controls. We used a

Alexander Sartorius; Matthias Ruf; Christine Kief; Traute Demirakca; Josef Bailer; Gabriele Ende; Fritz A. Henn; Andreas Meyer-Lindenberg; Harald Dressing

2008-01-01

63

Abnormal brain aging as a radical-related disease: A new target for nuclear medicine  

SciTech Connect

DNA damages caused by endogenously produced radicals are closely correlated with aging. Among them, mitochondrial DNA (mtDNA) deletions have been reported as a memory of DNA damage by oxygen radicals. In fact, clinical as well as experimental studies indicated the accumulation of deleted mtDNA in the brain, myocardium and son on, in aged subjects. In our previous work, radioiodinated radical trapping agent, p-iodophenyl-N-t-butylnitrone, and hypoxia imaging agent, Cu-62 diacetyl-bis-N-4-methyl-thiosemicarbazone have been developed for the diagnosis of radical-related diseases, such as ischemic, inflammation, cancer or aging. The aim of the present work was to evaluate these agents for brain aging studies. In our university, an unique animal model, a senescence accelerated model mouse (SAM), has been established. Among the various substrains, SAMP8 showing memory deterioration in its young age ({approximately}3 month) was basically evaluated as an abnormal brain aging model with mtDNA deletion. As controls, SAMR1 showing normal aging and ddY mice were used. MtDNA deletion n the brain was analyzed with polymerase-chain reaction (PCR) method, and relationship between mtDNA deletion and brain uptake of IPBN or Cu-62-ATSM was studied. In 1-3 month old SAMP8 brain, multiple mtDNa deletions were already found and their content was significantly higher than that of SAMR1 or age-matched ddY control. Thus, it was cleared that SAMP8 brain has high tendency to be attacked by endogenously produced oxygen radicals, possibly from its birth. Both IPBN and Cu-ATSM showed significantly higher accumulation in the SAMP8 brain than in the SAMR1 brain, indicating that these agents have high possibility for the early detection of abnormal brain aging as a radical-related disease.

Fujibayashi, Y.; Yamamoto, S.; Waki, A. [Fukui Medical School (Japan)]|[Kyoto Univ. (Japan)] [and others

1996-05-01

64

Neuromagnetic Abnormality of Motor Cortical Activation and Phases of Headache Attacks in Childhood Migraine  

PubMed Central

The cerebral cortex serves a primary role in the pathogenesis of migraine. This aberrant brain activation in migraine can be noninvasively detected with magnetoencephalography (MEG). The objective of this study was to investigate the differences in motor cortical activation between attacks (ictal) and pain free intervals (interictal) in children and adolescents with migraine using both low- and high-frequency neuromagnetic signals. Thirty subjects with an acute migraine and 30 subjects with a history of migraine, while pain free, were compared to age- and gender-matched controls using MEG. Motor cortical activation was elicited by a standardized, validated finger-tapping task. Low-frequency brain activation (1?50 Hz) was analyzed with waveform measurements and high-frequency oscillations (65–150 Hz) were analyzed with wavelet-based beamforming. MEG waveforms showed that the ictal latency of low-frequency brain activation was significantly delayed as compared with controls, while the interictal latency of brain activation was similar to that of controls. The ictal amplitude of low-frequency brain activation was significantly increased as compared with controls, while the interictal amplitude of brain activation was similar to that of controls. The ictal source power of high-frequency oscillations was significantly stronger than that of the controls, while the interictal source power of high-frequency oscillations was significantly weaker than that of controls. The results suggest that aberrant low-frequency brain activation in migraine during a headache attack returned to normal interictally. However, high-frequency oscillations changed from ictal hyper-activation to interictal hypo-activation. Noninvasive assessment of cortical abnormality in migraine with MEG opens a new window for developing novel therapeutic strategies for childhood migraine by maintaining a balanced cortical excitability. PMID:24386250

Xiang, Jing; deGrauw, Xinyao; Korman, Abraham M.; Allen, Janelle R.; O'Brien, Hope L.; Kabbouche, Marielle A.; Powers, Scott W.; Hershey, Andrew D.

2013-01-01

65

Gray Matter Abnormalities in Pediatric Mild Traumatic Brain Injury.  

PubMed

Pediatric mild traumatic brain injury (pmTBI) is the most prevalent neurological insult in children and is associated with both acute and chronic neuropsychiatric sequelae. However, little is known about underlying pathophysiology changes in gray matter diffusion and atrophy from a prospective stand-point. Fifteen semi-acute pmTBI patients and 15 well matched healthy controls were evaluated with a clinical and neuroimaging battery, with a subset of participants returning for a second visit. Clinical measures included tests of attention, processing speed, executive function, working memory, memory and self-reported post-concussive symptoms. Measures of diffusion (fractional anisotropy (FA)) and atrophy were also obtained for cortical and subcortical gray matter structures to characterize effects of injury as a function of time. Patients exhibited decreased scores in the domains of attention and processing speed relative to controls during the semi-acute injury stage, in conjunction with increased anisotropic diffusion in the left superior temporal gyrus and right thalamus. Evidence of increased diffusion in these regions was also present at 4 months post injury, with performance on cognitive tests partially normalizing. In contrast, signs of cortical atrophy in bilateral frontal areas and other left-hemisphere cortical areas only emerged at 4 months post-injury for patients. Current results suggest potentially differential time-courses of recovery for neurobehavioral markers, anisotropic diffusion and atrophy following pmTBI. Importantly, these data suggest that relying on patient self-report or standard clinical assessments may underestimate the time for true injury recovery. PMID:25313896

Mayer, Andrew; Hanlon, Faith M; Ling, Josef

2014-10-14

66

Diffusion Tensor Imaging of Brain Abnormalities Induced by Prenatal Exposure to Radiation in Rodents  

PubMed Central

We assessed brain abnormalities in rats exposed prenatally to radiation (X-rays) using magnetic resonance imaging (MRI) and histological experiments. Pregnant rats were divided into 4 groups: the control group (n?=?3) and 3 groups that were exposed to different radiation doses (0.5, 1.0, or 1.5 Gy; n?=?3 each). Brain abnormalities were assessed in 32 neonatal male rats (8 per group). Ex vivo T2-weighted imaging and diffusion tensor imaging (DTI) were performed using 11.7-T MRI. The expression of markers of myelin production (Kluver–Barrera staining, KB), nonpyramidal cells (calbindin-D28k staining, CaBP), and pyramidal cells (staining of the nonphosphorylated heavy-chain neurofilament SMI-32) were histologically evaluated. Decreased brain volume, increased ventricle volume, and thinner cortices were observed by MRI in irradiated rats. However, no abnormalities in the cortical 6-layered structure were observed via KB staining in radiation-exposed rats. The DTI color-coded map revealed a dose-dependent reduction in the anisotropic signal (vertical direction), which did not represent reduced numbers of pyramidal cells; rather, it indicated a signal reduction relative to the vertical direction because of low nerve cell density in the entire cortex. We conclude that DTI and histological experiments are useful tools for assessing cortical and hippocampal abnormalities after prenatal exposure to radiation in rats. PMID:25202992

Saito, Shigeyoshi; Sawada, Kazuhiko; Hirose, Miwa; Mori, Yuki; Yoshioka, Yoshichika; Murase, Kenya

2014-01-01

67

Blood-Brain Barrier Abnormalities in Vulnerable Brain Regions during Thiamine Deficiency  

Microsoft Academic Search

Experimental thiamine deficiency (TD) is a classical model of metabolic encephalopathy and selective cell loss in the brain resulting from a generalized, low-grade oxidative deficit. Late stages of TD are characterized by hemorrhages in the brain indicating a disruption of the blood-brain barrier (BBB). However, the relation of the breakdown of the BBB to selective cell loss in TD is

Noel Y. Calingasan; Harriet Baker; Kwan-Fu Rex Sheu; Gary E. Gibson

1995-01-01

68

Cranial index of children with normal and abnormal brain development in Sokoto, Nigeria: A comparative study  

PubMed Central

Background: Abnormal brain development due to neurodevelopmental disorders in children has always been an important concern, but yet has to be considered as a significant public health problem, especially in the low- and middle-income countries including Nigeria. Aims: The aim of this study is to determine whether abnormal brain development in the form of neurodevelopmental disorders causes any deviation in the cranial index of affected children. Materials and Methods: This is a comparative study on the head length, head width, and cranial index of 112 children (72 males and 40 females) diagnosed with at least one abnormal problem in brain development, in the form of a neurodevelopmental disorder (NDD), in comparison with that of 218 normal growing children without any form of NDD (121 males and 97 females), aged 0-18 years old seen at the Usmanu Danfodiyo University Teaching Hospital, Sokoto, over a period of six months, June to December, 2012. The head length and head width of the children was measured using standard anatomical landmarks and cranial index calculated. The data obtained was entered into the Microsoft excel worksheet and analyzed using SPSS version 17. Results: The mean Cephalic Index for normal growing children with normal brain development was 79.82 ± 3.35 and that of the children with abnormal brain development was 77.78 ± 2.95 and the difference between the two groups was not statistically significant (P > 0.05). Conclusion: It can be deduced from this present study that the cranial index does not change in children with neurodevelopmental disorders. PMID:24966551

Musa, Muhammad Awwal; Zagga, Abdullahi Daudu; Danfulani, Mohammed; Tadros, Aziz Abdo; Ahmed, Hamid

2014-01-01

69

Fueling and imaging brain activation  

PubMed Central

Metabolic signals are used for imaging and spectroscopic studies of brain function and disease and to elucidate the cellular basis of neuroenergetics. The major fuel for activated neurons and the models for neuron–astrocyte interactions have been controversial because discordant results are obtained in different experimental systems, some of which do not correspond to adult brain. In rats, the infrastructure to support the high energetic demands of adult brain is acquired during postnatal development and matures after weaning. The brain's capacity to supply and metabolize glucose and oxygen exceeds demand over a wide range of rates, and the hyperaemic response to functional activation is rapid. Oxidative metabolism provides most ATP, but glycolysis is frequently preferentially up-regulated during activation. Underestimation of glucose utilization rates with labelled glucose arises from increased lactate production, lactate diffusion via transporters and astrocytic gap junctions, and lactate release to blood and perivascular drainage. Increased pentose shunt pathway flux also causes label loss from C1 of glucose. Glucose analogues are used to assay cellular activities, but interpretation of results is uncertain due to insufficient characterization of transport and phosphorylation kinetics. Brain activation in subjects with low blood-lactate levels causes a brain-to-blood lactate gradient, with rapid lactate release. In contrast, lactate flooding of brain during physical activity or infusion provides an opportunistic, supplemental fuel. Available evidence indicates that lactate shuttling coupled to its local oxidation during activation is a small fraction of glucose oxidation. Developmental, experimental, and physiological context is critical for interpretation of metabolic studies in terms of theoretical models. PMID:22612861

Dienel, Gerald A

2012-01-01

70

A mechanical model predicts morphological abnormalities in the developing human brain  

NASA Astrophysics Data System (ADS)

The developing human brain remains one of the few unsolved mysteries of science. Advancements in developmental biology, neuroscience, and medical imaging have brought us closer than ever to understand brain development in health and disease. However, the precise role of mechanics throughout this process remains underestimated and poorly understood. Here we show that mechanical stretch plays a crucial role in brain development. Using the nonlinear field theories of mechanics supplemented by the theory of finite growth, we model the human brain as a living system with a morphogenetically growing outer surface and a stretch-driven growing inner core. This approach seamlessly integrates the two popular but competing hypotheses for cortical folding: axonal tension and differential growth. We calibrate our model using magnetic resonance images from very preterm neonates. Our model predicts that deviations in cortical growth and thickness induce morphological abnormalities. Using the gyrification index, the ratio between the total and exposed surface area, we demonstrate that these abnormalities agree with the classical pathologies of lissencephaly and polymicrogyria. Understanding the mechanisms of cortical folding in the developing human brain has direct implications in the diagnostics and treatment of neurological disorders, including epilepsy, schizophrenia, and autism.

Budday, Silvia; Raybaud, Charles; Kuhl, Ellen

2014-07-01

71

Mismatch negativity abnormality in traumatic brain injury without macroscopic lesions on conventional MRI.  

PubMed

Traumatic brain injury (TBI) causes damage through complex pathophysiological mechanisms. Deficits related to traumatic axonal injury persist in a subset of patients with no macroscopic lesions on conventional MRI. We examined two event-related brain potentials, mismatch negativity (MMN) and P3a, to identify possible electrophysiological anomalies in this subset of TBI patients in comparison with TBI patients with focal abnormalities on MRI/computed tomography and healthy controls. Each group consisted of 10 individuals. A passive oddball paradigm, in which the individuals were instructed to ignore auditory stimuli while watching a silent movie, consisted of non-native speech sounds presented in a random order. Patients with no discernible lesions on conventional MRI showed a significantly augmented amplitude of the brain's involuntary change-detection response MMN, relative to that of the two other groups. In patients with focal neuroradiological abnormalities, this MMN anomaly was not found, whereas the subsequent orientation-related P3a response was significantly enlarged when compared with that of the controls. The present findings demonstrate that MMN is indicative of a functional abnormality in the mechanisms of involuntary attention in chronic TBI patients with normal conventional MRI findings, indexing their increased distractibility associated with the traumatically-induced loss of neural integrity. PMID:23604169

Kaipio, Marja-Liisa; Cheour, Marie; Ohman, Juha; Salonen, Oili; Näätänen, Risto

2013-05-29

72

Morphometric abnormalities in brains of great blue heron hatchlings exposed in the wild to PCDDs.  

PubMed Central

Great blue heron hatchlings from colonies in the Strait of Georgia, British Columbia, Canada are being monitored for environmental contaminant exposure and effects by the Canadian Wildlife Service. The contaminants of concern are polychlorinated dibenzodioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs), primarily derived from kraft pulp mill effluent. The levels of PCDDs and PCDFs in eggs from the most contaminated colonies peaked in 1988 and 1989 and dropped dramatically through 1990 to 1992. Brains of heron hatchlings (taken as eggs from the wild and hatched in the laboratory) were analyzed for gross morphological abnormalities. Brains from highly contaminated colonies (Crofton, British Columbia and University of British Columbia Endowment Lands) in 1988 exhibited a high frequency of intercerebral asymmetry. The frequency of this abnormality decreased in subsequent years as the levels of TCDD and TCDD-TEQs (toxic equivalence factors) decreased. The asymmetry was significantly correlated with the level of TCDD and TCDD-TEQs in eggs taken from the same nest. Yolk-free body weight negatively correlated and the brain somatic index positively correlated with the TCDD level in such pair-matched eggs. These results indicate that gross brain morphology, and specifically intercerebral asymmetry, may be useful as a biomarker for the developmental neurotoxic effects of PCDDs and related chemicals. Images Figure 1. PMID:7556025

Henshel, D S; Martin, J W; Norstrom, R; Whitehead, P; Steeves, J D; Cheng, K M

1995-01-01

73

A Cross-Sectional Study of Regional Brain Volume Abnormalities in Lesch-Nyhan Disease and its Variants  

PubMed Central

Background Lesch-Nyhan disease (LND) is a rare, X-linked, neurodevelopmental metabolic disorder that results from a near-complete lack of hypoxanthine phosphoribosyl-transferase enzyme activity. LND is characterized by hyperuricemia, motor neurological abnormalities, recurrent self-injury, and cognitive impairment, but its neural substrates remain poorly understood. Methods In this cross-sectional study, we measured gray matter abnormalities in 21 persons with LND, 17 with an attenuated variant of the phenotype (LNV), and 33 healthy controls using voxel-based morphometry. We conducted an analysis of covariance to identify group differences in regional gray matter volume (GMV), followed by six pair-wise post-hoc group comparisons. Findings Patients with LND showed 20% smaller intracranial volumes (17% gray and 26% white matter) than healthy adults. The largest differences were found in basal ganglia, frontotemporal, and limbic regions, with sparing of parieto-occipital regions. The gray matter volumes of LNV participants invariably fell between those of patients with classical LND and healthy controls. Compared to healthy adults, patients with LND showed additional GMV reductions in the temporal lobe and left lateralized structures, and patients with LNV showed additional reductions in lingual and precuneus regions with sparing of right frontal and temporal regions. LND participants showed reductions in the ventral striatum and prefrontal areas relative to LNV. Interpretation This study of brain morphology reveals regional abnormalities associated with known neurological and behavioral deficits in persons with LND. It also revealed that patients with LNV show milder gray matter abnormalities in many of the same brain regions and preservation of GMV in other regions which could provide important clues to the neural substrates of differences between thephenotypes. PMID:24383089

Schretlen, David J.; Varvaris, Mark; Ho, Tiffany E.; Vannorsdall, Tracy D.; Gordon, Barry; Harris, James C.; Jinnah, H. A.

2014-01-01

74

Agrin in Alzheimer's Disease: Altered Solubility and Abnormal Distribution within Microvasculature and Brain Parenchyma  

NASA Astrophysics Data System (ADS)

Agrin is a heparan sulfate proteoglycan that is widely expressed in neurons and microvascular basal lamina in the rodent and avian central nervous system. Agrin induces the differentiation of nerve-muscle synapses, but its function in either normal or diseased brains is not known. Alzheimer's disease (AD) is characterized by loss of synapses, changes in microvascular architecture, and formation of neurofibrillary tangles and senile plaques. Here we have asked whether AD causes changes in the distribution and biochemical properties of agrin. Immunostaining of normal, aged human central nervous system revealed that agrin is expressed in neurons in multiple brain areas. Robust agrin immunoreactivity was observed uniformly in the microvascular basal lamina. In AD brains, agrin is highly concentrated in both diffuse and neuritic plaques as well as neurofibrillary tangles; neuronal expression of agrin also was observed. Furthermore, patients with AD had microvascular alterations characterized by thinning and fragmentation of the basal lamina. Detergent extraction and Western blotting showed that virtually all the agrin in normal brain is soluble in 1% SDS. In contrast, a large fraction of the agrin in AD brains is insoluble under these conditions, suggesting that it is tightly associated with ? -amyloid. Together, these data indicate that the agrin abnormalities observed in AD are closely linked to ? -amyloid deposition. These observations suggest that altered agrin expression in the microvasculature and the brain parenchyma contribute to the pathogenesis of AD.

Donahue, John E.; Berzin, Tyler M.; Rafii, Michael S.; Glass, David J.; Yancopoulos, George D.; Fallon, Justin R.; Stopa, Edward G.

1999-05-01

75

MRI Brain Volume Abnormalities in Young, Nonpsychotic Relatives of Schizophrenia Probands are Associated with Subsequent Prodromal Symptoms  

PubMed Central

Schizophrenia is characterized by subtle but well-replicated total and regional (frontal and temporal) brain tissue volume deficits. Studies of individuals at-risk for developing schizophrenia suggest that the onset of brain volume decrement may closely pre-date overt manifestations of schizophrenia, making brain volume abnormalities potential predictors for early identification. In an ongoing longitudinal morphometric MRI study of young, nonpsychotic first- or second-degree relatives of schizophrenia probands, we compared brain volumes in 46 relatives who are still within age range for developing schizophrenia against comparison groups of 46 schizophrenia patients and 46 healthy volunteers without family history of schizophrenia. Relatives had similar brain volume abnormalities as schizophrenia patients albeit less severe. Relatives had significantly larger whole brain, frontal, temporal and parietal gray matter (GM) volumes than patients. Relatives also had significantly smaller frontal GM volumes than healthy volunteers. Both relatives and patients had significantly larger whole brain WM (specifically parietal WM) volumes compared to healthy volunteers. Abnormally greater WM volumes in relatives and patients are suggestive of genetically-mediated dysmaturation of the age-expected myelination during adolescence through mid adulthood. On prodromal symptoms assessed in relatives one year after MRI brain scans, initial GM deficits as well as larger WM volumes correlated significantly with greater severity of subsequent prodromal symptoms. Together with previous genetic high-risk studies of adolescent or young adult relatives, these findings indicate that premorbid MRI brain abnormalities may be of predictive value for the early identification of schizophrenia. PMID:17761401

Ho, Beng-Choon

2007-01-01

76

Structural, Metabolic, and Functional Brain Abnormalities as a Result of Prenatal Exposure to Drugs of Abuse: Evidence from Neuroimaging  

PubMed Central

Prenatal exposure to alcohol and stimulants negatively affects the developing trajectory of the central nervous system in many ways. Recent advances in neuroimaging methods have allowed researchers to study the structural, metabolic, and functional abnormalities resulting from prenatal exposure to drugs of abuse in living human subjects. Here we review the neuroimaging literature of prenatal exposure to alcohol, cocaine, and methamphetamine. Neuroimaging studies of prenatal alcohol exposure have reported differences in the structure and metabolism of many brain systems, including in frontal, parietal, and temporal regions, in the cerebellum and basal ganglia, as well as in the white matter tracts that connect these brain regions. Functional imaging studies have identified significant differences in brain activation related to various cognitive domains as a result of prenatal alcohol exposure. The published literature of prenatal exposure to cocaine and methamphetamine is much smaller, but evidence is beginning to emerge suggesting that exposure to stimulant drugs in utero may be particularly toxic to dopamine-rich basal ganglia regions. Although the interpretation of such findings is somewhat limited by the problem of polysubstance abuse and by the difficulty of obtaining precise exposure histories in retrospective studies, such investigations provide important insights into the effects of drugs of abuse on the structure, function, and metabolism of the developing human brain. These insights may ultimately help clinicians develop better diagnostic tools and devise appropriate therapeutic interventions to improve the condition of children with prenatal exposure to drugs of abuse. PMID:20978945

Roussotte, Florence; Soderberg, Lindsay

2010-01-01

77

Motor Network Plasticity and Low-Frequency Oscillations Abnormalities in Patients with Brain Gliomas: A Functional MRI Study  

PubMed Central

Brain plasticity is often associated with the process of slow-growing tumor formation, which remodels neural organization and optimizes brain network function. In this study, we aimed to investigate whether motor function plasticity would display deficits in patients with slow-growing brain tumors located in or near motor areas, but who were without motor neurological deficits. We used resting-state functional magnetic resonance imaging to probe motor networks in 15 patients with histopathologically confirmed brain gliomas and 15 age-matched healthy controls. All subjects performed a motor task to help identify individual motor activity in the bilateral primary motor cortex (PMC) and supplementary motor area (SMA). Frequency-based analysis at three different frequencies was then used to investigate possible alterations in the power spectral density (PSD) of low-frequency oscillations. For each group, the average PSD was determined for each brain region and a nonparametric test was performed to determine the difference in power between the two groups. Significantly reduced inter-hemispheric functional connectivity between the left and right PMC was observed in patients compared with controls (P<0.05). We also found significantly decreased PSD in patients compared to that in controls, in all three frequency bands (low: 0.01–0.02 Hz; middle: 0.02–0.06 Hz; and high: 0.06–0.1 Hz), at three key motor regions. These findings suggest that in asymptomatic patients with brain tumors located in eloquent regions, inter-hemispheric connection may be more vulnerable. A comparison of the two approaches indicated that power spectral analysis is more sensitive than functional connectivity analysis for identifying the neurological abnormalities underlying motor function plasticity induced by slow-growing tumors. PMID:24806463

Niu, Chen; Zhang, Ming; Min, Zhigang; Rana, Netra; Zhang, Qiuli; Liu, Xin; Li, Min; Lin, Pan

2014-01-01

78

Abnormal Brain Connectivity Patterns in Adults with ADHD: A Coherence Study  

PubMed Central

Studies based on functional magnetic resonance imaging (fMRI) during the resting state have shown decreased functional connectivity between the dorsal anterior cingulate cortex (dACC) and regions of the Default Mode Network (DMN) in adult patients with Attention-Deficit/Hyperactivity Disorder (ADHD) relative to subjects with typical development (TD). Most studies used Pearson correlation coefficients among the BOLD signals from different brain regions to quantify functional connectivity. Since the Pearson correlation analysis only provides a limited description of functional connectivity, we investigated functional connectivity between the dACC and the posterior cingulate cortex (PCC) in three groups (adult patients with ADHD, n?=?21; TD age-matched subjects, n?=?21; young TD subjects, n?=?21) using a more comprehensive analytical approach – unsupervised machine learning using a one-class support vector machine (OC-SVM) that quantifies an abnormality index for each individual. The median abnormality index for patients with ADHD was greater than for TD age-matched subjects (p?=?0.014); the ADHD and young TD indices did not differ significantly (p?=?0.480); the median abnormality index of young TD was greater than that of TD age-matched subjects (p?=?0.016). Low frequencies below 0.05 Hz and around 0.20 Hz were the most relevant for discriminating between ADHD patients and TD age-matched controls and between the older and younger TD subjects. In addition, we validated our approach using the fMRI data of children publicly released by the ADHD-200 Competition, obtaining similar results. Our findings suggest that the abnormal coherence patterns observed in patients with ADHD in this study resemble the patterns observed in young typically developing subjects, which reinforces the hypothesis that ADHD is associated with brain maturation deficits. PMID:23049834

Sato, João Ricardo; Hoexter, Marcelo Queiroz; Castellanos, Xavier Francisco; Rohde, Luis A.

2012-01-01

79

Decoupling Neural Networks From Reality: Dissociative Experiences in Torture Victims Are Reflected in Abnormal Brain Waves in Left Frontal Cortex  

Microsoft Academic Search

From a neuroscience perspective, little is known about the long-term effect of torture. Dissociative experiences and posttraumatic stress disorder are often the results of this experience. We examined psychological dissociationwithinagroupof23torturevictimsandreport its manifestations within neural networks in the human brain. In particular, we observed that dissociative ex- periences are associated with slow abnormal brain waves generated in left ventrolateral frontal cortex.

William J. Ray; Michael Odenwald; Frank Neuner; Maggie Schauer; Martina Ruf; C. Wienbruch; B. Rockstroh; T. Elbert

2006-01-01

80

R6/2 Huntington’s disease Mice Develop Early and Progressive Abnormal Brain Metabolism and Seizures  

PubMed Central

A hallmark feature of Huntington's disease pathology is the atrophy of brain regions including, but not limited to, the striatum. Though MRI studies have identified structural CNS changes in several HD mouse models, the functional consequences of HD pathology during the progression of the disease have yet to be investigated using in vivo functional magnetic resonance imaging (fMRI). To address this issue, we first established the structural and functional MRI phenotype of juvenile HD mouse model R6/2 at early and advanced stages of disease. Significantly higher fMRI-signals (relative cerebral blood volumes-rCBV) and atrophy were observed in both age groups in specific brain regions. Next, fMRI results were correlated with electrophysiological analysis, which showed abnormal increases in neuronal activity in affected brain regions- thus identifying a mechanism accounting for the abnormal fMRI findings. [14C] deoxyglucose (2DG) maps to investigate patterns of glucose utilization were also generated. An interesting mismatch between increases in rCBV and decreases in glucose uptake was observed. Finally, we evaluated the sensitivity of this mouse line to audiogenic seizures early in the disease course. We found that R6/2 mice had an increased susceptibility to develop seizures. Together, these findings identified seizure activity in R6/2 mice, and show that neuroimaging measures sensitive to oxygen metabolism can be used as in vivo biomarkers, preceding the onset of an overt behavioral phenotype. Since fMRI-rCBV can also be obtained in patients, we propose that it may serve as a translational tool to evaluate therapeutic responses in humans and HD mouse models. PMID:22573668

Cepeda-Prado, E; Popp, S; Khan, U; Stefanov, D; Rodriguez, J; Menalled, L; Dow-Edwards, D; Small, SA; Moreno, H

2012-01-01

81

Neural activation abnormalities during self-referential processing in schizophrenia: an fMRI study.  

PubMed

Impairments in self-awareness contribute to disability in schizophrenia. Studies have revealed activation abnormalities in schizophrenia in cortical midline structures associated with self-reference. We used functional magnetic resonance imaging to compare activation throughout the brain in people with schizophrenia and healthy controls (Kelly et al., 2002) while they indicated whether trait adjectives described attributes of themselves, their mother or a former president of the United States. Blood oxygenation level dependent signal in each condition was compared to resting fixation. Patients were less likely and slower to endorse positive self-attributes, and more likely and quicker to endorse negative self-attributes than controls. Activation abnormalities reported previously in cortical midline structures were again noted. In addition, patients showed greater signal increases in frontal, temporal gyri and insula, and smaller signal decreases in posterior regions than healthy controls when thinking about themselves. Group differences were less evident when subjects were thinking about their mothers and tended to go in the opposite direction when thinking about a president. Many of the areas showing abnormality have been shown in other studies to differ between patients and controls in structure and with other activation paradigms. We suggest that general neuropathology in schizophrenia alters the neural system configurations associated with self-representation. PMID:24795158

Liu, Jiacheng; Corbera, Silvia; Wexler, Bruce Edward

2014-06-30

82

Cerebral abnormalities in cocaine abusers: Demonstration by SPECT perfusion brain scintigraphy. Work in progress  

SciTech Connect

Single photon emission computed tomography (SPECT) perfusion brain scans with iodine-123 isopropyl iodoamphetamine (IMP) were obtained in 12 subjects who acknowledged using cocaine on a sporadic to a daily basis. The route of cocaine administration varied from nasal to intravenous. Concurrent abuse of other drugs was also reported. None of the patients were positive for human immunodeficiency virus. Brain scans demonstrated focal defects in 11 subjects, including seven who were asymptomatic, and no abnormality in one. Among the findings were scattered focal cortical deficits, which were seen in several patients and which ranged in severity from small and few to multiple and large, with a special predilection for the frontal and temporal lobes. No perfusion deficits were seen on I-123 SPECT images in five healthy volunteers. Focal alterations in cerebral perfusion are seen commonly in asymptomatic drug users, and these focal deficits are readily depicted by I-123 IMP SPECT.

Tumeh, S.S.; Nagel, J.S.; English, R.J.; Moore, M.; Holman, B.L. (Harvard Medical School, Boston, MA (USA))

1990-09-01

83

Retinal microvascular abnormalities and subclinical magnetic resonance imaging brain infarct: a prospective study  

PubMed Central

Silent brain infarct and white matter lesions are common radiological findings associated with the risk of clinical stroke and dementia; however, our understanding of their underlying pathophysiology and risk factors remains limited. This study aimed to determine whether assessment of retinal microvascular abnormalities could provide prognostic information regarding the risk of brain infarct and white matter lesions on magnetic resonance imaging. This study is based on a subset of 810 middle-aged persons without clinical stroke or baseline magnetic resonance imaging infarct enrolled in the Atherosclerosis Risk in Communities Brain Magnetic Resonance Imaging Study, a prospective, population-based study. Participants had a baseline magnetic resonance imaging brain examination and retinal photography in 1993–1995, and returned for a repeat magnetic resonance imaging examination in 2004–2006. Magnetic resonance images were graded for presence of any cerebral infarct, infarct with lacunar characteristics and white matter lesions according to standardized protocols. Retinal photographs were graded for presence of retinopathy lesions and retinal arteriolar abnormalities following a standardized protocol. Over a median follow-up of 10.5 years, 164 (20.2%) participants developed cerebral infarct, 131 (16.2%) developed lacunar infarct, 182 (24.2%) developed new white matter lesions and 49 (6.1%) had evidence of white matter lesion progression. After adjusting for age, gender, race, cardiovascular risk factors and carotid intima-media thickness, retinopathy was associated with incident cerebral infarct (odds ratio 2.82; 95% confidence interval 1.42–5.60) and lacunar infarct (odds ratio 3.19; 95% confidence interval: 1.56–6.50). Retinal arteriovenous nicking was associated with incident cerebral infarct (odds ratio 2.82; 95% confidence interval: 1.66–4.76), lacunar infarct (odds ratio 2.48; 95% confidence interval: 1.39–4.40) and white matter lesion incidence (odds ratio 2.12; 95% confidence interval: 1.18–3.81) and progression (odds ratio 2.22; 95% confidence interval: 1.00–5.88). In conclusion, retinal microvascular abnormalities are associated with emergence of subclinical magnetic resonance imaging brain infarcts and white matter lesions, independent of shared risk factors. Retinal vascular imaging may offer a non-invasive tool to investigate the pathogenesis and natural history of cerebral small-vessel disease. PMID:20519327

Cheung, Ning; Mosley, Thomas; Islam, Amirul; Kawasaki, Ryo; Sharrett, A. Richey; Klein, Ronald; Coker, Laura H.; Knopman, David S.; Shibata, Dean K.; Catellier, Diane

2010-01-01

84

Abnormal brain maturation in preterm neonates associated with adverse developmental outcomes  

PubMed Central

Objective: Our objective was to determine the association of early brain maturation with neurodevelopmental outcome in premature neonates. Methods: Neonates born between 24 and 32 weeks’ gestation (April 2006 to August 2010) were prospectively studied with MRI early in life and again at term-equivalent age. Using diffusion tensor imaging and magnetic resonance spectroscopic imaging, fractional anisotropy (FA) (microstructure) and N-acetylaspartate (NAA)/choline (metabolism) were measured from the basal nuclei, white matter tracts, and superior white matter. Brain maturation is characterized by increasing FA and NAA/choline from early in life to term-equivalent age. In premature neonates, systemic illness and critical care therapies have been linked to abnormalities of these measures. Of the 177 neonates in this cohort, 5 died and 157 (91% of survivors) were assessed at 18 months’ corrected age (adjusted for prematurity) using the Bayley Scales of Infant and Toddler Development III motor, cognitive, and language composite scores (mean = 100, SD = 15). Results: Among these 157 infants, white matter injury was seen in 48 (30%). Severe white matter injury, in 10 neonates (6%), was associated with a decrease in motor (?18 points; p < 0.001) and cognitive (?8 points; p = 0.085) scores. With greater severity of adverse neurodevelopmental outcomes, slower increases in FA and NAA/choline were observed in the basal nuclei and brain white matter regions as neonates matured to term-equivalent age, independent of the presence of white matter injury. Conclusions: In the preterm neonate, abnormal brain maturation evolves through the period of neonatal intensive care and is associated with adverse neurodevelopmental outcomes. PMID:24212394

Chau, Vann; Synnes, Anne; Grunau, Ruth E.; Poskitt, Kenneth J.; Brant, Rollin

2013-01-01

85

Delineation of candidate genes responsible for structural brain abnormalities in patients with terminal deletions of chromosome 6q27.  

PubMed

Patients with terminal deletions of chromosome 6q present with structural brain abnormalities including agenesis of corpus callosum, hydrocephalus, periventricular nodular heterotopia, and cerebellar malformations. The 6q27 region harbors genes that are important for the normal development of brain and delineation of a critical deletion region for structural brain abnormalities may lead to a better genotype-phenotype correlation. We conducted a detailed clinical and molecular characterization of seven unrelated patients with deletions involving chromosome 6q27. All patients had structural brain abnormalities. Using array comparative genomic hybridization, we mapped the size, extent, and genomic content of these deletions. The smallest region of overlap spans 1.7?Mb and contains DLL1, THBS2, PHF10, and C6orf70 (ERMARD) that are plausible candidates for the causation of structural brain abnormalities. Our study reiterates the importance of 6q27 region in normal development of brain and helps identify putative genes in causation of structural brain anomalies. PMID:24736736

Peddibhotla, Sirisha; Nagamani, Sandesh C S; Erez, Ayelet; Hunter, Jill V; Holder, J Lloyd; Carlin, Mary E; Bader, Patricia I; Perras, Helene M F; Allanson, Judith E; Newman, Leslie; Simpson, Gayle; Immken, LaDonna; Powell, Erin; Mohanty, Aaron; Kang, Sung-Hae L; Stankiewicz, Pawel; Bacino, Carlos A; Bi, Weimin; Patel, Ankita; Cheung, Sau W

2015-01-01

86

Effects of hyperbaric oxygen on eye tracking abnormalities in males after mild traumatic brain injury.  

PubMed

The effects of hyperbaric oxygen (HBO2) on eye movement abnormalities in 60 military servicemembers with at least one mild traumatic brain injury (TBI) from combat were examined in a single-center, randomized, double-blind, sham-controlled, prospective study at the Naval Medicine Operational Training Center. During the 10 wk of the study, each subject was delivered a series of 40, once a day, hyperbaric chamber compressions at a pressure of 2.0 atmospheres absolute (ATA). At each session, subjects breathed one of three preassigned oxygen fractions (10.5%, 75%, or 100%) for 1 h, resulting in an oxygen exposure equivalent to breathing either surface air, 100% oxygen at 1.5 ATA, or 100% oxygen at 2.0 ATA, respectively. Using a standardized, validated, computerized eye tracking protocol, fixation, saccades, and smooth pursuit eye movements were measured just prior to intervention and immediately postintervention. Between and within groups testing of pre- and postintervention means revealed no significant differences on eye movement abnormalities and no significant main effect for HBO2 at either 1.5 ATA or 2.0 ATA equivalent compared with the sham-control. This study demonstrated that neither 1.5 nor 2.0 ATA equivalent HBO2 had an effect on postconcussive eye movement abnormalities after mild TBI when compared with a sham-control. PMID:25436771

Cifu, David X; Hoke, Kathy W; Wetzel, Paul A; Wares, Joanna R; Gitchel, George; Carne, William

2014-01-01

87

Right Brain Activities to Improve Analytical Thinking.  

ERIC Educational Resources Information Center

Schools tend to have a built-in bias toward left brain activities (tasks that are linear and sequential in nature), so the introduction of right brain activities (functions related to music, rhythm, images, color, imagination, daydreaming, dimensions) brings a balance into the classroom and helps those students who may be right brain oriented. To…

Lynch, Marion E.

88

Elevated Id2 expression results in precocious neural stem cell depletion and abnormal brain development  

PubMed Central

Id2 is a helix-loop-helix (HLH) transcription factor essential for normal development and its expression is dysregulated in many human neurological conditions. Although it is speculated that elevated Id2 levels contribute to the pathogenesis of these disorders, it is unknown whether dysregulated Id2 expression is sufficient to perturb normal brain development or function. Here, we show that mice with elevated Id2 expression during embryonic stages develop microcephaly, and that females in particular are prone to generalized tonic-clonic seizures. Analyses of Id2 transgenic brains indicate that Id2 activity is highly cell context specific: elevated Id2 expression in naive NSCs in early neuroepithelium induces apoptosis and loss of NSCs and intermediate progenitors. Activation of Id2 in maturing neuroepithelium results in less severe phenotypes and is accompanied by elevation of G1 Cyclin expression and p53 target gene expression. In contrast, activation of Id2 in committed intermediate progenitors has no significant phenotype. Functional analysis with Id2 over-expressing and Id2-null NSCs shows that Id2 negatively regulates NSC self-renewal in vivo, in contrast to previous cell culture experiments. Deletion of p53 function from Id2-transgenic brains rescues apoptosis and results in increased incidence of brain tumors. Furthermore, Id2 over-expression normalizes the increased self-renewal of p53-null NSCs, suggesting that Id2 activates and modulates the p53 pathway in NSCs. Together, these data suggest that elevated Id2 expression in embryonic brains can cause deregulated NSC self-renewal, differentiation and survival that manifest in multiple neurological outcomes in mature brains, including microcephaly, seizures, and brain tumors. PMID:23390122

Park, H.J.; Hong, M.; Bronson, R.T.; Israel, M.A.; Frankel, W. N.; Yun, K.

2013-01-01

89

Decoding patterns of human brain activity.  

PubMed

Considerable information about mental states can be decoded from noninvasive measures of human brain activity. Analyses of brain activity patterns can reveal what a person is seeing, perceiving, attending to, or remembering. Moreover, multidimensional models can be used to investigate how the brain encodes complex visual scenes or abstract semantic information. Such feats of "brain reading" or "mind reading," though impressive, raise important conceptual, methodological, and ethical issues. What does successful decoding reveal about the cognitive functions performed by a brain region? How should brain signals be spatially selected and mathematically combined to ensure that decoding reflects inherent computations of the brain rather than those performed by the decoder? We highlight recent advances and describe how multivoxel pattern analysis can provide a window into mind-brain relationships with unprecedented specificity, when carefully applied. However, as brain-reading technology advances, issues of neuroethics and mental privacy will be important to consider. PMID:21943172

Tong, Frank; Pratte, Michael S

2012-01-01

90

Downstream targets of methyl CpG binding protein 2 and their abnormal expression in the frontal cortex of the human Rett syndrome brain  

E-print Network

Background: The Rett Syndrome (RTT) brain displays regional histopathology and volumetric reduction, with frontal cortex showing such abnormalities, whereas the occipital cortex is relatively less affected. Results: Using ...

Gibson, Joanne H

91

Working Memory Brain Activation Following Severe Traumatic Brain Injury  

Microsoft Academic Search

Functional magnetic resonance imaging (fMRI) has shown that brain activation during performance of working memory (WM) tasks under high memory loads is altered in adults with severe traumatic brain injury (TBI) relative to uninjured subjects (Perlstein et al., 2004; Scheibel et al., 2003). Our study attempted to equate TBI patients and orthopedically injured (OI) subjects on performance of an N-Back

Mary R. Newsome; Randall S. Scheibel; Joel L. Steinberg; Maya Troyanskaya; Rajkumar G. Sharma; Ronald A. Rauch; Xioaqi Li; Harvey S. Levin

2007-01-01

92

Detecting Botnet Activities Based on Abnormal DNS traffic  

E-print Network

IThe botnet is considered as a critical issue of the Internet due to its fast growing mechanism and affect. Recently, Botnets have utilized the DNS and query DNS server just like any legitimate hosts. In this case, it is difficult to distinguish between the legitimate DNS traffic and illegitimate DNS traffic. It is important to build a suitable solution for botnet detection in the DNS traffic and consequently protect the network from the malicious Botnets activities. In this paper, a simple mechanism is proposed to monitors the DNS traffic and detects the abnormal DNS traffic issued by the botnet based on the fact that botnets appear as a group of hosts periodically. The proposed mechanism is also able to classify the DNS traffic requested by group of hosts (group behavior) and single hosts (individual behavior), consequently detect the abnormal domain name issued by the malicious Botnets. Finally, the experimental results proved that the proposed mechanism is robust and able to classify DNS traffic, and effi...

Manasrah, Ahmed M; Abouabdalla, Omar Amer; Ramadass, Sureswaran

2009-01-01

93

Stanford study shows brain abnormalities in breast cancer patients treated with chemotherapy:  

Cancer.gov

A neuroimaging study from the Stanford University School of Medicine has found that when asked to perform certain tasks, women who have undergone chemotherapy for breast cancer had significantly less activation of a part of the brain known to play a critical role in planning, attention and memory than did breast cancer patients without such treatment, as well as healthy women.

94

A multi-scanner study of subcortical brain volume abnormalities in schizophrenia.  

PubMed

Schizophrenia patients show significant subcortical brain abnormalities. We examined these abnormalities using automated image analysis software and provide effect size estimates for prospective multi-scanner schizophrenia studies. Subcortical and intracranial volumes were obtained using FreeSurfer 5.0.0 from high-resolution structural imaging scans from 186 schizophrenia patients (mean age±S.D.=38.9±11.6, 78% males) and 176 demographically similar controls (mean age±S.D.=37.5±11.2, 72% males). Scans were acquired from seven 3-Tesla scanners. Univariate mixed model regression analyses compared between-group volume differences. Weighted mean effect sizes (and number of subjects needed for 80% power at ?=0.05) were computed based on the individual single site studies as well as on the overall multi-site study. Schizophrenia patients have significantly smaller intracranial, amygdala, and hippocampus volumes and larger lateral ventricle, putamen and pallidum volumes compared with healthy volunteers. Weighted mean effect sizes based on single site studies were generally larger than effect sizes computed based on analysis of the overall multi-site sample. Prospectively collected structural imaging data can be combined across sites to increase statistical power for meaningful group comparisons. Even when using similar scan protocols at each scanner, some between-site variance remains. The multi-scanner effect sizes provided by this study should help in the design of future multi-scanner schizophrenia imaging studies. PMID:24650452

van Erp, Theo G M; Greve, Douglas N; Rasmussen, Jerod; Turner, Jessica; Calhoun, Vince D; Young, Sarah; Mueller, Bryon; Brown, Gregory G; McCarthy, Gregory; Glover, Gary H; Lim, Kelvin O; Bustillo, Juan R; Belger, Aysenil; McEwen, Sarah; Voyvodic, James; Mathalon, Daniel H; Keator, David; Preda, Adrian; Nguyen, Dana; Ford, Judith M; Potkin, Steven G; Fbirn

2014-04-30

95

Sensory abnormalities in focal hand dystonia and non-invasive brain stimulation.  

PubMed

It has been proposed that synchronous and convergent afferent input arising from repetitive motor tasks may play an important role in driving the maladaptive cortical plasticity seen in focal hand dystonia (FHD). This hypothesis receives support from several sources. First, it has been reported that in subjects with FHD, paired associative stimulation produces an abnormal increase in corticospinal excitability, which was not confined to stimulated muscles. These findings provide support for the role of excessive plasticity in FHD. Second, the genetic contribution to the dystonias is increasingly recognized indicating that repetitive, stereotyped afferent inputs may lead to late-onset dystonia, such as FHD, more rapidly in genetically susceptible individuals. It can be postulated, according to the two factor hypothesis that dystonia is triggered and maintained by the concurrence of environmental factors such as repetitive training and subtle abnormal mechanisms of plasticity within somatosensory loop. In the present review, we examine the contribution of sensory-motor integration in the pathophysiology of primary dystonia. In addition, we will discuss the role of non-invasive brain stimulation as therapeutic approach in FHD. PMID:25538594

Quartarone, Angelo; Rizzo, Vincenzo; Terranova, Carmen; Milardi, Demetrio; Bruschetta, Daniele; Ghilardi, Maria Felice; Girlanda, Paolo

2014-01-01

96

Sensory Abnormalities in Focal Hand Dystonia and Non-Invasive Brain Stimulation  

PubMed Central

It has been proposed that synchronous and convergent afferent input arising from repetitive motor tasks may play an important role in driving the maladaptive cortical plasticity seen in focal hand dystonia (FHD). This hypothesis receives support from several sources. First, it has been reported that in subjects with FHD, paired associative stimulation produces an abnormal increase in corticospinal excitability, which was not confined to stimulated muscles. These findings provide support for the role of excessive plasticity in FHD. Second, the genetic contribution to the dystonias is increasingly recognized indicating that repetitive, stereotyped afferent inputs may lead to late-onset dystonia, such as FHD, more rapidly in genetically susceptible individuals. It can be postulated, according to the two factor hypothesis that dystonia is triggered and maintained by the concurrence of environmental factors such as repetitive training and subtle abnormal mechanisms of plasticity within somatosensory loop. In the present review, we examine the contribution of sensory-motor integration in the pathophysiology of primary dystonia. In addition, we will discuss the role of non-invasive brain stimulation as therapeutic approach in FHD.

Quartarone, Angelo; Rizzo, Vincenzo; Terranova, Carmen; Milardi, Demetrio; Bruschetta, Daniele; Ghilardi, Maria Felice; Girlanda, Paolo

2014-01-01

97

Abnormal B Lymphocyte Activation and Function in Systemic Sclerosis  

PubMed Central

Systemic sclerosis (SSc) is characterized by tissue fibrosis and autoimmunity. Although the pathogenic relationship between autoimmunity and clinical manifestations of SSc remains unknown, SSc patients display abnormal immune responses including the production of disease-specific autoantibodies. Previous studies have demonstrated that B cells play a critical role in systemic autoimmunity and disease expression through various functions such as induction of the activation of other immune cells in addition to autoantibody production. CD19 is a crucial regulator of B cell activation. Recent studies demonstrated that B cells from SSc patients showed an up-regulated CD19 signaling pathway that induced SSc-specific autoantibody production in SSc mouse models. CD19 transgenic mice lost tolerance for autoantigen and generated autoantibodies spontaneously. B cells from SSc patients exhibited an overexpression of CD19 that induced SSc-specific autoantibody production in transgenic mice. Moreover, SSc patients displayed intrinsic B cell abnormalities characterized by chronic hyper-reactivity of memory B cells, which was possibly due to CD19 overexpression. Similarly, B cells from a tight-skin mouse, a genetic model of SSc, showed augmented CD19 signaling. In bleomycin-induced SSc mouse models, endogenous ligands for toll-like receptor 4 induced by bleomycin stimulated B cells to produce various fibrogenic cytokines and autoantibodies. Remarkably, the loss of CD19 resulted in the inhibition of B cell hyper-reactivity and autoantibody production, which are associated with improvements in fibrosis and a parallel decrease in fibrogenic cytokine production by B cells. Taken together, the findings suggest that altered B cell function may result in tissue fibrosis as well as autoimmunity in SSc.

Sato, Shinichi

2015-01-01

98

Abnormalities in auditory efferent activities in children with selective mutism.  

