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To modulate or not to modulate: Differing results in uniquely shaped Williams syndrome brains

NEUROimage 2006年第3期32卷 1001-1007页

作者： Eckert, Mark A. Tenforde, Adam Galaburda, Albert M. Bellugi, Ursula Korenberg, Julie R. Mills, Debra Reiss, Allan L. Med Univ S Carolina Dept Otolaryngol Head & Neck Surg Charleston SC 29425 USA Stanford Univ Sch Med Dept Psychiat & Behav Sci Stanford CA 94305 USA Harvard Univ Sch Med Dept Neurol Cambridge MA 02138 USA Univ Calif Los Angeles Dept Pediat Los Angeles CA 90024 USA Emory Univ Dept Psychol Atlanta GA 30322 USA

Voxel based morphometry (VBM) studies of Williams syndrome (WS) have demonstrated remarkably consistent findings of reduced posterior parietal gray matter compared to typical controls. Other WS VBM findings have been inconsistent, however. In particular, different findings have been reported for hypothalamus and orbitofrontal gray matter regions. We examined a sample of 8 WS and 9 control adults and show that the hypothalamus and orbitofrontal cortex results depend on whether the images undergo Jacobian modulation. Deformation based morphometry (DBM) analysis demonstrated that major brain shape differences between the groups accounted for the Jacobian modulated gray matter findings. These results indicate that cautious interpretations of modulated gray matter findings are warranted when there are gross shape and size differences between experimental groups. This study demonstrates the importance of methodological choices towards understanding a disorder like WS, but also highlights the consistency of parietal lobe, orbitofrontal, and midbrain findings for this disorder across methodologies, participants, and research groups. (c) 2006 Elsevier Inc. All rights reserved.

关键词： Adult Brain/pathology Female Frontal Lobe/pathology Functional Laterality/physiology Humans Hypothalamus/pathology image processing, computer-assisted Magnetic Resonance Imaging Male Mesencephalon/pathology Orbit/pathology Parietal Lobe/pathology Signal Transduction/physiology Williams Syndrome/pathology

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Mapping radiation dose distribution on the fractional anisotropy map: Applications in the assessment of treatment-induced white matter injury

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NEUROimage 2006年第1期31卷 109-115页

作者： Qiu, Deqiang T Leung, Lucullus H. Kwong, Dora L. W. Chan, Godfrey C. F. Khong, Pek-Lan Univ Hong Kong Queen Mary Hosp Dept Diagnost Radiol Hong Kong Hong Kong Peoples R China Univ Hong Kong Queen Mary Hosp Dept Clin Oncol Hong Kong Hong Kong Peoples R China Univ Hong Kong Queen Mary Hosp Dept Pediat & Adolescent Med Hong Kong Hong Kong Peoples R China

We describe a method to map whole brain radiation dose distribution on to diffusion tensor MR (DT-MR) fractional anisotropy (FA) images and illustrate its applications for studying dose-effect relationships and regional susceptibility in two childhood medulloblastoma survivors. To determine the FA changes voxel-by-voxel in white matter, the post-treatment follow-up FA maps were coregistered to baseline pretreatment FA maps and automatic segmentation for white matter was carried out. Delta FA maps representing relative FA change in white matter were hence generated for visual inspection and quantitative analysis. The radiation dose distribution, calculated from radiotherapy plan and exported as images, was coregistered to baseline FA images. DT-MR imaging and processing noise was small with root mean square value of 1.49% for mean Delta FA. We evaluated the mean Delta FA changes of regions-of-interest according to radiation dose regions to provide an estimate of the dose-response and found increasing reduction in mean Delta FA with increasing radiation dose up to 45 Gy after which there was a reversal in the mean FA trend and mean FA approached baseline value. We also found more severe mean FA reduction in the frontal lobes compared to the parietal lobes despite the same radiation dose, suggesting regional susceptibility in the frontal lobe, and mean FA increase in the brainstem after radiation in both patients. We conclude that the method described may be useful in estimating dose-effect relationships and studying regional susceptibility of the brain to radiation in medulloblastoma survivors. (c) 2005 Elsevier Inc. All rights reserved.

