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1

Abnormal Brain Activity Changes in Patients with Migraine: A Short-Term Longitudinal Study  

PubMed Central

Background and Purpose Whether or not migraine can cause cumulative brain alterations due to frequent migraine-related nociceptive input in patients is largely unclear. The aim of this study was to characterize longitudinal changes in brain activity between repeated observations within a short time interval in a group of female migraine patients, using resting-state functional magnetic resonance imaging. Methods Nineteen patients and 20 healthy controls (HC) participated in the study. Regional homogeneity (ReHo) and functional interregional connectivity were assessed to determine the focal and global features of brain dysfunction in migraine. The relationship between changes in headache parameters and longitudinal brain alterations were also investigated. Results All patients reported that their headache activity increased over time. Abnormal ReHo changes in the patient group relative to the HC were found in the putamen, orbitofrontal cortex, secondary somatosensory cortex, brainstem, and thalamus. Moreover, these brain regions exhibited longitudinal ReHo changes at the 6-week follow-up examination. These headache activity changes were accompanied by disproportionately dysfunctional connectivity in the putamen in the migraine patients, as revealed by functional connectivity analysis, suggesting that the putamen plays an important role in integrating diverse information among other migraine-related brain regions. Conclusions The results obtained in this study suggest that progressive brain aberrations in migraine progress as a result of increased headache attacks.

Zhao, Ling; Yan, Xuemei; Dun, Wanghuan; Yang, Jing; Huang, Liyu; Kai, Yuan; Yu, Dahua; Qin, Wei; Jie, Tian

2014-01-01

2

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.

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

2013-01-01

3

Abnormal amplitude of low-frequency fluctuations of intrinsic brain activity in Alzheimer's disease.  

PubMed

We used resting-state functional magnetic resonance imaging to measure the amplitude of low-frequency fluctuations (ALFF) of intrinsic brain activity in 23 patients with moderate Alzheimer's disease (AD) and 27 age- and gender-matched healthy controls. Two different frequency bands were analyzed (slow-5:0.01-0.027 Hz; slow-4:0.027-0.073 Hz). In many brain regions, widespread ALFF differences between the two frequency bands were observed, including predominantly the posterior cingulate cortex/precuneus (PCC/PCu), hippocampus/parahippocampal gyrus (Hip/PHG), insula, thalamus, and basal ganglia. Compared to controls, AD patients showed decreased ALFF values in the bilateral PCC/PCu, inferior parietal lobe, and several temporal regions, and increased ALFF values mainly in the bilateral Hip/PHG, and middle and inferior temporal gyri. Intriguingly, the ALFF abnormalities in the left PCu, left supramarginal gyrus, and several temporal regions were greater in the slow-5 band compared to the slow-4 band. Moreover, correcting for gray matter volume loss significantly affected the functional analytical results, suggesting that gray matter loss can partially account for the functional imaging analytical results obtained in AD. Finally, we showed that regions with changes in ALFF demonstrated a significant correlation with patient cognitive performance as measured using Mini-Mental State Examination scores. The results also demonstrated a significant correlation between hippocampal volume and the ALFF in slow-5 band in the AD group. This study demonstrated widespread ALFF abnormalities of intrinsic brain activity in AD and revealed that the ALFF abnormalities in severe specific regions were frequency-dependent. Taken together, our findings provided novel insights into the pathophysiological mechanism of AD and may be helpful in the development of imaging biomarkers for disease diagnosis. PMID:24473186

Liu, Xuena; Wang, Siqi; Zhang, Xinqing; Wang, Zhiqun; Tian, Xiaojie; He, Yong

2014-01-01

4

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

PubMed

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; Fan, Jin

2014-01-01

5

Brain state-dependent abnormal LFP activity in the auditory cortex of a schizophrenia mouse model  

PubMed Central

In schizophrenia, evoked 40-Hz auditory steady-state responses (ASSRs) are impaired, which reflects the sensory deficits in this disorder, and baseline spontaneous oscillatory activity also appears to be abnormal. It has been debated whether the evoked ASSR impairments are due to the possible increase in baseline power. GABAergic interneuron-specific NMDA receptor (NMDAR) hypofunction mutant mice mimic some behavioral and pathophysiological aspects of schizophrenia. To determine the presence and extent of sensory deficits in these mutant mice, we recorded spontaneous local field potential (LFP) activity and its click-train evoked ASSRs from primary auditory cortex of awake, head-restrained mice. Baseline spontaneous LFP power in the pre-stimulus period before application of the first click trains was augmented at a wide range of frequencies. However, when repetitive ASSR stimuli were presented every 20 s, averaged spontaneous LFP power amplitudes during the inter-ASSR stimulus intervals in the mutant mice became indistinguishable from the levels of control mice. Nonetheless, the evoked 40-Hz ASSR power and their phase locking to click trains were robustly impaired in the mutants, although the evoked 20-Hz ASSRs were also somewhat diminished. These results suggested that NMDAR hypofunction in cortical GABAergic neurons confers two brain state-dependent LFP abnormalities in the auditory cortex; (1) a broadband increase in spontaneous LFP power in the absence of external inputs, and (2) a robust deficit in the evoked ASSR power and its phase-locking despite of normal baseline LFP power magnitude during the repetitive auditory stimuli. The “paradoxically” high spontaneous LFP activity of the primary auditory cortex in the absence of external stimuli may possibly contribute to the emergence of schizophrenia-related aberrant auditory perception.

Nakao, Kazuhito; Nakazawa, Kazu

2014-01-01

6

Abnormal spontaneous brain activity in medication-naïve ADHD children: A resting state fMRI study  

Microsoft Academic Search

Abnormal baseline brain functional connectivity in attention-deficit\\/hyperactivity disorder (ADHD) has been revealed in a number of studies by using resting-state functional MRI (rfMRI). The aim of this study was to investigate the spontaneous frontal activities in medication-naïve ADHD boys using the rfMRI derived index, amplitude of low-frequency fluctuation (ALFF). In total 17 ADHD boys and 17 matched controls were recruited

Hong Yang; Qi-Zhu Wu; Lan-Ting Guo; Qian-Qian Li; Xiang-Yu Long; Xiao-Qi Huang; Raymond C. K. Chan; Qi-Yong Gong

2011-01-01

7

Tinnitus Perception and Distress Is Related to Abnormal Spontaneous Brain Activity as Measured by Magnetoencephalography  

Microsoft Academic Search

BackgroundThe neurophysiological mechanisms underlying tinnitus perception are not well understood. Surprisingly, there have been no group studies comparing abnormalities in ongoing, spontaneous neuronal activity in individuals with and without tinnitus perception.Methods and FindingsHere, we show that the spontaneous neuronal activity of a group of individuals with tinnitus (n = 17) is characterised by a marked reduction in alpha (8–12 Hz)

Nathan Weisz; Stephan Moratti; Marcus Meinzer; Katalin Dohrmann; Thomas Elbert

2005-01-01

8

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.

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

9

Brain Stem MRI Signal Abnormalities in CADASIL  

Microsoft Academic Search

Background—We recently showed that the severity of MRI signal abnormalities increases with age in CADASIL, an arteriopathy due to mutations of notch 3 gene on chromosome 19. Previous results also suggest that the various hemispheric subcortical areas have a different vulnerability to ischemia in this disease. The distribution of the lesions at the brain stem level has not yet been

H. Chabriat; R. Mrissa; C. Levy; K. Vahedi; H. Taillia; M. T. Iba-Zizen; A. Joutel; E. Tournier-Lasserve; M.-G. Bousser

10

Anatomical brain networks on the prediction of abnormal brain states.  

PubMed

Graph-based brain anatomical network analysis models the brain as a graph whose nodes represent structural/functional regions, whereas the links between them represent nervous fiber connections. Initial studies of brain anatomical networks using this approach were devoted to describe the key organizational principles of the normal brain, while current trends seem to be more focused on detecting network alterations associated to specific brain disorders. Anatomical networks reconstructed using diffusion-weighed magnetic resonance-imaging techniques can be particularly useful in predicting abnormal brain states in which the white matter structure and, subsequently, the interconnections between gray matter regions are altered (e.g., due to the presence of diseases such as schizophrenia, stroke, multiple sclerosis, and dementia). This article offers an overview from early gross connectional anatomy explorations until more recent advances on anatomical brain network reconstruction approaches, with a specific focus on how the latter move toward the prediction of abnormal brain states. While anatomical graph-based predictor approaches are still at an early stage, they bear promising implications for individualized clinical diagnosis of neurological and psychiatric disorders, as well as for neurodevelopmental evaluations and subsequent assisted creation of educational strategies related to specific cognitive disorders. PMID:23249224

Iturria-Medina, Yasser

2013-01-01

11

Abnormal Baseline Brain Activity in Non-Depressed Parkinson's Disease and Depressed Parkinson's Disease: A Resting-State Functional Magnetic Resonance Imaging Study  

PubMed Central

Depression is the most common psychiatric disorder observed in Parkinson’s disease (PD) patients, however the neural contribution to the high rate of depression in the PD group is still unclear. In this study, we used resting-state functional magnetic resonance imaging (fMRI) to investigate the underlying neural mechanisms of depression in PD patients. Twenty-one healthy individuals and thirty-three patients with idiopathic PD, seventeen of whom were diagnosed with major depressive disorder, were recruited. An analysis of amplitude of low-frequency fluctuations (ALFF) was performed on the whole brain of all subjects. Our results showed that depressed PD patients had significantly decreased ALFF in the dorsolateral prefrontal cortex (DLPFC), the ventromedial prefrontal cortex (vMPFC) and the rostral anterior cingulated cortex (rACC) compared with non-depressed PD patients. A significant positive correlation was found between Hamilton Depression Rating Scale (HDRS) and ALFF in the DLPFC. The findings of changed ALFF in these brain regions implied depression in PD patients may be associated with abnormal activities of prefrontal-limbic network.

Wen, Xuyun; Wu, Xia; Liu, Jiangtao; Li, Ke; Yao, Li

2013-01-01

12

Calcium transport abnormality in uremic rat brain synaptosomes.  

PubMed

Brain calcium is elevated in patients and laboratory animals with uremia. The significance of this finding is unclear. We evaluated calcium transport in brain of both normal and acutely uremic rats (blood urea nitrogen = 250 mg/dl) by performing studies in synaptosomes from rat brain cerebral cortex. Synaptosomes are vesicular presynaptic nerve endings from brain that contain mitochondria and are metabolically active. Two mechanisms of calcium transport were evaluated using radioactive 45Ca++ as a tracer. Both mechanisms were evaluated in the absence of exogenously administered parathyroid hormone (PTH). We first evaluated Na+-Ca++ exchange in vesicles that were loaded with NaCl in an external media containing 10 microM CaCl2. Both initial rates of calcium transport and equilibrium levels of calcium accumulation in synaptosomes prepared from uremic rats were significantly greater (P less than 0.005) than in normal. To assess calcium efflux, ATP-dependent calcium uptake (1 mM ATP) was studied in inverted plasma membrane vesicles loaded with KCl. In the uremic synaptosomes, a significant increase (P less than 0.005) in ATP-dependent calcium uptake was observed as compared with the normal. These studies show that (a) Calcium accumulation via the Na+-Ca++ exchanger is increased in synaptosomes prepared from uremic rat brain. (b) Calcium influx into inverted plasma membrane vesicles from uremic rats via the ATP-dependent calcium transport mechanism is increased when compared with normal. (c) The increased calcium accumulation in uremia by both Na+-Ca++ exchange and ATP-dependent calcium transport mechanism appears to be a result of increased synaptosomal membrane permeability to calcium. Both these abnormalities of calcium transport in uremia would tend to increase brain extracellular calcium in vivo. The defects observed in uremia do not appear to be readily reversible, and the relationship to PTH is presently unclear. These abnormalities may affect neurotransmission in the uremic state. PMID:4056053

Fraser, C L; Sarnacki, P; Arieff, A I

1985-11-01

13

Abnormal brain synchrony in Down Syndrome.  

PubMed

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

14

Brain Anatomical Abnormalities in High-Risk Individuals, First-Episode, and Chronic Schizophrenia: An Activation Likelihood Estimation Meta-analysis of Illness Progression  

PubMed Central

Objective: The present study reviewed voxel-based morphometry (VBM) studies on high-risk individuals with schizophrenia, patients experiencing their first-episode schizophrenia (FES), and those with chronic schizophrenia. We predicted that gray matter abnormalities would show progressive changes, with most extensive abnormalities in the chronic group relative to FES and least in the high-risk group. Method: Forty-one VBM studies were reviewed. Eight high-risk studies, 14 FES studies, and 19 chronic studies were analyzed using anatomical likelihood estimation meta-analysis. Results: Less gray matter in the high-risk group relative to controls was observed in anterior cingulate regions, left amygdala, and right insula. Lower gray matter volumes in FES compared with controls were also found in the anterior cingulate and right insula but not the amygdala. Lower gray matter volumes in the chronic group were most extensive, incorporating similar regions to those found in FES and high-risk groups but extending to superior temporal gyri, thalamus, posterior cingulate, and parahippocampal gryus. Subtraction analysis revealed less frontotemporal, striatal, and cerebellar gray matter in FES than the high-risk group; the high-risk group had less gray matter in left subcallosal gyrus, left amygdala, and left inferior frontal gyrus compared with FES. Subtraction analysis confirmed lower gray matter volumes through ventral-dorsal anterior cingulate, right insula, left amygdala and thalamus in chronic schizophrenia relative to FES. Conclusions: Frontotemporal brain structural abnormalities are evident in nonpsychotic individuals at high risk of developing schizophrenia. The present meta-analysis indicates that these gray matter abnormalities become more extensive through first-episode and chronic illness. Thus, schizophrenia appears to be a progressive cortico-striato-thalamic loop disorder.

Chan, Raymond C. K.; Di, Xin; McAlonan, Grainne M.; Gong, Qi-yong

2011-01-01

15

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.

2013-01-01

16

Molecular Abnormalities in Postmortem Brains of Subjects with Mood Disorders  

Microsoft Academic Search

Biochemical and structural abnormalities have been reported in postmortem brain tissue from patients with mood disorders. Studies of the molecular pharmacology of drugs used in the treatment of mood disorders have led to a reinterpretation of earlier models of neuropathology in these diseases. Noradrenergic and serotonergic hypotheses have been expanded to include postsynaptic intracellular signal transduction pathways, regulation of gene

Dariush Dowlatshahi

2003-01-01

17

Molecular abnormalities in postmortem brains of subjects with mood disorders  

Microsoft Academic Search

Biochemical and structural abnormalities have been reported in postmortem brain tissue from patients with mood disorders. Studies of the molecular pharmacology of drugs used in the treatment of mood disorders have led to a reinterpretation of earlier models of neuropathology in these diseases. Noradrenergic and serotonergic hypotheses have been expanded to include postsynaptic intracellular signal transduction pathways, regulation of gene

Dariush Dowlatshahi

2003-01-01

18

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

19

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

20

Abnormal Brain Functional Connectivity of the Hypothalamus in Cluster Headaches  

PubMed Central

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

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

2013-01-01

21

Abnormal brain structure implicated in stimulant drug addiction.  

PubMed

Addiction to drugs is a major contemporary public health issue, characterized by maladaptive behavior to obtain and consume an increasing amount of drugs at the expense of the individual's health and social and personal life. We discovered abnormalities in fronto-striatal brain systems implicated in self-control in both stimulant-dependent individuals and their biological siblings who have no history of chronic drug abuse; these findings support the idea of an underlying neurocognitive endophenotype for stimulant drug addiction. PMID:22301321

Ersche, Karen D; Jones, P Simon; Williams, Guy B; Turton, Abigail J; Robbins, Trevor W; Bullmore, Edward T

2012-02-01

22

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.

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

2010-01-01

23

Abnormal Brain Network Organization in Body Dysmorphic Disorder  

PubMed Central

Body dysmorphic disorder (BDD) is characterized by preoccupation with misperceived defects of appearance, causing significant distress and disability. Previous studies suggest abnormalities in information processing characterized by greater local relative to global processing. The purpose of this study was to probe whole-brain and regional white matter network organization in BDD, and to relate this to specific metrics of symptomatology. We acquired diffusion-weighted 34-direction MR images from 14 unmedicated participants with DSM-IV BDD and 16 healthy controls, from which we conducted whole-brain deterministic diffusion tensor imaging tractography. We then constructed white matter structural connectivity matrices to derive whole-brain and regional graph theory metrics, which we compared between groups. Within the BDD group, we additionally correlated these metrics with scores on psychometric measures of BDD symptom severity as well as poor insight/delusionality. The BDD group showed higher whole-brain mean clustering coefficient than controls. Global efficiency negatively correlated with BDD symptom severity. The BDD group demonstrated greater edge betweenness centrality for connections between the anterior temporal lobe and the occipital cortex, and between bilateral occipital poles. This represents the first brain network analysis in BDD. Results suggest disturbances in whole brain structural topological organization in BDD, in addition to correlations between clinical symptoms and network organization. There is also evidence of abnormal connectivity between regions involved in lower-order visual processing and higher-order visual and emotional processing, as well as interhemispheric visual information transfer. These findings may relate to disturbances in information processing found in previous studies.

Arienzo, Donatello; Leow, Alex; Brown, Jesse A; Zhan, Liang; GadElkarim, Johnson; Hovav, Sarit; Feusner, Jamie D

2013-01-01

24

Abuse of amphetamines and structural abnormalities in the brain.  

PubMed

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 including 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

2008-10-01

25

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.

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

26

Neurobehavioral abnormalities in a brain-specific NADPH-cytochrome P450 reductase knockout mouse model  

PubMed Central

The aim of the present study was to test a new hypothesis that brain cytochrome P450 reductase (CPR) and CPR-dependent enzymes play important roles in behavioral performance. A mouse model with brain neuron-specific deletion of the Cpr gene (brain-Cpr-null) was recently generated. Brain-Cpr-null mice and wild-type (WT) littermates were compared in a variety of behavioral assays. Notable differences were found in the exploratory behavior assay: for both males and females, activity in the center of the chamber was significantly higher for brain-Cpr-null than for WT mice on days 2 and 3 of the assay, although no significant difference was found between the two groups in anxiety-like behavior in the elevated zero maze. Furthermore, in the fear-conditioning assay, brain-Cpr-null mice exhibited significantly less activity suppression than did WT controls. This deficit in activity suppression was not accompanied by any difference between WT and brain-Cpr-null mice in nociceptive responses to foot shocks. Abnormal activity suppression was also observed in both male and female brain-Cpr-null mice during the contextual memory test. However, in the Morris water maze assay, the brain-Cpr-null and WT mice were indistinguishable, indicating normal spatial memory in the mutant mice. These data collectively indicate a novel role of the Cpr gene in fear conditioning and memory.

Fang, Cheng; Bolivar, Valerie J.; Gu, Jun; Yang, Weizhu; Zeitlin, Scott O.; Ding, Xinxin

2012-01-01

27

Relationship between brain abnormalities and cognitive profile in Williams syndrome.  

PubMed

Previous studies have shown inconsistent results when reporting brain abnormalities in Williams syndrome (WS). This makes an interpretation of clinical and behavioural data uncertain in terms of anatomical localization of brain tissue changes. In this study we employed voxel based morphometry to directly investigate the regional distribution of grey matter (GM) density as a function of individual neuropsychological profiles in individuals with WS. GM maps were regressed against the neuropsychological measures on which WS individuals performed worse than controls. Results showed an association between the regional GM density in the cerebellum, bilaterally, the right Supplementary Motor Area, the right fusiform gyrus, and measures of morpho-syntactic ability. An association was also found between measures of visuo-spatial and visuo-motor abilities and regional GM density in the left cerebellum, left parietal lobule, right superior and left orbital frontal gyri. The study shows the potential to clarify the anatomical substrate underlying specific cognitive deficits in WS. PMID:21153484

Menghini, Deny; Di Paola, Margherita; Federico, Francesca; Vicari, Stefano; Petrosini, Laura; Caltagirone, Carlo; Bozzali, Marco

2011-05-01

28

Abnormal topological organization of structural brain networks in schizophrenia.  

PubMed

Schizophrenia is a debilitating mental disorder characterized by disturbances of thought and emotion as well as neurocognitive deficits. It is hypothesized that the core symptoms of schizophrenia arise from the inability to integrate neural processes segregated across distributed brain regions. Graph theory allows us to verify this hypothesis at large-scale structural network level. In this study, a sample of 101 schizophrenic patients and 101 healthy controls was included. We sought to investigate the abnormality of network topological organization in patients with schizophrenia by using the cortical thickness measurement from magnetic resonance imaging. Brain networks were constructed by thresholding cortical thickness correlation matrices of 78 regions and analyzed using graph theoretical approaches. Compared to healthy controls, patients showed increased characteristic path length and clustering coefficient in the structural cortical networks. Moreover, schizophrenia patients were associated with reduced nodal centrality in several regions of the default network and increased nodal centrality mainly in primary cortex and paralimbic cortex regions. These findings suggest that the structural networks of schizophrenic patients have a less optimal topological organization, resulting in reduced capacity to integrate information across brain regions. PMID:22981811

Zhang, Yuanchao; Lin, Lei; Lin, Ching-Po; Zhou, Yuan; Chou, Kun-Hsien; Lo, Chun-Yi; Su, Tung-Ping; Jiang, Tianzi

2012-11-01

29

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.

2013-01-01

30

Neuroendocrine abnormalities in patients with traumatic brain injury  

NASA Technical Reports Server (NTRS)

This article provides an overview of hypothalamic and pituitary alterations in brain trauma, including the incidence of hypothalamic-pituitary damage, injury mechanisms, features of the hypothalamic-pituitary defects, and major hypothalamic-pituitary disturbances in brain trauma. While hypothalamic-pituitary lesions have been commonly described at postmortem examination, only a limited number of clinical cases of traumatic hypothalamic-pituitary dysfunction have been reported, probably because head injury of sufficient severity to cause hypothalamic and pituitary damage usually leads to early death. With the improvement in rescue measures, an increasing number of severely head-injured patients with hypothalamic-pituitary dysfunction will survive to be seen by clinicians. Patterns of endocrine abnormalities following brain trauma vary depending on whether the injury site is in the hypothalamus, the anterior or posterior pituitary, or the upper or lower portion of the pituitary stalk. Injury predominantly to the hypothalamus can produce dissociated ACTH-cortisol levels with no response to insulin-induced hypoglycemia and a limited or failed metopirone test, hypothyroxinemia with a preserved thyroid-stimulating hormone response to thyrotropin-releasing hormone, low gonadotropin levels with a normal response to gonadotropin-releasing hormone, a variable growth hormone (GH) level with a paradoxical rise in GH after glucose loading, hyperprolactinemia, the syndrome of inappropriate ADH secretion (SIADH), temporary or permanent diabetes insipidus (DI), disturbed glucose metabolism, and loss of body temperature control. Severe damage to the lower pituitary stalk or anterior lobe can cause low basal levels of all anterior pituitary hormones and eliminate responses to their releasing factors. Only a few cases showed typical features of hypothalamic or pituitary dysfunction. Most severe injuries are sufficient to damage both structures and produce a mixed endocrine picture. Increased intracranial pressure, which releases vasopressin by altering normal hypothalamic anatomy, may represent a unique type of stress to neuroendocrine systems and may contribute to adrenal secretion by a mechanism that requires intact brainstem function. Endocrine function should be monitored in brain-injured patients with basilar skull fractures and protracted posttraumatic amnesia, and patients with SIADH or DI should be closely monitored for other endocrine abnormalities.

Yuan, X. Q.; Wade, C. E.

1991-01-01

31

Structural Brain Abnormalities and Suicidal Behavior in Borderline Personality Disorder  

PubMed Central

Background Structural brain abnormalities have been demonstrated in subjects with BPD in prefrontal and fronto-limbic regions involved in the regulation of emotion and impulsive behavior, executive cognitive function and episodic memory. Impairment in these cognitive functions is associated with increased vulnerability to suicidal behavior. We compared BPD suicide attempters and non-attempters, high and low lethality attempters to healthy controls to identify neural circuits associated with suicidal behavior in BPD. Methods Structural MRI scans were obtained on 68 BPD subjects (16 male, 52 female), defined by IPDE and DIB/R criteria, and 52 healthy controls (HC: 28 male, 24 female). Groups were compared by diagnosis, attempt status, and attempt lethality. ROIs were defined for areas reported to have structural or metabolic abnormalities in BPD, and included: mid-inf. orbitofrontal cortex, mid-sup temporal cortex, anterior cingulate, insula, hippocampus, amygdala, fusiform, lingual and parahippocampal gyri. Data were analyzed using optimized voxel-based morphometry implemented with DARTEL in SPM5, co-varied for age and gender, corrected for cluster extent (p<.001). Results Compared to HC, BPD attempters had significantly diminished gray matter concentrations in 8 of 9 ROIs, non-attempters in 5 of 9 ROIs. Within the BPD sample, attempters had diminished gray matter in Lt. insula compared to non-attempters. High lethality attempters had significant decreases in Rt. mid-sup. temporal gyrus, Rt. mid-inf. orbitofrontal gyrus, Rt. insular cortex, Lt. fusiform gyrus, Lt. lingual gyrus and Rt. parahippocampal gyrus compared to low lethality attempters. Conclusions Specific structural abnormalities discriminate BPD attempters from non-attempters and high from low lethality attempters.

Soloff, Paul H.; Pruitt, Patrick; Sharma, Mohit; Radwan, Jacqueline; White, Richard; Diwadkar, Vaibhav A.

2012-01-01

32

Chromosome abnormalities in chronic active hepatitis  

PubMed Central

An investigation on human peripheral blood lymphocyte chromosomes in chronic active hepatitis was carried out. A higher percentage of chromatid and chromosome lesions was recorded in all patients studied as compared with control groups—normal individuals, healthy subjects who had suffered from acute viral hepatitis, patients with alcoholic liver disease, and patients with mechanical jaundice due to cancer. The possible origin of these abnormalities is discussed.

Stefanescu, D. T.; Moanga, M.; Teodorescu, M.; Brucher, J.

1972-01-01

33

Diffusion 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 neurobehavioral sequelae. However, little is known about underlying pathophysiology and how injuries change as a function of recovery. Fractional anisotropy, axial diffusivity, and radial diffusivity were examined in 15 semi-acute pmTBI patients and 15 well-matched controls, with a subset of participants returning for a second visit. A novel analytic strategy was applied to capture spatially heterogeneous white matter injuries (lesions) in addition to standard analyses. Evidence of cognitive dysfunction after pmTBI was observed in the domains of attention (p = 0.02, d = -0.92) and processing speed (p = 0.05, d = -0.73) semi-acutely. Region of interest (ROI) and voxelwise analyses indicated increased anisotropic diffusion for pmTBI patients, with an elevated number of clusters with high anisotropy. Metrics of increased anisotropy were able to objectively classify pmTBI from healthy controls at 90% accuracy but were not associated with neuropsychological deficits. Little evidence of recovery in white matter abnormalities was observed over a 4-month interval in returning patients, indicating that physiological recovery may lag behind subjective reports of normality. Increased anisotropic diffusion has been previously linked with cytotoxic edema after TBI, and the magnitude and duration of these abnormalities appear to be greater in pediatric patients. Current findings suggest that developing white matter may be more susceptible to initial mechanical injury forces and that anisotropic diffusion provides an objective biomarker of pmTBI. PMID:23238712

Mayer, Andrew R; Ling, Josef M; Yang, Zhen; Pena, Amanda; Yeo, Ronald A; Klimaj, Stefan

2012-12-12

34

The Brain Activity Map  

PubMed Central

Neuroscientists have made impressive advances in understanding the microscale function of single neurons and the macroscale activity of the human brain. One can probe molecular and biophysical aspects of individual neurons and also view the human brain in action with magnetic resonance imaging (MRI) or magnetoencephalography (MEG). However, the mechanisms of perception, cognition, and action remain mysterious because they emerge from the real-time interactions of large sets of neurons in densely interconnected, widespread neural circuits.

Alivisatos, A. Paul; Chun, Miyoung; Church, George M.; Deisseroth, Karl; Donoghue, John P.; Greenspan, Ralph J.; McEuen, Paul L.; Roukes, Michael L.; Sejnowski, Terrence J.; Weiss, Paul S.; Yuste, Rafael

2013-01-01

35

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

36

The influence of brain abnormalities on psychosocial development, criminal history and paraphilias in sexual murderers.  

PubMed

The aim of this study was to investigate the number and type of brain abnormalities and their influence on psychosocial development, criminal history and paraphilias in sexual murderers. We analyzed psychiatric court reports of 166 sexual murderers and compared a group with notable signs of brain abnormalities (N = 50) with those without any signs (N = 116). Sexual murderers with brain abnormalities suffered more from early behavior problems. They were less likely to cohabitate with the victim at the time of the homicide and had more victims at the age of six years or younger. Psychiatric diagnoses revealed a higher total number of paraphilias: Transvestic fetishism and paraphilias not otherwise specified were more frequent in offenders with brain abnormalities. A binary logistic regression identified five predictors that accounted for 46.8% of the variance explaining the presence of brain abnormalities. Our results suggest the importance of a comprehensive neurological and psychological examination of this special offender group. PMID:16225232

Briken, Peer; Habermann, Niels; Berner, Wolfgang; Hill, Andreas

2005-09-01

37

Structural Abnormalities in the Brains of Human Subjects Who Use Methamphetamine  

Microsoft Academic Search

We visualize, for the first time, the profile of structural deficits in the human brain associated with chronic methamphetamine (MA) abuse. Studies of human subjects who have used MA chronically have revealed deficits in dopaminergic and serotonergic systems and cerebral metabolic abnormalities. Using magnetic resonance imaging (MRI) and new computational brain-mapping techniques, we determined the pattern of structural brain alterations

Paul M. Thompson; Kiralee M. Hayashi; Sara L. Simon; Jennifer A. Geaga; Michael S. Hong; Yihong Sui; Jessica Y. Lee; Arthur W. Toga; Walter Ling; Edythe D. London

2004-01-01

38

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

39

White Matter Abnormalities in Veterans With Mild Traumatic Brain Injury  

PubMed Central

Objective It has been estimated that 10%–20% of U.S. veterans of the wars in Iraq and Afghanistan experienced mild traumatic brain injury (TBI), mostly secondary to blast exposure. Diffusion tensor imaging (DTI) may detect subtle white matter changes in both the acute and chronic stages of mild TBI and thus has the potential to detect white matter damage in patients with TBI. The authors used DTI to examine white matter integrity in a relatively large group of veterans with a history of mild TBI. Method DTI images from 72 veterans of the wars in Iraq and Afghanistan who had mild TBI were compared with DTI images from 21 veterans with no exposure to TBI during deployment. Conventional voxel-based analysis as well as a method of identifying spatially heterogeneous areas of decreased fractional anisotropy (“potholes”) were used. Veterans also underwent psychiatric and neuropsychological assessments. Results Voxel-based analysis did not reveal differences in DTI parameters between the veterans with mild TBI and those with no TBI. However, the veterans with mild TBI had a significantly higher number of potholes than those without TBI. The difference in the number of potholes was not influenced by age, time since trauma, a history of mild TBI unrelated to deployment, or coexisting psychopathology. The number of potholes was correlated with the severity of TBI and with performance in executive functioning tasks. Conclusions Veterans who had blast-related mild TBI showed evidence of multifocal white matter abnormalities that were associated with severity of the injury and with relevant functional measures. Overall, white matter potholes may constitute a sensitive biomarker of axonal injury that can be identified in mild TBI at acute and chronic stages of its clinical course.

Jorge, Ricardo E.; Acion, Laura; White, Tonya; Tordesillas-Gutierrez, Diana; Pierson, Ronald; Crespo-Facorro, Benedicto; Magnotta, Vincent A.

2014-01-01

40

Co-localisation of abnormal brain structure and function in specific language impairment.  

PubMed

We assessed the relationship between brain structure and function in 10 individuals with specific language impairment (SLI), compared to six unaffected siblings, and 16 unrelated control participants with typical language. Voxel-based morphometry indicated that grey matter in the SLI group, relative to controls, was increased in the left inferior frontal cortex and decreased in the right caudate nucleus and superior temporal cortex bilaterally. The unaffected siblings also showed reduced grey matter in the caudate nucleus relative to controls. In an auditory covert naming task, the SLI group showed reduced activation in the left inferior frontal cortex, right putamen, and in the superior temporal cortex bilaterally. Despite spatially coincident structural and functional abnormalities in frontal and temporal areas, the relationships between structure and function in these regions were different. These findings suggest multiple structural and functional abnormalities in SLI that are differently associated with receptive and expressive language processing. PMID:22137677

Badcock, Nicholas A; Bishop, Dorothy V M; Hardiman, Mervyn J; Barry, Johanna G; Watkins, Kate E

2012-03-01

41

Co-localisation of abnormal brain structure and function in specific language impairment  

PubMed Central

We assessed the relationship between brain structure and function in 10 individuals with specific language impairment (SLI), compared to six unaffected siblings, and 16 unrelated control participants with typical language. Voxel-based morphometry indicated that grey matter in the SLI group, relative to controls, was increased in the left inferior frontal cortex and decreased in the right caudate nucleus and superior temporal cortex bilaterally. The unaffected siblings also showed reduced grey matter in the caudate nucleus relative to controls. In an auditory covert naming task, the SLI group showed reduced activation in the left inferior frontal cortex, right putamen, and in the superior temporal cortex bilaterally. Despite spatially coincident structural and functional abnormalities in frontal and temporal areas, the relationships between structure and function in these regions were different. These findings suggest multiple structural and functional abnormalities in SLI that are differently associated with receptive and expressive language processing.

Badcock, Nicholas A.; Bishop, Dorothy V.M.; Hardiman, Mervyn J.; Barry, Johanna G.; Watkins, Kate E.

2012-01-01

42

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.

Takei, Nobuyuki; Nawa, Hiroyuki

2014-01-01

43

SPECT brain perfusion abnormalities in mild or moderate traumatic brain injury.  

PubMed

The purpose of this atlas is to present a review of the literature showing the advantages of SPECT brain perfusion imaging (BPI) in mild or moderate traumatic brain injury (TBI) over other morphologic imaging modalities such as x-ray CT or MRI. The authors also present the technical recommendations for SPECT brain perfusion currently practiced at their center. For the radiopharmaceutical of choice, a comparison between early and delayed images using Tc-99m HMPAO and Tc-99m ECD showed that Tc-99m HMPAO is more stable in the brain with no washout over time. Therefore, the authors feel that Tc-99m HMPAO is preferable to Tc-99m ECD. Recommendations regarding standardizing intravenous injection, the acquisition, processing parameters, and interpretation of scans using a ten grade color scale, and use of the cerebellum as the reference organ are presented. SPECT images of 228 patients (age range, 11 to 88; mean, 40.8 years) with mild or moderate TBI and no significant medical history that interfered with the results of the SPECT BP were reviewed. The etiology of the trauma was in the following order of frequency: motor vehicle accidents (45%) followed by blow to the head (36%) and a fall (19%). Frequency of the symptoms was headache (60.9%), memory problems (27.6%), dizziness (26.7%), and sleep disorders (8.7%). Comparison between patients imaged early (<3 months) versus those imaged delayed (>3 months) from the time of the accident, showed that early imaging detected more lesions (4.2 abnormal lesions per study compared to 2.7 in those imaged more than 3 months after the accident). Of 41 patients who had mild traumatic injury without loss of consciousness and had normal CT, 28 studies were abnormal. Focal areas of hypoperfusion were seen in 77% (176 patients, 612 lesions) of the group of 228 patients. The sites of abnormalities were in the following order: basal ganglia and thalami, 55.2%, frontal lobes, 23.8%, temporal lobes, 13%, parietal, 3.7%, insular and occipital lobes together, 4.6%. PMID:9596157

Abdel-Dayem, H M; Abu-Judeh, H; Kumar, M; Atay, S; Naddaf, S; El-Zeftawy, H; Luo, J Q

1998-05-01

44

Brain White Matter Abnormality in a Newborn Infant with Congenital Adrenal Hyperplasia  

PubMed Central

Several studies have described brain white matter abnormalities on magnetic resonance imaging (MRI) in children and adults with congenital adrenal hyperplasia (CAH), while the brain MRI findings of newborn infants with CAH have not been clarified. We report a newborn boy with CAH who presented brain white matter abnormality on MRI. He was diagnosed as having salt-wasting CAH with a high 17-OHP level at neonatal screening and was initially treated with hydrocortisone at 8 days of age. On day 11 after birth, he had a generalized tonic seizure. No evidence of serum electrolyte abnormalities was observed. Brain MRI revealed white matter abnormalities that consisted of bilateral small diffuse hyperintensities on T1-weighted images with slightly low intensity on T2-weighted images in the watershed area. Several factors associated with brain white matter abnormalities in adults with CAH, such as increasing age, hypertension, diabetes and corticosteroid replacement, were not applicable. Although the cause of the phenomenon in this case is unclear, brain white matter abnormality could be observed in newborn infants with CAH as well as in adult patients.

Kaga, Akimune; Saito-hakoda, Akiko; Uematsu, Mitsugu; Kamimura, Miki; Kanno, Junko; Kure, Shigeo; Fujiwara, Ikuma

2013-01-01

45

Brain amino acid abnormalities in pyruvate carboxylase deficiency  

Microsoft Academic Search

Amino acids were measured in several regions of autopsied brain from an infant who died with congenital lactic acidosis due to pyruvate carboxylase deficiency (McKusick 26615), as well as in cerebrospinal fluid (CSF) and plasma of four living infants with this disorder. Glutamine content was greatly reduced in all brain regions, while glutamic acid and proline contents were elevated. The

T. L. Perry; J. C. Haworth; B. H. Robinson

1985-01-01

46

Brain perfusion studies in the evaluation of acute neurologic abnormalities.  

PubMed

Two categories of single-photon radiopharmaceuticals for brain perfusion exist, nonlipophilic and lipophilic compounds. The former are useful in performing simple flow examinations which today have application primarily in the determination of brain death. The latter also exhibit a parenchymal uptake phase that allows for evaluation of the distribution of blood flow within the brain. The lipophilic radiopharmaceuticals, therefore, have application in the evaluation of patients following catastrophic brain injury and traumatic brain injury (TBI) and in prognosticating the outcome following cerebral vascular accidents. Use of these agents to monitor therapy with thrombolytic agents, although theoretically helpful, is technically difficult due to the need to institute treatment rapidly, without undue delay. PMID:23414828

Zuckier, Lionel S; Sogbein, O O

2013-03-01

47

Structural abnormalities in the dyslexic brain: a meta-analysis of voxel-based morphometry studies.  

PubMed

We used coordinate-based meta-analysis in order to objectively quantify gray matter abnormalities reported in nine Voxel-Based Morphometry studies of developmental dyslexia. Consistently across studies, reduced gray matter volume in dyslexic readers was found in the right superior temporal gyrus and left superior temporal sulcus. These results were related to findings from previous meta-analyses on functional brain abnormalities in dyslexic readers. Convergence of gray matter reduction and reading-related underactivation was found for the left superior temporal sulcus. Recent studies point to the presence of both functional and structural abnormalities in left temporal and occipito-temporal brain regions before reading onset. PMID:22711189

Richlan, Fabio; Kronbichler, Martin; Wimmer, Heinz

2013-11-01

48

Volumetric structural brain abnormalities in men with schizophrenia or antisocial personality disorder  

Microsoft Academic Search

Brain abnormalities are found in association with antisocial personality disorder and schizophrenia, the two mental disorders most implicated in violent behaviour. Structural magnetic resonance imaging was used to investigate the whole brain, cerebellum, temporal lobe, lateral ventricles, caudate nucleus, putamen, thalamus, hippocampus, amygdala and the prefrontal, pre-motor, sensorimotor, occipito-parietal regions in 13 men with antisocial personality disorder, 13 men with

Ian Barkataki; Veena Kumari; Mrigendra Das; Pamela Taylor; Tonmoy Sharma

2006-01-01

49

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.

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

2010-01-01

50

Mutations in LAMB1 cause cobblestone brain malformation without muscular or ocular abnormalities.  

PubMed

Cobblestone brain malformation (COB) is a neuronal migration disorder characterized by protrusions of neurons beyond the first cortical layer at the pial surface of the brain. It is usually seen in association with dystroglycanopathy types of congenital muscular dystrophies (CMDs) and ocular abnormalities termed muscle-eye-brain disease. Here we report homozygous deleterious mutations in LAMB1, encoding laminin subunit beta-1, in two families with autosomal-recessive COB. Affected individuals displayed a constellation of brain malformations including cortical gyral and white-matter signal abnormalities, severe cerebellar dysplasia, brainstem hypoplasia, and occipital encephalocele, but they had less apparent ocular or muscular abnormalities than are typically observed in COB. LAMB1 is localized to the pial basement membrane, suggesting that defective connection between radial glial cells and the pial surface mediated by LAMB1 leads to this malformation. PMID:23472759

Radmanesh, Farid; Caglayan, Ahmet Okay; Silhavy, Jennifer L; Yilmaz, Cahide; Cantagrel, Vincent; Omar, Tarek; Rosti, Ba?ak; Kaymakcalan, Hande; Gabriel, Stacey; Li, Mingfeng; Sestan, Nenad; Bilguvar, Kaya; Dobyns, William B; Zaki, Maha S; Gunel, Murat; Gleeson, Joseph G

2013-03-01

51

Mutations in LAMB1 Cause Cobblestone Brain Malformation without Muscular or Ocular Abnormalities  

PubMed Central

Cobblestone brain malformation (COB) is a neuronal migration disorder characterized by protrusions of neurons beyond the first cortical layer at the pial surface of the brain. It is usually seen in association with dystroglycanopathy types of congenital muscular dystrophies (CMDs) and ocular abnormalities termed muscle-eye-brain disease. Here we report homozygous deleterious mutations in LAMB1, encoding laminin subunit beta-1, in two families with autosomal-recessive COB. Affected individuals displayed a constellation of brain malformations including cortical gyral and white-matter signal abnormalities, severe cerebellar dysplasia, brainstem hypoplasia, and occipital encephalocele, but they had less apparent ocular or muscular abnormalities than are typically observed in COB. LAMB1 is localized to the pial basement membrane, suggesting that defective connection between radial glial cells and the pial surface mediated by LAMB1 leads to this malformation.