PubMed

Two efferent feedback pathways to the auditory periphery may play a role in monitoring self-vocalization: the middle-ear acoustic reflex (MEAR) and the medial olivocochlear bundle (MOCB) reflex. Since most studies regarding the role of auditory efferent activity during self-vocalization were conducted in animals, human data are scarce. The working premise of the current study was that selective mutism (SM), a rare psychiatric disorder characterized by consistent failure to speak in specific social situations despite the ability to speak normally in other situations, may serve as a human model for studying the potential involvement of auditory efferent activity during self-vocalization. For this purpose, auditory efferent function was assessed in a group of 31 children with SM and compared to that of a group of 31 normally developing control children (mean age 8.9 and 8.8 years, respectively). All children exhibited normal hearing thresholds and type A tympanograms. MEAR and MOCB functions were evaluated by means of acoustic reflex thresholds and decay functions and the suppression of transient-evoked otoacoustic emissions, respectively. Auditory afferent function was tested by means of auditory brainstem responses (ABR). Results indicated a significantly higher proportion of children with abnormal MEAR and MOCB function in the SM group (58.6 and 38%, respectively) compared to controls (9.7 and 8%, respectively). The prevalence of abnormal MEAR and/or MOCB function was significantly higher in the SM group (71%) compared to controls (16%). Intact afferent function manifested in normal absolute and interpeak latencies of ABR components in all children. The finding of aberrant efferent auditory function in a large proportion of children with SM provides further support for the notion that MEAR and MOCB may play a significant role in the process of self-vocalization. PMID:24107432

Muchnik, Chava; Ari-Even Roth, Daphne; Hildesheimer, Minka; Arie, Miri; Bar-Haim, Yair; Henkin, Yael

2013-01-01

99

A prospective study of gray matter abnormalities in mild traumatic brain injury  

PubMed Central

Objective: To examine the underlying pathophysiology of mild traumatic brain injury through changes in gray matter diffusion and atrophy during the semiacute stage. Methods: Fifty patients and 50 sex-, age-, and education-matched controls were evaluated with a clinical and neuroimaging battery approximately 14 days postinjury, with 26 patients returning for follow-up 4 months postinjury. Clinical measures included tests of attention, processing speed, executive function, working memory, memory, and self-reported postconcussive symptoms. Measures of diffusion (fractional anisotropy [FA], mean diffusivity) and atrophy were obtained for cortical and subcortical structures to characterize effects of injury as a function of time. Results: Patients reported more cognitive, somatic, and emotional complaints during the semiacute injury phase, which were significantly reduced 4 months postinjury. Patients showed evidence of increased FA in the bilateral superior frontal cortex during the semiacute phase, with the left superior frontal cortex remaining elevated 4 months postinjury. There were no significant differences between patients and matched controls on neuropsychological testing or measures of gray matter atrophy/mean diffusivity at either time point. Conclusions: Increased cortical FA is largely consistent with an emerging animal literature of gray matter abnormalities after neuronal injury. Potential mechanistic explanations for increased FA include cytotoxic edema or reactive gliosis. In contrast, there was no evidence of cortical or subcortical atrophy in the current study, suggesting that frank neuronal or neuropil loss does not occur early in the chronic disease course for patients with typical mild traumatic brain injury. PMID:24259552

Ling, Josef M.; Klimaj, Stefan; Toulouse, Trent

2013-01-01

100

Cognitive impairment as marker of diffuse brain abnormalities in early relapsing remitting multiple sclerosis  

PubMed Central

Objectives: To establish the frequency of cognitive impairment in a population based sample of patients with recently diagnosed relapsing-remitting multiple sclerosis (RRMS), and to determine the relation between cognitive abnormalities and the extent of macroscopic and microscopic tissue damage revealed by magnetic resonance imaging (MRI) and magnetisation transfer (MT) imaging. Methods: 58 patients with RRMS consecutively diagnosed in the previous six months in Aquitaine and 70 healthy controls underwent a battery of neuropsychological tests. Lesion load and atrophy indices (brain parenchymal fraction and ventricular fraction) were measured on brain MRI. MT ratio (MTR) histograms were obtained from lesions, normal appearing white matter (NAWM), and normal appearing grey matter (NAGM). Gadolinium enhanced lesions were counted. Results: 44 RRMS patients could be individually matched with healthy controls for age, sex, and education. Patients performed worse in tests of verbal and spatial memory, attention, information processing speed, inhibition, and conceptualisation. Measures of attention and information processing speed were correlated with lesion load, mean NAWM MTR, and the peak location of the NAGM MTR histogram in the patients. Multivariate regression analysis showed that lesion load and mean NAWM MTR were among the MR indices that were most significantly associated with impairment of attention and information processing speed in these early RRMS cases. Conclusions: Cognitive impairment appears to be common in the early stages of RRMS, mainly affecting attention, information processing speed, memory, inhibition, and conceptualisation. The severity of these deficits reflects the extent of the lesions and the severity of tissue disorganisation outside lesions. PMID:15774439

Deloire, M; Salort, E; Bonnet, M; Arimone, Y; Boudineau, M; Amieva, H; Barroso, B; Ouallet, J; Pachai, C; Galliaud, E; Petry, K; Dousset, V; Fabrigoule, C; Brochet, B

2005-01-01

101

Predicting the Probability of Abnormal Stimulated Growth Hormone Response in Children After Radiotherapy for Brain Tumors  

SciTech Connect

Purpose: To develop a mathematical model utilizing more readily available measures than stimulation tests that identifies brain tumor survivors with high likelihood of abnormal growth hormone secretion after radiotherapy (RT), to avoid late recognition and a consequent delay in growth hormone replacement therapy. Methods and Materials: We analyzed 191 prospectively collected post-RT evaluations of peak growth hormone level (arginine tolerance/levodopa stimulation test), serum insulin-like growth factor 1 (IGF-1), IGF-binding protein 3, height, weight, growth velocity, and body mass index in 106 children and adolescents treated for ependymoma (n = 72), low-grade glioma (n = 28) or craniopharyngioma (n = 6), who had normal growth hormone levels before RT. Normal level in this study was defined as the peak growth hormone response to the stimulation test {>=}7 ng/mL. Results: Independent predictor variables identified by multivariate logistic regression with high statistical significance (p < 0.0001) included IGF-1 z score, weight z score, and hypothalamic dose. The developed predictive model demonstrated a strong discriminatory power with an area under the receiver operating characteristic curve of 0.883. At a potential cutoff point of probability of 0.3 the sensitivity was 80% and specificity 78%. Conclusions: Without unpleasant and expensive frequent stimulation tests, our model provides a quantitative approach to closely follow the growth hormone secretory capacity of brain tumor survivors. It allows identification of high-risk children for subsequent confirmatory tests and in-depth workup for diagnosis of growth hormone deficiency.

Hua Chiaho, E-mail: Chia-Ho.Hua@stjude.org [Department of Radiological Sciences, St. Jude Children's Research Hospital, Memphis, Tennessee (United States); Wu Shengjie [Department of Biostatistics, St. Jude Children's Research Hospital, Memphis, Tennessee (United States)] [Department of Biostatistics, St. Jude Children's Research Hospital, Memphis, Tennessee (United States); Chemaitilly, Wassim [Division of Endocrinology, Department of Pediatric Medicine, St. Jude Children's Research Hospital, Memphis, Tennessee (United States)] [Division of Endocrinology, Department of Pediatric Medicine, St. Jude Children's Research Hospital, Memphis, Tennessee (United States); Lukose, Renin C.; Merchant, Thomas E. [Department of Radiological Sciences, St. Jude Children's Research Hospital, Memphis, Tennessee (United States)] [Department of Radiological Sciences, St. Jude Children's Research Hospital, Memphis, Tennessee (United States)

2012-11-15

102

Autism Spectrum Disorder as Early Neurodevelopmental Disorder: Evidence from the Brain Imaging Abnormalities in 2-3 Years Old Toddlers  

ERIC Educational Resources Information Center

Autism spectrum disorder (ASD) is a complex neurodevelopmental condition that occurs within the first 3 years of life, which is marked by social skills and communication deficits along with stereotyped repetitive behavior. Although great efforts have been made to clarify the underlying neuroanatomical abnormalities and brain-behavior relationships…

Xiao, Zhou; Qiu, Ting; Ke, Xiaoyan; Xiao, Xiang; Xiao, Ting; Liang, Fengjing; Zou, Bing; Huang, Haiqing; Fang, Hui; Chu, Kangkang; Zhang, Jiuping; Liu, Yijun

2014-01-01

103

Cross-Sectional and Longitudinal Abnormalities in Brain Structure in Children with Severe Mood Dysregulation or Bipolar Disorder  

ERIC Educational Resources Information Center

Background: There is debate as to whether chronic irritability (operationalized as severe mood dysregulation, SMD) is a developmental form of bipolar disorder (BD). Although structural brain abnormalities in BD have been demonstrated, no study compares neuroanatomy among SMD, BD, and healthy volunteers (HV) either cross-sectionally or over time.…

Adleman, Nancy E.; Fromm, Stephen J.; Razdan, Varun; Kayser, Reilly; Dickstein, Daniel P.; Brotman, Melissa A.; Pine, Daniel S.; Leibenluft, Ellen

2012-01-01

104

What is Alzheimer's Disease? Alzheimer's disease is a form of brain degeneration in which abnormal particles called neurofibrillary  

E-print Network

What is Alzheimer's Disease? Alzheimer's disease is a form of brain degeneration in which abnormal fact and remember it 30 minutes, or a day later, a skill we refer to as "memory". Who Gets Alzheimer's disease? The two main categories of Alzheimer's disease (AD) are familial and sporadic. Familial Alzheimer

Contractor, Anis

105

Penicillin-induced epileptiform activity elevates focal brain temperature in anesthetized rats.  

PubMed

To elucidate a relationship between changes in focal brain temperature and severity of abnormal brain activity, epileptiform discharges and behavioral seizures were induced by Penicillin G in anesthetized rats, and focal brain-temperature was measured. Penicillin G was injected into the right primary sensorimotor cortex (400IU/?l). After the injection, epileptiform discharges induced a temperature increase gradually by 0.65±0.24°C. Moreover, when behavioral seizures were induced by reducing the anesthesia level, the temperature was raised by 0.26±0.22°C. These results suggest that elevation of the focal brain temperature is associated with the severity of epileptic activity. PMID:23665136

Tokiwa, Tatsuji; Inoue, Takao; Fujii, Masami; Ishizuka, Satoru; Aou, Shuji; Kida, Hiroyuki; Maruta, Yuichi; Yamakawa, Toshitaka; Nomura, Sadahiro; Suzuki, Michiyasu; Yamakawa, Takeshi

2013-08-01

106

Incidence of Brain Abnormalities Detected on Preoperative Brain MR Imaging and Their Effect on the Outcome of Cochlear Implantation in Children with Sensorineural Hearing Loss  

PubMed Central

The incidence of sensorineural hearing loss (SNHL) increased gradually in the past decades. High-resolution computed tomography (HRCT) and magnetic resonance (MR) imaging, as an important part of preimplantation evaluation for children with SNHL, could provide the detailed information about the inner ear, the vestibulocochlear nerve, and the brain, so as to select suitable candidate for cochlear implantation (CI). Brain abnormalities were not rare in the brain MR imaging of SNHL children; however, its influence on the effect of CI has not been clarified. After retrospectively analyzing the CT and MR imaging of 157 children with SNHL that accepted preoperative evaluation from June 2011 to February 2013 in our hospital and following them during a period of 14.09 ± 5.08 months, we found that the white matter change, which might be associated with the history of medical condition, was the most common brain abnormality. Usually CI was still beneficial to the children with brain abnormalities, and the short-term hearing improvement could be achieved. Further study with more patients and longer follow-up time was needed to confirm our results.

Xu, Xiao-Quan; Wu, Fei-Yun; Hu, Hao; Su, Guo-Yi; Shen, Jie

2015-01-01

107

Activity of phosphatidylethanolamine-N-methyltransferase in brain affected by Alzheimers disease  

Microsoft Academic Search

To determine whether phospholipid abnormality in Alzheimers disease is associated with modification of phosphatidylethanolamine-N-methyltransferase, the activity of the enzyme was analysed in the frontal and occipital cortex of the brain from patients with Alzheimers disease and from aged-matched control. The optimum pH for phosphatidylethanolamine-N-methyltransferase in human brain was 9.0. The enzyme activity was stimulated by detergent TWEEN 20 but inhibited

Z.-Z Guan; Y.-N Wang; K.-Q Xiao; P.-S Hu; J.-L Liu

1999-01-01

108

Neurological and behavioral abnormalities, ventricular dilatation, altered cellular functions, inflammation, and neuronal injury in brains of mice due to common, persistent, parasitic infection  

PubMed Central

Background Worldwide, approximately two billion people are chronically infected with Toxoplasma gondii with largely unknown consequences. Methods To better understand long-term effects and pathogenesis of this common, persistent brain infection, mice were infected at a time in human years equivalent to early to mid adulthood and studied 5–12 months later. Appearance, behavior, neurologic function and brain MRIs were studied. Additional analyses of pathogenesis included: correlation of brain weight and neurologic findings; histopathology focusing on brain regions; full genome microarrays; immunohistochemistry characterizing inflammatory cells; determination of presence of tachyzoites and bradyzoites; electron microscopy; and study of markers of inflammation in serum. Histopathology in genetically resistant mice and cytokine and NRAMP knockout mice, effects of inoculation of isolated parasites, and treatment with sulfadiazine or ?PD1 ligand were studied. Results Twelve months after infection, a time equivalent to middle to early elderly ages, mice had behavioral and neurological deficits, and brain MRIs showed mild to moderate ventricular dilatation. Lower brain weight correlated with greater magnitude of neurologic abnormalities and inflammation. Full genome microarrays of brains reflected inflammation causing neuronal damage (Gfap), effects on host cell protein processing (ubiquitin ligase), synapse remodeling (Complement 1q), and also increased expression of PD-1L (a ligand that allows persistent LCMV brain infection) and CD 36 (a fatty acid translocase and oxidized LDL receptor that mediates innate immune response to beta amyloid which is associated with pro-inflammation in Alzheimer's disease). Immunostaining detected no inflammation around intra-neuronal cysts, practically no free tachyzoites, and only rare bradyzoites. Nonetheless, there were perivascular, leptomeningeal inflammatory cells, particularly contiguous to the aqueduct of Sylvius and hippocampus, CD4+ and CD8+ T cells, and activated microglia in perivascular areas and brain parenchyma. Genetically resistant, chronically infected mice had substantially less inflammation. Conclusion In outbred mice, chronic, adult acquired T. gondii infection causes neurologic and behavioral abnormalities secondary to inflammation and loss of brain parenchyma. Perivascular inflammation is prominent particularly contiguous to the aqueduct of Sylvius and hippocampus. Even resistant mice have perivascular inflammation. This mouse model of chronic T. gondii infection raises questions of whether persistence of this parasite in brain can cause inflammation or neurodegeneration in genetically susceptible hosts. PMID:18947414

Hermes, Gretchen; Ajioka, James W; Kelly, Krystyna A; Mui, Ernest; Roberts, Fiona; Kasza, Kristen; Mayr, Thomas; Kirisits, Michael J; Wollmann, Robert; Ferguson, David JP; Roberts, Craig W; Hwang, Jong-Hee; Trendler, Toria; Kennan, Richard P; Suzuki, Yasuhiro; Reardon, Catherine; Hickey, William F; Chen, Lieping; McLeod, Rima

2008-01-01

109

BRAIN ABNORMALITIES IN YOUNG ADULTS AT GENETIC RISK FOR AUTOSOMAL DOMINANT ALZHEIMER’S DISEASE: A CROSS-SECTIONAL STUDY  

PubMed Central

Summary Background We previously detected functional brain imaging abnormalities in young adults at genetic risk for late-onset Alzheimer’s disease (AD). Here, we sought to characterize structural and functional magnetic resonance imaging (MRI), cerebrospinal fluid (CSF), and plasma biomarker abnormalities in young adults at risk for autosomal dominant early-onset AD. Biomarker measurements were characterized and compared in presenilin 1 (PSEN1) E280A mutation carriers and non-carriers from the world’s largest known autosomal dominant early-onset AD kindred, more than two decades before the carriers’ estimated median age of 44 at the onset of mild cognitive impairment (MCI) and before their estimated age of 28 at the onset of amyloid-? (A?) plaque deposition. Methods Biomarker data for this cross-sectional study were acquired in Antioquia, Colombia between July and August, 2010. Forty-four participants from the Colombian Alzheimer’s Prevention Initiative (API) Registry had structural MRIs, functional MRIs during associative memory encoding/novel viewing and control tasks, and cognitive assessments. They included 20 mutation carriers and 24 non-carriers, who were cognitively normal, 18-26 years old and matched for their gender, age, and educational level. Twenty of the participants, including 10 mutation carriers and 10 non-carriers, had lumbar punctures and venipunctures. Primary outcome measures included task-dependent hippocampal/parahippocampal activations and precuneus/posterior cingulate deactivations, regional gray matter reductions, CSF A?1-42, total tau and phospho-tau181 levels, and plasma A?1-42 levels and A?1-42/A?1-40 ratios. Structural and functional MRI data were compared using automated brain mapping algorithms and AD-related search regions. Cognitive and fluid biomarkers were compared using Mann-Whitney tests. Findings The mutation carrier and non-carrier groups did not differ significantly in their dementia ratings, neuropsychological test scores, or proportion of apolipoprotein E (APOE) ?4 carriers. Compared to the non-carriers, carriers had higher CSF A?1-42 levels (p=0·008), plasma A?1-42 levels (p=0·01), and plasma A?1-42/A?1-40 ratios (p=0·001), consistent with A?1-42 overproduction. They also had greater hippocampal/parahippocampal activations (as low as p=0·008, after correction for multiple comparisons), less precuneus/posterior cingulate deactivations (as low as p=0·001, after correction), less gray matter in several regions (p-values <0·005, uncorrected, and corrected p=0·008 in the parietal search region), similar to findings in the later preclinical and clinical stages of autosomal dominant and late-onset AD. Interpretation Young adults at genetic risk for autosomal dominant AD have functional and structural MRI abnormalities, along with CSF and plasma biomarker findings consistent with A?1-42 over-production. While the extent to which the underlying brain changes are progressive or developmental remain to be determined, this study demonstrates the earliest known biomarker changes in cognitively normal people at genetic risk for autosomal dominant AD. Funding Banner Alzheimer’s Foundation, Nomis Foundation, Anonymous Foundation, Forget Me Not Initiative, Boston University Department of Psychology, Colciencias (1115-408-20512, 1115-545-31651), National Institute on Aging (R01 AG031581, P30 AG19610, UO1 AG024904, RO1 AG025526, RF1AG041705), National Institute of Neurological Disorders and Stroke (F31-NS078786) and state of Arizona. PMID:23137948

Reiman, Eric M.; Quiroz, Yakeel T.; Fleisher, Adam S.; Chen, Kewei; Velez-Pardo, Carlos; Jimenez-Del-Rio, Marlene; Fagan, Anne M.; Shah, Aarti R.; Alvarez, Sergio; Arbelaez, Andrés; Giraldo, Margarita; Acosta-Baena, Natalia; Sperling, Reisa A.; Dickerson, Brad; Stern, Chantal E.; Tirado, Victoria; Munoz, Claudia; Reiman, Rebecca A.; Huentelman, Matthew J.; Alexander, Gene E.; Langbaum, Jessica B.S.; Kosik, Kenneth S.; Tariot, Pierre N.; Lopera, Francisco

2013-01-01

110

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

PubMed Central

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

2011-01-01

111

Active targeting of brain tumors using nanocarriers.  

PubMed

The delivery of drugs to brain tumors is limited by the presence of the blood-brain barrier (BBB) separating the blood from the cerebral parenchyma. An understanding of the specific mechanisms of the brain capillary endothelium has led to the development of various strategies to enhance the penetration of drugs into the brain tissue. Active targeting is a non-invasive approach, which consists in transporting drugs to target organs using site-specific ligands. Drug-loaded nanocarriers capable of recognizing brain capillary endothelial cells and cerebral tumoral cells have shown promising potential in oncology. Endogenous and chimeric ligands binding to carriers or receptors of the BBB have been directly or indirectly conjugated to nanocarriers. This review indexes the main targeted colloidal systems used for drug delivery to the brain. Their pharmacological behavior and their therapeutic effect are discussed. PMID:17716726

Béduneau, Arnaud; Saulnier, Patrick; Benoit, Jean-Pierre

2007-11-01

112

Abnormal electromyographic activity of the urethral sphincter, voiding dysfunction, and polycystic ovaries: a new syndrome?  

Microsoft Academic Search

A potential association between abnormal electromyographic activity--that is, decelerating bursts and complex repetitive discharges--of the urethral sphincter and difficulty in voiding was examined in 57 women with urinary retention. Abnormal electromyographic activity was found in 33. Ultrasonography of the ovaries in 22 of the 33 women showed that 14 had polycystic ovaries. Of the other eight women, two had had

C. J. Fowler; T. J. Christmas; C. R. Chapple; H. F. Parkhouse; R. S. Kirby; H. S. Jacobs

1988-01-01

113

Abnormal brain responses to social fairness in depression: an fMRI study using the Ultimatum Game.  

PubMed

Background. Depression is a prevalent disorder that significantly affects the social functioning and interpersonal relationships of individuals. This highlights the need for investigation of the neural mechanisms underlying these social difficulties. Investigation of social exchanges has traditionally been challenging as such interactions are difficult to quantify. Recently, however, neuroeconomic approaches that combine multiplayer behavioural economic paradigms and neuroimaging have provided a framework to operationalize and quantify the study of social interactions and the associated neural substrates. Method. We investigated brain activation using functional magnetic resonance imaging (fMRI) in unmedicated depressed participants (n = 25) and matched healthy controls (n = 25). During scanning, participants played a behavioural economic paradigm, the Ultimatum Game (UG). In this task, participants accept or reject monetary offers from other players. Results. In comparison to controls, depressed participants reported decreased levels of happiness in response to 'fair' offers. With increasing fairness of offers, controls activated the nucleus accumbens and the dorsal caudate, regions that have been reported to process social information and responses to rewards. By contrast, participants with depression failed to activate these regions with increasing fairness, with the lack of nucleus accumbens activation correlating with increased anhedonia symptoms. Depressed participants also showed a diminished response to increasing unfairness of offers in the medial occipital lobe. Conclusions. Our findings suggest that depressed individuals differ from healthy controls in the neural substrates involved with processing social information. In depression, the nucleus accumbens and dorsal caudate may underlie abnormalities in processing information linked to the fairness and rewarding aspects of other people's decisions. PMID:25277236

Gradin, V B; Pérez, A; MacFarlane, J A; Cavin, I; Waiter, G; Engelmann, J; Dritschel, B; Pomi, A; Matthews, K; Steele, J D

2014-10-01

114

Abnormal Spontaneous Neural Activity in Obsessive-Compulsive Disorder: A Resting-State Functional Magnetic Resonance Imaging Study  

PubMed Central

Neuroimaging studies of obsessive-compulsive disorder have found abnormalities in orbitofronto-striato-thalamic circuitry, including the orbitofrontal cortex, anterior cingulate cortex, caudate, and thalamus, but few studies have explored abnormal intrinsic or spontaneous brain activity in the resting state. We investigated both intra- and inter-regional synchronized activity in twenty patients with obsessive-compulsive disorder and 20 healthy controls using resting-state functional magnetic resonance imaging. Regional homogeneity (ReHo) and functional connectivity methods were used to analyze the intra- and inter-regional synchronized activity, respectively. Compared with healthy controls, patients with obsessive-compulsive disorder showed significantly increased ReHo in the orbitofrontal cortex, cerebellum, and insula, and decreased ReHo in the ventral anterior cingulate cortex, caudate, and inferior occipital cortex. Based on ReHo results, we determined functional connectivity differences between the orbitofrontal cortex and other brain regions in both patients with obsessive-compulsive disorder and controls. We found abnormal functional connectivity between the orbitofrontal cortex and ventral anterior cingulate cortex in patients with obsessive-compulsive disorder compared with healthy controls. Moreover, ReHo in the orbitofrontal cortex was correlated with the duration of obsessive-compulsive disorder. These findings suggest that increased intra- and inter-regional synchronized activity in the orbitofrontal cortex may have a key role in the pathology of obsessive-compulsive disorder. In addition to orbitofronto-striato-thalamic circuitry, brain regions such as the insula and cerebellum may also be involved in the pathophysiology of obsessive-compulsive disorder. PMID:23826251

Su-Fang, Li; Zhang-Ye, Dong; Jia, Luo; Zhi-Hua, Guo; Hong-Fang, Xiong; Yu-Feng, Zang; Zhan-Jiang, Li

2013-01-01

115

Dentate gyrus abnormalities in sudden unexplained death in infants: morphological marker of underlying brain vulnerability.  

PubMed

Sudden unexplained death in infants, including the sudden infant death syndrome, is likely due to heterogeneous causes that involve different intrinsic vulnerabilities and/or environmental factors. Neuropathologic research focuses upon the role of brain regions, particularly the brainstem, that regulate or modulate autonomic and respiratory control during sleep or transitions to waking. The hippocampus is a key component of the forebrain-limbic network that modulates autonomic/respiratory control via brainstem connections, but its role in sudden infant death has received little attention. We tested the hypothesis that a well-established marker of hippocampal pathology in temporal lobe epilepsy-focal granule cell bilamination in the dentate, a variant of granule cell dispersion-is associated with sudden unexplained death in infants. In a blinded study of hippocampal morphology in 153 infants with sudden and unexpected death autopsied in the San Diego County medical examiner's office, deaths were classified as unexplained or explained based upon autopsy and scene investigation. Focal granule cell bilamination was present in 41.2 % (47/114) of the unexplained group compared to 7.7 % (3/39) of the explained (control) group (p < 0.001). It was associated with a cluster of other dentate developmental abnormalities that reflect defective neuronal proliferation, migration, and/or survival. Dentate lesions in a large subset of infants with sudden unexplained death may represent a developmental vulnerability that leads to autonomic/respiratory instability or autonomic seizures, and sleep-related death when the infants are challenged with homeostatic stressors. Importantly, these lesions can be recognized in microscopic sections prepared in current forensic practice. Future research is needed to determine the relationship between hippocampal and previously reported brainstem pathology in sudden infant death. PMID:25421424

Kinney, Hannah C; Cryan, Jane B; Haynes, Robin L; Paterson, David S; Haas, Elisabeth A; Mena, Othon J; Minter, Megan; Journey, Kelley W; Trachtenberg, Felicia L; Goldstein, Richard D; Armstrong, Dawna D

2015-01-01

116

How study of respiratory physiology aided our understanding of abnormal brain function in panic disorder  

Microsoft Academic Search

There is a substantial body of literature demonstrating that stimulation of respiration (hyperventilation) is a common event in panic disorder patients during panic attack episodes. Further, a number of abnormalities in respiration, such as enhanced CO2 sensitivity, have been detected in panic patients. This led some to posit that there is a fundamental abnormality in the physiological mechanisms that control

Smit Sinha; Laszlo A Papp; Jack M Gorman

2000-01-01

117

The "normal" brain. "Abnormal" ubiquitinilated deposits highlight an age-related protein change.  

PubMed Central

Known morphologic changes that characterize "normal" brain senescence are insufficient to explain the widespread, age-related decline of psychomotor functions. We report that the heavily ubiquitinilated deposits can be consistently detected by immunohistochemistry in the normal senescent brain. Immunostaining of hippocampal sections from aged brains with an anti-ubiquitin antibody was unrelated to neurofibrillary degeneration or senile plaque formation. In contrast, ubiquitin deposits were not detectable in brain sections from neurologically and neuropathologically normal young individuals who had died of nonneurological causes. This finding shows an unrecognized protein change in the normal aged brain. Images Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 PMID:2552809

Pappolla, M. A.; Omar, R.; Saran, B.

1989-01-01

118

Nanotools for Neuroscience and Brain Activity Mapping  

PubMed Central

Neuroscience is at a crossroads. Great effort is being invested into deciphering specific neural interactions and circuits. At the same time, there exist few general theories or principles that explain brain function. We attribute this disparity, in part, to limitations in current methodologies. Traditional neurophysiological approaches record the activities of one neuron or a few neurons at a time. Neurochemical approaches focus on single neurotransmitters. Yet, there is an increasing realization that neural circuits operate at emergent levels, where the interactions between hundreds or thousands of neurons, utilizing multiple chemical transmitters, generate functional states. Brains function at the nanoscale, so tools to study brains must ultimately operate at this scale, as well. Nanoscience and nanotechnology are poised to provide a rich toolkit of novel methods to explore brain function by enabling simultaneous measurement and manipulation of activity of thousands or even millions of neurons. We and others refer to this goal as the Brain Activity Mapping Project. In this Nano Focus, we discuss how recent developments in nanoscale analysis tools and in the design and synthesis of nanomaterials have generated optical, electrical, and chemical methods that can readily be adapted for use in neuroscience. These approaches represent exciting areas of technical development and research. Moreover, unique opportunities exist for nanoscientists, nanotechnologists, and other physical scientists and engineers to contribute to tackling the challenging problems involved in understanding the fundamentals of brain function. PMID:23514423

Alivisatos, A. Paul; Andrews, Anne M.; Boyden, Edward S.; Chun, Miyoung; Church, George M.; Deisseroth, Karl; Donoghue, John P.; Fraser, Scott E.; Lippincott-Schwartz, Jennifer; Looger, Loren L.; Masmanidis, Sotiris; McEuen, Paul L.; Nurmikko, Arto V.; Park, Hongkun; Peterka, Darcy S.; Reid, Clay; Roukes, Michael L.; Scherer, Axel; Schnitzer, Mark; Sejnowski, Terrence J.; Shepard, Kenneth L.; Tsao, Doris; Turrigiano, Gina; Weiss, Paul S.; Xu, Chris; Yuste, Rafael; Zhuang, Xiaowei

2013-01-01

119

Abnormalities in brain structure and behavior in GSK-3alpha mutant mice  

PubMed Central

Background Glycogen synthase kinase-3 (GSK-3) is a widely expressed and highly conserved serine/threonine protein kinase encoded by two genes that generate two related proteins: GSK-3? and GSK-3?. Mice lacking a functional GSK-3? gene were engineered in our laboratory; they are viable and display insulin sensitivity. In this study, we have characterized brain functions of GSK-3? KO mice by using a well-established battery of behavioral tests together with neurochemical and neuroanatomical analysis. Results Similar to the previously described behaviours of GSK-3?+/-mice, GSK-3? mutants display decreased exploratory activity, decreased immobility time and reduced aggressive behavior. However, genetic inactivation of the GSK-3? gene was associated with: decreased locomotion and impaired motor coordination, increased grooming activity, loss of social motivation and novelty; enhanced sensorimotor gating and impaired associated memory and coordination. GSK-3? KO mice exhibited a deficit in fear conditioning, however memory formation as assessed by a passive avoidance test was normal, suggesting that the animals are sensitized for active avoidance of a highly aversive stimulus in the fear-conditioning paradigm. Changes in cerebellar structure and function were observed in mutant mice along with a significant decrease of the number and size of Purkinje cells. Conclusion Taken together, these data support a role for the GSK-3? gene in CNS functioning and possible involvement in the development of psychiatric disorders. PMID:19925672

2009-01-01

120

Brain structural abnormalities in behavior therapy-resistant obsessive-compulsive disorder revealed by voxel-based morphometry  

PubMed Central

Background Although several functional imaging studies have demonstrated that behavior therapy (BT) modifies the neural circuits involved in the pathogenesis of obsessive-compulsive disorder (OCD), the structural abnormalities underlying BT-resistant OCD remain unknown. Methods In this study, we examined the existence of regional structural abnormalities in both the gray matter and the white matter of patients with OCD at baseline using voxel-based morphometry in responders (n=24) and nonresponders (n=15) to subsequent BT. Three-dimensional T1-weighted magnetic resonance imaging was performed before the completion of 12 weeks of BT. Results Relative to the responders, the nonresponders exhibited significantly smaller gray matter volumes in the right ventromedial prefrontal cortex, the right orbitofrontal cortex, the right precentral gyrus, and the left anterior cingulate cortex. In addition, relative to the responders, the nonresponders exhibited significantly smaller white matter volumes in the left cingulate bundle and the left superior frontal white matter. Conclusion These results suggest that the brain structures in several areas, including the orbitofrontal cortex, anterior cingulate cortex, and cingulate bundles, are related to the lack of a response to BT in patients with OCD. The use of a voxel-based morphometry approach may be advantageous to understanding differences in brain abnormalities between responders and nonresponders to BT. PMID:25349476

Hashimoto, Nobuhiko; Nakaaki, Shutaro; Kawaguchi, Akiko; Sato, Junko; Kasai, Harumasa; Nakamae, Takashi; Narumoto, Jin; Miyata, Jun; Furukawa, Toshi A; Mimura, Masaru

2014-01-01

121

Brain activation in patients with idiopathic hyperacusis  

Microsoft Academic Search

The neural network associated with idiopathic hyperacusis is still not well known. We studied the brain activation of 3 middle-aged patients with mild to moderate hyperacusis by functional magnetic resonance imaging while they were listening to white noise binaurally. In addition to the temporal lobes, in all patients, sound elicited activation in the frontal lobes (superior, middle, or inferior frontal

Juen-Haur Hwang; Pao-Hsuan Chou; Chang-Wei Wu; Jyh-Horng Chen; Tien-Chen Liu

2009-01-01

122

Heritability of working memory brain activation.  

PubMed

Although key to understanding individual variation in task-related brain activation, the genetic contribution to these individual differences remains largely unknown. Here we report voxel-by-voxel genetic model fitting in a large sample of 319 healthy, young adult, human identical and fraternal twins (mean ± SD age, 23.6 ± 1.8 years) who performed an n-back working memory task during functional magnetic resonance imaging (fMRI) at a high magnetic field (4 tesla). Patterns of task-related brain response (BOLD signal difference of 2-back minus 0-back) were significantly heritable, with the highest estimates (40-65%) in the inferior, middle, and superior frontal gyri, left supplementary motor area, precentral and postcentral gyri, middle cingulate cortex, superior medial gyrus, angular gyrus, superior parietal lobule, including precuneus, and superior occipital gyri. Furthermore, high test-retest reliability for a subsample of 40 twins indicates that nongenetic variance in the fMRI brain response is largely due to unique environmental influences rather than measurement error. Individual variations in activation of the working memory network are therefore significantly influenced by genetic factors. By establishing the heritability of cognitive brain function in a large sample that affords good statistical power, and using voxel-by-voxel analyses, this study provides the necessary evidence for task-related brain activation to be considered as an endophenotype for psychiatric or neurological disorders, and represents a substantial new contribution to the field of neuroimaging genetics. These genetic brain maps should facilitate discovery of gene variants influencing cognitive brain function through genome-wide association studies, potentially opening up new avenues in the treatment of brain disorders. PMID:21795540

Blokland, Gabriëlla A M; McMahon, Katie L; Thompson, Paul M; Martin, Nicholas G; de Zubicaray, Greig I; Wright, Margaret J

2011-07-27

123

Distribution of neurochemical abnormalities in patients with narcolepsy with cataplexy: An in vivo brain proton MR spectroscopy study.  

PubMed

Narcolepsy with cataplexy is characterised by excessive daytime sleepiness, sudden drops of muscle tone triggered by emotions, termed cataplexy, disrupted nocturnal sleep and other dissociated rapid eye movement (REM) sleep phenomena. Narcolepsy has been linked to a loss of hypothalamic neurons producing hypocretins, neuropeptides implicated in the regulation of the arousal system. Neuroimaging and neurometabolic studies have shown the pathophysiological involvement of other brain structures such as cerebral cortex and thalamus, but, overall with inconsistent results. We investigated, by using an advanced quantitative MR technique, proton MR spectroscopy ((1)H-MRS), the distribution of brain neurochemical abnormalities in narcolepsy with cataplexy patients. Single voxel (1)H-MRS study was performed in the thalamus, hypothalamus, and parietal-occipital cortex of hypocretin deficient, narcolepsy with cataplexy patients, HLA-DQB1*0602-positive, drug free. No significant changes were detected in the thalamus and parietal-occipital cortex of the patients. On the other hand, the neuronal marker N-acetyl-aspartate was reduced in the hypothalamus of narcolepsy with cataplexy patients compared to controls. These (1)H-MRS findings further support that in narcolepsy with cataplexy patients, the hypothalamus is the primary site of neural lesions. The absence of (1)H-MRS neurodegenerative changes in the thalamus and cerebral cortex suggests that the abnormalities detected in these brain regions by other neuroimaging techniques are likely of functional nature. PMID:19463917

Tonon, Caterina; Franceschini, Christian; Testa, Claudia; Manners, David Neil; Poli, Francesca; Mostacci, Barbara; Mignot, Emanuel; Montagna, Pasquale; Barbiroli, Bruno; Lodi, Raffaele; Plazzi, Giuseppe

2009-09-28

124

Autism spectrum disorder as early neurodevelopmental disorder: evidence from the brain imaging abnormalities in 2-3 years old toddlers.  

PubMed

Autism spectrum disorder (ASD) is a complex neurodevelopmental condition that occurs within the first 3 years of life, which is marked by social skills and communication deficits along with stereotyped repetitive behavior. Although great efforts have been made to clarify the underlying neuroanatomical abnormalities and brain-behavior relationships in adolescents and adults with ASD, literature is still limited in information about the neurobiology of ASD in the early age of life. Brain images of 50 toddlers with ASD and 28 age, gender, and developmental quotient matched toddlers with developmental delay (DD) (control group) between ages 2 and 3 years were captured using combined magnetic resonance-based structural imaging and diffusion tensor imaging (DTI). Structural magnetic resonance imaging was applied to assess overall gray matter (GM) and white matter (WM) volumes, and regional alterations were assessed by voxel-based morphometry. DTI was used to investigate the white matter tract integrity. Compared with DD, significant increases were observed in ASD, primarily in global GM and WM volumes and in right superior temporal gyrus regional GM and WM volumes. Higher fractional anisotropy value was also observed in the corpus callosum, posterior cingulate cortex, and limbic lobes of ASD. The converging findings of structural and white matter abnormalities in ASD suggest that alterations in neural-anatomy of different brain regions may be involved in behavioral and cognitive deficits associated with ASD, especially in an early age of 2-3 years old toddlers. PMID:24419870

Xiao, Zhou; Qiu, Ting; Ke, Xiaoyan; Xiao, Xiang; Xiao, Ting; Liang, Fengjing; Zou, Bing; Huang, Haiqing; Fang, Hui; Chu, Kangkang; Zhang, Jiuping; Liu, Yijun

2014-07-01

125

Characterization of Subtle Brain Abnormalities in a Mouse Model of Hedgehog Pathway Antagonist-Induced Cleft Lip and Palate  

PubMed Central

Subtle behavioral and cognitive deficits have been documented in patient cohorts with orofacial clefts (OFCs). Recent neuroimaging studies argue that these traits are associated with structural brain abnormalities but have been limited to adolescent and adult populations where brain plasticity during infancy and childhood may be a confounding factor. Here, we employed high resolution magnetic resonance microscopy to examine primary brain morphology in a mouse model of OFCs. Transient in utero exposure to the Hedgehog (Hh) signaling pathway antagonist cyclopamine resulted in a spectrum of facial dysmorphology, including unilateral and bilateral cleft lip and palate, cleft of the secondary palate only, and a non-cleft phenotype marked by midfacial hypoplasia. Relative to controls, cyclopamine-exposed fetuses exhibited volumetric differences in several brain regions, including hypoplasia of the pituitary gland and olfactory bulbs, hyperplasia of the forebrain septal region, and expansion of the third ventricle. However, in affected fetuses the corpus callosum was intact and normal division of the forebrain was observed. This argues that temporally-specific Hh signaling perturbation can result in typical appearing OFCs in the absence of holoprosencephaly—a condition classically associated with Hh pathway inhibition and frequently co-occurring with OFCs. Supporting the premise that some forms of OFCs co-occur with subtle brain malformations, these results provide a possible ontological basis for traits identified in clinical populations. They also argue in favor of future investigations into genetic and/or environmental modulation of the Hh pathway in the etiopathogenesis of orofacial clefting. PMID:25047453

Lipinski, Robert J.; Holloway, Hunter T.; O'Leary-Moore, Shonagh K.; Ament, Jacob J.; Pecevich, Stephen J.; Cofer, Gary P.; Budin, Francois; Everson, Joshua L.; Johnson, G. Allan; Sulik, Kathleen K.

2014-01-01

126

Prenatal-postnatal correlations of brain abnormalities: how lesions and diagnoses change over time  

PubMed Central

A combination of prenatal ultrasound and MRI can be used to detect and characterize many primary and secondary CNS abnormalities in the developing fetus. While this information is useful in prenatal patient counseling, it is important to understand the factors that can influence change in diagnosis and prognosis over time. The etiology of the abnormality, the conspicuity of associated findings, the change in appearance over time, and the opinion of subspecialty experts all can influence the diagnosis. Additionally, technical factors of imaging acquisition may allow the detection of an abnormality in the postnatal period and not prenatally. Having an understanding of the normal fetal central nervous system anatomy at varying gestational ages will aid in the imaging detection and interpretation of CNS pathology. Understanding how these appearances and diagnoses can change over time will aid in the discussion of prognosis with expectant parents, which is crucial in fetal CNS abnormalities. PMID:24078783

Senapati, Gunjan; Levine, Deborah

2013-01-01

127

Red-Backed Vole Brain Promotes Highly Efficient In Vitro Amplification of Abnormal Prion Protein from Macaque and Human Brains Infected with Variant Creutzfeldt-Jakob Disease Agent  

PubMed Central

Rapid antemortem tests to detect individuals with transmissible spongiform encephalopathies (TSE) would contribute to public health. We investigated a technique known as protein misfolding cyclic amplification (PMCA) to amplify abnormal prion protein (PrPTSE) from highly diluted variant Creutzfeldt-Jakob disease (vCJD)-infected human and macaque brain homogenates, seeking to improve the rapid detection of PrPTSE in tissues and blood. Macaque vCJD PrPTSE did not amplify using normal macaque brain homogenate as substrate (intraspecies PMCA). Next, we tested interspecies PMCA with normal brain homogenate of the southern red-backed vole (RBV), a close relative of the bank vole, seeded with macaque vCJD PrPTSE. The RBV has a natural polymorphism at residue 170 of the PrP-encoding gene (N/N, S/S, and S/N). We investigated the effect of this polymorphism on amplification of human and macaque vCJD PrPTSE. Meadow vole brain (170N/N PrP genotype) was also included in the panel of substrates tested. Both humans and macaques have the same 170S/S PrP genotype. Macaque PrPTSE was best amplified with RBV 170S/S brain, although 170N/N and 170S/N were also competent substrates, while meadow vole brain was a poor substrate. In contrast, human PrPTSE demonstrated a striking narrow selectivity for PMCA substrate and was successfully amplified only with RBV 170S/S brain. These observations suggest that macaque PrPTSE was more permissive than human PrPTSE in selecting the competent RBV substrate. RBV 170S/S brain was used to assess the sensitivity of PMCA with PrPTSE from brains of humans and macaques with vCJD. PrPTSE signals were reproducibly detected by Western blot in dilutions through 10-12 of vCJD-infected 10% brain homogenates. This is the first report showing PrPTSE from vCJD-infected human and macaque brains efficiently amplified with RBV brain as the substrate. Based on our estimates, PMCA showed a sensitivity that might be sufficient to detect PrPTSE in vCJD-infected human and macaque blood. PMID:24205298

Nemecek, Julie; Nag, Nabanita; Carlson, Christina M.; Schneider, Jay R.; Heisey, Dennis M.; Johnson, Christopher J.; Asher, David M.; Gregori, Luisa

2013-01-01

128

Functional, Morphological, and Metabolic Abnormalities of the Cerebral Microcirculation after Concussive Brain Injury in Cats  

Microsoft Academic Search

SUMMARY We induced experimental concussive brain injury by a fluid percussion device in anes- thetized cats equipped with a cranial window for the observation of the pial microcirculation of the parietal cortex. Brain injury resulted in transient but pronounced increases in arterial blood pressure and in sustained arteriolar vasodilation associated with reduced or absent responsiveness to the vasoconstrictor effect of

ENOCH P. WEI; W. DALTON DIETRICH; JOHN T. POVLISHOCK; RUDOLPH M. NAVARI; HERMES A. KONTOS

129

Structural brain abnormalities in the frontostriatal system and cerebellum in pedophilia  

Microsoft Academic Search

Even though previous neuropsychological studies and clinical case reports have suggested an association between pedophilia and frontocortical dysfunction, our knowledge about the neurobiological mechanisms underlying pedophilia is still fragmentary. Specifically, the brain morphology of such disorders has not yet been investigated using MR imaging techniques.Whole brain structural T1-weighted MR images from 18 pedophile patients (9 attracted to males, 9 attracted

Boris Schiffer; Thomas Peschel; Thomas Paul; Elke Gizewski; Michael Forsting; Norbert Leygraf; Manfred Schedlowski; Tillmann H. C. Krueger

2007-01-01

130

Decoupling neural networks from reality: dissociative experiences in torture victims are reflected in abnormal brain waves in left frontal cortex.  

PubMed

From a neuroscience perspective, little is known about the long-term effect of torture. Dissociative experiences and posttraumatic stress disorder are often the results of this experience. We examined psychological dissociation within a group of 23 torture victims and report its manifestations within neural networks in the human brain. In particular, we observed that dissociative experiences are associated with slow abnormal brain waves generated in left ventrolateral frontal cortex. Given that focal slow waves often result from depriving neural networks of major input, the present results may indicate decoupling of frontal affective processors from left cortical language areas. This interpretation is consistent with the fact that disturbed access to structured verbal memory concerning traumatic events is a core feature of the dissociative experience. PMID:17100779

Ray, William J; Odenwald, Michael; Neuner, Frank; Schauer, Maggie; Ruf, Martina; Wienbruch, Christian; Rockstroh, Brigitte; Elbert, Thomas

2006-10-01

131

Deletion in the N-terminal Half of Olfactomedin 1 Modifies Its Interaction with Synaptic Proteins and Causes Brain Dystrophy and Abnormal Behavior in Mice  

PubMed Central

Olfactomedin 1 (Olfm1) is a secreted glycoprotein that is preferentially expressed in neuronal tissues. Here we show that deletion of exons 4 and 5 from the Olfm1 gene, which encodes a 52 amino acid long region in the N-terminal part of the protein, increased neonatal death and reduced body weight of surviving homozygous mice. Magnetic resonance imaging analyses revealed reduced brain volume and attenuated size of white matter tracts such as the anterior commissure, corpus callosum, and optic nerve. Adult Olfm1 mutant mice demonstrated abnormal behavior in several tests including reduced marble digging, elevated plus maze test, nesting activity and latency on balance beam tests as compared with their wild-type littermates. The olfactory system was both structurally and functionally disturbed by the mutation in the Olfm1 gene as shown by functional magnetic resonance imaging analysis and a smell test. Deficiencies of the olfactory system may contribute to the neonatal death and loss of body weight of Olfm1 mutant. Shotgun proteomics revealed 59 candidate proteins that co-precipitated with wild-type or mutant Olfm1 proteins in postnatal day 1 brain. Olfm1-binding targets included GluR2, Cav2.1, Teneurin-4 and Kidins220. Modified interaction of Olfm1 with binding targets led to an increase in intracellular Ca2+ concentration and activation of ERK1/2, MEK1 and CaMKII in the hippocampus and olfactory bulb of Olfm1 mutant mice compared with their wild-type littermates. Excessive activation of the CaMKII and Ras-ERK pathways in the Olfm1 mutant olfactory bulb and hippocampus by elevated intracellular calcium may contribute to the abnormal behavior and olfactory activity of Olfm1 mutant mice. PMID:24095980

Nakaya, Naoki; Sultana, Afia; Munasinghe, Jeeva; Cheng, Aiwu; Mattson, Mark P.; Tomarev, Stanislav I.

2013-01-01

132

Brain Activity on Navigation in Virtual Environments.  

ERIC Educational Resources Information Center

Assessed the cognitive processing that takes place in virtual environments by measuring electrical brain activity using Fast Fourier Transform analysis. University students performed the same task in a real and a virtual environment, and eye movement measurements showed that all subjects were more attentive when navigating in the virtual world.…

Mikropoulos, Tassos A.