关键词： Anisotropy Brain/radiation effects Brain Mapping Brain Mapping Brain Stem/radiation effects Cerebellar Neoplasms/drug therapy Cerebellar Neoplasms/radiotherapy Cerebellar Neoplasms/surgery Child Combined Modality Therapy Cranial Irradiation Diffusion Magnetic Resonance Imaging Dose-Response Relationship, Radiation Dose-Response Relationship, Radiation Female Frontal Lobe/radiation effects Humans image processing, computer-assisted Male Medulloblastoma/drug therapy Medulloblastoma/radiotherapy Medulloblastoma/surgery Parietal Lobe/radiation effects Radiation Injuries/diagnosis Radiation Injuries/diagnosis Radiotherapy Dosage Radiotherapy, Adjuvant Reference Values Sensitivity and Specificity Survivors

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Perception of matching and conflicting audiovisual speech in dyslexic and fluent readers:: An fMRI study at 3 T

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NEUROimage 2006年第3期29卷 797-807页

作者： Pekkola, J Laasonen, M Ojanen, V Autti, T Jääskelainen, IP Kujala, T Sams, M Univ Helsinki Cent Hosp Dept Radiol Helsinki Med Imaging Ctr FIN-00029 Helsinki Finland Aalto Univ Inst Computat Engn FIN-02150 Espoo Finland Aalto Univ Adv Magnet Imaging Ctr FIN-02150 Espoo Finland Univ Helsinki Dept Psychol SF-00100 Helsinki Finland Univ Helsinki Cent Hosp Phoniatr Dept FIN-00029 Helsinki Finland Univ Helsinki Helsinki Coll Adv Studies FIN-00029 Helsinki Finland Univ Helsinki Dept Psychol Cognit Brain Res Unit FIN-00029 Helsinki Finland Helsinki Brain Res Ctr Helsinki Finland

We presented phonetically matching and conflicting audiovisual vowels to 10 dyslexic and 10 fluent-reading young adults during "clustered volume acquisition" functional magnetic resonance imaging (fMRI) at 3 T. We further assessed co-variation between the dyslexic readers' phonological processing abilities, as indexed by neuropsychological test scores, and BOLD signal change within the visual cortex, auditory cortex, and Brocals area. Both dyslexic and fluent readers showed increased activation during observation of phonetically conflicting compared to matching vowels within the classical motor speech regions (Broca's area and the left premotor cortex), this activation difference being more extensive and bilateral in the dyslexic group. The between-group activation difference in conflicting > matching contrast reached significance in the motor speech regions and in the left inferior parietal lobule, with dyslexic readers exhibiting stronger activation than fluent readers. The dyslexic readers' BOLD signal change co-varied with their phonological processing abilities within the visual cortex and Broca's area, and to a lesser extent within the auditory cortex. We suggest these findings as reflecting dyslexic readers' greater use of motor-articulatory and visual strategies during phonetic processing of audiovisual speech, possibly to compensate for their difficulties in auditory speech perception. (c) 2005 Elsevier Inc. All rights reserved.

关键词： Acoustic Stimulation Adult Auditory Cortex/physiology Data Interpretation, Statistical Dyslexia/physiopathology Dyslexia/psychology Female Frontal Lobe/physiology Humans image processing, computer-assisted Intelligence Tests Magnetic Resonance Imaging Male Neuropsychological Tests Oxygen/blood Photic Stimulation Prefrontal Cortex/physiology Reading Speech Perception/physiology Visual Cortex/physiology Visual Perception/physiology

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An fMRI study of the motor system in patients with neuropsychiatric systemic lupus erythematosus

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NEUROimage 2006年第2期30卷 478-484页

作者： Rocca, MA Agosta, F Mezzapesa, DM Ciboddo, G Falini, A Comi, G Filippi, M Sci Inst Milan Dept Neurol Neuroimaging Res Unit I-20132 Milan Italy Univ Osped San Raffaele Milan Italy Sci Inst Milan Dept Neurol Milan Italy Sci Inst Milan Dept Med Milan Italy Sci Inst Milan Dept Neuroradiol Milan Italy