Radmanesh, Farid; Caglayan, Ahmet Okay; Silhavy, Jennifer L.; Yilmaz, Cahide; Cantagrel, Vincent; Omar, Tarek; Rosti, Basak; Kaymakcalan, Hande; Gabriel, Stacey; Li, Mingfeng; Sestan, Nenad; Bilguvar, Kaya; Dobyns, William B.; Zaki, Maha S.; Gunel, Murat; Gleeson, Joseph G.

2013-01-01

52

Functional brain networks and abnormal connectivity in the movement disorders.  

PubMed

Clinical manifestations of movement disorders, such as Parkinson's disease (PD) and dystonia, arise from neurophysiological changes within the cortico-striato-pallidothalamocortical (CSPTC) and cerebello-thalamo-cortical (CbTC) circuits. Neuroimaging techniques that probe connectivity within these circuits can be used to understand how these disorders develop as well as identify potential targets for medical and surgical therapies. Indeed, network analysis of (18)F-fluorodeoxyglucose (FDG) positron emission tomography (PET) has identified abnormal metabolic networks associated with the cardinal motor symptoms of PD, such as akinesia and tremor, as well as PD-related cognitive dysfunction. More recent task-based and resting state functional magnetic resonance imaging studies have reproduced several of the altered connectivity patterns identified in these abnormal PD-related networks. A similar network analysis approach in dystonia revealed abnormal disease related metabolic patterns in both manifesting and non-manifesting carriers of dystonia mutations. Other multimodal imaging approaches using magnetic resonance diffusion tensor imaging in patients with primary genetic dystonia suggest abnormal connectivity within the CbTC circuits mediate the clinical manifestations of this inherited neurodevelopmental disorder. Ongoing developments in functional imaging and future studies in early patients are likely to enhance our understanding of these movement disorders and guide novel targets for future therapies. PMID:22206967

Poston, Kathleen L; Eidelberg, David

2012-10-01

53

Functional brain networks and abnormal connectivity in the movement disorders  

PubMed Central

Clinical manifestations of movement disorders, such as Parkinson’s disease (PD) and dystonia, arise from neurophysiological changes within the cortico-striato-pallidothalamocortical (CSPTC) and cerebello-thalamo-cortical (CbTC) circuits. Neuroimaging techniques that probe connectivity within these circuits can be used to understand how these disorders develop as well as identify potential targets for medical and surgical therapies. Indeed, network analysis of 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET) has identified abnormal metabolic networks associated with the cardinal motor symptoms of PD, such as akinesia and tremor, as well as PD-related cognitive dysfunction. More recent task-based and resting state functional magnetic resonance imaging studies have reproduced several of the altered connectivity patterns identified in these abnormal PD-related networks. A similar network analysis approach in dystonia revealed abnormal disease related metabolic patterns in both manifesting and non-manifesting carriers of dystonia mutations. Other multimodal imaging approaches using magnetic resonance diffusion tensor imaging in patients with primary genetic dystonia suggest abnormal connectivity within the CbTC circuits mediate the clinical manifestations of this inherited neurodevelopmental disorder. Ongoing developments in functional imaging and future studies in early patients are likely to enhance our understanding of these movement disorders and guide novel targets for future therapies.

Poston, Kathleen L.; Eidelberg, David

2012-01-01

54

Abnormal upregulation of myelin genes underlies the critical period of myelination in undernourished developing rat brain.  

PubMed

Since myelin gene expression is suppressed during active myelination of the undernourished brain, this study was designed to determine the effects of undernourishment on the upregulation of myelin genes and the relationship between upregulation and the 'critical period' associated with permanent hypomyelination of the brain. Long-Evans rat dams were given either ad libitum or restricted access to rat chow to produce two populations of developing offsprings. The food deprivation schedule was designed to produce a degree of growth retardation comparable to our earlier studies of hypomyelination in undernourished brain. The expression of myelin genes, at various developmental ages, was determined in the forebrains from undernourished and normal, well fed controls by Northern analysis. In well nourished forebrain, proteolipid protein (PLP), myelin associated glycoprotein (MAG), and basic protein (BP) messages began to increase polynomially after day 8 post partum, leading to a rapid accumulation of message during the following several days. In undernourished forebrain, PLP, MAG, and BP messages did not show any increase until day 10, and then increased at a diminished rate as compared to well nourished forebrain. Additionally, the two PLP messages (1.6 kb and 3.2 kb) showed different vulnerabilities to protein-calorie undernourishment, which explains the abnormal ratio of the 3.2 and 1.6 kb forms we previously found in undernourished brain. This study shows a pattern of temporal specificity when the myelin PLP, MAG, and BP genes are synchronously upregulated in the normal forebrain to a high rate of transcription between day 7 to 9, which is several days before the onset of rapid myelination of the brain.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7683238

Royland, J E; Konat, G; Wiggins, R C

1993-04-01

55

Lateralized Tinnitus Studied With Functional Magnetic Resonance Imaging: Abnormal Inferior Colliculus Activation  

Microsoft Academic Search

This paper presents an approach for using functionalmagnetic resonance imaging (fMRI) to investigate the physiology oftinnitus and demonstrates that the approach is effective in revealingtinnitus-related abnormalities in brain function. Our approach as appliedhere included 1) using a masking noise stimulus to change tinnitusloudness and examining the inferior colliculus (IC) for correspondingchanges in activity, 2) separately considering subpopulations with particulartinnitus...

J. R. MELCHER; I. S. SIGALOVSKY; J. J. GUINAN; R. A. LEVINE

2000-01-01

56

Abnormal deposits of chromium in the pathological human brain.  

PubMed Central

Three patients presented with encephalopathies: an undiagnosed degenerative disease of the brain, a degenerative cerebral disease in a patient with a myeloma but without a myelomatous deposit in the CNS and a malignant astrocytoma. Perivascular pallidal deposits (vascular siderosis) containing chromium, phosphorus and calcium plus sometimes traces of other elements were present in the three cases. Such deposits were present in the pallidal parenchyma and around vessels in the cerebellum in one case. Calcium and phosphorus are always present in any CNS calcification but the presence of chromium has not been reported. Chromium and its compounds (ingested, injected or inhaled) are toxic to humans and animals in trace doses. Approximately 900 cases of chromium intoxication have been reported and usually have had dermatological or pulmonary lesions (including cancer) but there is no report of involvement of the CNS. Sublethal doses of chromium nitrate injected intraperitoneally in rats and rabbits results in the presence of chromium in the brain. A thorough investigation was made to find the source of the chromium in these patients. Chromium was found to be present in trace amounts in the radiological contrast agents administered to these patients and in the KCl replacement solution and in mylanta, an antacid, given to one case. The evidence that chromium induced pathological changes in these three brains is circumstantial but shows that chromium can penetrate the human brain. This study indicates that vascular siderosis found in the brains of the majority of middle-aged and elderly humans is not simply an anecdotal pathological curiosity, but that it can serve as a route of entry for toxic products into the brain. Images

Duckett, S

1986-01-01

57

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

58

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

59

Neonatal brain abnormalities and memory and learning outcomes at 7 years in children born very preterm.  

PubMed

Using prospective longitudinal data from 198 very preterm and 70 full term children, this study characterised the memory and learning abilities of very preterm children at 7 years of age in both verbal and visual domains. The relationship between the extent of brain abnormalities on neonatal magnetic resonance imaging (MRI) and memory and learning outcomes at 7 years of age in very preterm children was also investigated. Neonatal MRI scans were qualitatively assessed for global, white-matter, cortical grey-matter, deep grey-matter, and cerebellar abnormalities. Very preterm children performed less well on measures of immediate memory, working memory, long-term memory, and learning compared with term-born controls. Neonatal brain abnormalities, and in particular deep grey-matter abnormality, were associated with poorer memory and learning performance at 7 years in very preterm children. Findings support the importance of cerebral neonatal pathology for predicting later memory and learning function. PMID:23805915

Omizzolo, Cristina; Scratch, Shannon E; Stargatt, Robyn; Kidokoro, Hiroyuki; Thompson, Deanne K; Lee, Katherine J; Cheong, Jeanie; Neil, Jeffrey; Inder, Terrie E; Doyle, Lex W; Anderson, Peter J

2014-08-01

60

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

PubMed

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

61

Brain MRI abnormalities exist in a subset of patients with chronic fatigue syndrome  

Microsoft Academic Search

Presence of MRI brain abnormalities in patients with Chronic Fatigue Syndrome (CFS) was determined and the profile of MRI abnormalities was compared between 39 CFS patients, 18 with (CFS-Psych) and 21 without (CFS-No Psych) a DSM-III-R Axis I psychiatric diagnosis since illness onset, and 19 healthy, sedentary controls (HC). Two neuroradiologists, blind to group membership, separately read the MR films

Gudrun Lange; John DeLuca; Joseph A Maldjian; Huey-Jen Lee; Lana A Tiersky; Benjamin H Natelson

1999-01-01

62

Genetic abnormality predicts benefit from treatment for a rare brain tumor:  

Cancer.gov

A clinical trial has shown that addition of chemotherapy to radiation therapy leads to a near doubling of median survival time in patients with a form of brain tumor (oligodendroglioma) that carries a chromosomal abnormality called the 1p19q co-deletion. This abnormality is characterized by the simultaneous deletion of the short arm of chromosome 1 and long arm of chromosome 19. The presence of the chromosomal abnormality was associated with substantially better prognosis and marked improvements in survival in a treatment program of combined chemotherapy and radiation therapy compared to radiation therapy alone.

63

Ultrasound imaging of fetal brain abnormalities: three essential anatomical levels.  

PubMed

Prenatal ultrasound evaluation of the fetal brain requires documentation of specific structures according to guidelines set by the American College of Radiology and the American Institute of Ultrasound in Medicine. Among these required structures are: cerebellum, cisterna magna, lateral cerebral ventricles, choroid plexus, midline falx, and cavum septum pellucidum. All these structures can be visualized in three crucial planes of imaging that include cisterna magna/cerebellum, cavum septum pellucidum, and ventricular atria. A systematic approach can be achieved by instituting a protocol that includes these three basic levels of imaging of the fetal head. These anatomical levels should be incorporated in daily routine for complete obstetric ultrasound evaluation. PMID:16344747

Angtuaco, Teresita L

2005-12-01

64

Abnormal oscillatory brain dynamics in schizophrenia: a sign of deviant communication in neural network?  

PubMed Central

Background Slow waves in the delta (0.5–4 Hz) frequency range are indications of normal activity in sleep. In neurological disorders, focal electric and magnetic slow wave activity is generated in the vicinity of structural brain lesions. Initial studies, including our own, suggest that the distribution of the focal concentration of generators of slow waves (dipole density in the delta frequency band) also distinguishes patients with psychiatric disorders such as schizophrenia, affective disorders, and posttraumatic stress disorder. Methods The present study examined the distribution of focal slow wave activity (ASWA: abnormal slow wave activity) in116 healthy subjects, 76 inpatients with schizophrenic or schizoaffective diagnoses and 42 inpatients with affective (ICD-10: F3) or neurotic/reactive (F4) diagnoses using a newly refined measure of dipole density. Based on 5-min resting magnetoencephalogram (MEG), sources of activity in the 1–4 Hz frequency band were determined by equivalent dipole fitting in anatomically defined cortical regions. Results Compared to healthy subjects the schizophrenia sample was characterized by significantly more intense slow wave activity, with maxima in frontal and central areas. In contrast, affective disorder patients exhibited less slow wave generators mainly in frontal and central regions when compared to healthy subjects and schizophrenia patients. In both samples, frontal ASWA were related to affective symptoms. Conclusion In schizophrenic patients, the regions of ASWA correspond to those identified for gray matter loss. This suggests that ASWA might be evaluated as a measure of altered neuronal network architecture and communication, which may mediate psychopathological signs.

Rockstroh, Brigitte S; Wienbruch, Christian; Ray, William J; Elbert, Thomas

2007-01-01

65

Migraine With Aura and Brain Magnetic Resonance Imaging Abnormalities in Patients With CADASIL  

Microsoft Academic Search

Background:Migrainewithaura(MA)isoneoftheclini- cal hallmarks of CADASIL (cerebral autosomal domi- nant arteriopathy with subcortical infarcts and leukoen- cephalopathy), a small vessel disease of the brain caused by mutations in the NOTCH3 gene, but its exact mecha- nisms are unknown. Objectives:TodescribethepatternsofMAinCADASIL andtocomparebrainmagneticresonancesignalabnormali- ties between CADASIL patients with and without MA. Design: Comparison of brain magnetic resonance sig- nal abnormalities between cases and controls.

Katayoun Vahedi; Hugues Chabriat; Claude Levy; Anne Joutel; Elisabeth Tournier-Lasserve; Marie-Germaine Bousser

2004-01-01

66

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.

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

67

Sensor-Based Abnormal Human-Activity Detection  

Microsoft Academic Search

With the availability of affordable sensors and sensor networks, sensor-based human-activity recognition has attracted much attention in artificial intelligence and ubiquitous computing. In this paper, we present a novel two-phase approach for detecting abnormal activities based on wireless sensors attached to a human body. Detecting abnormal activities is a particularly important task in security monitoring and healthcare applications of sensor

Jie Yin; Qiang Yang; Jeffrey Junfeng Pan

2008-01-01

68

Kinetic Models of Brain Activity  

Microsoft Academic Search

Brain imaging sciences, like neurosciences in general, have predominantly been an empirical endeavour. This paper argues that\\u000a the maturation of “kinetic models” of large-scale neuronal activity will provide a unifying theory to underpin brain imaging\\u000a sciences. In particular, this framework will provide a means of unifying data from different imaging modalities, afford a\\u000a direct link with cognitive theories of brain

Michael Breakspear; Stuart Knock

2008-01-01

69

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.

2014-01-01

70

Intermittent rhythmic delta activity (IRDA) morphology cannot distinguish between focal and diffuse brain disturbances.  

PubMed

IRDA (intermittent rhythmic delta activity) is an abnormal generalized EEG pattern that is not specific to any single etiology and can occur with diffuse or focal cerebral disturbances. To determine whether different electrographic features of IRDA and associated EEG findings can differentiate underlying focal from diffuse brain disturbances, we performed a blind analysis of 58 consecutive EEGs with an IRDA pattern, recorded from 1993 until 1996, in which we evaluated posterior background activity, focal slowing and IRDA characteristics (frequency, distribution, duration, symmetry and abundance). The clinical diagnosis, state of consciousness and CT brain findings were retrieved from the patients' hospital records. There were 58 patients (33 females; mean age, 58+/-21 years). Twelve (21%) had only focal brain lesions, while 46 (79%) had diffuse brain abnormalities, (15 diffuse structural, 19 metabolic abnormalities, 12 postictal). Normal consciousness and focal EEG slowing were more frequent in patients with focal abnormalities, however, this was not statistically significant. Of the patients with focal abnormality, 11 (92%) had normal posterior background activity either bilaterally (n=4) or contralateral to the focal lesion (n=7). Bilaterally normal posterior background activity was observed in about 30% in both groups. Bilaterally abnormal posterior background activity was apparent in one patient (8%) with focal brain lesion and in 31 patients (67%) with diffuse brain abnormalities (P<0.0001). There were no significant differences in IRDA electrographic features between the focal group and the group with diffuse brain disturbances. We conclude that IRDA morphology cannot distinguish between focal and diffuse brain abnormalities. PMID:10385048

Neufeld, M Y; Chistik, V; Chapman, J; Korczyn, A D

1999-03-15

71

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. © 2014 Wiley Periodicals, Inc. 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

72

Abnormal corticospinal excitability in traumatic diffuse axonal brain injury.  

PubMed

This study aimed to investigate the cortical motor excitability characteristics in diffuse axonal injury (DAI) due to severe traumatic brain injury (TBI). A variety of excitatory and inhibitory transcranial magnetic stimulation (TMS) paradigms were applied to primary motor cortices of 17 patients and 11 healthy controls. The parameters of testing included resting motor threshold (MT), motor evoked potential (MEP) area under the curve, input-output curves, MEP variability, and silent period (SP) duration. The patient group overall revealed a higher MT, smaller MEP areas, and narrower recruitment curves compared to normal controls (p < 0.05). The alterations in excitability were more pronounced with an increase in DAI severity (p < 0.005) and the presence of motor impairment (p < 0.05), while co-existence of focal lesions did not affect the degree of MEP changes. MEP variability was significantly lower in the group with motor impairment only (p < 0.05). The intracortical inhibition, as revealed by SP duration, did not exhibit any significant differences in any of the patient groups. In conclusion, our findings expand the concept that impairment of the excitatory and inhibitory phenomena in the motor cortex does not proceed in parallel and demonstrate distinct patterns of aberrations in TBI. Furthermore, these data suggest that alterations in the corticospinal excitatory mechanisms are determined predominantly by the severity of DAI, and show a significant relationship with clinical motor dysfunction following severe trauma diffusely affecting the motor cortical connections. In severe TBI, motor and functional recovery might be linked to restitution of normal corticospinal mechanisms, indexed by normalization of the cortical excitability parameters. PMID:19604100

Bernabeu, Montse; Demirtas-Tatlidede, Asli; Opisso, Eloy; Lopez, Raquel; Tormos, Jose M; Pascual-Leone, Alvaro

2009-12-01

73

Abnormal Corticospinal Excitability in Traumatic Diffuse Axonal Brain Injury  

PubMed Central

Abstract This study aimed to investigate the cortical motor excitability characteristics in diffuse axonal injury (DAI) due to severe traumatic brain injury (TBI). A variety of excitatory and inhibitory transcranial magnetic stimulation (TMS) paradigms were applied to primary motor cortices of 17 patients and 11 healthy controls. The parameters of testing included resting motor threshold (MT), motor evoked potential (MEP) area under the curve, input-output curves, MEP variability, and silent period (SP) duration. The patient group overall revealed a higher MT, smaller MEP areas, and narrower recruitment curves compared to normal controls (p?

Bernabeu, Montse; Demirtas-Tatlidede, Asli; Opisso, Eloy; Lopez, Raquel; Tormos, Jose M?

2009-01-01

74

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

75

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

76

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.

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

2014-01-01

77

A mechanical model predicts morphological abnormalities in the developing human brain  

PubMed Central

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

2014-01-01

78

A mechanical model predicts morphological abnormalities in the developing human brain.  

PubMed

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. PMID:25008163

Budday, Silvia; Raybaud, Charles; Kuhl, Ellen

2014-01-01

79

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.

Dienel, Gerald A

2012-01-01

80

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.

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

81

Structural brain abnormalities among relatives of patients with schizophrenia: implications for linkage studies  

Microsoft Academic Search

Several studies suggest that the nonschizophrenic relatives of schizophrenic patients exhibit structural brain abnormalities that may be manifestations of genes that predispose to schizophrenia. In this work, we examine the utility of such measures for linkage analyses. Subjects were 45 nonpsychotic first-degree adult relatives of schizophrenic patients and 48 normal controls. Sixty contiguous 3-mm coronal, T1-weighted 3D magnetic resonance images

Stephen V. Faraone; Larry J. Seidman; William S. Kremen; David Kennedy; Nikos Makris; Verne S. Caviness; Jill Goldstein; Ming T. Tsuang

2003-01-01

82

Polysubstance and Alcohol Dependence: Unique Abnormalities of Magnetic Resonance-Derived Brain Metabolite Levels  

PubMed Central

BACKGROUND Although comorbid substance misuse is common in alcohol dependence, and polysubstance abusers (PSU) represent the largest group of individuals seeking treatment for drug abuse today, we know little about potential brain abnormalities in this population. Brain magnetic resonance spectroscopy studies of mono-substance use disorders (e.g., alcohol or cocaine) reveal abnormal levels of cortical metabolites (reflecting neuronal integrity, cell membrane turnover/synthesis, cellular bioenergetics, gliosis) and altered concentrations of glutamate and ?-aminobutyric acid (GABA). The concurrent misuse of several substances may have unique and different effects on brain biology and function compared to any mono-substance misuse. METHODS High field brain magnetic resonance spectroscopy at 4 Tesla and neurocognitive testing were performed at one month of abstinence in 40 alcohol dependent individuals (ALC), 28 alcohol dependent PSU and 16 drug-free controls. Absolute metabolite concentrations were calculated in anterior cingulate (ACC), parieto-occipital (POC) and dorsolateral prefrontal cortices (DLPFC). RESULTS Compared to ALC, PSU demonstrated significant metabolic abnormalities in the DLPFC and strong trends to lower GABA in the ACC. Metabolite levels in ALC and light drinking controls were statistically equivalent. Within PSU, lower DLPFC GABA levels related to greater cocaine consumption. Several cortical metabolite concentrations were associated with cognitive performance. CONCLUSIONS While metabolite concentrations in ALC at one month of abstinence were largely normal, PSU showed persistent and functionally significant metabolic abnormalities, primarily in the DLPFC. Our results point to specific metabolic deficits as biomarkers in polysubstance misuse and as targets for pharmacological and behavioral PSU-specific treatment.

Abe, Christoph; Mon, Anderson; Durazzo, Timothy C.; Pennington, David L.; Schmidt, Thomas P.; Meyerhoff, Dieter J.

2012-01-01

83

Abnormal Error Monitoring in Math-Anxious Individuals: Evidence from Error-Related Brain Potentials  

PubMed Central

This study used event-related brain potentials to investigate whether math anxiety is related to abnormal error monitoring processing. Seventeen high math-anxious (HMA) and seventeen low math-anxious (LMA) individuals were presented with a numerical and a classical Stroop task. Groups did not differ in terms of trait or state anxiety. We found enhanced error-related negativity (ERN) in the HMA group when subjects committed an error on the numerical Stroop task, but not on the classical Stroop task. Groups did not differ in terms of the correct-related negativity component (CRN), the error positivity component (Pe), classical behavioral measures or post-error measures. The amplitude of the ERN was negatively related to participants’ math anxiety scores, showing a more negative amplitude as the score increased. Moreover, using standardized low resolution electromagnetic tomography (sLORETA) we found greater activation of the insula in errors on a numerical task as compared to errors in a non-numerical task only for the HMA group. The results were interpreted according to the motivational significance theory of the ERN.

Suarez-Pellicioni, Macarena; Nunez-Pena, Maria Isabel; Colome, Angels

2013-01-01

84

Influence of History of Brain Disease or Brain Trauma on Psychopathological Abnormality in Young Male in Korea : Analysis of Multiphasic Personal Inventory Test  

PubMed Central

Objective The purpose of this study is to confirm whether brain disease or brain trauma actually affect psychopathology in young male group in Korea. Methods The authors manually reviewed the result of Korean military multiphasic personal inventory (KMPI) in the examination of conscription in Korea from January 2008 to May 2010. There were total 237 young males in this review. Normal volunteers group (n=150) was composed of those who do not have history of brain disease or brain trauma. Brain disease group (n=33) was consisted of those with history of brain disease. Brain trauma group (n=54) was consisted of those with history of brain trauma. The results of KMPI in each group were compared. Results Abnormal results of KMPI were found in both brain disease and trauma groups. In the brain disease group, higher tendencies of faking bad response, anxiety, depression, somatization, personality disorder, schizophrenic and paranoid psychopathy was observed and compared to the normal volunteers group. In the brain trauma group, higher tendencies of faking-good, depression, somatization and personality disorder was observed and compared to the normal volunteers group. Conclusion Young male with history of brain disease or brain trauma may have higher tendencies to have abnormal results of multiphasic personal inventory test compared to young male without history of brain disease or brain trauma, suggesting that damaged brain may cause psychopathology in young male group in Korea.

Paik, Ho Kyu; Oh, Chang-Hyun; Choi, Kang; Kim, Chul-Eung; Yoon, Seung Hwan

2011-01-01

85

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

86

Abnormalities in Na+/H+ antiporter activity in diabetic nephropathy.  

PubMed

In hypertensive humans and the spontaneously hypertensive rat, increased cellular Na+/H+ antiport activity has been demonstrated in leukocytes, platelets, skeletal muscle, and vascular smooth muscle cells. This membrane abnormality may be associated with medial thickening of resistance vessels. A similar membrane transport abnormality has also been demonstrated in leukocytes and fibroblasts from type 1 diabetic patients with nephropathy. This membrane transport marker of hypertension may indicate a predisposition to essential hypertension in such patients and may lead to diabetic nephropathy, possibly from mesangial expansion. PMID:1333834

Ng, L L; Davies, J E

1992-10-01

87

Sodium sulfide prevents water diffusion abnormality in the brain and improves long term outcome after cardiac arrest in mice  

PubMed Central

Aim of the study Sudden cardiac arrest (CA) is one of the leading causes of death worldwide. Previously we demonstrated that administration of sodium sulfide (Na2S), a hydrogen sulfide (H2S) donor, markedly improved the neurological outcome and survival rate at 24h after CA and cardiopulmonary resuscitation (CPR) in mice. In this study, we sought to elucidate the mechanism responsible for the neuroprotective effects of Na2S and its impact on the long-term survival after CA/CPR in mice. Methods Adult male mice were subjected to potassium-induced CA for 7.5 min at 37°C whereupon CPR was performed with chest compression and mechanical ventilation. Mice received Na2S (0.55 mg/kg i.v.) or vehicle 1 min before CPR. Results Mice that were subjected to CA/CPR and received vehicle exhibited a poor 10-day survival rate (4/12) and depressed neurological function. Cardiac arrest and CPR induced abnormal water diffusion in the vulnerable regions of the brain, as demonstrated by hyperintense diffusion-weighted imaging (DWI) 24h after CA/CPR. Extent of hyperintense DWI was associated with matrix metalloproteinase 9 (MMP-9) activation, worse neurological outcomes, and poor survival rate at 10 days after CA/CPR. Administration of Na2S prevented the development of abnormal water diffusion and MMP-9 activation and markedly improved neurological function and long-term survival (9/12, P<0.05 vs. vehicle) after CA/CPR. Conclusion These results suggest that administration of Na2S 1 min before CPR improves neurological function and survival rate at 10 days after CA/CPR by preventing water diffusion abnormality in the brain potentially via inhibiting MMP-9 activation early after resuscitation.

Kida, Kotaro; Minamishima, Shizuka; Wang, Huifang; Ren, JiaQian; Yigitkanli, Kazim; Nozari, Ala; Mandeville, Joseph B.; Liu, Philip K.; Liu, Christina H.; Ichinose, Fumito

2012-01-01

88

Abnormal functional brain asymmetry in depression: evidence of biologic commonality between major depression and dysthymia.  

PubMed

Prior studies have found abnormalities of functional brain asymmetry in patients having a major depressive disorder (MDD). This study aimed to replicate findings of reduced right hemisphere advantage for perceiving dichotic complex tones in depressed patients, and to determine whether patients having "pure" dysthymia show the same abnormality of perceptual asymmetry as MDD. It also examined gender differences in lateralization, and the extent to which abnormalities of perceptual asymmetry in depressed patients are dependent on gender. Unmedicated patients having either a MDD (n=96) or "pure" dysthymic disorder (n=42) and healthy controls (n=114) were tested on dichotic fused-words and complex-tone tests. Patient and control groups differed in right hemisphere advantage for complex tones, but not left hemisphere advantage for words. Reduced right hemisphere advantage for tones was equally present in MDD and dysthymia, but was more evident among depressed men than depressed women. Also, healthy men had greater hemispheric asymmetry than healthy women for both words and tones, whereas this gender difference was not seen for depressed patients. Dysthymia and MDD share a common abnormality of hemispheric asymmetry for dichotic listening. PMID:22397909

Bruder, Gerard E; Stewart, Jonathan W; Hellerstein, David; Alvarenga, Jorge E; Alschuler, Daniel; McGrath, Patrick J

2012-04-30

89

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.

Roussotte, Florence; Soderberg, Lindsay

2010-01-01

90

Cerebrovascular risk factors and brain microstructural abnormalities on diffusion tensor images in HIV-infected individuals  

PubMed Central

HIV-associated neurocognitive disorder remains prevalent in HIV-infected individuals despite effective antiretroviral therapy. As these individuals age, comorbid cerebrovascular disease will likely impact cognitive function. Effective tools to study this impact are needed. This study used diffusion tensor imaging (DTI) to characterize brain microstructural changes in HIV-infected individuals with and without cerebrovascular risk factors. Diffusion-weighted MRIs were obtained in 22 HIV-infected subjects aged 50 years or older (mean age = 58 years, standard deviation = 6 years; 19 males, three females). Tensors were calculated to obtain fractional anisotropy (FA) and mean diffusivity (MD) maps. Statistical comparisons accounting for multiple comparisons were made between groups with and without cerebrovascular risk factors. Abnormal glucose metabolism (i.e., impaired fasting glucose, impaired glucose tolerance, or diabetes mellitus) was associated with significantly higher MD (false discovery rate (FDR) critical p value = 0.008) and lower FA FDR critical p value = 0.002) in the caudate and lower FA in the hippocampus (FDR critical p value = 0.004). Pearson correlations were performed between DTI measures in the caudate and hippocampus and age- and education-adjusted composite scores of global cognitive function, memory, and psychomotor speed. There were no detectable correlations between the neuroimaging measures and measures of cognition. In summary, we demonstrate that brain microstructural abnormalities are associated with abnormal glucose metabolism in the caudate and hippocampus of HIV-infected individuals. Deep gray matter structures and the hippocampus may be vulnerable in subjects with comorbid abnormal glucose metabolism, but our results should be confirmed in further studies.

Jahanshad, Neda; McMurtray, Aaron; Kallianpur, Kalpana J.; Chow, Dominic C.; Valcour, Victor G.; Paul, Robert H.; Marotz, Liron; Thompson, Paul M.; Shikuma, Cecilia M.

2012-01-01

91

Cerebrovascular risk factors and brain microstructural abnormalities on diffusion tensor images in HIV-infected individuals.  

PubMed

HIV-associated neurocognitive disorder remains prevalent in HIV-infected individuals despite effective antiretroviral therapy. As these individuals age, comorbid cerebrovascular disease will likely impact cognitive function. Effective tools to study this impact are needed. This study used diffusion tensor imaging (DTI) to characterize brain microstructural changes in HIV-infected individuals with and without cerebrovascular risk factors. Diffusion-weighted MRIs were obtained in 22 HIV-infected subjects aged 50 years or older (mean age?=?58 years, standard deviation?=?6 years; 19 males, three females). Tensors were calculated to obtain fractional anisotropy (FA) and mean diffusivity (MD) maps. Statistical comparisons accounting for multiple comparisons were made between groups with and without cerebrovascular risk factors. Abnormal glucose metabolism (i.e., impaired fasting glucose, impaired glucose tolerance, or diabetes mellitus) was associated with significantly higher MD (false discovery rate (FDR) critical p value?=?0.008) and lower FA (FDR critical p value?=?0.002) in the caudate and lower FA in the hippocampus (FDR critical p value?=?0.004). Pearson correlations were performed between DTI measures in the caudate and hippocampus and age- and education-adjusted composite scores of global cognitive function, memory, and psychomotor speed. There were no detectable correlations between the neuroimaging measures and measures of cognition. In summary, we demonstrate that brain microstructural abnormalities are associated with abnormal glucose metabolism in the caudate and hippocampus of HIV-infected individuals. Deep gray matter structures and the hippocampus may be vulnerable in subjects with comorbid abnormal glucose metabolism, but our results should be confirmed in further studies. PMID:22585287

Nakamoto, Beau K; Jahanshad, Neda; McMurtray, Aaron; Kallianpur, Kalpana J; Chow, Dominic C; Valcour, Victor G; Paul, Robert H; Marotz, Liron; Thompson, Paul M; Shikuma, Cecilia M

2012-08-01

92

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.

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

2014-01-01

93

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.

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

2013-01-01

94

Rapid Morphological Brain Abnormalities during Acute Methamphetamine Intoxication in the Rat. An Experimental study using Light and Electron Microscopy  

PubMed Central

This study describes morphological abnormalities of brain cells during acute methamphetamine (METH) intoxication in the rat and demonstrates the role of hyperthermia, disruption of the blood-brain barrier (BBB) and edema in their development. Rats with chronically implanted brain, muscle and skin temperature probes and an intravenous (iv) catheter were exposed to METH (9 mg/kg) at standard (23°C) and warm (29°C) ambient temperatures, allowing for the observation of hyperthermia ranging from mild to pathological levels (38–42°C). When brain temperature peaked or reached a level suggestive of possible lethality (>41.5°C), rats were injected with Evans blue (EB), rapidly anesthetized, perfused, and their brains were taken for further analyses. Four brain areas (cortex, hippocampus, thalamus and hypothalamus) were analyzed for EB extravasation, water and electrolyte (Na+, K+, Cl?) contents, immunostained for albumin and glial fibrillary acidic protein, and examined for neuronal, glial and axonal alterations using standard light and electron microscopy. These examinations revealed profound abnormalities in neuronal, glial, and endothelial cells, which were stronger with METH administered at 29°C than 23°C and tightly correlated with brain and body hyperthermia. These changes had some structural specificity, but in each structure they tightly correlated with increases in EB levels, the numbers of albumin-positive cells, and water and ion contents, suggesting leakage of the BBB, acutely developing brain edema, and serious shifts in brain ion homeostasis as leading factors underlying brain abnormalities. While most of these acute structural and functional abnormalities appear to be reversible, they could trigger subsequent cellular alterations in the brain and accelerate neurodegeneration—the most dangerous complication of chronic amphetamine-like drug abuse.

Sharma, Hari S.; Kiyatkin, Eugene A.

2009-01-01

95

Abnormalities of functional brain networks in pathological gambling: a graph-theoretical approach  

PubMed Central

Functional neuroimaging studies of pathological gambling (PG) demonstrate alterations in frontal and subcortical regions of the mesolimbic reward system. However, most investigations were performed using tasks involving reward processing or executive functions. Little is known about brain network abnormalities during task-free resting state in PG. In the present study, graph-theoretical methods were used to investigate network properties of resting state functional magnetic resonance imaging data in PG. We compared 19 patients with PG to 19 healthy controls (HCs) using the Graph Analysis Toolbox (GAT). None of the examined global metrics differed between groups. At the nodal level, pathological gambler showed a reduced clustering coefficient in the left paracingulate cortex and the left juxtapositional lobe (supplementary motor area, SMA), reduced local efficiency in the left SMA, as well as an increased node betweenness for the left and right paracingulate cortex and the left SMA. At an uncorrected threshold level, the node betweenness in the left inferior frontal gyrus was decreased and increased in the caudate. Additionally, increased functional connectivity between fronto-striatal regions and within frontal regions has also been found for the gambling patients. These findings suggest that regions associated with the reward system demonstrate reduced segregation but enhanced integration while regions associated with executive functions demonstrate reduced integration. The present study makes evident that PG is also associated with abnormalities in the topological network structure of the brain during rest. Since alterations in PG cannot be explained by direct effects of abused substances on the brain, these findings will be of relevance for understanding functional connectivity in other addictive disorders.

Tschernegg, Melanie; Crone, Julia S.; Eigenberger, Tina; Schwartenbeck, Philipp; Fauth-Buhler, Mira; Lemenager, Tagrid; Mann, Karl; Thon, Natasha; Wurst, Friedrich M.; Kronbichler, Martin

2013-01-01

96

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; Edward Wexler, Bruce

2014-06-30

97

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.

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

2013-01-01

98

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

PubMed

Id2 is a helix-loop-helix 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 neural stem cells (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-overexpressing 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 overexpression 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, Hee Jung; Hong, Mingi; Bronson, Roderick T; Israel, Mark A; Frankel, Wayne N; Yun, Kyuson

2013-05-01

99

Abnormal brain response to cholinergic challenge in chronic encephalopathy from the 1991 Gulf War.  

PubMed

Several case definitions of chronic illness in veterans of the 1991 Persian Gulf War have been linked epidemiologically with environmental exposure to cholinesterase-inhibiting chemicals, which cause chronic changes in cholinergic receptors in animal models. Twenty-one chronically ill Gulf War veterans (5 with symptom complex 1, 11 with complex 2, and 5 with complex 3) and 17 age-, sex- and education-matched controls, underwent an 99mTc-HMPAO-SPECT brain scan following infusion of saline and >48 h later a second scan following infusion of physostigmine in saline. From each SPECT image mean normalized regional cerebral blood flow (nrCBF) from 39 small blocks of correlated voxels were extracted with geostatistical spatial modeling from eight deep gray matter structures in each hemisphere. Baseline nrCBF in symptom complex 2 was lower than controls throughout deep structures. The change in nrCBF after physostigmine (challenge minus baseline) was negative in complexes 1 and 3 and controls but positive in complex 2 in some structures. Since effects were opposite in different groups, no finding typified the entire patient sample. A hold-out discriminant model of nrCBF from 17 deep brain blocks predicted membership in the clinical groups with sensitivity of 0.95 and specificity of 0.82. Gulf War-associated chronic encephalopathy in a subset of veterans may be due to neuronal dysfunction, including abnormal cholinergic response, in deep brain structures. PMID:19230625

Haley, Robert W; Spence, Jeffrey S; Carmack, Patrick S; Gunst, Richard F; Schucany, William R; Petty, Frederick; Devous, Michael D; Bonte, Frederick J; Trivedi, Madhukar H

2009-03-31

100

Multicenter Study of Brain Volume Abnormalities in Children and Adolescent-Onset Psychosis  

PubMed Central

The goal of the study is to determine the extent of structural brain abnormalities in a multicenter sample of children and adolescents with a recent-onset first episode of psychosis (FEP), compared with a sample of healthy controls. Total brain and lobar volumes and those of gray matter (GM), white matter, and cerebrospinal fluid (CSF) were measured in 92 patients with a FEP and in 94 controls, matched for age, gender, and years of education. Male patients (n = 64) showed several significant differences when compared with controls (n = 61). GM volume in male patients was reduced in the whole brain and in frontal and parietal lobes compared with controls. Total CSF volume and frontal, temporal, and right parietal CSF volumes were also increased in male patients. Within patients, those with a further diagnosis of “schizophrenia” or “other psychosis” showed a pattern similar to the group of all patients relative to controls. However, bipolar patients showed fewer differences relative to controls. In female patients, only the schizophrenia group showed differences relative to controls, in frontal CSF. GM deficit in male patients with a first episode correlated with negative symptoms. Our study suggests that at least part of the GM deficit in children and adolescent-onset schizophrenia and in other psychosis occurs before onset of the first positive symptoms and that, contrary to what has been shown in children-onset schizophrenia, frontal GM deficits are probably present from the first appearance of positive symptoms in children and adolescents.

Reig, Santiago; Parellada, Mara; Castro-Fornieles, Josefina; Janssen, Joost; Moreno, Dolores; Baeza, Inmaculada; Bargallo, Nuria; Gonzalez-Pinto, Ana; Graell, Montserrat; Ortuno, Felipe; Otero, Soraya; Arango, Celso; Desco, Manuel

2011-01-01

101

Abnormal functional brain connectivity and personality traits in myotonic dystrophy type 1.  