2001-01-01

133

Magnetic Resonance Microscopy Defines Ethanol-Induced Brain Abnormalities in Prenatal Mice: Effects of Acute Insult on Gestational Day 8  

PubMed Central

Background Magnetic resonance microscopy (MRM), magnetic resonance imaging (MRI) at microscopic levels, provides unprecedented opportunities to aid in defining the full spectrum of ethanol’s insult to the developing brain. This is the first in a series of reports that, collectively, will provide an MRM-based atlas of developmental stage-dependent structural brain abnormalities in a Fetal Alcohol Spectrum Disorders (FASD) mouse model. The ethanol exposure time and developmental stage examined for this report is gestational day (GD) 8 in mice, when the embryos are at early neurulation stages; stages present in humans early in the fourth week postfertilization. Methods For this study, pregnant C57Bl/6J mice were administered an ethanol dosage of 2.8 g/kg intraperitoneally at 8 days, 0 hour and again at 8 days, 4 hours postfertilization. On GD 17, fetuses that were selected for MRM analyses were immersion fixed in a Bouin’s/Prohance solution. Control fetuses from vehicle-treated dams were stage-matched to those that were ethanol-exposed. The fetal mice were scanned ex vivo at 7.0 T and 512 · 512 · 1024 image arrays were acquired using 3-D spin warp encoding. The resulting 29 lm (isotropic) resolution images were processed using ITK-SNAP, a 3-D segmentation/visualization tool. Linear and volume measurements were determined for selected brain, head, and body regions of each specimen. Comparisons were made between control and treated fetuses, with an emphasis on determining (dis)proportionate changes in specific brain regions. Results As compared with controls, the crown-rump lengths of stage-matched ethanol-exposed GD 17 fetuses were significantly reduced, as were brain and whole body volumes. Volume reductions were notable in every brain region examined, with the exception of the pituitary and septal region, and were accompanied by increased ventricular volumes. Disproportionate regional brain volume reductions were most marked on the right side and were significant for the olfactory bulb, hippocampus, and cerebellum; the latter being the most severely affected. Additionally, the septal region and the pituitary were disproportionately large. Linear measures were consistent with those of volume. Other dysmorphologic features noted in the MR scans were choanal stenosis and optic nerve coloboma. Conclusions This study demonstrates that exposure to ethanol occurring in mice at stages corresponding to the human fourth week postfertilization results in structural brain abnormalities that are readily identifiable at fetal stages of development. In addition to illustrating the utility of MR microscopy for analysis of an FASD mouse model, this work provides new information that confirms and extends human clinical observations. It also provides a framework for comparison of structural brain abnormalities resulting from ethanol exposure at other developmental stages and dosages. PMID:19302087

Parnell, Scott E.; O’Leary-Moore, Shonagh K.; Godin, Elizabeth A.; Dehart, Deborah B.; Johnson, Brice W.; Johnson, G. Allan; Styner, Martin A.; Sulik, Kathleen K.

2009-01-01

134

Abnormality of calmodulin activity in hypertension. Evidence of the presence of an activator.  

PubMed Central

An apparent increase of calmodulin (CaM) activity was previously observed in the heart and kidney but not in the liver of spontaneously-hypertensive rats (SHR) and mice compared with their corresponding normotensive controls. As this change was due to an elevated recovery of CaM in the organs of the hypertensive animals, the present study was designed to evaluate its activity in hypertension. A CaM activator, detected in heart and kidney supernatants from hypertensive animals, was found to be responsible for this enhanced recovery. Similar results were obtained with passaged, cultured aortic smooth muscle cells from SHR, indicating that the anomaly was not a mere consequence of elevated blood pressure but rather a genetic expression of cells of hypertensive origin. The activator was heat stable, nondialyzable, and recovered in the fraction precipitated with 30-50% ammonium sulfate. Preliminary extraction studies suggest that the activator is contained in a glycolipid fraction. The stimulation of phosphodiesterase by this activator was calcium and CaM dependent. The activator appears to affect the affinity of the phosphodiesterase for CaM rather than the maximal stimulation. The activator was also present at a low concentration in the heart and kidney of normotensive animals. These findings indicate that at least some of the calcium abnormalities implicated in the pathogenesis of hypertension could be the result of interactions between CaM, calcium, and this activator. PMID:2839548

Huang, S L; Wen, Y I; Kupranycz, D B; Pang, S C; Schlager, G; Hamet, P; Tremblay, J

1988-01-01

135

Three dimensional representation of brain electrical activity.  

PubMed

Brain topography mapping is a useful technique for the representation of electrical activity recorded on the scalp. It clarifies spatial and temporal relationships between different cortical areas. In this work we propose a system which includes several enhancements over those previously proposed, such as an optimised interpolation method and a three dimensional reconstruction of maps. This system is available in a personal computer environment. Results clearly show a superiority of the 3D representation over 2D maps obtained with different projections. The performance of this system in terms of speed and precision is comparable to that of dedicated image processing and image synthesis workstations proposed for brain mapping. PMID:7803200

Medina, V; Hassainia, F; Langevin, F; Gaillard, P

1994-01-01

136

Electromagnetic imaging of dynamic brain activity  

SciTech Connect

Neural activity in the brain produces weak dynamic electromagnetic fields that can be measured by an array of sensors. Using a spatio-temporal modeling framework, we have developed a new approach to localization of multiple neural sources. This approach is based on the MUSIC algorithm originally developed for estimating the direction of arrival of signals impinging on a sensor array. We present applications of this technique to magnetic field measurements of a phantom and of a human evoked somatosensory response. The results of the somatosensory localization are mapped onto the brain anatomy obtained from magnetic resonance images.

Mosher, J.; Leahy, R. (University of Southern California, Los Angeles, CA (United States). Dept. of Electrical Engineering); Lewis, P.; Lewine, J.; George, J. (Los Alamos National Lab., NM (United States)); Singh, M. (University of Southern California, Los Angeles, CA (United States). Dept. of Radiology)

1991-01-01

137

Electromagnetic imaging of dynamic brain activity  

SciTech Connect

Neural activity in the brain produces weak dynamic electromagnetic fields that can be measured by an array of sensors. Using a spatio-temporal modeling framework, we have developed a new approach to localization of multiple neural sources. This approach is based on the MUSIC algorithm originally developed for estimating the direction of arrival of signals impinging on a sensor array. We present applications of this technique to magnetic field measurements of a phantom and of a human evoked somatosensory response. The results of the somatosensory localization are mapped onto the brain anatomy obtained from magnetic resonance images.

Mosher, J.; Leahy, R. [University of Southern California, Los Angeles, CA (United States). Dept. of Electrical Engineering; Lewis, P.; Lewine, J.; George, J. [Los Alamos National Lab., NM (United States); Singh, M. [University of Southern California, Los Angeles, CA (United States). Dept. of Radiology

1991-12-31

138

The Relationship between Cognitive Functioning and Whole Brain Diffusion Tensor Imaging Abnormalities in Parkinson's Disease  

E-print Network

Abnormalities in Parkinson's Disease Michele York, Ph.D., Christof Karmonik, Ph.D., Robert Grossman, M Recently, a Parkinson's disease (PD)­related cognitive pattern (PDCP) was identified using positron.224762 0.230038 0.231515 LeftBA2 W W W W W W W W W W W W · Parkinson's disease · Healthy Control r =.95, p

Lichtarge, Olivier

139

Compact dynamical model of brain activity.  

PubMed

A compact physiologically based mean-field formulation of brain dynamics is proposed to model observed brain activity and electroencephalographic (EEG) signals. In contrast to existing formulations, which are more detailed and complicated, our model is described by a single second-order delay differential equation that encapsulates salient aspects of the physiology. The model captures essential features of activity mediated by fast corticocortical connections and delayed feedbacks via extracortical pathways and external stimuli. In the linear regime, these features can be simply expressed by three coefficients derived from the properties of these physiological pathways and explicit nonlinear approximations are also derived. This compact model successfully reproduces the main features of experimental EEG's and the predictions of previous models, including resonance peaks in EEG spectra and nonlinear dynamics. As an illustration, key features of the dynamics of epileptic seizures are shown to be reproduced by the model. Due to its compact form, the model will facilitate insight into nonlinear brain dynamics via standard nonlinear techniques and will guide analysis and investigation of more complex models. It is thus a useful tool for analyzing complex brain activity, especially when it exhibits low-dimensional dynamics. PMID:17500726

Kim, J W; Robinson, P A

2007-03-01

140

Compact dynamical model of brain activity  

NASA Astrophysics Data System (ADS)

A compact physiologically based mean-field formulation of brain dynamics is proposed to model observed brain activity and electroencephalographic (EEG) signals. In contrast to existing formulations, which are more detailed and complicated, our model is described by a single second-order delay differential equation that encapsulates salient aspects of the physiology. The model captures essential features of activity mediated by fast corticocortical connections and delayed feedbacks via extracortical pathways and external stimuli. In the linear regime, these features can be simply expressed by three coefficients derived from the properties of these physiological pathways and explicit nonlinear approximations are also derived. This compact model successfully reproduces the main features of experimental EEG’s and the predictions of previous models, including resonance peaks in EEG spectra and nonlinear dynamics. As an illustration, key features of the dynamics of epileptic seizures are shown to be reproduced by the model. Due to its compact form, the model will facilitate insight into nonlinear brain dynamics via standard nonlinear techniques and will guide analysis and investigation of more complex models. It is thus a useful tool for analyzing complex brain activity, especially when it exhibits low-dimensional dynamics.

Kim, J. W.; Robinson, P. A.

2007-03-01

141

Temporal organization of ongoing brain activity  

NASA Astrophysics Data System (ADS)

Ongoing brain activity results from the mutual interaction of hundred billions non-linear units and represents a significant part of the overall brain activity. Although its complex dynamics has been widely investigated, a large number of fundamental questions are still open, many of them concerning its temporal structure. Why does a certain population of neurons fires synchronously? Are these synchronized bursts following each other randomly or are they correlated according to some organizing principle? Far from addressing the fundamental problem of its functions, in the present article we focus on the problem of temporal correlations of ongoing cortical activity. We first overview the major features of its temporal structure and review recent experimental results, with particular emphasis on alternative approaches inspired in the theory of stochastic processes; then we introduce a neuronal network model inspired in self organized criticality and compare numerical results with experimental findings.

Lombardi, F.; de Arcangelis, L.

2014-10-01

142

NonStationary Shape Activities: Tracking & Abnormality Detection  

E-print Network

motion. Valid model for: Distant PTZ camera rotated to align with line of sight Random jitter of UAV · Use estimated global motion to control a PTZ camera or a UAV to "follow" a "moving" activity 9 #12;A · Sensor independent approach ­ Observations may be obtained using any sensor, e.g. audio, infra-red, radar

Vaswani, Namrata

143

Effect of contrast leakage on the detection of abnormal brain tumor vasculature in high-grade glioma  

PubMed Central

Abnormal brain tumor vasculature has recently been highlighted by a dynamic susceptibility contrast (DSC) MRI processing technique. The technique uses independent component analysis (ICA) to separate arterial and venous perfusion. The overlap of the two, i.e. arterio-venous overlap or AVOL, preferentially occurs in brain tumors and predicts response to anti-angiogenic therapy. The effects of contrast agent leakage on the AVOL biomarker have yet to be established. DSC was acquired during two separate contrast boluses in ten patients undergoing clinical imaging for brain tumor diagnosis. Three components were modeled with ICA, which included the arterial and venous components. The percentage of each component as well as a third component were determined within contrast enhancing tumor and compared. AVOL within enhancing tumor was also compared between doses. The percentage of enhancing tumor classified as not arterial or venous and instead into a third component with contrast agent leakage apparent in the time-series was significantly greater for the first contrast dose compared to the second. The amount of AVOL detected within enhancing tumor was also significantly greater with the second dose compared to the first. Contrast leakage results in large signal variance classified as a separate component by the ICA algorithm. The use of a second dose mitigates the effect and allows measurement of AVOL within enhancement. PMID:24293201

Paulson, Eric S.; Schmainda, Kathleen M.

2014-01-01

144

Effects of familiar voices on brain activity.  

PubMed

This study aimed to examine the extent to which a familiar voice influences brain activity. Participants were nine healthy female volunteers aged 21-34 years old (with a mean age of 25.78 ± 4.04 years). Brain activity was recorded during periods of silence, familiar and unfamiliar voices. Electroencephalographic data were collected and analyzed using a frequency rate set at 5 min. To account for emotional influences imbedded into the contents of the voice stimuli, both the voice of a familiar family member and the voice of a stranger were used to record a well-known Japanese fairy tale, 'Momotaro'. Results revealed that listening to familiar voices increased the rate of the ? band (13-30 Hz) in all four brain areas (F3, F4, C3 and C4). In particular, increased activity was observed at F4 and C4. Findings revealed that in study, participants' familiar voices activated cerebral functioning more than unfamiliar voices. PMID:22776531

Tanaka, Yuji L; Kudo, Yumi

2012-07-01

145

Running in the family? : structural brain abnormalities in first-degree relatives of patients with schizophrenia  

Microsoft Academic Search

The studies conducted in this thesis explored brain structures in first-degree relatives of patients with schizophrenia. The meta-analysis that Boos and colleagues performed showed that relatives of patients with schizophrenia had smaller hippocampal volumes, smaller gray matter volumes and larger third ventricle volumes compared to controls. These volumetric differences are similar to the areas that are affected in patients with

H. B. M. Boos

2011-01-01

146

Air Pollution, Cognitive Deficits and Brain Abnormalities: A Pilot Study with Children and Dogs  

ERIC Educational Resources Information Center

Exposure to air pollution is associated with neuroinflammation in healthy children and dogs in Mexico City. Comparative studies were carried out in healthy children and young dogs similarly exposed to ambient pollution in Mexico City. Children from Mexico City (n:55) and a low polluted city (n:18) underwent psychometric testing and brain magnetic…

Calderon-Garciduenas, Lilian; Mora-Tiscareno, Antonieta; Ontiveros, Esperanza; Gomez-Garza, Gilberto; Barragan-Mejia, Gerardo; Broadway, James; Chapman, Susan; Valencia-Salazar, Gildardo; Jewells, Valerie; Maronpot, Robert R.; Henriquez-Roldan, Carlos; Perez-Guille, Beatriz; Torres-Jardon, Ricardo; Herrit, Lou; Brooks, Diane; Osnaya-Brizuela, Norma; Monroy, Maria E.; Gonzalez-Maciel, Angelica; Reynoso-Robles, Rafael; Villarreal-Calderon, Rafael; Solt, Anna C.; Engle, Randall W.

2008-01-01

147

Air pollution, cognitive deficits and brain abnormalities: A pilot study with children and dogs  

Microsoft Academic Search

Exposure to air pollution is associated with neuroinflammation in healthy children and dogs in Mexico City. Comparative studies were carried out in healthy children and young dogs similarly exposed to ambient pollution in Mexico City. Children from Mexico City (n: 55) and a low polluted city (n:18) underwent psychometric testing and brain magnetic resonance imaging MRI. Seven healthy young dogs

Lilian Calderón-Garcidueñas; Antonieta Mora-Tiscareño; Esperanza Ontiveros; Gilberto Gómez-Garza; Gerardo Barragán-Mejía; James Broadway; Susan Chapman; Gildardo Valencia-Salazar; Valerie Jewells; Robert R. Maronpot; Carlos Henríquez-Roldán; Beatriz Pérez-Guillé; Ricardo Torres-Jardón; Lou Herrit; Diane Brooks; Norma Osnaya-Brizuela; Maria E. Monroy; Angelica González-Maciel; Rafael Reynoso-Robles; Rafael Villarreal-Calderon; Anna C Solt; Randall W. Engle

2008-01-01

148

Brief Report: Abnormal Association between the Thalamus and Brain Size in Asperger's Disorder  

ERIC Educational Resources Information Center

The objective of this study was to examine the relationship between thalamic volume and brain size in individuals with Asperger's disorder (ASP). Volumetric measurements of the thalamus were performed on MRI scans obtained from 12 individuals with ASP (age range: 10-35 years) and 12 healthy controls (age range: 9-33 years). A positive correlation…

Hardan, Antonio Y.; Girgis, Ragy R.; Adams, Jason; Gilbert, Andrew R.; Melhem, Nadine M.; Keshavan, Matcheri S.; Minshew, Nancy J.

2008-01-01

149

Physical activity, air pollution and the brain.  

PubMed

This review introduces an emerging research field that is focused on studying the effect of exposure to air pollution during exercise on cognition, with specific attention to the impact on concentrations of brain-derived neurotrophic factor (BDNF) and inflammatory markers. It has been repeatedly demonstrated that regular physical activity enhances cognition, and evidence suggests that BDNF, a neurotrophin, plays a key role in the mechanism. Today, however, air pollution is an environmental problem worldwide and the high traffic density, especially in urban environments and cities, is a major cause of this problem. During exercise, the intake of air pollution increases considerably due to an increased ventilation rate and particle deposition fraction. Recently, air pollution exposure has been linked to adverse effects on the brain such as cognitive decline and neuropathology. Inflammation and oxidative stress seem to play an important role in inducing these health effects. We believe that there is a need to investigate whether the well-known benefits of regular physical activity on the brain also apply when physical activity is performed in polluted air. We also report our findings about exercising in an environment with ambient levels of air pollutants. Based on the latter results, we hypothesize that traffic-related air pollution exposure during exercise may inhibit the positive effect of exercise on cognition. PMID:25119155

Bos, Inge; De Boever, Patrick; Int Panis, Luc; Meeusen, Romain

2014-11-01

150

Bilateral brain abnormalities associated with dominantly inherited verbal and orofacial dyspraxia  

Microsoft Academic Search

The KE family is a large three-generational pedigree in which half of the members suffer from a verbal and orofacial dyspraxia in association with a point mutation in the FOXP2 gene. This report extends previous voxel-based morphometric analyses of magnetic resonance imaging (MRI) scans (Watkins et al. (2002) Brain 125:465- 478) using a bilateral conjunction analysis. This searches specifically for

Emma Belton; Claire H. Salmond; Kate E. Watkins; Faraneh Vargha-Khadem; David G. Gadian

2003-01-01

151

Abnormal Brain Default-Mode Network Functional Connectivity in Drug Addicts  

Microsoft Academic Search

BackgroundThe default mode network (DMN) is a set of brain regions that exhibit synchronized low frequency oscillations at resting-state, and is believed to be relevant to attention and self-monitoring. As the anterior cingulate cortex and hippocampus are impaired in drug addiction and meanwhile are parts of the DMN, the present study examined addiction-related alteration of functional connectivity of the DMN.MethodologyResting-state

Ning Ma; Ying Liu; Xian-Ming Fu; Nan Li; Chang-Xin Wang; Hao Zhang; Ruo-Bing Qian; Hu-Sheng Xu; Xiaoping Hu; Da-Ren Zhang; Ben Harrison

2011-01-01

152

Evidence of persistent blood-brain barrier abnormalities in chronic-progressive multiple sclerosis  

Microsoft Academic Search

Brain capillaries were analyzed morphometrically for alterations in organelle distribution and density in biopsy samples of central nervous system tissue from seven patients diagnosed as having chronic progressive multiple sclerosis. Data were expressed as percentage of endothelial cytoplasm occupied by the respective organelles. The density of pinocytotic vesicles in endothelium ranged from 0.53% within normal-appearing parenchyma to 1.2% in gliotic

Luz Claudio; Cedric S. Raine; Celia F. Brosnan

1995-01-01

153

Statistical Parametric Mapping of Brain SPECT Perfusion Abnormalities in Patients with Alzheimer’s Disease  

Microsoft Academic Search

Brain perfusion in 20 patients with mild Alzheimer’s disease (AD), 20 patients with moderate AD and 20 control subjects (matched for age, gender and education) were assessed by single photon emission computed tomography (SPECT) using technetium-99m hexamethylpropylene amine oxime (99mTc-HMPAO). SPECT images were transformed to a standard size and shape for group comparisons by the voxel-based t test of the

Yi-Chung Lee; Ren-Shyan Liu; Yi-Chu Liao; Chen-Ming Sun; Po-Shan Wang; Pei-Ning Wang; Hsiu-Chih Liu

2003-01-01

154

Neuroretinitis with abnormal brain imaging in Ask-Upmark kidney: A novel case report  

PubMed Central

We report a 13-year-old female patient having vertigo and visual blurring since 2 weeks with blood pressure being 180/106 mmHg. Fundus examination showed optic disc edema with macular star. After ruling out infective causes, idiopathic neuroretinitis was diagnosed. Her brain magnetic resonance imaging (MRI) scan revealed three periventricular morphologically multiple sclerosis (MS)-like white matter lesions. Renal ultrasound and renal arteriogram showed a shrunken left kidney, small non-stenotic left renal artery and reduced vessels in upper pole of left kidney, consistent with Ask-Upmark kidney (AUK). Her symptoms improved with antihypertensive drugs. Follow-up MRI at 1 year revealed no interval change, while fundus had normalized. Neuroretinitis typically has normal brain MRI and rules out MS. However, our patient having AUK-induced hypertension had neuroretinitis and MS-like brain lesions and did not fulfill diagnostic criteria for MS. Thus we postulate that MS-like lesions can be part of neuroretinitis, especially in hypertensive patients. PMID:25250080

Kasundra, Gaurav M.; Sood, Isha; Prakash, Sanjay; Mehta, Dhruv P.

2014-01-01

155

Surface reconstructions of foetal brain abnormalities using ultrafast steady state 3D acquisitions.  

PubMed

MRI of the foetal brain in utero is performed in routine clinical practice using sequences that produce two-dimensional (2D) images. Recent developments in image post-processing have allowed the construction of three-dimensional (3D) volume data sets from 2D images acquired in different anatomical planes, but these have limitations due to the unpredictable nature of foetal movement. These limitations have been overcome by development of several different advanced computer techniques, which require specialist knowledge, software, and processing methods, which are rarely available in routine clinical settings. Our aim was to develop a technique that can be used in routine clinical situations without the need for custom-developed or expensive software by utilizing MRI sequences that can produce a 3D data set in "ultrafast" timescales. The 3D dataset, combined with versatile image post-processing and visualization techniques, has resulted in the production of high-resolution images of foetal brain surfaces in utero. The aim of this paper is to demonstrate our methods and early results by way of a pictorial review illustrating a range of developmental brain disease in utero. PMID:25062925

Jarvis, D A; Armitage, P; Dean, A; Griffiths, P D

2014-10-01

156

A gel-based proteomic method reveals several protein pathway abnormalities in fetal Down syndrome brain.  

PubMed

A large series of protein pathway components have been shown to be dysregulated in Down syndrome (DS) brain. No information about pathomechanisms linked to the trisomic state can be obtained from adult DS brain, however, as neurodegeneration occurs from the fourth decade. The aim of the study was to search for protein dysregulation in fetal DS brain before neurodegenerative changes are observed. Proteins were extracted from fetal DS and control frontal cortex, run on 2-DE, followed by quantification of protein spots with subsequent nano-ESI-LC-MS/MS analysis using an ion trap. Aberrant expression of proteins tropomodulin-2, tubulin alpha 1A chain, and alpha-internexin may indicate disturbed synaptic plasticity; fatty acid binding protein 7 suggests impaired maintenance of neuroepithelial cells; and creatine kinase B may reflect defective energy metabolism. RNA binding protein 4B derangement may represent impaired splicing, altered retrotransposon gag domain-containing protein 1 levels may be pointing to altered retrotransposition, and level changes of the potassium-chloride transporter solute carrier family 12 member 7 may lead to impaired ion fluxes with electrophysiological consequences. Taken together, aberrant protein levels from several pathways in fetal DS are challenging as well as fertilizing the area of research and providing the basis for additional neurochemical and functional studies. PMID:21262400

Sun, Yanwei; Dierssen, Mara; Toran, Nuria; Pollak, Daniela D; Chen, Wei-Qiang; Lubec, Gert

2011-04-01

157

Whole-brain functional connectivity during emotional word classification in medication-free Major Depressive Disorder: Abnormal salience circuitry and relations to positive emotionality.  

PubMed

Major Depressive Disorder (MDD) has been associated with biased processing and abnormal regulation of negative and positive information, which may result from compromised coordinated activity of prefrontal and subcortical brain regions involved in evaluating emotional information. We tested whether patients with MDD show distributed changes in functional connectivity with a set of independently derived brain networks that have shown high correspondence with different task demands, including stimulus salience and emotional processing. We further explored if connectivity during emotional word processing related to the tendency to engage in positive or negative emotional states. In this study, 25 medication-free MDD patients without current or past comorbidity and matched controls (n = 25) performed an emotional word-evaluation task during functional MRI. Using a dual regression approach, individual spatial connectivity maps representing each subject's connectivity with each standard network were used to evaluate between-group differences and effects of positive and negative emotionality (extraversion and neuroticism, respectively, as measured with the NEO-FFI). Results showed decreased functional connectivity of the medial prefrontal cortex, ventrolateral prefrontal cortex, and ventral striatum with the fronto-opercular salience network in MDD patients compared to controls. In patients, abnormal connectivity was related to extraversion, but not neuroticism. These results confirm the hypothesis of a relative (para)limbic-cortical decoupling that may explain dysregulated affect in MDD. As connectivity of these regions with the salience network was related to extraversion, but not to general depression severity or negative emotionality, dysfunction of this network may be responsible for the failure to sustain engagement in rewarding behavior. PMID:24179829

van Tol, Marie-José; Veer, Ilya M; van der Wee, Nic J A; Aleman, André; van Buchem, Mark A; Rombouts, Serge A R B; Zitman, Frans G; Veltman, Dick J; Johnstone, Tom

2013-01-01

158

Apathy is associated with white matter abnormalities in anterior, medial brain regions in persons with HIV infection  

PubMed Central

Apathy is a relatively common psychiatric syndrome in HIV infection, but little is known about its neural correlates. In the present study, we examined the associations between apathy and diffusion tensor imaging (DTI) indices in key frontal white matter regions in the thalamocorticostriatal circuit that has been implicated in the expression of apathy. Nineteen participants with HIV infection and 19 demographically comparable seronegative comparison subjects completed the Apathy subscale of the Frontal Systems Behavioral Scale as a part of a comprehensive neuropsychiatric research evaluation. When compared to the seronegative participants, the HIV+ group had significantly more frontal white matter abnormalities. Within HIV+ persons, and as predicted, higher ratings of apathy were associated with greater white matter alterations in the anterior corona radiata, genu, and orbital medial prefrontal cortex. The associations between white matter alterations and apathy were independent of depression and were stronger among participants with lower current CD4 counts. All told, these findings indicate that apathy is independently associated with white matter abnormalities in anterior, medial brain regions in persons infected with HIV, particularly in the setting of lower current immune functioning, which may have implications for antiretroviral therapy. PMID:25275424

Kamat, Rujvi; Brown, Gregory G.; Bolden, Khalima; Fennema-Notestine, Christine; Archibald, Sarah; Marcotte, Thomas D.; Letendre, Scott L.; Ellis, Ronald J.; Woods, Steven Paul; Grant, Igor; Heaton, Robert K.

2015-01-01

159

Predicting risky choices from brain activity patterns.  

PubMed

Previous research has implicated a large network of brain regions in the processing of risk during decision making. However, it has not yet been determined if activity in these regions is predictive of choices on future risky decisions. Here, we examined functional MRI data from a large sample of healthy subjects performing a naturalistic risk-taking task and used a classification analysis approach to predict whether individuals would choose risky or safe options on upcoming trials. We were able to predict choice category successfully in 71.8% of cases. Searchlight analysis revealed a network of brain regions where activity patterns were reliably predictive of subsequent risk-taking behavior, including a number of regions known to play a role in control processes. Searchlights with significant predictive accuracy were primarily located in regions more active when preparing to avoid a risk than when preparing to engage in one, suggesting that risk taking may be due, in part, to a failure of the control systems necessary to initiate a safe choice. Additional analyses revealed that subject choice can be successfully predicted with minimal decrements in accuracy using highly condensed data, suggesting that information relevant for risky choice behavior is encoded in coarse global patterns of activation as well as within highly local activation within searchlights. PMID:24550270

Helfinstein, Sarah M; Schonberg, Tom; Congdon, Eliza; Karlsgodt, Katherine H; Mumford, Jeanette A; Sabb, Fred W; Cannon, Tyrone D; London, Edythe D; Bilder, Robert M; Poldrack, Russell A

2014-02-18

160

Predicting risky choices from brain activity patterns  

PubMed Central

Previous research has implicated a large network of brain regions in the processing of risk during decision making. However, it has not yet been determined if activity in these regions is predictive of choices on future risky decisions. Here, we examined functional MRI data from a large sample of healthy subjects performing a naturalistic risk-taking task and used a classification analysis approach to predict whether individuals would choose risky or safe options on upcoming trials. We were able to predict choice category successfully in 71.8% of cases. Searchlight analysis revealed a network of brain regions where activity patterns were reliably predictive of subsequent risk-taking behavior, including a number of regions known to play a role in control processes. Searchlights with significant predictive accuracy were primarily located in regions more active when preparing to avoid a risk than when preparing to engage in one, suggesting that risk taking may be due, in part, to a failure of the control systems necessary to initiate a safe choice. Additional analyses revealed that subject choice can be successfully predicted with minimal decrements in accuracy using highly condensed data, suggesting that information relevant for risky choice behavior is encoded in coarse global patterns of activation as well as within highly local activation within searchlights. PMID:24550270

Helfinstein, Sarah M.; Schonberg, Tom; Congdon, Eliza; Karlsgodt, Katherine H.; Mumford, Jeanette A.; Sabb, Fred W.; Cannon, Tyrone D.; London, Edythe D.; Bilder, Robert M.; Poldrack, Russell A.

2014-01-01

161

Structural connectivity abnormality in children with acute mild traumatic brain injury using graph theoretical analysis.  

PubMed

The traumatic biomechanical forces associated with mild traumatic brain injury (mTBI) typically impart diffuse, as opposed to focal, brain injury potentially disrupting the structural connectivity between neural networks. Graph theoretical analysis using diffusion tensor imaging was used to assess injury-related differences in structural connectivity between 23 children (age 11-16 years) with mTBI and 20 age-matched children with isolated orthopedic injuries (OI) scanned within 96 h postinjury. The distribution of hub regions and the associations between alterations in regional network measures and symptom burden, as assessed by the postconcussion symptom scale score (PCSS), were also examined. In comparison to the OI group, the mTBI group was found to have significantly higher small-worldness (P?Brain Mapp, 2014. © 2014 Wiley Periodicals, Inc. PMID:25363671

Yuan, Weihong; Wade, Shari L; Babcock, Lynn

2014-11-01

162

Segmentation of the brain from 3D MRI using a hierarchical active surface template  

NASA Astrophysics Data System (ADS)

The accurate segmentation of the brain from three-dimensional medical imagery is important as the basis for visualization, morphometry, surgical planning and intraoperative navigation. The complex and variable nature of brain anatomy makes recognition of the brain boundaries a difficult problem and frustrates segmentation schemes based solely on local image features. We have developed a deformable surface model of the brain as a mechanism for utilizing a priori anatomical knowledge in the segmentation process. The active surface template uses an energy minimization scheme to find a globally consistent surface configuration given a set of potentially ambiguous image features. Solution of the entire 3D problem at once produces superior results to those achieved using a slice by slice approach. We have achieved good results with MR image volumes of both normal and abnormal subjects. Evaluation of the segmentation results has been performed using cadaver studies.

Snell, John W.; Merickel, Michael B.; Ortega, James M.; Goble, John C.; Brookeman, James R.; Kassell, Neal F.

1994-05-01

163

Investigating brain community structure abnormalities in bipolar disorder using PLACE (Path Length Associated Community Estimation)  

PubMed Central

In this paper, we present PLACE, a comprehensive framework for studying node-level community structure. Instead of the well-known Q modularity metric, PLACE utilizes a novel metric, ?PL, which measures the difference between inter-community versus intra-community path lengths. We compared community structures in human healthy brain networks generated using these two metrics, and argued that ?PL may have theoretical advantages. PLACE consists of the following: 1) extracting community structure using top-down hierarchical binary trees, where a branch at each bifurcation denotes a collection of nodes that form a community at that level, 2) constructing and assessing mean group community structure, and 3) detecting node-level changes in community between groups. We applied PLACE and investigated the structural brain networks obtained from a sample of 25 euthymic bipolar I subjects versus 25 gender and age matched healthy controls. Results showed community structural differences in posterior default mode network (DMN) regions, with the bipolar group exhibiting left-right decoupling. PMID:23798337

GadElkarim, Johnson J.; Ajilore, Olusola; Schonfeld, Dan; Zhan, Liang; Thomspon, Paul M.; Feusner, Jamie D.; Kumar, Anand; Altshuler, Lori L.; Leow, Alex D.

2014-01-01

164

Left Atrial Volumes and Reservoir Function Are Associated With Subclinical Cerebrovascular Disease: The Cardiovascular Abnormalities and Brain Lesions (CABL) Study  

PubMed Central

Objectives To assess the relationship of left atrial (LA) phasic volumes and LA reservoir function with subclinical cerebrovascular disease in a stroke-free community-based cohort. Background An increase in LA size is associated with cardiovascular events including stroke. However, it is not known whether LA phasic volumes and reservoir function are associated with subclinical cerebrovascular disease. Methods LA minimum (LAVmin) and maximum (LAVmax) volumes, and LA reservoir function, measured as total emptying volume (LAEV) and total emptying fraction (LAEF), were assessed by real-time three-dimensional echocardiography in 455 stroke-free participants from the community-based Cardiovascular Abnormalities and Brain Lesions (CABL) study. Subclinical cerebrovascular disease was assessed as silent brain infarcts (SBI) and white matter hyperintensity volume (WMHV) by brain magnetic resonance imaging (MRI). Results SBI prevalence was 15.4%; mean WMHV was 0.66±0.92%. Participants with SBI showed greater LAVmin (17.1±9.3 vs. 12.5±5.6 ml/m2, p<0.01) and LAVmax (26.6±8.8 vs. 23.3±7.0 ml/m2, p<0.01) compared to those without SBI. LAEV (9.5±3.4 vs. 10.8±3.9 ml/m2, p<0.01) and LAEF (38.7±14.7% vs. 47.0±11.9%, p<0.01) were also reduced in participants with SBI. In univariate analyses, greater LA volumes and smaller reservoir function were significantly associated with greater WMHV. In multivariate analyses, LAVmin remained significantly associated with SBI [adjusted odds ratio (OR) per SD increase: 1.37, 95% confidence intervals (CI) 1.04–1.80, p<0.05] and with WMHV (?=0.12, p<0.01), whereas LAVmax was not independently associated with either. Smaller LAEF was independently associated with SBI (adjusted OR=0.67, 95% CI 0.50–0.90, p<0.01) and WMHV (?=?0.09, p<0.05). Conclusions Greater LA volumes and reduced LA reservoir function are associated with subclinical cerebrovascular disease detected by brain MRI in subjects without history of stroke. LAVmin and LAEF, in particular, are more strongly associated with SBI and WMHV than the more commonly measured LAVmax, and their relationship with subclinical brain lesions is independent of other cardiovascular risk factors. PMID:23473112

Russo, Cesare; Jin, Zhezhen; Liu, Rui; Iwata, Shinichi; Tugcu, Aylin; Yoshita, Mitsuhiro; Homma, Shunichi; Elkind, Mitchell S.V.; Rundek, Tatjana; DeCarli, Charles; Wright, Clinton B.; Sacco, Ralph L.; Di Tullio, Marco R.

2013-01-01

165

“Pooled analysis of brain activity in Irritable Bowel Syndrome and controls during rectal balloon distension”  

PubMed Central

Background Brain-imaging literature of Irritable Bowel Syndrome (IBS) suggests an abnormal brain-gut communication. We analyzed the literature to evaluate and compare the aspects of brain activity in individuals with IBS and control subjects experiencing controlled rectal stimulation. Methods PubMed was searched until September 2010. Data from 16 articles reporting brain activity during rectal balloon distensions in IBS compared to control groups was analyzed. Prevalence rates and pairwise activations were assessed using binomial distributions for 11 selected regions of interest. The data was aggregated to adjust for center effect. Key Results There was considerable variability in the literature regarding regions and their activity patterns in controls and individuals with IBS. There was no significant difference found in the thalamus, ACC, PCC, and PFC, however results show limited evidence of consensus for the Anterior Insula (AI) (p = 0.22). Pairwise activity results suggest that pairs involving the AI tend to have more consistent activity together than pairs which do not involve the AI (Posterior Insula and AI, p = 0.08; Posterior Cingulate Cortex and AI, p = 0.16), however no pairwise evaluation reached significance. Conclusions & Inferences Our pooled analysis demonstrates that the literature reports are quite heterogeneous but there is some evidence that there may be patterns of higher activity more common in individuals with IBS than in controls. A consensus, though, regarding study designs, analysis approach and reporting could create a clearer understanding of brain involvement in IBS pathophysiology. PMID:21118328

Sheehan, James; Gaman, Alexander; Vangel, Mark; Kuo, Braden

2010-01-01

166

Measuring Abnormal Brains: Building Normative Rules in Neuroimaging Using One-Class Support Vector Machines  

PubMed Central

Pattern recognition methods have demonstrated to be suitable analyses tools to handle the high dimensionality of neuroimaging data. However, most studies combining neuroimaging with pattern recognition methods focus on two-class classification problems, usually aiming to discriminate patients under a specific condition (e.g., Alzheimer’s disease) from healthy controls. In this perspective paper we highlight the potential of the one-class support vector machines (OC-SVM) as an unsupervised or exploratory approach that can be used to create normative rules in a multivariate sense. In contrast with the standard SVM that finds an optimal boundary separating two classes (discriminating boundary), the OC-SVM finds the boundary enclosing a specific class (characteristic boundary). If the OC-SVM is trained with patterns of healthy control subjects, the distance to the boundary can be interpreted as an abnormality score. This score might allow quantification of symptom severity or provide insights about subgroups of patients. We provide an intuitive description of basic concepts in one-class classification, the foundations of OC-SVM, current applications, and discuss how this tool can bring new insights to neuroimaging studies. PMID:23248579

Sato, João Ricardo; Rondina, Jane Maryam; Mourão-Miranda, Janaina

2012-01-01

167

Automated detection of brain abnormalities in neonatal hypoxia ischemic injury from MR images.  

PubMed

We compared the efficacy of three automated brain injury detection methods, namely symmetry-integrated region growing (SIRG), hierarchical region splitting (HRS) and modified watershed segmentation (MWS) in human and animal magnetic resonance imaging (MRI) datasets for the detection of hypoxic ischemic injuries (HIIs). Diffusion weighted imaging (DWI, 1.5T) data from neonatal arterial ischemic stroke (AIS) patients, as well as T2-weighted imaging (T2WI, 11.7T, 4.7T) at seven different time-points (1, 4, 7, 10, 17, 24 and 31 days post HII) in rat-pup model of hypoxic ischemic injury were used to assess the temporal efficacy of our computational approaches. Sensitivity, specificity, and similarity were used as performance metrics based on manual ('gold standard') injury detection to quantify comparisons. When compared to the manual gold standard, automated injury location results from SIRG performed the best in 62% of the data, while 29% for HRS and 9% for MWS. Injury severity detection revealed that SIRG performed the best in 67% cases while 33% for HRS. Prior information is required by HRS and MWS, but not by SIRG. However, SIRG is sensitive to parameter-tuning, while HRS and MWS are not. Among these methods, SIRG performs the best in detecting lesion volumes; HRS is the most robust, while MWS lags behind in both respects. PMID:25000294

Ghosh, Nirmalya; Sun, Yu; Bhanu, Bir; Ashwal, Stephen; Obenaus, Andre

2014-10-01

168

Feature extraction and dimensions reduction using R transform and Principal Component Analysis for abnormal human activity recognition  

Microsoft Academic Search

In this paper the recognition of abnormal human activities: forward fall, backward fall, chest pain, fainting, vomiting, and headache is studied. The proposed system model presents a novel combination of R transform and Principal Component Analysis (PCA) for abnormal activity recognition. The idea is to take advantage of both local and global feature extractions by R transform and PCA methods

Zafar Ali Khan; Won Sohn

2010-01-01

169

Late Prenatal Immune Activation in Mice Leads to Behavioral and Neurochemical Abnormalities Relevant to the Negative Symptoms of Schizophrenia  

Microsoft Academic Search

Based on the human epidemiological association between prenatal infection and higher risk of schizophrenia, a number of animal models have been established to explore the long-term brain and behavioral consequences of prenatal immune challenge. Accumulating evidence suggests that the vulnerability to specific forms of schizophrenia-related abnormalities is critically influenced by the precise timing of the prenatal immunological insult. In the

Byron KY Bitanihirwe; Daria Peleg-Raibstein; Forouhar Mouttet; Joram Feldon; Urs Meyer

2010-01-01

170

Are Auditory Hallucinations Related to the Brain's Resting State Activity? A 'Neurophenomenal Resting State Hypothesis'.  

PubMed

While several hypotheses about the neural mechanisms underlying auditory verbal hallucinations (AVH) have been suggested, the exact role of the recently highlighted intrinsic resting state activity of the brain remains unclear. Based on recent findings, we therefore developed what we call the 'resting state hypotheses' of AVH. Our hypothesis suggest that AVH may be traced back to abnormally elevated resting state activity in auditory cortex itself, abnormal modulation of the auditory cortex by anterior cortical midline regions as part of the default-mode network, and neural confusion between auditory cortical resting state changes and stimulus-induced activity. We discuss evidence in favour of our 'resting state hypothesis' and show its correspondence with phenomenal, i.e., subjective-experiential features as explored in phenomenological accounts. Therefore I speak of a 'neurophenomenal resting state hypothesis' of auditory hallucinations in schizophrenia. PMID:25598821

Northoff, Georg

2014-12-01

171

Are Auditory Hallucinations Related to the Brain's Resting State Activity? A 'Neurophenomenal Resting State Hypothesis'  

PubMed Central

While several hypotheses about the neural mechanisms underlying auditory verbal hallucinations (AVH) have been suggested, the exact role of the recently highlighted intrinsic resting state activity of the brain remains unclear. Based on recent findings, we therefore developed what we call the 'resting state hypotheses' of AVH. Our hypothesis suggest that AVH may be traced back to abnormally elevated resting state activity in auditory cortex itself, abnormal modulation of the auditory cortex by anterior cortical midline regions as part of the default-mode network, and neural confusion between auditory cortical resting state changes and stimulus-induced activity. We discuss evidence in favour of our 'resting state hypothesis' and show its correspondence with phenomenal, i.e., subjective-experiential features as explored in phenomenological accounts. Therefore I speak of a 'neurophenomenal resting state hypothesis' of auditory hallucinations in schizophrenia. PMID:25598821

2014-01-01

172

MnSOD activity protects mitochondrial morphology of quiescent fibroblasts from age associated abnormalities  

PubMed Central

Previously, we have shown manganese superoxide dismutase (MnSOD) activity protects quiescent human normal skin fibroblasts (NHFs) from age associated loss in proliferative capacity. The loss in proliferative capacity of aged vs. young quiescent cells is often characterized as the chronological life span, which is clearly distinct from replicative senescence. We investigate the hypothesis that MnSOD activity protects the mitochondrial morphology from age associated damage and preserves the chronological life span of quiescent fibroblasts. Aged quiescent NHFs exhibited abnormalities in mitochondrial morphology including abnormal cristae formation and increased number of vacuoles. These results correlate with the levels of cellular reactive oxygen species (ROS) and mitochondrial morphology in MnSOD homozygous and heterozygous knockout mouse embryonic fibroblasts. The abnormalities in mitochondrial morphology in aged quiescent NHFs cultured in presence of 21% oxygen concentration were more severe than NHFs cultured in 4% oxygen environment. The alteration in mitochondrial morphology was associated with a significant increase in cell population doubling: 54 h in 21% compared to 44 h in 4% oxygen environment. Overexpression of MnSOD decreased ROS levels, and preserved mitochondrial morphology in aged quiescent NHFs. These results demonstrate that MnSOD activity protects mitochondrial morphology and preserves the proliferative capacities of quiescent NHFs from age associated loss. PMID:20206302

Sarsour, Ehab H.; Goswami, Monali; Kalen, Amanda L.; Goswami, Prabhat C.

2010-01-01

173

Meclozine facilitates proliferation and differentiation of chondrocytes by attenuating abnormally activated FGFR3 signaling in achondroplasia.  

PubMed

Achondroplasia (ACH) is one of the most common skeletal dysplasias with short stature caused by gain-of-function mutations in FGFR3 encoding the fibroblast growth factor receptor 3. We used the drug repositioning strategy to identify an FDA-approved drug that suppresses abnormally activated FGFR3 signaling in ACH. We found that meclozine, an anti-histamine drug that has long been used for motion sickness, facilitates chondrocyte proliferation and mitigates loss of extracellular matrix in FGF2-treated rat chondrosarcoma (RCS) cells. Meclozine also ameliorated abnormally suppressed proliferation of human chondrosarcoma (HCS-2/8) cells that were infected with lentivirus expressing constitutively active mutants of FGFR3-K650E causing thanatophoric dysplasia, FGFR3-K650M causing SADDAN, and FGFR3-G380R causing ACH. Similarly, meclozine alleviated abnormally suppressed differentiation of ATDC5 chondrogenic cells expressing FGFR3-K650E and -G380R in micromass culture. We also confirmed that meclozine alleviates FGF2-mediated longitudinal growth inhibition of embryonic tibia in bone explant culture. Interestingly, meclozine enhanced growth of embryonic tibia in explant culture even in the absence of FGF2 treatment. Analyses of intracellular FGFR3 signaling disclosed that meclozine downregulates phosphorylation of ERK but not of MEK in FGF2-treated RCS cells. Similarly, meclozine enhanced proliferation of RCS cells expressing constitutively active mutants of MEK and RAF but not of ERK, which suggests that meclozine downregulates the FGFR3 signaling by possibly attenuating ERK phosphorylation. We used the C-natriuretic peptide (CNP) as a potent inhibitor of the FGFR3 signaling throughout our experiments, and found that meclozine was as efficient as CNP in attenuating the abnormal FGFR3 signaling. We propose that meclozine is a potential therapeutic agent for treating ACH and other FGFR3-related skeletal dysplasias. PMID:24324705

Matsushita, Masaki; Kitoh, Hiroshi; Ohkawara, Bisei; Mishima, Kenichi; Kaneko, Hiroshi; Ito, Mikako; Masuda, Akio; Ishiguro, Naoki; Ohno, Kinji

2013-01-01

174

Meclozine Facilitates Proliferation and Differentiation of Chondrocytes by Attenuating Abnormally Activated FGFR3 Signaling in Achondroplasia  

PubMed Central

Achondroplasia (ACH) is one of the most common skeletal dysplasias with short stature caused by gain-of-function mutations in FGFR3 encoding the fibroblast growth factor receptor 3. We used the drug repositioning strategy to identify an FDA-approved drug that suppresses abnormally activated FGFR3 signaling in ACH. We found that meclozine, an anti-histamine drug that has long been used for motion sickness, facilitates chondrocyte proliferation and mitigates loss of extracellular matrix in FGF2-treated rat chondrosarcoma (RCS) cells. Meclozine also ameliorated abnormally suppressed proliferation of human chondrosarcoma (HCS-2/8) cells that were infected with lentivirus expressing constitutively active mutants of FGFR3-K650E causing thanatophoric dysplasia, FGFR3-K650M causing SADDAN, and FGFR3-G380R causing ACH. Similarly, meclozine alleviated abnormally suppressed differentiation of ATDC5 chondrogenic cells expressing FGFR3-K650E and -G380R in micromass culture. We also confirmed that meclozine alleviates FGF2-mediated longitudinal growth inhibition of embryonic tibia in bone explant culture. Interestingly, meclozine enhanced growth of embryonic tibia in explant culture even in the absence of FGF2 treatment. Analyses of intracellular FGFR3 signaling disclosed that meclozine downregulates phosphorylation of ERK but not of MEK in FGF2-treated RCS cells. Similarly, meclozine enhanced proliferation of RCS cells expressing constitutively active mutants of MEK and RAF but not of ERK, which suggests that meclozine downregulates the FGFR3 signaling by possibly attenuating ERK phosphorylation. We used the C-natriuretic peptide (CNP) as a potent inhibitor of the FGFR3 signaling throughout our experiments, and found that meclozine was as efficient as CNP in attenuating the abnormal FGFR3 signaling. We propose that meclozine is a potential therapeutic agent for treating ACH and other FGFR3-related skeletal dysplasias. PMID:24324705

Matsushita, Masaki; Kitoh, Hiroshi; Ohkawara, Bisei; Mishima, Kenichi; Kaneko, Hiroshi; Ito, Mikako; Masuda, Akio; Ishiguro, Naoki; Ohno, Kinji

2013-01-01

175

Pharmacological modulation of pain-related brain activity during normal and central sensitization states in humans.  