Functional cortical changes have been demonstrated in patients with several neurological conditions, including stroke, tumors and MS. The correlation found between the extent of fMRI activations and the extent and severity of brain structural damage suggests an adaptive role of these functional changes. In this study, we assess, using fMRI, the brain pattern of movement-associated cortical activations in neuropsychiatric systemic lupus erythematosus (NPSLE) patients and investigate whether the extent of cortical reorganization is associated with the extent of brain pathology, measured on dual-echo and diffusion tensor (DT) MR images. From 14 right-handed NPSLE patients and 14 matched controls, we obtained: (a) fMRI during the performance of repetitive flexion-extension of the last four fingers of the right hand;(b) dual-echo and (c) pulsed-gradient spin-echo echo-planar sequence to calculate DT MRI maps of the normal-appearing white (NAWM) and gray (NAGM) matter. Brain T2-visible abnormalities were detected in I I NPSLE patients. Compared with controls, NPSLE patients had significantly higher NAWM fractional anisotropy histogram peak height (P = 0.005), and more significant activations of the contralateral primary sensorimotor cortex, putamen and dentate nucleus. They also had more significant activations of several regions located in the frontal and parietal lobes as well as of MT/V5 and the middle occipital gyrus, bilaterally. Strong correlations (r values ranging from 0.79 to 0.87) were found between relative activations of sensorimotor areas and the extent and severity of brain damage. Movement-associated functional cortical changes do occur in patients with NPSLE and might contribute to the maintenance of their normal functional capacities. (c) 2005 Elsevier Inc. All rights reserved.

关键词： Adult Aged Brain Ischemia/pathology Cluster Analysis Efferent Pathways/physiology Female Humans image processing, computer-assisted Lupus Erythematosus, Systemic/complications Lupus Erythematosus, Systemic/pathology Lupus Erythematosus, Systemic/psychology Magnetic Resonance Imaging Male Mental Disorders/etiology Mental Disorders/psychology Middle Aged Motor Cortex/physiology Oxygen/blood

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Perirhinal cortex activity during visual object discrimination: An event-related fMR1 study

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NEUROimage 2006年第1期33卷 362-373页

作者： Lee, Andy C. H. Bandelow, Stephan Schwarzbauer, Christian Henson, Richard N. A. Graham, Kim S. MRC Cognit & Brain Sci Unit Cambridge CB2 2EF England

Previous fMRI studies have demonstrated preferential involvement of the perirhinal cortex and hippocampus in tasks of object and spatial memory, respectively. Here we investigated whether similar activity would also be present when object and spatial discrimination was assessed in the absence of explicit declarative memory demands. On each trial in the scanner, participants were presented simultaneously with two arrays of objects and were asked to indicate whether both arrays were identical, differed with respect to the identity of one object or differed with respect to the spatial arrangement of the objects. It was found that the detection of an object identity change was associated with significant right perirhinal cortex activity. We suggest that this perirhinal activity indicates a role of this structure in processes beyond., for example, short-term visual working memory declarative memory or higher order perception. Significantly greater hippocampal activity was not, however, observed during the spatial arrangement condition, perhaps due to the relatively low spatial processing demands of this task. (c) 2006 Elsevier Inc. All rights reserved.

关键词： Adolescent Adult Discrimination (Psychology)/physiology Female Hippocampus/physiology Humans image processing, computer-assisted Magnetic Resonance Imaging Male Oxygen/blood Photic Stimulation Visual Perception/physiology

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Impact of language proficiency and orthographic transparency on bilingual word reading: An fMRI investigation

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NEUROimage 2006年第4期29卷 1135-1140页