PubMed

IMPORTANCE Myotonic dystrophy type 1 (DM1), the most common muscular dystrophy observed in adults, is a genetic multisystem disorder affecting several other organs besides skeletal muscle, including the brain. Cognitive and personality abnormalities have been reported; however, no studies have investigated brain functional networks and their relationship with personality traits/disorders in patients with DM1. OBJECTIVE To use resting-state functional magnetic resonance imaging to assess the potential relationship between personality traits/disorders and changes to functional connectivity within the default mode network (DMN) in patients with DM1. DESIGN, SETTING, AND PARTICIPANTS We enrolled 27 patients with genetically confirmed DM1 and 16 matched healthy control individuals. Patients underwent personality assessment using clinical interview and Minnesota Multiphasic Personality Inventory-2 administration; all participants underwent resting-state functional magnetic resonance imaging. Investigations were conducted at the Istituto di Ricovero e Cura a Carattere Scientifico Santa Lucia Foundation, Catholic University of Sacred Heart, and Azienda Ospedaliera San Camillo Forlanini. INTERVENTION Resting-state functional magnetic resonance imaging. MAIN OUTCOMES AND MEASURES Measures of personality traits in patients and changes in functional connectivity within the DMN in patients and controls. Changes in functional connectivity and atypical personality traits in patients were correlated. RESULTS We combined results obtained from the Minnesota Multiphasic Personality Inventory-2 and clinical interview to identify a continuum of atypical personality profiles ranging from schizotypal personality traits to paranoid personality disorder within our DM1 patients. We also demonstrated an increase in functional connectivity in the bilateral posterior cingulate and left parietal DMN nodes in DM1 patients compared with controls. Moreover, patients with DM1 showed strong associations between DMN functional connectivity and schizotypal-paranoid traits. CONCLUSIONS AND RELEVANCE Our findings provide novel biological evidence that DM1 is a clinical condition that also involves an alteration of functional connectivity of the brain. We speculate that these functional brain abnormalities, similarly to frank psychiatric disorders, may account for the atypical personality traits observed in patients with DM1. PMID:24664202

Serra, Laura; Silvestri, Gabriella; Petrucci, Antonio; Basile, Barbara; Masciullo, Marcella; Makovac, Elena; Torso, Mario; Spanò, Barbara; Mastropasqua, Chiara; Harrison, Neil A; Bianchi, Maria L E; Giacanelli, Manlio; Caltagirone, Carlo; Cercignani, Mara; Bozzali, Marco

2014-05-01

102

Functional brain abnormalities localized in 55 chronic tinnitus patients: fusion of SPECT coincidence imaging and MRI  

Microsoft Academic Search

Tinnitus is often defined as the perception of sounds or noise in the absence of any external auditory stimuli. The pathophysiology of subjective idiopathic tinnitus remains unclear. The aim of this study was to investigate the functional brain activities and possible involved cerebral areas in subjective idiopathic tinnitus patients by means of single photon emission computerized tomography (SPECT) coincidence imaging,

Mohammad Farhadi; Saeid Mahmoudian; Fariba Saddadi; Ali Reza Karimian; Mohammad Mirzaee; Majid Ahmadizadeh; Khosro Ghasemikian; Saeid Gholami; Esmaeel Ghoreyshi; Saeid Beyty; Ahmadreza Shamshiri; Sedighe Madani; Valery Bakaev; Seddighe Moradkhani; Gholamreza Raeisali

2010-01-01

103

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

104

Intracranial EEG surface renderings: new insights into normal and abnormal brain function.  

PubMed

Intracranial electro-encephalography (icEEG) provides a unique opportunity to record directly from the human brain and is clinically important for planning epilepsy surgery. However, traditional visual analysis of icEEG is often challenging. The typical simultaneous display of multiple electrode channels can prevent an in-depth understanding of the spatial-time course of brain activity. In recent decades, advances in the field of neuroimaging have provided powerful new tools for the analysis and display of signals in the brain. These methods can now be applied to icEEG to map electrical signal information onto a three-dimensional rendering of a patient's cortex and graphically observe the changes in voltage over time. This approach provides rapid visualization of seizures and normal activity propagating over the brain surface and can also illustrate subtle changes that might be missed by traditional icEEG analysis. In addition, the direct mapping of signal information onto accurate anatomical structures can assist in the precise targeting of sites for epilepsy surgery and help correlate electrical activity with behavior. Bringing icEEG data into a standardized anatomical space will also enable neuroimaging methods of statistical analysis to be applied. As new technologies lead to a dramatic increase in the rate of data acquisition, these novel visualization and analysis techniques will play an important role in processing the valuable information obtained through icEEG. PMID:22653695

Youngblood, Mark W; Han, Xiao; Farooque, Pue; Jhun, Stephen; Bai, Xiaoxiao; Yoo, Ji Yeoun; Lee, Hyang Woon; Blumenfeld, Hal

2013-06-01

105

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.

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

106

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

107

Brain Activity and Human Unilateral Chewing  

PubMed Central

Brain mechanisms underlying mastication have been studied in non-human mammals but less so in humans. We used functional magnetic resonance imaging (fMRI) to evaluate brain activity in humans during gum chewing. Chewing was associated with activations in the cerebellum, motor cortex and caudate, cingulate, and brainstem. We also divided the 25-second chew-blocks into 5 segments of equal 5-second durations and evaluated activations within and between each of the 5 segments. This analysis revealed activation clusters unique to the initial segment, which may indicate brain regions involved with initiating chewing. Several clusters were uniquely activated during the last segment as well, which may represent brain regions involved with anticipatory or motor events associated with the end of the chew-block. In conclusion, this study provided evidence for specific brain areas associated with chewing in humans and demonstrated that brain activation patterns may dynamically change over the course of chewing sequences.

Quintero, A.; Ichesco, E.; Myers, C.; Schutt, R.; Gerstner, G.E.

2013-01-01

108

Structural brain abnormalities in borderline personality disorder: A voxel-based morphometry study  

PubMed Central

Imaging studies using ROI morphometry and PET have contributed to our understanding of structural and functional abnormalities in BPD; however, both methods have practical limitations to their usefulness for exploratory studies of brain-behavior relationships. We used voxel based morphometry (VBM) in 34 subjects with BPD and 30 healthy controls (HC) to study effects of diagnosis, gender, childhood sexual abuse, depressed mood, impulsivity and aggression on group differences. VBM is a computer-based method for whole brain analysis that combines the advantages of a functional study with a structural method. The BPD subjects, diagnosed with the Diagnostic Interview for Borderline Patients and the International Personality Disorders Examination, were compared with 30 HC, with age and gender covaried. Analyses were repeated separately by gender and, in women, by histories of childhood sexual abuse. Depressed mood, impulsivity, and aggression were covaried in separate analyses. Compared with HC, BPD subjects had significant bilateral reductions in gray matter concentrations in ventral cingulate gyrus and several regions of the medial temporal lobe, including the hippocampus, amygdala, parahippocampal gyrus, and uncus. BPD women (and abused BPD women), but not BPD men, had significant reductions in medial temporal lobe, including the amygdala. BPD men, but not BPD women, showed diminished gray matter concentrations in the anterior cingulate gyrus compared with findings HC. Covarying for depressed mood rendered group differences non-significant in the ventral cingulate but had little effect on differences in medial temporal cortex. Covarying for aggression (LHA) had relatively little effect on group differences, while covarying for impulsivity (BIS) rendered all previously noted voxel-level group differences non-significant. Diminished gray matter in the prefrontal cortex and the medial temporal cortex may mediate the dysregulation of impulse and affect in BPD. Group differences varied greatly by gender, levels of depression, and impulsivity. VBM is an efficient method for exploratory study of brain-behavior relationships.

Soloff, Paul; Nutche, Jeffrey; Goradia, Dhruman; Diwadkar, Vaibhav

2012-01-01

109

Brain volumetric abnormalities in patients with anorexia and bulimia nervosa: a voxel-based morphometry study.  

PubMed

Recent studies focussing on neuroimaging features of eating disorders have observed that anorexia nervosa (AN) is characterized by significant grey matter (GM) atrophy in many brain regions, especially in the cerebellum and anterior cingulate cortex. To date, no studies have found GM atrophy in bulimia nervosa (BN) or have directly compared patients with AN and BN. We used voxel-based morphometry (VBM) to characterize brain abnormalities in AN and BN patients, comparing them with each other and with a control group, and correlating brain volume with clinical features. We recruited 17 AN, 13 BN and 14 healthy controls. All subjects underwent high-resolution magnetic resonance imaging (MRI) with a T1-weighted 3D image. VBM analysis was carried out with the FSL-VBM 4.1 tool. We found no global atrophy, but regional GM reduction in AN with respect to controls and BN in the cerebellum, fusiform area, supplementary motor area, and occipital cortex, and in the caudate in BN compared to AN and controls. Both groups of patients had a volumetric increase bilaterally in somatosensory regions with respect to controls, in areas that are typically involved in the sensory-motor integration of body stimuli and in mental representation of the body image. Our VBM study documented, for the first time in BN patients, the presence of volumetric alterations and replicated previous findings in AN patients. We evidenced morphological differences between AN and BN, demonstrating in the latter atrophy of the caudate nucleus, a region involved in reward mechanisms and processes of self-regulation, perhaps involved in the genesis of the binge-eating behaviors of this disorder. PMID:23856299

Amianto, Federico; Caroppo, Paola; D'Agata, Federico; Spalatro, Angela; Lavagnino, Luca; Caglio, Marcella; Righi, Dorico; Bergui, Mauro; Abbate-Daga, Giovanni; Rigardetto, Roberto; Mortara, Paolo; Fassino, Secondo

2013-09-30

110

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

PubMed

The aetiology of idiopathic scoliosis (IS) remains unknown, but there is growing support for the possibility of an underlying neurological disorder. Functional magnetic resonance imaging (fMRI) can characterize the abnormal activation of the sensorimotor brain network in movement disorders and could provide further insights into the neuropathogenesis of IS. Twenty subjects were included in the study; 10 adolescents with IS (mean age of 15.2, 8 girls and 2 boys) and 10 age-matched healthy controls. The average Cobb angle of the primary curve in the IS patients was 35° (range 27°-55°). All participants underwent a block-design fMRI experiment in a 1.5-Tesla MRI scanner to explore cortical activation following a simple motor task. Rest periods alternated with activation periods during which participants were required to open and close their hand at an internally paced rate of approximately 1 Hz. Data were analyzed with Statistical Parametric Mapping (SPM5) including age, sex and laterality as nuisance variables to minimise the presence of bias in the results. Compared to controls, IS patients showed significant increases in blood oxygenation level dependent (BOLD) activity in contralateral supplementary motor area when performing the motor task with either hand. No significant differences were observed when testing between groups in the functional activation in the primary motor cortex, premotor cortex and somatosensory cortex. Additionally, the IS group showed a greater interhemispheric asymmetry index than the control group (0.30 vs. 0.13, p < 0.001). This study demonstrates an abnormal pattern of brain activation in secondary motor areas during movement execution in patients with IS. These findings support the hypothesis that a sensorimotor integration disorder underlies the pathogenesis of IS. PMID:21499781

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

2011-07-01

111

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

112

Frontal cortical perfusion abnormalities related to gluten intake and associated autoimmune disease in adult coeliac disease: 99 m Tc ECD brain SPECT study  

Microsoft Academic Search

Objective. Since brain perfusion abnormalities have been described by single-photon emission computed tomography in some autoimmune diseases, the aim of the present study was to evaluate the incidence of perfusion abnormalities by brain single-photon emission computed tomography in a group of coeliac disease patients, and to investigate whether gluten intake and associated autoimmune diseases may be considered risk factors in

P Usai; A Serra; B Marini; S Mariotti; L Satta; M. F Boi; A Spanu; G Loi; M Piga

2004-01-01

113

Maternal autoantibodies are associated with abnormal brain enlargement in a subgroup of children with autism spectrum disorder  

PubMed Central

Autism spectrum disorder (ASD) is very heterogeneous and multiple subtypes and etiologies likely exist. The maternal immune system has been implicated in the pathogenesis of some forms of ASD. Previous studies have identified the presence of specific maternal IgG autoantibodies with reactivity to fetal brain proteins at 37 and 73KDa in up to 12% of mothers of children with ASD. The current study evaluates the presence of these autoantibodies in an independent cohort of mothers of 181 preschool-aged male children (131 ASD, 50 typically developing [TD] controls). We also investigated whether ASD children born to mothers with these autism-specific maternal IgG autoantibodies exhibit a distinct neural phenotype by evaluating total brain volume using structural magnetic resonance imaging (MRI). Of the 131 ASD children, 10 (7.6%) were born to mothers with the 37/73Kda IgG autoantibodies (ASD-IgG). The mothers of the remaining ASD children and all TD controls were negative for these paired autoantibodies. While both ASD groups exhibited abnormal brain enlargement that is commonly observed in this age range, the ASD-IgG group exhibited a more extreme 12.1% abnormal brain enlargement relative to the TD controls. In contrast, the remaining ASD children exhibited a smaller 4.4% abnormal brain enlargement relative to TD controls. Lobar and tissue type analyses revealed that the frontal lobe is selectively enlarged in the ASD-IgG group and that both gray and white matter are similarly affected. These results suggest that maternal autoantibodies associated with autism spectrum disorder may impact brain development leading to abnormal enlargement.

Nordahl, Christine Wu; Braunschweig, Daniel; Iosif, Ana-Maria; Lee, Aaron; Rogers, Sally; Ashwood, Paul; Amaral, David G.; Van de Water, Judy

2013-01-01

114

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

PubMed Central

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

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

2010-01-01

115

Are structural brain abnormalities associated with suicidal behavior in patients with psychotic disorders?  

PubMed

Suicide represents a major health problem world-wide. Nevertheless, the understanding of the neurobiological underpinnings of suicidal behavior remains far from complete. We compared suicide attempters to non-attempters, and high vs. low lethality attempters, to identify brain regions associated with suicidal behavior in patients with psychotic disorders. 489 individuals with schizophrenia, schizoaffective disorder, or psychotic bipolar disorder I and 262 healthy controls enrolled in the B-SNIP study were studied. Groups were compared by attempt history and the highest medical lethality of previous suicide attempts. 97 patients had a history of a high lethality attempt, 51 of a low lethality attempt and 341 had no attempt history. Gray matter volumes were obtained from 3T structural MRI scans using FreeSurfer. ANCOVAs were used to examine differences between groups, followed by Hochberg multiple comparison correction. Compared to non-attempters, attempters had significantly less gray matter volume in bilateral inferior temporal and superior temporal cortices, left superior parietal, thalamus and supramarginal regions, right insula, superior frontal and rostral middle frontal regions. Among attempters, a history of high lethality attempts was associated with significantly smaller volumes in the left lingual gyrus and right cuneus. Compared to non-attempters, low lethality attempters had significant decreases in the left supramarginal gyrus, thalamus and the right insula. Structural brain abnormalities may distinguish suicide attempters from non-attempters and high from low lethality attempters among individuals with psychotic disorders. Regions in which differences were observed are part of neural circuitries that mediate inhibition, impulsivity and emotion, visceral, visual and auditory perception. PMID:23866739

Giakoumatos, Christoforos I; Tandon, Neeraj; Shah, Jai; Mathew, Ian T; Brady, Roscoe O; Clementz, Brett A; Pearlson, Godfrey D; Thaker, Gunvant K; Tamminga, Carol A; Sweeney, John A; Keshavan, Matcheri S

2013-10-01

116

Abnormal Cortical Thickness and Brain-Behavior Correlation Patterns in Individuals with Heavy Prenatal Alcohol Exposure  

PubMed Central

Quantitative magnetic resonance imaging (MRI) studies in children with fetal alcohol spectrum disorders (FASDs) have shown regional patterns of dysmorphology, most prominent in parietal and posterior temporal cortices. Various methods of image analysis have been employed in these studies, but abnormalities in cortical thickness have not yet been mapped over the entire cortical surface in individuals with FASD. Further, relationships between cognitive dysfunction and cortical thickness measures have not yet been explored. We applied cortical pattern matching algorithms and techniques for measuring cortical thickness in millimeters to the structural brain MRI images of 21 subjects with heavy prenatal alcohol exposure (8–22 years, mean age 12.6 years), and 21 normally developing control subjects (8–25 years, mean age 13.5 years). Dissociable cognitive measures, of verbal recall and visuospatial functioning, were correlated with cortical thickness, and group by test score interactions were evaluated for predicting cortical thickness. Significant cortical thickness excesses of up to 1.2 mm were observed in the FASD subjects in large areas of bilateral temporal, bilateral inferior parietal, and right frontal regions. Significant group by test score interactions were found in right dorsal frontal regions for the verbal recall measure and in left occipital regions for the visuospatial measure. These results are consistent with earlier analyses from our own and other research groups, but for the first time, we show that cortical thickness is also increased in right lateral frontal regions in children with prenatal alcohol exposure. Further, the significant interactions show for the first time that brain-behavior relationships are altered as a function of heavy prenatal alcohol exposure.

Sowell, Elizabeth R.; Mattson, Sarah N.; Kan, Eric; Thompson, Paul M.; Riley, Edward P.; Toga, Arthur W.

2009-01-01

117

Structural brain abnormalities in borderline personality disorder: a voxel-based morphometry study.  

PubMed

Imaging studies using region-of-interest morphometry and positron emission tomography have contributed to our understanding of structural and functional abnormalities in borderline personality disorder (BPD); however, both methods have practical limitations to their usefulness for exploratory studies of brain-behavior relationships. We used voxel-based morphometry (VBM) in 34 subjects with BPD and 30 healthy control (HC) subjects to study effects of diagnosis, gender, childhood sexual abuse, depressed mood, impulsivity and aggression on group differences. VBM is a computer-based method for whole brain analysis that combines the advantages of a functional study with a structural method. The BPD subjects, diagnosed with the Diagnostic Interview for Borderline Patients and the International Personality Disorders Examination, were compared with 30 HC subjects, with age and gender covaried. Analyses were repeated separately by gender and, in women, by histories of childhood sexual abuse. Depressed mood, impulsivity, and aggression were covaried in separate analyses. Compared with HC, BPD subjects had significant bilateral reductions in gray matter concentrations in ventral cingulate gyrus and several regions of the medial temporal lobe, including the hippocampus, amygdala, parahippocampal gyrus, and uncus. BPD women (and abused BPD women), but not BPD men, had significant reductions in medial temporal lobe, including the amygdala. BPD men, but not BPD women, showed diminished gray matter concentrations in the anterior cingulate gyrus compared with findings in HC subjects. Covarying for depressed mood rendered group differences non-significant in the ventral cingulate but had little effect on differences in medial temporal cortex. Covarying for aggression (LHA) had relatively little effect on group differences, while covarying for impulsivity, as determined by the Barratt Impulsiveness Scale, rendered all previously noted voxel-level group differences non-significant. Diminished gray matter in the prefrontal cortex and the medial temporal cortex may mediate the dysregulation of impulse and affect in BPD. Group differences varied greatly by gender, levels of depression, and impulsivity. VBM is an efficient method for exploratory study of brain-behavior relationships. PMID:19019636

Soloff, Paul; Nutche, Jeffrey; Goradia, Dhruman; Diwadkar, Vaibhav

2008-12-30

118

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.

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

119

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

120

Loss of neuronal integrity: a cause of hypometabolism in patients with traumatic brain injury without MRI abnormality in the chronic stage  

Microsoft Academic Search

Purpose  Traumatic brain injury (TBI) causes brain dysfunction in many patients. However, some patients have severe brain dysfunction\\u000a but display no abnormalities on magnetic resonance imaging (MRI). There have been some reports of hypometabolism even in such\\u000a patients. The purpose of this study was to investigate the relationship between metabolic abnormality and loss of neuronal\\u000a integrity in TBI patients with some

Tohru Shiga; Katsunori Ikoma; Chietsugu Katoh; Hirotaka Isoyama; Tetsuaki Matsuyama; Yuji Kuge; Hiroyuki Kageyama; Tomoya Kohno; Satoshi Terae; Nagara Tamaki

2006-01-01

121

Functional brain abnormalities localized in 55 chronic tinnitus patients: fusion of SPECT coincidence imaging and MRI  

PubMed Central

Tinnitus is often defined as the perception of sounds or noise in the absence of any external auditory stimuli. The pathophysiology of subjective idiopathic tinnitus remains unclear. The aim of this study was to investigate the functional brain activities and possible involved cerebral areas in subjective idiopathic tinnitus patients by means of single photon emission computerized tomography (SPECT) coincidence imaging, which was fused with magnetic resonance imaging (MRI). In this cross-sectional study, 56 patients (1 subject excluded) with subjective tinnitus and 8 healthy controls were enrolled. After intravenous injection of 5?mCi F18-FDG (fluorodeoxyglucose), all subjects underwent a brain SPECT coincidence scan, which was then superimposed on their MRIs. In the eight regions of interest (middle temporal, inferotemporal, medial temporal, lateral temporal, temporoparietal, frontal, frontoparietal, and parietal areas), the more pronounced values were represented in medial temporal, inferotemporal, and temporoparietal areas, which showed more important proportion of associative auditory cortices in functional attributions of tinnitus than primary auditory cortex. Brain coincidence SPECT scan, when fused on MRI is a valuable technique in the assessment of patients with tinnitus and could show the significant role of different regions of central nervous system in functional attributions of tinnitus.

Farhadi, Mohammad; Mahmoudian, Saeid; Saddadi, Fariba; Karimian, Ali Reza; Mirzaee, Mohammad; Ahmadizadeh, Majid; Ghasemikian, Khosro; Gholami, Saeid; Ghoreyshi, Esmaeel; Beyty, Saeid; Shamshiri, Ahmadreza; Madani, Sedighe; Bakaev, Valery; Moradkhani, Seddighe; Raeisali, Gholamreza

2010-01-01

122

Functional brain abnormalities localized in 55 chronic tinnitus patients: fusion of SPECT coincidence imaging and MRI.  

PubMed

Tinnitus is often defined as the perception of sounds or noise in the absence of any external auditory stimuli. The pathophysiology of subjective idiopathic tinnitus remains unclear. The aim of this study was to investigate the functional brain activities and possible involved cerebral areas in subjective idiopathic tinnitus patients by means of single photon emission computerized tomography (SPECT) coincidence imaging, which was fused with magnetic resonance imaging (MRI). In this cross-sectional study, 56 patients (1 subject excluded) with subjective tinnitus and 8 healthy controls were enrolled. After intravenous injection of 5 mCi F18-FDG (fluorodeoxyglucose), all subjects underwent a brain SPECT coincidence scan, which was then superimposed on their MRIs. In the eight regions of interest (middle temporal, inferotemporal, medial temporal, lateral temporal, temporoparietal, frontal, frontoparietal, and parietal areas), the more pronounced values were represented in medial temporal, inferotemporal, and temporoparietal areas, which showed more important proportion of associative auditory cortices in functional attributions of tinnitus than primary auditory cortex. Brain coincidence SPECT scan, when fused on MRI is a valuable technique in the assessment of patients with tinnitus and could show the significant role of different regions of central nervous system in functional attributions of tinnitus. PMID:20068582

Farhadi, Mohammad; Mahmoudian, Saeid; Saddadi, Fariba; Karimian, Ali Reza; Mirzaee, Mohammad; Ahmadizadeh, Majid; Ghasemikian, Khosro; Gholami, Saeid; Ghoreyshi, Esmaeel; Beyty, Saeid; Shamshiri, Ahmadreza; Madani, Sedighe; Bakaev, Valery; Moradkhani, Seddighe; Raeisali, Gholamreza

2010-04-01

123

Neurovascular abnormalities in brain disorders: highlights with angiogenesis and magnetic resonance imaging studies  

PubMed Central

The coupling between neuronal activity and vascular responses is controlled by the neurovascular unit (NVU), which comprises multiple cell types. Many different types of dysfunction in these cells may impair the proper control of vascular responses by the NVU. Magnetic resonance imaging, which is the most powerful tool available to investigate neurovascular structures or functions, will be discussed in the present article in relation to its applications and discoveries. Because aberrant angiogenesis and vascular remodeling have been increasingly reported as being implicated in brain pathogenesis, this review article will refer to this hallmark event when suitable.

2013-01-01

124

High fat diet produces brain insulin resistance, synaptodendritic abnormalities and altered behavior in mice.  

PubMed

Insulin resistance and other features of the metabolic syndrome are increasingly recognized for their effects on cognitive health. To ascertain mechanisms by which this occurs, we fed mice a very high fat diet (60% kcal by fat) for 17days or a moderate high fat diet (HFD, 45% kcal by fat) for 8weeks and examined changes in brain insulin signaling responses, hippocampal synaptodendritic protein expression, and spatial working memory. Compared to normal control diet mice, cerebral cortex tissues of HFD mice were insulin-resistant as evidenced by failed activation of Akt, S6 and GSK3? with ex-vivo insulin stimulation. Importantly, we found that expression of brain IPMK, which is necessary for mTOR/Akt signaling, remained decreased in HFD mice upon activation of AMPK. HFD mouse hippocampus exhibited increased expression of serine-phosphorylated insulin receptor substrate 1 (IRS1-pS(616)), a marker of insulin resistance, as well as decreased expression of PSD-95, a scaffolding protein enriched in post-synaptic densities, and synaptopodin, an actin-associated protein enriched in spine apparatuses. Spatial working memory was impaired as assessed by decreased spontaneous alternation in a T-maze. These findings indicate that HFD is associated with telencephalic insulin resistance and deleterious effects on synaptic integrity and cognitive behaviors. PMID:24686304

Arnold, Steven E; Lucki, Irwin; Brookshire, Bethany R; Carlson, Gregory C; Browne, Caroline A; Kazi, Hala; Bang, Sookhee; Choi, Bo-Ran; Chen, Yong; McMullen, Mary F; Kim, Sangwon F

2014-07-01

125

Increases in brain white matter abnormalities and subcortical gray matter are linked to CD4 recovery in HIV infection.  

PubMed

MRI alterations in the cerebral white (WM) and gray matter (GM) are common in HIV infection, even during successful combination antiretroviral therapy (CART), and their pathophysiology and clinical significance are unclear. We evaluated the association of these alterations with recovery of CD4+ T cells. Seventy-five HIV-infected (HIV+) volunteers in the CNS HIV Anti-Retroviral Therapy Effects Research study underwent brain MRI at two visits. Multi-channel morphometry yielded volumes of total cerebral WM, abnormal WM, cortical and subcortical GM, and ventricular and sulcal CSF. Multivariable linear regressions were used to predict volumetric changes with change in current CD4 and detectable HIV RNA. On average, the cohort (79 % initially on CART) demonstrated loss of total cerebral WM alongside increases in abnormal WM and ventricular volumes. A greater extent of CD4 recovery was associated with increases in abnormal WM and subcortical GM volumes. Virologic suppression was associated with increased subcortical GM volume, independent of CD4 recovery. These findings suggest a possible link between brain alterations and immune recovery, distinct from the influence of virologic suppression. The association of increasing abnormal WM and subcortical GM volumes with CD4+ T cell recovery suggests that neuroinflammation may be one mechanism in CNS pathogenesis. PMID:23838849

Fennema-Notestine, Christine; Ellis, Ronald J; Archibald, Sarah L; Jernigan, Terry L; Letendre, Scott L; Notestine, Randy J; Taylor, Michael J; Theilmann, Rebecca J; Julaton, Michelle D; Croteau, David J; Wolfson, Tanya; Heaton, Robert K; Gamst, Anthony C; Franklin, Donald R; Clifford, David B; Collier, Ann C; Gelman, Benjamin B; Marra, Christina; McArthur, Justin C; McCutchan, J Allen; Morgello, Susan; Simpson, David M; Grant, Igor

2013-08-01

126

Abnormal grooming activity in Dab1(scm) (scrambler) mutant mice.  

PubMed

Dab1(scm) mutant mice, characterized by cell ectopias and degeneration in cerebellum, hippocampus, and neocortex, were compared to non-ataxic controls for different facets of grooming caused by brief water immersions, as well as some non-grooming behaviors. Dab1(scm) mutants were strongly affected in their quantitative functional parameters, exhibiting higher starting latencies before grooming relative to non-ataxic littermates of the A/A strain, fewer grooming bouts, and grooming components of shorter duration, with an unequal regional distribution targeting almost totally the rostral part (head washing and forelimb licking) of the animal. Only bouts of a single grooming element were preserved. The cephalocaudal order of grooming elements appeared less disorganized, mutant and control mice initiating the grooming with head washing and forelimb licking prior to licking posterior parts. However, mutants differed from controls in that all their bouts were incomplete but uninterrupted, although intergroup difference for percentage of the incorrect transitions was not significant. In contrast to grooming, Dab1(scm) mice ambulated for a longer time. During walking episodes, they exhibited more body scratching than controls, possibly to compensate for the lack of licking different body parts. In conjunction with studies with other ataxic mice, these results indicate that the cerebellar cortex affects grooming activity and is consequently involved in executing various components, but not in its sequential organization, which requires other brain regions such as cerebral cortices or basal ganglia. PMID:22561124

Strazielle, C; Lefevre, A; Jacquelin, C; Lalonde, R

2012-07-15

127

LIPID ABNORMALITIES IN SUCCINATE SEMIALDEHYDE DEHYDROGENASE (Aldh5a1?/?) DEFICIENT MOUSE BRAIN PROVIDE ADDITIONAL EVIDENCE FOR MYELIN ALTERATIONS  

PubMed Central

Earlier work from our laboratory provided evidence for myelin abnormalities (decreased quantities of proteins associated with myelin compaction, decreased sheath thickness) in cortex and hippocampus of Aldh5a1?/? mice, which have a complete ablation of the succinate semialdehyde dehydrogenase protein [1]. In the current report, we have extended these findings via comprehensive analysis of brain phospholipid fractions, including quantitation of fatty acids in individual phospholipid subclasses and estimation of hexose-ceramide in Aldh5a1?/? brain. In comparison to wild-type littermates (Aldh5a1+/+), we detected a 20% reduction in the ethanolamine glycerophospholipid content of Aldh5a1?/? mice, while other brain phospholipids (choline glycerophospholipid, phosphatidylserine and phosphatidylinositol) were within normal limits. Analysis of individual fatty acids in each of these fractions revealed consistent alterations in n-3 fatty acids, primarily increased 22:6n-3 levels (docosahexaenoic acid; DHA). In the phosphatidyl serine fraction there were marked increases in the proportions of polyunsaturated fatty acids with corresponding decreases of monounsaturated fatty acids. Interestingly, the levels of hexose-ceramide (glucosyl- and galactosylceramide, principal myelin cerebrosides) were decreased in Aldh5a1?/? brain tissue (one-tailed t test, p=0.0449). The current results suggest that lipid and myelin abnormalities in this animal may contribute to the pathophysiology.

Barcelo-Coblijn, G.; Murphy, E. J.; Mills, K.; Winchester, B.; Jakobs, C.; Snead, O.C.; Gibson, KM

2007-01-01

128

Kinin-forming activity in rat brain.  

PubMed

The present study shows that rat brain contains a kinin-forming activity which is distinguishable from plasma kallikrein. Kinin-forming activity was found in an acetone powder of frozen brain tissue (between 27 and 175.5 ng generated bradykinin/g fresh brain tissue/h). Analysis by high pressure liquid chromatography (HPLC) indicated that the kinin formed chromatographed like true bradykinin (BK). After subcellular fractionation using differential centrifugation of homogenized fresh brain tissue the kinin-forming activity was found mainly in a microsomal (P-3) fraction after preincubation with 2 ?M melittin. Further fractionation of P-3 fraction using discontinuous sucrose gradient centrifugation identified activity in both the 1 M sucrose layer (5.8 +/- 3.1 ng kinin/mg protein/h) and at the interface between the 0.8 and 0.3 sucrose layers (9.4 +/- 4 ng kinin/mg protein/h). Melittin pretreatment did not change these values. The distribution pattern of the kallikrein-like activity was different from that of cathepsin d-like acid protease. The two kinin-forming activities were equally sensitive to treatment with various trypsin inhibitors but were clearly distinguishable from plasma kallikrein: brain activity was inhibited completely by Trasylol but not by soybean trypsin inhibitor (SBTI) or ovomucoid while plasma kallikrein was completely inhibited by SBTI and partially by ovomucoid and Trasilol. Our results clearly distinguish between plasma kallikrein, brain cathepsin d-like acid protease activity and an apparent brain kinin-forming activity, but do not by themselves establish a central biosynthetic pathway for kinin generation. PMID:20492968

Shisheva, A C; Printz, M P; Herman, K; Ganten, D

1985-01-01

129

Circulating Omega-3 Polyunsaturated Fatty Acids and Subclinical Brain Abnormalities on MRI in Older Adults: The Cardiovascular Health Study  

PubMed Central

Background Consumption of tuna or other broiled or baked fish, but not fried fish, is associated with fewer subclinical brain abnormalities on magnetic resonance imaging (MRI). We investigated the association between plasma phospholipid omega?3 polyunsaturated fatty acids (PUFAs), objective biomarkers of exposure, and subclinical brain abnormalities on MRI. Methods and Results In the community?based Cardiovascular Health Study, 3660 participants aged ?65 underwent brain MRI in 1992–1994, and 2313 were rescanned 5 years later. MRIs were centrally read by neuroradiologists in a standardized, blinded manner. Participants with recognized transient ischemic attacks or stroke were excluded. Phospholipid PUFAs were measured in stored plasma collected in 1992–1993 and related to cross?sectional and longitudinal MRI findings. After multivariable adjustment, the odds ratio for having a prevalent subclinical infarct was 0.60 (95% CI, 0.44 to 0.82; P for trend=0.001) in the highest versus lowest long?chain omega?3 PUFA quartile. Higher long?chain omega?3 PUFA content was also associated with better white matter grade, but not with sulcal or ventricular grades, markers of brain atrophy, or with incident subclinical infarcts. The phospholipid intermediate?chain omega?3 PUFA alpha?linolenic acid was associated only with modestly better sulcal and ventricular grades. However, this finding was not supported in the analyses with alpha?linolenic acid intake. Conclusions Among older adults, higher phospholipid long?chain omega?3 PUFA content was associated with lower prevalence of subclinical infarcts and better white matter grade on MRI. Our results support the beneficial effects of fish consumption, the major source of long?chain omega?3 PUFAs, on brain health in later life. The role of plant?derived alpha?linolenic acid in brain health requires further investigation.

Virtanen, Jyrki K.; Siscovick, David S.; Lemaitre, Rozenn N.; Longstreth, William T.; Spiegelman, Donna; Rimm, Eric B.; King, Irena B.; Mozaffarian, Dariush

2013-01-01

130

Electrophysiological evidence of abnormal activation of the cerebral network of involuntary attention in alcoholism  

Microsoft Academic Search

Objective: Increased distractibility is a common impairment in alcoholism, but objective evidence has remained elusive. Here, a task designed to investigate with event-related brain potentials (ERPs) the neural mechanism underlying distraction was used to show abnormal involuntary orienting of attention in chronic alcoholism.Methods: Fifteen alcoholics and 17 matched healthy controls were instructed to ignore auditory stimuli while concentrating in the

Maria Dolores Polo; Carles Escera; Elena Yago; Kimmo Alho; Antoni Gual; Carles Grau

2003-01-01

131

Surface visualization of electromagnetic brain activity.  

PubMed

Advances in hardware and software have made possible the reconstruction of brain activity from non-invasive electrophysiological measurements over a large part of the brain. The appreciation of the information content in the data is enhanced when relevant anatomical detail is also available for visualization. Different neuroscientific questions give rise to different requirements for optimal superposition of structure and function. Most available software deal with scalar measures of activity, especially hemodynamic changes. In contrast, the electrophysiological observables are generated by electrical activity, which depends on the synchrony of neuronal assemblies and the geometry of the local cortical surface. We describe methods for segmentation and visualization of spatio-temporal brain activity, which allow the interplay of geometry and scalar as well as vector properties of the current density directly in the representations. The utility of these methods is demonstrated through displays of tomographic reconstructions of early sensory processing in the somatosensory and visual modality extracted from magnetoencephalography (MEG) data. The activation course characteristic to a specific area could be observed as current density or statistical maps independently and/or contrasted to the activity in other areas or the whole brain. MEG and functional magnetic resonance imaging (fMRI) activations were simultaneously visualized. Integrating and visualizing complementary functional data into a single environment helps evaluating analysis and understanding structure/function relationships in normal and diseased brain. PMID:12906943

Badea, Alexandra; Kostopoulos, George K; Ioannides, Andreas A

2003-08-15

132

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.

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

2013-01-01

133

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.

2009-01-01

134

Single-subject-based whole-brain MEG slow-wave imaging approach for detecting abnormality in patients with mild traumatic brain injury  

PubMed Central

Traumatic brain injury (TBI) is a leading cause of sustained impairment in military and civilian populations. However, mild TBI (mTBI) can be difficult to detect using conventional MRI or CT. Injured brain tissues in mTBI patients generate abnormal slow-waves (1–4 Hz) that can be measured and localized by resting-state magnetoencephalography (MEG). In this study, we develop a voxel-based whole-brain MEG slow-wave imaging approach for detecting abnormality in patients with mTBI on a single-subject basis. A normative database of resting-state MEG source magnitude images (1–4 Hz) from 79 healthy control subjects was established for all brain voxels. The high-resolution MEG source magnitude images were obtained by our recent Fast-VESTAL method. In 84 mTBI patients with persistent post-concussive symptoms (36 from blasts, and 48 from non-blast causes), our method detected abnormalities at the positive detection rates of 84.5%, 86.1%, and 83.3% for the combined (blast-induced plus with non-blast causes), blast, and non-blast mTBI groups, respectively. We found that prefrontal, posterior parietal, inferior temporal, hippocampus, and cerebella areas were particularly vulnerable to head trauma. The result also showed that MEG slow-wave generation in prefrontal areas positively correlated with personality change, trouble concentrating, affective lability, and depression symptoms. Discussion is provided regarding the neuronal mechanisms of MEG slow-wave generation due to deafferentation caused by axonal injury and/or blockages/limitations of cholinergic transmission in TBI. This study provides an effective way for using MEG slow-wave source imaging to localize affected areas and supports MEG as a tool for assisting the diagnosis of mTBI.

Huang, Ming-Xiong; Nichols, Sharon; Baker, Dewleen G.; Robb, Ashley; Angeles, Annemarie; Yurgil, Kate A.; Drake, Angela; Levy, Michael; Song, Tao; McLay, Robert; Theilmann, Rebecca J.; Diwakar, Mithun; Risbrough, Victoria B.; Ji, Zhengwei; Huang, Charles W.; Chang, Douglas G.; Harrington, Deborah L.; Muzzatti, Laura; Canive, Jose M.; Christopher Edgar, J.; Chen, Yu-Han; Lee, Roland R.

2014-01-01

135

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

PubMed

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

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

2012-11-01

136

Physical Activity, Brain Plasticity, and Alzheimer's Disease  

PubMed Central

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

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

2013-01-01

137

Novel molecular pathways elicited by mutant FGFR2 may account for brain abnormalities in Apert syndrome.  

PubMed

Apert syndrome (AS), the most severe form craniosynostosis, is characterized by premature fusion of coronal sutures. Approximately 70% of AS patients carry S252W gain-of-function mutation in FGFR2. Besides the cranial phenotype, brain dysmorphologies are present and are not seen in other FGFR2-asociated craniosynostosis, such as Crouzon syndrome (CS). Here, we hypothesized that S252W mutation leads not only to overstimulation of FGFR2 downstream pathway, but likewise induces novel pathological signaling. First, we profiled global gene expression of wild-type and S252W periosteal fibroblasts stimulated with FGF2 to activate FGFR2. The great majority (92%) of the differentially expressed genes (DEGs) were divergent between each group of cell populations and they were regulated by different transcription factors. We than compared gene expression profiles between AS and CS cell populations and did not observe correlations. Therefore, we show for the first time that S252W mutation in FGFR2 causes a unique cell response to FGF2 stimulation. Since our gene expression results suggested that novel signaling elicited by mutant FGFR2 might be associated with central nervous system (CNS) development and maintenance, we next investigated if DEGs found in AS cells were also altered in the CNS of an AS mouse model. Strikingly, we validated Strc (stereocilin) in newborn Fgfr2(S252W/+) mouse brain. Moreover, immunostaining experiments suggest a role for endothelial cells and cerebral vasculature in the establishment of characteristic CNS dysmorphologies in AS that has not been proposed by previous literature. Our approach thus led to the identification of new target genes directly or indirectly associated with FGFR2 which are contributing to the pathophysiology of AS. PMID:23593218

Yeh, Erika; Fanganiello, Roberto D; Sunaga, Daniele Y; Zhou, Xueyan; Holmes, Gregory; Rocha, Katia M; Alonso, Nivaldo; Matushita, Hamilton; Wang, Yingli; Jabs, Ethylin W; Passos-Bueno, Maria Rita

2013-01-01

138

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.

Senapati, Gunjan; Levine, Deborah

2013-01-01

139

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.

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

140

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

141

Functional brain abnormalities during finger-tapping in HIV-infected older adults: a magnetoencephalography study.  

PubMed

Despite the availability of combination antiretroviral therapy, at least mild cognitive dysfunction is commonly observed in HIV-infected patients, with an estimated prevalence of 35-70 %. Neuropsychological studies of these HIV-associated neurocognitive disorders (HAND) have documented aberrations across a broad range of functional domains, although the basic pathophysiology remains unresolved. Some of the most common findings have been deficits in fine motor control and reduced psychomotor speed, but to date no neuroimaging studies have evaluated basic motor control in HAND. In this study, we used magnetoencephalography (MEG) to evaluate the neurophysiological processes that underlie motor planning in older HIV-infected adults and a matched, uninfected control group. MEG is a noninvasive and direct measure of neural activity with good spatiotemporal precision. During the MEG recording, participants fixated on a central crosshair and performed a finger-tapping task with the dominant hand. All MEG data was corrected for head movements, preprocessed, and imaged in the time-frequency domain using beamforming methodology. All analyses focused on the pre-movement beta desynchronization, which is known to be an index of movement planning. Our results demonstrated that HIV-1-infected patients have deficient beta desynchronization relative to controls within the left/right precentral gyri, and the supplementary motor area. In contrast, HIV-infected persons showed abnormally strong beta responses compared to controls in the right dorsolateral prefrontal cortex and medial prefrontal areas. In addition, the amplitude of beta activity in the primary and supplementary motor areas correlated with scores on the Grooved Pegboard test in HIV-infected adults. These results demonstrate that primary motor and sensory regions may be particularly vulnerable to HIV-associated damage, and that prefrontal cortices may serve a compensatory role in maintaining motor performance levels in infected patients. PMID:23749418

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

2013-09-01

142

The hyperactive syndrome: Metanalysis of genetic alterations, pharmacological treatments and brain lesions which increase locomotor activity  

Microsoft Academic Search

The large number of transgenic mice realized thus far with different purposes allows addressing new questions, such as which animals, over the entire set of transgenic animals, show a specific behavioural abnormality. In the present study, we have used a metanalytical approach to organize a database of genetic modifications, brain lesions and pharmacological interventions that increase locomotor activity in animal

Davide Viggiano

2008-01-01

143

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

144

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

145

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

146

Paradigms for recording cognitive brain electrical activity.  