PubMed

Abnormal processing of somatosensory inputs in the central nervous system (central sensitization) is the mechanism accounting for the enhanced pain sensitivity in the skin surrounding tissue injury (secondary hyperalgesia). Secondary hyperalgesia shares clinical characteristics with neurogenic hyperalgesia in patients with neuropathic pain. Abnormal brain responses to somatosensory stimuli have been found in patients with hyperalgesia as well as in normal subjects during experimental central sensitization. The aim of this study was to assess the effects of gabapentin, a drug effective in neuropathic pain patients, on brain processing of nociceptive information in normal and central sensitization states. Using functional magnetic resonance imaging (fMRI) in normal volunteers, we studied the gabapentin-induced modulation of brain activity in response to nociceptive mechanical stimulation of normal skin and capsaicin-induced secondary hyperalgesia. The dose of gabapentin was 1,800 mg per os, in a single administration. We found that (i) gabapentin reduced the activations in the bilateral operculoinsular cortex, independently of the presence of central sensitization; (ii) gabapentin reduced the activation in the brainstem, only during central sensitization; (iii) gabapentin suppressed stimulus-induced deactivations, only during central sensitization; this effect was more robust than the effect on brain activation. The observed drug-induced effects were not due to changes in the baseline fMRI signal. These findings indicate that gabapentin has a measurable antinociceptive effect and a stronger antihyperalgesic effect most evident in the brain areas undergoing deactivation, thus supporting the concept that gabapentin is more effective in modulating nociceptive transmission when central sensitization is present. PMID:16330766

Iannetti, G D; Zambreanu, L; Wise, R G; Buchanan, T J; Huggins, J P; Smart, T S; Vennart, W; Tracey, I

2005-12-13

176

High-Resolution Magnetic Resonance Microscopy and Diffusion Tensor Imaging to Assess Brain Structural Abnormalities in the Murine Mucopolysaccharidosis VII Model  

PubMed Central

High-resolution microscopic magnetic resonance imaging (?MRI) and diffusion tensor imaging (DTI) were performed to characterize brain structural abnormalities in a mouse model of mucopolysaccharidosis type VII (MPS VII). ?MRI demonstrated a decrease in the volume of anterior commissure and corpus callosum and a slight increase in the volume of the hippocampus in MPS VII vs. wild-type mice. DTI indices were analyzed in gray and white matter. In vivo and ex vivo DTI demonstrated significantly reduced fractional anisotropy in the anterior commissure, corpus callosum, external capsule and hippocampus in MPS VII vs. control brains. Significantly increased mean diffusivity was also found in the anterior commissure and corpus callosum from ex-vivo DTI. Significantly reduced linear anisotropy was observed from the hippocampus from in-vivo DTI, whereas significantly decreased planar anisotropy and spherical anisotropy were observed in the external capsule from only ex-vivo DTI. There were corresponding morphological differences in the brains of MPS VII mice by hematoxylin and eosin staining. Luxol fast blue staining demonstrated less intense staining of the corpus callosum and external capsule; myelin abnormalities in the corpus callosum were also demonstrated quantitatively in toluidine blue-stained sections and confirmed by electron microscopy. These results demonstrate the potential for ?MRI and DTI for quantitative assessment of brain pathology in murine models of brain diseases. PMID:24335527

Poptani, Harish; Kumar, Manoj; Nasrallah, Ilya M; Kim, Sungheon; Ittyerah, Ranjit; Pickup, Stephen; Li, Joel; Parente, Michael K; Wolfe, John H.

2014-01-01

177

Activation of a mobile robot through a brain computer interface  

Microsoft Academic Search

This work presents the development of a brain computer interface as an alternative communication channel to be used in Robotics. It encompasses the implementation of an electroencephalograph (EEG), as well as the development of all computational methods and necessary techniques to identify mental activities. The developed brain computer interface (BCI) is applied to activate the movements of a 120lb mobile

Alexandre Ormiga Galvão Barbosa; David Ronald Achanccaray; Marco A. Meggiolaro

2010-01-01

178

Brain activation associated with active and passive lower limb stepping  

PubMed Central

Reports about standardized and repeatable experimental procedures investigating supraspinal activation in patients with gait disorders are scarce in current neuro-imaging literature. Well-designed and executed tasks are important to gain insight into the effects of gait-rehabilitation on sensorimotor centers of the brain. The present study aims to demonstrate the feasibility of a novel imaging paradigm, combining the magnetic resonance (MR)-compatible stepping robot (MARCOS) with sparse sampling functional magnetic resonance imaging (fMRI) to measure task-related BOLD signal changes and to delineate the supraspinal contribution specific to active and passive stepping. Twenty-four healthy participants underwent fMRI during active and passive, periodic, bilateral, multi-joint, lower limb flexion and extension akin to human gait. Active and passive stepping engaged several cortical and subcortical areas of the sensorimotor network, with higher relative activation of those areas during active movement. Our results indicate that the combination of MARCOS and sparse sampling fMRI is feasible for the detection of lower limb motor related supraspinal activation. Activation of the anterior cingulate and medial frontal areas suggests motor response inhibition during passive movement in healthy participants. Our results are of relevance for understanding the neural mechanisms underlying gait in the healthy. PMID:25389396

Jaeger, Lukas; Marchal-Crespo, Laura; Wolf, Peter; Riener, Robert; Michels, Lars; Kollias, Spyros

2014-01-01

179

High Prevalence of Chronic Pituitary and Target-Organ Hormone Abnormalities after Blast-Related Mild Traumatic Brain Injury  

PubMed Central

Studies of traumatic brain injury from all causes have found evidence of chronic hypopituitarism, defined by deficient production of one or more pituitary hormones at least 1?year after injury, in 25–50% of cases. Most studies found the occurrence of posttraumatic hypopituitarism (PTHP) to be unrelated to injury severity. Growth hormone deficiency (GHD) and hypogonadism were reported most frequently. Hypopituitarism, and in particular adult GHD, is associated with symptoms that resemble those of PTSD, including fatigue, anxiety, depression, irritability, insomnia, sexual dysfunction, cognitive deficiencies, and decreased quality of life. However, the prevalence of PTHP after blast-related mild TBI (mTBI), an extremely common injury in modern military operations, has not been characterized. We measured concentrations of 12 pituitary and target-organ hormones in two groups of male US Veterans of combat in Iraq or Afghanistan. One group consisted of participants with blast-related mTBI whose last blast exposure was at least 1?year prior to the study. The other consisted of Veterans with similar military deployment histories but without blast exposure. Eleven of 26, or 42% of participants with blast concussions were found to have abnormal hormone levels in one or more pituitary axes, a prevalence similar to that found in other forms of TBI. Five members of the mTBI group were found with markedly low age-adjusted insulin-like growth factor-I (IGF-I) levels indicative of probable GHD, and three had testosterone and gonadotropin concentrations consistent with hypogonadism. If symptoms characteristic of both PTHP and PTSD can be linked to pituitary dysfunction, they may be amenable to treatment with hormone replacement. Routine screening for chronic hypopituitarism after blast concussion shows promise for appropriately directing diagnostic and therapeutic decisions that otherwise may remain unconsidered and for markedly facilitating recovery and rehabilitation. PMID:22347210

Wilkinson, Charles W.; Pagulayan, Kathleen F.; Petrie, Eric C.; Mayer, Cynthia L.; Colasurdo, Elizabeth A.; Shofer, Jane B.; Hart, Kim L.; Hoff, David; Tarabochia, Matthew A.; Peskind, Elaine R.

2011-01-01

180

Elevated serum ubiquitin carboxy-terminal hydrolase L1 is associated with abnormal blood-brain barrier function after traumatic brain injury.  

PubMed

Serum S100B elevations accurately reflect blood-brain barrier (BBB) damage. Because S100B is also present in peripheral tissues, release of this protein may not be specific to central nervous system (CNS) injury. Ubiquitin C-terminal hydrolase 1 (UCHL1), and phosphorylated neurofilament heavy chain (pNF-H) are found exclusively in neurons, but their relationship to BBB dysfunction has not been determined. The objective of this study was to determine the accuracy of serum UCHL1 and pNF-H as measures of BBB integrity after traumatic brain injury (TBI), to and compare them to S100B. We performed a prospective study of 16 patients with moderate to severe TBI (Glasgow Coma Scale [GCS] score ?12) and 6 patients with non-traumatic headache who had cerebrospinal fluid (CSF) collected by ventriculostomy or lumbar puncture (LP). Serum and CSF were collected at the time of LP for headache patients and at 12, 24, and 48?h after injury for TBI patients. BBB function was determined by calculating albumin quotients (Q(A)), where Q(A)=[albumin(CSF)]/[albumin(serum)]. S100B, UCHL1, and pNF-H were measured by enzyme-linked immunosorbent assay (ELISA). Pearson's correlation coefficient and area under the receiver operator characteristic (ROC) curve were used to determine relationships between serum markers and Q(A). At 12 hours after TBI, a significant relationship was found between Q(A) and serum UCHL1 concentrations (AUC=0.76; 95% CI 0.55,1.00), and between Q(A) and serum S100B concentrations (AUC=0.794; 95% CI 0.57,1.02). There was no significant relationship found between these markers and Q(A) at other time points, or between pNF-H and Q(A) at any time point. We conclude that serum concentrations of UCHL1 are associated with abnormal BBB status 12?h after moderate to severe TBI. This relationship is similar to that observed between serum S100B and Q(A,) despite the fact that S100B may be released from peripheral tissues after multi-trauma. We conclude that peripheral release of S100B after multi-trauma is probably negligible and that UCHL1 may have some utility to monitor BBB disruption following TBI. PMID:21428722

Blyth, Brian J; Farahvar, Arash; He, Hua; Nayak, Akshata; Yang, Cui; Shaw, Gerry; Bazarian, Jeffrey J

2011-12-01

181

Altered Spontaneous Brain Activity in Patients with Hemifacial Spasm: A Resting-State Functional MRI Study  

PubMed Central

Resting-state functional magnetic resonance imaging (fMRI) has been used to detect the alterations of spontaneous neuronal activity in various neurological and neuropsychiatric diseases, but rarely in hemifacial spasm (HFS), a nervous system disorder. We used resting-state fMRI with regional homogeneity (ReHo) analysis to investigate changes in spontaneous brain activity of patients with HFS and to determine the relationship of these functional changes with clinical features. Thirty patients with HFS and 33 age-, sex-, and education-matched healthy controls were included in this study. Compared with controls, HFS patients had significantly decreased ReHo values in left middle frontal gyrus (MFG), left medial cingulate cortex (MCC), left lingual gyrus, right superior temporal gyrus (STG) and right precuneus; and increased ReHo values in left precentral gyrus, anterior cingulate cortex (ACC), right brainstem, and right cerebellum. Furthermore, the mean ReHo value in brainstem showed a positive correlation with the spasm severity (r = 0.404, p = 0.027), and the mean ReHo value in MFG was inversely related with spasm severity in HFS group (r = -0.398, p = 0.028). This study reveals that HFS is associated with abnormal spontaneous brain activity in brain regions most involved in motor control and blinking movement. The disturbances of spontaneous brain activity reflected by ReHo measurements may provide insights into the neurological pathophysiology of HFS. PMID:25603126

Tu, Ye; Wei, Yongxu; Sun, Kun; Zhao, Weiguo; Yu, Buwei

2015-01-01

182

Spontaneous and task-evoked brain activity negatively interact  

PubMed Central

A widely held assumption is that spontaneous and task-evoked brain activity sum linearly, such that the recorded brain response in each single trial is the algebraic sum of the constantly changing ongoing activity and the stereotypical evoked activity. Using functional magnetic resonance imaging (fMRI) signals acquired from normal humans, we show that this assumption is invalid. Across widespread cortices, evoked activity interacts negatively with ongoing activity, such that higher prestimulus baseline results in less activation or more deactivation. As a consequence of this negative interaction, trial-to-trial variability of cortical activity decreases following stimulus onset. We further show that variability reduction follows overlapping but distinct spatial pattern from that of task activation/deactivation and it contains behaviorally relevant information. These results favor an alternative perspective to the traditional dichotomous framework of ongoing and evoked activity – one that views the brain as a nonlinear dynamical system whose trajectory is tighter when performing a task; further, incoming sensory stimuli modulate the brain’s activity in a manner that depends on its initial state. We propose that across-trial variability may provide a new approach to brain mapping in the context of cognitive experiments. PMID:23486941

He, Biyu J.

2013-01-01

183

Reduced activities of thiamine-dependent enzymes in the brains and peripheral tissues of patients with Alzheimer's disease.  

PubMed

A report of cell loss in the nucleus basalis of Meynert in patients with Wernicke-Korsakoff disease prompted the examination of thiamine pyrophosphate (TPP)-dependent enzymes in the brain and peripheral tissues of patients with Alzheimer's disease. In these brains, the activities of the 2-ketoglutarate dehydrogenase complex were reduced more than 75% and those of transketolase more than 45%. Decreases occurred in histologically damaged and in relatively undamaged areas. Small but statistically significant abnormalities of transketolase, but not of 2-ketoglutarate dehydrogenase complex, were identified in red blood cells and cultured fibroblasts. Previous studies have shown deficiencies in the brain and variable effects in peripheral tissues on another TPP-dependent enzyme--the pyruvate dehydrogenase complex. Activities of TPP-dependent enzymes appear to be deficient in the brain and perhaps in some peripheral tissues in patients with Alzheimer's disease. PMID:3395256

Gibson, G E; Sheu, K F; Blass, J P; Baker, A; Carlson, K C; Harding, B; Perrino, P

1988-08-01

184

PHYSICAL ACTIVITY, INFLAMMATION, AND VOLUME OF THE AGING BRAIN  

PubMed Central

Physical activity influences inflammation, and both affect brain structure and Alzheimer’s disease (AD) risk. We hypothesized that older adults with greater reported physical activity intensity and lower serum levels of the inflammatory marker tumor necrosis factor ? (TNF?) would have larger regional brain volumes on subsequent magnetic resonance imaging (MRI) scans. In 43 cognitively intact older adults (79.3 ± 4.8 years) and 39 patients with AD (81.9 ± 5.1 years at the time of MRI) participating in the Cardiovascular Health Study, we examined year-1 reported physical activity intensity, year-5 blood serum TNF? measures, and year-9 volumetric brain MRI scans. We examined how prior physical activity intensity and TNF? related to subsequent total and regional brain volumes. Physical activity intensity was measured using the modified Minnesota Leisure Time Physical Activities questionnaire at year 1 of the study, when all subjects included here were cognitively intact. Stability of measures was established for exercise intensity over 9 years and TNF? over 3 years in a subset of subjects who had these measurements at multiple time points. When considered together, more intense physical activity intensity and lower serum TNF? were both associated with greater total brain volume on follow-up MRI scans. TNF?, but not physical activity, was associated with regional volumes of the inferior parietal lobule, a region previously associated with inflammation in AD patients. Physical activity and TNF? may independently influence brain structure in older adults. PMID:24836855

BRASKIE, M. N.; BOYLE, C. P.; RAJAGOPALAN, P.; GUTMAN, B. A.; TOGA, A. W.; RAJI, C. A.; TRACY, R. P.; KULLER, L. H.; BECKER, J. T.; LOPEZ, O. L.; THOMPSON, P. M.

2014-01-01

185

Stress in Pregnancy Activates Neurosteroid Production in the Fetal Brain  

Microsoft Academic Search

Neurosteroids such as allopregnanolone are potent agonists at the GABAA receptor and suppress the fetal CNS activity. These steroids are synthesized in the fetal brain either from cholesterol or from circulating precursors derived from the placenta. The concentrations of allopregnanolone are remarkably high in the fetal brain and rise further in response to acute hypoxic stress, induced by constriction of

Jonathan J. Hirst; Tamara Yawno; Phuong Nguyen; David W. Walker

2006-01-01

186

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

E-print Network

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

Miall, Chris

187

Three-Dimensional Electrical Impedance Tomography of Human Brain Activity  

Microsoft Academic Search

Regional cerebral blood flow and blood volume changes that occur during human brain activity will change the local impedance of that cortical area, as blood has a lower impedance than that of brain. Theoretically, such impedance changes could be measured from scalp electrodes and reconstructed into images of the internal impedance of the head. Electrical Impedance Tomography (EIT) is a

Tom Tidswell; Adam Gibson; Richard H. Bayford; David S. Holder

2001-01-01

188

Peers increase adolescent risk taking by enhancing activity in the brain’s reward circuitry  

PubMed Central

The presence of peers increases risk taking among adolescents but not adults. We posited that the presence of peers may promote adolescent risk taking by sensitizing brain regions associated with the anticipation of potential rewards. Using fMRI, we measured brain activity in adolescents, young adults, and adults as they made decisions in a simulated driving task. Participants completed one task block while alone, and one block while their performance was observed by peers in an adjacent room. During peer observation blocks, adolescents selectively demonstrated greater activation in reward-related brain regions, including the ventral striatum and orbitofrontal cortex, and activity in these regions predicted subsequent risk taking. Brain areas associated with cognitive control were less strongly recruited by adolescents than adults, but activity in the cognitive control system did not vary with social context. Results suggest that the presence of peers increases adolescent risk taking by heightening sensitivity to the potential reward value of risky decisions. PMID:21499511

Chein, Jason; Albert, Dustin; O’Brien, Lia; Uckert, Kaitlyn; Steinberg, Laurence

2010-01-01

189

Changes of Enzyme Activities and Compositions of Abnormal Fruiting Bodies Grown under Artificial Environmental Conditions in Pleurotus ostreatus.  

PubMed

This study investigated the biochemical changes of abnormal fruiting bodies grown under artificial environmental conditions in P. ostreatus. Abnormal mushroom growth during cultivation damages the production of good quality mushroom. This study showed that different environmental conditions produced morphological changes in the fruiting bodies of P. ostreatus. The fruiting bodies with morphological changes were collected and examined for differences in biochemical properties, enzyme activities, and carbohydrates composition. The enzyme activities assay showed that glucanase and chitinase activities decreased when the temperature was below or above the optimum cultivation temperature for P. ostreatus. The biochemical compositions of the abnormal mushroom were significantly different from the normal fruiting bodies. It was suggested that the changes in the biochemical composition of abnormal mushroom were caused by the unfavorable environmental conditions during mushroom cultivation. PMID:24049471

Jang, Kab Yeul; Cho, Soo Muk; June, Chang Sung; Weon, Hang Yeon; Park, Jeong Sik; Choi, Sun Gyu; Cheong, Jong Chun; Sung, Jae Mo

2005-03-01

190

CD8+ Lymphocyte Depletion without SIV Infection does not Produce Metabolic Changes or Pathological Abnormalities in the Rhesus Macaque Brain  

PubMed Central

Background Simian immunodeficiency virus (SIV) infection and persistent CD8+ lymphocyte depletion rapidly leads to encephalitis and neuronal injury. The objective of this study is to confirm that CD8-depletion alone does not affect brain pathology in the absence of SIV infection. Methods Four rhesus macaques were monitored by proton magnetic resonance spectroscopy (1H-MRS) before and biweekly after anti-CD8 antibody treatment for eight weeks and compared to four SIV-infected animals. Postmortem immunohistochemistry was performed on these eight animals and compared to six uninfected, non-CD8-depleted controls. Results CD8-depleted animals showed stable metabolite levels and revealed no neuronal injury, astrogliosis or microglial activation in contrast to SIV-infected animals. Conclusions Alterations observed in MRS and lesions in this accelerated model of neuroAIDS result from unrestricted viral expansion in the setting of immunodeficiency rather than from CD8+ lymphocyte depletion alone. PMID:21463330

Ratai, Eva-Maria; Pilkenton, Sarah; He, Julian; Fell, Robert; Bombardier, Jeffrey P.; Joo, Chan-Gyu; Lentz, Margaret R.; Kim, Woong-Ki; Burdo, Tricia H.; Autissier, Patrick; Annamalai, Lakshmanan; Curran, Elizabeth; O'Neil, Shawn; Westmoreland, Susan V.; Williams, Kenneth. C.; Masliah, Eliezer; González, R. Gilberto

2011-01-01

191

What is the importance of abnormal “background” activity in seizure generation?  

PubMed Central

Investigations of interictal epileptiform spikes and seizures have played a central role in the study of epilepsy. The background EEG activity, however, has received less attention. In this chapter we discuss the characteristic features of the background activity of the brain when individuals are at rest and awake (resting wake) and during sleep. The characteristic rhythms of the background EEG are presented, and the presence of 1/f ? behavior of the EEG power spectral density is discussed and its possible origin and functional significance. The interictal EEG findings of focal epilepsy and the impact of interictal epileptiform spikes on cognition are also discussed. PMID:25012365

Staba, Richard; Worrell, Gregory

2014-01-01

192

Nanotools for Neuroscience and Brain Activity Mapping  

E-print Network

Neuroscience is at a crossroads. Great effort is being invested into deciphering specific neural interactions and circuits. At the same time, there exist few general theories or principles that explain brain function. We ...

Alivisatos, A. Paul

193

Brain-Computer Interfaces (BCI): Restoration of Movement and Thought from Neuroelectric and Metabolic Brain Activity  

Microsoft Academic Search

This chapter provides an overview of the scientific and clinical progress in the development of non-invasive and invasive\\u000a brain-computer interfaces (BCI). BCI uses electric, magnetic or metabolic brain activity for the activation and control of\\u000a external devices and computers. Clinically, until now it has been successfully used as a communication system for totally\\u000a paralyzed patients (“locked-in patients”), in restoration of

Surjo R. Soekadar; Klaus Haagen; Niels Birbaumer

194

Abnormal high-density lipoprotein induces endothelial dysfunction via activation of Toll-like receptor-2.  

PubMed

Endothelial injury and dysfunction (ED) represent a link between cardiovascular risk factors promoting hypertension and atherosclerosis, the leading cause of death in Western populations. High-density lipoprotein (HDL) is considered antiatherogenic and known to prevent ED. Using HDL from children and adults with chronic kidney dysfunction (HDL(CKD)), a population with high cardiovascular risk, we have demonstrated that HDL(CKD) in contrast to HDL(Healthy) promoted endothelial superoxide production, substantially reduced nitric oxide (NO) bioavailability, and subsequently increased arterial blood pressure (ABP). We have identified symmetric dimethylarginine (SDMA) in HDL(CKD) that causes transformation from physiological HDL into an abnormal lipoprotein inducing ED. Furthermore, we report that HDL(CKD) reduced endothelial NO availability via toll-like receptor-2 (TLR-2), leading to impaired endothelial repair, increased proinflammatory activation, and ABP. These data demonstrate how SDMA can modify the HDL particle to mimic a damage-associated molecular pattern that activates TLR-2 via a TLR-1- or TLR-6-coreceptor-independent pathway, linking abnormal HDL to innate immunity, ED, and hypertension. PMID:23477738

Speer, Thimoteus; Rohrer, Lucia; Blyszczuk, Przemyslaw; Shroff, Rukshana; Kuschnerus, Kira; Kränkel, Nicolle; Kania, Gabriela; Zewinger, Stephen; Akhmedov, Alexander; Shi, Yi; Martin, Tina; Perisa, Damir; Winnik, Stephan; Müller, Maja F; Sester, Urban; Wernicke, Gabriel; Jung, Andreas; Gutteck, Ursula; Eriksson, Urs; Geisel, Jürgen; Deanfield, John; von Eckardstein, Arnold; Lüscher, Thomas F; Fliser, Danilo; Bahlmann, Ferdinand H; Landmesser, Ulf

2013-04-18

195

Spatial heterogeneity analysis of brain activation in fMRI  

PubMed Central

In many brain diseases it can be qualitatively observed that spatial patterns in blood oxygenation level dependent (BOLD) activation maps appear more (diffusively) distributed than in healthy controls. However, measures that can quantitatively characterize this spatial distributiveness in individual subjects are lacking. In this study, we propose a number of spatial heterogeneity measures to characterize brain activation maps. The proposed methods focus on different aspects of heterogeneity, including the shape (compactness), complexity in the distribution of activated regions (fractal dimension and co-occurrence matrix), and gappiness between activated regions (lacunarity). To this end, functional MRI derived activation maps of a language and a motor task were obtained in language impaired children with (Rolandic) epilepsy and compared to age-matched healthy controls. Group analysis of the activation maps revealed no significant differences between patients and controls for both tasks. However, for the language task the activation maps in patients appeared more heterogeneous than in controls. Lacunarity was the best measure to discriminate activation patterns of patients from controls (sensitivity 74%, specificity 70%) and illustrates the increased irregularity of gaps between activated regions in patients. The combination of heterogeneity measures and a support vector machine approach yielded further increase in sensitivity and specificity to 78% and 80%, respectively. This illustrates that activation distributions in impaired brains can be complex and more heterogeneous than in normal brains and cannot be captured fully by a single quantity. In conclusion, heterogeneity analysis has potential to robustly characterize the increased distributiveness of brain activation in individual patients. PMID:25161893

Gupta, Lalit; Besseling, René M.H.; Overvliet, Geke M.; Hofman, Paul A.M.; de Louw, Anton; Vaessen, Maarten J.; Aldenkamp, Albert P.; Ulman, Shrutin; Jansen, Jacobus F.A.; Backes, Walter H.

2014-01-01

196

Systems/Circuits The Autonomic Brain: An Activation Likelihood Estimation  

E-print Network

Systems/Circuits The Autonomic Brain: An Activation Likelihood Estimation Meta-Analysis for Central, Massachusetts General Hospital, Charlestown, Massachusetts 02129 The autonomic nervous system (ANS) is of paramount importance for daily life. Its regulatory action on respiratory, cardiovascular, digestive

Napadow, Vitaly

197

Abnormal microglial activation in the Cstb(-/-) mouse, a model for progressive myoclonus epilepsy, EPM1.  

PubMed

Progressive myoclonus epilepsy of Unverricht-Lundborg type (EPM1) is an autosomal-recessively inherited neurodegenerative disorder characterized by severely incapacitating myoclonus, seizures, and ataxia, and caused by loss-of-function mutations in the cystatin B gene (CSTB). A central neuropathological finding in the Cstb(-/-) mouse, an animal model for EPM1, is early microglial activation, which precedes astroglial activation, neuronal loss, and onset of myoclonus, thus implying a critical role for microglia in EPM1 pathogenesis. Here, we characterized phenotypic and functional properties of microglia from Cstb(-/-) mice utilizing brain tissue, microglia directly isolated from the brain, and primary microglial cultures. Our results show significantly higher Cstb mRNA expression in microglia than in neurons and astrocytes. In Cstb(-/-) mouse brain, expression of the inflammatory marker p-p38 MAPK and the proportion of both pro-inflammatory M1 and anti-inflammatory M2 microglia is higher than in control mice. Moreover, M1/M2 polarization of microglia in presymptomatic Cstb(-/-) mice is, compared to control mice, skewed towards M2 type at postnatal day 14 (P14), but towards M1 type at P30, a time point associated with onset of myoclonus. At this age, the high expression of both pro-inflammatory inducible nitric oxide synthase (iNOS) and anti-inflammatory arginase 1 (ARG1) in Cstb(-/-) mouse cortex is accompanied by the presence of peripheral immune cells. Consistently, activated Cstb(-/-) microglia show elevated chemokine release and chemotaxis. However, their MHCII surface expression is suppressed. Taken together, our results link CSTB deficiency to neuroinflammation with early activation and dysfunction of microglia and will open new avenues for therapeutic interventions for EPM1. GLIA 2015;63:400-411. PMID:25327891

Okuneva, Olesya; Körber, Inken; Li, Zhilin; Tian, Li; Joensuu, Tarja; Kopra, Outi; Lehesjoki, Anna-Elina

2015-03-01

198

Reversal of brain metabolic abnormalities following treatment of AIDS dementia complex with 3'-azido-2',3'-dideoxythymidine (AZT, zidovudine): a PET-FDG study  

SciTech Connect

Brain glucose metabolism was evaluated in four patients with acquired immunodeficiency syndrome (AIDS) dementia complex using (/sup 18/F)fluorodeoxyglucose (FDG) and positron emission tomography (PET) scans at the beginning of therapy with 3'-azido-2',3'-dideoxythymidine (AZT, zidovudine), and later in the course of therapy. In two patients, baseline, large focal cortical abnormalities of glucose utilization were reversed during the course of therapy. In the other two patients, the initial PET study did not reveal pronounced focal alterations, while the post-treatment scans showed markedly increased cortical glucose metabolism. The improved cortical glucose utilization was accompanied in all patients by immunologic and neurologic improvement. PET-FDG studies can detect cortical metabolic abnormalities associated with AIDS dementia complex, and may be used to monitor the metabolic improvement in response to AZT treatment.

Brunetti, A.; Berg, G.; Di Chiro, G.; Cohen, R.M.; Yarchoan, R.; Pizzo, P.A.; Broder, S.; Eddy, J.; Fulham, M.J.; Finn, R.D.

1989-05-01

199

Metabolic pathways and activity-dependent modulation of glutamate concentration in the human brain  

PubMed Central

Glutamate is one of the most versatile molecules present in the human brain, involved in protein synthesis, energy production, ammonia detoxification, and transport of reducing equivalents. Aside from these critical metabolic roles, glutamate plays a major part in brain function, being not only the most abundant excitatory neurotransmitter, but also the precursor for ?-aminobutyric acid (GABA), the predominant inhibitory neurotransmitter. Regulation of glutamate levels is pivotal for normal brain function, as abnormal extracellular concentration of glutamate can lead to impaired neurotransmission, neurodegeneration and even neuronal death. Understanding how the neuron-astrocyte functional and metabolic interactions modulate glutamate concentration during different activation status and under physiological and pathological conditions is a challenging task, and can only be tentatively estimated from current literature. In this paper, we focus on describing the various metabolic pathways which potentially affect glutamate concentration in the brain, and emphasize which ones are likely to produce the variations in glutamate concentration observed during enhanced neuronal activity in human studies. PMID:22846967

Mangia, Silvia; Giove, Federico; DiNuzzo, Mauro

2012-01-01

200

Neurotransmitter receptor-mediated activation of G-proteins in brains of suicide victims with mood disorders: selective supersensitivity of ?2A-adrenoceptors  

Microsoft Academic Search

Abnormalities in the density of neuroreceptors that regulate norepinephrine and serotonin release have been repeatedly reported in brains of suicide victims with mood disorders. Recently, the modulation of the [35S]GTP?S binding to G-proteins has been introduced as a suitable measure of receptor activity in postmortem human brain. The present study sought to evaluate the function of several G-protein coupled receptors

J González-Maeso; R Rodríguez-Puertas; J J Meana; J A García-Sevilla; J Guimón

2002-01-01

201

Early Risk, Attention, and Brain Activation in Adolescents Born Preterm  

ERIC Educational Resources Information Center

The relations among early cumulative medical risk, cumulative environmental risk, attentional control, and brain activation were assessed in 15-16-year-old adolescents who were born preterm. Functional magnetic resonance imaging found frontal, temporal, and parietal cortex activation during an attention task with greater activation of the left…

Carmody, Dennis P.; Bendersky, Margaret; Dunn, Stanley M.; DeMarco, J. Kevin; Hegyi, Thomas; Hiatt, Mark; Lewis, Michael

2006-01-01

202

Abnormal dynamics of activation of object use information in apraxia: evidence from eyetracking.  

PubMed

Action representations associated with object use may be incidentally activated during visual object processing, and the time course of such activations may be influenced by lexical-semantic context (e.g., Lee, Middleton, Mirman, Kalénine, & Buxbaum (2012). Journal of Experimental Psychology: Human Perception and Performance, 39(1), 257-270). In this study we used the "visual world" eye-tracking paradigm to examine whether a deficit in producing skilled object-use actions (apraxia) is associated with abnormalities in incidental activation of action information, and assessed the neuroanatomical substrates of any such deficits. Twenty left hemisphere stroke patients, ten of whom were apraxic, performed a task requiring identification of a named object in a visual display containing manipulation-related and unrelated distractor objects. Manipulation relationships among objects were not relevant to the identification task. Objects were cued with neutral ("S/he saw the…."), or action-relevant ("S/he used the….") sentences. Non-apraxic participants looked at use-related non-target objects significantly more than at unrelated non-target objects when cued both by neutral and action-relevant sentences, indicating that action information is incidentally activated. In contrast, apraxic participants showed delayed activation of manipulation-based action information during object identification when cued by neutral sentences. The magnitude of delayed activation in the neutral sentence condition was reliably predicted by lower scores on a test of gesture production to viewed objects, as well as by lesion loci in the inferior parietal and posterior temporal lobes. However, when cued by a sentence containing an action verb, apraxic participants showed fixation patterns that were statistically indistinguishable from non-apraxic controls. In support of grounded theories of cognition, these results suggest that apraxia and temporal-parietal lesions may be associated with abnormalities in incidental activation of action information from objects. Further, they suggest that the previously-observed facilitative role of action verbs in the retrieval of object-related action information extends to participants with apraxia. PMID:24746946

Lee, Chia-Iin; Mirman, Daniel; Buxbaum, Laurel J

2014-07-01

203

Brain death management: Keystone of transplantation activity  

Microsoft Academic Search

DURING the 5 past years, harvest of organs from cadaver sources has been decreasing in Lyon University Hospital Center (Lyon CHU) while it remained stable in the whole France Center East Region (R3) (Table 1).Diagnoses of brain death and organ harvest tend to be performed more often in local district hospitals in order to shorten the procedure and avoid transferring

M. Bret; B. Coronel; O. Vinot; J. F. Moskovtchenko

1997-01-01

204

A Battery-Powered Activity-Dependent Intracortical Microstimulation IC for Brain-Machine-Brain Interface  

Microsoft Academic Search

This paper describes an activity-dependent intracor- tical microstimulation (ICMS) system-on-chip (SoC) that converts extracellular neural spikes recorded from one brain region to electrical stimuli delivered to another brain region in real time in vivo. The 10.9-mm SoC incorporates two identical 4-channel modules, each comprising an analog recording front-end with total input noise voltage of 3.12 V and noise efficiency factor

Meysam Azin; David J. Guggenmos; Scott Barbay; Randolph J. Nudo; Pedram Mohseni

2011-01-01

205

[Cause of abnormal acidity of lysozyme ionogenic active center groups at cell wall lysis].  

PubMed

pH-Dependence of the kinetic parameters of Micrococcus lysodeicticus cell lysis under the action of the protein hen egg lysozyme at the pH 6.9-10.0 at 25 and 37 degrees C has been investigated. The pKb effective values for the lysozyme catalytic activity controlling group have been calculated. The DeltaHion value indicates that this group is the carboxyl one though its pK (9.15 at 25 degrees C) is found far for the limit of the carboxyl groups pK values. The cause of this abnormal pK values is supposed to be the strong negative charge of the bacterial cell wall. As a result the enzyme that catalyzes the hydrolysis ofcopolymer N-acetylglucosamine--N-acetylmuramic acid acts in the high acidity microenvironment. PMID:22332358

Smotrov, O I; Borzenkov, V M; Surovtsev, V I

2011-01-01

206

Personality traits and its association with resting regional brain activity.  

PubMed

The association between personality and resting brain activity was investigated. Personality was assessed using the NEO-Five-factor Inventory (NEO-FFI) and resting brain activity was indexed by eyes closed EEG spectral magnitude from four frequency bands over the entire cortex. Results suggest that there are differences between males and females in the NEO-FFI personality traits. The NEO FFI traits were associated with lower frequency brain activity in both males and females. Mild significant and consistent associations were found between delta and theta activity across all cortical regions with Extraversion and Conscientiousness. There were few associations between personality traits and alpha and beta activity, this was shown in males only. Fewer associations between personality and faster frequency bands such as alpha may be due to the methodological problem of using fixed alpha bands. Multiple regression analyses showed that individual alpha frequencies had a greater contribution to personality traits than fixed band alpha waves. PMID:16019096

Tran, Yvonne; Craig, Ashley; Boord, Peter; Connell, Kathy; Cooper, Nicholas; Gordon, Evian

2006-06-01

207

Abnormal blood–brain barrier permeability in normal appearing white matter in multiple sclerosis investigated by MRI???  

PubMed Central

Objectives To investigate whether blood–brain barrier (BBB) permeability is disrupted in normal appearing white matter in MS patients, when compared to healthy controls and whether it is correlated with MS clinical characteristics. Methods Dynamic contrast-enhanced MRI was used to measure BBB permeability in 27 patients with MS and compared to 24 matched healthy controls. Results Permeability measured as Ktrans was significantly higher in periventricular normal appearing white matter (NAWM) and thalamic gray matter in MS patients when compared to healthy controls, with periventricular NAWM showing the most pronounced difference. Recent relapse coincided with significantly higher permeability in periventricular NAWM, thalamic gray matter, and MS lesions. Immunomodulatory treatment and recent relapse were significant predictors of permeability in MS lesions and periventricular NAWM. Our results suggest that after an MS relapse permeability gradually decreases, possibly an effect of immunomodulatory treatment. Conclusions Our results emphasize the importance of BBB pathology in MS, which we find to be most prominent in the periventricular NAWM, an area prone to development of MS lesions. Both the facts that recent relapse appears to cause widespread BBB disruption and that immunomodulatory treatment seems to attenuate this effect indicate that BBB permeability is intricately linked to the presence of MS relapse activity. This may reveal further insights into the pathophysiology of MS. PMID:24371801

Cramer, S.P.; Simonsen, H.; Frederiksen, J.L.; Rostrup, E.; Larsson, H.B.W.

2013-01-01

208

[Need-information organization of brain activity].  

PubMed

Experimental results and literature data point to the leading role of four brain structures in the genesis of emotional states and in the organization of goal directed behaviour. Owing to the functioning of the frontal parts of the neocortex behaviour is oriented to signals with a high probability of their reinforcement, and owing to the hypothalamus--to satisfaction of the dominant need. Unlike the neocortex the hippocampus is necessary for reactions to signals of lowly probable events, which is typical of emotionally exicted brain. The amygdala complx participates in creation of a balance, a dynamic co-existence between completing needs (motivations) and corresponding emotions. As a result, behaviour becomes more plastic and adequate to the given situation. PMID:473899

Simonov, P V

1979-01-01

209

In vivo recordings of brain activity using organic transistors  

PubMed Central

In vivo electrophysiological recordings of neuronal circuits are necessary for diagnostic purposes and for brain-machine interfaces. Organic electronic devices constitute a promising candidate because of their mechanical flexibility and biocompatibility. Here we demonstrate the engineering of an organic electrochemical transistor embedded in an ultrathin organic film designed to record electrophysiological signals on the surface of the brain. The device, tested in vivo on epileptiform discharges, displayed superior signal-to-noise ratio due to local amplification compared with surface electrodes. The organic transistor was able to record on the surface low-amplitude brain activities, which were poorly resolved with surface electrodes. This study introduces a new class of biocompatible, highly flexible devices for recording brain activity with superior signal-to-noise ratio that hold great promise for medical applications. PMID:23481383

Khodagholy, Dion; Doublet, Thomas; Quilichini, Pascale; Gurfinkel, Moshe; Leleux, Pierre; Ghestem, Antoine; Ismailova, Esma; Hervé, Thierry; Sanaur, Sébastien; Bernard, Christophe; Malliaras, George G.

2013-01-01

210

Human brain activity with functional NIR optical imager  

NASA Astrophysics Data System (ADS)

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

Luo, Qingming

2001-08-01

211

Detection of abnormal cardiac activity using principal component analysis--a theoretical study.  

PubMed

Electrogram-guided ablation has been recently developed for allowing better detection and localization of abnormal atrial activity that may be the source of arrhythmogeneity. Nevertheless, no clear indication for the benefit of using electrograms guided ablation over empirical ablation was established thus far, and there is a clear need of improving the localization of cardiac arrhythmogenic targets for ablation. In this paper, we propose a new approach for detection and localization of irregular cardiac activity during ablation procedures that is based on dimension reduction algorithms and principal component analysis (PCA). Using an 8×8 electrode array, our method produces manifolds that allow easy visualization and detection of possible arrhythmogenic ablation targets characterized by irregular conduction. We employ mathematical modeling and computer simulations to demonstrate the feasibility of the new approach for two well established arrhythmogenic sources for irregular conduction--spiral waves and patchy fibrosis. Our results show that the PCA method can differentiate between focal ectopic activity and spiral wave activity, as these two types of activity produce substantially different manifold shapes. Moreover, the technique allows the detection of spiral wave cores and their general meandering and drifting pattern. Fibrotic patches larger than 2 mm(2) could also be visualized using the PCA method, both for quiescent atrial tissue and for tissue exhibiting spiral wave activity. We envision that this method, contingent to further numerical and experimental validation studies in more complex, realistic geometrical configurations and with clinical data, can improve existing atrial ablation mapping capabilities, thus increasing success rates and optimizing arrhythmia management. PMID:25073163

Greisas, Ariel; Zafrir, Zohar; Zlochiver, Sharon

2015-01-01

212

Consistent abnormalities in metabolic network activity in idiopathic rapid eye movement sleep behaviour disorder.  

PubMed

Rapid eye movement sleep behaviour disorder has been evaluated using Parkinson's disease-related metabolic network. It is unknown whether this disorder is itself associated with a unique metabolic network. 18F-fluorodeoxyglucose positron emission tomography was performed in 21 patients (age 65.0±5.6 years) with idiopathic rapid eye movement sleep behaviour disorder and 21 age/gender-matched healthy control subjects (age 62.5±7.5 years) to identify a disease-related pattern and examine its evolution in 21 hemi-parkinsonian patients (age 62.6±5.0 years) and 16 moderate parkinsonian patients (age 56.9±12.2 years). We identified a rapid eye movement sleep behaviour disorder-related metabolic network characterized by increased activity in pons, thalamus, medial frontal and sensorimotor areas, hippocampus, supramarginal and inferior temporal gyri, and posterior cerebellum, with decreased activity in occipital and superior temporal regions. Compared to the healthy control subjects, network expressions were elevated (P<0.0001) in the patients with this disorder and in the parkinsonian cohorts but decreased with disease progression. Parkinson's disease-related network activity was also elevated (P<0.0001) in the patients with rapid eye movement sleep behaviour disorder but lower than in the hemi-parkinsonian cohort. Abnormal metabolic networks may provide markers of idiopathic rapid eye movement sleep behaviour disorder to identify those at higher risk to develop neurodegenerative parkinsonism. PMID:25338949

Wu, Ping; Yu, Huan; Peng, Shichun; Dauvilliers, Yves; Wang, Jian; Ge, Jingjie; Zhang, Huiwei; Eidelberg, David; Ma, Yilong; Zuo, Chuantao

2014-12-01

213

Brain modularity controls the critical behavior of spontaneous activity  

NASA Astrophysics Data System (ADS)

The human brain exhibits a complex structure made of scale-free highly connected modules loosely interconnected by weaker links to form a small-world network. These features appear in healthy patients whereas neurological diseases often modify this structure. An important open question concerns the role of brain modularity in sustaining the critical behaviour of spontaneous activity. Here we analyse the neuronal activity of a model, successful in reproducing on non-modular networks the scaling behaviour observed in experimental data, on a modular network implementing the main statistical features measured in human brain. We show that on a modular network, regardless the strength of the synaptic connections or the modular size and number, activity is never fully scale-free. Neuronal avalanches can invade different modules which results in an activity depression, hindering further avalanche propagation. Critical behaviour is solely recovered if inter-module connections are added, modifying the modular into a more random structure.

Russo, R.; Herrmann, H. J.; de Arcangelis, L.

2014-03-01

214

Synchronous brain activity across individuals underlies shared psychological perspectives.  

PubMed

For successful communication, we need to understand the external world consistently with others. This task requires sufficiently similar cognitive schemas or psychological perspectives that act as filters to guide the selection, interpretation and storage of sensory information, perceptual objects and events. Here we show that when individuals adopt a similar psychological perspective during natural viewing, their brain activity becomes synchronized in specific brain regions. We measured brain activity with functional magnetic resonance imaging (fMRI) from 33 healthy participants who viewed a 10-min movie twice, assuming once a 'social' (detective) and once a 'non-social' (interior decorator) perspective to the movie events. Pearson's correlation coefficient was used to derive multisubject voxelwise similarity measures (inter-subject correlations; ISCs) of functional MRI data. We used k-nearest-neighbor and support vector machine classifiers as well as a Mantel test on the ISC matrices to reveal brain areas wherein ISC predicted the participants' current perspective. ISC was stronger in several brain regions--most robustly in the parahippocampal gyrus, posterior parietal cortex and lateral occipital cortex--when the participants viewed the movie with similar rather than different perspectives. Synchronization was not explained by differences in visual sampling of the movies, as estimated by eye gaze. We propose that synchronous brain activity across individuals adopting similar psychological perspectives could be an important neural mechanism supporting shared understanding of the environment. PMID:24936687

Lahnakoski, Juha M; Glerean, Enrico; Jääskeläinen, Iiro P; Hyönä, Jukka; Hari, Riitta; Sams, Mikko; Nummenmaa, Lauri

2014-10-15

215

Brain activity and medical diagnosis: an EEG study  

PubMed Central

Background Despite new brain imaging techniques that have improved the study of the underlying processes of human decision-making, to the best of our knowledge, there have been very few studies that have attempted to investigate brain activity during medical diagnostic processing. We investigated brain electroencephalography (EEG) activity associated with diagnostic decision-making in the realm of veterinary medicine using X-rays as a fundamental auxiliary test. EEG signals were analysed using Principal Components (PCA) and Logistic Regression Analysis Results The principal component analysis revealed three patterns that accounted for 85% of the total variance in the EEG activity recorded while veterinary doctors read a clinical history, examined an X-ray image pertinent to a medical case, and selected among alternative diagnostic hypotheses. Two of these patterns are proposed to be associated with visual processing and the executive control of the task. The other two patterns are proposed to be related to the reasoning process that occurs during diagnostic decision-making. Conclusions PCA analysis was successful in disclosing the different patterns of brain activity associated with hypothesis triggering and handling (pattern P1); identification uncertainty and prevalence assessment (pattern P3), and hypothesis plausibility calculation (pattern P2); Logistic regression analysis was successful in disclosing the brain activity associated with clinical reasoning success, and together with regression analysis showed that clinical practice reorganizes the neural circuits supporting clinical reasoning. PMID:24083668

2013-01-01

216

Males and females differ in brain activation during cognitive tasks  

Microsoft Academic Search

To examine the effect of gender on regional brain activity, we utilized functional magnetic resonance imaging (fMRI) during a motor task and three cognitive tasks; a word generation task, a spatial attention task, and a working memory task in healthy male (n = 23) and female (n = 10) volunteers. Functional data were examined for group differences both in the number of pixels activated,

Emily C. Bell; Morgan C. Willson; Alan H. Wilman; Sanjay Dave; Peter H. Silverstone

2006-01-01

217

Sequential relationships between grey matter and white matter atrophy and brain metabolic abnormalities in early Alzheimer's disease  

E-print Network

abnormalities in early Alzheimer's disease Nicolas Villain, PhD1 , Marine Fouquet, MSc1 , Jean-Claude Baron, MD3 Alzheimer's disease Keywords: Alzheimers disease, MRI/fMRI, PET imaging, white matter, hippocampus-matter tract disruption are well-described early macroscopic events in Alzheimers disease. The relationships

Boyer, Edmond

218

Resting-state activity in development and maintenance of normal brain function  

PubMed Central

One of the most intriguing recent discoveries concerning brain function is that intrinsic neuronal activity manifests as spontaneous fluctuations of the blood oxygen level–dependent (BOLD) functional MRI signal. These BOLD fluctuations exhibit temporal synchrony within widely distributed brain regions known as resting-state networks. Resting-state networks are present in the waking state, during sleep, and under general anesthesia, suggesting that spontaneous neuronal activity plays a fundamental role in brain function. Despite its ubiquitous presence, the physiological role of correlated, spontaneous neuronal activity remains poorly understood. One hypothesis is that this activity is critical for the development of synaptic connections and maintenance of synaptic homeostasis. We had a unique opportunity to test this hypothesis in a 5-y-old boy with severe epileptic encephalopathy. The child developed marked neurologic dysfunction in association with a seizure disorder, resulting in a 1-y period of behavioral regression and progressive loss of developmental milestones. His EEG showed a markedly abnormal pattern of high-amplitude, disorganized slow activity with frequent generalized and multifocal epileptiform discharges. Resting-state functional connectivity MRI showed reduced BOLD fluctuations and a pervasive lack of normal connectivity. The child underwent successful corpus callosotomy surgery for treatment of drop seizures. Postoperatively, the patient's behavior returned to baseline, and he resumed development of new skills. The waking EEG revealed a normal background, and functional connectivity MRI demonstrated restoration of functional connectivity architecture. These results provide evidence that intrinsic, coherent neuronal signaling may be essential to the development and maintenance of the brain's functional organization. PMID:21709227

Pizoli, Carolyn E.; Snyder, Abraham Z.; Shimony, Joshua S.; Limbrick, David D.; Schlaggar, Bradley L.; Smyth, Matthew D.

2011-01-01

219

Silicon Shrinkwrap Melts Smoothly Onto Cat Brain to Monitor Activity in Real Time  

E-print Network

Silicon Shrinkwrap Melts Smoothly Onto Cat Brain to Monitor Activity in Real Time By Jeremy Hsu Activity in Real Time Silk-Silicon Implantable Electronics Conform to Tissues, Then Melt Away Brain Scans, brains, cat brains, electrical activity, electrodes, implants, mesh, silicon, silk, surface electrodes

Rogers, John A.