PubMed

Human event-related potentials reflect cognitive processing, and are normally elicited by external events, such as acoustic sounds or visual stimuli. As such they provide an opportunity to study normal and abnormal brain function noninvasively, at sub-second resolution. Advances in multimedia technology permit specialists in informatics and neuropsychology to co-operate in the design and implementation of paradigms, which influence ERP components. The paper illustrates the progression from standard paradigms such as the auditory oddball, which can be used to study memory update through to contingent negative variation and three condition, visual paradigms which can be used to study cognitive and emotional responses. Data from a study investigating the comparative processing of target pictures and words illustrate how external stimuli influence the later cognitive potentials. PMID:11501630

McCullagh, P J; McAllister, H G; Howard, R; Neo, L H

2001-07-01

147

Abnormal structure of frontostriatal brain systems is associated with aspects of impulsivity and compulsivity in cocaine dependence  

PubMed Central

A growing body of preclinical evidence indicates that addiction to cocaine is associated with neuroadaptive changes in frontostriatal brain systems. Human studies in cocaine-dependent individuals have shown alterations in brain structure, but it is less clear how these changes may be related to the clinical phenotype of cocaine dependence characterized by impulsive behaviours and compulsive drug-taking. Here we compared self-report, behavioural and structural magnetic resonance imaging data on a relatively large sample of cocaine-dependent individuals (n?=?60) with data on healthy volunteers (n?=?60); and we investigated the relationships between grey matter volume variation, duration of cocaine use, and measures of impulsivity and compulsivity in the cocaine-dependent group. Cocaine dependence was associated with an extensive system of abnormally decreased grey matter volume in orbitofrontal, cingulate, insular, temporoparietal and cerebellar cortex, and with a more localized increase in grey matter volume in the basal ganglia. Greater duration of cocaine dependence was correlated with greater grey matter volume reduction in orbitofrontal, cingulate and insular cortex. Greater impairment of attentional control was associated with reduced volume in insular cortex and increased volume of caudate nucleus. Greater compulsivity of drug use was associated with reduced volume in orbitofrontal cortex. Cocaine-dependent individuals had abnormal structure of corticostriatal systems, and variability in the extent of anatomical changes in orbitofrontal, insular and striatal structures was related to individual differences in duration of dependence, inattention and compulsivity of cocaine consumption.

Barnes, Anna; Simon Jones, P.; Morein-Zamir, Sharon; Robbins, Trevor W.; Bullmore, Edward T.

2011-01-01

148

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

149

Divergent structural brain abnormalities between different genetic subtypes of children with Prader-Willi syndrome  

PubMed Central

Background Prader–Willi syndrome (PWS) is a complex neurogenetic disorder with symptoms that indicate not only hypothalamic, but also a global, central nervous system (CNS) dysfunction. However, little is known about developmental differences in brain structure in children with PWS. Thus, our aim was to investigate global brain morphology in children with PWS, including the comparison between different genetic subtypes of PWS. In addition, we performed exploratory cortical and subcortical focal analyses. Methods High resolution structural magnetic resonance images were acquired in 20 children with genetically confirmed PWS (11 children carrying a deletion (DEL), 9 children with maternal uniparental disomy (mUPD)), and compared with 11 age- and gender-matched typically developing siblings as controls. Brain morphology measures were obtained using the FreeSurfer software suite. Results Both children with DEL and mUPD showed smaller brainstem volume, and a trend towards smaller cortical surface area and white matter volume. Children with mUPD had enlarged lateral ventricles and larger cortical cerebrospinal fluid (CSF) volume. Further, a trend towards increased cortical thickness was found in children with mUPD. Children with DEL had a smaller cerebellum, and smaller cortical and subcortical grey matter volumes. Focal analyses revealed smaller white matter volumes in left superior and bilateral inferior frontal gyri, right cingulate cortex, and bilateral precuneus areas associated with the default mode network (DMN) in children with mUPD. Conclusions Children with PWS show signs of impaired brain growth. Those with mUPD show signs of early brain atrophy. In contrast, children with DEL show signs of fundamentally arrested, although not deviant brain development and presented few signs of cortical atrophy. Our results of global brain measurements suggest divergent neurodevelopmental patterns in children with DEL and mUPD.

2013-01-01

150

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

151

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

152

MRI analysis of an inherited speech and language disorder: structural brain abnormalities  

Microsoft Academic Search

Summary Analyses of brain structure in genetic speech and lan- guage disorders provide an opportunity to identify neu- robiological phenotypes and further elucidate the neural bases of language and its development. Here we report such investigations in a large family, known as the KE family, half the members of which are affected by a severe disorder of speech and language,

K. E. Watkins; F. Vargha-Khadem; J. Ashburner; R. E. Passingham; A. Connelly; K. J. Friston; R. S. J. Frackowiak; M. Mishkin; D. G. Gadian

2002-01-01

153

Co-Localisation of Abnormal Brain Structure and Function in Specific Language Impairment  

ERIC Educational Resources Information Center

We assessed the relationship between brain structure and function in 10 individuals with specific language impairment (SLI), compared to six unaffected siblings, and 16 unrelated control participants with typical language. Voxel-based morphometry indicated that grey matter in the SLI group, relative to controls, was increased in the left inferior…

Badcock, Nicholas A.; Bishop, Dorothy V. M.; Hardiman, Mervyn J.; Barry, Johanna G.; Watkins, Kate E.

2012-01-01

154

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

155

Abnormal Functional MRI BOLD Contrast in the Vegetative State after Severe Traumatic Brain Injury  

ERIC Educational Resources Information Center

For the rehabilitation process, the treatment of patients surviving brain injury in a vegetative state is still a serious challenge. The aim of this study was to investigate patients exhibiting severely disturbed consciousness using functional magnetic resonance imaging. Five cases of posttraumatic vegetative state and one with minimal…

Heelmann, Volker

2010-01-01

156

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

PubMed

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

LaViolette, Peter S; Daun, Mitchell K; Paulson, Eric S; Schmainda, Kathleen M

2014-02-01

157

Absence of PTHrP Nuclear Localization and Carboxyl Terminus Sequences Leads to Abnormal Brain Development and Function  

PubMed Central

We assessed whether the nuclear localization sequences (NLS) and C terminus of parathyroid hormone-related protein (PTHrP) play critical roles in brain development and function. We used histology, immunohistochemistry, histomorphometry, Western blots and electrophysiological recordings to compare the proliferation and differentiation of neural stem cells, neuronal hippocampal synaptic transmission, and brain phenotypes including shape and structures, in Pthrp knock-in mice, which express PTHrP (1–84), a truncated form of the protein that is missing the NLS and the C-terminal region of the protein, and their wild-type littermates. Results showed that Pthrp knock-in mice display abnormal brain shape and structures; decreased neural cell proliferative capacity and increased apoptosis associated with up-regulation of cyclin dependent kinase inhibitors p16, p21, p27 and p53 and down-regulation of the Bmi-1 oncogene; delayed neural cell differentiation; and impaired hippocampal synaptic transmission and plasticity. These findings provide in vivo experimental evidence that the NLS and C-terminus of PTHrP are essential not only for the regulation of neural cell proliferation and differentiation, but also for the maintenance of normal neuronal synaptic transmission and plasticity.

Gu, Zhen; Liu, Yahong; Zhang, Yongjie; Jin, Shulei; Chen, Qi; Goltzman, David; Karaplis, Andrew; Miao, Dengshun

2012-01-01

158

Abnormal copper metabolism and deficient lysyl oxidase activity in a heritable connective tissue disorder.  

PubMed

Biochemical abnormalities were studied in two brothers with bladder divericulas, inguinal hernias, slight skin laxity, and hyperelasticity and skeletal abnormalities including occipital exostoses. Lysyl oxidase activity was low in the medium of cultured skin fibroblasts, this abnormality being accompanied by reduced conversion of the newly synthesized collagen into the soluble form. Copper concentrations were markedly elevated in the cultured skin fibroblasts, but decreased in the serum and hair. Serum cerulophasmin levels were also low. The reduced lysyl oxidase activity is suggested to be responsible for ther clinical manifestations, but the deficiency in this copper-dependent enzyme may be secondary to the abnormalities in the metabolism of the cation. Nevertheless, a mutation directly affecting both lysyl oxidase and an intracellular copper transport protein cannot be excluded. The disease is tentatively classified as one subtype of the Ehlers-Danlos syndrome. PMID:6120954

Kuivaniemi, H; Peltonen, L; Palotie, A; Kaitila, I; Kivirikko, K I

1982-03-01

159

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.

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

1988-01-01

160

Abnormal Cortical Development after Premature Birth Shown by Altered Allometric Scaling of Brain Growth  

PubMed Central

Background We postulated that during ontogenesis cortical surface area and cerebral volume are related by a scaling law whose exponent gives a quantitative measure of cortical development. We used this approach to investigate the hypothesis that premature termination of the intrauterine environment by preterm birth reduces cortical development in a dose-dependent manner, providing a neural substrate for functional impairment. Methods and Findings We analyzed 274 magnetic resonance images that recorded brain growth from 23 to 48 wk of gestation in 113 extremely preterm infants born at 22 to 29 wk of gestation, 63 of whom underwent neurodevelopmental assessment at a median age of 2 y. Cortical surface area was related to cerebral volume by a scaling law with an exponent of 1.29 (95% confidence interval, 1.25–1.33), which was proportional to later neurodevelopmental impairment. Increasing prematurity and male gender were associated with a lower scaling exponent (p < 0.0001) independent of intrauterine or postnatal somatic growth. Conclusions Human brain growth obeys an allometric scaling relation that is disrupted by preterm birth in a dose-dependent, sexually dimorphic fashion that directly parallels the incidence of neurodevelopmental impairments in preterm infants. This result focuses attention on brain growth and cortical development during the weeks following preterm delivery as a neural substrate for neurodevelopmental impairment after premature delivery.

Kapellou, Olga; Counsell, Serena J; Kennea, Nigel; Dyet, Leigh; Saeed, Nadeem; Stark, Jaroslav; Maalouf, Elia; Duggan, Philip; Ajayi-Obe, Morenike; Hajnal, Jo; Allsop, Joanna M; Boardman, James; Rutherford, Mary A; Cowan, Frances; Edwards, A. David

2006-01-01

161

Brain gene expression differences are associated with abnormal tail biting behavior in pigs.  

PubMed

Knowledge about gene expression in animals involved in abnormal behaviors can contribute to the understanding of underlying biological mechanisms. This study aimed to explore the motivational background to tail biting, an abnormal injurious behavior and severe welfare problem in pig production. Affymetrix microarrays were used to investigate gene expression differences in the hypothalamus and prefrontal cortex of pigs performing tail biting, pigs receiving bites to the tail and neutral pigs who were not involved in the behavior. In the hypothalamus, 32 transcripts were differentially expressed (P < 0.05) when tail biters were compared with neutral pigs, 130 when comparing receiver pigs with neutrals, and two when tail biters were compared with receivers. In the prefrontal cortex, seven transcripts were differently expressed in tail biters when compared with neutrals, seven in receivers vs. neutrals and none in the tail biters vs. receivers. In total, 19 genes showed a different expression pattern in neutral pigs when compared with both performers and receivers. This implies that the functions of these may provide knowledge about why the neutral pigs are not involved in tail biting behavior as performers or receivers. Among these 19 transcripts were genes associated with production traits in pigs (PDK4), sociality in humans and mice (GTF2I) and novelty seeking in humans (EGF). These are in line with hypotheses linking tail biting with reduced back fat thickness and explorative behavior. PMID:23146156

Brunberg, E; Jensen, P; Isaksson, A; Keeling, L J

2013-03-01

162

Activation of Stat3 in Human Melanoma Promotes Brain Metastasis  

Microsoft Academic Search

Brain metastasis is a major cause of morbidity and mortality in patients with melanoma. The molecular changes that lead to brain metastasis remain poorly understood. In this study, we developed a model to study human melanoma brain metastasis and found that Stat3 activity was increased in human brain metastatic melanoma cells when compared with that in cutaneous melanoma cells. The

Tong-xin Xie; Feng-Ju Huang; Kenneth D. Aldape; Mingguang Liu; Jeffrey E. Gershenwald; Keping Xie; Raymond Sawaya; Suyun Huang

163

Steroid abnormalities and the developing brain: Declarative memory for emotionally arousing and neutral material in children with congenital adrenal hyperplasia  

PubMed Central

Summary Steroid hormones modulate memory in animals and human adults. Little is known on the developmental effect of these hormones on the neural networks underlying memory. Using Congenital Adrenal Hyperplasia (CAH) as a naturalistic model of early steroid abnormalities, this study examines the consequences of CAH on memory and its neural correlates for emotionally arousing and neutral material in children. Seventeen patients with CAH and 17 age- and sex-matched healthy children (ages 12 to 14 years) completed the study. Subjects were presented positive, negative and neutral pictures. Memory recall occurred about 30 minutes after viewing the pictures. Children with CAH showed memory deficits for negative pictures compared to healthy children (p < 0.01). There were no group differences on memory performance for either positive or neutral pictures (p’s >0.1). In patients, 24h urinary-free cortisol levels (reflecting glucocorticoid replacement therapy) and testosterone levels were not associated with memory performance. These findings suggest that early steroid imbalances affect memory for negative material in children with CAH. Such memory impairments may result from abnormal brain organization and function following hormonal dysfunction during critical periods of development.

Maheu, Francoise S.; Merke, Deborah P.; Schroth, Elizabeth A.; Keil, Margaret F.; Hardin, Julie; Poeth, Kaitlin; Pine, Daniel S.; Ernst, Monique

2008-01-01

164

Brain volume abnormalities and neurocognitive deficits in diabetes mellitus: Points of pathophysiological commonality with mood disorders?  

Microsoft Academic Search

Background  It is hypothesized that diabetes mellitus (DM) and mood disorders share points of pathophysiological commonality in the central\\u000a nervous system.\\u000a \\u000a \\u000a \\u000a \\u000a Methods  A PubMed search of all English-language articles published between 1966 and March 2009 was performed with the following search\\u000a terms: depression, mood disorders, hippocampus, amygdala, central nervous system, brain, neuroimaging, volumetric, morphometric,\\u000a and neurocognitive deficits, cross-referenced with DM. Articles selected

Roger S. McIntyre; Heather A. Kenna; Ha T. Nguyen; Candy W. Y. Law; Farah Sultan; Hanna O. Woldeyohannes; Mohammad T. Alsuwaidan; Joanna K. Soczynska; Amanda K. Adams; Jenny S. H. Cheng; Maria Lourenco; Sidney H. Kennedy; Natalie L. Rasgon

2010-01-01

165

Smoking Intensity and Lipoprotein Abnormalities in Active Smokers  

PubMed Central

Background Smoking is associated with decreased high-density lipoprotein cholesterol (HDL-C) and elevated triglycerides. Objective To evaluate the effects of five markers of smoking intensity on lipoprotein concentrations and particle sizes in a large, modern cohort of current smokers. Methods Fasting nuclear magnetic resonance spectroscopy lipoprotein profiles were obtained in a large cohort of current smokers enrolled in a smoking cessation trial. Multivariate linear regression models were constructed to determine predictors of lipoprotein fractions. Models included age, sex, race, waist circumference, level of physical activity and alcohol consumption. Smoking intensity parameters included: current cigarettes smoked/day, pack-years, the Fagerström Test of Nicotine Dependence (FTND) score, and carbon monoxide (CO) levels. Results The 1,504 subjects (58% women, 84% white) had a mean (standard deviation) age of 45 (11.0) years. They smoked 21.4 (8.9) cigarettes/day (29.4 [20.4] pack-years). HDL-C (42.0 [13.5] mg/dL) and total HDL particles (30.3 [5.9] ?mol/L) were low. Cigarettes smoked/day independently predicted higher total cholesterol (p=0.009), low-density lipoprotein cholesterol (p=0.023), and triglycerides (p=0.002). CO levels predicted lower HDL-C (p=0.027) and total HDL particles (p=0.009). However, the incremental R2 for each marker of smoking intensity on each lipoprotein was small. Relationships between the FTND score and lipoproteins were weak and inconsistent. Participants in the lowest quintiles of current smoking, pack-years, and CO had more favorable lipoproteins (all p<0.04). Conclusions Among current smokers, increased smoking burden is associated with small increases in total cholesterol, LDL-C, and triglycerides. Increased recent smoke exposure is associated with small decreases in HDL-C and HDL particles.

Gossett, Linda K.; Johnson, Heather M.; Piper, Megan E.; Fiore, Michael C.; Baker, Timothy B.; Stein, James H.

2009-01-01

166

Brain MR Spectroscopic Abnormalities in "MRI-negative" Tuberous Sclerosis Complex Patients  

PubMed Central

Since approximately 5–10% of the ~50,000 Tuberous Sclerosis Complex (TSC) patients in the US are “MRI-negative,” our goal was to test the hypothesis that they nevertheless exhibit metabolic abnormalities. To test this, we used proton-MR spectroscopy to obtain and compare gray and white matter (GM, WM) levels of the neuronal marker N-acetylaspartate (NAA); the glial marker, myo-inositol (mI) and its associated creatine (Cr) and choline (Cho), between two “MRI-negative” female TSC patients (5- and 43-year-olds) and their matched controls. The NAA, Cr, Cho and mI concentrations in the pediatric control: 9.8, 6.3, 1.4 and 5.7 millimolar, were similar to the patient’s; whereas the adult patient revealed a 17% WM NAA decrease and 16% WM Cho increase from their published means for healthy adults - both outside their respective 90% prediction intervals. These findings suggest that longer disease duration and/or TSC2 gene mutation may cause axonal dysfunction and demyelination.

Wu, William E.; Kirov, Ivan I.; Tal, Assaf; Babb, James S.; Milla, Sarah; Oved, Joseph; Weiner, Howard L.; Devinsky, Orrin; Gonen, Oded

2013-01-01

167

Neurochemical Evidence that Pristanic Acid Impairs Energy Production and Inhibits Synaptic Na + , K + ATPase Activity in Brain of Young Rats  

Microsoft Academic Search

Pristanic acid (Prist) accumulates in some peroxisomal disorders characterized by neurologic dysfunction and brain abnormalities.\\u000a The present work investigated the in vitro effects of Prist on important parameters of energy metabolism in brain cortex of\\u000a young rats. CO2 production from labeled acetate and the activities of the respiratory chain complexes I–IV, creatine kinase and synaptic\\u000a Na+, K+-ATPase were measured. Prist

Estela Natacha Brandt Busanello; Carolina Maso Viegas; Anelise Miotti Tonin; Mateus Grings; Alana Pimentel Moura; Anderson Büker de Oliveira; Paula Eichler; Moacir Wajner

2011-01-01

168

Leukocyte activation in the decidua of chromosomally normal and abnormal fetuses from women with recurrent abortion  

Microsoft Academic Search

As part of our continuing programme to investigate immunological causes of unexplained recurrent pregnancy losses, we studied subpopulations of white blood cells and their activation status in decidua of women with a history of recurrent spontaneous abortion (RSA). We differentiated specifically between normal karyotyped male fetuses and abnormal karyotyped fetuses with trisomy 16 because trisomy 16 is not compatible with

Katharina C. Quack; Neratzoula Vassiliadou; Jeffrey Pudney; Deborah J. Anderson; Joseph A. Hill

169

"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.

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

2010-01-01

170

Anger style, psychopathology, and regional brain activity.  

PubMed

Depression and anxiety often involve high levels of trait anger and disturbances in anger expression. Reported anger experience and outward anger expression have recently been associated with left-biased asymmetry of frontal cortical activity, assumed to reflect approach motivation. However, different styles of anger expression could presumably involve different brain mechanisms and/or interact with psychopathology to produce various patterns of brain asymmetry. The present study explored these issues by comparing resting regional electroencephalographic activity in participants high in trait anger who differed in anger expression style (high anger-in, high anger-out, both) and participants low in trait anger, with depression and anxiety systematically assessed. Trait anger, not anger-in or anger-out, predicted left-biased asymmetry at medial frontal EEG sites. The anger-in group reported higher levels of anxious apprehension than did the anger-out group. Furthermore, anxious apprehension moderated the relationship between trait anger, anger-in, and asymmetry in favor of the left hemisphere. Results suggest that motivational direction is not always the driving force behind the relationship of anger and left frontal asymmetry. Findings also support a distinction between anxious apprehension and anxious arousal. PMID:18837620

Stewart, Jennifer L; Levin-Silton, Rebecca; Sass, Sarah M; Heller, Wendy; Miller, Gregory A

2008-10-01

171

Brain Activity with Reading Sentences and Emoticons  

NASA Astrophysics Data System (ADS)

In this paper, we describe a person's brain activity when he/she sees an emoticon at the end of a sentence. An emoticon consists of some characters that resemble the human face and expresses a sender's emotion. With the help of a computer network, we use e-mail, messenger, avatars and so on, in order to convey what we wish to, to a receiver. Moreover, we send an emotional expression by using an emoticon at the end of a sentence. In this research, we investigate the effect of an emoticon as nonverbal information, using an fMRI study. The experimental results show that the right and left inferior frontal gyrus were activated and we detect a sentence with an emoticon as the verbal and nonverval information.

Yuasa, Masahide; Saito, Keiichi; Mukawa, Naoki

172

Constitutively Activated NLRP3 Inflammasome Causes Inflammation and Abnormal Skeletal Development in Mice  

PubMed Central

The NLRP3 inflammasome complex is responsible for maturation of the pro-inflammatory cytokine, IL-1?. Mutations in NLRP3 are responsible for the cryopyrinopathies, a spectrum of conditions including neonatal-onset multisystem inflammatory disease (NOMID). While excessive production of IL-1? and systemic inflammation are common to all cryopyrinopathy disorders, skeletal abnormalities, prominently in the knees, and low bone mass are unique features of patients with NOMID. To gain insights into the mechanisms underlying skeletal abnormalities in NOMID, we generated knock-in mice globally expressing the D301N NLRP3 mutation (ortholog of D303N in human NLRP3). NOMID mice exhibit neutrophilia in blood and many tissues, including knee joints, and high levels of serum inflammatory mediators. They also exhibit growth retardation and severe postnatal osteopenia stemming at least in part from abnormally accelerated bone resorption, attended by increased osteoclastogenesis. Histologic analysis of knee joints revealed abnormal growth plates, with loss of chondrocytes and growth arrest in the central region of the epiphyses. Most strikingly, a tissue “spike" was observed in the mid-region of the growth plate in the long bones of all NOMID mice that may be the precursor to more severe deformations analogous to those observed in NOMID patients. These findings provide direct evidence linking a NOMID-associated NLRP3-activating mutation to abnormalities of postnatal skeletal growth and bone remodeling.

McGeough, Matthew D.; Pena, Carla; Chen, Debbie; Grimston, Susan K.; Hickman-Brecks, Cynthia L.; Ravindran, Soumya; McAlinden, Audrey; Novack, Deborah V.; Kastner, Daniel L.; Civitelli, Roberto; Hoffman, Hal M.; Mbalaviele, Gabriel

2012-01-01

173

Effects of a Carbohydrate Supplement upon Resting Brain Activity  

Microsoft Academic Search

Glucose is a major energy source for the brain, and along with several monosaccharide derivatives as components of brain gangliosides, they play important roles in neurologic function. However, there is little information available on the role of glucose and other monosaccharides on resting brain activity. This study was designed to evaluate the effects of a single dose of a carbohydrate

CHENGHUA WANG; JOANNE S. SZABO; ROSCOE A. DYKMAN

2004-01-01

174

Solar activity cycle and the incidence of foetal chromosome abnormalities detected at prenatal diagnosis  

NASA Astrophysics Data System (ADS)

We studied 2001 foetuses during the period of minimal solar activity of solar cycle 21 and 2265 foetuses during the period of maximal solar activity of solar cycle 22, in all women aged 37 years and over who underwent free prenatal diagnosis in four hospitals in the greater Tel Aviv area. There were no significant differences in the total incidence of chromosomal abnormalities or of trisomy between the two periods (2.15% and 1.8% versus 2.34% and 2.12%, respectively). However, the trend of excessive incidence of chromosomal abnormalities in the period of maximal solar activity suggests that a prospective study in a large population would be required to rule out any possible effect of extreme solar activity.

Halpern, Gabrielle J.; Stoupel, Eliahu G.; Barkai, Gad; Chaki, Rina; Legum, Cyril; Fejgin, Moshe D.; Shohat, Mordechai

1995-06-01

175

Brain activation during anticipation of interoceptive threat.  

PubMed

The current study investigated the neural networks activated during the anticipation of potentially threatening body symptoms evoked by a guided hyperventilation task in a group of participants reporting either high or low fear of unexplained somatic sensations. 15 subjects reporting high and 14 subjects reporting low fear of somatic symptoms first learned that one of two cues predicted the occurrence of a hyperventilation task reliably producing body symptoms in all participants that were rated as more intense and unpleasant in the high fear group. During anticipation of unpleasant symptoms, high fear participants reported more intense body symptoms and showed potentiation of the startle reflex. After this learning session, participants were taken into the fMRI where the same cues either predicted the occurrence of hyperventilation or normoventilation, although the task was never performed in the scanner. During anticipation of hyperventilation all participants showed an increased activation of anterior insula/orbitofrontal cortex and rostral parts of the dorsal anterior cingulate cortex/dorsomedial prefrontal cortex (dACC/dmPFC). Brain activation of high compared to low fear participants differed in two ways. First, high fear participants showed an overall stronger activation of this network during threat and safe conditions indexing stronger anxious apprehension during the entire context. Second, while low fear participants no longer responded with stronger activation to the threat cue after experiencing that the hyperventilation challenge did not follow this cue, high fear participants continued to show stronger activation of the network to this cue. Activation of the rostral dACC/dmPFC was significantly correlated with reported fear of somatic symptoms. These data demonstrate that anticipation of interoceptive threat activates the same network that has been found to be active during anticipation of exteroceptive threat cues. Thus, the current paradigm might provide an innovative method to study anxious apprehension and treatment effects in patients with panic disorder. PMID:22440646

Holtz, Katharina; Pané-Farré, Christiane A; Wendt, Julia; Lotze, Martin; Hamm, Alfons O

2012-07-16

176

The neurological significance of abnormal natural killer cell activity in chronic toxigenic mold exposures.  

PubMed

Toxigenic mold activities produce metabolites that are either broad-spectrum antibiotics or mycotoxins that are cytotoxic. Indoor environmental exposure to these toxigenic molds leads to adverse health conditions with the main outcome measure of frequent neuroimmunologic and behavioral consequences. One of the immune system disorders found in patients presenting with toxigenic mold exposure is an abnormal natural killer cell activity. This paper presents an overview of the neurological significance of abnormal natural killer cell (NKC) activity in chronic toxigenic mold exposure. A comprehensive review of the literature was carried out to evaluate and assess the conditions under which the immune system could be dysfunctionally interfered with leading to abnormal NKC activity and the involvement of mycotoxins in these processes. The functions, mechanism, the factors that influence NKC activities, and the roles of mycotoxins in NKCs were cited wherever necessary. The major presentations are headache, general debilitating pains, nose bleeding, fevers with body temperatures up to 40 degrees C (104 degrees F), cough, memory loss, depression, mood swings, sleep disturbances, anxiety, chronic fatigue, vertigo/dizziness, and in some cases, seizures. Although sleep is commonly considered a restorative process that is important for the proper functioning of the immune system, it could be disturbed by mycotoxins. Most likely, mycotoxins exert some rigorous effects on the circadian rhythmic processes resulting in sleep deprivation to which an acute and transient increase in NKC activity is observed. Depression, psychological stress, tissue injuries, malignancies, carcinogenesis, chronic fatigue syndrome, and experimental allergic encephalomyelitis could be induced at very low physiological concentrations by mycotoxin-induced NKC activity. In the light of this review, it is concluded that chronic exposures to toxigenic mold could lead to abnormal NKC activity with a wide range of neurological consequences, some of which were headache, general debilitating pains, fever, cough, memory loss, depression, mood swings, sleep disturbances, anxiety, chronic fatigue, and seizures. PMID:14625399

Anyanwu, Ebere; Campbell, Andrew W; Jones, Joseph; Ehiri, John E; Akpan, Akpan I

2003-11-13

177

Characterization of activated sludge abnormalities by image analysis and chemometric techniques  

Microsoft Academic Search

This work focuses on the use of chemometric techniques for identifying activated sludge process abnormalities. Chemometric methods combined with image analysis can improve activated sludge systems monitoring and minimize the need of analytical measurements. For that purpose data was collected from aggregated and filamentous biomass, biomass composition on Gram-positive\\/Gram-negative bacteria and viable\\/damaged bacteria, and operational parameters. Principal component analysis (PCA)

D. P. Mesquita; A. L. Amaral; E. C. Ferreira

2011-01-01

178

Abnormal neuronal patterning occurs during early postnatal brain development of Scn1b-null mice and precedes hyperexcitability.  

PubMed

Voltage-gated Na(+) channel (VGSC) ?1 subunits, encoded by SCN1B, are multifunctional channel modulators and cell adhesion molecules (CAMs). Mutations in SCN1B are associated with the genetic epilepsy with febrile seizures plus (GEFS+) spectrum disorders in humans, and Scn1b-null mice display severe spontaneous seizures and ataxia from postnatal day (P)10. The goal of this study was to determine changes in neuronal pathfinding during early postnatal brain development of Scn1b-null mice to test the hypothesis that these CAM-mediated roles of Scn1b may contribute to the development of hyperexcitability. c-Fos, a protein induced in response to seizure activity, was up-regulated in the Scn1b-null brain at P16 but not at P5. Consistent with this, epileptiform activity was observed in hippocampal and cortical slices prepared from the P16 but not from the P5-P7 Scn1b-null brain. On the basis of these results, we investigated neuronal pathfinding at P5. We observed disrupted fasciculation of parallel fibers in the P5 null cerebellum. Further, P5 null mice showed reduced neuron density in the dentate gyrus granule cell layer, increased proliferation of granule cell precursors in the hilus, and defective axonal extension and misorientation of somata and processes of inhibitory neurons in the dentate gyrus and CA1. Thus, Scn1b is critical for neuronal proliferation, migration, and pathfinding during the critical postnatal period of brain development. We propose that defective neuronal proliferation, migration, and pathfinding in response to Scn1b deletion may contribute to the development of hyperexcitability. PMID:23277545

Brackenbury, William J; Yuan, Yukun; O'Malley, Heather A; Parent, Jack M; Isom, Lori L

2013-01-15

179

Imaging brain neuronal activity using functionalized magnetonanoparticles and MRI.  

PubMed

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

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

2012-10-01

180

Sensory stimulation induces tensor fields, which specifically transform brain activity.  

PubMed

It was recently shown that brain activity can be represented as a stimulation-specific vector field. Since the vector field of brain activity is specifically transformed by sensory input, we suggested that a tensor field that transforms brain activity reflects sensory input. We calculated the tensor fields that transform brain activity between visual baseline and auditory word processing in PET data and between environmental sounds and auditory word processing in fMRI data. In the first comparison, significant clusters formed a distributed network over the brain cortex. In the second comparison, clusters were more localised in the temporo-frontal network of speech processing. Our study therefore demonstrated that tensor fields reflect the sensory input that specifically transforms brain activity. PMID:24012681

Strelnikov, Kuzma

2013-10-25

181

Brain structural and functional abnormalities in mood disorders: implications for neurocircuitry models of depression  

PubMed Central

The neural networks that putatively modulate aspects of normal emotional behavior have been implicated in the pathophysiology of mood disorders by converging evidence from neuroimaging, neuropathological and lesion analysis studies. These networks involve the medial prefrontal cortex (MPFC) and closely related areas in the medial and caudolateral orbital cortex (medial prefrontal network), amygdala, hippocampus, and ventromedial parts of the basal ganglia, where alterations in grey matter volume and neurophysiological activity are found in cases with recurrent depressive episodes. Such findings hold major implications for models of the neurocircuits that underlie depression. In particular evidence from lesion analysis studies suggests that the MPFC and related limbic and striato-pallido-thalamic structures organize emotional expression. The MPFC is part of a larger “default system” of cortical areas that include the dorsal PFC, mid- and posterior cingulate cortex, anterior temporal cortex, and entorhinal and parahippocampal cortex, which has been implicated in self-referential functions. Dysfunction within and between structures in this circuit may induce disturbances in emotional behavior and other cognitive aspects of depressive syndromes in humans. Further, because the MPFC and related limbic structures provide forebrain modulation over visceral control structures in the hypothalamus and brainstem, their dysfunction can account for the disturbances in autonomic regulation and neuroendocrine responses that are associated with mood disorders. This paper discusses these systems together with the neurochemical systems that impinge on them and form the basis for most pharmacological therapies.

Price, Joseph L.; Furey, Maura L.

2008-01-01

182

Do Exercise and Physical Activity Protect the Brain?  

MedlinePLUS

... and Physical Activity Protect the Brain? Exercise and physical activity have many benefits. Studies show they are good ... a healthy lifestyle that includes a healthy diet, physical activity, appropriate weight, and not smoking can maintain and ...

183

The use of in utero MRI to supplement ultrasound in the foetus at high risk of developmental brain or spine abnormality  

PubMed Central

Objectives It is widely accepted that the diagnosis of foetal central nervous system (CNS) abnormalities can be improved by performing MRI examinations in utero. Most of the published literature has concentrated on pregnancies in which a developmental abnormality has been detected (or suspected) on ultrasound in an otherwise low-risk pregnancy. In this paper, we test the hypothesis that in utero MRI of the foetal brain in high-risk pregnancies will detect abnormalities not shown by ultrasound at a rate that justifies its use in clinical practice. Methods 100 females were recruited into the study from foeto-maternal or clinical genetic departments. They all had a foetus/child with a CNS malformation from an earlier pregnancy, which led to an increased risk of recurrence being quoted for the present pregnancy. All in utero MRI examinations were performed on 1.5 T clinical MRI systems at 18 weeks gestational age or later. Results In 78% of cases, the ultrasound and MRI results agreed and showed no abnormality. In 13%, ultrasound and MRI described identical abnormal findings. In 9%, the ultrasound and MRI examinations had discrepant findings; in all these cases the MRI findings described more serious CNS pathology. The effects on management were judged to be major, by at least one assessor, in 7/9 of those cases. Conclusion As in many other situations involving antenatal detection of CNS abnormalities, in utero MRI should be considered in females with increased risk of foetal CNS malformation based on the results of an earlier pregnancy. Advances in knowledge In utero MRI of the foetus has an important role in antenatal diagnosis of females carrying a foetus with an increased risk of a brain abnormality.

Griffiths, P D; Porteous, M; Mason, G; Russell, S; Morris, J; Fanou, E M; Reeves, M J

2012-01-01

184

On a Quantum Model of Brain Activities  

NASA Astrophysics Data System (ADS)

One of the main activities of the brain is the recognition of signals. A first attempt to explain the process of recognition in terms of quantum statistics was given in [6]. Subsequently, details of the mathematical model were presented in a (still incomplete) series of papers (cf. [7, 2, 5, 10]). In the present note we want to give a general view of the principal ideas of this approach. We will introduce the basic spaces and justify the choice of spaces and operations. Further, we bring the model face to face with basic postulates any statistical model of the recognition process should fulfill. These postulates are in accordance with the opinion widely accepted in psychology and neurology.

Fichtner, K.-H.; Fichtner, L.; Freudenberg, W.; Ohya, M.

2010-01-01

185

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

Microsoft Academic Search

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

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

1995-01-01

186

Electrophysiological Imaging of Brain Activity and Connectivity - Challenges and Opportunities  

PubMed Central

Unlocking the dynamic inner workings of the brain continues to remain a grand challenge of the 21st century. To this end, functional neuroimaging modalities represent an outstanding approach to better understand the mechanisms of both normal and abnormal brain function. The ability to image brain function with ever increasing spatial and temporal resolution utilizing minimal or non-invasive procedures has made a significant leap over the past several decades. Further delineation of functional networks could lead to improved understanding of brain function in both normal as well as diseased states. This article reviews recent advancements and current challenges in dynamic functional neuroimaging techniques, including electrophysiological source imaging, multimodal neuroimaging integrating fMRI with EEG/MEG, and functional connectivity imaging.

He, Bin; Yang, Lin; Wilke, Christopher; Yuan, Han

2011-01-01

187

Abnormal expression of transcription factor activator protein-2? in pathologic placentas.  

PubMed

Recent studies from our laboratory have indicated that the transcription factor activator protein-2? plays a critical role in the differentiation of human villous cytotrophoblast cells to syncytiotrophoblast cells. However, little is known about the expression of activator protein-2? in placentas from pathologic pregnancies. This study compares the expression of activator protein-2? in placentas from high-risk pregnancies to gestational age-matched controls. Paracentral sections from grossly unremarkable areas of 10 placentas from each group of pregnancies complicated by mild preeclampsia, severe preeclampsia, diabetes mellitus, chronic hypertension, and fetal growth restriction and 10 control cases of placentas from normal pregnancies matched for gestational age were double immunostained for activator protein-2? and E-cadherin. The total numbers of cytotrophoblast cells and syncytiotrophoblast nuclei and the numbers of activator protein-2?-positive and activator protein-2?-negative nuclei in both of these cell types were counted by 2 pathologists blinded to disease status, in 10 representative×40 high-power fields for each placenta. Abnormal placental maturation in most of pathologic pregnancies was evidenced by a 1.5- to 1.7-fold lower expression ratio of syncytiotrophoblast cell to cytotrophoblast cell. Activator protein-2? in syncytiotrophoblast cells was lower in mild preeclampsia, diabetes mellitus, hypertension, and fetal growth restriction (P<.0001 in each instance) and was higher by 2-fold in severe preeclampsia, although this increase was not statistically significant (P=.3). Because activator protein-2? has been shown to be critical for villous cytotrophoblast cell differentiation, our findings suggest that abnormalities in the activator protein-2? cascade of transcription factors and/or signaling molecules may contribute to the pathogenesis of the abnormal maturation in placentas in certain types of high-risk pregnancies. The different pattern of activator protein-2? expression in mild and severe preeclampsia clearly suggests that these conditions may have 2 independent pathogenic mechanisms. PMID:22575257

Sheridan, Rachel M; Stanek, Jerzy; Khoury, Jane; Handwerger, Stuart

2012-11-01

188

The Effects of Aerobic Activity on Brain Structure  

PubMed Central

Aerobic activity is a powerful stimulus for improving mental health and for generating structural changes in the brain. We review the literature documenting these structural changes and explore exactly where in the brain these changes occur as well as the underlying substrates of the changes including neural, glial, and vasculature components. Aerobic activity has been shown to produce different types of changes in the brain. The presence of novel experiences or learning is an especially important component in how these changes are manifest. We also discuss the distinct time courses of structural brain changes with both aerobic activity and learning as well as how these effects might differ in diseased and elderly groups.

Thomas, Adam G.; Dennis, Andrea; Bandettini, Peter A.; Johansen-Berg, Heidi

2011-01-01

189

Phospholipase A2 activity is associated with structural brain changes in schizophrenia.  

PubMed

Regional structural brain changes are among the most robust biological findings in schizophrenia, yet the underlying pathophysiological changes remain poorly understood. Recent evidence suggests that abnormal neuronal/dendritic plasticity is related to alterations in membrane lipids. We examined whether serum activity of membrane lipid remodelling/repairing cytosolic phospholipase A(2) (PLA(2)) were related to regional brain structure in magnetic resonance images (MRI). The study involved 24 schizophrenia patients, who were either drug-naïve or off antipsychotic medication, and 25 healthy controls. Using voxel-based morphometry (VBM) analysis of T1-high-resolution MRI-images, we correlated both gray matter and white matter changes with serum PLA(2)-activity. PLA(2) activity was increased in patients, consistent with previous findings. VBM group comparison of patients vs. controls showed abnormalities of frontal and medial temporal cortices/hippocampus, and left middle/superior temporal gyrus in first-episode patients. Group comparison of VBM/PLA(2)-correlations revealed a distinct pattern of disease-related interactions between gray/white matter changes in patients and PLA(2)-activity: in first-episode patients (n=13), PLA(2)-activity was associated with structural alterations in the left prefrontal cortex and the bilateral thalamus. Recurrent-episode patients (n=11) showed a wide-spread pattern of associations between PLA(2)-activity and structural changes in the left (less right) prefrontal and inferior parietal cortex, the left (less right) thalamus and caudate nucleus, the left medial temporal and orbitofrontal cortex and anterior cingulum, and the cerebellum. Our findings demonstrate a potential association between membrane lipid biochemistry and focal brain structural abnormalities in schizophrenia. Differential patterns in first-episode vs. chronic patients might be related to PLA(2)-increase at disease-onset reflecting localized regenerative activity, whereas correlations in recurrent-episode patients might point to less specific neurodegenerative aspects of disease progression. PMID:20478385

Smesny, Stefan; Milleit, Berko; Nenadic, Igor; Preul, Christoph; Kinder, Daniel; Lasch, Jürgen; Willhardt, Ingo; Sauer, Heinrich; Gaser, Christian

2010-10-01

190

Role of Social Encounter-Induced Activation of Prefrontal Serotonergic Systems in the Abnormal Behaviors of Isolation-Reared Mice  

PubMed Central

Isolation-reared male rodents show abnormal behaviors such as hyperlocomotion, aggressive behaviors, deficits of prepulse inhibition, and depression- and anxiety-like behaviors, but the neurochemical mechanism for the effects of psychological stress in these animals is not fully understood. This study examined the effects of social interactions between isolation-reared mice and intruder mice on brain monoaminergic systems. A cage was divided into two compartments by a mesh partition to prevent direct physical interactions. The 20-min encounter with an intruder elicited a restless and hyperexcitable state (hyperactivity) in male, but not in female, isolation-reared mice, whereas encounters with a sleeping intruder or a novel object did not. Although the encounter did not affect prefrontal neuronal-activity-marker c-Fos expression, dopamine (DA) levels, or serotonin (5-HT) levels in male group-reared mice or female isolation-reared mice, it increased prefrontal c-Fos expression, DA levels, and 5-HT levels in male isolation-reared mice. Furthermore, encounter-induced increases in c-Fos expression in the dorsal raphe nucleus and ventral tegmental area, but not in the nucleus accumbens shell, were much greater in isolation-reared than group-reared male mice. A 5-HT1A receptor agonist, a metabotropic glutamate 2/3 receptor agonist, and a gamma-aminobutyric acid A receptor agonist attenuated isolation-induced aggressive behaviors and encounter-induced hyperactivity, c-Fos expression in the prefrontal cortex and dorsal raphe nucleus, and increases in prefrontal 5-HT levels. These findings suggest that the prefrontal DA and 5-HT systems are activated by encounter stimulation in male isolation-reared mice, and the encounter-induced activation of 5-HT system triggers the induction of some abnormal behaviors in male isolation-reared mice. Furthermore, this study implies that the encounter stimulation-induced signal has a pharmacological significance.

Ago, Yukio; Araki, Ryota; Tanaka, Tatsunori; Sasaga, Asuka; Nishiyama, Saki; Takuma, Kazuhiro; Matsuda, Toshio

2013-01-01

191

Abnormal pontine activation in pathological laughing as shown by functional magnetic resonance imaging  

PubMed Central

To explore the aetiology of pathological laughing, a 65?year?old woman with pathological laughing was examined by 3?T functional magnetic resonance imaging (fMRI) before and after treatment with drugs. Here, we report that the patient consistently showed exaggerated pontine activation during the performance of three tasks before treatment, whereas abnormal pontine activation was no longer found after successful treatment with the selective serotonin reuptake inhibitor, paroxetine. Our findings in this first fMRI study of pathological laughing suggest that serotonergic replacement decreases the aberrant activity in a circuit that involves the pons.

Kosaka, H; Omata, N; Omori, M; Shimoyama, T; Murata, T; Kashikura, K; Takahashi, T; Murayama, J; Yonekura, Y; Wada, Y

2006-01-01

192

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.

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

193

High prevalence of chronic pituitary and target-organ hormone abnormalities after blast-related mild traumatic brain injury.  

PubMed

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

2012-01-01

194

Potential Moderators of Physical Activity on Brain Health  

PubMed Central

Age-related cognitive decline is linked to numerous molecular, structural, and functional changes in the brain. However, physical activity is a promising method of reducing unfavorable age-related changes. Physical activity exerts its effects on the brain through many molecular pathways, some of which are regulated by genetic variants in humans. In this paper, we highlight genes including apolipoprotein E (APOE), brain derived neurotrophic factor (BDNF), and catechol-O-methyltransferase (COMT) along with dietary omega-3 fatty acid, docosahexaenoic acid (DHA), as potential moderators of the effect of physical activity on brain health. There are a growing number of studies indicating that physical activity might mitigate the genetic risks for disease and brain dysfunction and that the combination of greater amounts of DHA intake with physical activity might promote better brain function than either treatment alone. Understanding whether genes or other lifestyles moderate the effects of physical activity on neurocognitive health is necessary for delineating the pathways by which brain health can be enhanced and for grasping the individual variation in the effectiveness of physical activity interventions on the brain and cognition. There is a need for future research to continue to assess the factors that moderate the effects of physical activity on neurocognitive function.

Leckie, Regina L.; Weinstein, Andrea M.; Hodzic, Jennifer C.; Erickson, Kirk I.

2012-01-01

195

Cerebral blood volume changes during brain activation  

PubMed Central

Cerebral blood volume (CBV) changes significantly with brain activation, whether measured using positron emission tomography, functional magnetic resonance imaging (fMRI), or optical microscopy. If cerebral vessels are considered to be impermeable, the contents of the skull incompressible, and the skull itself inextensible, task- and hypercapnia-related changes of CBV could produce intolerable changes of intracranial pressure. Because it is becoming clear that CBV may be useful as a well-localized marker of neural activity changes, a resolution of this apparent paradox is needed. We have explored the idea that much of the change in CBV is facilitated by exchange of water between capillaries and surrounding tissue. To this end, we developed a novel hemodynamic boundary-value model and found approximate solutions using a numerical algorithm. We also constructed a macroscopic experimental model of a single capillary to provide biophysical insight. Both experiment and theory model capillary membranes as elastic and permeable. For a realistic change of input pressure, a relative pipe volume change of 21±5% was observed when using the experimental setup, compared with the value of approximately 17±1% when this quantity was calculated from the mathematical model. Volume, axial flow, and pressure changes are in the expected range.

Krieger, Steffen Norbert; Streicher, Markus Nikolar; Trampel, Robert; Turner, Robert

2012-01-01

196

Decreased activation and increased lateralization in brain functioning for selective attention and response inhibition in adolescents with spina bifida.  

PubMed

We used functional magnetic resonance imaging to evaluate functional activity in the brain of adolescents with spina bifida when performing selective attention and response inhibition tasks. We then compared the results to that of age-matched controls. Our results showed that adolescents with spina bifida had decreased frontal and superior parietal activation and more apparently low involvement of left brain hemisphere during these tasks. Our results indicated activation deficits and possibly abnormal functional organization in adolescents with spina bifida and associated pathologies such as hydrocephalus. PMID:22145814

Ou, Xiawei; Snow, Jeffrey H; Byerley, Amy K; Hall, John J; Glasier, Charles M

2013-01-01

197

Network-dependent modulation of brain activity during sleep.  

PubMed

Brain activity dynamically changes even during sleep. A line of neuroimaging studies has reported changes in functional connectivity and regional activity across different sleep stages such as slow-wave sleep (SWS) and rapid-eye-movement (REM) sleep. However, it remains unclear whether and how the large-scale network activity of human brains changes within a given sleep stage. Here, we investigated modulation of network activity within sleep stages by applying the pairwise maximum entropy model to brain activity obtained by functional magnetic resonance imaging from sleeping healthy subjects. We found that the brain activity of individual brain regions and functional interactions between pairs of regions significantly increased in the default-mode network during SWS and decreased during REM sleep. In contrast, the network activity of the fronto-parietal and sensory-motor networks showed the opposite pattern. Furthermore, in the three networks, the amount of the activity changes throughout REM sleep was negatively correlated with that throughout SWS. The present findings suggest that the brain activity is dynamically modulated even in a sleep stage and that the pattern of modulation depends on the type of the large-scale brain networks. PMID:24814208

Watanabe, Takamitsu; Kan, Shigeyuki; Koike, Takahiko; Misaki, Masaya; Konishi, Seiki; Miyauchi, Satoru; Miyahsita, Yasushi; Masuda, Naoki

2014-09-01

198

Altered Spontaneous Brain Activity in Primary Open Angle Glaucoma: A Resting-State Functional Magnetic Resonance Imaging Study  

PubMed Central

Background Previous studies demonstrated that primary open angle glaucoma (POAG) is associated with abnormal brain structure; however, little is known about the changes in the local synchronization of spontaneous activity. The main objective of this study was to investigate spontaneous brain activity in patients with POAG using regional homogeneity (ReHo) analysis based on resting state functional magnetic resonance imaging (rs-fMRI). Methodology/Principal Findings Thirty-nine POAG patients and forty-one age- and gender- matched healthy controls were finally included in the study. ReHo values were used to evaluate spontaneous brain activity and whole brain voxel-wise analysis of ReHo was carried out to detect differences by region in spontaneous brain activity between groups. Compared to controls, POAG patients showed increased ReHo in the right dorsal anterior cingulated cortex, the bilateral medial frontal gyrus and the right cerebellar anterior lobe, and decreased ReHo in the bilateral calcarine, bilateral precuneus gryus, bilateral pre/postcentral gyrus, left inferior parietal lobule and left cerebellum posterior lobe. A multiple linear regression analysis was performed to explore the relationships between clinical measures and ReHo by region showed significant group differences in the POAG group. Negative correlations were found between age and the ReHo values of the superior frontal gyrus (r?=??0.323, p?=?0.045), left calcarine (r?=??0.357, p?=?0.026) and inferior parietal lobule (r?=??0.362, p?=?0.024). A negative correlation was found between the ReHo values of the left precuneus and the cumulative mean defect (r?=??0.400, p?=?0.012). Conclusions POAG was associated with abnormal brain spontaneous activity in some brain regions and such changed regional activity may be associated with clinical parameters. Spontaneous brain activity may play a role in POAG initiation and progression.

Lin, Fuchun; Chen, Zhiqi; Yan, Xiaoqin; Hao, Yonghong; Zhu, Wenzhen; Zhang, Hong

2014-01-01

199

Resting brain activity: differences between genders.  

PubMed

This study investigated electrophysiological (EEG) and hemodynamic (near infrared spectroscopy - NIRS) measures as a function of gender in normal adult individuals. The EEG data analysis was based on the resting eyes closed brain activity of 300 respondents (160 females). The NIRS analyses was based on 155 respondents (88 females). The total power, coherence and approximate entropy measures were calculated for the EEG recordings in the ?, ?, lower-1 ?, lower-2 ?, upper ?, ? and ? bands. Based on the filtered NIRS data the concentration, the peak frequency and the Hurst exponent (H) of oxi-Hb and deoxi-Hb were determined. Higher power values in females as compared with males were observed in the ? and ? bands. In the lower-1 ?, lower-2 ? and upper ? bands this difference was only pronounced in the parieto-occipital areas. Higher coherences in the ? band in females as compared to males was observed, whereas a reverse pattern of differences was present in the ? and ? bands. A similar pattern of differences was also observed for the ApEn measures. Males showed a higher percentage of oxygen saturation of hemoglobin, more irregular and faster spontaneous fluctuations in oxi-Hb and deoxi-Hb as compared with females. It can be concluded that males and females differ in the local as well as long range coding of information - the binding of distributed responses - as well as in the excitability dynamics of their cortical network. PMID:20875436

Jausovec, Norbert; Jausovec, Ksenija

2010-11-01

200

Brain activity of women is more fractal than men.  

PubMed

Investigating gender differences of the brain is of both scientific and clinical importance, as understanding such differences may be helpful for improving gender specific treatments of neuropsychiatric disorders. As brain is a highly complex system, it is crucial to investigate its activity in terms of nonlinear dynamics. However, there are few studies that investigated gender differences based on dynamical characteristics of the brain. Fractal dimension (FD) is a key characteristic of the brain dynamics which indicates the level of complexity on which the neuronal regions function or interact and quantifies the associated brain processes on a scale ranging from fully deterministic to fully random. This study investigates the gender differences of brain dynamics, comparing fractal dimension of scalp EEGs (in eyes-closed resting state) of 34 female and 34 male healthy adults. The results showed significantly greater FDs in females compared to males in all brain regions except in lateral and occipital lobes. This indicates a higher complexity of the brain dynamics in females relative to males. The high accuracies of 87.8% and 93.1% obtained by logistic regression and enhanced probabilistic neural network, respectively, in discriminating between the gender groups based on the FDs also confirmed the great gender differences of complexity of brain activities. The results showed that delta, alpha, and beta bands are the frequency bands that contribute most to the gender differences in brain complexity. Furthermore, the lateralization analysis showed the leftward lateralization of complexity in females is greater than in males. PMID:23313595

Ahmadi, Khodabakhsh; Ahmadlou, Mehran; Rezazade, Majid; Azad-Marzabadi, Esfandiar; Sajedi, Firoozeh

2013-02-22

201

Repetitive Transcranial Magnetic Stimulation Activates Specific Regions in Rat Brain  

Microsoft Academic Search

Repetitive transcranial magnetic stimulation (rTMS) is a noninvasive technique to induce electric currents in the brain. Although rTMS is being evaluated as a possible alternative to electroconvulsive therapy for the treatment of refractory depression, little is known about the pattern of activation induced in the brain by rTMS. We have compared immediate early gene expression in rat brain after rTMS

Ru-Rong Ji; Carlos D. Aizenman; Charles M. Epstein; Dike Qiu; Justin C. Huang; Fabio Rupp

1998-01-01

202

Effects of a carbohydrate supplement upon resting brain activity  

Microsoft Academic Search

Glucose is a major energy source for the brain, and along with several monosaccharide derivatives as components of brain gangliosides,\\u000a they play important roles in neurologic function. However, there is little information available on the role of glucose and\\u000a other monosaccharides on resting brain activity. This study was designed to evaluate the effects of a single dose of a carbohydrate

Chenghua Wang; Joanne S. Szabo; Roscoe A. Dykman

2004-01-01

203

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.

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; Gonzalez, R. Gilberto

2011-01-01

204

Increased glial metabolites predict increased working memory network activation in HIV brain injury.  

PubMed

Deficits in attention and working memory are common in human immuno deficiency virus type 1 (HIV-1)-infected patients, but the pathophysiology of these deficits is poorly understood. Modern neuroimaging techniques, such as proton magnetic resonance spectroscopy ((1)H MRS) and functional MRI (fMRI), can assess some of the processes underlying HIV brain injury. To evaluate the model that attentional deficits in early HIV brain disease are related to brain inflammation, (1)H MRS and fMRI were performed in 14 HIV-positive subjects [acquired immunodeficiency syndrome (AIDS) dementia complex stage 1 or less]. Increasing attentional load on three working memory tasks was assessed with fMRI, and the concentrations of brain metabolites were measured with (1)H MRS in the frontal gray and white matter, and basal ganglia. Metabolite concentrations were correlated with fMRI blood oxygenation level-dependent (BOLD) signals, using a random-effects linear regression model in SPM99. Several positive correlations were observed between the BOLD signal strength in the working memory network (posterior parietal cortex and lateral prefrontal cortex) and the concentrations of frontal white matter and basal ganglia metabolites that are predominant in glial cells (choline-containing compounds, myo-inositol, and total creatine). In contrast, BOLD signals in the working memory network were not correlated with the concentration of N-acetyl compounds, which are markers of neuronal viability, or with metabolite concentrations in the frontal gray matter. These findings are consistent with previous results that mild HIV brain injury is associated with increased glial activation without major involvement of neuronal abnormalities. We propose that the inflammatory glial abnormalities reduce the efficiency of neural processing, and necessitate compensatory increases in attention in patients, and associated BOLD signals, to perform a given task. The same mechanism may also contribute to cognitive dysfunction in other brain diseases that involve inflammation. PMID:12948723

Ernst, T; Chang, L; Arnold, S

2003-08-01

205

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.

He, Biyu J.

2013-01-01

206

Brain activation during mental rotation in school children and adults  

Microsoft Academic Search

Summary  Mental rotation is a complex cognitive skill depending on the manipulation of mental representations. We aimed to investigate\\u000a the maturing neuronal network for mental rotation by measuring brain activation in 20 children and 20 adults using functional\\u000a magnetic resonance imaging. Our results indicate that brain activation patterns are very similar between children and adults.\\u000a However, adults exhibit stronger activation in

K. Kucian; M. von Aster; T. Loenneker; T. Dietrich; F. W. Mast; E. Martin

2007-01-01

207

Predicting Human Brain Activity Associated with the Meanings of Nouns  

Microsoft Academic Search

The question of how the human brain represents conceptual knowledge has been debated in many scientific fields. Brain imaging studies have shown that different spatial patterns of neural activation are associated with thinking about different semantic categories of pictures and words (for example, tools, buildings, and animals). We present a computational model that predicts the functional magnetic resonance imaging (fMRI)

Tom M. Mitchell; Svetlana V. Shinkareva; Andrew Carlson; Kai-Min Chang; Vicente L. Malave; Robert A. Mason; Marcel Adam Just

2008-01-01

208

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

209

Understanding Brain Tumors  

MedlinePLUS

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

210

Physical activity, inflammation, and volume of the aging brain.  

PubMed

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±4.8years) and 39 patients with AD (81.9±5.1years 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 9years and TNF? over 3years 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

2014-07-25

211

Focused ultrasound modulates region-specific brain activity  

PubMed Central

We demonstrated the in vivo feasibility of using focused ultrasound (FUS) to transiently modulate (through either stimulation or suppression) the function of regional brain tissue in rabbits. FUS was delivered in a train of pulses at low acoustic energy, far below the cavitation threshold, to the animal's somatomotor and visual areas, as guided by anatomical and functional information from magnetic resonance imaging (MRI). The temporary alterations in the brain function affected by the sonication were characterized by both electrophysiological recordings and functional brain mapping achieved through the use of functional MRI (fMRI). The modulatory effects were bimodal, whereby the brain activity could either be stimulated or selectively suppressed. Histological analysis of the excised brain tissue after the sonication demonstrated that the FUS did not elicit any tissue damages. Unlike transcranial magnetic stimulation, FUS can be applied to deep structures in the brain with greater spatial precision. Transient modulation of brain function using image-guided and anatomically-targeted FUS would enable the investigation of functional connectivity between brain regions and will eventually lead to a better understanding of localized brain functions. It is anticipated that the use of this technology will have an impact on brain research and may offer novel therapeutic interventions in various neurological conditions and psychiatric disorders.

Yoo, Seung-Schik; Bystritsky, Alexander; Lee, Jong-Hwan; Zhang, Yongzhi; Fischer, Krisztina; Min, Byoung-Kyong; McDannold, Nathan J.; Pascual-Leone, Alvaro; Jolesz, Ferenc A.

2012-01-01

212

Focused ultrasound modulates region-specific brain activity.  

PubMed

We demonstrated the in vivo feasibility of using focused ultrasound (FUS) to transiently modulate (through either stimulation or suppression) the function of regional brain tissue in rabbits. FUS was delivered in a train of pulses at low acoustic energy, far below the cavitation threshold, to the animal's somatomotor and visual areas, as guided by anatomical and functional information from magnetic resonance imaging (MRI). The temporary alterations in the brain function affected by the sonication were characterized by both electrophysiological recordings and functional brain mapping achieved through the use of functional MRI (fMRI). The modulatory effects were bimodal, whereby the brain activity could either be stimulated or selectively suppressed. Histological analysis of the excised brain tissue after the sonication demonstrated that the FUS did not elicit any tissue damages. Unlike transcranial magnetic stimulation, FUS can be applied to deep structures in the brain with greater spatial precision. Transient modulation of brain function using image-guided and anatomically-targeted FUS would enable the investigation of functional connectivity between brain regions and will eventually lead to a better understanding of localized brain functions. It is anticipated that the use of this technology will have an impact on brain research and may offer novel therapeutic interventions in various neurological conditions and psychiatric disorders. PMID:21354315

Yoo, Seung-Schik; Bystritsky, Alexander; Lee, Jong-Hwan; Zhang, Yongzhi; Fischer, Krisztina; Min, Byoung-Kyong; McDannold, Nathan J; Pascual-Leone, Alvaro; Jolesz, Ferenc A

2011-06-01

213

Diagnosis of Heyde's syndrome by abnormal closure times despite normal von Willebrand's activity.  

PubMed

Heyde's syndrome is characterized by iron deficiency anemia due to gastrointestinal bleeding and calcific aortic stenosis. Patients with this syndrome have a bleeding diathesis due to a loss of the largest multimers of von Willebrand factor (vWF). Here we present a case of Heyde's syndrome diagnosed with abnormal closure times and normal vWF Ristocetin cofactor activity (vWF:Rco). In this case, a 79-year-old man with known aortic stenosis and recurrent gastrointestinal bleeding was cured of a life-threatening hemorrhage after the replacement of his stenotic aortic valve. Factor VIII activity (1.53 ?IU/ml), vWF antigen (1.26 ?IU/ml), vWF:Rco (1.11? IU/?ml), and the ratio of vWF antigen/vWF:Rco (0.88) were all within normal limits. Instead, to prove a defect in platelet aggregation, closure times measured with collagen/ADP and collagen/epinephrine were abnormal (>300 ?s). Postoperatively, these closure times normalized. What is unique about our current report is that we measured both vWF:Rco and closure times, the two readily available assays in most coagulation laboratories. vWF:Rco is a standard assay for measuring platelet activity but may miss defects in platelet aggregation that are only seen under high shear stress. As the closure times can detect such defects, it is perhaps more representative than traditional assays, and in situations such as our case, closure times may be the only method by which subtle abnormalities in vWF function could be detected. PMID:21760480

D'Souza, Pernilla M; Blostein, Mark D

2011-10-01

214

Abnormal gamma and beta MEG activity during finger movements in early onset psychosis  

PubMed Central

Patients with psychosis often exhibit abnormalities in basic motor control, but little is known about the neural basis of these deficits. This study examines the neuro-dynamics of movement using magnetoencephalography (MEG) in adolescents with early-onset psychosis and typically-developing controls. MEG data were imaged using beamforming then evaluated for task and group effects before, during, and after movement onsets. Primary findings included weaker activation in patients during movement execution in cerebellar cortices. Such aberrations likely contribute to the decreased motor control exhibited by patients with psychosis, and may reflect GABAergic-based inhibitory deficits comparable to those seen in cellular and system-level studies.

Wilson, Tony W.; Slason, Erin; Asherin, Ryan; Kronberg, Eugene; Teale, Peter D.; Reite, Martin L.; Rojas, Donald C.

2011-01-01

215

Modeling “psychosis” in vitro by inducing disordered neuronal network activity in cortical brain slices  

Microsoft Academic Search

Introduction  Dysregulation of neuronal networks has been suggested to underlie the cognitive and perceptual abnormalities observed schizophrenia.\\u000a \\u000a \\u000a \\u000a Discussions  An in vitro model of psychosis is proposed based on the two different approaches to cause aberrant network activity in layer\\u000a V pyramidal cells of prefrontal brain slices: (1) psychedelic hallucinogens such as lysergic acid diethylamide and (2) minimal\\u000a GABAA receptor antagonism, modeling the

George K. Aghajanian

2009-01-01

216

A Two-Stage Model for In Vivo Assessment of Brain Tumor Perfusion and Abnormal Vascular Structure Using Arterial Spin Labeling  

PubMed Central

The ability to assess brain tumor perfusion and abnormalities in the vascular structure in vivo could provide significant benefits in terms of lesion diagnosis and assessment of treatment response. Arterial spin labeling (ASL) has emerged as an increasingly viable methodology for non-invasive assessment of perfusion. Although kinetic models have been developed to describe perfusion in healthy tissue, the dynamic behaviour of the ASL signal in the brain tumor environment has not been extensively studied. We show here that dynamic ASL data acquired in brain tumors displays an increased level of ‘biphasic’ behaviour, compared to that seen in healthy tissue. A new two-stage model is presented which more accurately describes this behaviour, and provides measurements of perfusion, pre-capillary blood volume fraction and transit time, and capillary bolus arrival time. These biomarkers offer a novel contrast in the tumor and surrounding tissue, and provide a means for measuring tumor perfusion and vascular structural abnormalities in a fully non-invasive manner.

Hales, Patrick W.; Phipps, Kim P.; Kaur, Ramneek; Clark, Christopher A.

2013-01-01

217

Regional Brain Activation during Hypoglycemia in Type 1 Diabetes  

PubMed Central

Context: Mechanisms underlying the brain response to hypoglycemia are not well understood. Objective: Our objective was to determine the blood glucose level at which the hypothalamus and other brain regions are activated in response to hypoglycemia in type 1 diabetic patients and control subjects. Design: This was a cross-sectional study evaluating brain activity using functional magnetic resonance imaging in conjunction with a hyperinsulinemic hypoglycemic clamp to lower glucose from euglycemia (90 mg/dl) to hypoglycemia (50 mg/dl). Setting: The study was performed at the Brain Imaging Center in the McLean Hospital. Study Participants: Seven type 1 diabetic patients between 18 and 50 yr old and six matched control subjects were included in the study. Intervention: Hyperinsulinemic hypoglycemic clamp was performed. Main Outcome Measures: Blood glucose level at peak hypothalamic activation, amount of regional brain activity during hypoglycemia in both groups, and difference in regional brain activation between groups were calculated. Results: The hypothalamic region activates at 68 ± 9 mg/dl in control subjects and 76 ± 8 mg/dl in diabetic patients during hypoglycemia induction. Brainstem, anterior cingulate cortex, uncus, and putamen were activated in both groups (P < 0.001). Each group also activated unique brain areas not active in the other group. Conclusions: This application of functional magnetic resonance imaging can be used to identify the glucose level at which the hypothalamus is triggered in response to hypoglycemia and whether this threshold differs across patient populations. This study suggests that a core network of brain regions is recruited during hypoglycemia in both diabetic patients and control subjects.

Musen, Gail; Simonson, Donald C.; Bolo, Nicolas R.; Driscoll, Amy; Weinger, Katie; Raji, Annaswamy; Theberge, Jean; Renshaw, Perry F.; Jacobson, Alan M.

2008-01-01

218

Abnormal cortical sensorimotor activity during "Target" sound detection in subjects with acute acoustic trauma sequelae: an fMRI study  

PubMed Central

The most common consequences of acute acoustic trauma (AAT) are hearing loss at frequencies above 3 kHz and tinnitus. In this study, we have used functional Magnetic Resonance Imaging (fMRI) to visualize neuronal activation patterns in military adults with AAT and various tinnitus sequelae during an auditory “oddball” attention task. AAT subjects displayed overactivities principally during reflex of target sound detection, in sensorimotor areas and in emotion-related areas such as the insula, anterior cingulate and prefrontal cortex, in premotor area, in cross-modal sensory associative areas, and, interestingly, in a region of the Rolandic operculum that has recently been shown to be involved in tympanic movements due to air pressure. We propose further investigations of this brain area and fine middle ear investigations, because our results might suggest a model in which AAT tinnitus may arise as a proprioceptive illusion caused by abnormal excitability of middle-ear muscle spindles possibly link with the acoustic reflex and associated with emotional and sensorimotor disturbances.

Job, Agnes; Pons, Yoann; Lamalle, Laurent; Jaillard, Assia; Buck, Karl; Segebarth, Christoph; Delon-Martin, Chantal

2012-01-01

219

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

220

Enzymatically active lysosomal proteases are associated with amyloid deposits in Alzheimer brain.  

PubMed Central

The formation of beta-amyloid in the brains of individuals with Alzheimer disease requires the proteolytic cleavage of a membrane-associated precursor protein. The proteases that may be involved in this process have not yet been identified. Cathepsins are normally intracellular proteolytic enzymes associated with lysosomes; however, when sections from Alzheimer brains were stained by antisera to cathepsin D and cathepsin B, high levels of immunoreactivity were also detected in senile plaques. Extracellular sites of cathepsin immunoreactivity were not seen in control brains from age-matched individuals without neurologic disease or from patients with Huntington disease or Parkinson disease. In situ enzyme histochemistry of cathepsin D and cathepsin B on sections of neocortex using synthetic peptides and protein substrates showed that senile plaques contained the highest levels of enzymatically active cathepsin. At the ultrastructural level, cathepsin immunoreactivity in senile plaques was localized principally to lysosomal dense bodies and lipofuscin granules, which were extracellular. Similar structures were abundant in degenerating neurons of Alzheimer neocortex, and cathepsin-laden neuronal perikarya in various stages of disintegration could be seen within some senile plaques. The high levels of enzymatically competent lysosomal proteases abnormally localized in senile plaques represent evidence for candidate enzymes that may mediate the proteolytic formation of amyloid. We propose that amyloid precursor protein within senile plaques is processed by lysosomal proteases principally derived from degenerating neurons. Escape of cathepsins from the stringently regulated intracellular milieu provides a basis for an abnormal sequence of proteolytic cleavages of accumulating amyloid precursor protein. Images

Cataldo, A M; Nixon, R A

1990-01-01

221

Resting-State Brain Activity in Adult Males Who Stutter  

Microsoft Academic Search

Although developmental stuttering has been extensively studied with structural and task-based functional magnetic resonance imaging (fMRI), few studies have focused on resting-state brain activity in this disorder. We investigated resting-state brain activity of stuttering subjects by analyzing the amplitude of low-frequency fluctuation (ALFF), region of interest (ROI)-based functional connectivity (FC) and independent component analysis (ICA)-based FC. Forty-four adult males with

Yun Xuan; Chun Meng; Yanhui Yang; Chaozhe Zhu; Liang Wang; Qian Yan; Chunlan Lin; Chunshui Yu

2012-01-01

222

FMRI and brain activation after sport concussion: a tale of two cases.  

PubMed

Sport-related concussions are now recognized as a major public health concern: the number of participants in sport and recreation is growing, possibly playing their games faster, and there is heightened public awareness of injuries to some high-profile athletes. However, many clinicians still rely on subjective symptom reports for the clinical determination of recovery. Relying on subjective symptom reports can be problematic, as it has been shown that some concussed athletes may downplay their symptoms. The use of neuropsychological (NP) testing has enabled clinicians to measure the effects and extent of impairment following concussion more precisely, providing more objective metrics for determining recovery. Nevertheless, there is a remaining concern that brain abnormalities may exist beyond the point at which individuals achieve recovery in self-reported symptoms and cognition measured by NP testing. Our understanding of brain recovery after concussion is important, not only from a neuroscience perspective, but also from the perspective of clinical decision-making for safe return-to-play. A number of advanced neuroimaging tools, including blood oxygen level dependent functional magnetic resonance imaging (fMRI), have independently yielded early information on abnormal brain functioning. In the two cases presented in this article, we report contrasting brain activation patterns and recovery profiles using fMRI. Importantly, fMRI was conducted using adapted versions of the most sensitive computerized NP tests administered in our current clinical practice to determine impairments and recovery after sport-related concussion. One of the cases is consistent with the concept of lagging brain recovery. PMID:24782819

Hutchison, Michael G; Schweizer, Tom A; Tam, Fred; Graham, Simon J; Comper, Paul

2014-01-01

223

fMRI and Brain Activation after Sport Concussion: A Tale of Two Cases  

PubMed Central

Sport-related concussions are now recognized as a major public health concern: the number of participants in sport and recreation is growing, possibly playing their games faster, and there is heightened public awareness of injuries to some high-profile athletes. However, many clinicians still rely on subjective symptom reports for the clinical determination of recovery. Relying on subjective symptom reports can be problematic, as it has been shown that some concussed athletes may downplay their symptoms. The use of neuropsychological (NP) testing has enabled clinicians to measure the effects and extent of impairment following concussion more precisely, providing more objective metrics for determining recovery. Nevertheless, there is a remaining concern that brain abnormalities may exist beyond the point at which individuals achieve recovery in self-reported symptoms and cognition measured by NP testing. Our understanding of brain recovery after concussion is important, not only from a neuroscience perspective, but also from the perspective of clinical decision-making for safe return-to-play. A number of advanced neuroimaging tools, including blood oxygen level dependent functional magnetic resonance imaging (fMRI), have independently yielded early information on abnormal brain functioning. In the two cases presented in this article, we report contrasting brain activation patterns and recovery profiles using fMRI. Importantly, fMRI was conducted using adapted versions of the most sensitive computerized NP tests administered in our current clinical practice to determine impairments and recovery after sport-related concussion. One of the cases is consistent with the concept of lagging brain recovery.

Hutchison, Michael G.; Schweizer, Tom A.; Tam, Fred; Graham, Simon J.; Comper, Paul

2013-01-01

224

Temporal changes in mouse brain fatty acid amide hydrolase activity  

PubMed Central

Fatty acid amide hydrolase (FAAH) activity is known to mediate the tone of endogenous fatty acid amides including the endocannabinoid anandamide (AEA). FAAH is a potential therapeutic target becuase genetic or pharmacological ablation of FAAH promotes analgesia and anxiolytic effects without disrupting motor coordination. Little is known about the endogenous temporal fluctuations of brain FAAH activity. This is the first comprehensive study examining temporal fluctuations in mouse brain FAAH activity. Regional mouse brain homogenates were generated at the midpoint of the light (“noon”) and dark (“midnight”) cycles. While immunoblots revealed no significant change (P>0.05) in regional activity between these two time points, in vitro activity assays detected a subtle 10% reduction (P<0.05) in cerebellar FAAH activity at midnight. A novel ex vivo autoradiography technique permitted the study of eleven different brain regions, many of which cannot be studied using traditional in vitro methods. The cerebellum and the PAG both exhibited significant (P<0.05) reductions in regional FAAH activity in ‘midnight’ brains. These data confirm the need to account for temporal changes in FAAH activity when therapeutically targeting FAAH.

Glaser, Sherrye T.; Kaczocha, Martin

2009-01-01

225

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

226

Brain Distribution of Cediranib Is Limited by Active Efflux at the Blood-Brain Barrier  

PubMed Central

Cediranib is an orally active tyrosine kinase inhibitor that targets the vascular endothelial growth factor receptor family. Because of its potent antiangiogenic and antitumor activities, cediranib has been evaluated for therapy in glioma, a primary brain tumor. This study investigated the influence of two important efflux transporters at the blood-brain barrier, P-glycoprotein (P-gp) and breast cancer resistance protein (Bcrp), on the delivery of cediranib to the central nervous system. In vitro studies indicated that cediranib is a dual substrate for both P-gp and Bcrp. It is noteworthy that in spite of the in vitro data the in vivo mouse disposition studies conclusively showed that P-gp was the dominant transporter restricting the brain distribution of cediranib. The brain-to-plasma partitioning (AUCbrain/AUCplasma, where AUC is area under the curve) and the steady-state brain-to-plasma concentration ratio of cediranib were approximately 20-fold higher in Mdr1a/b(?/?) and Mdr1a/b(?/?)Bcrp1(?/?) mice compared with wild-type and Bcrp1(?/?) mice. Moreover, there was no significant difference in brain distribution of cediranib between wild-type and Bcrp1(?/?) mice and between Mdr1a/b(?/?) and Mdr1a/b(?/?)Bcrp1(?/?) mice. These results show that, unlike other tyrosine kinase inhibitors that are dual substrates for P-gp and Bcrp, Bcrp does not restrict the distribution of cediranib across the blood-brain barrier. We also show that inhibition of P-gp using specific or nonspecific inhibitors resulted in significantly enhanced delivery of cediranib to the brain. Concurrent administration of cediranib with chemical modulators of efflux transporters can be used as a strategy to enhance delivery and thus efficacy of cediranib in the brain. These findings are clinically relevant to the efficacy of cediranib chemotherapy in glioma.

Wang, Tianli; Agarwal, Sagar

2012-01-01

227

Stereotactic MRI in Dyt1 Dystonia: Focal Signal Abnormalities in the Basal Ganglia Do Not Contraindicate Deep Brain Stimulation  

Microsoft Academic Search

Aims: To study stereotactic magnetic resonance imaging (MRI) features of the basal ganglia in DYT1 primary dystonia. Methods: Twenty-five genetically confirmed DYT1 dystonia patients (age range, 8–66 years; mean age, 22 years) underwent brain MRI under general anesthesia at the time of globus pallidus internus (GPi) deep brain stimulation (DBS) surgery. MR images were retrospectively reviewed for signal intensity alterations.

S. Gavarini; N. Vayssière; P. Delort; L. Cif; B. Biolsi; C. Tancu; X. Vasques; S. Plagnol; A. Bonafe; P. Coubes

2008-01-01

228

Ocular abnormalities in Large myd and Large vls mice, spontaneous models for muscle, eye, and brain diseases  

Microsoft Academic Search

Here we demonstrate previously unreported ocular defects in mice homozygous for a new allele of the Large gene, veils, and for Largemyd mice. Clinically, vitreal fibroplasia and retinal vessel tortuosity and fluorescein leakage are observed. These vascular defects may be due to the extreme disorganization of the astrocytic template on which endothelial cells migrate in the retina. Abnormal electroretinograms recorded

Yongsuk Lee; Shuhei Kameya; Gregory A. Cox; Jennifer Hsu; Wanda Hicks; Terry P. Maddatu; Richard S. Smith; Jürgen K. Naggert; Neal S. Peachey; Patsy M. Nishina

2005-01-01

229

Abnormal brain connectivity in first-episode psychosis: A diffusion MRI tractography study of the corpus callosum  

Microsoft Academic Search

A model of disconnectivity involving abnormalities in the cortex and connecting white matter pathways may explain the clinical manifestations of schizophrenia. Recently, diffusion imaging tractography has made it possible to study white matter pathways in detail and we present here a study of patients with first-episode psychosis using this technique. We selected the corpus callosum for this study because there

Gary Price; Mara Cercignani; Geoffrey J. M. Parker; Daniel R. Altmann; Thomas R. E. Barnes; Gareth J. Barker; Eileen M. Joyce; Maria A. Ron

2007-01-01

230

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.

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

2013-01-01

231

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

232

Evidence of lung surfactant abnormality in respiratory failure. Study of bronchoalveolar lavage phospholipids, surface activity, phospholipase activity, and plasma myoinositol.  

PubMed Central

Autopsy findings suggest that lung surfactant is damaged in the adult respiratory distress syndrome. In the present study 225 bronchoalveolar lavage specimens (78 from 36 patients, 1-78 yr old with respiratory failure, 135 from another 128 patients with other respiratory disease, and 12 from healthy controls) were assayed for the lung profile [lecithin/sphingomyelin (L/S) ratio, saturated lecithin, phosphatidylinositol, and phosphatidylglycerol]. Bronchoalveolar lavage fluid was further analyzed for phospholipids and for phosphatidic acid phosphohydrolase, phospholipase A2, and phosphatidylinositol phosphodiesterase activities. A lipid-protein complex was isolated and analyzed for surface activity, and plasma was measured for myoinositol. There were only small differences seen in the recovery of total phospholipid between respiratory failure patients and normal controls. However, in respiratory failure, phospholipids in bronchoalveolar lavage were qualitatively different from those recovered either from normal controls or from patients with other lung disease: the LO/S ratio, phosphatidylglycerol, and disaturated lecithin were low, whereas sphingomyelin and phosphatidylserine were prominent. These abnormalities were present early in respiratory failure and tended to normalize during recovery. Low L/S ratio (less than 2), and low phosphatidylglycerol (1% or less of glycerophospholipids) in bronchoalveolar lavage was always associated with respiratory failure. Abnormal lavage phospholipids were not due to plasma contamination. The phospholipase studies revealed little evidence of increased catabolism of phospholipids. In respiratory failure, the lipid-protein complexes from lung lavage were not surface active, whereas that from healthy controls had surface properties similar to lung surfactant. Phospholipids from patients with respiratory failure were similar to those from respiratory distress syndrome in the newborn. However, the latter condition is characterized by fast recovery of surfactant deficiency and by high plasma myoinositol that suppresses the synthesis of surfactant phosphatidylglycerol and increases phosphatidylinositol (Pediatr. Res. 1981. 15: 720). On the other hand, in adult respiratory distress syndrome, the abnormality in surfactant phospholipids may last for weeks and in most cases is associated with low phosphatidylinositol, low phosphatidylglycerol, and low plasma myoinositol.

Hallman, M; Spragg, R; Harrell, J H; Moser, K M; Gluck, L

1982-01-01

233

Subanesthetic Ketamine Treatment Promotes Abnormal Interactions between Neural Subsystems and Alters the Properties of Functional Brain Networks.  

PubMed

Acute treatment with subanesthetic ketamine, a non-competitive N-methyl-D-aspartic acid (NMDA) receptor antagonist, is widely utilized as a translational model for schizophrenia. However, how acute NMDA receptor blockade impacts on brain functioning at a systems level, to elicit translationally relevant symptomatology and behavioral deficits, has not yet been determined. Here, for the first time, we apply established and recently validated topological measures from network science to brain imaging data gained from ketamine-treated mice to elucidate how acute NMDA receptor blockade impacts on the properties of functional brain networks. We show that the effects of acute ketamine treatment on the global properties of these networks are divergent from those widely reported in schizophrenia. Where acute NMDA receptor blockade promotes hyperconnectivity in functional brain networks, pronounced dysconnectivity is found in schizophrenia. We also show that acute ketamine treatment increases the connectivity and importance of prefrontal and thalamic brain regions in brain networks, a finding also divergent to alterations seen in schizophrenia. In addition, we characterize how ketamine impacts on bipartite functional interactions between neural subsystems. A key feature includes the enhancement of prefrontal cortex (PFC)-neuromodulatory subsystem connectivity in ketamine-treated animals, a finding consistent with the known effects of ketamine on PFC neurotransmitter levels. Overall, our data suggest that, at a systems level, acute ketamine-induced alterations in brain network connectivity do not parallel those seen in chronic schizophrenia. Hence, the mechanisms through which acute ketamine treatment induces translationally relevant symptomatology may differ from those in chronic schizophrenia. Future effort should therefore be dedicated to resolve the conflicting observations between this putative translational model and schizophrenia. PMID:24492765

Dawson, Neil; McDonald, Martin; Higham, Desmond J; Morris, Brian J; Pratt, Judith A

2014-06-01

234

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.