220

Abnormal Brain Iron Metabolism in Irp2 Deficient Mice Is Associated with Mild Neurological and Behavioral Impairments  

PubMed Central

Iron Regulatory Protein 2 (Irp2, Ireb2) is a central regulator of cellular iron homeostasis in vertebrates. Two global knockout mouse models have been generated to explore the role of Irp2 in regulating iron metabolism. While both mouse models show that loss of Irp2 results in microcytic anemia and altered body iron distribution, discrepant results have drawn into question the role of Irp2 in regulating brain iron metabolism. One model shows that aged Irp2 deficient mice develop adult-onset progressive neurodegeneration that is associated with axonal degeneration and loss of Purkinje cells in the central nervous system. These mice show iron deposition in white matter tracts and oligodendrocyte soma throughout the brain. A contrasting model of global Irp2 deficiency shows no overt or pathological signs of neurodegeneration or brain iron accumulation, and display only mild motor coordination and balance deficits when challenged by specific tests. Explanations for conflicting findings in the severity of the clinical phenotype, brain iron accumulation and neuronal degeneration remain unclear. Here, we describe an additional mouse model of global Irp2 deficiency. Our aged Irp2?/? mice show marked iron deposition in white matter and in oligodendrocytes while iron content is significantly reduced in neurons. Ferritin and transferrin receptor 1 (TfR1, Tfrc), expression are increased and decreased, respectively, in the brain from Irp2?/? mice. These mice show impairments in locomotion, exploration, motor coordination/balance and nociception when assessed by neurological and behavioral tests, but lack overt signs of neurodegenerative disease. Ultrastructural studies of specific brain regions show no evidence of neurodegeneration. Our data suggest that Irp2 deficiency dysregulates brain iron metabolism causing cellular dysfunction that ultimately leads to mild neurological, behavioral and nociceptive impairments. PMID:24896637

Zumbrennen-Bullough, Kimberly B.; Becker, Lore; Garrett, Lillian; Hölter, Sabine M.; Calzada-Wack, Julia; Mossbrugger, Ilona; Quintanilla-Fend, Leticia; Racz, Ildiko; Rathkolb, Birgit; Klopstock, Thomas; Wurst, Wolfgang; Zimmer, Andreas; Wolf, Eckhard; Fuchs, Helmut; Gailus-Durner, Valerie; de Angelis, Martin Hrab?; Romney, Steven J.; Leibold, Elizabeth A.

2014-01-01

221

Spontaneous brain activity predicts learning ability of foreign sounds.  

PubMed

Can learning capacity of the human brain be predicted from initial spontaneous functional connectivity (FC) between brain areas involved in a task? We combined task-related functional magnetic resonance imaging (fMRI) and resting-state fMRI (rs-fMRI) before and after training with a Hindi dental-retroflex nonnative contrast. Previous fMRI results were replicated, demonstrating that this learning recruited the left insula/frontal operculum and the left superior parietal lobe, among other areas of the brain. Crucially, resting-state FC (rs-FC) between these two areas at pretraining predicted individual differences in learning outcomes after distributed (Experiment 1) and intensive training (Experiment 2). Furthermore, this rs-FC was reduced at posttraining, a change that may also account for learning. Finally, resting-state network analyses showed that the mechanism underlying this reduction of rs-FC was mainly a transfer in intrinsic activity of the left frontal operculum/anterior insula from the left frontoparietal network to the salience network. Thus, rs-FC may contribute to predict learning ability and to understand how learning modifies the functioning of the brain. The discovery of this correspondence between initial spontaneous brain activity in task-related areas and posttraining performance opens new avenues to find predictors of learning capacities in the brain using task-related fMRI and rs-fMRI combined. PMID:23719798

Ventura-Campos, Noelia; Sanjuán, Ana; González, Julio; Palomar-García, María-Ángeles; Rodríguez-Pujadas, Aina; Sebastián-Gallés, Núria; Deco, Gustavo; Ávila, César

2013-05-29

222

Impaired Brain Creatine Kinase Activity in Huntington's Disease  

PubMed Central

Background Huntington's disease (HD) is associated with impaired energy metabolism in the brain. Creatine kinase (CK) catalyzes ATP-dependent phosphorylation of creatine (Cr) into phosphocreatine (PCr), thereby serving as readily available high-capacity spatial and temporal ATP buffering. Objective: Substantial evidence supports a specific role of the Cr/PCr system in neurodegenerative diseases. In the brain, the Cr/PCr ATP-buffering system is established by a concerted operation of the brain-specific cytosolic enzyme BB-CK and ubiquitous mitochondrial uMt-CK. It is not yet established whether the activity of these CK isoenzymes is impaired in HD. Methods We measured PCr, Cr, ATP and ADP in brain extracts of 3 mouse models of HD – R6/2 mice, N171-82Q and HdhQ111 mice – and the activity of CK in cytosolic and mitochondrial brain fractions from the same mice. Results The PCr was significantly increased in mouse HD brain extracts as compared to nontransgenic littermates. We also found an approximately 27% decrease in CK activity in both cytosolic and mitochondrial fractions of R6/2 and N171-82Q mice, and an approximately 25% decrease in the mitochondria from HdhQ111 mice. Moreover, uMt-CK and BB-CK activities were approximately 63% lower in HD human brain samples as compared to nondiseased controls. Conclusion Our findings lend strong support to the role of impaired energy metabolism in HD, and point out the potential importance of impairment of the CK-catalyzed ATP-buffering system in the etiology of HD. PMID:21124007

Zhang, S.F.; Hennessey, T.; Yang, L.; Starkova, N.N.; Beal, M.F.; Starkov, A.A.

2011-01-01

223

Applications of electroencephalography to characterize brain activity: perspectives in stroke.  

PubMed

A wide array of neuroimaging technologies are now available that offer unprecedented opportunities to study the brain in health and disease. Each technology has associated strengths and weaknesses that need to be considered to maximize their utility, especially when used in combination. One imaging technology, electroencephalography (EEG), has been in use for more than 80 years, but as a result of recent technologic advancements EEG has received renewed interest as an inexpensive, noninvasive and versatile technique to evaluate neural activity in the brain. In part, this is due to new opportunities to combine EEG not only with other imaging modalities, but also with neurostimulation and robotics technologies. When used in combination, noninvasive brain stimulation and EEG can be used to study cause-and-effect relationships between interconnected brain regions providing new avenues to study brain function. Although many of these approaches are still in the developmental phase, there is substantial promise in their ability to deepen our understanding of brain function. The ability to capture the causal relationships between brain function and behavior in individuals with neurologic disorders or injury has important clinical implications for the development of novel biomarkers of recovery and response to therapeutic interventions. The goals of this paper are to provide an overview of the fundamental principles of EEG; discuss past, present, and future applications of EEG in the clinical management of stroke; and introduce the technique of combining EEG with a form of noninvasive brain stimulation, transcranial magnetic stimulation, as a powerful synergistic research paradigm to characterize brain function in both health and disease.Video Abstract available (see Supplemental Digital Content 1, http://links.lww.com/JNPT/A87) for more insights from the authors. PMID:25522236

Borich, Michael R; Brown, Katlyn E; Lakhani, Bimal; Boyd, Lara A

2015-01-01

224

Stress-induced asymmetric frontal brain activity and aggression risk.  

PubMed

Impersonal stressors, not only interpersonal provocation, can instigate aggression through an associative network linking negative emotions to behavioral activation (L. Berkowitz, 1990). Research has not examined the brain mechanisms that are engaged by different types of stress and serve to promote hostility and aggression. The present study examined whether stress exposure elicits more left than right frontal brain activity implicated in behavioral approach motivation and whether this lateralized brain activity predicts stress-induced aggression and hostile/aggressive tendencies. Results showed that (a) participants in the impersonal (assigned to stress by a computer) and interpersonal (assigned to stress by a provoking confederate) stress conditions both showed more left than right frontal electroencephalogram activity after condition assignment and stress exposure and (b) the 2 stress groups exhibited subsequent increases in aggression relative to the no-stress group. Importantly, left frontal asymmetry in response to stress exposure predicted increases in subsequent aggressive behavior, a finding that did not emerge in the no-stress condition. Thus, both the interpersonal and impersonal stressors impacted state changes in brain activity related to behavioral approach, suggesting that stress reactivity involving approach activation represents risk for behavioral dysregulation. PMID:19222320

Verona, Edelyn; Sadeh, Naomi; Curtin, John J

2009-02-01

225

Attention processing abnormalities in children with traumatic brain injury and attention-deficit\\/hyperactivity disorder: Differential impairment of component processes  

Microsoft Academic Search

Individuals with acquired and neurodevelopmental brain disorders often exhibit deficits in attention. Recent models of attention have conceptualized it as a multicomponent system. One influential model proposed by Mirsky et al. (1991) consists of factors that include focus, sustain, shift, and encode components. This model has been used to examine the structure of attention in a variety of clinical populations

Nicholas S. Thaler; Daniel N. Allen; Brandon S. Park; Janice C. McMurray; Joan Mayfield

2010-01-01

226

On a Mathematical Model of Brain Activities  

SciTech Connect

The procedure of recognition can be described as follows: There is a set of complex signals stored in the memory. Choosing one of these signals may be interpreted as generating a hypothesis concerning an 'expexted view of the world'. Then the brain compares a signal arising from our senses with the signal chosen from the memory leading to a change of the state of both signals. Furthermore, measurements of that procedure like EEG or MEG are based on the fact that recognition of signals causes a certain loss of excited neurons, i.e. the neurons change their state from 'excited' to 'nonexcited'. For that reason a statistical model of the recognition process should reflect both--the change of the signals and the loss of excited neurons. A first attempt to explain the process of recognition in terms of quantum statistics was given. In the present note it is not possible to present this approach in detail. In lieu we will sketch roughly a few of the basic ideas and structures of the proposed model of the recognition process (Section). Further, we introduce the basic spaces and justify the choice of spaces used in this approach. A more elaborate presentation including all proofs will be given in a series of some forthcoming papers. In this series also the procedures of creation of signals from the memory, amplification, accumulation and transformation of input signals, and measurements like EEG and MEG will be treated in detail.

Fichtner, K.-H. [Friedrich Schiller Unversity Jena, Institute of Applied Mathematics, E.-Abbe-Platz 2, 07743 Jena (Germany); Fichtner, L. [Friedrich Schiller Unversity Jena, Institute of Psychology, Am Steiger 3, 07743 Jena (Germany); Freudenberg, W. [Brandenb. Techn. University Cottbus, Dep. of Mathematics, PO box 10 13 44, 03013 Cottbus (Germany); Ohya, M. [Tokyo University of Science, Department of Information Science, Noda City, Chiba 278-8510 (Japan)

2007-12-03

227

Composition and On Demand Deployment of Distributed Brain Activity Analysis Application on Global Grids  

E-print Network

1 Composition and On Demand Deployment of Distributed Brain Activity Analysis Application on Global are brain science and high-energy physics. The analysis of brain activity data gathered from the MEG and analyze brain functions and requires access to large-scale computational resources. The potential platform

Abramson, David

228

Abnormal cortical lysosomal ?-hexosaminidase and ?-galactosidase activity at post-synaptic sites during Alzheimer's disease progression.  

PubMed

A critical role of endosomal-lysosomal system alteration in neurodegeneration is supported by several studies. Dysfunction of the lysosomal compartment is a common feature also in Alzheimer's disease. Altered expression of lysosomal glycohydrolases has been demonstrated not only in the brain and peripheral tissues of Alzheimer's disease patients, but also in presymptomatic subjects before degenerative phenomenon becomes evident. Moreover, the presence of glycohydrolases associated to the plasma membrane have been widely demonstrated and their alteration in pathological conditions has been documented. In particular, lipid microdomains-associated glycohydrolases can be functional to the maintenance of the proper glycosphingolipids pattern, especially at cell surface level, where they are crucial for the function of cell types such as neurons. In this study we investigated the localization of ?-hexosaminidase and ?-galactosidase glycohydrolases, both involved in step by step degradation of the GM1 to GM3 gangliosides, in lipid microdomains from the cortex of both an early and advanced TgCRND8 mouse model of Alzheimer's disease. Throughout immunoprecipitation experiments of purified cortical lipid microdomains, we demonstrated for the first time that ?-hexosaminidase and ?-galactosidase are associated with post-synaptic vesicles and that their activities are increased at both the early and the advanced stage of Alzheimer's disease. The early increase of lipid microdomain-associated ?-hexosaminidase and ?-galactosidase activities could have relevant implications for the pathophysiology of the disease since their possible pharmacological manipulation could shed light on new reliable targets and biological markers of Alzheimer's disease. PMID:25462158

Magini, Alessandro; Polchi, Alice; Tozzi, Alessandro; Tancini, Brunella; Tantucci, Michela; Urbanelli, Lorena; Borsello, Tiziana; Calabresi, Paolo; Emiliani, Carla

2015-01-01

229

Brain Activation during Sentence Comprehension among Good and Poor  

E-print Network

comprehension task among good and poor readers in the third (n 5 32) and fifth (n 5 35) grades. Reading ability struggling readers during a higher-level reading comprehension task (Seki et al. 2001 report a smallBrain Activation during Sentence Comprehension among Good and Poor Readers Ann Meyler1 , Timothy A

230

The Design of Integrated Circuits to Observe Brain Activity  

Microsoft Academic Search

The ability to monitor the simultaneous electrical activity of multiple neurons in the brain enables a wide range of scientific and clinical endeavors. Recent efforts to merge miniature multielectrode neural recording arrays with integrated electronics have revealed significant circuit design challenges. Weak neural signals must be amplified and filtered using low-noise circuits placed close to the electrodes themselves, but power

Reid R. Harrison

2008-01-01

231

Working Memory Training: Improving Intelligence--Changing Brain Activity  

ERIC Educational Resources Information Center

The main objectives of the study were: to investigate whether training on working memory (WM) could improve fluid intelligence, and to investigate the effects WM training had on neuroelectric (electroencephalography--EEG) and hemodynamic (near-infrared spectroscopy--NIRS) patterns of brain activity. In a parallel group experimental design,…

Jausovec, Norbert; Jausovec, Ksenija

2012-01-01

232

Chondroitinase enhances cortical map plasticity and increases functionally active sprouting axons after brain injury.  

PubMed

The beneficial effect of interventions with chondroitinase ABC enzyme to reduce axon growth-inhibitory chondroitin sulphate side chains after central nervous system injuries has been mainly attributed to enhanced axonal sprouting. After traumatic brain injury (TBI), it is unknown whether newly sprouting axons that occur as a result of interventional strategies are able to functionally contribute to existing circuitry, and it is uncertain whether maladaptive sprouting occurs to increase the well-known risk for seizure activity after TBI. Here, we show that after a controlled cortical impact injury in rats, chondroitinase infusion into injured cortex at 30?min and 3 days reduced c-Fos? cell staining resulting from the injury alone at 1 week postinjury, indicating that at baseline, abnormal spontaneous activity is likely to be reduced, not increased, with this type of intervention. c-Fos? cell staining elicited by neural activity from stimulation of the affected forelimb 1 week after injury was significantly enhanced by chondroitinase, indicating a widespread effect on cortical map plasticity. Underlying this map plasticity was a larger contribution of neuronal, rather than glial cells and an absence of c-Fos? cells surrounded by perineuronal nets that were normally present in stimulated naïve rats. After injury, chondroitin sulfate proteoglycan digestion produced the expected increase in growth-associated protein 43-positive axons and perikarya, of which a significantly greater number were double labeled for c-Fos after intervention with chondroitinase, compared to vehicle. These data indicate that chondroitinase produces significant gains in cortical map plasticity after TBI, and that either axonal sprouting and/or changes in perineuronal nets may underlie this effect. Chondroitinase dampens, rather than increases nonspecific c-Fos activity after brain injury, and induction of axonal sprouting is not maladaptive because greater numbers are functionally active and provide a significant contribution to forelimb circuitry after brain injury. PMID:23517225

Harris, Neil G; Nogueira, Marcia S M; Verley, Derek R; Sutton, Richard L

2013-07-15

233

Chondroitinase Enhances Cortical Map Plasticity and Increases Functionally Active Sprouting Axons after Brain Injury  

PubMed Central

Abstract The beneficial effect of interventions with chondroitinase ABC enzyme to reduce axon growth-inhibitory chondroitin sulphate side chains after central nervous system injuries has been mainly attributed to enhanced axonal sprouting. After traumatic brain injury (TBI), it is unknown whether newly sprouting axons that occur as a result of interventional strategies are able to functionally contribute to existing circuitry, and it is uncertain whether maladaptive sprouting occurs to increase the well-known risk for seizure activity after TBI. Here, we show that after a controlled cortical impact injury in rats, chondroitinase infusion into injured cortex at 30?min and 3 days reduced c-Fos+ cell staining resulting from the injury alone at 1 week postinjury, indicating that at baseline, abnormal spontaneous activity is likely to be reduced, not increased, with this type of intervention. c-Fos+ cell staining elicited by neural activity from stimulation of the affected forelimb 1 week after injury was significantly enhanced by chondroitinase, indicating a widespread effect on cortical map plasticity. Underlying this map plasticity was a larger contribution of neuronal, rather than glial cells and an absence of c-Fos+ cells surrounded by perineuronal nets that were normally present in stimulated naïve rats. After injury, chondroitin sulfate proteoglycan digestion produced the expected increase in growth-associated protein 43–positive axons and perikarya, of which a significantly greater number were double labeled for c-Fos after intervention with chondroitinase, compared to vehicle. These data indicate that chondroitinase produces significant gains in cortical map plasticity after TBI, and that either axonal sprouting and/or changes in perineuronal nets may underlie this effect. Chondroitinase dampens, rather than increases nonspecific c-Fos activity after brain injury, and induction of axonal sprouting is not maladaptive because greater numbers are functionally active and provide a significant contribution to forelimb circuitry after brain injury. PMID:23517225

Nogueira, Marcia S.M.; Verley, Derek R.; Sutton, Richard L.

2013-01-01

234

Involvement of oxidative stress-induced abnormalities in ceramide and cholesterol metabolism in brain aging and Alzheimer's disease  

NASA Astrophysics Data System (ADS)

Alzheimer's disease (AD) is an age-related disorder characterized by deposition of amyloid -peptide (A) and degeneration of neurons in brain regions such as the hippocampus, resulting in progressive cognitive dysfunction. The pathogenesis of AD is tightly linked to A deposition and oxidative stress, but it remains unclear as to how these factors result in neuronal dysfunction and death. We report alterations in sphingolipid and cholesterol metabolism during normal brain aging and in the brains of AD patients that result in accumulation of long-chain ceramides and cholesterol. Membrane-associated oxidative stress occurs in association with the lipid alterations, and exposure of hippocampal neurons to A induces membrane oxidative stress and the accumulation of ceramide species and cholesterol. Treatment of neurons with -tocopherol or an inhibitor of sphingomyelin synthesis prevents accumulation of ceramides and cholesterol and protects them against death induced by A. Our findings suggest a sequence of events in the pathogenesis of AD in which A induces membrane-associated oxidative stress, resulting in perturbed ceramide and cholesterol metabolism which, in turn, triggers a neurodegenerative cascade that leads to clinical disease. amyloid | apoptosis | hippocampus | lipid peroxidation | sphingomyelin

Cutler, Roy G.; Kelly, Jeremiah; Storie, Kristin; Pedersen, Ward A.; Tammara, Anita; Hatanpaa, Kimmo; Troncoso, Juan C.; Mattson, Mark P.

2004-02-01

235

Neurological Abnormalities in Full-Term Asphyxiated Newborns and Salivary S100B Testing: The “Cooperative Multitask against Brain Injury of Neonates” (CoMBINe) International Study  

PubMed Central

Background Perinatal asphyxia (PA) is a leading cause of mortality and morbidity in newborns: its prognosis depends both on the severity of the asphyxia and on the immediate resuscitation to restore oxygen supply and blood circulation. Therefore, we investigated whether measurement of S100B, a consolidated marker of brain injury, in salivary fluid of PA newborns may constitute a useful tool for the early detection of asphyxia-related brain injury. Methods We conducted a cross-sectional study in 292 full-term newborns admitted to our NICUs, of whom 48 suffered PA and 244 healthy controls admitted at our NICUs. Saliva S100B levels measurement longitudinally after birth; routine laboratory variables, neurological patterns, cerebral ultrasound and, magnetic resonance imaging were performed. The primary end-point was the presence of neurological abnormalities at 12-months after birth. Results S100B salivary levels were significantly (P<0.001) higher in newborns with PA than in normal infants. When asphyxiated infants were subdivided according to a good (Group A; n = 15) or poor (Group B; n = 33) neurological outcome at 12-months, S100B was significantly higher at all monitoring time-points in Group B than in Group A or controls (P<0.001, for all). A cut-off >3.25 MoM S100B achieved a sensitivity of 100% (CI5-95%: 89.3%-100%) and a specificity of 100% (CI5-95%: 98.6%-100%) as a single marker for predicting the occurrence of abnormal neurological outcome (area under the ROC curve: 1.000; CI5-95%: 0.987-1.0). Conclusions S100B protein measurement in saliva, soon after birth, is a useful tool to identify which asphyxiated infants are at risk of neurological sequelae. PMID:25569796

Gazzolo, Diego; Pluchinotta, Francesca; Bashir, Moataza; Aboulgar, Hanna; Said, Hala Mufeed; Iman, Iskander; Ivani, Giorgio; Conio, Alessandra; Tina, Lucia Gabriella; Nigro, Francesco; Li Volti, Giovanni; Galvano, Fabio; Michetti, Fabrizio; Di Iorio, Romolo; Marinoni, Emanuela; Zimmermann, Luc J.; Gavilanes, Antonio D. W.; Vles, Hans J. S.; Kornacka, Maria; Gruszfeld, Darek; Frulio, Rosanna; Sacchi, Renata; Ciotti, Sabina; Risso, Francesco M.; Sannia, Andrea; Florio, Pasquale

2015-01-01

236

Brain Electrical Activity Changes and Cognitive Development.  

ERIC Educational Resources Information Center

This study investigated the relationship of cognitive developmental changes to physiological and anatomical changes by measuring both types of data within the same subjects. Cortical electrical activity was measured in 24 males between 10 and 12 years of age. Event-related potentials (ERPs) were recorded from midline scalp electrodes during a…

Hartley, Deborah; Thomas, David G.

237

Active Lessons for Active Brains: Teaching Boys and Other Experiential Learners, Grades 3-10  

ERIC Educational Resources Information Center

If you're tired of repeating yourself to students who aren't listening, try a little less talk and a lot more action. The authors follow the best-selling "Teaching the Male Brain and Teaching the Female Brain" with this ready-to-use collection of mathematics, language arts, science, and classroom management strategies. Designed for active,…

James, Abigail Norfleet; Allison, Sandra Boyd; McKenzie, Caitlin Zimmerman

2011-01-01

238

A multimodal assessment of melanin and melanocyte activity in abnormally pigmented hypertrophic scar.  

PubMed

Using a validated swine model of human scar formation, hyperpigmented and hypopigmented scar samples were examined for their histological and optical properties to help elucidate the mechanisms and characteristics of dyspigmentation. Full-thickness wounds were created on the flanks of red Duroc pigs and allowed to heal. Biopsies from areas of hyperpigmentation, hypopigmentation, and uninjured tissue were fixed and embedded for histological examination using Azure B and primary antibodies to S100B, HMB45, and ?-melanocyte-stimulating hormone (?-MSH). Spatial frequency domain imaging (SFDI) was then used to examine the optical properties of scars. Hyperpigmentation was first noticeable in healing wounds around weeks 2 to 3, gradually becoming darker. There was no significant difference in S100B staining for the presence of melanocytes between hyperpigmented and hypopigmented scar samples. Azure B staining of melanin was significantly greater in histological sections from hyperpigmented areas than in sections from both uninjured skin and hypopigmented scar (P < .0001). There was significantly greater staining for ?-MSH in hyperpigmented samples compared with hypopigmented samples (P = .0121), and HMB45 staining was positive for melanocytes in hyperpigmented scar. SFDI at a wavelength of 632 nm resulted in an absorption coefficient map correlating with visibly hyperpigmented areas of scars. In a red Duroc model of hypertrophic scar formation, melanocyte number is similar in hyperpigmented and hypopigmented tissues. Hyperpigmented tissues, however, show a greater amount of melanin and ?-MSH, along with immunohistochemical evidence of stimulated melanocytes. These observations encourage further investigation of melanocyte stimulation and the inflammatory environment within a wound that may influence melanocyte activity. Additionally, SFDI can be used to identify areas of melanin content in mature, pigmented scars, which may lead to its usefulness in wounds at earlier time points before markedly apparent pigmentation abnormalities. PMID:25162947

Travis, Taryn E; Ghassemi, Pejhman; Ramella-Roman, Jessica C; Prindeze, Nicholas J; Paul, Dereck W; Moffatt, Lauren T; Jordan, Marion H; Shupp, Jeffrey W

2015-01-01

239

Diffusion-Weighted Magnetic Resonance Imaging Reversal by Gene Knockdown of Matrix Metalloproteinase-9 Activities in Live Animal Brains  

PubMed Central

The involvement of matrix metalloproteinase-9 (MMP-9) activities in the development of abnormal water diffusion in the brain after cardiac arrest is not fully understood. We used magnetic resonance imaging to determine the correlation between MMP-9 activity and the mechanism of abnormal water diffusion after global cerebral ischemia (GCI)-induced brain damage in C57black6 mice. We induced GCI in mice by occluding both carotid arteries for 60 min, then allowing reperfusion. We labeled a short DNA that targets mmp-9 mRNA activity [phosphorothioate-modified oligodeoxynucleotide (sODN)-mmp9] or a control probe without intracellular target (sODN-Ran) with iron-based MR contrast agent [superparamagnetic iron oxide nanoparticle (SPION)-mmp9 or SPION-Ran] or fluorescein isothiocyanate (FITC)-sODN-mmp9 or FITC-sODN-Ran; we then delivered these probes by intracerebroventricular infusion or intraperitoneal injection with in 3 h of reperfusion. At low dose (120 pmol/kg) the SPION-mmp9 probe was retained at significant levels in the striatum and cortex of living brains 10 h after GCI. Probe retention was validated by similar elevation of mmp-9 mRNA and antigens in postmortem samples taken from regions that exhibited GCI-induced hyperintensity in diffusion-weighted imaging, and a significant reduction in apparent diffusion coefficient (rADC, p = 0.0006, n = 12). At a higher dose (120 nmol/kg), the FITC-sODN-mmp9 probe revealed significant knockdown of MMP-9 activity, per zymography, and a reversal of striatal rADC (p = 0.004, n = 6). These observations were not duplicated in the control group. We conclude that expression of mmp-9 mRNA is associated with abnormal ADC after GCI. PMID:19295156

Liu, Christina H.; You, Zerong; Liu, Charng-Ming; Kim, Young R.; Whalen, Michael J.; Rosen, Bruce R.; Liu, Philip K.

2009-01-01

240

Breastfeeding, Brain Activation to Own Infant Cry, and Maternal Sensitivity  

PubMed Central

Background Research points to the importance of breastfeeding for promoting close mother-infant contact and social-emotional development. Recent functional magnetic resonance imaging (fMRI) studies have identified brain regions related to maternal behaviors. However, little research has addressed the neurobiological mechanisms underlying the relationship between breastfeeding and maternal behavior in human mothers. We investigated the associations between breastfeeding, maternal brain response to own infant stimuli, and maternal sensitivity in the early postpartum. Methods Seventeen biological mothers of healthy infants participated in two matched groups according to feeding method – exclusive breastfeeding and exclusive formula-feeding at 2-4 weeks postpartum. fMRI scanning was conducted in the first postpartum month to examine maternal brain activation in response to her own baby's cry versus control baby-cry. Dyadic interactions between mothers and infants at 3-4 months postpartum were videotaped in the home and blindly coded for maternal sensitivity. Results In the first postpartum month, breastfeeding mothers showed greater activations in the superior frontal gyrus, insula, precuneus, striatum, and amygdala while listening to their own baby-cry as compared to formula-feeding mothers. For both breastfeeding and formula-feeding mothers, greater activations in the right superior frontal gyrus and amygdala were associated with higher maternal sensitivity at 3-4 months postpartum. Conclusions Results suggest links between breastfeeding and greater response to infant cues in brain regions implicated in maternal-infant bonding and empathy during the early postpartum. Such brain activations may facilitate greater maternal sensitivity as infants enter their social world. PMID:21501165

Kim, Pilyoung; Feldman, Ruth; Mayes, Linda C.; Eicher, Virginia; Thompson, Nancy; Leckman, James F.; Swain, James E.

2011-01-01

241

Water diffusion in brain cortex closely tracks underlying neuronal activity  

PubMed Central

Neuronal activity results in a local increase in blood flow. This concept serves as the basis for functional MRI. Still, this approach remains indirect and may fail in situations interfering with the neurovascular coupling mechanisms (drugs, anesthesia). Here we establish that water molecular diffusion is directly modulated by underlying neuronal activity using a rat forepaw stimulation model under different conditions of neuronal stimulation and neurovascular coupling. Under nitroprusside infusion, a neurovascular-coupling inhibitor, the diffusion response and local field potentials were maintained, whereas the hemodynamic response was abolished. As diffusion MRI reflects interactions of water molecules with obstacles (e.g., cell membranes), the observed changes point to a dynamic modulation of the neural tissue structure upon activation, which remains to be investigated. These findings represent a significant shift in concept from the current electrochemical and neurovascular coupling principles used for brain imaging, and open unique avenues to investigate mechanisms underlying brain function. PMID:23801756

Tsurugizawa, Tomokazu; Ciobanu, Luisa; Le Bihan, Denis

2013-01-01

242

Whole-brain gray matter volume abnormalities in patients with generalized anxiety disorder: voxel-based morphometry.  

PubMed

Patients with generalized anxiety disorder (GAD) experience psychological distress because of excessive and uncontrollable anxiety in everyday life. Only a few morphological studies have so far focused on specific brain regions of interest as well as the gray matter volume changes in GAD patients. This study evaluated gray matter volume alterations in whole-brain areas between GAD patients and healthy controls, and sex differences between the specific brain areas with significant volume changes in GAD patients using voxel-based morphometry. Twenty-two patients with GAD (13 men and nine women), who were diagnosed using the DSM-IV-TR, and 22 age-matched healthy controls (13 men and nine women) participated in this study. The high-resolution MRI data were processed using voxel-based morphometry analysis on the basis of diffeomorphic anatomical registration through an exponentiated Lie algebra algorithm in Statistical Parametric Mapping 8. There was no significant difference in the total intracranial volume between GAD patients and controls, but a significant difference was observed between sexes (P<0.05). Patients with GAD showed significant volume reductions in the hippocampus, midbrain, thalamus, insula, and superior temporal gyrus compared with the controls. As for the sex comparison, female patients showed a significant increase in the volume of the dorsolateral prefrontal cortex relative to male patients. Also, the volume of the dorsolateral prefrontal cortex in female patients was correlated positively with the Hamilton Anxiety Rating Scale score (?=0.68, P=0.04). The specific morphological variations in patient with GAD will be helpful to understand the neural mechanism associated with a symptom of GAD. Furthermore, the findings would be valuable for the diagnostic accuracy of GAD using morphometric MRI analysis. PMID:24476839

Moon, Chung-Man; Kim, Gwang-Won; Jeong, Gwang-Woo

2014-02-12

243

Alteration of Interictal Brain Activity in Patients with Temporal Lobe Epilepsy in the Left Dominant Hemisphere: A Resting-State MEG Study  

PubMed Central

Resting MEG activities were compared between patients with left temporal lobe epilepsy (LTLE) and normal controls. Using SAMg2, the activities of MEG data were reconstructed and normalized. Significantly elevated SAMg2 signals were found in LTLE patients in the left temporal lobe and medial structures. Marked decreases of SAMg2 signals were found in the wide extratemporal lobe regions, such as the bilateral visual cortex. The study also demonstrated a positive correlation between the seizure frequency and brain activities of the abnormal regions after the multiple linear regression analysis. These results suggested that the aberrant brain activities not only were related to the epileptogenic zones, but also existed in other extratemporal regions in patients with LTLE. The activities of the aberrant regions could be further damaged with the increase of the seizure frequency. Our findings indicated that LTLE could be a multifocal disease, including complex epileptic networks and brain dysfunction networks. PMID:25136558

Zhu, Haitao; Zhu, Jinlong; Zhao, Tiezhu; Wu, Yong; Liu, Hongyi; Wu, Ting; Yang, Lu; Zou, Yuanjie; Zhang, Rui; Zheng, Gang

2014-01-01

244

Brain activation during anticipation of sound sequences.  

PubMed

Music consists of sound sequences that require integration over time. As we become familiar with music, associations between notes, melodies, and entire symphonic movements become stronger and more complex. These associations can become so tight that, for example, hearing the end of one album track can elicit a robust image of the upcoming track while anticipating it in total silence. Here, we study this predictive "anticipatory imagery" at various stages throughout learning and investigate activity changes in corresponding neural structures using functional magnetic resonance imaging. Anticipatory imagery (in silence) for highly familiar naturalistic music was accompanied by pronounced activity in rostral prefrontal cortex (PFC) and premotor areas. Examining changes in the neural bases of anticipatory imagery during two stages of learning conditional associations between simple melodies, however, demonstrates the importance of fronto-striatal connections, consistent with a role of the basal ganglia in "training" frontal cortex (Pasupathy and Miller, 2005). Another striking change in neural resources during learning was a shift between caudal PFC earlier to rostral PFC later in learning. Our findings regarding musical anticipation and sound sequence learning are highly compatible with studies of motor sequence learning, suggesting common predictive mechanisms in both domains. PMID:19244522

Leaver, Amber M; Van Lare, Jennifer; Zielinski, Brandon; Halpern, Andrea R; Rauschecker, Josef P

2009-02-25

245

Decomposition of spontaneous brain activity into distinct fMRI co-activation patterns  

PubMed Central

Recent fMRI studies have shown that analysis of the human brain's spontaneous activity may provide a powerful approach to reveal its functional organization. Dedicated methods have been proposed to investigate co-variation of signals from different brain regions, with the goal of revealing neuronal networks (NNs) that may serve specialized functions. However, these analysis methods generally do not take into account a potential non-stationary (variable) interaction between brain regions, and as a result have limited effectiveness. To address this, we propose a novel analysis method that uses clustering analysis to sort and selectively average fMRI activity time frames to produce a set of co-activation patterns. Compared to the established networks extracted with conventional analysis methods, these co-activation patterns demonstrate novel network features with apparent relevance to the brain's functional organization. PMID:24550788

Liu, Xiao; Chang, Catie; Duyn, Jeff H.

2013-01-01

246

Fast transient networks in spontaneous human brain activity.  

PubMed

To provide an effective substrate for cognitive processes, functional brain networks should be able to reorganize and coordinate on a sub-second temporal scale. We used magnetoencephalography recordings of spontaneous activity to characterize whole-brain functional connectivity dynamics at high temporal resolution. Using a novel approach that identifies the points in time at which unique patterns of activity recur, we reveal transient (100-200 ms) brain states with spatial topographies similar to those of well-known resting state networks. By assessing temporal changes in the occurrence of these states, we demonstrate that within-network functional connectivity is underpinned by coordinated neuronal dynamics that fluctuate much more rapidly than has previously been shown. We further evaluate cross-network interactions, and show that anticorrelation between the default mode network and parietal regions of the dorsal attention network is consistent with an inability of the system to transition directly between two transient brain states. DOI: http://dx.doi.org/10.7554/eLife.01867.001. PMID:24668169

Baker, Adam P; Brookes, Matthew J; Rezek, Iead A; Smith, Stephen M; Behrens, Timothy; Probert Smith, Penny J; Woolrich, Mark

2014-01-01

247

Contributions of glycogen to astrocytic energetics during brain activation.  

PubMed

Glycogen is the major store of glucose in brain and is mainly in astrocytes. Brain glycogen levels in unstimulated, carefully-handled rats are 10-12 ?mol/g, and assuming that astrocytes account for half the brain mass, astrocytic glycogen content is twice as high. Glycogen turnover is slow under basal conditions, but it is mobilized during activation. There is no net increase in incorporation of label from glucose during activation, whereas label release from pre-labeled glycogen exceeds net glycogen consumption, which increases during stronger stimuli. Because glycogen level is restored by non-oxidative metabolism, astrocytes can influence the global ratio of oxygen to glucose utilization. Compensatory increases in utilization of blood glucose during inhibition of glycogen phosphorylase are large and approximate glycogenolysis rates during sensory stimulation. In contrast, glycogenolysis rates during hypoglycemia are low due to continued glucose delivery and oxidation of endogenous substrates; rates that preserve neuronal function in the absence of glucose are also low, probably due to metabolite oxidation. Modeling studies predict that glycogenolysis maintains a high level of glucose-6-phosphate in astrocytes to maintain feedback inhibition of hexokinase, thereby diverting glucose for use by neurons. The fate of glycogen carbon in vivo is not known, but lactate efflux from brain best accounts for the major metabolic characteristics during activation of living brain. Substantial shuttling coupled with oxidation of glycogen-derived lactate is inconsistent with available evidence. Glycogen has important roles in astrocytic energetics, including glucose sparing, control of extracellular K(+) level, oxidative stress management, and memory consolidation; it is a multi-functional compound. PMID:24515302

Dienel, Gerald A; Cruz, Nancy F

2015-02-01

248

Worry tendencies predict brain activation during aversive imagery.  

PubMed

Because of its abstract nature, worrying might function as an avoidance response in order to cognitively disengage from fearful imagery. The present functional magnetic resonance imaging study investigated neural correlates of aversive imagery and their association with worry tendencies, as measured by the Penn State Worry Questionnaire (PSWQ). Nineteen healthy women first viewed, and subsequently imagined pictures from two categories, 'threat' and 'happiness'. Worry tendencies were negatively correlated with brain activation in the anterior cingulate cortex, the prefrontal cortex (dorsolateral, dorsomedial, ventrolateral), the parietal cortex and the insula. These negative correlations between PSWQ scores and localized brain activation were specific for aversive imagery. Moreover, activation in the above mentioned regions was positively associated with the experienced vividness of both pleasant and unpleasant mental pictures. As the identified brain regions are involved in emotion regulation, vivid imagery and memory retrieval, a lowered activity in high PSWQ scorers might be associated with cognitive disengagement from aversive imagery as well as insufficient refresh rates of mental pictures. Our preliminary findings encourage future imagery studies on generalized anxiety disorder patients, as one of the main symptoms of this disorder is excessive worrying. PMID:19545612

Schienle, Anne; Schäfer, Axel; Pignanelli, Roman; Vaitl, Dieter

2009-09-25

249

Anomalous Light Phenomena vs. Bioelectric Brain Activity  

NASA Astrophysics Data System (ADS)

We present a research proposal concerning the instrumented investigation of anomalous light phenomena that are apparently correlated with particular mind states, such as prayer, meditation or psi. Previous research by these authors demonstrate that such light phenomena can be monitored and measured quite efficiently in areas of the world where they are reported in a recurrent way. Instruments such as optical equipment for photography and spectroscopy, VLF spectrometers, magnetometers, radar and IR viewers were deployed and used massively in several areas of the world. Results allowed us to develop physical models concerning the structural and time-variable behaviour of light phenomena, and their kinematics. Recent insights and witnesses have suggested to us that a sort of "synchronous connection" seems to exist between plasma-like phenomena and particular mind states of experiencers who seem to trigger a light manifestation which is very similar to the one previously investigated. The main goal of these authors is now aimed at the search for a concrete "entanglement-like effect" between the experiencer's mind and the light phenomena, in such a way that both aspects are intended to be monitored and measured simultaneously using appropriate instrumentation. The goal of this research project is twofold: a) to verify quantitatively the existence of one very particular kind of mind-matter interaction and to study in real time its physical and biophysical manifestations; b) to repeat the same kind of experiment using the same test-subject in different locations and under various conditions of geomagnetic activity.

Teodorani, M.; Nobili, G.

250

[Features of brain oscillatory activity and cardiac defense in treatment arterial hypertensives].  

PubMed

Stress reactivity of the motivational system of defense can be assessed with the aid the cardiac defense response (CDR) - the reaction of the cardiovascular system to unexpected aversive unconditioned stimulus. The main objective of the study was revealing putative contribution of oscillatory systems of the brain into central pathogenic mechanisms of enhanced blood pressure (BP) stress-reactivity in naive patients with arterial hypertension (AH) of the 1st-2nd degrees (n = 17) and healthy control (n = 19) subjects. Using dynamic registration "beat-by-beat" arterial pressure, and oscillatory activity related EEG (64 channels) is estimated using the event-related synchronization/desynchronization (ERD/ERS). Along with abnormally high blood pressure in patients with hypertension background set significantly lower concentrations of serotonin blood platelets and increased tonic activation of the left hemisphere, reflected in the asymmetric reduction of delta- (2-4 Hz) and theta-1 (4-6 Hz) power in the central and parietal cortex in the hemisphere CDR of the patients are characterized by hyperactivity both short- and long-latency components of blood pressure. According to the dynamic analysis of the concomitant EEG, long-latency BP components may be accounted by, among other mechanisms, weakening of the descending ("top-down") inhibitory control, hypothetically implemented with the high-frequency EEG alpha (10-12 Hz) oscillations from the medial central-parietal cortex of both hemispheres of the brain. PMID:25464727

2014-01-01

251

[Features of brain oscillatory activity and cardiac defense in treatment arterial hypertensives].  

PubMed

Stress reactivity of the motivational system of defense can be assessed with the aid the cardiac defense response (CDR) - the reaction of the cardiovascular system to unexpected aversive unconditioned stimulus. The main objective of the study was revealing putative contribution of oscillatory systems of the brain into central pathogenic mechanisms of enhanced blood pressure (BP) stress-reactivity in naive patients with arterial hypertension (AH) of the 1st-2nd degrees (n = 17) and healthy control (n = 19) subjects. Using dynamic registration "beat-by-beat" arterial pressure, and oscillatory activity related EEG (64 channels) is estimated using the event-related synchronization/desynchronization (ERD/ERS). Along with abnormally high blood pressure in patients with hypertension background set significantly lower concentrations of serotonin blood platelets and increased tonic activation of the left hemisphere, reflected in the asymmetric reduction of delta- (2-4 Hz) and theta-1 (4-6 Hz) power in the central and parietal cortex in the hemisphere CDR of the patients are characterized by hyperactivity both short- and long-latency components of blood pressure. According to the dynamic analysis of the concomitant EEG, long-latency BP components may be accounted by, among other mechanisms, weakening of the descending ("top-down") inhibitory control, hypothetically implemented with the high-frequency EEG alpha (10-12 Hz) oscillations from the medial central-parietal cortex of both hemispheres of the brain. PMID:25508358

2014-01-01

252

Multichannel EEG Brain Activity Pattern Analysis in Time-Frequency Domain with Nonnegative Matrix  

E-print Network

(NMF) post-processing section in brain computer interface (BCI) training paradigm is presented: EEG, time-frequency signal analysis, brain computer interface, empirical mode decomposition electrical brain activity to control devices or computers in form of brain computer interfaces (BCI

Cichocki, Andrzej

253

Quantitative Brain Electrical Activity in the Initial Screening of Mild Traumatic Brain Injuries  

PubMed Central

Introduction: The incidence of emergency department (ED) visits for Traumatic Brain Injury (TBI) in the United States exceeds 1,000,000 cases/year with the vast majority classified as mild (mTBI). Using existing computed tomography (CT) decision rules for selecting patients to be referred for CT, such as the New Orleans Criteria (NOC), approximately 70% of those scanned are found to have a negative CT. This study investigates the use of quantified brain electrical activity to assess its possible role in the initial screening of ED mTBI patients as compared to NOC. Methods: We studied 119 patients who reported to the ED with mTBI and received a CT. Using a hand-held electroencephalogram (EEG) acquisition device, we collected data from frontal leads to determine the likelihood of a positive CT. The brain electrical activity was processed off-line to generate an index (TBI-Index, biomarker). This index was previously derived using an independent population, and the value found to be sensitive for significant brain dysfunction in TBI patients. We compared this performance of the TBI-Index to the NOC for accuracy in prediction of positive CT findings. Results: Both the brain electrical activity TBI-Index and the NOC had sensitivities, at 94.7% and 92.1% respectively. The specificity of the TBI-Index was more than twice that of NOC, 49.4% and 23.5% respectively. The positive predictive value, negative predictive value and the positive likelihood ratio were better with the TBI-Index. When either the TBI-Index or the NOC are positive (combining both indices) the sensitivity to detect a positive CT increases to 97%. Conclusion: The hand-held EEG device with a limited frontal montage is applicable to the ED environment and its performance was superior to that obtained using the New Orleans criteria. This study suggests a possible role for an index of brain function based on EEG to aid in the acute assessment of mTBI patients. PMID:23359586

O’Neil, Brian; Prichep, Leslie S.; Naunheim, Roseanne; Chabot, Robert

2012-01-01

254

Understanding Brain Tumors  

MedlinePLUS

... to Know About Brain Tumors . What is a Brain Tumor? A brain tumor is an abnormal growth? ... Tumors” from Frankly Speaking Frankly Speaking About Cancer: Brain Tumors Download the full book Questions to ask ...

255

Human brain activity with near-infrared spectroscopy  

NASA Astrophysics Data System (ADS)

Human brain activity was studied with a real time functional Near-InfraRed Imager (fNIRI). The imager has 16 measurement channels and covers 4 cm by 9 cm detection area. Brain activities in occipital, motor and prefrontal area were studied with the fNIRI. In prefrontal stimulation, language cognition, analogies, forming memory for new associations, emotional thinking, and mental arithmetic were carried out. Experimental results measured with fNIRI are demonstrated in this paper. It was shown that fNIRI technique is able to reveal the occipital activity during visual stimulation, and co-register well with results of fMRI in the motor cortex activity during finger tapping. In the studies of the effects of left prefrontal lobe on forming memory for new associations, it is shown that left prefrontal lobe activated more under deep conditions than that under shallow encoding, especially the dorsal part. In the studies of emotional thinking, it was shown that the responses were different between positive- negative emotional thinking and negative-positive emotional thinking. In mental arithmetic studies, higher activation was found in the first task than in the second, regardless of the difficulty, and higher activation was measured in subtraction of 17 than in subtraction of 3.

Luo, Qingming; Chance, Britton

1999-09-01

256

Error-related brain activity in obsessive–compulsive undergraduates  

Microsoft Academic Search

Error-related negativity (ERN\\/Ne) is a component of the event-related brain potential (ERP) associated with monitoring action and detecting errors. It is a sharp negative deflection that generally occurs from 50 to 150 ms following response execution and has been associated with activity involving the anterior cingulate cortex (ACC). An enhanced ERN has recently been observed in patients with obsessive–compulsive disorder

Greg Hajcak; Robert F. Simons

2002-01-01

257

Identification of abnormal motor cortex activation patterns in children with cerebral palsy by functional near-infrared spectroscopy  

NASA Astrophysics Data System (ADS)

We demonstrate the utility of functional near-infrared spectroscopy (fNIRS) as a tool for physicians to study cortical plasticity in children with cerebral palsy (CP). Motor cortex activation patterns were studied in five healthy children and five children with CP (8.4+/-2.3 years old in both groups) performing a finger-tapping protocol. Spatial (distance from center and area difference) and temporal (duration and time-to-peak) image metrics are proposed as potential biomarkers for differentiating abnormal cortical activation in children with CP from healthy pediatric controls. In addition, a similarity image-analysis concept is presented that unveils areas that have similar activation patterns as that of the maximum activation area, but are not discernible by visual inspection of standard activation images. Metrics derived from the images presenting areas of similarity are shown to be sensitive identifiers of abnormal activation patterns in children with CP. Importantly, the proposed similarity concept and related metrics may be applicable to other studies for the identification of cortical activation patterns by fNIRS.

Khan, Bilal; Tian, Fenghua; Behbehani, Khosrow; Romero, Mario I.; Delgado, Mauricio R.; Clegg, Nancy J.; Smith, Linsley; Reid, Dahlia; Liu, Hanli; Alexandrakis, George

2010-05-01

258

Tracking of EEG activity using motion estimation to understand brain wiring.  

PubMed

The fundamental step in brain research deals with recording electroencephalogram (EEG) signals and then investigating the recorded signals quantitatively. Topographic EEG (visual spatial representation of EEG signal) is commonly referred to as brain topomaps or brain EEG maps. In this chapter, full search full search block motion estimation algorithm has been employed to track the brain activity in brain topomaps to understand the mechanism of brain wiring. The behavior of EEG topomaps is examined throughout a particular brain activation with respect to time. Motion vectors are used to track the brain activation over the scalp during the activation period. Using motion estimation it is possible to track the path from the starting point of activation to the final point of activation. Thus it is possible to track the path of a signal across various lobes. PMID:25381107

Nisar, Humaira; Malik, Aamir Saeed; Ullah, Rafi; Shim, Seong-O; Bawakid, Abdullah; Khan, Muhammad Burhan; Subhani, Ahmad Rauf

2015-01-01

259

Seizures, refractory status epilepticus, and depolarization block as endogenous brain activities  

NASA Astrophysics Data System (ADS)

Epilepsy, refractory status epilepticus, and depolarization block are pathological brain activities whose mechanisms are poorly understood. Using a generic mathematical model of seizure activity, we show that these activities coexist under certain conditions spanning the range of possible brain activities. We perform a detailed bifurcation analysis and predict strategies to escape from some of the pathological states. Experimental results using rodent data provide support of the model, highlighting the concept that these pathological activities belong to the endogenous repertoire of brain activities.