Zumbrennen-Bullough, Kimberly B.; Becker, Lore; Garrett, Lillian; Holter, 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 Hrabe; Romney, Steven J.; Leibold, Elizabeth A.

2014-01-01

235

Brain modularity controls the critical behavior of spontaneous activity.  

PubMed

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. PMID:24621482

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

2014-01-01

236

Brain modularity controls the critical behavior of spontaneous activity  

PubMed Central

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.

2014-01-01

237

[Proliferative activity of glial neoplasms of the brain].  

PubMed

The aim of the study including 89 brain gliomas was to determine their proliferative activity assayed with immunohistochemical methods (PCNA and Ki-67) and with the method of AgNORs, as well as to evaluate the correlation between the proliferative activity and features of histological malignancy. The study reveals that the estimation of PCNA, Ki-67 and AgNORs are effective methods for the determination of the proliferative activity of brain gliomas. Statistically significant differences were noted in the proliferative PCNA, Ki-67 and AgNORs between groups of gliomas with lower and higher malignancy, which indicated a distinct correlation between histological malignancy of the tumours and their proliferative activity. High values of PCNA and Ki-67 (> 40%) and AgNORs (> 15) were found to considerably deteriorate prognosis in brain gliomas. PMID:10399728

Zimnoch, L; Kozielec, Z; Lewko, J; Cylwik, B; Mariak, Z

1999-01-01

238

Brain activation during smooth-pursuit eye movements.  

PubMed

A potential application of studying eye movements with functional MRI (fMRI) is to examine patient populations with known eye movement dysfunction, but the reliability with which normal subjects demonstrate activity in specific brain regions has not been established. To date, fMRI studies of smooth-pursuit eye movements have used relatively small numbers of subjects and have been restricted to fixed-effects analyses. We extend these studies to whole brain imaging at 1.5 T, properly accounting for intersubject variation using random effects analysis. Smooth-pursuit eye movements elicited activation consistently in dorsal cortical eye fields and cerebellum. Subcortical activation was greatly attenuated, but not eliminated, with the random-effects second-level analysis. In addition, session-dependent changes in activation were greater in some regions than others and may indicate areas of brain, such as the supplementary eye fields, that are sensitive to attentional modulation of eye movements. PMID:12414271

Tanabe, Jody; Tregellas, Jason; Miller, David; Ross, Randal G; Freedman, Robert

2002-11-01

239

PEX13 deficiency in mouse brain as a model of Zellweger syndrome: abnormal cerebellum formation, reactive gliosis and oxidative stress  

PubMed Central

SUMMARY Delayed cerebellar development is a hallmark of Zellweger syndrome (ZS), a severe neonatal neurodegenerative disorder. ZS is caused by mutations in PEX genes, such as PEX13, which encodes a protein required for import of proteins into the peroxisome. The molecular basis of ZS pathogenesis is not known. We have created a conditional mouse mutant with brain-restricted deficiency of PEX13 that exhibits cerebellar morphological defects. PEX13 brain mutants survive into the postnatal period, with the majority dying by 35 days, and with survival inversely related to litter size and weaning body weight. The impact on peroxisomal metabolism in the mutant brain is mixed: plasmalogen content is reduced, but very-long-chain fatty acids are normal. PEX13 brain mutants exhibit defects in reflex and motor development that correlate with impaired cerebellar fissure and cortical layer formation, granule cell migration and Purkinje cell layer development. Astrogliosis and microgliosis are prominent features of the mutant cerebellum. At the molecular level, cultured cerebellar neurons from E19 PEX13-null mice exhibit elevated levels of reactive oxygen species and mitochondrial superoxide dismutase-2 (MnSOD), and show enhanced apoptosis together with mitochondrial dysfunction. PEX13 brain mutants show increased levels of MnSOD in cerebellum. Our findings suggest that PEX13 deficiency leads to mitochondria-mediated oxidative stress, neuronal cell death and impairment of cerebellar development. Thus, PEX13-deficient mice provide a valuable animal model for investigating the molecular basis and treatment of ZS cerebellar pathology.

Muller, C. Catharina; Nguyen, Tam H.; Ahlemeyer, Barbara; Meshram, Mallika; Santrampurwala, Nishreen; Cao, Siyu; Sharp, Peter; Fietz, Pamela B.; Baumgart-Vogt, Eveline; Crane, Denis I.

2011-01-01

240

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.

2013-01-01

241

Brain activation patterns associated with cue reactivity and craving in abstinent problem gamblers, heavy smokers and healthy controls: an fMRI study  

Microsoft Academic Search

Abnormal cue reactivity is a central characteristic of addiction, associated with increased activity in motivation, attention and memory related brain circuits. In this neuroimaging study, cue reactivity in problem gamblers (PRG) was compared with cue reactivity in heavy smokers (HSM) and healthy controls (HC). A functional magnetic resonance imaging event-related cue reactivity paradigm, consisting of gambling, smoking-related and neutral pictures,

A. E. Goudriaan; Ruiter de M. B; Brink van den W; J. Oosterlaan; D. J. Veltman

2010-01-01

242

Measuring Emotion in Advertising Research: Prefrontal Brain Activity  

Microsoft Academic Search

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

Richard Silberstein; Geoffrey Nield

2012-01-01

243

Brain acetycholinesterase activity in botulism-intoxicated mallards  

USGS Publications Warehouse

Brain acetylcholinesterase (AChE) activity in captive-reared mallards (Anas platyrhynchos) that died of botulism was compared with euthanized controls. AChE levels for both groups were within the range reported for normal mallards, and there was no significant difference in mean AChE activity between birds that ingested botulism toxin and died and those that did not.

Rocke, T. E.; Samuel, M. D.

1991-01-01

244

The duplication 17p13.3 phenotype: analysis of 21 families delineates developmental, behavioral and brain abnormalities, and rare variant phenotypes.  

PubMed

Chromosome 17p13.3 is a gene rich region that when deleted is associated with the well-known Miller-Dieker syndrome. A recently described duplication syndrome involving this region has been associated with intellectual impairment, autism and occasional brain MRI abnormalities. We report 34 additional patients from 21 families to further delineate the clinical, neurological, behavioral, and brain imaging findings. We found a highly diverse phenotype with inter- and intrafamilial variability, especially in cognitive development. The most specific phenotype occurred in individuals with large duplications that include both the YWHAE and LIS1 genes. These patients had a relatively distinct facial phenotype and frequent structural brain abnormalities involving the corpus callosum, cerebellar vermis, and cranial base. Autism spectrum disorders were seen in a third of duplication probands, most commonly in those with duplications of YWHAE and flanking genes such as CRK. The typical neurobehavioral phenotype was usually seen in those with the larger duplications. We did not confirm the association of early overgrowth with involvement of YWHAE and CRK, or growth failure with duplications of LIS1. Older patients were often overweight. Three variant phenotypes included cleft lip/palate (CLP), split hand/foot with long bone deficiency (SHFLD), and a connective tissue phenotype resembling Marfan syndrome. The duplications in patients with clefts appear to disrupt ABR, while the SHFLD phenotype was associated with duplication of BHLHA9 as noted in two recent reports. The connective tissue phenotype did not have a convincing critical region. Our experience with this large cohort expands knowledge of this diverse duplication syndrome. PMID:23813913

Curry, Cynthia J; Rosenfeld, Jill A; Grant, Erica; Gripp, Karen W; Anderson, Carol; Aylsworth, Arthur S; Saad, Taha Ben; Chizhikov, Victor V; Dybose, Giedre; Fagerberg, Christina; Falco, Michelle; Fels, Christina; Fichera, Marco; Graakjaer, Jesper; Greco, Donatella; Hair, Jennifer; Hopkins, Elizabeth; Huggins, Marlene; Ladda, Roger; Li, Chumei; Moeschler, John; Nowaczyk, Malgorzata J M; Ozmore, Jillian R; Reitano, Santina; Romano, Corrado; Roos, Laura; Schnur, Rhonda E; Sell, Susan; Suwannarat, Pim; Svaneby, Dea; Szybowska, Marta; Tarnopolsky, Mark; Tervo, Raymond; Tsai, Anne Chun-Hui; Tucker, Megan; Vallee, Stephanie; Wheeler, Ferrin C; Zand, Dina J; Barkovich, A James; Aradhya, Swaroop; Shaffer, Lisa G; Dobyns, William B

2013-08-01

245

Mapping Functional Brain Activation Using [14C]-Iodoantipyrine in Male Serotonin Transporter Knockout Mice  

PubMed Central

Background Serotonin transporter knockout mice have been a powerful tool in understanding the role played by the serotonin transporter in modulating physiological function and behavior. However, little work has examined brain function in this mouse model. We tested the hypothesis that male knockout mice show exaggerated limbic activation during exposure to an emotional stressor, similar to human subjects with genetically reduced transcription of the serotonin transporter. Methodology/Principal Findings Functional brain mapping using [14C]-iodoantipyrine was performed during recall of a fear conditioned tone. Regional cerebral blood flow was analyzed by statistical parametric mapping from autoradiographs of the three-dimensionally reconstructed brains. During recall, knockout mice compared to wild-type mice showed increased freezing, increased regional cerebral blood flow of the amygdala, insula, and barrel field somatosensory cortex, decreased regional cerebral blood flow of the ventral hippocampus, and conditioning-dependent alterations in regional cerebral blood flow in the medial prefrontal cortex (prelimbic, infralimbic, and cingulate). Anxiety tests relying on sensorimotor exploration showed a small (open field) or paradoxical effect (marble burying) of loss of the serotonin transporter on anxiety behavior, which may reflect known abnormalities in the knockout animal's sensory system. Experiments evaluating whisker function showed that knockout mice displayed impaired whisker sensation in the spontaneous gap crossing task and appetitive gap cross training. Conclusions This study is the first to demonstrate altered functional activation in the serotonin transporter knockout mice of critical nodes of the fear conditioning circuit. Alterations in whisker sensation and functional activation of barrel field somatosensory cortex extend earlier reports of barrel field abnormalities, which may confound behavioral measures relying on sensorimotor exploration.

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

2011-01-01

246

Lateralization of brain activation in fluent and non-fluent preschool children: a magnetoencephalographic study of picture-naming.  

PubMed

The neural causes of stuttering remain unknown. One explanation comes from neuroimaging studies that have reported abnormal lateralization of activation in the brains of people who stutter. However, these findings are generally based on data from adults with a long history of stuttering, raising the possibility that the observed lateralization anomalies are compensatory rather than causal. The current study investigated lateralization of brain activity in language-related regions of interest in young children soon after the onset of stuttering. We tested 24 preschool-aged children, half of whom had a positive diagnosis of stuttering. All children participated in a picture-naming experiment whilst their brain activity was recorded by magnetoencephalography. Source analysis performed during an epoch prior to speech onset was used to assess lateralized activation in three regions of interest. Activation was significantly lateralized to the left hemisphere in both groups and not different between groups. This study shows for the first time that significant speech preparatory brain activation can be identified in young children during picture-naming and supports the contention that, in stutterers, aberrant lateralization of brain function may be the result of neuroplastic adaptation that occurs as the condition becomes chronic. PMID:24904388

Sowman, Paul F; Crain, Stephen; Harrison, Elisabeth; Johnson, Blake W

2014-01-01

247

Lateralization of Brain Activation in Fluent and Non-Fluent Preschool Children: A Magnetoencephalographic Study of Picture-Naming  

PubMed Central

The neural causes of stuttering remain unknown. One explanation comes from neuroimaging studies that have reported abnormal lateralization of activation in the brains of people who stutter. However, these findings are generally based on data from adults with a long history of stuttering, raising the possibility that the observed lateralization anomalies are compensatory rather than causal. The current study investigated lateralization of brain activity in language-related regions of interest in young children soon after the onset of stuttering. We tested 24 preschool-aged children, half of whom had a positive diagnosis of stuttering. All children participated in a picture-naming experiment whilst their brain activity was recorded by magnetoencephalography. Source analysis performed during an epoch prior to speech onset was used to assess lateralized activation in three regions of interest. Activation was significantly lateralized to the left hemisphere in both groups and not different between groups. This study shows for the first time that significant speech preparatory brain activation can be identified in young children during picture-naming and supports the contention that, in stutterers, aberrant lateralization of brain function may be the result of neuroplastic adaptation that occurs as the condition becomes chronic.

Sowman, Paul F.; Crain, Stephen; Harrison, Elisabeth; Johnson, Blake W.

2014-01-01

248

High dose CART peptide induces abnormal EEG activity and behavioral seizures.  

PubMed

Cocaine- and amphetamine-regulated transcript (CART) peptides are neurotransmitters found throughout the nervous system and in the periphery. CART has an important role in the regulation of food intake, anxiety, endocrine function, and in mesolimbic-mediated reward and reinforcement. This short report casts light upon previous descriptions of presumed behavioral seizure and tremor activity following administration of CART into the central nervous system. By employing electroencephalographic (EEG) recordings, we document the state of cerebrocortical activity. We find that intracerebroventricular (icv) administration of 5 microg of CART 55-102 readily produces an abnormal EEG characterized initially by high amplitude hypersynchronous alpha in the 8-10 Hz range during behavioral wakefulness as manifest in both cortical and hippocampal theta EEG channels. This reliably progressed in three of three animals tested to unequivocal epileptiform activity accompanied by tremors and assumption of a rigid, tonic body posture. The neural substrates underlying this finding are unclear. This novel description of the epileptogenic quality of CART should lend caution to interpretations of the behaviors attributed to CART in other experimental paradigms. PMID:18178249

Keating, Glenda L; Kuhar, Michael J; Rye, David B

2008-04-01

249

Resting brain metabolic activity in a 4 tesla magnetic field.  

PubMed

MRI is a major tool for mapping brain function; thus it is important to assess potential effects on brain neuronal activity attributable to the requisite static magnetic field. This study used positron emission tomography (PET) and (18)F-deoxyglucose ((18)FDG) to measure brain glucose metabolism (a measure of brain function) in 12 subjects while their heads were in a 4 T MRI field during the (18)FDG uptake period. The results were compared with those obtained when the subjects were in the earth's field (PET scanner), and when they were in a simulated MRI environment in the PET instrument that imitated the restricted visual field of the MRI experiment. Whole-brain metabolism, as well as metabolism in occipital cortex and posterior cingulate gyrus, was lower in the real (4 T) and simulated (0 T) MRI environments compared with the PET. This suggests that the metabolic differences are due mainly to the visual field differences characteristic of the MRI and PET instruments. We conclude that a static magnetic field of 4 T does not in itself affect this fairly sensitive measure of brain activity. PMID:11064404

Volkow, N D; Wang, G J; Fowler, J S; Rooney, W D; Felder, C A; Lee, J H; Franceschi, D; Maynard, L; Schlyer, D J; Pan, J W; Gatley, S J; Springer Jr, C S

2000-11-01

250

Consumption of Fermented Milk Product With Probiotic Modulates Brain Activity  

PubMed Central

BACKGROUND & AIMS Changes in gut microbiota have been reported to alter signaling mechanisms, emotional behavior, and visceral nociceptive reflexes in rodents. However, alteration of the intestinal microbiota with antibiotics or probiotics has not been shown to produce these changes in humans. We investigated whether consumption of a fermented milk product with probiotic (FMPP) for 4 weeks by healthy women altered brain intrinsic connectivity or responses to emotional attention tasks. METHODS Healthy women with no gastrointestinal or psychiatric symptoms were randomly assigned to groups given FMPP (n = 12), a nonfermented milk product (n = 11, controls), or no intervention (n = 13) twice daily for 4 weeks. The FMPP contained Bifidobacterium animalis subsp Lactis, Streptococcus thermophiles, Lactobacillus bulgaricus, and Lactococcus lactis subsp Lactis. Participants underwent functional magnetic resonance imaging before and after the intervention to measure brain response to an emotional faces attention task and resting brain activity. Multivariate and region of interest analyses were performed. RESULTS FMPP intake was associated with reduced task-related response of a distributed functional network (49% cross-block covariance; P = .004) containing affective, viscerosensory, and somatosensory cortices. Alterations in intrinsic activity of resting brain indicated that ingestion of FMPP was associated with changes in midbrain connectivity, which could explain the observed differences in activity during the task. CONCLUSIONS Four-week intake of an FMPP by healthy women affected activity of brain regions that control central processing of emotion and sensation.

TILLISCH, KIRSTEN; LABUS, JENNIFER; KILPATRICK, LISA; JIANG, ZHIGUO; STAINS, JEAN; EBRAT, BAHAR; GUYONNET, DENIS; LEGRAIN-RASPAUD, SOPHIE; TROTIN, BEATRICE; NALIBOFF, BRUCE; MAYER, EMERAN A.

2013-01-01

251

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

252

Central motor conduction in multiple sclerosis: evaluation of abnormalities revealed by transcutaneous magnetic stimulation of the brain  

Microsoft Academic Search

Magnetic stimulation of the brain and spinal column was used to assess conduction in the descending central motor pathways controlling arm and leg muscles of 20 patients with multiple sclerosis, and 10 normal subjects. The multiple sclerosis patients had relapsing and remitting disease but all were ambulant and in stable clinical remission. Increased central motor conduction times (CMCTs), up to

D A Ingram; A J Thompson; M Swash

1988-01-01

253

Brain activity in predominantly-inattentive subtype attention-deficit/hyperactivity disorder during an auditory oddball attention task.  

PubMed

Previous functional neuroimaging studies have found brain activity abnormalities in attention-deficit/hyperactivity disorder (ADHD) on numerous cognitive tasks. However, little is known about brain dysfunction unique to the predominantly-inattentive subtype of ADHD (ADHD-I), despite debate as to whether DSM-IV-defined ADHD subtypes differ in etiology. This study compared brain activity of 18 ADHD-I adolescents (ages 12-18) and 20 non-psychiatric age-matched control participants on a functional magnetic resonance image (fMRI) auditory oddball attention task. ADHD-I participants had significant activation deficits to infrequent target stimuli in bilateral superior temporal gyri, bilateral insula, several midline cingulate/medial frontal gyrus regions, right posterior parietal cortex, thalamus, cerebellum, and brainstem. To novel stimuli, ADHD-I participants had reduced activation in bilateral lateral temporal lobe structures. There were no brain regions where ADHD-I participants had greater hemodynamic activity to targets or novels than controls. Brain activity deficits in ADHD-I participants were found in several regions important to attentional orienting and working memory-related cognitive processes involved in target identification. These results differ from those in previously studied adolescents with combined-subtype ADHD, who had a lesser magnitude of activation abnormalities in frontoparietal regions and relatively more discrete regional deficits to novel stimuli. The divergent findings suggest different etiological factors might underlie attention deficits in different DSM-IV-defined ADHD subtypes, and they have important implications for the DSM-V reconceptualization of subtypes as varying clinical presentations of the same core disorder. PMID:24953999

Orinstein, Alyssa J; Stevens, Michael C

2014-08-30

254

Methamphetamine Causes Microglial Activation in the Brains of Human Abusers  

PubMed Central

Methamphetamine is a popular addictive drug whose use is associated with multiple neuropsychiatric adverse events and toxic to the dopaminergic and serotonergic systems of the brain. Methamphetamine-induced neuropathology is associated with increased expression of microglial cells that are thought to participate in either pro-toxic or protective mechanisms in the brain. Although reactive microgliosis has been observed in animal models of methamphetamine neurotoxicity, no study has reported on the status of microglial activation in human methamphetamine abusers. The present study reports on 12 abstinent methamphetamine abusers and 12 age-, gender-, education-matched control subjects who underwent positron emission tomography using a radiotracer for activated microglia, [11C](R)-(1-[2-chlorophenyl]-N-methyl-N-[1-methylpropyl]-3-isoquinoline carboxamide) ([11C](R)-PK11195). Compartment analysis was used to estimate quantitative levels of binding potentials of [11C](R)-PK11195 in brain regions with dopaminergic and/or serotonergic innervation. The mean levels of [11C](R)-PK11195 binding were higher in methamphetamine abusers than those in control subjects in all brain regions (> 250% higher, p < 0.01 for all). In addition, the binding levels in the midbrain, striatum, thalamus, and orbitofrontal and insular cortices (p < 0.05) correlated inversely with the duration of methamphetamine abstinence. These results suggest that chronic self-administration of methamphetamine can cause reactive microgliosis in the brains of human methamphetamine abusers, a level of activation that appears to subside over longer periods of abstinence.

Sekine, Yoshimoto; Ouchi, Yasuomi; Sugihara, Genichi; Takei, Nori; Yoshikawa, Etsuji; Nakamura, Kazuhiko; Iwata, Yasuhide; Tsuchiya, Kenji J.; Suda, Shiro; Suzuki, Katsuaki; Kawai, Masayoshi; Takebayashi, Kiyokazu; Yamamoto, Shigeyuki; Matsuzaki, Hideo; Ueki, Takatoshi; Mori, Norio; Gold, Mark S.; Cadet, Jean L.

2008-01-01

255

Proline Affects Brain Function in 22q11DS Children with the Low Activity COMT158 Allele  

PubMed Central

The association between the 22q11.2 deletion syndrome (22q11DS) and psychiatric disorders, particularly psychosis, suggests a causal relationship between 22q11DS genes and abnormal brain function. The genes catechol-O-methyl-transferase (COMT) and proline dehydrogenase both reside within the commonly deleted region of 22q11.2. COMT activity and proline levels may therefore be altered in 22q11DS individuals. Associations of both COMT158 genotype and elevated serum proline levels with abnormal brain function have been reported. Fifty-six 22q11DS children and 75 healthy controls were assessed on physiological measures of brain function, including prepulse inhibition (PPI) of startle, P50 auditory sensory gating and smooth pursuit eye movements (SPEM). COMT158 genotype and plasma proline levels were determined in the 22q11DS children. We hypothesized an interaction between the COMT158 genotype and proline, predicting the strongest negative effect of high proline on brain function to occur in 22q11DS children who are carriers of the COMTmet allele. Of the three physiological measures, only SPEM and PPI were abnormal in the patient sample. With regard to the SPEM performance, there was a significant interaction between the COMT158 genotype and proline level with significantly decreased SPEM performance in children with high plasma proline levels and the low activity COMTmet allele. A similar interaction effect was not observed with regard to PPI. These findings are consistent with a model in which elevated proline negatively affects brain function by an increase in dopamine in the prefrontal cortex. 22q11DS patients with low dopamine catabolic capacity are therefore especially vulnerable to this functional disruption.

Vorstman, Jacob AS; Turetsky, Bruce I; Sijmens-Morcus, Monique EJ; de Sain, Monique G; Dorland, Bert; Sprong, Mirjam; Rappaport, Eric F; Beemer, Frits A; Emanuel, Beverly S; Kahn, Rene S; van Engeland, Herman; Kemner, Chantal

2010-01-01

256

On a Mathematical Model of Brain Activities  

NASA Astrophysics Data System (ADS)

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 [1]. 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 [2, 3]. 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.; Fichtner, L.; Freudenberg, W.; Ohya, M.

2007-12-01

257

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

258

Dach1 Mutant Mice Bear No Gross Abnormalities in Eye, Limb, and Brain Development and Exhibit Postnatal Lethality  

Microsoft Academic Search

Drosophila dachshund is necessary and sufficient for compound eye development and is required for normal leg and brain development. A mouse homologue of dachshund, Dach1, is expressed in the developing retina and limbs, suggesting functional conservation of this gene. We have generated a loss-of-function mutation in Dach1 that results in the abrogation of the wild-type RNA and protein expression pattern

RICHARD J. DAVIS; WEIPING SHEN; YAKOV I. SANDLER; MEHRAN AMOUI; PATRICIA PURCELL; RICHARD MAAS; CHING-NAN OU; HANNES VOGEL; ARTHUR L. BEAUDET; GRAEME MARDON

2001-01-01

259

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

260

Cdk5 activity in the brain - multiple paths of regulation.  

PubMed

Cyclin dependent kinase-5 (Cdk5), a family member of the cyclin-dependent kinases, plays a pivotal role in the central nervous system. During embryogenesis, Cdk5 is indispensable for brain development and, in the adult brain, it is essential for numerous neuronal processes, including higher cognitive functions such as learning and memory formation. However, Cdk5 activity becomes deregulated in several neurological disorders, such as Alzheimer's disease, Parkinson's disease and Huntington's disease, which leads to neurotoxicity. Therefore, precise control over Cdk5 activity is essential for its physiological functions. This Commentary covers the various mechanisms of Cdk5 regulation, including several recently identified protein activators and inhibitors of Cdk5 that control its activity in normal and diseased brains. We also discuss the autoregulatory activity of Cdk5 and its regulation at the transcriptional, post-transcriptional and post-translational levels. We finally highlight physiological and pathological roles of Cdk5 in the brain. Specific modulation of these protein regulators is expected to provide alternative strategies for the development of effective therapeutic interventions that are triggered by deregulation of Cdk5. PMID:24879856

Shah, Kavita; Lahiri, Debomoy K

2014-06-01

261

Active tactile exploration enabled by a brain-machine-brain interface  

PubMed Central

Brain-machine interfaces (BMIs)1,2 use neuronal activity recorded from the brain to establish direct communication with external actuators, such as prosthetic arms. While BMIs aim to restore the normal sensorimotor functions of the limbs, so far they have lacked tactile sensation. Here we demonstrate the operation of a brain-machine-brain interface (BMBI) that both controls the exploratory reaching movements of an actuator and enables the signalling of artificial tactile feedback through intracortical microstimulation (ICMS) of the primary somatosensory cortex (S1). Monkeys performed an active-exploration task in which an actuator (a computer cursor or a virtual-reality hand) was moved using a BMBI that derived motor commands from neuronal ensemble activity recorded in primary motor cortex (M1). ICMS feedback occurred whenever the actuator touched virtual objects. Temporal patterns of ICMS encoded the artificial tactile properties of each object. Neuronal recordings and ICMS epochs were temporally multiplexed to avoid interference. Two monkeys operated this BMBI to search and discriminate one out of three visually undistinguishable objects, using the virtual hand to identify the unique artificial texture (AT) associated with each. These results suggest that clinical motor neuroprostheses might benefit from the addition of ICMS feedback to generate artificial somatic perceptions associated with mechanical, robotic, or even virtual prostheses.

O'Doherty, Joseph E.; Lebedev, Mikhail A.; Ifft, Peter J.; Zhuang, Katie Z.; Shokur, Solaiman; Bleuler, Hannes; Nicolelis, Miguel A. L.

2011-01-01

262

Use of brain electrical activity for the identification of hematomas in mild traumatic brain injury.  

PubMed

This study investigates the potential clinical utility in the emergency department (ED) of an index of brain electrical activity to identify intracranial hematomas. The relationship between this index and depth, size, and type of hematoma was explored. Ten minutes of brain electrical activity was recorded from a limited montage in 38 adult patients with traumatic hematomas (CT scan positive) and 38 mild head injured controls (CT scan negative) in the ED. The volume of blood and distance from recording electrodes were measured by blinded independent experts. Brain electrical activity data were submitted to a classification algorithm independently developed traumatic brain injury (TBI) index to identify the probability of a CT+traumatic event. There was no significant relationship between the TBI-Index and type of hematoma, or distance of the bleed from recording sites. A significant correlation was found between TBI-Index and blood volume. The sensitivity to hematomas was 100%, positive predictive value was 74.5%, and positive likelihood ratio was 2.92. The TBI-Index, derived from brain electrical activity, demonstrates high accuracy for identification of traumatic hematomas. Further, this was not influenced by distance of the bleed from the recording electrodes, blood volume, or type of hematoma. Distance and volume limitations noted with other methods, (such as that based on near-infrared spectroscopy) were not found, thus suggesting the TBI-Index to be a potentially important adjunct to acute assessment of head injury. Because of the life-threatening risk of undetected hematomas (false negatives), specificity was permitted to be lower, 66%, in exchange for extremely high sensitivity. PMID:24040943

Hanley, Daniel F; Chabot, Robert; Mould, W Andrew; Morgan, Timothy; Naunheim, Rosanne; Sheth, Kevin N; Chiang, William; Prichep, Leslie S

2013-12-15

263

Altered baseline brain activity in children with bipolar disorder during mania state: a resting-state study  

PubMed Central

Background Previous functional magnetic resonance imaging (fMRI) studies have shown abnormal functional connectivity in regions involved in emotion processing and regulation in pediatric bipolar disorder (PBD). Recent studies indicate, however, that task-dependent neural changes only represent a small fraction of the brain’s total activity. How the brain allocates the majority of its resources at resting state is still unknown. We used the amplitude of low-frequency fluctuation (ALFF) method of fMRI to explore the spontaneous neuronal activity in resting state in PBD patients. Methods Eighteen PBD patients during the mania phase and 18 sex-, age- and education-matched healthy subjects were enrolled in this study and all patients underwent fMRI scanning. The ALFF method was used to compare the resting-state spontaneous neuronal activity between groups. Correlation analysis was performed between the ALFF values and Young Mania Rating Scale scores. Results Compared with healthy controls, PBD patients presented increased ALFF in bilateral caudate and left pallidum as well as decreased ALFF in left precuneus, left superior parietal lobule, and bilateral inferior occipital gyrus. Additionally, ALFF values in left pallidum were positively correlated with Young Mania Rating Scale score in PBD. Conclusion The abnormal resting-state neuronal activities of the basal ganglia, parietal cortex, and occipital cortex may play an important role in the pathophysiology in PBD patients.

Lu, Dali; Jiao, Qing; Zhong, Yuan; Gao, Weijia; Xiao, Qian; Liu, Xiaoqun; Lin, Xiaoling; Cheng, Wentao; Luo, Lanzhu; Xu, Chuanjian; Lu, Guangming; Su, Linyan

2014-01-01

264

Patterns of brain activity in patients with epilepsy and depression  

Microsoft Academic Search

Depression is a recognized feature of epilepsy. This study tested the hypothesis that depression arising in patients with epilepsy would be associated with decreased activity in brain regions previously demonstrated to be hypoperfused both in primary depression and in depression secondary to movement disorders. Two groups of patients with temporal lobe epilepsy were studied, one of which also met DSM

H. A. Ring; P. D. Acton; D. Scull; D. C. Costa; S. Gacinovik; M. R. Trimble

1999-01-01

265

Perceived causality influences brain activity evoked by biological motion  

Microsoft Academic Search

Using functional magnetic resonance imaging (fMRI), we investigated brain activity in an observer who watched the hand and arm motions of an individual when that individual was, or was not, the cause of the motion. Subjects viewed a realistic animated 3D character who sat at a table containing four pistons. On Intended Motion trials, the character raised his hand and

James P. Morris; Kevin A. Pelphrey; Gregory McCarthy

2008-01-01

266

Global Optimization in the Localization of Brain Activity.  

National Technical Information Service (NTIS)

The locations of active brain areas can be estimated from the magnetic field produced by the neural current sources. In many cases, the actual current dipoles with time-varying amplitudes. This work studies global optimization methods that find the minimu...

K. Uutela M. Haemaelaeinen R. Salmelin

1996-01-01

267

Brain Activity Related to the Perception of Illusory Contours  

Microsoft Academic Search

We have addressed the question of whether the brain's capacity to resolve an ambiguous retinal image depends upon the activity of early visual areas or whether it involves the investment of the received image with higher order cognitive hypotheses. To resolve the issue, we have used the technique of positron emission tomography to detect increases in regional cerebral blood flow

D. H. ffytche; S. Zeki

1996-01-01

268

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

269

Head Reconstruction and Localization of Brain Activity Using Bayesian Evidence.  

National Technical Information Service (NTIS)

This study is devoted to a detection of evoked potentials in a brain activity with aim to map these potentials onto a scalp. in this case, there is necessary to focus recorded scalp potentials, which are blurred due to scalp attenuation and, moreover mask...

J. Kralik R. Cmejla P. Sovka A. Stancak

2001-01-01

270

Abnormal Tc-99m-MDP/GA-67 scan patterns in association with active chronic osteomyelitis  

SciTech Connect

In this study the authors reviewed data from 136 patients (pts) in order to refine the interpretive criteria used to diagnose active osteomyelitis (AOM) in patients with previous bone disease (e.g., old osteomyelitis, fractures, orthopedic devices excluding prostheses). They evaluated bone (Tc-99mMDP) and gallium 67 studies and obtained followup in all pts. AOM was diagnosed by surgery or biopsy and culture in 49 pts and was excluded by the same criteria in 16 pts. An additional 71 pts had the diagnosis excluded by followup clinical criteria. Five patterns were found. T1: abnormal Tc-99m-MDP, normal Ga-67. T2: diffuse increased uptake of both radiopharmaceuticals with Tc-99m-MDP greater than Ga-67. T3: different geographic distribution, but similar intensities of uptake of both. T4: very similar uptake and distribution of both. T5: Ga-67 exceeded Tc-99m-MDP. The authors conclude that T5 is diagnostic of AOM, T3 and T4 raise the probability of AOM than before scanning, T1 and T2 decrease it.

Tumeh, S.S.; Aliabadi, P.; Weissman, B.; McNeil, B.J.

1985-05-01

271

Regional Brain Structural Abnormality in Meal-Related Functional Dyspepsia Patients: A Voxel-Based Morphometry Study  

PubMed Central

Background and Aims Brain dysfunction in functional dyspepsia (FD) has been identified by multiple neuroimaging studies. This study aims to investigate the regional gray matter density (GMD) changes in meal-related FD patients and their correlations with clinical variables, and to explore the possible influence of the emotional state on FD patients’s brain structures. Methods Fifty meal-related FD patients and forty healthy subjects (HS) were included and underwent a structural magnetic resonance imaging scan. Voxel-based morphometry analysis was employed to identify the cerebral structure alterations in meal-related FD patients. Regional GMD changes' correlations with the symptoms and their durations, respectively, have been analyzed. Results Compared to the HS, the meal-related FD patients showed a decreased GMD in the bilateral precentral gyrus, medial prefrontal cortex (MPFC), anterior cingulate cortex (ACC) and midcingulate cortex (MCC), left orbitofrontal cortex (OFC) and right insula (p<0.05, FWE Corrected, Cluster size>50). After controlling for anxiety and depression, the meal-related FD patients showed a decreased GMD in the bilateral middle frontal gyrus, left MCC, right precentral gyrus and insula (p<0.05, FWE Corrected, Cluster size>50). Before controlling psychological factors, the GMD decreases in the ACC were negatively associated with the symptom scores of the Nepean Dyspepsia Index (NDI) (r?=??0.354, p?=?0.048, Bonferroni correction) and the duration of FD (r?=??0.398, p?=?0.02, Bonferroni correction) respectively. Conclusions The regional GMD of meal-related FD patients, especially in the regions of the homeostatic afferent processing network significantly differed from that of the HS, and the psychological factors might be one of the essential factors significantly affecting the regional brain structure of meal-related FD patients.

Yang, Yue; Zhang, Danhua; Liu, Jixin; Zhou, Guangyu; Sun, Jinbo; Lu, Shengfeng; Tang, Yong; Chen, Yuan; Lan, Lei; Yu, Shuguang; Li, Ying; Gao, Xin; Gong, Qiyong; Tian, Jie; Liang, Fanrong

2013-01-01

272

Brain Abnormalities and Glioma-Like Lesions in Mice Overexpressing the Long Isoform of PDGF-A in Astrocytic Cells  

PubMed Central

Background Deregulation of platelet-derived growth factor (PDGF) signaling is a hallmark of malignant glioma. Two alternatively spliced PDGF-A mRNAs have been described, corresponding to a long (L) and a short (S) isoform of PDGF-A. In contrast to PDGF-A(S), the PDGF-A(L) isoform has a lysine and arginine rich carboxy-terminal extension that acts as an extracellular matrix retention motif. However, the exact role of PDGF-A(L) and how it functionally differs from the shorter isoform is not well understood. Methodology/Principal Findings We overexpressed PDGF-A(L) as a transgene under control of the glial fibrillary acidic protein (GFAP) promoter in the mouse brain. This directs expression of the transgene to astrocytic cells and GFAP expressing neural stem cells throughout the developing and adult central nervous system. Transgenic mice exhibited a phenotype with enlarged skull at approximately 6-16 weeks of age and they died between 1.5 months and 2 years of age. We detected an increased number of undifferentiated cells in all areas of transgene expression, such as in the subependymal zone around the lateral ventricle and in the cerebellar medulla. The cells stained positive for Pdgfr-?, Olig2 and NG2 but this population did only partially overlap with cells positive for Gfap and the transgene reporter. Interestingly, a few mice presented with overt neoplastic glioma-like lesions composed of both Olig2 and Gfap positive cell populations and with microvascular proliferation, in a wild-type p53 background. Conclusions Our findings show that PDGF-A(L) can induce accumulation of immature cells in the mouse brain. The strong expression of NG2, Pdgfr-? and Olig2 in PDGF-A(L) brains suggests that a fraction of these cells are oligodendrocyte progenitors. In addition, accumulation of fluid in the subarachnoid space and skull enlargement indicate that an increased intracranial pressure contributed to the observed lethality.

Nazarenko, Inga; Hedren, Anna; Sjodin, Hanna; Orrego, Abiel; Andrae, Johanna; Afink, Gijs B.

2011-01-01

273

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

274

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.

275

Abnormalities in whisking behaviour are associated with lesions in brain stem nuclei in a mouse model of amyotrophic lateral sclerosis.  

PubMed

The transgenic SOD1(G93A) mouse is a model of human amyotrophic lateral sclerosis (ALS) and recapitulates many of the pathological hallmarks observed in humans, including motor neuron degeneration in the brain and the spinal cord. In mice, neurodegeneration particularly impacts on the facial nuclei in the brainstem. Motor neurons innervating the whisker pad muscles originate in the facial nucleus of the brain stem, with contractions of these muscles giving rise to "whisking" one of the fastest movements performed by mammals. A longitudinal study was conducted on SOD1(G93A) mice and wild-type litter mate controls, comparing: (i) whisker movements using high-speed video recordings and automated whisker tracking, and (ii) facial nucleus degeneration using MRI. Results indicate that while whisking still occurs in SOD1(G93A) mice and is relatively resistant to neurodegeneration, there are significant disruptions to certain whisking behaviours, which correlate with facial nuclei lesions, and may be as a result of specific facial muscle degeneration. We propose that measures of mouse whisker movement could potentially be used in tandem with measures of limb dysfunction as biomarkers of disease onset and progression in ALS mice and offers a novel method for testing the efficacy of novel therapeutic compounds. PMID:24239688

Grant, Robyn A; Sharp, Paul S; Kennerley, Aneurin J; Berwick, Jason; Grierson, Andrew; Ramesh, Tennore; Prescott, Tony J

2014-02-01

276

Repetitive Transcranial Magnetic Stimulation Activates Specific Regions in Rat Brain  

NASA Astrophysics Data System (ADS)

Repetitive transcranial magnetic stimulation (rTMS) is a noninvasive technique to induce electric currents in the brain. Although rTMS is being evaluated as a possible alternative to electroconvulsive therapy for the treatment of refractory depression, little is known about the pattern of activation induced in the brain by rTMS. We have compared immediate early gene expression in rat brain after rTMS and electroconvulsive stimulation, a well-established animal model for electroconvulsive therapy. Our result shows that rTMS applied in conditions effective in animal models of depression induces different patterns of immediate-early gene expression than does electroconvulsive stimulation. In particular, rTMS evokes strong neural responses in the paraventricular nucleus of the thalamus (PVT) and in other regions involved in the regulation of circadian rhythms. The response in PVT is independent of the orientation of the stimulation probe relative to the head. Part of this response is likely because of direct activation, as repetitive magnetic stimulation also activates PVT neurons in brain slices.

Ji, Ru-Rong; Schlaepfer, Thomas E.; Aizenman, Carlos D.; Epstein, Charles M.; Qiu, Dike; Huang, Justin C.; Rupp, Fabio

1998-12-01

277

Sex moderates the relationship between worry and performance monitoring brain activity in undergraduates.  

PubMed

Research suggests that abnormal performance-monitoring contributes to the etiology and maintenance of anxious pathology. Moreover, the anxiety-performance monitoring relationship appears to be specific to the worry dimension of anxiety. Given that anxiety (and worry in particular) is twice as prevalent in women as men, and most studies to date have employed small samples which are underpowered to detect sex-differences, it is possible that sex may be an important moderator of the worry-performance-monitoring relationship. No studies have directly compared the worry-performance-monitoring relationship between men and women, however. In the current study, we extended our recent work showing a unique relationship between worry and performance monitoring brain potentials in female undergraduates by comparing this relationship to that between worry and performance-monitoring brain potentials in male participants. Seventy-nine female and 70 male undergraduates from an ongoing study of anxiety and performance monitoring performed a letter-flanker task while their brain activity was recorded. Results revealed that worry was associated with exaggerated performance-monitoring, as indexed by increased error-related negativity/correct-response negativity, in female, but not male undergraduates. These findings suggest that the functional relationship between worry and performance-monitoring is sex-specific and have implications for understanding the role of performance-monitoring in the development and maintenance of anxiety. Specifically, linking the worry-performance-monitoring relationship to other female-specific biopsychosocial factors represents an important direction for future research. PMID:22659221

Moran, Tim P; Taylor, Danielle; Moser, Jason S

2012-08-01

278

Gastric distention activates satiety circuitry in the human brain.  

PubMed

Gastric distention during meal ingestion activates vagal afferents, which send signals from the stomach to the brain and result in the perception of fullness and satiety. Distention is one of the mechanisms that modulates food intake. We measured regional brain activation during dynamic gastric balloon distention in 18 health subjects using functional magnetic resonance imaging and the blood oxygenation level-dependent (BOLD) responses. The BOLD signal was significantly changed by both inflow and outflow changes in the balloon's volume. For lower balloon volumes, water inflow was associated with activation of sensorimotor cortices and right insula. The larger volume condition additionally activated left posterior amygdala, left posterior insula and the left precuneus. The response in the left amygdala and insula was negatively associated with changes in self-reports of fullness and positively with changes in plasma ghrelin concentration, whereas those in the right amygdala and insula were negatively associated with the subject's body mass index. The widespread activation induced by gastric distention corroborates the influence of vagal afferents on cortical and subcortical brain activity. These findings provide evidence that the left amygdala and insula process interoceptive signals of fullness produced by gastric distention involved in the controls of food intake. PMID:18155924

Wang, Gene-Jack; Tomasi, Dardo; Backus, Walter; Wang, Ruiliang; Telang, Frank; Geliebter, Allan; Korner, Judith; Bauman, Angela; Fowler, Joanna S; Thanos, Panayotis K; Volkow, Nora D

2008-02-15

279

Somatic activation of AKT3 causes hemispheric developmental brain malformations.  

PubMed

Hemimegalencephaly (HMG) is a developmental brain disorder characterized by an enlarged, malformed cerebral hemisphere, typically causing epilepsy that requires surgical resection. We studied resected HMG tissue to test whether the condition might reflect somatic mutations affecting genes critical to brain development. We found that two out of eight HMG samples showed trisomy of chromosome 1q, which encompasses many genes, including AKT3, a gene known to regulate brain size. A third case showed a known activating mutation in AKT3 (c.49G?A, creating p.E17K) that was not present in the patient's blood cells. Remarkably, the E17K mutation in AKT3 is exactly paralogous to E17K mutations in AKT1 and AKT2 recently discovered in somatic overgrowth syndromes. We show that AKT3 is the most abundant AKT paralog in the brain during neurogenesis and that phosphorylated AKT is abundant in cortical progenitor cells. Our data suggest that somatic mutations limited to the brain could represent an important cause of complex neurogenetic disease. PMID:22500628

Poduri, Annapurna; Evrony, Gilad D; Cai, Xuyu; Elhosary, Princess Christina; Beroukhim, Rameen; Lehtinen, Maria K; Hills, L Benjamin; Heinzen, Erin L; Hill, Anthony; Hill, R Sean; Barry, Brenda J; Bourgeois, Blaise F D; Riviello, James J; Barkovich, A James; Black, Peter M; Ligon, Keith L; Walsh, Christopher A

2012-04-12

280

The effects of hyperammonemia in learning and brain metabolic activity.  

PubMed

Ammonia is thought to be central in the development of hepatic encephalopathy. However, the specific relation of ammonia with brain energy depletions and learning has not been studied. Our work attempts to reproduce an increase in rat cerebral ammonia level, study the hyperamonemic animals' performance of two learning tasks, an allocentric (ALLO) and a cue guided (CG) task, and elucidate the contribution of hyperammonemia to the differential energy requirements of the brain limbic system regions involved in these tasks. To assess these goals, four groups of animals were used: a control (CHA) CG group (n?=?10), a CHA ALLO group (n?=?9), a hyperammonemia (HA) CG group (n?=?7), and HA ALLO group (n?=?8). Oxidative metabolism of the target brain regions were assessed by histochemical labelling of cytochrome oxidase (C.O.). The behavioural results revealed that the hyperammonemic rats were not able to reach the behavioural criterion in either of the two tasks, in contrast to the CHA groups. The metabolic brain consumption revealed increased C.O. activity in the anterodorsal thalamus when comparing the HA ALLO group with the CHA ALLO group. Significant differences between animals trained in the CG task were observed in the prelimbic, infralimbic, parietal, entorhinal and perirhinal cortices, the anterolateral and anteromedial striatum, and the basolateral and central amygdala. Our findings may provide fresh insights to reveal how the differential damage to the brain limbic structures involved in these tasks differs according to the degree of task difficulty. PMID:24415107

Arias, Natalia; Fidalgo, Camino; Felipo, Vicente; Arias, Jorge L

2014-03-01

281

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

282

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

283

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

284

Human brain activity during spontaneously reversing perception of ambiguous figures.  

PubMed Central

Looking at ambiguous figures results in rivalry with spontaneous alternation between two percepts. Using event-related functional magnetic resonance imaging, we localized transient human brain activity changes during perceptual reversals. Activation occurred in ventral occipital and intraparietal higher-order visual areas, deactivation in primary visual cortex and the pulvinar. Thus, without any physical stimulus changes, salient perceptual flips briefly engage widely separated specialized cortical areas, but are also associated with intermittent activity breakdown in structures putatively maintaining perceptual stability. Together, the dynamics of integrative perceptual experience are reflected in rapid spatially differentiated activity modulation within a cooperative set of neural structures.

Kleinschmidt, A; Buchel, C; Zeki, S; Frackowiak, R S

1998-01-01

285

Abnormal Initiation and Conduction of Slow-Wave Activity in Gastroparesis, Defined by High-Resolution Electrical Mapping  

PubMed Central

Background & Aims Interstitial cells of Cajal (ICC) generate slow waves. Disrupted ICC networks and gastric dysrhythmias are each associated with gastroparesis. However, there are no data on the initiation and propagation of slow waves in gastroparesis, because research tools have lacked spatial resolution. We applied high-resolution electrical mapping to quantify and classify gastroparesis slow-wave abnormalities in spatiotemporal detail. Methods Serosal HR mapping was performed, using flexible arrays (256 electrodes; 36 cm2), at stimulator implantation in 12 patients with diabetic or idiopathic gastroparesis. Data were analyzed by isochronal mapping, velocity and amplitude field mapping, and propagation animation. ICC numbers were determined from gastric biopsies. Results Mean ICC counts were reduced in patients with gastroparesis (2.3 vs 5.4 bodies/field; P<.001). Slow-wave abnormalities were detected by HR mapping in 11/12 patients. Several new patterns were observed and classified as ‘abnormal initiation’ (10/12; stable ectopic pacemakers or diffuse focal events; median 3.3 c/min, range 2.1-5.7), or ‘abnormal conduction’ (7/10; reduced velocities or conduction blocks; median 2.9 c/min; range 2.1-3.6). Circumferential conduction emerged during aberrant initiation or incomplete block and was associated with velocity elevation (7.3 vs 2.9 mm s?1; P=.002) and increased amplitudes beyond a low base value (415 vs 170 ?V; P=.002). Conclusions HR mapping revealed new categories of abnormal human slow-wave activity. Abnormalities of slow-wave initiation and conduction occur in gastroparesis, often at normal frequency, which could be missed by tests that lack spatial resolution. Irregular initiation, aberrant conduction, and low amplitude activity could contribute to the pathogenesis of gastroparesis.

O'Grady, Gregory; Angeli, Timothy R.; Du, Peng; Lahr, Chris; Lammers, Wim JEP; Windsor, John A.; Abell, Thomas L.; Farrugia, Gianrico; Pullan, Andrew J.; Cheng, Leo K.

2012-01-01

286

Interindividual synchronization of brain activity during live verbal communication.  

PubMed

Verbal social interaction plays an important role both in the etiology and treatment of psychiatric disorders. However, the neural basis of social interaction has primarily been studied in the individual brain, neglecting the inter-individual perspective. Here, we show inter-individual neuronal coupling of brain activity during live verbal interaction, by investigating 11 pairs of good female friends who were instructed to speak about autobiographical life events during simultaneous fMRI acquisition. The analysis revealed that the time course of neural activity in areas associated with speech production was coupled with the time course of neural activity in the interlocutor's auditory cortex. This shows the feasibility of the new methodology, which may help elucidate basic reciprocal mechanisms of social interaction and the underpinnings of disordered communication. In particular, it may serve to study the process of psychotherapy on a neuronal level. PMID:24144548

Spiegelhalder, Kai; Ohlendorf, Sabine; Regen, Wolfram; Feige, Bernd; Tebartz van Elst, Ludger; Weiller, Cornelius; Hennig, Jürgen; Berger, Mathias; Tüscher, Oliver

2014-01-01

287

Auditory perception of music measured by brain electrical activity mapping.  

PubMed

The brain electrical activity of right-handed normal subjects was studied while they were exposed to auditory stimulation of the music type. The material presented was a note, a scale and a melody, recorded on magnetic tape. Each stimulus condition lasted 45 sec. The first 30 sec were analysed using brain electrical activity mapping in the delta (1-4 Hz), alpha (8-12 Hz) and beta 2 (18-24 Hz) frequency bands. The results showed significant bilateral reaction differences for all conditions, showing a left midtemporal activation predominance for the note and scale conditions, but a right midtemporal and frontal predominance for the melody. The results are discussed in terms of functional specialization for different levels of processing. PMID:3431673

Breitling, D; Guenther, W; Rondot, P

1987-01-01

288

Structural brain abnormalities in patients with Parkinson's disease with visual hallucinations: A comparative voxel-based analysis.  

PubMed

The objective is to evaluate clinical characteristics and cerebral alterations in Parkinson's disease (PD) patients with diurnal visual hallucinations (VHs). Assessment was performed using magnetic resonance image (MRI) and voxel-based morphometry (VBM). Thirty-nine patients with PD (53.8%) and ten controls were studied. Voxel based morphology analysis was performed. Eleven patients presented diurnal VHs and among these, six had cognitive dysfunction. Patients with VHs performed worse in the mentation-related UPDRS I (p=0.005) and motor-related UPDRS III (p=0.02). Patients with VHs showed significant clusters of reduced grey matter volume compared to controls in the left opercula frontal gyrus and left superior frontal gyrus. PD without hallucinations demonstrated reduced grey matter volume in the left superior frontal gyrus compared to controls. Comparisons between patients with VHs regarding the presence of cognitive dysfunction showed that cases with cognitive dysfunction as compared to those without cognitive dysfunction showed significant clusters of reduced grey matter volume in the left opercular frontal gyrus. Cases without cognitive dysfunction had reduced grey matter substance in the left insula and left trigonal frontal gyrus. Judging from our findings, an abnormal frontal cortex, particularly left sided insula, frontal opercular, trigonal frontal gyrus and orbital frontal would make PD patients vulnerable to hallucinations. Compromise of the left operculum distinguished cases with VHs and cognitive dysfunction. Our findings reinforce the theoretical concept of a top-down visual processing in the genesis of VHs in PD. PMID:24732953

Gama, Romulo Lopes; Bruin, Veralice Meireles Sales; Távora, Daniel Gurgel Fernandes; Duran, Fábio L S; Bittencourt, Lia; Tufik, Sergio

2014-06-01

289

Spatiotemporal tuning of brain activity and force performance.  

PubMed

The spatial and temporal features of visual stimuli are either processed independently or are conflated in specific cells of visual cortex. Although spatial and temporal features of visual stimuli influence motor performance, it remains unclear how spatiotemporal information is processed beyond visual cortex in brain regions that control movement. We used functional magnetic resonance imaging to examine how brain activity and force control are influenced by visual gain at a high visual feedback frequency of 6.4 Hz and a low visual feedback frequency of 0.4 Hz. At 6.4 Hz, increasing visual gain led to improved force performance and increased activity in classic areas of the visuomotor system-V5, IPL, SPL, PMv, SMA-proper, and M1. At 0.4 Hz, increasing gain also led to improved force performance. In addition to activation in M1/PMd and IPL in the visuomotor system, increasing visual gain at 0.4 Hz also corresponded with activity in the striatal-frontal circuit including DLPFC, ACC, and widespread activity in putamen, caudate, and SMA-proper. This study demonstrates that the frequency of visual feedback drives where in the brain visual gain mediated reductions in force error are regulated. PMID:20937396

Coombes, Stephen A; Corcos, Daniel M; Vaillancourt, David E

2011-02-01

290

Spatiotemporal tuning of brain activity and force performance  

PubMed Central

The spatial and temporal features of visual stimuli are either processed independently or are conflated in specific cells of visual cortex. Although spatial and temporal features of visual stimuli influence motor performance, it remains unclear how spatiotemporal information is processed beyond visual cortex in brain regions that control movement. We used functional magnetic resonance imaging to examine how brain activity and force control are influenced by visual gain at a high visual feedback frequency of 6.4 Hz and a low visual feedback frequency of 0.4 Hz. At 6.4 Hz, increasing visual gain led to improved force performance and increased activity in classic areas of the visuomotor system – V5, IPL, SPL, PMv, SMA-proper, and M1. At 0.4 Hz, increasing gain also lead to improved force performance. In addition to activation in M1/PMd and IPL in the visuomotor system, increasing visual gain at 0.4 Hz also corresponded with activity in the striatal-frontal circuit including DLPFC, ACC, and widespread activity in putamen, caudate, and SMA-proper. This study demonstrates that the frequency of visual feedback drives where in the brain visual gain mediated reductions in force error are regulated.

Coombes, Stephen A.; Corcos, Daniel M.; Vaillancourt, David E.

2010-01-01

291

Motor cortex microcircuit simulation based on brain activity mapping.  

PubMed

The deceptively simple laminar structure of neocortex belies the complexity of intra- and interlaminar connectivity. We developed a computational model based primarily on a unified set of brain activity mapping studies of mouse M1. The simulation consisted of 775 spiking neurons of 10 cell types with detailed population-to-population connectivity. Static analysis of connectivity with graph-theoretic tools revealed that the corticostriatal population showed strong centrality, suggesting that would provide a network hub. Subsequent dynamical analysis confirmed this observation, in addition to revealing network dynamics that cannot be readily predicted through analysis of the wiring diagram alone. Activation thresholds depended on the stimulated layer. Low stimulation produced transient activation, while stronger activation produced sustained oscillations where the threshold for sustained responses varied by layer: 13% in layer 2/3, 54% in layer 5A, 25% in layer 5B, and 17% in layer 6. The frequency and phase of the resulting oscillation also depended on stimulation layer. By demonstrating the effectiveness of combined static and dynamic analysis, our results show how static brain maps can be related to the results of brain activity mapping. PMID:24708371

Chadderdon, George L; Mohan, Ashutosh; Suter, Benjamin A; Neymotin, Samuel A; Kerr, Cliff C; Francis, Joseph T; Shepherd, Gordon M G; Lytton, William W

2014-07-01

292

Dominant frequencies of resting human brain activity as measured by the electrocorticogram.  

PubMed

The brain's spontaneous, intrinsic activity is increasingly being shown to reveal brain function, delineate large scale brain networks, and diagnose brain disorders. One of the most studied and clinically utilized types of intrinsic brain activity are oscillations in the electrocorticogram (ECoG), a relatively localized measure of cortical synaptic activity. Here we objectively characterize the types of ECoG oscillations commonly observed over particular cortical areas when an individual is awake and immobile with eyes closed, using a surface-based cortical atlas and cluster analysis. Both methods show that [1] there is generally substantial variability in the dominant frequencies of cortical regions and substantial overlap in dominant frequencies across the areas sampled (primarily lateral central, temporal, and frontal areas), [2] theta (4-8 Hz) is the most dominant type of oscillation in the areas sampled with a mode around 7 Hz, [3] alpha (8-13 Hz) is largely limited to parietal and occipital regions, and [4] beta (13-30 Hz) is prominent peri-Rolandically, over the middle frontal gyrus, and the pars opercularis. In addition, the cluster analysis revealed seven types of ECoG spectral power densities (SPDs). Six of these have peaks at 3, 5, 7 (narrow), 7 (broad), 10, and 17 Hz, while the remaining cluster is broadly distributed with less pronounced peaks at 8, 19, and 42 Hz. These categories largely corroborate conventional sub-gamma frequency band distinctions (delta, theta, alpha, and beta) and suggest multiple sub-types of theta. Finally, we note that gamma/high gamma activity (30+ Hz) was at times prominently observed, but was too infrequent and variable across individuals to be reliably characterized. These results should help identify abnormal patterns of ECoG oscillations, inform the interpretation of EEG/MEG intrinsic activity, and provide insight into the functions of these different oscillations and the networks that produce them. Specifically, our results support theories of the importance of theta oscillations in general cortical function, suggest that alpha activity is primarily related to sensory processing/attention, and demonstrate that beta networks extend far beyond primary sensorimotor regions. PMID:23639261

Groppe, David M; Bickel, Stephan; Keller, Corey J; Jain, Sanjay K; Hwang, Sean T; Harden, Cynthia; Mehta, Ashesh D

2013-10-01

293

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

PubMed

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

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

2013-11-01

294

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

295

Fast transient networks in spontaneous human brain activity  

PubMed Central

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

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

2014-01-01

296

Measuring relative timings of brain activities using fMRI.  

PubMed

Functional MRI (fMRI) has previously been shown to be able to measure hundreds of milliseconds differences in timings of activities in different brain regions, even though the underlying blood oxygenation level-dependent (BOLD) response is delayed and dispersed on the order of seconds. This capability may contribute towards the study of communication within the brain by assessing the temporal sequences of various brain processes (mental chronometry). The practical limit of fMRI for detecting the relative timing of brain activity is not known. We aimed to detect fine differences in the timings of brain activities beyond those previously measured from fMRI data in human subjects. We introduced known delays between the onsets of visual stimuli in a controlled, sparse event-related design and investigated if the temporal shifts in the corresponding average BOLD signals were detectable. To maximize sensitivity, we used high spatial and temporal resolution fMRI at ultrahigh field (7 T), in conjunction with a novel data-driven technique for voxel selection using graph-based visualizations of self-organizing maps and Granger causality to measure relative timing. This approach detected timing differences as small as 28ms in visual cortex in individual subjects. For signal extraction, the self-organizing map approach outperformed other common techniques including independent component analysis, voxelwise univariate linear regression analysis and a separate localizer scan. For relative timing measurement, Granger causality outperformed time-to-peak calculations derived from an inverse logit curve fit. We conclude that high-resolution imaging at ultrahigh field, signal extraction via self-organizing map, and appropriate use of Granger causality permit the detection of small timing differences in fMRI data, despite the intrinsically slow hemodynamic response. PMID:23110880

Katwal, Santosh B; Gore, John C; Gatenby, J Christopher; Rogers, Baxter P

2012-10-27

297

Measuring Relative Timings of Brain Activities Using FMRI  

PubMed Central

Functional MRI (fMRI) has previously been shown to be able to measure hundreds of milliseconds differences in timings of activities in different brain regions, even though the underlying blood oxygenation level-dependent (BOLD) response is delayed and dispersed on the order of seconds. This capability may contribute towards the study of communication within the brain by assessing the temporal sequences of various brain processes (mental chronometry). The practical limit of fMRI for detecting the relative timings of brain activities is not known. We aimed to detect fine differences in the timings of brain activities beyond those previously measured from fMRI data in human subjects. We introduced known delays between the onsets of visual stimuli in a controlled, sparse event-related design and investigated if the temporal shifts in the corresponding average BOLD signals were detectable. To maximize sensitivity, we used high spatial and temporal resolution fMRI at ultrahigh field (7 Tesla), in conjunction with a novel data-driven technique for voxel selection using graph-based visualizations of self-organizing maps and Granger causality to measure relative timing. This approach detected timing differences as small as 28 ms in visual cortex in individual subjects. For signal extraction, the self-organizing map approach outperformed other common techniques including independent component analysis, voxelwise univariate linear regression analysis and a separate localizer scan. For relative timing measurement, Granger causality outperformed time-to-peak calculations derived from an inverse logit curve fit. We conclude that high-resolution imaging at ultrahigh field, signal extraction via self-organizing map, and appropriate use of Granger causality permit the detection of small timing differences in fMRI data, despite the intrinsically slow hemodynamic response.

Katwal, Santosh B.; Gore, John C.; Gatenby, J. Christopher; Rogers, Baxter P.

2012-01-01

298

Emotions promote social interaction by synchronizing brain activity across individuals  

PubMed Central

Sharing others’ emotional states may facilitate understanding their intentions and actions. Here we show that networks of brain areas “tick together” in participants who are viewing similar emotional events in a movie. Participants’ brain activity was measured with functional MRI while they watched movies depicting unpleasant, neutral, and pleasant emotions. After scanning, participants watched the movies again and continuously rated their experience of pleasantness–unpleasantness (i.e., valence) and of arousal–calmness. Pearson’s correlation coefficient was used to derive multisubject voxelwise similarity measures [intersubject correlations (ISCs)] of functional MRI data. Valence and arousal time series were used to predict the moment-to-moment ISCs computed using a 17-s moving average. During movie viewing, participants' brain activity was synchronized in lower- and higher-order sensory areas and in corticolimbic emotion circuits. Negative valence was associated with increased ISC in the emotion-processing network (thalamus, ventral striatum, insula) and in the default-mode network (precuneus, temporoparietal junction, medial prefrontal cortex, posterior superior temporal sulcus). High arousal was associated with increased ISC in the somatosensory cortices and visual and dorsal attention networks comprising the visual cortex, bilateral intraparietal sulci, and frontal eye fields. Seed-voxel–based correlation analysis confirmed that these sets of regions constitute dissociable, functional networks. We propose that negative valence synchronizes individuals’ brain areas supporting emotional sensations and understanding of another’s actions, whereas high arousal directs individuals’ attention to similar features of the environment. By enhancing the synchrony of brain activity across individuals, emotions may promote social interaction and facilitate interpersonal understanding.

Nummenmaa, Lauri; Glerean, Enrico; Viinikainen, Mikko; Jaaskelainen, Iiro P.; Hari, Riitta; Sams, Mikko

2012-01-01

299

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.

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

2012-01-01

300

Amusia Results in Abnormal Brain Activity following Inappropriate Intonation during Speech Comprehension  

PubMed Central

Pitch processing is a critical ability on which humans’ tonal musical experience depends, and which is also of paramount importance for decoding prosody in speech. Congenital amusia refers to deficits in the ability to properly process musical pitch, and recent evidence has suggested that this musical pitch disorder may impact upon the processing of speech sounds. Here we present the first electrophysiological evidence demonstrating that individuals with amusia who speak Mandarin Chinese are impaired in classifying prosody as appropriate or inappropriate during a speech comprehension task. When presented with inappropriate prosody stimuli, control participants elicited a larger P600 and smaller N100 relative to the appropriate condition. In contrast, amusics did not show significant differences between the appropriate and inappropriate conditions in either the N100 or the P600 component. This provides further evidence that the pitch perception deficits associated with amusia may also affect intonation processing during speech comprehension in those who speak a tonal language such as Mandarin, and suggests music and language share some cognitive and neural resources.

Jiang, Cunmei; Hamm, Jeff P.; Lim, Vanessa K.; Kirk, Ian J.; Chen, Xuhai; Yang, Yufang

2012-01-01

301

Abnormal Functional Lateralization and Activity of Language Brain Areas in Typical Specific Language Impairment (Developmental Dysphasia)  

ERIC Educational Resources Information Center

Atypical functional lateralization and specialization for language have been proposed to account for developmental language disorders, yet results from functional neuroimaging studies are sparse and inconsistent. This functional magnetic resonance imaging study compared children with a specific subtype of specific language impairment affecting…

de Guibert, Clement; Maumet, Camille; Jannin, Pierre; Ferre, Jean-Christophe; Treguier, Catherine; Barillot, Christian; Le Rumeur, Elisabeth; Allaire, Catherine; Biraben, Arnaud

2011-01-01

302

DHA and EPA reverse cystic fibrosis-related FA abnormalities by suppressing FA desaturase expression and activity  

PubMed Central

Patients and models of cystic fibrosis (CF) exhibit consistent abnormalities of polyunsaturated fatty acid composition, including decreased linoleate (LA) and docosahexaenoate (DHA) and variably increased arachidonate (AA), related in part to increased expression and activity of fatty acid desaturases. These abnormalities and the consequent CF-related pathologic manifestations can be reversed in CF mouse models by dietary supplementation with DHA. However, the mechanism is unknown. This study investigates this mechanism by measuring the effect of exogenous DHA and eicosapentaenoate (EPA) supplementation on fatty acid composition and metabolism, as well as on metabolic enzyme expression, in a cell culture model of CF. We found that both DHA and EPA suppress the expression and activity of ?5- and ?6-desaturases, leading to decreased flux through the n-3 and n-6 PUFA metabolic pathways and decreased production of AA. The findings also uncover other metabolic abnormalities, including increased fatty acid uptake and markedly increased retroconversion of DHA to EPA, in CF cells. These results indicate that the fatty acid abnormalities of CF are related to intrinsic alterations of PUFA metabolism and that they may be reversed by supplementation with DHA and EPA.

Njoroge, Sarah W.; Laposata, Michael; Katrangi, Waddah; Seegmiller, Adam C.

2012-01-01

303

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.

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

2009-01-01

304

Brain activation during a social attribution task in adolescents with moderate to severe traumatic brain injury  

PubMed Central

The ability to make accurate judgments about the mental states of others, sometimes referred to as theory of mind (ToM), is often impaired following traumatic brain injury (TBI), and this deficit may contribute to problems with interpersonal relationships. The present study used an animated social attribution task (SAT) with functional magnetic resonance imaging (fMRI) to examine structures mediating ToM in adolescents with moderate to severe TBI. The study design also included a comparison group of matched, typically developing (TD) adolescents. The TD group exhibited activation within a number of areas that are thought to be relevant to ToM, including the medial prefrontal and anterior cingulate cortex, fusiform gyrus, and posterior temporal and parietal areas. The TBI subjects had significant activation within many of these same areas, but their activation was generally more intense and excluded the medial prefrontal cortex. Exploratory regression analyses indicated a negative relation between ToM-related activation and measures of white matter integrity derived from diffusion tensor imaging, while there was also a positive relation between activation and lesion volume. These findings are consistent with alterations in the level and pattern of brain activation that may be due to the combined influence of diffuse axonal injury and focal lesions.

Scheibel, Randall S.; Newsome, Mary R.; Wilde, Elisabeth A.; McClelland, Michelle M.; Hanten, Gerri; Krawczyk, Daniel C.; Cook, Lori G.; Chu, Zili D.; Vasquez, Ana C.; Yallampalli, Ragini; Lin, Xiaodi; Hunter, Jill V.; Levin, Harvey S.

2011-01-01

305

Brain cholinesterase activity of apparently normal wild birds  

USGS Publications Warehouse

Organophosphorus and carbamate pesticides are potent anticholinesterase substances that have killed large numbers of wild birds of various species. Cause of death is diagnosed by demonstration of depressed brain cholinesterase (ChE) activity in combination with chemical detection of anticholinesterase residue in the affected specimen. ChE depression is determined by comparison of the affected specimen to normal ChE activity for a sample of control specimens of the same species, but timely procurement of controls is not always possible. Therefore, a reference file of normal whole brain ChE activity is provided for 48 species of wild birds from North America representing 11 orders and 23 families for use as emergency substitutes in diagnosis of anticholinesterase poisoning. The ChE values, based on 83 sets of wild control specimens from across the United States, are reproducible provided the described procedures are duplicated. Overall, whole brain ChE activity varied nearly three-fold among the 48 species represented, but it was usually similar for closely related species. However, some species were statistically separable in most families and some species of the same genus differed as much as 50%.

Hill, E.F.

1988-01-01

306

Sexual Dimorphism of Brain Aromatase Activity in Medaka: Induction of a Female Phenotype by Estradiol  

Microsoft Academic Search

In this study we identified sex-dependent dimorphism of brain aromatase in the teleost medaka and examined its regulation by sex steriods. We first investigated differential distribution of brain aromatase activity in sexually mature male and female medaka in serial coronal sections of the brain and identified the hypothalamic nuclei contained in each section using the brain atlas of medaka. In

Ana Clara Melo; John S. Ramsdell

307

From the Cover: Reactivation of encoding-related brain activity during memory retrieval  

Microsoft Academic Search

Neuronal models predict that retrieval of specific event information reactivates brain regions that were active during encoding of this information. Consistent with this prediction, this positron-emission tomography study showed that remembering that visual words had been paired with sounds at encoding activated some of the auditory brain regions that were engaged during encoding. After word-sound encoding, activation of auditory brain

Lars Nyberg; Reza Habib; Anthony R. McIntosh; Endel Tulving

2000-01-01

308

Brain Activation during Smooth-Pursuit Eye Movements  

Microsoft Academic Search

A potential application of studying eye movements with functional MRI (fMRI) is to examine patient populations with known eye movement dysfunction, but the reliability with which normal subjects demonstrate activity in specific brain regions has not been established. To date, fMRI studies of smooth-pursuit eye movements have used relatively small numbers of subjects and have been restricted to fixed-effects analyses.

Jody Tanabe; Jason Tregellas; David Miller; Randal G. Ross; Robert Freedman

2002-01-01

309

PKC activator therapeutic for mild traumatic brain injury in mice  

Microsoft Academic Search

Traumatic brain injury (TBI) is a frequent consequence of vehicle, sport and war related injuries. More than 90% of TBI patients suffer mild injury (mTBI). However, the pathologies underlying the disease are poorly understood and treatment modalities are limited. We report here that in mice, the potent PKC activator bryostatin1 protects against mTBI induced learning and memory deficits and reduction

Ofer Zohar; Rotem Lavy; Xiaomei Zi; Thomas J. Nelson; Jarin Hongpaisan; Chaim G. Pick; D. L. Alkon

2011-01-01

310

The role of pre-treatment white matter abnormalities in developing white matter changes following whole brain radiation: a volumetric study.  

PubMed

White matter injury is a known complication of whole brain radiation (WBRT). Little is known about the factors that predispose a patient to such injury. The current study used MR volumetrics to examine risk factors, in particular the influence of pre-treatment white matter health, in developing white matter change (WMC) following WBRT. Thirty-four patients with unilateral metastatic disease underwent FLAIR MRI pre-treatment and at several time points following treatment. The volume of abnormal FLAIR signal in the white matter was measured in the hemisphere contralateral to the diseased hemisphere at each time point. Analyses were restricted to the uninvolved hemisphere to allow for the measurement of WBRT effects without the potential confounding effects of the disease on imaging findings. The relationship between select pre-treatment clinical variables and the degree of WMC following treatment was examined using correlational and regression based analyses. Age when treated and volume of abnormal FLAIR prior to treatment were significantly associated with WMC following WBRT; however, pre-treatment FLAIR volume was the strongest predictor of post-treatment WMCs. Age did not add any predictive value once white matter status was considered. No significant relationships were found between biological equivalent dose and select cerebrovascular risk factors (total glucose, blood pressure, BMI) and development of WMCs. The findings from this study identify pre-treatment white matter health as an important risk factor in developing WMC following WBRT. This information can be used to make more informed decisions and counsel patients on their risk for treatment effects. PMID:23813291

Sabsevitz, David S; Bovi, Joseph A; Leo, Peter D; Laviolette, Peter S; Rand, Scott D; Mueller, Wade M; Schultz, Christopher J

2013-09-01

311

Frequency Dependent Alterations in Regional Homogeneity of Baseline Brain Activity in Schizophrenia  

PubMed Central

Low frequency oscillations are essential in cognitive function impairment in schizophrenia. While functional connectivity can reveal the synchronization between distant brain regions, the regional abnormalities in task-independent baseline brain activity are less clear, especially in specific frequency bands. Here, we used a regional homogeneity (ReHo) method combined with resting-state functional magnetic resonance imaging to investigate low frequency spontaneous neural activity in the three different frequency bands (slow-5?0.01–0.027 Hz; slow-4?0.027–0.08 Hz; and typical band: 0.01–0.08 Hz) in 69 patients with schizophrenia and 62 healthy controls. Compared with controls, schizophrenia patients exhibited decreased ReHo in the precentral gyrus, middle occipital gyrus, and posterior insula, whereas increased ReHo in the medial prefrontal cortex and anterior insula. Significant differences in ReHo between the two bands were found in fusiform gyrus and superior frontal gyrus (slow-4> slow-5), and in basal ganglia, parahippocampus, and dorsal middle prefrontal gyrus (slow-5> slow-4). Importantly, we identified significant interaction between frequency bands and groups in the inferior occipital gyrus and caudate body. This study demonstrates that ReHo changes in schizophrenia are widespread and frequency dependent.

Wang, Hsiao-Lan Sharon; Liu, Chih-Min; Liu, Chen-Chung; Hwang, Tzung-Jeng; Chien, Yi-Ling; Hwu, Hai-Gwo; Tseng, Wen-Yih Isaac

2013-01-01

312

Walking abnormalities  

MedlinePLUS

Gait abnormalities ... of how a person walks is called the gait. Different types of walking problems occur without a ... Some walking abnormalities have been given names: Propulsive gait -- a stooped, stiff posture with the head and ...

313

Glutathione peroxidase activity modulates recovery in the injured immature brain  

PubMed Central

Objective Mice subjected to traumatic brain injury (TBI) at postnatal day (pnd) 21 show emerging cognitive deficits that coincide with hippocampal neuronal loss. Here we consider glutathione peroxidase (GPx) activity as a determinant of recovery in the injured immature brain. Methods Wildtype (WT) and transgenic (GPxTg) mice overexpressing GPx were subjected to TBI or sham surgery at pnd 21. Animals were euthanized acutely (3 or 24 hours postinjury) to assess oxidative stress and cell injury in the hippocampus or 4 months postinjury following behavioral assessments. Results In the acutely injured brains, a reduction in oxidative stress markers including nitrotyrosine was seen in the injured GPxTg group relative to WT controls. In contrast, cell injury, with marked vulnerability in the dentate gyrus, was apparent despite no differences between genotypes. Magnetic resonance imaging demonstrated an emerging cortical lesion during brain maturation that was also indistinguishable between injured genotypes. Stereologic analyses of cortical volumes likewise confirmed no genotypic differences between injured groups. However, behavioral tests beginning 3 months after injury demonstrated improved spatial memory learning in the GPxTg group. Moreover, Stereologic analysis within hippocampal subregions revealed a significantly greater number of neurons within the dentate of the GPx group. Interpretation Our results implicate GPx in recovery of spatial memory after TBI. This recovery may be in part attributed to a reduction in early oxidative stress and selective, long-term sparing of neurons in the dentate.

Tsuru-Aoyagi, Kyoko; Potts, Matthew B.; Trivedi, Alpa; Pfankuch, Timothy; Raber, Jacob; Wendland, Michael; Claus, Catherine; Koh, Seong-Eun; Ferriero, Donna; Noble-Haeusslein, Linda J.

2009-01-01

314

Learning sculpts the spontaneous activity of the resting human brain  

PubMed Central

The brain is not a passive sensory-motor analyzer driven by environmental stimuli, but actively maintains ongoing representations that may be involved in the coding of expected sensory stimuli, prospective motor responses, and prior experience. Spontaneous cortical activity has been proposed to play an important part in maintaining these ongoing, internal representations, although its functional role is not well understood. One spontaneous signal being intensely investigated in the human brain is the interregional temporal correlation of the blood-oxygen level-dependent (BOLD) signal recorded at rest by functional MRI (functional connectivity-by-MRI, fcMRI, or BOLD connectivity). This signal is intrinsic and coherent within a number of distributed networks whose topography closely resembles that of functional networks recruited during tasks. While it is apparent that fcMRI networks reflect anatomical connectivity, it is less clear whether they have any dynamic functional importance. Here, we demonstrate that visual perceptual learning, an example of adult neural plasticity, modifies the resting covariance structure of spontaneous activity between networks engaged by the task. Specifically, after intense training on a shape-identification task constrained to one visual quadrant, resting BOLD functional connectivity and directed mutual interaction between trained visual cortex and frontal-parietal areas involved in the control of spatial attention were significantly modified. Critically, these changes correlated with the degree of perceptual learning. We conclude that functional connectivity serves a dynamic role in brain function, supporting the consolidation of previous experience.

Lewis, Christopher M.; Baldassarre, Antonello; Committeri, Giorgia; Romani, Gian Luca; Corbetta, Maurizio

2009-01-01

315

Chlorpromazine confers neuroprotection against brain ischemia by activating BKCa channel.  

PubMed

Chlorpromazine (CPZ) is a well-known antipsychotic drug, still widely being used to treat symptoms of schizophrenia, psychotic depression and organic psychoses. We have previously reported that CPZ activates the BKCa (KCa1.1) channel at whole cell level. In the present study, we demonstrated that CPZ increased the single channel open probability of the BKCa channels without changing its single channel amplitude. As BKCa channel is one of the molecular targets of brain ischemia, we explored a possible new use of this old drug on ischemic brain injury. In middle cerebral artery occlusion (MCAO) focal cerebral ischemia, a single intraperitoneal injection of CPZ at several dosages (5mg/kg, 10mg/kg and 20mg/kg) could exert a significant neuroprotective effect on the brain damage in a dose- and time-dependent manner. Furthermore, blockade of BKCa channels abolished the neuroprotective effect of CPZ on MCAO, suggesting that the effect of CPZ is mediated by activation of the BKCa channel. These results demonstrate that CPZ could reduce focal cerebral ischemic damage through activating BKCa channels and merits exploration as a potential therapeutic agent for treating ischemic stroke. PMID:24755143

Li, Hua-Juan; Zhang, Yu-Jiao; Zhou, Li; Han, Feng; Wang, Ming-Yan; Xue, Mao-Qiang; Qi, Zhi

2014-07-15

316

Brain mechanical property measurement using MRE with intrinsic activation.  

PubMed

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. PMID:23079508

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

2012-11-21

317

Brain Mechanical Property Measurement Using MRE with Intrinsic Activation  

PubMed Central

Problem Addressed 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. Methodology 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. Results, Significance and Potential Impact 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 6 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 MR elastography 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.

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

2013-01-01

318

Newborn's brain activity signals the origin of word memories  

PubMed Central

Recent research has shown that specific areas of the human brain are activated by speech from the time of birth. However, it is currently unknown whether newborns' brains also encode and remember the sounds of words when processing speech. The present study investigates the type of information that newborns retain when they hear words and the brain structures that support word-sound recognition. Forty-four healthy newborns were tested with the functional near-infrared spectroscopy method to establish their ability to memorize the sound of a word and distinguish it from a phonetically similar one, 2 min after encoding. Right frontal regions—comparable to those activated in adults during retrieval of verbal material—showed a characteristic neural signature of recognition when newborns listened to a test word that had the same vowel of a previously heard word. In contrast, a characteristic novelty response was found when a test word had different vowels than the familiar word, despite having the same consonants. These results indicate that the information carried by vowels is better recognized by newborns than the information carried by consonants. Moreover, these data suggest that right frontal areas may support the recognition of speech sequences from the very first stages of language acquisition.

Benavides-Varela, Silvia; Hochmann, Jean-Remy; Macagno, Francesco; Nespor, Marina; Mehler, Jacques

2012-01-01

319

Mapping the genetic variation of executive attention onto brain activity  

PubMed Central

Brain imaging data have repeatedly shown that the anterior cingulate cortex is an important node in the brain network mediating conflict. We previously reported that polymorphisms in dopamine receptor (DRD4) and monoamine oxidase A (MAOA) genes showed significant associations with efficiency of handling conflict as measured by reaction time differences in the Attention Network Test (ANT). To examine whether this genetic variation might contribute to differences in brain activation within the anterior cingulate cortex, we genotyped 16 subjects for the DRD4 and MAOA genes who had been scanned during the ANT. In each of the two genes previously associated with more efficient handling of conflict in reaction time experiments, we found a polymorphism in which persons with the allele associated with better behavioral performance showed significantly more activation in the anterior cingulate while performing the ANT than those with the allele associated with worse performance. The results demonstrate how genetic differences among individuals can be linked to individual differences in neuromodulators and in the efficiency of the operation of an appropriate attentional network.

Fan, Jin; Fossella, John; Sommer, Tobias; Wu, Yanghong; Posner, Michael I.

2003-01-01

320

Source localization of brain activity using helium-free interferometer  

NASA Astrophysics Data System (ADS)

To detect extremely small magnetic fields generated by the human brain, currently all commercial magnetoencephalography (MEG) systems are equipped with low-temperature (low-Tc) 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-Tc 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-Tc SQUID-based MEG systems.

Dammers, Jürgen; Chocholacs, Harald; Eich, Eberhard; Boers, Frank; Faley, Michael; Dunin-Borkowski, Rafal E.; Jon Shah, N.

2014-05-01

321

Exome sequencing identifies a de novo SCN2A mutation in a patient with intractable seizures, severe intellectual disability, optic atrophy, muscular hypotonia, and brain abnormalities.  