El Houssaini, Kenza; Ivanov, Anton I.; Bernard, Christophe; Jirsa, Viktor K.

2015-01-01

260

Brain mechanical property measurement using MRE with intrinsic activation  

NASA Astrophysics Data System (ADS)

Many pathologies alter the mechanical properties of tissue. Magnetic resonance elastography (MRE) has been developed to noninvasively characterize these quantities in vivo. Typically, small vibrations are induced in the tissue of interest with an external mechanical actuator. The resulting displacements are measured with phase contrast sequences and are then used to estimate the underlying mechanical property distribution. Several MRE studies have quantified brain tissue properties. However, the cranium and meninges, especially the dura, are very effective at damping externally applied vibrations from penetrating deeply into the brain. Here, we report a method, termed ‘intrinsic activation’, that eliminates the requirement for external vibrations by measuring the motion generated by natural blood vessel pulsation. A retrospectively gated phase contrast MR angiography sequence was used to record the tissue velocity at eight phases of the cardiac cycle. The velocities were numerically integrated via the Fourier transform to produce the harmonic displacements at each position within the brain. The displacements were then reconstructed into images of the shear modulus based on both linear elastic and poroelastic models. The mechanical properties produced fall within the range of brain tissue estimates reported in the literature and, equally important, the technique yielded highly reproducible results. The mean shear modulus was 8.1 kPa for linear elastic reconstructions and 2.4 kPa for poroelastic reconstructions where fluid pressure carries a portion of the stress. Gross structures of the brain were visualized, particularly in the poroelastic reconstructions. Intra-subject variability was significantly less than the inter-subject variability in a study of six asymptomatic individuals. Further, larger changes in mechanical properties were observed in individuals when examined over time than when the MRE procedures were repeated on the same day. Cardiac pulsation, termed intrinsic activation, produces sufficient motion to allow mechanical properties to be recovered. The poroelastic model is more consistent with the measured data from brain at low frequencies than the linear elastic model. Intrinsic activation allows MRE to be performed without a device shaking the head so the patient notices no differences between it and the other sequences in an MR examination.

Weaver, John B.; Pattison, Adam J.; McGarry, Matthew D.; Perreard, Irina M.; Swienckowski, Jessica G.; Eskey, Clifford J.; Lollis, S. Scott; Paulsen, Keith D.

2012-11-01

261

Abdominal surgery activates nesfatin-1 immunoreactive brain nuclei in rats  

PubMed Central

Abdominal surgery-induced postoperative gastric ileus is well established to induce Fos expression in specific brain nuclei in rats within 2-h after surgery. However, the phenotype of activated neurons has not been thoroughly characterized. Nesfatin-1 was recently discovered in the rat hypothalamus as a new anorexigenic peptide that also inhibits gastric emptying and is widely distributed in rat brain autonomic nuclei suggesting an involvement in stress responses. Therefore, we investigated whether abdominal surgery activates nesfatin-1-immunoreactive (ir) neurons in the rat brain. Two hours after abdominal surgery with cecal palpation under short isoflurane anesthesia or anesthesia alone, rats were transcardially perfused and brains processed for double immunohistochemical labeling of Fos and nesfatin-1. Abdominal surgery, compared to anesthesia alone, induced Fos expression in neurons of the supraoptic nucleus (SON), paraventricular nucleus (PVN), locus coeruleus (LC), Edinger-Westphal nucleus (EW), rostral raphe pallidus (rRPa), nucleus of the solitary tract (NTS) and ventrolateral medulla (VLM). Double Fos/nesfatin-1 labeling showed that of the activated cells, 99% were nesfatin-1-immunoreactive in the SON, 91% in the LC, 82% in the rRPa, 74% in the EW and VLM, 71% in the anterior parvicellular PVN, 47% in the lateral magnocellular PVN, 41% in the medial magnocellular PVN, 14 % in the NTS and 9% in the medial parvicellular PVN. These data established nesfatin-1 immunoreactive neurons in specific hypothalamic and pontine nuclei as part of the neuronal response to abdominal surgery and suggest a possible implication of nesfatin-1 in the alterations of food intake and gastric transit associated with such a stressor. PMID:19944727

Stengel, Andreas; Goebel, Miriam; Wang, Lixin; Taché, Yvette

2011-01-01

262

Exploring the network dynamics underlying brain activity during rest.  

PubMed

Since the mid 1990s, the intriguing dynamics of the brain at rest has been attracting a growing body of research in neuroscience. Neuroimaging studies have revealed distinct functional networks that slowly activate and deactivate, pointing to the existence of an underlying network dynamics emerging spontaneously during rest, with specific spatial, temporal and spectral characteristics. Several theoretical scenarios have been proposed and tested with the use of large-scale computational models of coupled brain areas. However, a mechanistic explanation that encompasses all the phenomena observed in the brain during rest is still to come. In this review, we provide an overview of the key findings of resting-state activity covering a range of neuroimaging modalities including fMRI, EEG and MEG. We describe how to best define and analyze anatomical and functional brain networks and how unbalancing these networks may lead to problems with mental health. Finally, we review existing large-scale models of resting-state dynamics in health and disease. An important common feature of resting-state models is that the emergence of resting-state functional networks is obtained when the model parameters are such that the system operates at the edge of a bifurcation. At this critical working point, the global network dynamics reveals correlation patterns that are spatially shaped by the underlying anatomical structure, leading to an optimal fit with the empirical BOLD functional connectivity. However, new insights coming from recent studies, including faster oscillatory dynamics and non-stationary functional connectivity, must be taken into account in future models to fully understand the network mechanisms leading to the resting-state activity. PMID:24389385

Cabral, Joana; Kringelbach, Morten L; Deco, Gustavo

2014-03-01

263

Mapping brain activity at scale with cluster computing.  

PubMed

Understanding brain function requires monitoring and interpreting the activity of large networks of neurons during behavior. Advances in recording technology are greatly increasing the size and complexity of neural data. Analyzing such data will pose a fundamental bottleneck for neuroscience. We present a library of analytical tools called Thunder built on the open-source Apache Spark platform for large-scale distributed computing. The library implements a variety of univariate and multivariate analyses with a modular, extendable structure well-suited to interactive exploration and analysis development. We demonstrate how these analyses find structure in large-scale neural data, including whole-brain light-sheet imaging data from fictively behaving larval zebrafish, and two-photon imaging data from behaving mouse. The analyses relate neuronal responses to sensory input and behavior, run in minutes or less and can be used on a private cluster or in the cloud. Our open-source framework thus holds promise for turning brain activity mapping efforts into biological insights. PMID:25068736

Freeman, Jeremy; Vladimirov, Nikita; Kawashima, Takashi; Mu, Yu; Sofroniew, Nicholas J; Bennett, Davis V; Rosen, Joshua; Yang, Chao-Tsung; Looger, Loren L; Ahrens, Misha B

2014-09-01

264

Neuronal activity modifies DNA methylation landscape in the adult brain  

PubMed Central

DNA methylation has been traditionally viewed as a highly stable epigenetic mark in post-mitotic cells, however, postnatal brains appear to exhibit stimulus-induced methylation changes, at least in a few identified CpG dinucleotides. How extensively the neuronal DNA methylome is regulated by neuronal activity is unknown. Using a next-generation sequencing-based method for genome-wide analysis at a single-nucleotide resolution, we quantitatively compared the CpG methylation landscape of adult mouse dentate granule neurons in vivo before and after synchronous neuronal activation. About 1.4% of 219,991 CpGs measured show rapid active demethylation or de novo methylation. Some modifications remain stable for at least 24 hours. These activity-modified CpGs exhibit a broad genomic distribution with significant enrichment in low-CpG density regions, and are associated with brain-specific genes related to neuronal plasticity. Our study implicates modification of the neuronal DNA methylome as a previously under-appreciated mechanism for activity-dependent epigenetic regulation in the adult nervous system. PMID:21874013

Guo, Junjie U.; Ma, Dengke K.; Mo, Huan; Ball, Madeleine P.; Jang, Mi-Hyeon; Bonaguidi, Michael A.; Balazer, Jacob A.; Eaves, Hugh L.; Xie, Bin; Ford, Eric; Zhang, Kun; Ming, Guo-li; Gao, Yuan; Song, Hongjun

2011-01-01

265

Source localization of brain activity using helium-free interferometer  

SciTech Connect

To detect extremely small magnetic fields generated by the human brain, currently all commercial magnetoencephalography (MEG) systems are equipped with low-temperature (low-T{sub c}) superconducting quantum interference device (SQUID) sensors that use liquid helium for cooling. The limited and increasingly expensive supply of helium, which has seen dramatic price increases recently, has become a real problem for such systems and the situation shows no signs of abating. MEG research in the long run is now endangered. In this study, we report a MEG source localization utilizing a single, highly sensitive SQUID cooled with liquid nitrogen only. Our findings confirm that localization of neuromagnetic activity is indeed possible using high-T{sub c} SQUIDs. We believe that our findings secure the future of this exquisitely sensitive technique and have major implications for brain research and the developments of cost-effective multi-channel, high-T{sub c} SQUID-based MEG systems.

Dammers, Jürgen, E-mail: J.Dammers@fz-juelich.de; Chocholacs, Harald; Eich, Eberhard; Boers, Frank [Institute of Neuroscience and Medicine (INM-4), Forschungszentrum Jülich, Jülich (Germany); Faley, Michael; Dunin-Borkowski, Rafal E. [Peter Grünberg Institute (PGI-5), Forschungszentrum Jülich, Jülich (Germany); Jon Shah, N. [Institute of Neuroscience and Medicine (INM-4), Forschungszentrum Jülich, Jülich (Germany); Department of Neurology, RWTH Aachen University, Aachen (Germany); Jülich Aachen Research Alliance (JARA)—Translational Brain Medicine, Jülich (Germany)

2014-05-26

266

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

E-print Network

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

Golland, Polina

267

Neuroimaging and neuroenergetics: Brain activations as information-driven reorganization of energy flows  

E-print Network

Neuroimaging and neuroenergetics: Brain activations as information-driven reorganization of energy 25 January 2010 Keywords: Neuroimaging Neuroenergetics Brain activation Cortical response Deviance detection a b s t r a c t There is increasing focus on the neurophysiological underpinnings of brain

268

Exploring the network dynamics underlying brain activity during rest Joana Cabral a,b,  

E-print Network

Exploring the network dynamics underlying brain activity during rest§ Joana Cabral a,b, *, Morten L. Kringelbach b,c , Gustavo Deco a,d a Theoretical and Computational Neuroscience Group, Center of Brain Recerca i Estudis Avanc¸ats (ICREA), Barcelona, Spain Contents 1. Brain activity during rest

Deco, Gustavo

269

Measuring emotion in advertising research: prefrontal brain activity.  

PubMed

With the current interest in the role of emotion in advertising and advertising research, there has been an increasing interest in the use of various brain activity measures to access nonverbal emotional responses. One such approach relies on measuring the difference between left and right hemisphere prefrontal cortical activity to assess like and dislike. This approach is based on electroencephalography (EEG) and neuroimaging work, suggesting that the approach/withdrawal (frequently but not always associated with like/dislike) dimension of emotion is indicated by the balance of activity between the left and right prefrontal cortex. Much of this work was initiated by Richard Davidson in the early 1990s. An early study by Davidson et al. measured brain electrical activity to assess patterns of activation during the experience of happiness and disgust. The authors reported that disgust was found to be associated with increased right-sided activation in the frontal and anterior temporal regions compared with happiness. In contrast, happiness was found to be accompanied by left-sided activation in the anterior temporal region compared with disgust. Early reports suggested that frontal laterality indexes motivational valence with positive emotions (happy, like) associated with left greater than the right frontal activity and vice versa. Although these findings appear to be consistent with personality traits (e.g., optimism pessimism), state changes in frontal laterality appears to index approach withdraw rather than emotional valence. Interestingly, the behavioral and motivational correlates of prefrontal asymmetric activity are not restricted to humans or even primates but have been observed in numerous species such as birds and fish (see [4]). Henceforth, we use the term motivational valence (MV) rather than the more cumbersome term approach withdraw. PMID:22678836

Silberstein, Richard B; Nield, Geoffrey E

2012-01-01

270

Effects of cranial electrotherapy stimulation on resting state brain activity.  

PubMed

Cranial electrotherapy stimulation (CES) is a U.S. Food and Drug Administration (FDA)-approved treatment for insomnia, depression, and anxiety consisting of pulsed, low-intensity current applied to the earlobes or scalp. Despite empirical evidence of clinical efficacy, its mechanism of action is largely unknown. The goal was to characterize the acute effects of CES on resting state brain activity. Our primary hypothesis was that CES would result in deactivation in cortical and subcortical regions. Eleven healthy controls were administered CES applied to the earlobes at subsensory thresholds while being scanned with functional magnetic resonance imaging in the resting state. We tested 0.5- and 100-Hz stimulation, using blocks of 22 sec "on" alternating with 22 sec of baseline (device was "off"). The primary outcome measure was differences in blood oxygen level dependent data associated with the device being on versus baseline. The secondary outcome measures were the effects of stimulation on connectivity within the default mode, sensorimotor, and fronto-parietal networks. Both 0.5- and 100-Hz stimulation resulted in significant deactivation in midline frontal and parietal regions. 100-Hz stimulation was associated with both increases and decreases in connectivity within the default mode network (DMN). Results suggest that CES causes cortical brain deactivation, with a similar pattern for high- and low-frequency stimulation, and alters connectivity in the DMN. These effects may result from interference from high- or low-frequency noise. Small perturbations of brain oscillations may therefore have significant effects on normal resting state brain activity. These results provide insight into the mechanism of action of CES, and may assist in the future development of optimal parameters for effective treatment. PMID:22741094

Feusner, Jamie D; Madsen, Sarah; Moody, Teena D; Bohon, Cara; Hembacher, Emily; Bookheimer, Susan Y; Bystritsky, Alexander

2012-05-01

271

Fetal brain mTOR signaling activation in tuberous sclerosis complex.  

PubMed

Tuberous sclerosis complex (TSC) is characterized by developmental malformations of the cerebral cortex known as tubers, comprised of cells that exhibit enhanced mammalian target of rapamycin (mTOR) signaling. To date, there are no reports of mTORC1 and mTORC2 activation in fetal tubers or in neural progenitor cells lacking Tsc2. We demonstrate mTORC1 activation by immunohistochemical detection of substrates phospho-p70S6K1 (T389) and phospho-S6 (S235/236), and mTORC2 activation by substrates phospho-PKC? (S657), phospho-Akt (Ser473), and phospho-SGK1 (S422) in fetal tubers. Then, we show that Tsc2 shRNA knockdown (KD) in mouse neural progenitor cells (mNPCs) in vitro results in enhanced mTORC1 (phospho-S6, phospho-4E-BP1) and mTORC2 (phospho-Akt and phospho-NDRG1) signaling, as well as a doubling of cell size that is rescued by rapamycin, an mTORC1 inhibitor. Tsc2 KD in vivo in the fetal mouse brain by in utero electroporation causes disorganized cortical lamination and increased cell volume that is prevented with rapamycin. We demonstrate for the first time that mTORC1 and mTORC2 signaling is activated in fetal tubers and in mNPCs following Tsc2 KD. These results suggest that inhibition of mTOR pathway signaling during embryogenesis could prevent abnormal brain development in TSC. PMID:23081885

Tsai, Victoria; Parker, Whitney E; Orlova, Ksenia A; Baybis, Marianna; Chi, Anthony W S; Berg, Benjamin D; Birnbaum, Jacqueline F; Estevez, Jacqueline; Okochi, Kei; Sarnat, Harvey B; Flores-Sarnat, Laura; Aronica, Eleonora; Crino, Peter B

2014-02-01

272

Dissociable patterns of abnormal frontal cortical activation during anticipation of an uncertain reward or loss in bipolar versus major depression  

PubMed Central

Objectives Recent research has found abnormalities in reward-related neural activation in bipolar disorder (BD), during both manic and euthymic phases. However, reward-related neural activation in currently depressed individuals with BD and that in currently depressed individuals with major depressive disorder (MDD) have yet to be directly compared. Here, we studied these groups, examining the neural activation elicited during a guessing task in fronto-striatal regions identified by previous studies. Methods We evaluated neural activation during a reward task using fMRI in two groups of depressed individuals, one with bipolar I disorder (BD-I) (n = 23) and one with MDD (n = 40), with similar levels of illness severity, and a group of healthy individuals (n = 37). Results Reward expectancy-related activation in the anterior cingulate cortex was observed in the healthy individuals, but was significantly reduced in depressed patients (BD-I and MDD together). Anticipation-related activation was increased in the left ventrolateral prefrontal cortex in the BD-I depressed group compared with the other two groups. There were no significant differences in prediction error-related activation in the ventral striatum across the three groups. Conclusions The findings extend previous research which has identified dysfunction within the ventrolateral prefrontal cortex in BD, and show that abnormally elevated activity in this region during anticipation of either reward or loss may distinguish depressed individuals with BD-I from those with MDD. Altered activation of the anterior cingulate cortex during reward expectancy characterizes both types of depression. These findings have important implications for identifying both common and distinct properties of the neural circuitry underlying BD-I and MDD. PMID:24148027

Almeida, Jorge RC; Forbes, Erika E; LaBarbara, Edmund J; Phillips, Mary L

2013-01-01

273

Brain activations reflect individual discount rates in intertemporal choice.  

PubMed

Humans discount the value of future rewards following a hyperbolic function and thus may prefer a smaller immediate reward over a larger delayed reward. Marked interindividual differences in the steepness of this discounting function can be observed which can be quantified by the parameter k of the discount function. Here, we asked how differences in delay discounting behaviour are reflected by brain activation patterns. Sixteen healthy participants were studied in a slow event-related functional magnetic resonance imaging experiment at 3T. In each trial, participants had to decide between a smaller but immediately available monetary reward (ranging between 14 and 84 Euro) and a larger delayed reward (26 to 89 Euro; delay 5 to 169days) by button press. Participants had the chance to receive the reward corresponding to one of their decisions at the end of the experiment. As expected, participants differed widely with respect to the steepness of their discount function. By contrasting decisions at or near the individual participant's indifference point (as determined by parameter k) with trials either well below or well above this point two different brain networks with opposing activation patterns were revealed: Trials below or above the indifference point were associated with activation in the ventral striatum and ventromedial prefrontal cortex, whereas decisions at the indifference point gave rise to activation in medial prefrontal cortex. The opposite effects in the two systems at individual indifference point were interpreted as a reflection of response conflict. PMID:20083092

Marco-Pallarés, Josep; Mohammadi, Bahram; Samii, Amir; Münte, Thomas F

2010-03-12

274

Brain Efflux Index To Investigate the Influence of Active Efflux on Brain Distribution of Pemetrexed and Methotrexate  

PubMed Central

Antifolates, in particular methotrexate (MTX), have been widely used in the treatment of primary and secondary tumors of the central nervous system (CNS). Pemetrexed (PMX) is a novel antifolate that also exhibits potent antitumor activity against CNS malignancies. Studies have shown that brain distribution of both antifolates is significantly restricted, possible due to active efflux transport at the blood-brain barrier (BBB). This study characterizes the brain-to-blood transport of PMX and MTX and examines the role of several efflux transporters in brain distribution of the antifolates by use of the intracerebral microinjection technique (brain efflux index). The results from this study show that both PMX and MTX undergo saturable efflux transport across the BBB, with elimination half-lives of approximately 39 minutes and 29 minutes, respectively. Of the various efflux transporters this study investigated, multidrug resistance-associated protein 2 (Mrp2) does not play an important role in the brain distribution of the two antifolate drugs. Interestingly, breast-cancer resistance protein (Bcrp) makes a significant contribution to the brain elimination of MTX but not PMX. In addition, the brain-to-blood transport of both antifolates was inhibited by probenecid and benzylpenicillin, suggesting the involvement of organic anion transporters in the efflux of these compounds from the brain, with organic anion transporter 3 (Oat3) being a possibility. Our results suggest that one of the underlying mechanisms behind the limited brain distribution of PMX and MTX is active efflux transport processes at the BBB, including a benzylpenicillin-sensitive transport system and/or the active transporter Bcrp. PMID:23297298

Li, Li; Agarwal, Sagar

2013-01-01

275

Mice lacking brain-type creatine kinase activity show defective thermoregulation  

PubMed Central

The cytosolic brain-type creatine kinase and mitochondrial ubiquitous creatine kinase (CK-B and UbCKmit) are expressed during the prepubescent and adult period of mammalian life. These creatine kinase (CK) isoforms are present in neural cell types throughout the central and peripheral nervous system and in smooth muscle containing tissues, where they have an important role in cellular energy homeostasis. Here, we report on the coupling of CK activity to body temperature rhythm and adaptive thermoregulation in mice. With both brain-type CK isoforms being absent, the body temperature reproducibly drops ~1.0°C below normal during every morning (inactive) period in the daily cycle. Facultative non-shivering thermogenesis is also impaired, since CK??/?? mice develop severe hypothermia during 24 h cold exposure. A relationship with fat metabolism was suggested because comparison of CK??/?? mice with wildtype controls revealed decreased weight gain associated with less white and brown fat accumulation and smaller brown adipocytes. Also, circulating levels of glucose, triglycerides and leptin are reduced. Extensive physiological testing and uncoupling protein1 analysis showed, however, that the thermogenic problems are not due to abnormal responsiveness of brown adipocytes, since noradrenaline infusion produced a normal increase of body temperature. Moreover, we demonstrate that the cyclic drop in morning temperature is also not related to altered rhythmicity with reduced locomotion, diminished food intake or increased torpor sensitivity. Although several integral functions appear altered when CK is absent in the brain, combined findings point into the direction of inefficient neuronal transmission as the dominant factor in the thermoregulatory defect. PMID:19419668

Streijger, Femke; Pluk, Helma; Oerlemans, Frank; Beckers, Gaby; Bianco, Antonio C.; Ribeiro, Miriam O.; Wieringa, Bé; Van der Zee, Catharina E.E.M.

2010-01-01

276

Investigating the physiology of brain activation with MRI  

NASA Astrophysics Data System (ADS)

Functional magnetic resonance imaging (fMRI) has become a powerful tool for investigating the working human brain based on the blood oxygenation level dependent (BOLD) effect on the MR signal. However, despite the widespread use of fMRI techniques for mapping brain activation, the basic physiological mechanisms underlying the observed signal changes are still poorly understood. Arterial spin labeling (ASL) techniques, which measure cerebral blood flow (CBF) and the BOLD effect simultaneously, provide a useful tool for investigating these physiological questions. In this paper, recent results of studies manipulating the baseline CBF both pharmacologically and physiologically will be discussed. These data are consistent with a feed-forward mechanism of neurovascular coupling, and suggest that the CBF change itself may be a more robust reflection of neural activity changes than the BOLD effect. Consistent with these data, a new thermodynamic hypothesis is proposed for the physiological function of CBF regulation: maintenance of the [O2]/[CO2] concentration ratio at the mitochondria in order to preserve the free energy available from oxidative metabolism. A kinetic model based on this hypothesis provides a reasonable quantitative description of the CBF changes associated with neural activity and altered blood gases (CO2 and O2).

Buxton, Richard B.; Uludag, Kamil; Dubowitz, David J.

2004-04-01

277

Probabilistic analysis of activation volumes generated during deep brain stimulation.  

PubMed

Deep brain stimulation (DBS) is an established therapy for the treatment of Parkinson's disease (PD) and shows great promise for the treatment of several other disorders. However, while the clinical analysis of DBS has received great attention, a relative paucity of quantitative techniques exists to define the optimal surgical target and most effective stimulation protocol for a given disorder. In this study we describe a methodology that represents an evolutionary addition to the concept of a probabilistic brain atlas, which we call a probabilistic stimulation atlas (PSA). We outline steps to combine quantitative clinical outcome measures with advanced computational models of DBS to identify regions where stimulation-induced activation could provide the best therapeutic improvement on a per-symptom basis. While this methodology is relevant to any form of DBS, we present example results from subthalamic nucleus (STN) DBS for PD. We constructed patient-specific computer models of the volume of tissue activated (VTA) for 163 different stimulation parameter settings which were tested in six patients. We then assigned clinical outcome scores to each VTA and compiled all of the VTAs into a PSA to identify stimulation-induced activation targets that maximized therapeutic response with minimal side effects. The results suggest that selection of both electrode placement and clinical stimulation parameter settings could be tailored to the patient's primary symptoms using patient-specific models and PSAs. PMID:20974269

Butson, Christopher R; Cooper, Scott E; Henderson, Jaimie M; Wolgamuth, Barbara; McIntyre, Cameron C

2011-02-01

278

Blood-brain barrier pericytes are the main source of gamma-glutamyltranspeptidase activity in brain capillaries.  

PubMed

Cerebral endothelial cells form the selective permeability barrier between brain and blood by virtue of their impermeable tight junctions and the presence of specific carrier systems. These specialized properties of brain capillaries are reflected in the presence of proteins that are not found in other capillaries of the body. gamma-Glutamyltranspeptidase (GGT) has been widely used as a marker for brain capillaries and differentiated properties of brain endothelial cells. By using histochemical and biochemical methods we have investigated the expression of GGT in isolated capillaries, cultured brain endothelial cells and pericytes, and cocultures of astrocytes and brain endothelial cells. It was surprising that the majority of GGT activity was associated with pericytes, but not endothelial cells, suggesting that GGT is a specific marker for brain pericytes. The remaining GGT activity that was associated with endothelial cells rapidly disappeared from cultured cells but was reinduced in cocultures with astrocytes. Our results emphasize the need for pure endothelial cells for the investigation of blood-brain barrier characteristics. PMID:1345940

Risau, W; Dingler, A; Albrecht, U; Dehouck, M P; Cecchelli, R

1992-02-01

279

Real-time classification of activated brain areas for fMRI-based human-brain-interfaces  

NASA Astrophysics Data System (ADS)

Functional MR imaging (fMRI) enables to detect different activated brain areas according to the performed tasks. However, data are usually evaluated after the experiment, which prohibits intra-experiment optimization or more sophisticated applications such as biofeedback experiments. Using a human-brain-interface (HBI), subjects are able to communicate with external programs, e.g. to navigate through virtual scenes, or to experience and modify their own brain activation. These applications require the real-time analysis and classification of activated brain areas. Our paper presents first results of different strategies for real-time pattern analysis and classification realized within a flexible experiment control system that enables the volunteers to move through a 3D virtual scene in real-time using finger tapping tasks, and alternatively only thought-based tasks.

Moench, Tobias; Hollmann, Maurice; Grzeschik, Ramona; Mueller, Charles; Luetzkendorf, Ralf; Baecke, Sebastian; Luchtmann, Michael; Wagegg, Daniela; Bernarding, Johannes

2008-03-01

280

Neural activation during response inhibition differentiates blast from mechanical causes of mild to moderate traumatic brain injury.  

PubMed

Military personnel involved in Operations Enduring Freedom and Iraqi Freedom (OEF/OIF) commonly experience blast-induced mild to moderate traumatic brain injury (TBI). In this study, we used task-activated functional MRI (fMRI) to determine if blast-related TBI has a differential impact on brain activation in comparison with TBI caused primarily by mechanical forces in civilian settings. Four groups participated: (1) blast-related military TBI (milTBI; n=21); (2) military controls (milCON; n=22); (3) non-blast civilian TBI (civTBI; n=21); and (4) civilian controls (civCON; n=23) with orthopedic injuries. Mild to moderate TBI (MTBI) occurred 1 to 6 years before enrollment. Participants completed the Stop Signal Task (SST), a measure of inhibitory control, while undergoing fMRI. Brain activation was evaluated with 2 (mil, civ)×2 (TBI, CON) analyses of variance, corrected for multiple comparisons. During correct inhibitions, fMRI activation was lower in the TBI than CON subjects in regions commonly associated with inhibitory control and the default mode network. In contrast, inhibitory failures showed significant interaction effects in the bilateral inferior temporal, left superior temporal, caudate, and cerebellar regions. Specifically, the milTBI group demonstrated more activation than the milCON group when failing to inhibit; in contrast, the civTBI group exhibited less activation than the civCON group. Covariance analyses controlling for the effects of education and self-reported psychological symptoms did not alter the brain activation findings. These results indicate that the chronic effects of TBI are associated with abnormal brain activation during successful response inhibition. During failed inhibition, the pattern of activation distinguished military from civilian TBI, suggesting that blast-related TBI has a unique effect on brain function that can be distinguished from TBI resulting from mechanical forces associated with sports or motor vehicle accidents. The implications of these findings for diagnosis and treatment of TBI are discussed. PMID:24020449

Fischer, Barbara L; Parsons, Michael; Durgerian, Sally; Reece, Christine; Mourany, Lyla; Lowe, Mark J; Beall, Erik B; Koenig, Katherine A; Jones, Stephen E; Newsome, Mary R; Scheibel, Randall S; Wilde, Elisabeth A; Troyanskaya, Maya; Merkley, Tricia L; Walker, Mark; Levin, Harvey S; Rao, Stephen M

2014-01-15

281

Neural Activation during Response Inhibition Differentiates Blast from Mechanical Causes of Mild to Moderate Traumatic Brain Injury  

PubMed Central

Abstract Military personnel involved in Operations Enduring Freedom and Iraqi Freedom (OEF/OIF) commonly experience blast-induced mild to moderate traumatic brain injury (TBI). In this study, we used task-activated functional MRI (fMRI) to determine if blast-related TBI has a differential impact on brain activation in comparison with TBI caused primarily by mechanical forces in civilian settings. Four groups participated: (1) blast-related military TBI (milTBI; n=21); (2) military controls (milCON; n=22); (3) non-blast civilian TBI (civTBI; n=21); and (4) civilian controls (civCON; n=23) with orthopedic injuries. Mild to moderate TBI (MTBI) occurred 1 to 6 years before enrollment. Participants completed the Stop Signal Task (SST), a measure of inhibitory control, while undergoing fMRI. Brain activation was evaluated with 2 (mil, civ)×2 (TBI, CON) analyses of variance, corrected for multiple comparisons. During correct inhibitions, fMRI activation was lower in the TBI than CON subjects in regions commonly associated with inhibitory control and the default mode network. In contrast, inhibitory failures showed significant interaction effects in the bilateral inferior temporal, left superior temporal, caudate, and cerebellar regions. Specifically, the milTBI group demonstrated more activation than the milCON group when failing to inhibit; in contrast, the civTBI group exhibited less activation than the civCON group. Covariance analyses controlling for the effects of education and self-reported psychological symptoms did not alter the brain activation findings. These results indicate that the chronic effects of TBI are associated with abnormal brain activation during successful response inhibition. During failed inhibition, the pattern of activation distinguished military from civilian TBI, suggesting that blast-related TBI has a unique effect on brain function that can be distinguished from TBI resulting from mechanical forces associated with sports or motor vehicle accidents. The implications of these findings for diagnosis and treatment of TBI are discussed. PMID:24020449

Fischer, Barbara L.; Parsons, Michael; Durgerian, Sally; Reece, Christine; Mourany, Lyla; Lowe, Mark J.; Beall, Erik B.; Koenig, Katherine A.; Jones, Stephen E.; Newsome, Mary R.; Scheibel, Randall S.; Wilde, Elisabeth A.; Troyanskaya, Maya; Merkley, Tricia L.; Walker, Mark; Levin, Harvey S.

2014-01-01

282

Meiotic abnormalities  

SciTech Connect

Chapter 19, describes meiotic abnormalities. These include nondisjunction of autosomes and sex chromosomes, genetic and environmental causes of nondisjunction, misdivision of the centromere, chromosomally abnormal human sperm, male infertility, parental age, and origin of diploid gametes. 57 refs., 2 figs., 1 tab.

NONE

1993-12-31

283

Abnormal blood-group-Ss-active sialoglycoproteins in the membrane of Miltenberger class III, IV and V human erythrocytes.  

PubMed

1. We have studied the inherited changes occurring in the sialoglycoproteins of membranes from erythrocytes of type Miltenberger Class III (Mi.III), Miltenberger Class IV (Mi.IV) and Miltenberger Class V (Mi.V) by using sodium dodecyl sulphate/polyacrylamide gel electrophoresis and lactoperoxidase radioiodination. 2. Mi.III erythrocytes lack the normal blood-group-Ss-active sialoglycoprotein but contain an unusual s-active sialoglycoprotein of higher apparent molecular weight. A similar abnormal S-active sialoglycoprotein appears to occur in Mi.IV erythrocytes. 3. The Mi.V condition is associated with the hemizygous absence of both the normal blood-group-MN-active sialoglycoprotein and the normal Ss-active sialoglycorprotein. However, a new sialoglycoprotein component is present in these cells that has properties characteristic of both the MN-active and Ss-active sialoglycoproteins. 4. Our results suggest that the new sialoglycorportein present in Mi.V erythrocytes is a hybrid of the normal MN sialoglycoprotein and an s-active sialoglycoprotein that has properties similar to the s-active sialoglycoprotein found in Mi.III erythrocytes. We suggest that the unusual Mi.V sialoglycoprotein is derived from chromosomal misalignment with unequal crossing-over between the genes for the MN- and Ss-active sialoglycoproteins in a manner similar to that which gives rise to haemoglobin Lepore. 5. Further studies of S-s-erythrocytes confirm that these cells lack normal Ss-active sialoglycoprotein, but contain an unusual component that shows some of the properties of the normal Ss-active sialoglycoprotein. 6. Analysis of erythrocytes of type Mk/Mi.III confirms that, in addition to the known hemizygous lack of the MN-active sialoglycoprotein, the Mk condition is also associated with a loss of the Ss-active sialoglycoprotein. 7. In order to facilitate discussion of the complex changes that occur in these variant erythrocytes, a new unified nomenclature is used for the erythrocyte sialoglycoproteins. PMID:230820

Anstee, D J; Mawby, W J; Tanner, M J

1979-11-01

284

No evidence for GNAS copy number variants in patients with features of Albright's hereditary osteodystrophy and abnormal platelet Gs activity.  

PubMed

Albright's hereditary osteodystrophy (AHO) is characterized by short stature, round face, calcifications, obesity, brachydactyly and intellectual disability. AHO without hormone resistance is called pseudopseudohypoparathyroidism (PPHP), a rare clinical condition difficult to diagnose with highly variable features. PPHP is caused by paternally inherited loss-of-function mutations in the GNAS. Patients with 2q37 microdeletions or HDAC4 mutations are also defined as having an AHO-like phenotype with normal stimulatory G (Gs) function. We have studied 256 patients with AHO features but no other diagnosis. Their platelet Gs activity was determined via the aggregation-inhibition test showing Gs hypo- or hyperfuncton in 24% and 15% of the patients, respectively. Before initiating with detailed (epi)genetic GNAS studies, we here wanted to excluded copy number variants (CNVs) in GNAS as cause of AHO with a novel large-scale screening technique. Multiplex amplicon quantification (MAQ) for CNVs screening was developed for the 20q13.3 region including GNAS and potential long-range imprinting control elements such as STX16. This is the first large-scale GNAS CNV study in patients with common AHO features but no CNVs were detected. In conclusion, CNVs in the GNAS region are not likely to cause an AHO-like phenotype with or without abnormal platelet Gs activity. Future studies will be undertaken to find out whether these AHO patients with abnormal Gs function are characterized by GNAS coding or methylation defects. PMID:22277900

Izzi, Benedetta; de Zegher, Francis; Francois, Inge; del Favero, Jurgen; Goossens, Dirk; Wittevrongel, Christine; Thys, Chantal; Van Geet, Chris; Freson, Kathleen

2012-04-01

285

Aligning context-based statistical models of language with brain activity during reading  

E-print Network

Aligning context-based statistical models of language with brain activity during reading Leila for incoming words given the context. On the other hand, brain imaging studies have sug- gested that during reading, the brain (a) continu- ously builds a context from the successive words and every time

Knight, Kevin

286

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

ERIC Educational Resources Information Center

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

Baslow, Morris H.; Guilfoyle, David N.

2007-01-01

287

Brain Computer Interface Vs Walking Interface in VR: The Impact of Motor Activity on Spatial Transfer  

E-print Network

Brain Computer Interface Vs Walking Interface in VR: The Impact of Motor Activity on Spatial-based and vestibular information). The second one, a brain computer interface (BCI), enables the user to navigate, Navigation, Virtual Reality, Spatial Cognition, Treadmill, Brain Computer Interface, User Study. 1

Boyer, Edmond

288

Written distractor words influence brain activity during overt picture naming  

PubMed Central

Language production requires multiple stages of processing (e.g., semantic retrieval, lexical selection), each of which may involve distinct brain regions. Distractor words can be combined with picture naming to examine factors that influence language production. Phonologically-related distractors have been found to speed picture naming (facilitation), while slower response times and decreased accuracy (interference) generally occur when a distractor is categorically related to the target image. However, other types of semantically-related distractors have been reported to produce a facilitative effect (e.g., associative, part-whole). The different pattern of results for different types of semantically-related distractors raises the question about how the nature of the semantic relation influences the effect of the distractor. To explore the nature of these semantic effects further, we used functional MRI to examine the influence of four types of written distractors on brain activation during overt picture naming. Distractors began with the same sound, were categorically-related, part of the object to be named, or were unrelated to the picture. Phonologically-related trials elicited greater activation than both semantic conditions (categorically-related and part-whole) in left insula and bilateral parietal cortex, regions that have been attributed to phonological aspects of production and encoding, respectively. Semantic conditions elicited greater activation than phonological trials in left posterior MTG, a region that has been linked to concept retrieval and semantic integration. Overall, the two semantic conditions did not differ substantially in their functional activation which suggests a similarity in the semantic demands and lexical competition across these two conditions. PMID:24715859

Diaz, Michele T.; Hogstrom, Larson J.; Zhuang, Jie; Voyvodic, James T.; Johnson, Micah A.; Camblin, C. Christine

2014-01-01

289

Accumulated source imaging of brain activity with both low and high-frequency neuromagnetic signals  

PubMed Central

Recent studies have revealed the importance of high-frequency brain signals (>70 Hz). One challenge of high-frequency signal analysis is that the size of time-frequency representation of high-frequency brain signals could be larger than 1 terabytes (TB), which is beyond the upper limits of a typical computer workstation's memory (<196 GB). The aim of the present study is to develop a new method to provide greater sensitivity in detecting high-frequency magnetoencephalography (MEG) signals in a single automated and versatile interface, rather than the more traditional, time-intensive visual inspection methods, which may take up to several days. To address the aim, we developed a new method, accumulated source imaging, defined as the volumetric summation of source activity over a period of time. This method analyzes signals in both low- (1~70 Hz) and high-frequency (70~200 Hz) ranges at source levels. To extract meaningful information from MEG signals at sensor space, the signals were decomposed to channel-cross-channel matrix (CxC) representing the spatiotemporal patterns of every possible sensor-pair. A new algorithm was developed and tested by calculating the optimal CxC and source location-orientation weights for volumetric source imaging, thereby minimizing multi-source interference and reducing computational cost. The new method was implemented in C/C++ and tested with MEG data recorded from clinical epilepsy patients. The results of experimental data demonstrated that accumulated source imaging could effectively summarize and visualize MEG recordings within 12.7 h by using approximately 10 GB of computer memory. In contrast to the conventional method of visually identifying multi-frequency epileptic activities that traditionally took 2–3 days and used 1–2 TB storage, the new approach can quantify epileptic abnormalities in both low- and high-frequency ranges at source levels, using much less time and computer memory. PMID:24904402

Xiang, Jing; Luo, Qian; Kotecha, Rupesh; Korman, Abraham; Zhang, Fawen; Luo, Huan; Fujiwara, Hisako; Hemasilpin, Nat; Rose, Douglas F.

2014-01-01

290

Abnormal vitamin K metabolism in the presence of normal clotting factor activity in factory workers exposed to 4-hydroxycoumarins.  

PubMed Central

The case histories of two patients exposed to the novel anticoagulants brodifacoum and difenacoum are reported. Abnormal vitamin K1 metabolism, as indicated by elevated vitamin K1 2,3-epoxide plasma concentrations after i.v. administration of vitamin K1, could be detected for more than 18 months after exposure to the anticoagulants. There was a marked prolongation of prothrombin time (greater than 50 s) in both cases, at the time of exposure. However, subsequent haematological investigations (prothrombin time and vitamin K-dependent clotting factor activity) have been shown to be normal in both cases for at least 18 months. These cases confirm the long-acting nature of brodifacoum and difenacoum and present an apparent dissociation between the effect of coumarin anticoagulants on vitamin K1 metabolism and clotting factor activity. PMID:3964529

Park, B K; Choonara, I A; Haynes, B P; Breckenridge, A M; Malia, R G; Preston, F E

1986-01-01

291

Recovery of brain and plasma cholinesterase activities in ducklings exposed to organophosphorus pesticides  

Microsoft Academic Search

Brain and plasma cholinesterase (ChE) activities were determined for mallard ducklings (Anas platyrhynchos) exposed to dicrotophos and fenthion. Recovery rates of brain ChE did not differ between ducklings administered a single oral dose vs. a 2-week dietary dose of these organophosphates. Exposure to the organophosphates, followed by recovery of brain ChE, did not significantly affect the degree of brain ChE

W. James Fleming

1981-01-01

292

3-hydroxyanthranilate Oxygenase Activity is Increased in the Brains of Huntington Disease Victims  

Microsoft Academic Search

An excess of the tryptophan metabolite quinolinic acid in the brain has been hypothetically related to the pathogenesis of Huntington disease. Quinolinate's immediate biosynthetic enzyme, 3-hydroxyanthranilate oxygenase (EC 1.13.11.6), has now been detected in human brain tissue. The activity of 3-hydroxyanthranilate oxygenase is increased in Huntington disease brains as compared to control brains. The increment is particularly pronounced in the

Robert Schwarcz; Etsuo Okuno; Robert J. White; Edward D. Bird; William O. Whetsell

1988-01-01

293

Anti-platelet-activating factor, antibacterial, and antiradical activities of lipids extract from silver carp brain  

PubMed Central

Background Epidemiological studies have verified the protective role of fish lipids in cardiovascular diseases. However, the effects of fish lipids on health boost remain undefined. Large amounts of by-products, such as fish brain which contains high level of lipids, are produced with silver carp processing. Fish brain is rich in bioactive lipids which are overwhelmingly effective in preventing cardiovascular diseases. The aim of this study was to elucidate the pharmacological activities of silver carp brain lipids against diseases by inhibiting platelet-activating factor (PAF), suppressing bacterial growth and scavenging free radicals. Methods Total lipids (TL) were extracted from silver carp brain and separated into polar lipids (PL) and neutral lipids (NL). The capabilities of the lipid fractions in aggregating washed rabbit platelet or in inhibiting PAF-induced platelet aggregation were tested. Their antibacterial and antiradical activities were studied as well. Results The lipid fractions exhibited strong inhibitory activities, and the activity of TL was mainly attributed to NL. TL exhibited antibacterial activity towards Staphylococcus aureus, while NL managed to fight against S. aureus and Escherichia coli. PL excelled TL and NL in simultaneously suppressing the growths of Shigella dysenteriae and Salmonella typhi besides those of S. aureus and E. coli. The scavenging effect of PL on 2,2-diphenyl-1-picrylhydrazyl radical was considerably higher than those of TL and NL. Conclusion The present study may help to explain the protective role of fish lipids against diseases and may be responsible for the effectiveness of fish brain in benefiting health. PMID:23805935

2013-01-01

294

Feeling Abnormal: Simulation of Deviancy in Abnormal and Exceptionality Courses.  

ERIC Educational Resources Information Center

Describes activity in which student in abnormal psychology and psychology of exceptional children classes personally experience being judged abnormal. The experience allows the students to remember relevant research, become sensitized to the feelings of individuals classified as deviant, and use caution in classifying individuals as abnormal.…

Fernald, Charles D.

1980-01-01

295

Effect of stunning on spontaneous physical activity and evoked activity in the brain  

Microsoft Academic Search

1. The effect of stunning current on the time to recovery of physical activity, and on somatosensory evoked potentials (SEPs) in the brain, was examined in broiler chickens.2. Increasing stunning current was associated with an increase in the time to recovery of tension in the neck muscles and with an increase in the incidence of loss of SEPs.3. Currents greater

N. G. Gregory; S. B. Wotton

1990-01-01

296

FXR activation reverses insulin resistance and lipid abnormalities and protects against liver steatosis in Zucker (fa/fa) obese rats.  

PubMed

The farnesoid X receptor (FXR) is a bile acid activated nuclear receptor. Zucker (fa/fa) rats, harboring a loss of function mutation of the leptin receptor, develop diabetes, insulin resistance, obesity, and liver steatosis. In this study, we investigated the effect of FXR activation by 6-ethyl-chenodeoxycholic acid, (6E-CDCA, 10 mg/kg) on insulin resistance and liver and muscle lipid metabolism in fa/fa rats and compared its activity with rosiglitazone (10 mg/kg) alone or in combination with 6E-CDCA (5 mg/kg each). In comparison to lean (fa/+), fa/fa rats on a normal diet developed insulin resistance and liver steatosis. FXR activation protected against body weight gain and liver and muscle fat deposition and reversed insulin resistance as assessed by insulin responsive substrate-1 phosphorylation on serine 312 in liver and muscles. Activation of FXR reduced liver expression of genes involved in fatty acid synthesis, lipogenesis, and gluconeogenesis. In the muscles, FXR treatment reduced free fatty acid synthesis. Rosiglitazone reduced blood insulin, glucose, triglyceride, free fatty acid, and cholesterol plasma levels but promoted body weight gain (20%) and liver fat deposition. FXR activation reduced high density lipoprotein plasma levels. In summary, FXR administration reversed insulin resistance and correct lipid metabolism abnormalities in an obesity animal model. PMID:19783811

Cipriani, Sabrina; Mencarelli, Andrea; Palladino, Giuseppe; Fiorucci, Stefano

2010-04-01

297

Males and females differ in brain activation during cognitive tasks.  

PubMed

To examine the effect of gender on regional brain activity, we utilized functional magnetic resonance imaging (fMRI) during a motor task and three cognitive tasks; a word generation task, a spatial attention task, and a working memory task in healthy male (n = 23) and female (n = 10) volunteers. Functional data were examined for group differences both in the number of pixels activated, and the blood-oxygen-level-dependent (BOLD) magnitude during each task. Males had a significantly greater mean activation than females in the working memory task with a greater number of pixels being activated in the right superior parietal gyrus and right inferior occipital gyrus, and a greater BOLD magnitude occurring in the left inferior parietal lobe. However, despite these fMRI changes, there were no significant differences between males and females on cognitive performance of the task. In contrast, in the spatial attention task, men performed better at this task than women, but there were no significant functional differences between the two groups. In the word generation task, there were no external measures of performance, but in the functional measurements, males had a significantly greater mean activation than females, where males had a significantly greater BOLD signal magnitude in the left and right dorsolateral prefrontal cortex, the right inferior parietal lobe, and the cingulate. In neither of the motor tasks (right or left hand) did males and females perform differently. Our fMRI findings during the motor tasks were a greater mean BOLD signal magnitude in males in the right hand motor task, compared to females where males had an increased BOLD signal magnitude in the right inferior parietal gyrus and in the left inferior frontal gyrus. In conclusion, these results demonstrate differential patterns of activation in males and females during a variety of cognitive tasks, even though performance in these tasks may not vary, and also that variability in performance may not be reflected in differences in brain activation. These results suggest that in functional imaging studies in clinical populations it may be sensible to examine each sex independently until this effect is more fully understood. PMID:16260156

Bell, Emily C; Willson, Morgan C; Wilman, Alan H; Dave, Sanjay; Silverstone, Peter H

2006-04-01

298

The un-rested resting brain: Sleep-deprivation alters activity within the default-mode network  

PubMed Central

The sleep-deprived brain has principally been characterized by examining dysfunction during cognitive-task performance. However, far less attention has been afforded the possibility that sleep deprivation may be as, if not more, accurately characterized on the basis of abnormal resting-state brain activity. Here we report that one night of sleep deprivation significantly disrupts the canonical signature of task-related deactivation, resulting in a double dissociation within anterior as well as posterior midline regions of the default network. Indeed, deactivation within these regions alone discriminated sleep-deprived from sleep-control subjects with a 93% degree of sensitivity and 92% specificity. In addition, the relative balance of deactivation within these default nodes significantly correlated with the amount of prior sleep in the control group (and not extended time awake in the deprivation group). Therefore, the stability and balance of task-related deactivation in key default-mode regions may be dependent on prior sleep, such that a lack thereof disrupts this signature pattern of brain activity; findings that may offer explanatory insights into conditions associated with sleep loss at both a clinical as well as societal level. PMID:19702469

Gujar, Ninad; Yoo, Seung-Schik; Hu, Peter; Walker, Matthew P.