PubMed

Epilepsy is a phenotypically and genetically highly heterogeneous disorder with >200 genes linked to inherited forms of the disease. To identify the underlying genetic cause in a patient with intractable seizures, optic atrophy, severe intellectual disability (ID), brain abnormalities, and muscular hypotonia, we performed exome sequencing in a 5-year-old girl and her unaffected parents. In the patient, we detected a novel, de novo missense mutation in the SCN2A (c.5645G>T; p.R1882L) gene encoding the ?II -subunit of the voltage-gated sodium channel Nav 1.2. A literature review revealed 33 different SCN2A mutations in 14 families with benign forms of epilepsy and in 21 cases with severe phenotypes. Although almost all benign mutations were inherited, the majority of severe mutations occurred de novo. Of interest, de novo SCN2A mutations have also been reported in five patients without seizures but with ID (n = 3) and/or autism (n = 3). In the present study, we successfully used exome sequencing to detect a de novo mutation in a genetically heterogeneous disorder with epilepsy and ID. Using this approach, we expand the phenotypic spectrum of SCN2A mutations. Our own and literature data indicate that SCN2A-linked severe phenotypes are more likely to be caused by de novo mutations. A PowerPoint slide summarizing this article is available for download in the Supporting Information section here. PMID:24579881

Baasch, Anna-Lena; Hüning, Irina; Gilissen, Christian; Klepper, Joerg; Veltman, Joris A; Gillessen-Kaesbach, Gabriele; Hoischen, Alexander; Lohmann, Katja

2014-04-01

322

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

323

Contribution of Abnormal Sarcoplasmic Reticulum ATPase Activity to Systolic and Diastolic Dysfunction in Human Heart Failure  

Microsoft Academic Search

Two of the most significant characteristics of failing human myocardium are an increased diastolic [Ca2+]iand a prolonged diastolic relaxation. These abnormalities are more pronounced at higher frequencies of stimulation and may be caused by an altered Ca2+resequestration into the sarcoplasmic reticulum (SR). The force–frequency relationship was determined in multicellular preparations obtained from non-failing (n=6) and failing human myocardium (n=11). The

Ulrich Schmidt; Roger J. Hajjar; Patrick A. Helm; Catherine S. Kim; Angelia A. Doye; Judith K. Gwathmey

1998-01-01

324

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

325

Effects of cognitive-behavioral therapy on brain activation in specific phobia  

Microsoft Academic Search

Little is known about the effects of successful psychotherapy on brain function in subjects with anxiety disorders. The present study aimed to identify changes in brain activation following cognitive-behavioral therapy (CBT) in subjects suffering from specific phobia. Using functional magnetic resonance imaging (fMRI), brain activation to spider videos was measured in 28 spider phobic and 14 healthy control subjects. Phobics

Thomas Straube; Madlen Glauer; Stefan Dilger; Hans-Joachim Mentzel; Wolfgang H. R. Miltner

2006-01-01

326

EEG Asymmetry Analysis of the Left and Right Brain Activities During Simple versus Complex Arithmetic Learning  

Microsoft Academic Search

Introduction. Repeated practice of simple arithmetic such as addition, subtraction, and multiplication has been widely used for effective math education. Brain activity patterns during simple and complex arithmetic calculation have been explored by several research groups using magnetic resonance images (MRI) and functional MRI (fMRI), and some have reported that the balanced whole brain (both left and right brain) activities

Hyungkyu Kwon; Jangsik Cho; Eunjung Lee

2009-01-01

327

Electrocortical brain activity during hypoxia and hypotension in anesthetized newborn lambs  

Microsoft Academic Search

Blood gas and blood pressure disturbances do influence cerebral blood flow in newborns. To what extent cerebral blood flow changes affect electrocortical brain activity remains uncertain. We studied the effect of severe hypoxia and hemorrhagic hypotension on carotid artery blood flow and electrocortical brain activity in newborn anesthetized lambs. During hypoxia carotid artery blood flow increased significantly, whereas electrocortical brain

Margot van de Bor; Janneke Meinesz; Manon J. N. L. Benders; Paul Steendijk; Frank van Bel

1999-01-01

328

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.

2013-01-01

329

Brain activity in adults who stutter: Similarities across speaking tasks and correlations with stuttering frequency and speaking rate  

PubMed Central

Many differences in brain activity have been reported between persons who stutter (PWS) and typically fluent controls during oral reading tasks. An earlier meta-analysis of imaging studies identified stutter-related regions, but recent studies report less agreement with those regions. A PET study on adult dextral PWS (n = 18) and matched fluent controls (CONT, n = 12) is reported that used both oral reading and monologue tasks. After correcting for speech rate differences between the groups the task-activation differences were surprisingly small. For both analyses only some regions previously considered stutter-related were more activated in the PWS group than in the CONT group, and these were also activated during eyes-closed rest (ECR). In the PWS group, stuttering frequency was correlated with cortico-striatal-thalamic circuit activity in both speaking tasks. The neuroimaging findings for the PWS group, relative to the CONT group, appear consistent with neuroanatomic abnormalities being increasingly reported among PWS.

Ingham, Roger J.; Grafton, Scott T.; Bothe, Anne K.; Ingham, Janis C.

2012-01-01

330

Biochemical characterization of the active site of brain monoamine oxidase.  

PubMed

Until recently little was known concerning the chemical details of the mechanism of interaction of flavin-linked mitochondrial membrane bound monoamine oxidase (MAO) with its substrates and inhibitors. Substrates which have enzymes as their targets have been valuable in elucidating active site residues and structural features. Acetylenic amines as exemplified by clorgyline, deprenyl and pargyline are called 'suicide inhibitors' because an irreversible inhibitor is formed by the action of MAO from a relatively innocuous compound which acts as a substrate. These inhibitors can selectively inactivate MAO 'type A' and/or 'type B'. MAO isolated in homogeneous form from liver or kidney contains 1 mole of covalently bound coenzyme, cysteinyl-flavin, per mole enzyme. The flavin is bound to a pentapeptide via the thio-ether of cysteine at the 8 alpha-position of the isoalloxazine. A comparison of the inhibitory effects of clorgyline, deprenyl and pargyline on liver enzyme preparations from bovine or rat have confirmed our expectation that these irreversible inactivators form the same type of adduct with the cysteinyl-flavin active site of MAO 'type A' and 'type B', and that binding is stoichiometric at the N-5 of the covalently bound flavin in a flavocyanine linkage. Substrates protect from inhibition. In contrast to the reported observation of Tipton (39), pig brain mitochondrial MAO purified by two alternative methods contains cysteinyl-flavin in substantial amounts. The turnover number of enzyme from brain per mole of cysterinyl-flavin in apparently homogeneous samples is nearly the same as that of highly purified kidney and liver enzyme. Thus it is apparent that brain MAO also contains cysteinyl-flavin at the active center and therefore it is expected that acetylenic as well as hydrazine inhibitors form the same linkage with the flavin moiety as that formed with enzyme from peripheral tissues. A specific inhibitor for the deamination and potentiation of dopamine formed in the brain of Parkinsonian patients after treatment with L-Dopa has been regarded desirable. Deprenyl, a selective MAO 'type B inhibitor without the 'cheese effect', is the most potent inactivator of human brain MAO, and clinical results show that the drug is very useful in the treatment of Parkinson's disease and depression. PMID:6785574

Youdim, M B

1980-01-01

331

Synchronization-based approach for detecting functional activation of brain  

NASA Astrophysics Data System (ADS)

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

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

2012-09-01

332

Dynamic changes in brain activity during prism adaptation.  

PubMed

Prism adaptation does not only induce short-term sensorimotor plasticity, but also longer-term reorganization in the neural representation of space. We used event-related fMRI to study dynamic changes in brain activity during both early and prolonged exposure to visual prisms. Participants performed a pointing task before, during, and after prism exposure. Measures of trial-by-trial pointing errors and corrections allowed parametric analyses of brain activity as a function of performance. We show that during the earliest phase of prism exposure, anterior intraparietal sulcus was primarily implicated in error detection, whereas parieto-occipital sulcus was implicated in error correction. Cerebellum activity showed progressive increases during prism exposure, in accordance with a key role for spatial realignment. This time course further suggests that the cerebellum might promote neural changes in superior temporal cortex, which was selectively activated during the later phase of prism exposure and could mediate the effects of prism adaptation on cognitive spatial representations. PMID:19129395

Luauté, Jacques; Schwartz, Sophie; Rossetti, Yves; Spiridon, Mona; Rode, Gilles; Boisson, Dominique; Vuilleumier, Patrik

2009-01-01

333

Synchronization-based approach for detecting functional activation of brain.  

PubMed

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

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

2012-09-01

334

Normal-to-abnormal rearrangement and NHC activation in three-coordinate iron(II) carbene complexes.  

PubMed

The 'normal' three-coordinate iron-NHC complex [(IPr)Fe(N'')2] (N? = N(SiMe3)2) rearranges to its abnormal NHC analogue [(aIPr)Fe(N?)2] (6) on heating, providing a rare abnormal iron-aNHC complex, and the first such three-coordinate complex. The tert-butyl-substituted complex [(I(t)Bu)Fe(N?)2] (4) undergoes a thermal decomposition that has not previously been observed in iron-NHC chemistry, resulting in the bis(imidazole) complex [((t)BuIm)2Fe(N?)2] (7). A mechanism that involves consecutive C-H and C-N activation is proposed to account for the formation of 7. PMID:23978294

Day, Benjamin M; Pugh, Thomas; Hendriks, Daniël; Guerra, Célia Fonseca; Evans, David J; Bickelhaupt, F Matthias; Layfield, Richard A

2013-09-11

335

Pattern of brain activation during social cognitive tasks is related to social competence in siblings discordant for schizophrenia.  

PubMed

Measures of social competence are closely related to actual community functioning in patients with schizophrenia. However, the neurobiological mechanisms underlying competence in schizophrenia are not fully understood. We hypothesized that social deficits in schizophrenia are explained, at least in part, by abnormally lateralized patterns of brain activation in response to tasks engaging social cognition, as compared to healthy individuals. We predicted such patterns would be partly heritable, and therefore affected in patients' nonpsychotic siblings as well. We used a functional magnetic resonance image paradigm to characterize brain activation induced by theory of mind tasks, and two tests of social competence, the Test of Adaptive Behavior in Schizophrenia (TABS), and the Social Skills Performance Assessment (SSPA) in siblings discordant for schizophrenia and comparable healthy controls (n = 14 per group). Healthy individuals showed the strongest correlation between social competence and activation of right hemisphere structures involved in social cognitive processing, whereas in patients, the correlation pattern was lateralized to left hemisphere areas. Unaffected siblings of patients exhibited a pattern intermediate between the other groups. These results support the hypothesis that schizophrenia may be characterized by an abnormal functioning of nondominant hemisphere structures involved in the processing of socially salient information. PMID:24927685

Villarreal, Mirta F; Drucaroff, Lucas J; Goldschmidt, Micaela G; de Achával, Delfina; Costanzo, Elsa Y; Castro, Mariana N; Ladrón-de-Guevara, M Soledad; Busatto Filho, Geraldo; Nemeroff, Charles B; Guinjoan, Salvador M

2014-09-01

336

A gouty family with increased phosphoribosylpyrophosphate synthetase activity: case reports, familial studies, and kinetic studies of the abnormal enzyme.  

PubMed

Two male patients with urate overexcretion and clinical gout in a family showed activity of phosphoribosylpyrophosphate (PRPP) synthetase in erythrocyte lysates (3.1-fold) greater than that found in normal subjects. Hemolysates from 5 female persons in this family contained (2.7-fold) increased enzyme activity suggesting X-linked dominant transmission of the abnormality. Increased maximal velocity of the enzyme, aberrant protein pattern in polyacrylamide electrophoresis, and increased thermolability in purified enzyme suggested that this enzyme is a mutant one. From these findings, it was assumed that the characteristics of this enzyme were different from 4 previously reported enzymes. PMID:6271966

Akaoka, I; Fujimori, S; Kamatani, N; Takeuchi, F; Yano, E; Nishida, Y; Hashimoto, A; Horiuchi, Y

1981-01-01

337

Nonsurgical Brain Activity Recovery From a Cap Containing Multiple Electroencephalogram Recording Sites.  

National Technical Information Service (NTIS)

The goal of this project is to invert electroencephalogram data to brain activity using a novel and accurate algorithm. This algorithm can be used for research and development of brain-machine interfaces, potentially to include prosthetic control, surveil...

D. Cohoon

2006-01-01

338

Do You Often Recall Dreams? Your Brain Might Be More Active  

MedlinePLUS

... page, please enable JavaScript. Do You Often Recall Dreams? Your Brain Might Be More Active In French brain-scan study, 'high recallers' remembered dreams five mornings per week (*this news item will ...

339

Multi-User Facility for High Performance Optical Recording of Brain Activity (DURIP).  

National Technical Information Service (NTIS)

This equipment grant provided funds to purchase a Silicon Graphics workstation for optical recording of brain activity. The system is being used by scientists at the University of Texas and the USAF School of Aerospace Medicine to examine brain electrical...

D. Senseman

1990-01-01

340

Brain-derived neurotrophic factor and antidepressant activity.  

PubMed

Brain-derived neurotrophic factor (BDNF) is a member of the structurally and functionally homologous neurotrophin family. It is the most widely distributed trophic factor in the brain, and participates in neuronal growth, maintenance, and use-dependent plasticity mechanisms such as long-term potentiation and learning. There are several lines of evidence supporting a role for BDNF in the treatment of depression. This paper reviews the neurotrophin hypothesis of antidepressant action, and examines our current understanding of activity-dependent mechanisms of BDNF expression and function in limbic regions of the brain. Our discussion starts with the original observations of monoaminergic neurotransmitter dysfunction that served as the basis for early antidepressant drug development, and outlines evidence for neurodegeneration and functional deficits existing with chronic stress and depression. We continue with evidence that enhancement in neurotrophic support and associated augmentation in synaptic plasticity and function may form the basis for antidepressant efficacy, and serve as a current and future focus in the quest for more rapid-acting and effective medication treatments. Finally, we follow the current search for the intracellular mechanisms of antidepressant interventions that may bring the monoaminergic and neurotrophic hypotheses together, and help us to more fully understand the roles of both neurotransmitter and growth factor. Principal challenges to the neurotrophin hypothesis, and inconsistencies between clinical and preclinical research results, are also pointed out, as these also guide future experiments that will refine our understanding of treatment mechanisms. PMID:15892658

Russo-Neustadt, A A; Chen, M J

2005-01-01

341

Drug polyconsumption is associated with increased synchronization of brain electrical-activity at rest and in a counting task.  

PubMed

Drug abusers typically consume not just one but several types of drugs, starting from alcohol and marijuana consumption, and then dramatically lapsing into addiction to harder drugs, such as cocaine, heroin, or amphetamine. The brain of drug abusers presents various structural and neurophysiological abnormalities, some of which may predate drug consumption onset. However, how these changes translate into modifications in functional brain connectivity is still poorly understood. To characterize functional connectivity patterns, we recorded Electroencephalogram (EEG) activity from 21 detoxified drug abusers and 20 age-matched control subjects performing a simple counting task and at rest activity. To evaluate the cortical brain connectivity network we applied the Synchronization Likelihood algorithm. The results showed that drug abusers had higher synchronization levels at low frequencies, mainly in the ? band (4-8 Hz) between frontal and posterior cortical regions. During the counting task, patients showed increased synchronization in the ? (14-35 Hz), and ? (35-45 Hz) frequency bands, in fronto-posterior and interhemispheric temporal regions. Taken together 'slow-down' at rest and task-related 'over-exertion' could indicate that the brain of drug abusers is suffering from a premature form of ageing. Future studies will clarify whether this condition can be reversed following prolonged periods of abstinence. PMID:24344693

Coullaut-Valera, R; Arbaiza, I; Bajo, R; Arrúe, R; López, M E; Coullaut-Valera, J; Correas, A; López-Sanz, D; Maestu, F; Papo, D

2014-02-01

342

[Changes of brain electric activity under general anaesthesia (author's transl)].  

PubMed

The comparison of the influence of HAL, NLA and EHA on the electrical activity of the brain by help of a vigilo-somnogram shows equal directed curves. That is to say that the effect of general anesthesia is to be seen in a inhibition of the central nervous system, from which in the first line the orienting reticular system and pain processing centres of the limbic system are concerned. It has to be emphasized that the sleep-EEG and the EEG of general anaesthesia have a certain similarity but no identity; so the sleep state of the EEG should not be transferred to the anaesthesia states. PMID:7425263

Grabow, L; Pyhel, N

1980-07-01

343

Decoding the Representation of Numerical Values from Brain Activation Patterns  

PubMed Central

Human neuroimaging studies have increasingly converged on the possibility that the neural representation of specific numbers may be decodable from brain activity, particularly in parietal cortex. Multivariate machine learning techniques have recently demonstrated that the neural representation of individual concrete nouns can be decoded from fMRI patterns, and that some patterns are general over people. Here we use these techniques to investigate whether the neural codes for quantities of objects can be accurately decoded. The pictorial mode (nonsymbolic) depicted a set of objects pictorially (e.g., a picture of three tomatoes), whereas the digit-object mode depicted quantities as combination of a digit (e.g., 3) with a picture of a single object. The study demonstrated that quantities of objects were decodable from neural activation patterns, in parietal regions. These brain activation patterns corresponding to a given quantity were common across objects and across participants in the pictorial mode. Other important findings included better identification of individual numbers in the pictorial mode, partial commonality of neural patterns across the two modes, and hemispheric asymmetry with pictorially-depicted numbers represented bilaterally and numbers in the digit-object mode represented primarily in the left parietal regions. The findings demonstrate the ability to identify individual quantities of objects based on neural patterns, indicating the presence of stable neural representations of numbers. Additionally, they indicate a predominance of neural representation of pictorially depicted numbers over the digit-object mode.

Damarla, Saudamini Roy; Just, Marcel Adam

2014-01-01

344

Calcium imaging of infrared-stimulated activity in rodent brain.  

PubMed

Infrared neural stimulation (INS) is a promising neurostimulation technique that can activate neural tissue with high spatial precision and without the need for exogenous agents. However, little is understood about how infrared light interacts with neural tissue on a cellular level, particularly within the living brain. In this study, we use calcium sensitive dye imaging on macroscopic and microscopic scales to explore the spatiotemporal effects of INS on cortical calcium dynamics. The INS-evoked calcium signal that was observed exhibited a fast and slow component suggesting activation of multiple cellular mechanisms. The slow component of the evoked signal exhibited wave-like properties suggesting network activation, and was verified to originate from astrocytes through pharmacology and 2-photon imaging. We also provide evidence that the fast calcium signal may have been evoked through modulation of glutamate transients. This study demonstrates that pulsed infrared light can induce intracellular calcium modulations in both astrocytes and neurons, providing new insights into the mechanisms of action of INS in the brain. PMID:24674600

Cayce, Jonathan Matthew; Bouchard, Matthew B; Chernov, Mykyta M; Chen, Brenda R; Grosberg, Lauren E; Jansen, E Duco; Hillman, Elizabeth M C; Mahadevan-Jansen, Anita

2014-04-01

345

Decoding the representation of numerical values from brain activation patterns.  

PubMed

Human neuroimaging studies have increasingly converged on the possibility that the neural representation of specific numbers may be decodable from brain activity, particularly in parietal cortex. Multivariate machine learning techniques have recently demonstrated that the neural representation of individual concrete nouns can be decoded from fMRI patterns, and that some patterns are general over people. Here we use these techniques to investigate whether the neural codes for quantities of objects can be accurately decoded. The pictorial mode (nonsymbolic) depicted a set of objects pictorially (e.g., a picture of three tomatoes), whereas the digit-object mode depicted quantities as combination of a digit (e.g., 3) with a picture of a single object. The study demonstrated that quantities of objects were decodable from neural activation patterns, in parietal regions. These brain activation patterns corresponding to a given quantity were common across objects and across participants in the pictorial mode. Other important findings included better identification of individual numbers in the pictorial mode, partial commonality of neural patterns across the two modes, and hemispheric asymmetry with pictorially-depicted numbers represented bilaterally and numbers in the digit-object mode represented primarily in the left parietal regions. The findings demonstrate the ability to identify individual quantities of objects based on neural patterns, indicating the presence of stable neural representations of numbers. Additionally, they indicate a predominance of neural representation of pictorially depicted numbers over the digit-object mode. PMID:22505340

Damarla, Saudamini Roy; Just, Marcel Adam

2013-10-01

346

Slow Brain Activity (ISA/DC) Detected by MEG  

PubMed Central

Infraslow Activity (ISA), Direct Coupled (DC), or Direct Current (DC) are the terms used to describe brain activity that occurs in frequencies below 0.1Hz. ISA amplitude increase is also associated with epilepsy, traumatic brain injuries, strokes, tumors and migraines and has been studied since the early 90’s at the Henry Ford Hospital MEG Laboratory. We have used a DC based MEG system to validate and characterize the ISA from animal models of cortical spreading depression (CSD) thought to be the underlying mechanism of migraine as well as other CSD-like events seen during ischemia, anoxia, and epilepsy. MEG characterizes these slow shifts easier than EEG as there is no attenuation of these signals by the skull. In the current study we report on ISA MEG signals of 12 patients with epilepsy in the pre- and postictal state. In the minutes just prior to the onset of a seizure, large amplitude, ISA MEG waveforms were detected, signaling the onset of the seizure. It is suggested that MEG assessment of ISA, in addition to activity in the conventional frequency band, can at times be useful in the lateralization of epileptic seizures.

Bowyer, Susan M.; Shvarts, Vladimir; Moran, John E.; Mason, Karen M.; Barkley, Gregory L.; Tepley, Norman

2012-01-01

347

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

348

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

349

Deep Brain Stimulation Alleviates Parkinsonian Bradykinesia by Regularizing Pallidal Activity  

PubMed Central

Deep brain stimulation (DBS) of the basal ganglia can alleviate the motor symptoms of Parkinson's disease although the therapeutic mechanisms are unclear. We hypothesize that DBS relieves symptoms by minimizing pathologically disordered neuronal activity in the basal ganglia. In human participants with parkinsonism and clinically effective deep brain leads, regular (i.e., periodic) high-frequency stimulation was replaced with irregular (i.e., aperiodic) stimulation at the same mean frequency (130 Hz). Bradykinesia, a symptomatic slowness of movement, was quantified via an objective finger tapping protocol in the absence and presence of regular and irregular DBS. Regular DBS relieved bradykinesia more effectively than irregular DBS. A computational model of the relevant neural structures revealed that output from the globus pallidus internus was more disordered and thalamic neurons made more transmission errors in the parkinsonian condition compared with the healthy condition. Clinically therapeutic, regular DBS reduced firing pattern disorder in the computational basal ganglia and minimized model thalamic transmission errors, consistent with symptom alleviation by clinical DBS. However, nontherapeutic, irregular DBS neither reduced disorder in the computational basal ganglia nor lowered model thalamic transmission errors. Thus we show that clinically useful DBS alleviates motor symptoms by regularizing basal ganglia activity and thereby improving thalamic relay fidelity. This work demonstrates that high-frequency stimulation alone is insufficient to alleviate motor symptoms: DBS must be highly regular. Descriptive models of pathophysiology that ignore the fine temporal resolution of neuronal spiking in favor of average neural activity cannot explain the mechanisms of DBS-induced symptom alleviation.

Kuncel, Alexis M.; Birdno, Merrill J.; Turner, Dennis A.; Grill, Warren M.

2010-01-01

350

Visual attention modulates brain activation to angry voices.  

PubMed

In accordance with influential models proposing prioritized processing of threat, previous studies have shown automatic brain responses to angry prosody in the amygdala and the auditory cortex under auditory distraction conditions. However, it is unknown whether the automatic processing of angry prosody is also observed during cross-modal distraction. The current fMRI study investigated brain responses to angry versus neutral prosodic stimuli during visual distraction. During scanning, participants were exposed to angry or neutral prosodic stimuli while visual symbols were displayed simultaneously. By means of task requirements, participants either attended to the voices or to the visual stimuli. While the auditory task revealed pronounced activation in the auditory cortex and amygdala to angry versus neutral prosody, this effect was absent during the visual task. Thus, our results show a limitation of the automaticity of the activation of the amygdala and auditory cortex to angry prosody. The activation of these areas to threat-related voices depends on modality-specific attention. PMID:21715624

Mothes-Lasch, Martin; Mentzel, Hans-Joachim; Miltner, Wolfgang H R; Straube, Thomas

2011-06-29

351

Mice lacking brain-type creatine kinase activity show defective thermoregulation.  

PubMed

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 degrees 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

2009-04-20

352

Flexible, Foldable, Actively Multiplexed, High-Density Electrode Array for Mapping Brain Activity in vivo  

PubMed Central

Arrays of electrodes for recording and stimulating the brain are used throughout clinical medicine and basic neuroscience research, yet are unable to sample large areas of the brain while maintaining high spatial resolution because of the need to individually wire each passive sensor at the electrode-tissue interface. To overcome this constraint, we have developed new devices integrating ultrathin and flexible silicon nanomembrane transistors into the electrode array, enabling new dense arrays of thousands of amplified and multiplexed sensors connected using many fewer wires. We used this system to record novel spatial properties of brain activity in vivo, including sleep spindles, single-trial visual evoked responses, and electrographic seizures. Our electrode array allowed us to discover that seizures may manifest as recurrent spiral waves which propagate in the neocortex. The developments reported here herald a new generation of diagnostic and therapeutic brain-machine interface (BMI) devices.

Viventi, Jonathan; Kim, Dae-Hyeong; Vigeland, Leif; Frechette, Eric S.; Blanco, Justin A.; Kim, Yun-Soung; Avrin, Andrew E.; Tiruvadi, Vineet R.; Hwang, Suk-Won; Vanleer, Ann C.; Wulsin, Drausin F.; Davis, Kathryn; Gelber, Casey E.; Palmer, Larry; Van der Spiegel, Jan; Wu, Jian; Xiao, Jianliang; Huang, Yonggang; Contreras, Diego; Rogers, John A.; Litt, Brian

2011-01-01

353

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

2008-04-01

354

Combined defect in membrane expression and activation of platelet GPIIb--IIIa complex without primary sequence abnormalities in myeloproliferative disease.  

PubMed

Defects in glycoprotein (GP)IIb-IIIa or in its activation may cause abnormal platelet aggregation and a bleeding diathesis. We report studies in a 67-year-old man with a myeloproliferative disease and markedly abnormal platelet responses. By flow cytometry, platelet binding of two complex-specific anti-GPIIb-IIIa monoclonal antibodies (mAbs), A2A9 and 10E5, was approximately 50% of normal. An enzyme-linked immunosorbent assay (ELISA) using immobilized kistrin showed 18% of normal membrane GPIIb-IIIa complex. By immunoblot analysis, GPIIb and GPIIIa levels in platelet lysates and membranes were near normal. Activation of GPIIb-IIIa, monitored with mAb PAC-1, was markedly decreased (< 20% of normal) in response to ADP, thrombin and platelet-activating factor (PAF); expression of ligand-induced binding sites (LIBS) was < or = 30% of normal. Signal transduction-independent LIBS expression, induced by echistatin, was approximately 60% of normal, suggesting that the integrin present had intact ligand-binding capability. Sequence analysis of GPIIb and GPIIIa cDNA, and platelet mRNA levels for both subunits, were normal. These findings document an acquired combined defect in membrane expression (secondary to a defect in post-translational processing of the complex) and inside-out signalling-dependent activation of the GPIIb-IIIa complex. PMID:11122160

Kaplan, R; Gabbeta, J; Sun, L; Mao, G F; Rao, A K

2000-12-01

355

BRAIN CORTEX Na +–K +ATPase ACTIVITIES IN STREPTOZOTOCIN-DIABETIC AND PENTYLENETETRAZOL-EPILEPTIC RATS  

Microsoft Academic Search

The aim of this study was to investigate the brain cortex Na+–K+ATPase activity in rats made diabetic by streptozotocin and epileptic by pentylenetetrazol. Streptozotocin diabetic rats showed a significant decrease in brain cortex Na+–K+ATPase activity whereas the pentylenetetrazol treatment caused no significant change in enzyme activity. On the other hand, no brain cortex Na+–K+ATPase activity could be detected in all

PERNUR ÖNER; BARIA ÖZTA?; HIKMET KOÇAK

1997-01-01

356

The effects of trypsin on rat brain astrocyte activation  

PubMed Central

Background Astrocytes are cells within the central nervous system which are activated in a wide spectrum of infections, and autoimmune and neurodegenerative diseases. In pathologic states, they produce inflammatory cytokines, chemokines, and nitric oxide (NO), and sometimes they induce apoptosis. Their protease-activated receptors (PARs) can be activated by proteases, e.g. thrombin and trypsin, which are important in brain inflammation. The current study aimed to investigate the effects of different concentrations of trypsin (1 to 100U/ml) on cultured astrocytes. Methods In the present study, two-day rat infants’ brains were isolated and homogenized after meninges removal, then cultivated in DMEM + 10% FBS medium. 10 days later, astrocytes were harvested and recultivated for more purification (up to 95%), using Immunocytochemistry method, in order to be employed for tests. They were affected by different concentrations of trypsin (1, 5, 10, 15, 20, 40, 60, 80, and 100 U/ml). To reveal the inflammation progress, NO concentrations (the Griess test) were assessed after 24 and 48 hours. Results The results showed that trypsin concentration up to 20 U/ml caused a significant increase in NO, in a dose-dependent manner, on cultured astrocytes (P < 0.001). Trypsin 20 U/ml increased NO production fivefold the control group (P < 0.001). At higher concentrations than 20 U/ml, NO production diminished (P < 0.001). At 100 U/ml, NO production was less than the control group (P < 0.001). Conclusion Inflammatory effects of trypsin 5-20 U/ml are probably due to the stimulation of astrocytes’ PAR-2 receptors and the increasing of the activation of NF-?B, PKC, MAPKs. Stimulation of astrocytes’ PAR-2 receptors causes an increase in iNOS activation which in turn leads to NO production. However, higher trypsin concentration possibly made astrocyte apoptosis; therefore, NO production diminished. These assumptions need to be further investigated.

Fereidoni, Masoud; Sabouni, Farzaneh; Moghimi, Ali

2013-01-01

357

Caspase Activation in Fetal Rat Brain Following Experimental Intrauterine Inflammation  

PubMed Central

Intrauterine inflammation has been implicated in developmental brain injuries, including the development of periventricular leukomalacia (PVL) and cerebral palsy (CP). Previous studies in our rat model of intrauterine inflammation demonstrated apoptotic cell death in fetal brains within the first 5 days after lipopolysaccharide (LPS) administration to mothers and eventual dysmyelination. Cysteine-containing, aspartate-specific proteases, or caspases, are proteins involved with apoptosis through both intracellular (intrinsic pathway) and extracellular (extrinsic pathway) mechanisms. We hypothesized that cell death in our model would occur mainly via activation of the extrinsic pathway. We further hypothesized that Fas, a member of the tumor necrosis factor receptor (TNFR) superfamily, would be increased and the death inducing signaling complex (DISC) would be detectable. Pregnant rats were injected intracervically with LPS at E15 and immunoblotting, immunohistochemical and immunoprecipitation analyses were performed. The presence of the activated form of the effector caspase (caspase-3) was observed 24 h after LPS administration. Caspase activity assays demonstrated rapid increases in (i) caspases-9 and -10 within 1 h, (ii) caspase-8 at 2 h and (iii) caspase-3 at 4 h. At 24 h after LPS, activated caspase-3+/Fas+ cells were observed within the developing white matter. Lastly, the DISC complex (caspase-8, Fas and Fas-associated Death Domain (FADD)) was observed within 30 min by immunoprecipitation. Apoptosis in our model occurs via both extrinsic and intrinsic pathways, and activation of Fas may play a role. Understanding the mechanisms of cell death in models of intrauterine inflammation may affect development of future strategies to mitigate these injuries in children.

Sharangpani, Aditi; Takanohashi, Asako; Bell, Michael J.

2009-01-01

358

Glucosylceramide synthase decrease in frontal cortex of Alzheimer brain correlates with abnormal increase in endogenous ceramides: consequences to morphology and viability on enzyme suppression in cultured primary neurons.  

PubMed

Abnormal increase in native long-chain ceramides (lcCer) in AD implicates roles in neuronal atrophy and cognitive dysfunction especially in view of divergent roles this second messenger plays in cell function. Since clearance is mediated by glucosylceramide synthase (GCS, EC 2.4.1.80) levels of the enzyme were compared for 18 samples of AD Brodmann area 9/10 frontal cortex with 11 age-matched controls. Western analysis for (ir)GCS showed a significant decrease in AD brain (p<0.01) consistent with the hypothesis that enzyme dysfunction contributes to neuronal decay. To examine kinetics and consequences to morphology, cerebellar granule cells were treated in vitro with d-threo-P4 (P4). This potent inhibitor of GCS induced a time- and concentration-dependent increase in lcCer parallel to loss of viability and dramatic changes in neuron/neurite morphology via caspase-independent pathways distinct from those of apoptosis or necrosis. Fluorescent labeling with NBD-sphingolipids or immunostaining with anti-synaptic or cytoskeletal markers showed unusual formation of globular swellings along neurites rich in synaptophysin that may resemble formation of dystrophic neurites in AD. Effects of the inhibitor were verified by changes in lcCer mass and turnover of (14)[C]-acetate and -galactose or NBD-labeled anabolic products. Addition of a panel of inhibitors of other pathways confirms GCS as the major route for clearance in the present model. Pretreatment with GM(1) whose turnover is compromised was protective and pointed to useful therapeutic applications by supplementing existing membrane stores prior to GSC dysfunction. PMID:18155680

Marks, Neville; Berg, Martin J; Saito, Mariko; Saito, Mitsuo

2008-01-29

359

The separation of bovine brain beta-N-acetyl-D-hexosaminidases. Abnormal gel-filtration behaviour of beta-N-acetyl-D-glucosaminidase C.  

PubMed Central

Bovine brain tissue was extracted and the 50 000g supernatant was separated by electrophoresis, DEAE-Sephadex chromatography and gel filtration on Sephadex G-200 and Bio-Gel P-200. The electrophoretic separation showed that the beta-N-acetyl-D-hexosaminidases (hexosaminidases) of bovine brain tissue were composed of four different fractions. Two fractions (A and B) exerted both glucosaminidase and galactosaminidase activity, a third fraction (C) showed only glucosaminidase activity, whereas a fourth form (D) with specificity towards the galactosaminide moiety was found to be present. DEAE-Sephadex chromatography at pH 7.0 showed that the B form was eluted with the void volume, whereas the A and D forms could be eluted in one peak by raising that salt concentration. The C form could not be detected in the eluate. Gel filtration on Sephadex G-200 showed that the B, A and D forms had almost equal molecular weights. In this case also the C form could not be detected in the column eluates. Gel filtration on Bio-Gel P-200 revealed that the C form was eluted with the void volume.

Overdijk, B; van der Kroef, W M; Veltkamp, W A; Hooghwinkel, G J

1975-01-01

360

Brain stem reticular formation and activation of the EEG.  

PubMed

1. Stimulation of the reticular formation of the brain stem evokes changes in the EEG, consisting of abolition of synchronized discharge and introduction of low voltage fast activity in its place, which are not mediated by any of the known ascending or descending paths that traverse the brain stem. The alteration is a generalized one but is most pronounced in the ipsilateral hemisphere and, sometimes, in its anterior part. 2. This response can elicited by stimulating the medical bulbar reticular formation, pontile and midbrain tegmentum, and dorsal hypothalamus and subthalamus. The bulbar effect is due to ascending impulses relayed through these more cephalic structures. The excitable substrate possesses a low threshold and responds best to high frequencies of stimulation. 3. Some background synchrony of electrocortical activity is requisite for manifestation of the response. In the "encephale isolé", reticular stimulation has no additional effect upon the fully activated EEG. With synchrony, in spontaneous drowsiness or light chloralosane anesthesia, the effect of reticular stimulation is strikingly like Berger's alpha wave blockade, or any arousal reaction. In full chloralosane anesthesia, high voltage slow waves are blocked but no increase in lower amplitude, fast activity occurs. With barbiturate anesthesia, the reticular response is difficult to elicit or is abolished. 4. In the chloralosane preparation, the secondary cortical response evoked by a sensory volley is generally unaffected by reticular stimulation. Consequent sensory after-discharge is abolished, however, as is pyramidal tract discharge and jerky movements referable to it. Outside the sensory receiving area, secondary responses themselves may be reduced or prevented. 5. The convulsive spikes produced by local strychnine and those of a fit following supramaximal cortical excitation, are not decreased by stimulating the reticular formation. 6. The cortical recruiting response induced by low frequency stimulation of the diffuse thalamic projection system is reduced or abolished by reticular stimulation. 7. There is some indication that the cortical effect of reticular stimulation may be mediated by this diffuse thalamic projection system, for synchronized activity within it is similarly prevented by reticular excitation, and direct high frequency stimulation of this system, within the thalamus, reproduces the reticular response. It is possible, however, that other mechanisms may be involved in its mediation. 8. The reticular response and the arousal reaction to natural stimuli have been compared in the "encéphale isolé", in which EEG synchrony was present during spontaneous relaxation or was produced by recruiting mechanisms, and the two appear identical. 9. The possibility that the cortical arousal reaction to natural stimuli is mediated by collaterals of afferent pathways to the brain stem reticular formation, and thence through the ascending reticular activating system, rather than by intra-cortical spread following the arrival of afferent impulses at the sensory receiving areas of the cortex, is under investigation. 10. The possibility is considered that a background of maintained activity within this ascending brain stem activating system may account for wakefulness, while reduction of its activity either naturally, by barbiturates, or by experimental injury and disease, may respectively precipitate normal sleep, contribute to anesthesia or produce pathological somnolence. PMID:18421835

Moruzzi, G; Magoun, H W

1949-11-01

361

Topography of brain electrical activity: a bioengineering approach.  

PubMed

The aim of this work is to describe a system for the mono- and bi-dimensional analysis of brain electrical activity. The analysis was carried on either by visual inspection of mono- and bi-dimensional data, or by automatic feature extraction from the bidimensional data. Because of the importance of visual inspection for the analysis of experimental data, particular care was devoted to optimize the displayed data perceptually. For automatic screening of large amounts of data (and to allow long term studies of clinical records), statistical facilities were also provided. One purpose of the system was to develop image processing algorithms oriented toward biomedical images, that could be easily implemented on special purpose, low cost hardware, like VLSI or microcomputer arrays. This was possible because of the modularity of the larger part of bidimensional processing, such as interpolation and statistical analysis. Results of an experiment on Visual Evoked Response are presented, showing that through abidimensional analysis of the recorded data the resolution achievable in the localization of brain electrical activity can be increased to less than 1 cm. PMID:6669147

Sandini, G; Romano, P; Scotto, A; Traverso, G

1983-01-01

362

Imaging of human brain creatine kinase activity in vivo.  

PubMed

Creatine kinase activity and high-energy phosphate concentration have been investigated using localized 31P spectroscopy in the human brain in vivo. The phase-modulated rotating frame imaging technique, incorporating magnetization transfer and inversion recovery, has been used to produce a 1-dimensional rate profile map of steady-state enzyme activity. Large differences in the flux from phosphocreatine (PCr) to ATP have been discovered between volumes of human brain consisting of predominantly gray (2.0 cm) and white (4.5 cm) matter. The concentration of PCr changes slightly (2.0 cm = 5.20 +/- 0.45 mmol.l-1, 4.5 cm = 4.63 +/- 0.31 mmol.l-1), while the ATP concentration remains within limits (3.30 +/- 0.4 mmol.l-1). No change in pHi was detected between the two regions in normal volunteers (n = 6). The forward rate constant of the PCr----ATP reaction in regions of predominantly gray matter (0.30 +/- 0.04 s-1) was twice that of white matter (0.16 +/- 0.02 s-1) in vivo. PMID:2629743

Cadoux-Hudson, T A; Blackledge, M J; Radda, G K

1989-12-01

363

Immunocytochemical evaluation of proliferative activity in human brain tumours.  

PubMed

The immunocytochemical expression of the antigen reacting with the monoclonal antibody Ki-67 (Ki-67 positivity) was investigated in 50 imprint preparations from human brain tumours. Data were related to tumour proliferative activity, as determined from in vivo bromodeoxyuridine (BrdU) incorporation (BrdU-labelling index, BrdU-LI) and histology. The percentage of Ki-67-positive cells was greater than the corresponding BrdU-LI value in all tumours, and the differences in Ki-67 positivity among tumour subtypes paralleled the BrdU-LI differences. Both the BrdU-LI and the percentage of Ki-67 positive cells were significantly greater (P less than 0.005) in the group of clinically aggressive adult tumours, histologically identified as anaplastic astrocytomas and glioblastomas, than in the less aggressive ones (oligodendroglioma, meningiomas, schwannomas, pituitary adenomas, dermoid cyst) and in the cerebral metastatic localizations. These data suggest that Ki-67 positivity, which is easily evaluated with immunocytochemistry, is related to the proliferative activity of brain tumours and that this parameter is endowed with clinical significance. PMID:2275874

Girino, M; Riccardi, A; Danova, M; Gaetani, P; Butti, G; Giordano, M; Cuomo, A

1990-09-01

364