2010-01-01

299

Real-time classification of activated brain areas for fMRI-based human-brain-interfaces  

Microsoft Academic Search

Functional MR imaging (fMRI) enables to detect different activated brain areas according to the performed tasks. However, data are usually evaluated after the experiment, which prohibits intra-experiment optimization or more sophisticated applications such as biofeedback experiments. Using a human-brain-interface (HBI), subjects are able to communicate with external programs, e.g. to navigate through virtual scenes, or to experience and modify their

Tobias Moench; Maurice Hollmann; Ramona Grzeschik; Charles Mueller; Ralf Luetzkendorf; Sebastian Baecke; Michael Luchtmann; Daniela Wagegg; Johannes Bernarding

2008-01-01

300

Tasting calories differentially affects brain activation during hunger and satiety.  

PubMed

An important function of eating is ingesting energy. Our objectives were to assess whether oral exposure to caloric and non-caloric stimuli elicits discriminable responses in the brain and to determine in how far these responses are modulated by hunger state and sweetness. Thirty women tasted three stimuli in two motivational states (hunger and satiety) while their brain responses were measured using functional magnetic resonance imaging in a randomized crossover design. Stimuli were solutions of sucralose (sweet, no energy), maltodextrin (non-sweet, energy) and sucralose+maltodextrin (sweet, energy). We found no main effect of energy content and no interaction between energy content and sweetness. However, there was an interaction between hunger state and energy content in the median cingulate (bilaterally), ventrolateral prefrontal cortex, anterior insula and thalamus. This indicates that the anterior insula and thalamus, areas in which hunger state and taste of a stimulus are integrated, also integrate hunger state with caloric content of a taste stimulus. Furthermore, in the median cingulate and ventrolateral prefrontal cortex, tasting energy resulted in more activation during satiety compared to hunger. This finding indicates that these areas, which are known to be involved in processes that require approach and avoidance, are also involved in guiding ingestive behavior. In conclusion, our results suggest that energy sensing is a hunger state dependent process, in which the median cingulate, ventrolateral prefrontal cortex, anterior insula and thalamus play a central role by integrating hunger state with stimulus relevance. PMID:25449847

van Rijn, Inge; de Graaf, Cees; Smeets, Paul A M

2015-02-15

301

Congenital Abnormalities  

MedlinePLUS

... Ask your pediatrician for a referral to a genetic counseling service . These services have expertise with a variety ... Family Health History & Genetics Detecting Genetic Abnormalities Prenatal Genetic Counseling Children with Down Syndrome: Health Care Information for ...

302

Activity Recognition and Abnormality Detection with the Switching Hidden Semi-Markov Model  

Microsoft Academic Search

This paper addresses the problem of learning and rec- ognizing human activities of daily living (ADL), which is an important research issue in building a pervasive and smart environment. In dealing with ADL, we argue that it is beneficial to exploit both the inherent hierarchical or- ganization of the activities and their typical duration. To this end, we introduce the

Thi V. Duong; Hung Hai Bui; Dinh Q. Phung; Svetha Venkatesh

2005-01-01

303

Abnormal error-related antisaccade activation in premanifest and early manifest Huntington disease  

PubMed Central

Objective Individuals with the trinucleotide CAG expansion (CAG+) that causes Huntington disease (HD) have impaired performance on antisaccade (AS) tasks that require directing gaze in the mirror opposite direction of visual targets. This study aimed to identify the neural substrates underlying altered antisaccadic performance. Method Three groups of participants were recruited: 1) Imminent and early manifest HD (early HD, n=8); 2) premanifest (presymptomatic) CAG+ (preHD, n=10); and 3) CAG unexpanded (CAG?) controls (n=12). All participants completed a uniform study visit that included a neurological evaluation, neuropsychological battery, molecular testing, and functional magnetic resonance imaging during an AS task. The blood oxygenation level dependent (BOLD) response was obtained during saccade preparation and saccade execution for both correct and incorrect responses using regression analysis. Results Significant group differences in BOLD response were observed when comparing incorrect AS to correct AS execution. Specifically, as the percentage of incorrect AS increased, BOLD responses in the CAG? group decreased progressively in a well-documented reward detection network that includes the pre-supplementary motor area and dorsal anterior cingulate cortex. In contrast, AS errors in the preHD and early HD groups lacked this relationship with BOLD signal in the error detection network, and BOLD responses to AS errors were smaller in the two CAG+ groups as compared with the CAG? group. Conclusions These results are the first to suggest that abnormalities in an error-related response network may underlie early changes in AS eye movements in premanifest and early manifest HD. PMID:21401260

Rupp, J.; Dzemidzic, M.; Blekher, T.; Bragulat, V.; West, J.; Jackson, J.; Hui, S.; Wojcieszek, J.; Saykin, A.J.; Kareken, D.; Foroud, T.

2010-01-01

304

Platelet activating factor induces transient blood-brain barrier opening to facilitate edaravone penetration into the brain.  

PubMed

The blood-brain barrier (BBB) greatly limits the efficacy of many neuroprotective drugs' delivery to the brain, so improving drug penetration through the BBB has been an important focus of research. Here we report that platelet activating factor (PAF) transiently opened BBB and facilitated neuroprotectant edaravone penetration into the brain. Intravenous infusion with PAF induced a transient BBB opening in rats, reflected by increased Evans blue leakage and mild edema formation, which ceased within 6 h. Furthermore, rat regional cerebral blood flow (rCBF) declined acutely during PAF infusion, but recovered slowly. More importantly, this transient BBB opening significantly increased the penetration of edaravone into the brain, evidenced by increased edaravone concentrations in tissue interstitial fluid collected by microdialysis and analyzed by Ultra-performance liquid chromatograph combined with a hybrid quadrupole time-of-flight mass spectrometer (UPLC-MS/MS). Similarly, incubation of rat brain microvessel endothelial cells monolayer with 1 ?M PAF for 1 h significantly increased monolayer permeability to (125)I-albumin, which recovered 1 h after PAF elimination. However, PAF incubation with rat brain microvessel endothelial cells for 1 h did not cause detectable cytotoxicity, and did not regulate intercellular adhesion molecule-1, matrix-metalloproteinase-9 and P-glycoprotein expression. In conclusion, PAF could induce transient and reversible BBB opening through abrupt rCBF decline, which significantly improved edaravone penetration into the brain. Platelet activating factor (PAF) transiently induces BBB dysfunction and increases BBB permeability, which may be due to vessel contraction and a temporary decline of regional cerebral blood flow (rCBF) triggered by PAF. More importantly, the PAF induced transient BBB opening facilitates neuroprotectant edaravone penetration into brain. The results of this study may provide a new approach to improve drug delivery into the brain. PMID:24164378

Fang, Weirong; Zhang, Rui; Sha, Lan; Lv, Peng; Shang, Erxin; Han, Dan; Wei, Jie; Geng, Xiaohan; Yang, Qichuan; Li, Yunman

2014-03-01

305

Brain fatty acid synthase activates PPARalpha to maintain energy homeostasis.  

PubMed

Central nervous system control of energy balance affects susceptibility to obesity and diabetes, but how fatty acids, malonyl-CoA, and other metabolites act at this site to alter metabolism is poorly understood. Pharmacological inhibition of fatty acid synthase (FAS), rate limiting for de novo lipogenesis, decreases appetite independently of leptin but also promotes weight loss through activities unrelated to FAS inhibition. Here we report that the conditional genetic inactivation of FAS in pancreatic beta cells and hypothalamus produced lean, hypophagic mice with increased physical activity and impaired hypothalamic PPARalpha signaling. Administration of a PPARalpha agonist into the hypothalamus increased PPARalpha target genes and normalized food intake. Inactivation of beta cell FAS enzyme activity had no effect on islet function in culture or in vivo. These results suggest a critical role for brain FAS in the regulation of not only feeding, but also physical activity, effects that appear to be mediated through the provision of ligands generated by FAS to PPARalpha. Thus, 2 diametrically opposed proteins, FAS (induced by feeding) and PPARalpha (induced by starvation), unexpectedly form an integrative sensory module in the central nervous system to orchestrate energy balance. PMID:17694178

Chakravarthy, Manu V; Zhu, Yimin; López, Miguel; Yin, Li; Wozniak, David F; Coleman, Trey; Hu, Zhiyuan; Wolfgang, Michael; Vidal-Puig, Antonio; Lane, M Daniel; Semenkovich, Clay F

2007-09-01

306

Brain projects think big When you read these words, hundreds of million of nerve cells are electrically and chemically active in your brain. This  

E-print Network

Brain projects think big When you read these words, hundreds of million of nerve cells are electrically and chemically active in your brain. This activity enables you to recognize words, sense the world, learn, enjoy and create new things, and be curious about the world around you. Indeed, our brain

Segev, Idan

307

Neurological abnormalities in caveolin-1 knock out mice.  

PubMed

Caveolin-1 is the defining structural protein in caveolar vesicles, which regulate signal transduction and cholesterol trafficking in cells. In the brain, cav-1 is highly expressed in neurons and glia, but its function in those cell types is unclear. Mice deficient in cav-1 (CavKO) have been developed to test functional roles for cav-1 in various tissues. However, neurological phenotypes associated with loss of cav-1 in mice have not been evaluated. Here, we report the results of motor and behavioral testing of CavKO mice. We find that mice deficient in cav-1 have reduced brain weight and display a number of motor and behavioral abnormalities. CavKO mice develop neurological phenotypes including clasping, abnormal spinning, muscle weakness, reduced activity, and gait abnormalities. These data suggest that cav-1 is involved in maintaining cortico-striato-pallido-thalamo-pontine pathways associated with motor control. PMID:16750274

Trushina, Eugenia; Du Charme, Jordan; Parisi, Joseph; McMurray, Cynthia T

2006-09-15

308

Anatomically realistic multiscale models of normal and abnormal gastrointestinal electrical activity  

PubMed Central

One of the major aims of the International Union of Physiological Sciences (IUPS) Physiome Project is to develop multiscale mathematical and computer models that can be used to help understand human health. We present here a small facet of this broad plan that applies to the gastrointestinal system. Specifically, we present an anatomically and physiologically based modelling framework that is capable of simulating normal and pathological electrical activity within the stomach and small intestine. The continuum models used within this framework have been created using anatomical information derived from common medical imaging modalities and data from the Visible Human Project. These models explicitly incorporate the various smooth muscle layers and networks of interstitial cells of Cajal (ICC) that are known to exist within the walls of the stomach and small bowel. Electrical activity within individual ICCs and smooth muscle cells is simulated using a previously published simplified representation of the cell level electrical activity. This simulated cell level activity is incorporated into a bidomain representation of the tissue, allowing electrical activity of the entire stomach or intestine to be simulated in the anatomically derived models. This electrical modelling framework successfully replicates many of the qualitative features of the slow wave activity within the stomach and intestine and has also been used to investigate activity associated with functional uncoupling of the stomach. PMID:17457969

Cheng, Leo K; Komuro, Rie; Austin, Travis M; Buist, Martin L; Pullan, Andrew J

2007-01-01

309

Control of Abnormal Synchronization in Neurological Disorders  

PubMed Central

In the nervous system, synchronization processes play an important role, e.g., in the context of information processing and motor control. However, pathological, excessive synchronization may strongly impair brain function and is a hallmark of several neurological disorders. This focused review addresses the question of how an abnormal neuronal synchronization can specifically be counteracted by invasive and non-invasive brain stimulation as, for instance, by deep brain stimulation for the treatment of Parkinson’s disease, or by acoustic stimulation for the treatment of tinnitus. On the example of coordinated reset (CR) neuromodulation, we illustrate how insights into the dynamics of complex systems contribute to successful model-based approaches, which use methods from synergetics, non-linear dynamics, and statistical physics, for the development of novel therapies for normalization of brain function and synaptic connectivity. Based on the intrinsic multistability of the neuronal populations induced by spike timing-dependent plasticity (STDP), CR neuromodulation utilizes the mutual interdependence between synaptic connectivity and dynamics of the neuronal networks in order to restore more physiological patterns of connectivity via desynchronization of neuronal activity. The very goal is to shift the neuronal population by stimulation from an abnormally coupled and synchronized state to a desynchronized regime with normalized synaptic connectivity, which significantly outlasts the stimulation cessation, so that long-lasting therapeutic effects can be achieved. PMID:25566174

Popovych, Oleksandr V.; Tass, Peter A.

2014-01-01

310

Whole-brain mapping of behaviourally induced neural activation in mice.  

PubMed

The ability to visualize behaviourally evoked neural activity patterns across the rodent brain is essential for understanding the distributed brain networks mediating particular behaviours. However, current imaging methods are limited in their spatial resolution and/or ability to obtain brain-wide coverage of functional activity. Here, we describe a new automated method for obtaining cellular-level, whole-brain maps of behaviourally induced neural activity in the mouse. This method combines the use of transgenic immediate-early gene reporter mice to visualize neural activity; serial two-photon tomography to image the entire brain at cellular resolution; advanced image processing algorithms to count the activated neurons and align the datasets to the Allen Mouse Brain Atlas; and statistical analysis to identify the network of activated brain regions evoked by behaviour. We demonstrate the use of this approach to determine the whole-brain networks activated during the retrieval of fear memories. Consistent with previous studies, we identified a large network of amygdalar, hippocampal, and neocortical brain regions implicated in fear memory retrieval. Our proposed methods can thus be used to map cellular networks involved in the expression of normal behaviours as well as to investigate in depth circuit dysfunction in mouse models of neurobiological disease. PMID:24760545

Vousden, Dulcie A; Epp, Jonathan; Okuno, Hiroyuki; Nieman, Brian J; van Eede, Matthijs; Dazai, Jun; Ragan, Timothy; Bito, Haruhiko; Frankland, Paul W; Lerch, Jason P; Henkelman, R Mark

2014-04-24

311

Mapping social behavior-induced brain activation at cellular resolution in the mouse.  

PubMed

Understanding how brain activation mediates behaviors is a central goal of systems neuroscience. Here, we apply an automated method for mapping brain activation in the mouse in order to probe how sex-specific social behaviors are represented in the male brain. Our method uses the immediate-early-gene c-fos, a marker of neuronal activation, visualized by serial two-photon tomography: the c-fos-GFP+ neurons are computationally detected, their distribution is registered to a reference brain and a brain atlas, and their numbers are analyzed by statistical tests. Our results reveal distinct and shared female and male interaction-evoked patterns of male brain activation representing sex discrimination and social recognition. We also identify brain regions whose degree of activity correlates to specific features of social behaviors and estimate the total numbers and the densities of activated neurons per brain areas. Our study opens the door to automated screening of behavior-evoked brain activation in the mouse. PMID:25558063

Kim, Yongsoo; Venkataraju, Kannan Umadevi; Pradhan, Kith; Mende, Carolin; Taranda, Julian; Turaga, Srinivas C; Arganda-Carreras, Ignacio; Ng, Lydia; Hawrylycz, Michael J; Rockland, Kathleen S; Seung, H Sebastian; Osten, Pavel

2015-01-13

312

Mechanisms of brain ventricle development  

E-print Network

The brain ventricles are a conserved system of fluid-filled cavities within the brain that form during the earliest stages of brain development. Abnormal brain ventricle development has been correlated with neurodevelopmental ...

Lowery, Laura Anne

2008-01-01

313

Brain Na(+), K(+)-ATPase Activity In Aging and Disease.  

PubMed

Na(+)/K(+) pump or sodium- and potassium-activated adenosine 5'-triphosphatase (Na(+), K(+)-ATPase), its enzymatic version, is a crucial protein responsible for the electrochemical gradient across the cell membranes. It is an ion transporter, which in addition to exchange cations, is the ligand for cardenolides. This enzyme regulates the entry of K(+) with the exit of Na(+) from cells, being the responsible for Na(+)/K(+) equilibrium maintenance through neuronal membranes. This transport system couples the hydrolysis of one molecule of ATP to exchange three sodium ions for two potassium ions, thus maintaining the normal gradient of these cations in animal cells. Oxidative metabolism is very active in brain, where large amounts of chemical energy as ATP molecules are consumed, mostly required for the maintenance of the ionic gradients that underlie resting and action potentials which are involved in nerve impulse propagation, neurotransmitter release and cation homeostasis. Protein phosphorylation is a key process in biological regulation. At nervous system level, protein phosphorylation is the major molecular mechanism through which the function of neural proteins is modulted in response to extracellular signals, including the response to neurotransmitter stimuli. It is the major mechanism of neural plasticity, including memory processing. The phosphorylation of Na(+), K(+)-ATPase catalytic subunit inhibits enzyme activity whereas the inhibition of protein kinase C restores the enzyme activity. The dephosphorylation of neuronal Na(+), K(+)-ATPase is mediated by calcineurin, a serine / threonine phosphatase. The latter enzyme is involved in a wide range of cellular responses to Ca(2+) mobilizing signals, in the regulation of neuronal excitability by controlling the activity of ion channels, in the release of neurotransmitters and hormones, as well as in synaptic plasticity and gene transcription. In the present article evidence showing Na(+), K(+)-ATPase involvement in signaling pathways, enzyme changes in diverse neurological diseases as well as during aging, have been summarized. Issues refer mainly to Na(+), K(+)-ATPase studies in ischemia, brain injury, depression and mood disorders, mania, stress, Alzheimer´s disease, learning and memory, and neuronal hyperexcitability and epilepsy. PMID:25018677

de Lores Arnaiz, Georgina Rodríguez; Ordieres, María Graciela López

2014-06-01

314

Brain Na+, K+-ATPase Activity In Aging and Disease  

PubMed Central

Na+/K+ pump or sodium- and potassium-activated adenosine 5’-triphosphatase (Na+, K+-ATPase), its enzymatic version, is a crucial protein responsible for the electrochemical gradient across the cell membranes. It is an ion transporter, which in addition to exchange cations, is the ligand for cardenolides. This enzyme regulates the entry of K+ with the exit of Na+ from cells, being the responsible for Na+/K+ equilibrium maintenance through neuronal membranes. This transport system couples the hydrolysis of one molecule of ATP to exchange three sodium ions for two potassium ions, thus maintaining the normal gradient of these cations in animal cells. Oxidative metabolism is very active in brain, where large amounts of chemical energy as ATP molecules are consumed, mostly required for the maintenance of the ionic gradients that underlie resting and action potentials which are involved in nerve impulse propagation, neurotransmitter release and cation homeostasis. Protein phosphorylation is a key process in biological regulation. At nervous system level, protein phosphorylation is the major molecular mechanism through which the function of neural proteins is modulted in response to extracellular signals, including the response to neurotransmitter stimuli. It is the major mechanism of neural plasticity, including memory processing. The phosphorylation of Na+, K+-ATPase catalytic subunit inhibits enzyme activity whereas the inhibition of protein kinase C restores the enzyme activity. The dephosphorylation of neuronal Na+, K+-ATPase is mediated by calcineurin, a serine / threonine phosphatase. The latter enzyme is involved in a wide range of cellular responses to Ca2+ mobilizing signals, in the regulation of neuronal excitability by controlling the activity of ion channels, in the release of neurotransmitters and hormones, as well as in synaptic plasticity and gene transcription. In the present article evidence showing Na+, K+-ATPase involvement in signaling pathways, enzyme changes in diverse neurological diseases as well as during aging, have been summarized. Issues refer mainly to Na+, K+-ATPase studies in ischemia, brain injury, depression and mood disorders, mania, stress, Alzheimer´s disease, learning and memory, and neuronal hyperexcitability and epilepsy. PMID:25018677

de Lores Arnaiz, Georgina Rodríguez; Ordieres, María Graciela López

2014-01-01

315

Abnormal muscle activation during gait in diabetes patients with and without neuropathy.  

PubMed

The World Health Organization warns that, in 2000, as many as 33 million Europeans suffered from diabetes, approximately 15% will likely develop foot ulcers, and approximately 15-20% of these patients will face lower-extremity amputation. Changes in some gait parameters that appear to be specific in diabetes have been identified in the literature: shorter stride length, reduced walking speed, and altered lower limb and trunk mobility. The present study aimed at evaluating the role of altered muscle activity in gait alterations of diabetic subjects with and without neuropathy. This study involved 50 subjects: 10 controls (BMI 24.4 ± 2.8, age 61.2 ± 5.07), 20 diabetics (BMI 26.4 ± 2.5, age 56.53 ± 13.29) and 20 neuropathics (BMI 26.8 ± 3.4, age 61.2 ± 7.7). The electrical activity of six muscles was collected bilaterally on the lower limb during gait: gluteus medius, rectus femoris, tibialis anterior, peroneous longus, gastrocnemius lateralis, and extensor digitorum communis. Electromyographic activity was represented through linear envelopes. Time and space parameters were also evaluated by means of two Bertec force plates and a six cameras motion capture system (BTS, 60-120 Hz). At initial contact and loading response, an early peak of rectus femoris activity occurred in diabetic subjects with and without neuropathy. During midstance a delay of gastrocnemius activity was observed in diabetic non-neuropathic subjects. During terminal swing a delay of rectus femoris and gluteus medius activity was seen in diabetic non-neuropathic subjects'. The results suggest that important muscle activity deviations are present in diabetic subjects although these are not directly related to neuropathy. PMID:22098824

Sawacha, Zimi; Spolaor, Fabiola; Guarneri, Gabriella; Contessa, Paola; Carraro, Elena; Venturin, Andrea; Avogaro, Angelo; Cobelli, Claudio

2012-01-01

316

Effect of Resveratrol on Antioxidant Enzyme Activities in the Brain of Healthy Rat  

Microsoft Academic Search

We have studied the effect of resveratrol on lipoperoxidation and antioxidant enzyme activity level in the brain of healthy\\u000a rats. When intraperitoneally administered, resveratrol significantly and dose dependently decreased brain malondialdehyde\\u000a level. Resveratrol also increased in a dose-dependent way brain superoxide dismutase, catalase and peroxidase activities.\\u000a Optimal effect on antioxidant enzyme and lipoperoxidation products were obtained with resveratrol concentration of

Meherzia Mokni; Salem Elkahoui; Ferid Limam; Mohamed Amri; Ezzedine Aouani

2007-01-01

317

Extracting Rhythmic Brain Activity for Brain-Computer Interfacing through Constrained Independent Component Analysis  

PubMed Central

We propose a technique based on independent component analysis (ICA) with constraints, applied to the rhythmic electroencephalographic (EEG) data recorded from a brain-computer interfacing (BCI) system. ICA is a technique that can decompose the recorded EEG into its underlying independent components and in BCI involving motor imagery, the aim is to isolate rhythmic activity over the sensorimotor cortex. We demonstrate that, through the technique of spectrally constrained ICA, we can learn a spatial filter suited to each individual EEG recording. This can effectively extract discriminatory information from two types of single-trial EEG data. Through the use of the ICA algorithm, the classification accuracy is improved by about 25%, on average, compared to the performance on the unpreprocessed data. This implies that this ICA technique can be reliably used to identify and extract BCI-related rhythmic activity underlying the recordings where a particular filter is learned for each subject. The high classification rate and low computational cost make it a promising algorithm for application to an online BCI system. PMID:18354730

Wang, Suogang; James, Christopher J.

2007-01-01

318

Exercise Modulates Redox-Sensitive Small GTPase Activity in the Brain Microvasculature in a Model of Brain Metastasis Formation  

PubMed Central

Tumor cell extravasation into the brain requires passage through the blood-brain barrier (BBB). There is evidence that exercise can alter the oxidation status of the brain microvasculature and protect against tumor cell invasion into the brain, although the mechanisms are not well understood. In the current study, we focused on the role of microenvironment generated by exercise and metastasizing tumor cells at the levels of brain microvessels, influencing oxidative stress-mediated responses and activation of redox-sensitive small GTPases. Mature male mice were exercised for four weeks using a running wheel with the average voluntary running distance 9.0±0.3 km/day. Mice were then infused with 1.0×106 D122 (murine Lewis lung carcinoma) cells into the brain microvasculature, and euthanized either 48 hours (in short-term studies) or 2–3 weeks (in long-term studies) post tumor cell administration. A significant increase in the level of reactive oxygen species was observed following 48 hours or 3 weeks of tumor cells growth, which was accompanied by a reduction in MnSOD expression in the exercised mice. Activation of the small GTPase Rho was negatively correlated with running distance in the tumor cell infused mice. Together, these data suggest that exercise may play a significant role during aggressive metastatic invasion, especially at higher intensities in pre-trained individuals. PMID:24804765

Wolff, Gretchen; Balke, Jordan E.; Andras, Ibolya E.; Park, Minseon; Toborek, Michal

2014-01-01

319

Abnormal blood-group-Ss-active sialoglycoproteins in the membrane of Miltenberger class III, IV and V human erythrocytes.  

PubMed Central

1. We have studied the inherited changes occurring in the sialoglycoproteins of membranes from erythrocytes of type Miltenberger Class III (Mi.III), Miltenberger Class IV (Mi.IV) and Miltenberger Class V (Mi.V) by using sodium dodecyl sulphate/polyacrylamide gel electrophoresis and lactoperoxidase radioiodination. 2. Mi.III erythrocytes lack the normal blood-group-Ss-active sialoglycoprotein but contain an unusual s-active sialoglycoprotein of higher apparent molecular weight. A similar abnormal S-active sialoglycoprotein appears to occur in Mi.IV erythrocytes. 3. The Mi.V condition is associated with the hemizygous absence of both the normal blood-group-MN-active sialoglycoprotein and the normal Ss-active sialoglycorprotein. However, a new sialoglycoprotein component is present in these cells that has properties characteristic of both the MN-active and Ss-active sialoglycoproteins. 4. Our results suggest that the new sialoglycorportein present in Mi.V erythrocytes is a hybrid of the normal MN sialoglycoprotein and an s-active sialoglycoprotein that has properties similar to the s-active sialoglycoprotein found in Mi.III erythrocytes. We suggest that the unusual Mi.V sialoglycoprotein is derived from chromosomal misalignment with unequal crossing-over between the genes for the MN- and Ss-active sialoglycoproteins in a manner similar to that which gives rise to haemoglobin Lepore. 5. Further studies of S-s-erythrocytes confirm that these cells lack normal Ss-active sialoglycoprotein, but contain an unusual component that shows some of the properties of the normal Ss-active sialoglycoprotein. 6. Analysis of erythrocytes of type Mk/Mi.III confirms that, in addition to the known hemizygous lack of the MN-active sialoglycoprotein, the Mk condition is also associated with a loss of the Ss-active sialoglycoprotein. 7. In order to facilitate discussion of the complex changes that occur in these variant erythrocytes, a new unified nomenclature is used for the erythrocyte sialoglycoproteins. Images Fig. 1. Fig. 2. Fig. 4. Fig. 5. Fig. 7. Fig. 9. PMID:230820

Anstee, D J; Mawby, W J; Tanner, M J

1979-01-01

320

Cytokine release syndrome after blinatumomab treatment related to abnormal macrophage activation and ameliorated with cytokine-directed therapy  

PubMed Central

Blinatumomab is a CD19/CD3-bispecific T-cell receptor-engaging (BiTE) antibody with efficacy in refractory B-precursor acute lymphoblastic leukemia. Some patients treated with blinatumomab and other T cell-activating therapies develop cytokine release syndrome (CRS). We hypothesized that patients with more severe toxicity may experience abnormal macrophage activation triggered by the release of cytokines by T-cell receptor–activated cytotoxic T cells engaged by BiTE antibodies and leading to hemophagocytic lymphohistiocytosis (HLH). We prospectively monitored a patient during blinatumomab treatment and observed that he developed HLH. He became ill 36 hours into the infusion with fever, respiratory failure, and circulatory collapse. He developed hyperferritinemia, cytopenias, hypofibrinogenemia, and a cytokine profile diagnostic for HLH. The HLH continued to progress after discontinuation of blinatumomab; however, he had rapid improvement after IL-6 receptor-directed therapy with tocilizumab. Patients treated with T cell-activating therapies, including blinatumomab, should be monitored for HLH, and cytokine-directed therapy may be considered in cases of life-threatening CRS. This trial was registered at www.clinicaltrials.gov as #NCT00103285. PMID:23678006

Rheingold, Susan R.; Maude, Shannon L.; Zugmaier, Gerhard; Barrett, David M.; Seif, Alix E.; Nichols, Kim E.; Suppa, Erica K.; Kalos, Michael; Berg, Robert A.; Fitzgerald, Julie C.; Aplenc, Richard; Gore, Lia; Grupp, Stephan A.

2013-01-01

321

Optical imaging of neural and hemodynamic brain activity  

NASA Astrophysics Data System (ADS)

Optical imaging technologies can be used to record neural and hemodynamic activity. Neural activity elicits physiological changes that alter the optical tissue properties. Specifically, changes in polarized light are concomitant with neural depolarization. We measured polarization changes from an isolated lobster nerve during action potential propagation using both reflected and transmitted light. In transmission mode, polarization changes were largest throughout the center of the nerve, suggesting that most of the optical signal arose from the inner nerve bundle. In reflection mode, polarization changes were largest near the edges, suggesting that most of the optical signal arose from the outer sheath. To overcome irregular cell orientation found in the brain, we measured polarization changes from a nerve tied in a knot. Our results show that neural activation produces polarization changes that can be imaged even without regular cell orientations. Neural activation expends energy resources and elicits metabolic delivery through blood vessel dilation, increasing blood flow and volume. We used spectroscopic imaging techniques combined with electrophysiological measurements to record evoked neural and hemodynamic responses from the auditory cortex of the rat. By using implantable optics, we measured responses across natural wake and sleep states, as well as responses following different amounts of sleep deprivation. During quiet sleep, evoked metabolic responses were larger compared to wake, perhaps because blood vessels were more compliant. When animals were sleep deprived, evoked hemodynamic responses were smaller following longer periods of deprivation. These results suggest that prolonged neural activity through sleep deprivation may diminish vascular compliance as indicated by the blunted vascular response. Subsequent sleep may allow vessels to relax, restoring their ability to deliver blood. These results also suggest that severe sleep deprivation or chronic sleep disturbances could push the vasculature to critical limits, leading to metabolic deficit and the potential for tissue trauma.

Schei, Jennifer Lynn

322

Abnormal Amygdala and Prefrontal Cortex Activation to Facial Expressions in Pediatric Bipolar Disorder  

ERIC Educational Resources Information Center

Objective: Previous functional magnetic resonance imaging (fMRI) studies in pediatric bipolar disorder (BD) have reported greater amygdala and less dorsolateral prefrontal cortex (DLPFC) activation to facial expressions compared to healthy controls. The current study investigates whether these differences are associated with the early or late…

Garrett, Amy S.; Reiss, Allan L.; Howe, Meghan E.; Kelley, Ryan G.; Singh, Manpreet K.; Adleman, Nancy E.; Karchemskiy, Asya; Chang, Kiki D.

2012-01-01

323

Activation of HIF2? in Kidney Proximal Tubule Cells Causes Abnormal Glycogen Deposition but Not Tumorigenesis  

PubMed Central

Renal cell carcinoma (RCC) is the most common primary cancer arising from the kidney in adults, with clear cell carcinoma (ccRCC) representing ~75% of all RCCs. Increased expression of the hypoxia-induced factors HIF1? and HIF2? has been suggested as a pivotal step in ccRCC carcinogenesis, but this has not been thoroughly tested. Here we report that expression of a constitutively activated form of HIF2? (P405A, P530A and N851A, HIF2?M3) in the proximal tubules of mice is not sufficient to promote ccRCC by itself, nor does it enhance HIF1?M3 oncogenesis when co-expressed with constitutively active HIF1?M3. Neoplastic transformation in kidneys was not detected at up to 33 months of age, nor was increased expression of Ki67 (MKI67), ?H2AX (H2AFX) or CD70 observed. Further, the genome-wide transcriptome of the transgenic kidneys does not resemble human ccRCC. We conclude that a constitutively active HIF2? is not sufficient to cause neoplastic transformation of proximal tubules, arguing against the idea that HIF2? activation is critical for ccRCC tumorigenesis. PMID:23447580

Fu, Leiping; Wang, Gang; Shevchuk, Maria M.; Nanus, David M.; Gudas, Lorraine J.

2013-01-01

324

Abnormal fMRI Activation Pattern during Story Listening in Individuals with Down Syndrome  

ERIC Educational Resources Information Center

Down syndrome is characterized by disproportionately severe impairments of speech and language, yet little is known about the neural underpinnings of these deficits. We compared fMRI activation patterns during passive story listening in 9 young adults with Down syndrome and 9 approximately age-matched, typically developing controls. The typically…

Reynolds Losin, Elizabeth A.; Rivera, Susan M.; O'Hare, Elizabeth D.; Sowell, Elizabeth R.; Pinter, Joseph D.

2009-01-01

325

Abnormal behavior of interferon-induced enzymatic activities in an interferon-resistant cell line.  

PubMed Central

Interferon induces two double-stranded RNA-dependent enzymatic activities: an oligoisoadenylate synthetase that converts ATP to ppp(A2'p)n5'A, and a protein phosphokinase. We have explored the level and inducibility of these two enzymes in a human cell line (HEC-1) totally insensitive to both the antiviral and the anticellular actions of interferon. The activities of both enzymes are high in untreated cells and only minor changes occur after treatment with interferon, even at high concentrations. Interferon-treated HEC-1 cells do not contain an inhibitor of the oligoisoadenylate synthetase activity. The products of this HEC-1 oligoisoadenylate synthetase consist mainly of dimers, trimers, and tetramers as found in other cell lines after interferon treatment. The synthetase level is unaffected by treating the cells with anti-interferon antiserum, indicating that the results cannot be explained by a spontaneous low production of interferon by these cells. Furthermore, virus multiplication is not inhibited, even after treatment with interferon. These observations suggest that either the two enzymatic activities do not suffice for the establishment of an antiviral state in vivo or that a regulatory control mechanism, lost in these cells and common for both enzymes, is required for the expression of the antiviral action of interferon. This might explain both the constitutivity of the two enzymes and the interferon resistance observed. Images PMID:6159629

Verhaegen, M; Divizia, M; Vandenbussche, P; Kuwata, T; Content, J

1980-01-01

326

Effects of experimental suppression of active (REM) sleep during early development upon adult brain and behavior in the rat.  

PubMed

In order to test the hypothesis that active sleep (AS) is important for the normal development of the central nervous system, 3 different deprivation methods were applied to male Wistar rat pups during the first month of life. Daily injection of clomipramine from 8 to 21 days of age reduced the high level of AS to less than the adult value throughout most of the experimental period. Administration of clonidine from 8 to 21 days of life induced an almost total suppression of AS. Instrumental deprivation, using the 'pendulum' method, led to a significant (but less severe) AS reduction during 2-4 weeks of postnatal age. Open-field behavior testing in adulthood revealed a higher than normal level of ambulation in all 3 experimental groups. Masculine sexual responses were deficient, due to a low level of both mounts and ejaculations, in both clomipramine- and clonidine-treated animals. Neither passive avoidance learning nor dark preference tests revealed any differences between the experimental and control rats. Sleep observations showed that there was an abnormally high incidence of large myoclonic jerks during AS in both clomipramine- and clonidine-treated rats. Subsequent measurement of regional brain weights showed a significant reduction in the cerebral cortex and medulla oblongata, as compared with the respective control groups, in both the clomipramine- and the clonidine-treated rats. In addition, DNA and protein determination in the affected brain areas showed a proportional reduction in the cortex and in the medulla. These results demonstrate that interference with normal functioning either of AS per se or of specific monoaminergic transmitter systems during early development can produce long-lasting behavioral as well as brain morphological and biochemical abnormalities in later life. PMID:6850353

Mirmiran, M; Scholtens, J; van de Poll, N E; Uylings, H B; van der Gugten, J; Boer, G J

1983-04-01

327

Extensive Individual Differences in Brain Activations Associated with Episodic Retrieval are Reliable Over Time  

Microsoft Academic Search

The localization of brain functions using neuroimaging techniques is commonly dependent on statistical analyses of groups of subjects in order to identify sites of activation, particularly in studies of episodic memory. Exclusive reliance on group analysis may be to the detriment of understanding the true underlying cognitive nature of brain activations. In the present study, we found that the patterns

Michael B. Miller; John Darrell Van Horn; George L. Wolford; Todd C. Handy; Monica Valsangkar-Smyth; Souheil Inati; Scott Grafton; Michael S. Gazzaniga

2002-01-01

328

A Three-Dimensional Statistical Analysis for CBF Activation Studies in Human Brain  

Microsoft Academic Search

SUMMARY Many studies of brain function with positron emission tomography (PET) involve the interpretation of a subtracted PET image, usually the difierence between two images under baseline and stimulation conditions. The purpose of these studies is to see which areas of the brain are activated by the stimulation condition. In many cognitive studies, the activation is so slight that the

K. J. Worsley; A. C. Evans; S. Marrett; P. Neelin

1992-01-01

329

Intrinsic Activity in the Fly Brain Gates Visual Information during Behavioral Choices  

Microsoft Academic Search

The small insect brain is often described as an input\\/output system that executes reflex-like behaviors. It can also initiate neural activity and behaviors intrinsically, seen as spontaneous behaviors, different arousal states and sleep. However, less is known about how intrinsic activity in neural circuits affects sensory information processing in the insect brain and variability in behavior. Here, by simultaneously monitoring

Shiming Tang; Mikko Juusola; Björn Brembs

2010-01-01

330

Brain Fitness Activities and Health among Older Female Senior Center Participants in Montreal, Quebec  

Microsoft Academic Search

This research explores the influence of brain fitness activities on mental and physical health among older women. Data were collected from nine French and English senior centers in Montreal, Quebec. A self-administered survey was used among a sample of women (N = 257) to access brain fitness activities on the health indicators. Multivariate analysis (MANOVA) with post hoc Bonferroni t

Tanya R. Fitzpatrick

2010-01-01

331

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

E-print Network

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

Kanwisher, Nancy

332

Aberrant activation of AMP-activated protein kinase contributes to the abnormal distribution of HuR in amyotrophic lateral sclerosis.  

PubMed

Distorted mRNA metabolism contributes to amyotrophic lateral sclerosis (ALS). The human antigen R (HuR) is a major mRNA stabilizer. We report that abnormal localization of HuR was associated with enhanced AMP-activated protein kinase (AMPK) activity in the motor neurons of ALS patients. Activation of AMPK changed the location of HuR in mouse motor neurons and in a motor neuron cell line via phosphorylation of importin-?1. Stimulation of the A2A adenosine receptor normalized the AMPK-evoked redistribution of HuR. This suggests that aberrant activation of AMPK in motor neurons disrupts the normal distribution of HuR, which might imbalance RNA metabolism and contribute to ALS pathogenesis. PMID:25592834

Liu, Yu-Ju; Lee, Li-Ming; Lai, Hsing-Lin; Chern, Yijuang

2015-02-13

333

Abnormal activation of autophagy-induced crinophagy in Paneth cells from patients with Crohn's disease.  

PubMed

Autophagy-related 16 like-1 (ATG16L-1), immunity-related GTPase-M (IRGM), and nucleotide-binding oligomerization domain-containing 2 (NOD2) regulate autophagy, and variants in these genes have been associated with predisposition to Crohn's disease (CD). However, little is known about the role of autophagy in CD. Intestinal biopsies from untreated pediatric patients with CD, celiac disease, or ulcerative colitis were analyzed by immunohistochemistry and electron microscopy. We observed that autophagy was specifically activated in Paneth cells from patients with CD, independently of mucosal inflammation or disease-associated variants of ATG16L1 or IRGM. In these cells, activation of autophagy was associated with a significant decrease in number of secretory granules and features of crinophagy. These observations might account for the disorganization of secretory granules previously reported in Paneth cells from patients with CD. PMID:22285936

Thachil, Elodie; Hugot, Jean-Pierre; Arbeille, Brigitte; Paris, Régine; Grodet, Alain; Peuchmaur, Michel; Codogno, Patrice; Barreau, Frédérick; Ogier-Denis, Eric; Berrebi, Dominique; Viala, Jérôme

2012-05-01

334

Common idiotypes expressed on human, monoclonal, abnormal immunoglobulins and cryoglobulins with polyreactive autoantibody activities.  

PubMed Central

Several human monoclonal immunoglobulins with the same autoantibody activity have been shown to have cross-reactive idiotypes (CRI). In this study, using polyclonal anti-idiotypic antibodies, we found that 28% of human monoclonal immunoglobulins with polyreactive autoantibody activity from myeloma, Waldenström's macroglobulinaemia and cryoglobulinaemia patients shared common idiotype(s). Furthermore, the latter were expressed on human and murine natural MoAbs (respectively in 12% and 22% of the clones tested) and on human IgG preparations used for therapeutic intravenous injections (IVIg) and which contain natural antibodies. These findings suggest that monoclonal immunoglobulins could arise from the proliferation of a clone that normally produces a natural antibody. The existence of common idiotype(s) between monoclonal immunoglobulins and IVIg could be relevant to the improvement noted after treatment with IVIg in patients suffering from peripheral neuropathies associated with monoclonal gammopathy. PMID:8428386

Barbouche, M R; Guilbert, B; Makni, S; Gorgi, Y; Ayed, K; Avrameas, S

1993-01-01

335

Alterations in regional homogeneity of spontaneous brain activity in late-life subthreshold depression.  

PubMed

The early detection of major depression in elderly individuals who are at risk of developing the disease is of prime importance when it comes to the prevention of geriatric depression. We used resting-state functional magnetic resonance imaging (fMRI) to examine changes in regional homogeneity (ReHo) of spontaneous activity in late-life subthreshold depression (StD), and we evaluated the sensitivity/specificity performance of these changes. Nineteen elderly individuals with StD and 18 elderly controls underwent a resting-state fMRI scan. The ReHo approach was employed to examine whether StD was related to alterations in resting-state neural activity, in the form of abnormal regional synchronization. Receiver operating characteristic curve analysis and the Fisher stepwise discriminant analysis were used to evaluate the sensitivity/specificity characteristics of the ReHo index in discriminating between the StD subjects and normal controls. The results demonstrated that, compared to controls, StD subjects display lower ReHo in the right orbitofrontal cortex (OFC), left dorsolateral prefrontal cortex (DLPFC), left postcentral gyrus (PCG), and left middle frontal and inferior temporal gyri, as well as higher ReHo in the bilateral insula and right DLPFC. The left PCG and the right DLPFC, OFC, and posterior insula, together reported a predictive accuracy of 91.9%. These results suggest that the regional activity coherence was changed in the resting brain of StD subjects, and that these alterations may serve as potential markers for the early detection of StD in late-life depression. PMID:23301035

Ma, Zhenling; Li, Rui; Yu, Jing; He, Yong; Li, Juan

2013-01-01

336

Alterations in Regional Homogeneity of Spontaneous Brain Activity in Late-Life Subthreshold Depression  

PubMed Central

The early detection of major depression in elderly individuals who are at risk of developing the disease is of prime importance when it comes to the prevention of geriatric depression. We used resting-state functional magnetic resonance imaging (fMRI) to examine changes in regional homogeneity (ReHo) of spontaneous activity in late-life subthreshold depression (StD), and we evaluated the sensitivity/specificity performance of these changes. Nineteen elderly individuals with StD and 18 elderly controls underwent a resting-state fMRI scan. The ReHo approach was employed to examine whether StD was related to alterations in resting-state neural activity, in the form of abnormal regional synchronization. Receiver operating characteristic curve analysis and the Fisher stepwise discriminant analysis were used to evaluate the sensitivity/specificity characteristics of the ReHo index in discriminating between the StD subjects and normal controls. The results demonstrated that, compared to controls, StD subjects display lower ReHo in the right orbitofrontal cortex (OFC), left dorsolateral prefrontal cortex (DLPFC), left postcentral gyrus (PCG), and left middle frontal and inferior temporal gyri, as well as higher ReHo in the bilateral insula and right DLPFC. The left PCG and the right DLPFC, OFC, and posterior insula, together reported a predictive accuracy of 91.9%. These results suggest that the regional activity coherence was changed in the resting brain of StD subjects, and that these alterations may serve as potential markers for the early detection of StD in late-life depression. PMID:23301035

Yu, Jing; He, Yong; Li, Juan

2013-01-01

337

Statistical analysis of brain sulci based on active ribbon modeling  

NASA Astrophysics Data System (ADS)

This paper presents a general statistical framework for modeling deformable object. This model is devoted being used in digital brain atlases. We first present a numerical modeling of brain sulci. We present also a method to characterize the high inter-individual variability of basic cortical structures on which the description of the cerebral cortex is based. The aimed applications use numerical modeling of brain sulci to assist non-linear registration of human brains by inter-individual anatomical matching or to better compare neuro-functional recordings performed on a series of individuals. The utilization of these methods is illustrated using a few examples.

Barillot, Christian; Le Goualher, Georges; Hellier, Pierre; Gibaud, Bernard

1999-05-01

338

Automatic classification of squamosal abnormality in micro-CT images for the evaluation of rabbit fetal skull defects using active shape models  

NASA Astrophysics Data System (ADS)

High-throughput micro-CT imaging has been used in our laboratory to evaluate fetal skeletal morphology in developmental toxicology studies. Currently, the volume-rendered skeletal images are visually inspected and observed abnormalities are reported for compounds in development. To improve the efficiency and reduce human error of the evaluation, we implemented a framework to automate the evaluation process. The framework starts by dividing the skull into regions of interest and then measuring various geometrical characteristics. Normal/abnormal classification on the bone segments is performed based on identifying statistical outliers. In pilot experiments using rabbit fetal skulls, the majority of the skeletal abnormalities can be detected successfully in this manner. However, there are shape-based abnormalities that are relatively subtle and thereby difficult to identify using the geometrical features. To address this problem, we introduced a model-based approach and applied this strategy on the squamosal bone. We will provide details on this active shape model (ASM) strategy for the identification of squamosal abnormalities and show that this method improved the sensitivity of detecting squamosal-related abnormalities from 0.48 to 0.92.

Chen, Antong; Dogdas, Belma; Mehta, Saurin; Bagchi, Ansuman; Wise, L. David; Winkelmann, Christopher

2014-03-01

339

Controlled Cortical Impact Traumatic Brain Injury in 3xTg-AD Mice Causes Acute Intra-axonal Amyloid-beta Accumulation and Independently Accelerates the Development of Tau Abnormalities  

PubMed Central

Alzheimer’s disease (AD) is a neurodegenerative disorder characterized pathologically by progressive neuronal loss, extracellular plaques containing the amyloid-? (A?) peptides, and neurofibrillary tangles composed of hyperphosphorylated tau proteins. A? is thought to act upstream of tau, affecting its phosphorylation and therefore aggregation state. One of the major risk factors for AD is traumatic brain injury (TBI). Acute intra-axonal A? and diffuse extracellular plaques occur in approximately 30% of human subjects following severe TBI. Intra-axonal accumulations of tau but not tangle-like pathologies have also been found in these patients. Whether and how these acute accumulations contribute to subsequent AD development is not known, and the interaction between A? and tau in the setting of TBI has not been investigated. Here, we report that controlled cortical impact TBI in 3xTg-AD mice resulted in intra-axonal A? accumulations and increased phospho-tau immunoreactivity at 24 hours and up to 7 days post TBI. Given these findings, we investigated the relationship between A? and tau pathologies following trauma in this model by systemic treatment of Compound E to inhibit ?-secrectase activity, a proteolytic process required for A? production. Compound E treatment successfully blocked post-traumatic A? accumulation in these injured mice at both time points. However, tau pathology was not affected. Our data support a causal role for TBI in acceleration of AD-related pathologies, and suggest that TBI may independently affect A? and tau abnormalities. Future studies will be required to assess the behavioral and long-term neurodegenerative consequences of these pathologies. PMID:21715616

Tran, Hien T; LaFerla, Frank M.; Holtzman, David M.; Brody, David L.

2011-01-01

340

Abnormal functional connectivity density in Parkinson's disease.  

PubMed

The pathology of Parkinson's disease (PD) is not confined to the nigrostriatal pathway, but also involves widespread cerebral cortical areas. Using seed-based resting state functional connectivity, many previous studies have demonstrated that PD patients have abnormal functional integration. However, this technique strongly relies on a priori selection of the seed regions and may miss important unpredictable findings. Using an ultrafast voxel-wise functional connectivity density approach, this study performed a whole brain functional connectivity analysis to investigate the abnormal resting-state functional activities in PD patients. Compared with healthy controls, PD patients exhibited decreased short-range functional connectivity densities in regions that were mainly located in the ventral visual pathway and decreased long-range functional connectivity densities in the right middle and superior frontal gyrus, which have been speculated to be associated with visual hallucinations and cognitive dysfunction, respectively. PD patients also exhibited increased short- and long-range functional connectivity densities in the bilateral precuneus and posterior cingulate cortex, which may represent a compensatory process for maintaining normal brain function. The observed functional connectivity density alterations might be related to the disturbed structural connectivity of PD patients, leading to abnormal functional integration. Our results suggest that functional connectivity density mapping may provide a useful means to assess PD-related neurodegeneration and to study the pathophysiology of PD. PMID:25496782

Zhang, Jiuquan; Bi, Wenwei; Zhang, Yuling; Zhu, Maohu; Zhang, Yanling; Feng, Hua; Wang, Jian; Zhang, Yuanchao; Jiang, Tianzi

2015-03-01

341

Anatomical Abnormalities in Autism?  

PubMed

Substantial controversy exists regarding the presence and significance of anatomical abnormalities in autism spectrum disorders (ASD). The release of the Autism Brain Imaging Data Exchange (?1000 participants, age 6-65 years) offers an unprecedented opportunity to conduct large-scale comparisons of anatomical MRI scans across groups and to resolve many of the outstanding questions. Comprehensive univariate analyses using volumetric, thickness, and surface area measures of over 180 anatomically defined brain areas, revealed significantly larger ventricular volumes, smaller corpus callosum volume (central segment only), and several cortical areas with increased thickness in the ASD group. Previously reported anatomical abnormalities in ASD including larger intracranial volumes, smaller cerebellar volumes, and larger amygdala volumes were not substantiated by the current study. In addition, multivariate classification analyses yielded modest decoding accuracies of individuals' group identity (<60%), suggesting that the examined anatomical measures are of limited diagnostic utility for ASD. While anatomical abnormalities may be present in distinct subgroups of ASD individuals, the current findings show that many previously reported anatomical measures are likely to be of low clinical and scientific significance for understanding ASD neuropathology as a whole in individuals 6-35 years old. PMID:25316335

Haar, Shlomi; Berman, Sigal; Behrmann, Marlene; Dinstein, Ilan

2014-10-14

342

Features of the Diurnal Variations of the Total Electron Content during the Abnormal Low Solar Activity Maximum (2012)  

NASA Astrophysics Data System (ADS)

Based on the GIM (Global Ionospheric Maps) technology we studied the diurnal variations of the global distribution of the total electron content in the quiet helio-geomagnetic conditions during the period of abnormal low solar activity maximum (2012). It was shown that the global distribution of the total electron content reaches the maximum of daily values during spring (autumn) equinox: 60±5 TECU in equatorial latitudes; 35±5 TECU at middle latitudes; 10±5 TECU at high latitudes. There was carried out a comparison of the diurnal variations of the absolute values of the total electron content, which was calculated on the base of the IONEX maps under quiet geomagnetic conditions for different seasons, with variations of the median values of the electron concentration in the ionosphere according to the data from the vertical sounding ionosphere station Almaty. It was shown that in the diurnal variations of the electron concentration in the maximum of the F2 layer of the ionosphere there are observed the same features as in the variations of the total electron content. This paper was written as part of the Kazakhstan Republican program 002 "Applied scientific researches of space activities" under the theme "Develop methods for estimating the crust geomechanical crisis areas using mathematical modeling and satellite technologies".

Mukasheva, Saule; Zhumabayev, Beibit; Toyshiev, Nursultan

343

Physical Activity, Mediterranean Diet and Biomarkers-Assessed Risk of Alzheimer’s: A Multi-Modality Brain Imaging Study  

PubMed Central

Increased physical activity and higher adherence to a Mediterranean-type diet (MeDi) have been independently associated with reduced risk of Alzheimer’s disease (AD). Their association has not been investigated with the use of biomarkers. This study examines whether, among cognitively normal (NL) individuals, those who are less physically active and show lower MeDi adherence have brain biomarker abnormalities consistent with AD. Methods Forty-five NL individuals (age 54 ± 11, 71% women) with complete leisure time physical activity (LTA), dietary information, and cross-sectional 3D T1-weigthed MRI, 11C-Pittsburgh Compound B (PiB) and 18F-fluorodeoxyglucose (FDG) Positron Emission Tomography (PET) scans were examined. Voxel-wise multivariate partial least square (PLS) regression was used to examine the effects of LTA, MeDi and their interaction on brain biomarkers. Age, gender, ethnicity, education, caloric intake, BMI, family history of AD, Apolipoprotein E (APOE) genotype, presence of hypertension and insulin resistance were examined as confounds. Subjects were dichotomized into more and less physically active (LTA+ vs. LTA?; n = 21 vs. 24), and into higher vs. lower MeDi adherence groups (n = 18 vs. 27) using published scoring methods. Spatial patterns of brain biomarkers that represented the optimal association between the images and the groups were generated for all modalities using voxel-wise multivariate Partial Least Squares (PLS) regression. Results Groups were comparable for clinical and neuropsychological measures. Independent effects of LTA and MeDi factors were observed in AD-vulnerable brain regions for all modalities (p < 0.001). Increased AD-burden (in particular higher A? load and lower glucose metabolism) were observed in LTA? compared to LTA+ subjects, and in MeDi? as compared to MeDi+ subjects. A gradient effect was observed for all modalities so that LTA?/MeDi? subjects had the highest and LTA+/MeDi+ subjects had the lowest AD-burden (p < 0.001), although the LTA × MeDi interaction was significant only for FDG measures (p < 0.03). Adjusting for covariates did not attenuate these relationships. Conclusion Lower physical activity and MeDi adherence were associated with increased brain AD-burden among NL individuals, indicating that lifestyle factors may modulate AD risk. Studies with larger samples and longitudinal evaluations are needed to determine the predictive power of the observed associations PMID:25599008

Matthews, Dawn C.; Davies, Michelle; Murray, John; Williams, Schantel; Tsui, Wai H.; Li, Yi; Andrews, Randolph D.; Lukic, Ana; McHugh, Pauline; Vallabhajosula, Shankar; de Leon, Mony J.; Mosconi, Lisa

2014-01-01

344

Selective mutism and abnormal electroencephalography (EEG) tracings.  

PubMed

Epileptic discharges are not considered a part of the clinical picture of selective mutism, and electroencephalography is generally not recommended in its work-up. This report describes 6 children with selective mutism who were found to have a history of epilepsy and abnormal interictal or subclinical electroencephalography recordings. Two of them had benign epilepsy of childhood with centro-temporal spikes. The mutism was not related in time to the presence of active seizures. While seizures could be controlled in all children by medications, the mutism resolved only in 1. Although the discharges could be coincidental, they might represent a co-morbidity of selective mutism or even play a role in its pathogenesis. Selective mutism should be listed among the psychiatric disorders that may be associated with electroencephalographic abnormalities. It can probably be regarded as a symptom of a more complicated organic brain disorder. PMID:21596703

Politi, Keren; Kivity, Sara; Goldberg-Stern, Hadassa; Halevi, Ayelet; Shuper, Avinoam

2011-11-01

345

Perception of Music and Dimensional Complexity of Brain Activity  

Microsoft Academic Search

The non-linear resonance hypothesis of music perception was tested in an experiment comparing a group of musically sophisticated and a group of less sophisticated subjects. The prediction that weakly chaotic music entrains less complex brain wave (EEG) oscillations at the prefrontal cortex was confirmed by using a correlational dimension algorithm. Strongly chaotic (stochastic) and periodic music both stimulated higher brain

N. Birbaumer; W. Lutzenberger; H. Rau; G. Mayer-Kress; I. Choi; C. Braun

1994-01-01

346

Abnormal expression of plasminogen activator inhibitors in patients with gestational trophoblastic disease.  

PubMed

We previously reported significantly elevated levels of plasminogen activator inhibitor type 1 (PAI-1) in plasma and placenta from pregnant women with severe pre-eclampsia, and pre-eclampsia is a frequent problem in molar pregnancies. As increases in PAI-1 may contribute to the placental alterations that occur in pre-eclampsia, we have begun to investigate changes in PAI-1 as well as PAI-2 and several other components of the fibrinolytic system in patients with trophoblastic disease. Significant increases in plasma PAI-1 and decreases in plasma PAI-2 levels were observed in molar pregnancies when compared with the levels in normal pregnant women of similar gestational age. PAI-1 antigen levels also were increased, and PAI-2 levels were decreased in placenta from women with molar pregnancies compared with placenta obtained by spontaneous abortion. Immunohistochemical analysis revealed strong positive and specific staining of PAI-1 in trophoblastic epithelium in molar pregnancies and relatively weak staining of PAI-2. No association between the distribution of PAI-1 and vitronectin was found, and no specific signal for tissue type PA, urokinase type PA, tumor necrosis factor-alpha, or interleukin-1 was detected. In situ hybridization revealed an increase in PAI-1 but not PAI-2 mRNAs in placenta from molar pregnancies in comparison with placenta from abortions. These results demonstrate increased PAI-1 protein and mRNA in trophoblastic disease and suggest that localized elevated levels of PAI-1 may contribute to the hemostatic problems associated with this disorder. PMID:8863672

Estellés, A; Grancha, S; Gilabert, J; Thinnes, T; Chirivella, M; España, F; Aznar, J; Loskutoff, D J

1996-10-01

347

Converging genetic and functional brain imaging evidence links neuronal excitability to working memory, psychiatric disease, and brain activity  

PubMed Central

Summary Working memory, the capacity of actively maintaining task-relevant information during a cognitive task, is a heritable trait. Working memory deficits are characteristic for many psychiatric disorders. We performed genome-wide gene-set enrichment analyses in multiple independent data sets of young and aged cognitively healthy subjects (n = 2’824), and in a large schizophrenia case-control sample (n = 32’143). The voltage-gated cation channel activity gene-set, consisting of genes related to neuronal excitability, was robustly linked to performance in working memory-related tasks across ages, and to schizophrenia. Functional brain imaging in 707 healthy participants linked this gene-set also to working memory-related activity in the parietal cortex and the cerebellum. Gene-set analyses may help to dissect the molecular underpinnings of cognitive dimensions, brain activity and psychopathology. PMID:24529980

Heck, A.; Fastenrath, M.; Ackermann, S.; Auschra, B.; Bickel, H.; Coynel, D.; Gschwind, L.; Jessen, F.; Kaduszkiewicz, H.; Maier, W.; Milnik, A.; Pentzek, M.; Riedel-Heller, S.G.; Ripke, S.; Spalek, K.; Sullivan, P.; Vogler, C.; Wagner, M.; Weyerer, S.; Wolfsgruber, S.; de Quervain, D.; Papassotiropoulos, A.

2014-01-01

348

Test-Retest Reliability of fMRI Brain Activity during Memory Encoding  

PubMed Central

The mechanisms underlying hemispheric specialization of memory are not completely understood. Functional magnetic resonance imaging (fMRI) can be used to develop and test models of hemispheric specialization. In particular for memory tasks however, the interpretation of fMRI results is often hampered by the low reliability of the data. In the present study we therefore analyzed the test-retest reliability of fMRI brain activation related to an implicit memory encoding task, with a particular focus on brain activity of the medial temporal lobe (MTL). Fifteen healthy subjects were scanned with fMRI on two sessions (average retest interval 35?days) using a commonly applied novelty encoding paradigm contrasting known and unknown stimuli. To assess brain lateralization, we used three different stimuli classes that differed in their verbalizability (words, scenes, fractals). Test-retest reliability of fMRI brain activation was assessed by an intraclass-correlation coefficient (ICC), describing the stability of inter-individual differences in the brain activation magnitude over time. We found as expected a left-lateralized brain activation network for the words paradigm, a bilateral network for the scenes paradigm, and predominantly right-hemispheric brain activation for the fractals paradigm. Although these networks were consistently activated in both sessions on the group level, across-subject reliabilities were only poor to fair (ICCs???0.45). Overall, the highest ICC values were obtained for the scenes paradigm, but only in strongly activated brain regions. In particular the reliability of brain activity of the MTL was poor for all paradigms. In conclusion, for novelty encoding paradigms the interpretation of fMRI results on a single subject level is hampered by its low reliability. More studies are needed to optimize the retest reliability of fMRI activation for memory tasks. PMID:24367338

Brandt, David J.; Sommer, Jens; Krach, Sören; Bedenbender, Johannes; Kircher, Tilo; Paulus, Frieder M.; Jansen, Andreas

2013-01-01

349

Todd, Faraday, and the electrical basis of brain activity.  

PubMed

Robert Bentley Todd (1809-60) was the UK's first eminent neurologist and neuroscientist. An anatomist, physiologist, and clinical scientist with an interest in the nervous system, he was the first to confirm the electrical basis of brain activity in the 1840s. He was influenced by his contemporary, Michael Faraday at the Royal Institution, and by two colleagues at King's College, John Daniell and Charles Wheatstone, who were also working at the cutting edge of electrical science. Todd conceived of nervous polarity (force) generated in nervous centres and compared this with the polar force of voltaic electricity developed in the galvanic battery. He brilliantly foresaw each nerve vesicle (cell) and its related fibres (ie, neuron) as a distinct apparatus for the development and transmission of nervous polarity. Epilepsy was the result of periodic unnatural development of nervous force leading to the "disruptive discharge" described by Faraday. Faraday, who studied animal electricity in the Gymnotus (electric eel), and Todd saw nervous polarity as a higher form of interchangeable energy. PMID:15324724

Reynolds, Edward H

2004-09-01

350

Development of modularity in the neural activity of children's brains.  

PubMed

We study how modularity of the human brain changes as children develop into adults. Theory suggests that modularity can enhance the response function of a networked system subject to changing external stimuli. Thus, greater cognitive performance might be achieved for more modular neural activity, and modularity might likely increase as children develop. The value of modularity calculated from functional magnetic resonance imaging (fMRI) data is observed to increase during childhood development and peak in young adulthood. Head motion is deconvolved from the fMRI data, and it is shown that the dependence of modularity on age is independent of the magnitude of head motion. A model is presented to illustrate how modularity can provide greater cognitive performance at short times, i.e. task switching. A fitness function is extracted from the model. Quasispecies theory is used to predict how the average modularity evolves with age, illustrating the increase of modularity during development from children to adults that arises from selection for rapid cognitive function in young adults. Experiments exploring the effect of modularity on cognitive performance are suggested. Modularity may be a potential biomarker for injury, rehabilitation, or disease. PMID:25619207

Chen, Man; Deem, Michael W

2015-01-01

351

Brain activity during driving with distraction: an immersive fMRI study  

PubMed Central

Introduction: Non-invasive measurements of brain activity have an important role to play in understanding driving ability. The current study aimed to identify the neural underpinnings of human driving behavior by visualizing the areas of the brain involved in driving under different levels of demand, such as driving while distracted or making left turns at busy intersections. Materials and Methods: To capture brain activity during driving, we placed a driving simulator with a fully functional steering wheel and pedals in a 3.0 Tesla functional magnetic resonance imaging (fMRI) system. To identify the brain areas involved while performing different real-world driving maneuvers, participants completed tasks ranging from simple (right turns) to more complex (left turns at busy intersections). To assess the effects of driving while distracted, participants were asked to perform an auditory task while driving analogous to speaking on a hands-free device and driving. Results: A widely distributed brain network was identified, especially when making left turns at busy intersections compared to more simple driving tasks. During distracted driving, brain activation shifted dramatically from the posterior, visual and spatial areas to the prefrontal cortex. Conclusions: Our findings suggest that the distracted brain sacrificed areas in the posterior brain important for visual attention and alertness to recruit enough brain resources to perform a secondary, cognitive task. The present findings offer important new insights into the scientific understanding of the neuro-cognitive mechanisms of driving behavior and lay down an important foundation for future clinical research. PMID:23450757

Schweizer, Tom A.; Kan, Karen; Hung, Yuwen; Tam, Fred; Naglie, Gary; Graham, Simon J.

2013-01-01

352

Long-term recovery from hippocampal-related behavioral and biochemical abnormalities induced by noise exposure during brain development. Evaluation of auditory pathway integrity.  

PubMed

Sound is an important part of man's contact with the environment and has served as critical means for survival throughout his evolution. As a result of exposure to noise, physiological functions such as those involving structures of the auditory and non-auditory systems might be damaged. We have previously reported that noise-exposed developing rats elicited hippocampal-related histological, biochemical and behavioral changes. However, no data about the time lapse of these changes were reported. Moreover, measurements of auditory pathway function were not performed in exposed animals. Therefore, with the present work, we aim to test the onset and the persistence of the different extra-auditory abnormalities observed in noise-exposed rats and to evaluate auditory pathway integrity. Male Wistar rats of 15 days were exposed to moderate noise levels (95-97 dB SPL, 2 h a day) during one day (acute noise exposure, ANE) or during 15 days (sub-acute noise exposure, SANE). Hippocampal biochemical determinations as well as short (ST) and long term (LT) behavioral assessments were performed. In addition, histological and functional evaluations of the auditory pathway were carried out in exposed animals. Our results show that hippocampal-related behavioral and biochemical changes (impairments in habituation, recognition and associative memories as well as distortion of anxiety-related behavior, decreases in reactive oxygen species (ROS) levels and increases in antioxidant enzymes activities) induced by noise exposure were almost completely restored by PND 90. In addition, auditory evaluation shows that increased cochlear thresholds observed in exposed rats were re-established at PND 90, although with a remarkable supra-threshold amplitude reduction. These data suggest that noise-induced hippocampal and auditory-related alterations are mostly transient and that the effects of noise on the hippocampus might be, at least in part, mediated by the damage on the auditory pathway. However, we cannot exclude that a different mechanism might be responsible for the observed hippocampal-related changes. PMID:24911434

Uran, S L; Gómez-Casati, M E; Guelman, L R

2014-10-01

353

Resting brain activity varies with dream recall frequency between subjects.  

PubMed

Dreaming is still poorly understood. Notably, its cerebral underpinning remains unclear. Neuropsychological studies have shown that lesions in the temporoparietal junction (TPJ) and/or the white matter of the medial prefrontal cortex (MPFC) lead to the global cessation of dream reports, suggesting that these regions of the default mode network have key roles in the dreaming process (forebrain 'dream-on' hypothesis). To test this hypothesis, we measured regional cerebral blood flow (rCBF) using [(15)O]H2O positron emission tomography in healthy subjects with high and low dream recall frequencies (DRFs) during wakefulness (rest) and sleep (rapid eye movement (REM) sleep, N2, and N3). Compared with Low recallers (0.5 ± 0.3 dream recall per week in average), High recallers (5.2 ± 1.4) showed higher rCBF in the TPJ during REM sleep, N3, and wakefulness, and in the MPFC during REM sleep and wakefulness. We demonstrate that the resting states of High recallers and Low recallers differ during sleep and wakefulness. It coheres with previous ERP results and confirms that a high/low DRF is associated with a specific functional organization of the brain. These results support the forebrain 'dream-on' hypothesis and suggest that TPJ and MPFC are not only involved in dream recall during wakefulness but also have a role in dreaming during sleep (production and/or encoding). Increased activity in the TPJ and MPFC might promote the mental imagery and/or memory encoding of dreams. Notably, increased activity in TPJ might facilitate attention orienting toward external stimuli and promote intrasleep wakefulness, facilitating the encoding of the dreams in memory. PMID:24549103

Eichenlaub, Jean-Baptiste; Nicolas, Alain; Daltrozzo, Jérôme; Redouté, Jérôme; Costes, Nicolas; Ruby, Perrine

2014-06-01

354

Cocaine is pharmacologically active in the nonhuman primate fetal brain  

PubMed Central

Cocaine use during pregnancy is deleterious to the newborn child, in part via its disruption of placental blood flow. However, the extent to which cocaine can affect the function of the fetal primate brain is still an unresolved question. Here we used PET and MRI and show that in third-trimester pregnant nonhuman primates, cocaine at doses typically used by drug abusers significantly increased brain glucose metabolism to the same extent in the mother as in the fetus (?100%). Inasmuch as brain glucose metabolism is a sensitive marker of brain function, the current findings provide evidence that cocaine use by a pregnant mother will also affect the function of the fetal brain. We are also unique in showing that cocaine’s effects in brain glucose metabolism differed in pregnant (increased) and nonpregnant (decreased) animals, which suggests that the psychoactive effects of cocaine are influenced by the state of pregnancy. Our findings have clinical implications because they imply that the adverse effects of prenatal cocaine exposure to the newborn child include not only cocaine’s deleterious effects to the placental circulation, but also cocaine’s direct pharmacological effect to the developing fetal brain. PMID:20080687

Benveniste, Helene; Fowler, Joanna S.; Rooney, William D.; Scharf, Bruce A.; Backus, W. Walter; Izrailtyan, Igor; Knudsen, Gitte M.; Hasselbalch, Steen G.; Volkow, Nora D.

2010-01-01

355

PET with F-18 fluorodeoxyglucose measures of local brain activity and memory in schizophrenia and in depression  

SciTech Connect

Positron emission tomography with (F-18) fluorodeoxyglucose (FDG) scan has provided non-invasive measures of regional cerebral glucose utilization which are directly related with levels of functional activity in regions of the brain. The FDG technique was applied to the study of brain activity thought to be impaired in 6 chronic schizophrenics (SCH) and 6 depressed (D) patients in comparison with 6 healthy age-matched controls (C). Local cerebral metabolic rates of glucose utilization LCMRglc were determined for 8 regions in both left and right hemispheres and were expressed in reference to a person's mean CMRglc. Multivariate comparisons of the 16 measures showed no significant differences between the 3 groups; follow-up step-down analyses and t-tests failed to specify any regional or global LCMRglc reliable to separate patients from controls. They also did not differ in any of 18 multidimensional tests of memory and decision, except for lower delayed verbal recall in D patients. When both SCH and D were classified into those with CT large and those with CT small ventricles, there were no multivariate differences. Only partial LCMRglc separated large from small ventricle patients (F(1,7) = 6.12, p<0.042), but finding no multivariate significance makes this result questionable. The ventricular grouping of SCH alone may reveal a marginal difference in global CMRglc t(4) = 2.58, p<0.06, given a larger patient sample. In contrast to recent reports, indices to brain activity in schizophrenic and depressed patients do not seem to be abnormal.

Riege, W.H.; Metter, E.J.; Kuhl, D.E.; Phelps, M.E.; Kling, A.

1984-01-01

356

Abnormal metabolism of arachidonic acid in chronic inflammatory bowel disease: enhanced release of leucotriene B4 from activated neutrophils.  

PubMed Central

The metabolism of endogenous arachidonic acid P(AA) was investigated in activated neutrophils from 20 patients with Crohn's disease, 20 with ulcerative colitis, and 25 healthy volunteers. 1-14C-P(AA) was incorporated into intracellular pools of phospholipids prior to activation of the cells with ionophore A23187 and analyses of released arachidonic acid metabolites by thin layer chromatography. Total release of radioactivity expressing the release of arachidonic acid and its metabolites, was equal in the experimental and control groups, which suggests a normal substrate availability. In contrast, there was a marked increase in the relative release of leucotriene B4 (LTB4) and its omega-oxidation products, 20-hydroxy-LTB4 (20-OH-LTB4) and 20-carboxy-LTB4 (20-COOH-LTB4), with LTB4 values exceeding the reference interval in seven of 20 patients with Crohn's disease, median 8.7%, and in six of 20 patients with ulcerative colitis, median 7.7%, as compared with a median of 5.3% in healthy volunteers. Furthermore, a decreased release of unmetabolised arachidonic acid, correlating inversely with the release of LTB4 in all experimental and control groups, and normal values for the production of other metabolites of arachidonic acid--for example, 5-hydroxyeicosatetraenoic acid (5-HETE) and 12-hydroxyheptadecatrienoic acid (HHT), point to an enzymatic abnormality such as increased activity of leucotriene B synthetase. An increased capacity for release of LTB4, the major pro-inflammatory metabolite of arachidonic acid lipoxygenation by polymorphonuclear leucocytes, may contribute to perpetuation of the inflammation and to tissue destruction in chronic inflammatory bowel disease. Our findings agree with previous reports of an increased release of LTB4 by the colonic mucosa in this condition. PMID:3030903

Nielsen, O H; Ahnfelt-Rønne, I; Elmgreen, J

1987-01-01

357

The viral theory of schizophrenia revisited: abnormal placental gene expression and structural changes with lack of evidence for H1N1 viral presence in placentae of infected mice or brains of exposed offspring.  

PubMed

Researchers have long noted an excess of patients with schizophrenia were born during the months of January and March. This winter birth effect has been hypothesized to result either from various causes such as vitamin D deficiency (McGrath, 1999; McGrath et al., 2010), or from maternal infection during pregnancy. Infection with a number of viruses during pregnancy including influenza, and rubella are known to increase the risk of schizophrenia in the offspring (Brown, 2006). Animal models using influenza virus or Poly I:C, a viral mimic, have been able to replicate many of the brain morphological, genetic, and behavioral deficits of schizophrenia (Meyer et al., 2006, 2008a, 2009; Bitanihirwe et al., 2010; Meyer and Feldon, 2010; Short et al., 2010). Using a murine model of prenatal viral infection, our laboratory has shown that viral infection on embryonic days 9, 16, and 18 leads to abnormal expression of brain genes and brain structural abnormalities in the exposed offspring (Fatemi et al., 2005, 2008a,b, 2009a,b). The purpose of the current study was to examine gene expression and morphological changes in the placenta, hippocampus, and prefrontal cortex as a result of viral infection on embryonic day 7 of pregnancy. Pregnant mice were either infected with influenza virus [A/WSN/33 strain (H1N1)] or sham-infected with vehicle solution. At E16, placentas were harvested and prepared for either microarray analysis or for light microscopy. We observed significant, upregulation of 77 genes and significant downregulation of 93 genes in placentas. In brains of exposed offspring following E7 infection, there were changes in gene expression in prefrontal cortex (6 upregulated and 24 downregulated at P0; 5 upregulated and 14 downregulated at P56) and hippocampus (4 upregulated and 6 downregulated at P0; 6 upregulated and 13 downregulated at P56). QRT-PCR verified the direction and magnitude of change for a number of genes associated with hypoxia, inflammation, schizophrenia, and autism. Placentas from infected mice showed a number of morphological abnormalities including presence of thrombi and increased presence of immune cells. Additionally, we searched for presence of H1N1 viral-specific genes for M1/M2, NA, and NS1 in placentas of infected mice and brains of exposed offspring and found none. Our results demonstrate that prenatal viral infection disrupts structure and gene expression of the placenta, hippocampus, and prefrontal cortex potentially explaining deleterious effects in the exposed offspring without evidence for presence of viral RNAs in the target tissues. PMID:21277874

Fatemi, S Hossein; Folsom, Timothy D; Rooney, Robert J; Mori, Susumu; Kornfield, Tess E; Reutiman, Teri J; Kneeland, Rachel E; Liesch, Stephanie B; Hua, Kegang; Hsu, John; Patel, Divyen H

2012-03-01

358

Activation of brain endothelial cells by interleukin-1 is regulated by the extracellular matrix after acute brain injury.  

PubMed

The extracellular matrix (ECM) of the central nervous system (CNS) is essential for normal brain function, whilst ECM remodelling is associated with cerebrovascular inflammation driven by the cytokine interleukin-1 (IL-1) after acute brain injury. The effect of ECM remodelling on endothelial activation during neuroinflammation remains unknown. Here we report that ECM remodelling in the cerebrovasculature critically regulates IL-1-induced endothelial cell activation after cerebral ischaemia; Expression levels of ECM molecules associated with the cerebrovasculature, namely fibronectin (FN) and collagen IV (Col IV), strongly increased in brain blood vessels after middle cerebral artery occlusion (MCAo) in a time-dependent manner, reaching a peak of vascular expression 48 h after MCAo. In cultures, FN and Col IV (but also laminin-1 and fibrillin-1) promoted strong attachment of the GPNT endothelial cell line and primary rat brain endothelial cells, which was markedly inhibited by RGD (Arg-Gly-Asp) peptide, or specific integrin ?1, ?4, ?5 and ?v blockade. IL-1?-induced activation of extracellular-regulated kinase 1/2 (ERK1/2) and nuclear factor ?B (NF?B), and synthesis of cytokine-induced neutrophil chemoattractant (CINC-1) were enhanced in cells plated onto ECM molecules, and these responses were inhibited by selective integrin blockade. Finally, increased ECM expression in vessels after MCAo was found associated with vinculin clustering, increased integrin ?1 expression, and increased IL-1 receptor associated kinase-1 (IRAK-1) activity in endothelial cells and perivascular astrocytes. Therefore, our data indicate a novel function for the ECM in the regulation of cerebrovascular inflammation triggered by IL-1 during acute brain injury. PMID:24161715

Summers, Lauren; Kangwantas, Korakoch; Rodriguez-Grande, Beatriz; Denes, Adam; Penny, Jeffrey; Kielty, Cay; Pinteaux, Emmanuel

2013-11-01

359

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

E-print Network

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

Apkarian, A. Vania

360

Two-photon microscopy to measure blood flow and concurrent brain cell activity  

E-print Network

: Blood flow in the brain Corresponding author: Dr. David Kleinfeld Department of Physics University to measure blood flow and concurrent brain cell activity Andy Y. Shih1 , Jonathan D. Driscoll1 , Michael J. Pesavento1 and David Kleinfeld1,2 1 Department of Physics, Division of Physical Sciences, University

Kleinfeld, David

361

Composition and On Demand Deployment of Distributed Brain Activity Analysis Application on Global Grids  

Microsoft Academic Search

The distribution of knowledge (by scientists) and data sources (advanced scientific instruments), and the need of large-scale computational resources for analyzing massive scientific data are two major problems commonly observed in scientific disciplines. The two popular scientific disciplines of this nature are brain science and high-energy physics. The analysis of brain activity data gathered from the MEG (Magnetoencephalography) instrument is

R. Buyya; S. Date; Y. Mizuno-Matsumoto; S. Venugopal; D. Abramson

362

Neuromagnetic localization of rhythmic activity in the human brain: a comparison of three methods  

E-print Network

Neuromagnetic localization of rhythmic activity in the human brain: a comparison of three methods M. Liljestrfm,* J. Kujala, O. Jensen,1 and R. Salmelin Brain Research Unit, Low Temperature Laboratory, Helsinki appropriate subsets of sensors have been selected. MCEFD provides simultaneous localization of sources

Jensen, Ole

363

Brain activity associated with translation from a visual to a symbolic representation in algebra and geometry.  

PubMed

This paper presents a small part of a larger interdisciplinary study that investigates brain activity (using event related potential methodology) of male adolescents when solving mathematical problems of different types. The study design links mathematics education research with neurocognitive studies. In this paper we performed a comparative analysis of brain activity associated with the translation from visual to symbolic representations of mathematical objects in algebra and geometry. Algebraic tasks require translation from graphical to symbolic representation of a function, whereas tasks in geometry require translation from a drawing of a geometric figure to a symbolic representation of its property. The findings demonstrate that electrical activity associated with the performance of geometrical tasks is stronger than that associated with solving algebraic tasks. Additionally, we found different scalp topography of the brain activity associated with algebraic and geometric tasks. Based on these results, we argue that problem solving in algebra and geometry is associated with different patterns of brain activity. PMID:24738538

Leikin, Mark; Waisman, Ilana; Shaul, Shelley; Leikin, Roza

2014-03-01

364

Abnormal functional connectivity in autism spectrum disorders during face processing  

Microsoft Academic Search

Abnormalities in the interactions between functionally linked brain regions have been suggested to be asso- ciated with the clinical impairments observed in autism spectrum disorders (ASD). We investigated functional connectivity within the limbic system during face identification; a primary component of social cognition, in 19 high-functioning adults with ASD and 21 age-and IQ-matched control adults. Activation during identification of previously

Natalia M. Kleinhans; Todd Richards; Lindsey Sterling; Keith C. Stegbauer; Roderick Mahurin; L. Clark Johnson; Jessica Greenson; Geraldine Dawson; Elizabeth Aylward

2008-01-01

365

Acute Effects of Cocaine on Human Brain Activity and Emotion  

Microsoft Academic Search

We investigated brain circuitry mediating cocaine- induced euphoria and craving using functional MRI (fMRI). During double-blind cocaine (0.6 mg\\/kg) and saline infusions in cocaine-dependent subjects, the entire brain was imaged for 5 min before and 13 min after infusion while subjects rated scales for rush, high, low, and craving. Cocaine induced focal signal increases in nucleus accumbens\\/subcallosal cortex (NAc\\/SCC), caudate,

Hans C Breiter; Randy L Gollub; Robert M Weisskoff; David N Kennedy; Nikos Makris; Joshua D Berke; Julie M Goodman; Howard L Kantor; David R Gastfriend; Jonn P Riorden; R. Thomas Mathew; Bruce R Rosen; Steven E Hyman

1997-01-01

366

Measurable benefits on brain activity from the practice of educational leisure  

PubMed Central

Even if behavioral studies relate leisure practices to the preservation of memory in old persons, there is unsubstantial evidence of the import of leisure on brain activity. Aim: This study was to compare the brain activity of elderly retired people who engage in different types of leisure activities. Methods: Quasi-experimental study over a sample of 60 elderly, retired subjects distributed into three groups according to the leisure activities they practised: educational leisure (G1), memory games (G2), and card games (G3). Applied measures include the conceptual distinction between free time and leisure, the test of the organization of free time measuring 24 clock divisions, and EEG register during 12 word list memorizing. Results: The results show that the type of leisure activity is associated with significant quantitative differences regarding the use of free time. G1 devotes more time to leisure activities than G2 (p = 0.007) and G3 (p = 0.034). G1 rests more actively than the other two groups (p = 0.001). The electrical localization of brain activity indicated a reverse tendency of activation according to the bands and groups. Discussion: Engaging in educational leisure activities is a useful practice to protect healthy brain compensation strategies. Future longitudinal research may verify the causal relation between practicing educational leisure activities and functional brain aging. PMID:24653699

Requena, Carmen; López, Verónica

2014-01-01

367

Spatiotemporal Dissociation of Brain Activity Underlying Subjective Awareness, Objective Performance and Confidence  

PubMed Central

Despite intense recent research, the neural correlates of conscious visual perception remain elusive. The most established paradigm for studying brain mechanisms underlying conscious perception is to keep the physical sensory inputs constant and identify brain activities that correlate with the changing content of conscious awareness. However, such a contrast based on conscious content alone would not only reveal brain activities directly contributing to conscious perception, but also include brain activities that precede or follow it. To address this issue, we devised a paradigm whereby we collected, trial-by-trial, measures of objective performance, subjective awareness, and the confidence level of subjective awareness. Using magnetoencephalography recordings in healthy human volunteers, we dissociated brain activities underlying these different cognitive phenomena. Our results provide strong evidence that widely distributed slow cortical potentials (SCPs) correlate with subjective awareness, even after the effects of objective performance and confidence were both removed. The SCP correlate of conscious perception manifests strongly in its waveform, phase, and power. In contrast, objective performance and confidence were both contributed by relatively transient brain activity. These results shed new light on the brain mechanisms of conscious, unconscious, and metacognitive processing. PMID:24647958

Li, Qi; Hill, Zachary

2014-01-01

368

Are capecitabine and the active metabolite 5-fu CNS penetrable to treat breast cancer brain metastasis?  

PubMed

Brain metastasis (BM) is increasingly diagnosed in Her2 positive breast cancer (BC) patients. Lack of effective treatment to breast cancer brain metastases (BCBMs) is probably due to inability of the current therapeutic agents to cross the blood-brain barrier. The central nervous system (CNS) response rate in BCBM patients was reported to improve from 2.6%-6% (lapatinib) to 20%-65% (lapatinib in combination with capecitabine). Lapatinib is a poor brain penetrant. In this study, we evaluated the CNS penetration of capecitabine and hoped to interpret the mechanism of the improved CNS response from the pharmacokinetic (PK) perspective. Capecitabine does not have antiproliferative activity and 5-fluorouracil (5-FU) is the active metabolite. Capecitabine was orally administered to mouse returning an unbound brain-to-blood ratio (Kp,uu,brain) at 0.13 and cerebrospinal fluid (CSF)-to-unbound blood ratio (Kp,uu,CSF) at 0.29 for 5-FU. Neither free brain nor CSF concentration of 5-FU can achieve antiproliferative concentration for 50% of maximal inhibition of cell proliferation of 4.57 µM. BCBM mice were treated with capecitabine monotherapy or in combination with lapatinib. The Kp,uu,brain value of 5-FU increased to 0.17 in the brain tumor in the presence of lapatinib, which is still far below unity. The calculated free concentration of 5-FU and lapatinib in the brain tumor did not reach the antiproliferative potency and neither treatment showed antitumor activity in the BCBM mice. The CNS penetration of 5-FU in human was predicted based on the penetration in preclinical brain tumor, CSF, and human PK and the predicted free CNS concentration was below the antiproliferative potency. These results suggest that CNS penetration of 5-FU and lapatinib are not desirable and development of a true CNS penetrable therapeutic agent will further improve the response rate for BCBM. PMID:25547867

Zhang, Jinqiang; Zhang, Lingli; Yan, Yumei; Li, Shaorong; Xie, Liang; Zhong, Wei; Lv, Jing; Zhang, Xiuhua; Bai, Yu; Cheng, Ziqiang

2015-03-01

369

Photoacoustic imaging to detect rat brain activation after cocaine hydrochloride injection  

NASA Astrophysics Data System (ADS)

Photoacoustic imaging (PAI) was employed to detect small animal brain activation after the administration of cocaine hydrochloride. Sprague Dawley rats were injected with different concentrations (2.5, 3.0, and 5.0 mg per kg body) of cocaine hydrochloride in saline solution through tail veins. The brain functional response to the injection was monitored by photoacoustic tomography (PAT) system with horizontal scanning of cerebral cortex of rat brain. Photoacoustic microscopy (PAM) was also used for coronal view images. The modified PAT system used multiple ultrasonic detectors to reduce the scanning time and maintain a good signal-to-noise ratio (SNR). The measured photoacoustic signal changes confirmed that cocaine hydrochloride injection excited high blood volume in brain. This result shows PAI can be used to monitor drug abuse-induced brain activation.

Jo, Janggun; Yang, Xinmai

2011-03-01

370

Neurobiology of Aging xxx (2006) xxxxxx Age-related changes in brain activation during  

E-print Network

Neurobiology of Aging xxx (2006) xxx­xxx Age-related changes in brain activation during a delayed. / Neurobiology of Aging xxx (2006) xxx­xxx impairment in several different memory variables [78], including WM [9

371

Neural activity and diurnal variation of cortisol: Evidence from brain electrical tomography analysis and  

E-print Network

Neural activity and diurnal variation of cortisol: Evidence from brain electrical tomography tomography was used to compute intracerebral cur- rent density. For the control group, voxelwise analyses, Stress, Prefrontal cortex, Low resolution electro- magnetic tomography (LORETA) In recent years

Wisconsin at Madison, University of

372

Melanoma Brain Metastases: An Unmet Challenge in the Era of Active Therapy  

PubMed Central

Metastatic disease to the brain is a frequent manifestation of melanoma and is associated with significant morbidity, mortality, and poor prognosis. Surgery and stereotactic radiosurgery provide local control but less frequently affect the overall outcome of melanoma brain metastases (MBM). The role of systemic therapies for active brain lesions has been largely under-investigated and those patients are excluded from the vast majority of clinical trials. The advent of active systemic therapy has revolutionized the care of melanoma patients but this benefit has not been systematically translated into intracranial activity. In this article, we review the biology and clinical outcomes of patients with MBM, the evidence supporting the use of radiation, surgery, and systemic therapy in MBM. Prospective studies that included patients with active MBM have shown clinical intracranial activity that parallels systemic activity and support the inclusion of patients with active MBM in clinical trials involving novel agents and combination therapies. PMID:23954973

Gorantla, Vikram; Kirkwood, John M.; Tawbi, Hussein A.

2013-01-01

373

Evaluation of Brain Activity Related to Speech and Handwriting Using NIRS  

NASA Astrophysics Data System (ADS)

The difference by the brain activity when writing it down speech the use of the near-infrared spectroscopy is examined in the present study. It is thought that it becomes a help of the communications between the nurse and people requiring long-term care if the identification of the information transmission means can be evaluated and be detected from the brain activity. Because the possibility of the evaluation of result, “Speech”, and “Writing” was shown, it reports.

Asano, Hirotoshi; Suzuki, Hiroaki; Ide, Hideto

374

Chronic lithium downregulates cyclooxygenase-2 activity and prostaglandin E2 concentration in rat brain  

Microsoft Academic Search

Rats treated with lithium chloride for 6 weeks have been reported to demonstrate reduced turnover of arachidonic acid (AA) in brain phospholipids, and decreases in mRNA and protein levels, and enzyme activity, of AA-selective cytosolic phospholipase A2(cPLA2). We now report that chronic lithium administration to rats significantly reduced the brain protein level and enzyme activity of cyclooxygenase-2 (COX-2), without affecting

F Bosetti; J Rintala; R Seemann; T A Rosenberger; M A Contreras; S I Rapoport; M C Chang

2002-01-01

375

Activity-related quality of life in rehabilitation and traumatic brain injury  

Microsoft Academic Search

Johnston MV, Miklos CS. Activity-related quality of life in rehabilitation and traumatic brain injury. Arch Phys Med Rehabil 2002;83 Suppl 2:S26-38. Objectives: To review approaches to assessment of quality of life (QOL) outcomes in rehabilitation, focusing particularly on traumatic brain injury (TBI), and to introduce the concept of activity-related QOL. Data Sources: A conceptual review, based on extensive searches of

Mark V. Johnston; Carol S. Miklos

2002-01-01

376

Neuroscience Instrumentation and Distributed Analysis of Brain Activity Data: A Case for eScience on Global Grids  

E-print Network

1 Neuroscience Instrumentation and Distributed Analysis of Brain Activity Data: A Case for e commonly observed in scientific disciplines. Two popular scientific disciplines of this nature are brain science and high-energy physics. The analysis of brain activity data gathered from the MEG

Buyya, Rajkumar

377

Altered baseline brain activities before food intake in obese men: A resting state fMRI study.  

PubMed

Obesity as a chronic disease has become a global epidemic. However, why obese individuals eat more still remains unclear. Recent functional neuroimaging studies have found abnormal brain activations in obese people. In the present study, we used resting state functional MRI to observe spontaneous blood-oxygen-level dependent (BOLD) signal fluctuations during both hunger and satiety states in 20 lean and 20 obese men. Using a regional homogeneity (ReHo) analysis method, we measured temporal homogeneity of the regional BOLD signals. We found that, before food intake, obese men had significantly increased synchronicity of activity in the left putamen relative to lean men. Decreased synchronicity of activity was found in the orbitofrontal cortex (OFC) and medial prefrontal cortex(MPFC) in the obese subjects. And, the ratings of hunger of the obese subjects were higher than those of the lean subjects before food intake. After food intake, we did not find the significant differences between the obese men and the lean men. In all participations, synchronicity of activity increased from the fasted to the satiated state in the OFC. The results indicated that OFC plays an important role in feeding behavior, and OFC signaling may be disordered in obesity. Obese men show less inhibitory control during fasting state. This study has provided strong evidence supporting the hypothesis that there is a hypo-functioning reward circuitry in obese individuals, in which the frontal cortex may fail to inhibit the striatum, and consequently lead to overeating and obesity. PMID:25459293

Zhang, Bin; Tian, Derun; Yu, Chunshui; Zhang, Jing; Tian, Xiao; von Deneen, Karen M; Zang, Yufeng; Walter, Martin; Liu, Yijun

2015-01-01

378

Adaptive filtering for global interference cancellation and real-time recovery of evoked brain activity: a Monte Carlo simulation study  

E-print Network

The sensitivity of near-infrared spectroscopy (NIRS) to evoked brain activity is reduced by physiological interference in at least two locations: 1. the superficial scalp and skull layers, and 2. in brain tissue itself. ...

Zhang, Quan

379

Understanding brain dysfunction in sepsis  

PubMed Central

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

2013-01-01

380

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

PubMed

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

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

2014-11-01

381

A single PHN subject brain activityA single PHN subject brain activity for tactile stimulation in thefor tactile stimulation in the  

E-print Network

as in back pain, and different from arthritis pain. · LidoDerm treatment seems to decrease brain activity and chronic back pain. METHODS RESULTS PainIntensity 0 2 4 6 8 1 0 Before Treatment 6 h post Treatment 2 weeks back pain (average of 13 patients for spontaneous back pain). ·PHN patients were scanned prior, 6 hours

Apkarian, A. Vania

382

ADHD- and Medication-Related Brain Activation Effects in Concordantly Affected Parent-Child Dyads with ADHD  

ERIC Educational Resources Information Center

Background: Several studies have documented fronto-striatal dysfunction in children and adolescents with attention deficit/hyperactivity disorder (ADHD) using response inhibition tasks. Our objective was to examine functional brain abnormalities among youths and adults with ADHD and to examine the relations between these neurobiological…

Epstein, Jeffery N.; Casey, B. J.; Tonev, Simon T.; Davidson, Matthew C.; Reiss, Allan L.; Garrett, Amy; Hinshaw, Stephen P.; Greenhill, Laurence L.; Glover, Gary; Shafritz, Keith M.; Vitolo, Alan; Kotler, Lisa A.; Jarrett, Matthew A.; Spicer, Julie

2007-01-01

383

Nitric oxide spin-trapping and NADPH-diaphorase activity in mature rat brain after injury.  

PubMed

Traumatic brain injury (TBI) induces inflammatory reactions, and one of the essential mediators of this reaction is nitric oxide (NO). The action of this compound is still under study because no clear consensus has been reached about its exact action in the central nervous system. Further, it is unknown if, in the damaged brain, its neuroprotective activity outweighs its putative neurodegenerative properties. Using ferrous-diethyldithiocarbamate chelate, a lipophilic spin trap for NO detection by electron paramagnetic resonance (EPR) spectroscopy, we followed NO production in injured brain of mature Wistar rats. To relate changes in the amount of NO in the lesioned brain to the activity of NO synthase (NOS), this study also used NADPH-diaphorase staining. Our data show a rapid drop of NO concentration in the damaged brain below control values. This phenomenon persisted over several hours postinjury and varied with brain region. This decrease in NO concentration was accompanied by a simultaneous increase in the number of NADPH-diaphorase-positive cells, perhaps indicative of increased NOS activity. It is therefore assumed that, in the lesioned brain, a very rapid removal of NO occurs via its transformation to other reactive species such as peroxynitrite, which further adversely influence the damaged tissue. PMID:18159996

Ziaja, Marek; Pyka, Janusz; Machowska, Anna; Maslanka, Anna; Plonka, Przemyslaw M

2007-12-01

384

Breastfeeding, Brain Activation to Own Infant Cry, and Maternal Sensitivity  

ERIC Educational Resources Information Center

Background: Research points to the importance of breastfeeding for promoting close mother-infant contact and social-emotional development. Recent functional magnetic resonance imaging (fMRI) studies have identified brain regions related to maternal behaviors. However, little research has addressed the neurobiological mechanisms underlying the…

Kim, Pilyoung; Feldman, Ruth; Mayes, Linda C.; Eicher, Virginia; Thompson, Nancy; Leckman, James F.; Swain, James E.

2011-01-01

385

Inhibition in Verbal Working Memory Revealed by Brain Activation  

Microsoft Academic Search

There are many occasions in which humans and other animals must inhibit the production of some behavior or inhibit the processing of some internal representation. Success in inhibitory processing under normal circumstances can be revealed by the fact that certain brain pathologies render inhibitory processing ineffective. These pathologies often have been associated with damage to frontal cortex, including lateral and

John Jonides; Edward E. Smith; Christy Marshuetz; Robert A. Koeppe; Patricia A. Reuter-Lorenz

1998-01-01

386

Effects of Traumatic Brain Injury on Working Memory-Related Brain Activation in Adolescents  

Microsoft Academic Search

Eight adolescents (ages 13–18 years) who sustained traumatic brain injury (TBI) and eight gender- and age-matched typically developing (TD) adolescents underwent event-related functional MRI (fMRI) while performing a Sternberg letter recognition task. Encoding, maintenance, and retrieval were examined with memory loads of one or four items during imaging. Both groups performed above a 70% accuracy criterion and did not differ

Mary R. Newsome; Joel L. Steinberg; Randall S. Scheibel; Maya Troyanskaya; Z. Chu; Gerri Hanten; Hanzhang Lu; Xiaodi Lin; Jill V. Hunter; Carmen Vasquez; Jennifer Zientz; Xiaoqi Li; Elisabeth A. Wilde; Harvey S. Levin

2008-01-01

387

Multi-scale integration and predictability in resting state brain activity  

PubMed Central

The human brain displays heterogeneous organization in both structure and function. Here we develop a method to characterize brain regions and networks in terms of information-theoretic measures. We look at how these measures scale when larger spatial regions as well as larger connectome sub-networks are considered. This framework is applied to human brain fMRI recordings of resting-state activity and DSI-inferred structural connectivity. We find that strong functional coupling across large spatial distances distinguishes functional hubs from unimodal low-level areas, and that this long-range functional coupling correlates with structural long-range efficiency on the connectome. We also find a set of connectome regions that are both internally integrated and coupled to the rest of the brain, and which resemble previously reported resting-state networks. Finally, we argue that information-theoretic measures are useful for characterizing the functional organization of the brain at multiple scales. PMID:25104933

Kolchinsky, Artemy; van den Heuvel, Martijn P.; Griffa, Alessandra; Hag