作者： Meschyan, G Hemandez, AE Univ Houston Dept Psychol Houston TX 77204 USA

The purpose of the present functional magnetic resonance imaging (fMRI) investigation was to examine how language proficiency and orthographic transparency (letter-sound mapping consistency) modulate neural activity during bilingual single word reading. Spanish-English bilingual participants, more fluent in their second language (L2;English) than their native language (L1;Spanish), were asked to read words in the two languages. Behavioral results showed that participants were significantly slower in reading words in their less proficient language (Spanish) than in their more proficient language (English). fMRI results also revealed that reading words in the less proficient language yielded greater activity in the articulatory motor system, consisting of supplementary motor area/cingulate, insula, and putamen. Together, the behavioral and fMRI results suggest that the less practiced, hence less proficient, language requires greater articulatory motor effort, which results in slower reading rates. Moreover, we found that orthographic transparency also played a neuromodulatory role. More transparent Spanish words yielded greater activity in superior temporal gyrus (STG;BA 22), a region implicated in phonological processing, and orthographically opaque English words yielded greater activity in visual processing and word recoding regions, such as the occipito-parietal border and inferior parietal lobe (IPL;BA 40). Overall, our fMRI results suggest that the articulatory motor system is more plastic, hence, more amenable to change because of greater exposure to the L2. By contrast, we propose that our orthography effect is less plastic, hence, less influenced by frequency of exposure to a language system. (c) 2005 Elsevier Inc. All rights reserved.

关键词： Adult Brain Mapping Brain Mapping Female Humans image processing, computer-assisted Magnetic Resonance Imaging Male Multilingualism Neuronal Plasticity/physiology Phonetics Practice (Psychology) Reaction Time/physiology Reading Writing

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Neural recruitment associated with anomia treatment in aphasia

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NEUROimage 2006年第3期32卷 1403-1412页

作者： Fridriksson, Julius Morrow-Odom, Leigh Moser, Dana Fridriksson, Astrid Baylis, Gordon Univ S Carolina Dept Commun Sci & Disorders Columbia SC 29208 USA Univ S Carolina Dept Psychol Columbia SC 29208 USA

The purpose of this study was to investigate changes in the spatial distribution of cortical activity associated with anomia treatment in three persons with aphasia. Participants underwent three fMRI sessions before and after a period of intensive language treatment focused on object naming. The results revealed bilateral hemispheric recruitment associated with improved ability to name items targeted in treatment. This is the first study to employ multiple pre- and post-treatment fMRI sessions in the study of treatment-induced recovery from aphasia and has implications for future studies of brain plasticity in stroke. (c) 2006 Elsevier Inc. All rights reserved.

关键词： Aged Anomia/pathology Anomia/physiopathology Anomia/therapy Auditory Perception/physiology Brain Mapping Brain Mapping Cerebral Cortex/pathology Cerebral Cortex/physiopathology Data Interpretation, Statistical Humans image processing, computer-assisted Language Therapy Magnetic Resonance Imaging Male Middle Aged Neural Pathways/pathology Neuronal Plasticity/physiology Psychomotor Performance/physiology Recruitment, Neurophysiological/physiology Stroke/physiopathology Stroke/psychology Verbal Behavior Visual Perception/physiology

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AMPAR removal underlies Aβ-induced synaptic depression and dendritic spine loss

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NEURON 2006年第5期52卷 831-843页

作者： Hsieh, Helen Boehm, Jannic Sato, Chihiro Iwatsubo, Takeshi Tomita, Taisuke Sisodia, Sangram Malinow, Roberto Cold Spring Harbor Lab Cold Spring Harbor NY 11724 USA SUNY Stony Brook Dept Neurobiol Stony Brook NY 11794 USA SUNY Stony Brook Behav Grad Program Stony Brook NY 11794 USA Univ Tokyo Dept Neuropathol & Neurosci Grad Sch Pharmaceut Sci Tokyo Japan Univ Chicago Ctr Mol Neurobiol Dept Neurobiol Pharmacol & Physiol Chicago IL 60637 USA

Beta amyloid (A beta), a peptide generated from the amyloid precursor protein (APP) by neurons, is widely believed to underlie the pathophysiology of Alzheimer's disease. Recent studies indicate that this peptide can drive loss of surface AMPA and NMDA type glutamate receptors. We now show that A beta employs signaling pathways of long-term depression (LTD) to drive endocytosis of synaptic AMPA receptors. Synaptic removal of AMPA receptors is necessary and sufficient to produce loss of dendritic spines and synaptic NIVIDA responses. Our studies indicate the central role played by AMPA receptor trafficking in A beta-induced modification of synaptic structure and function.

关键词： Alphavirus Infections/genetics Amyloid beta-Protein/physiology Animals Cells, Cultured Dendritic Spines/drug effects Dendritic Spines/physiology Dendritic Spines/ultrastructure DNA/biosynthesis DNA/genetics Electrophysiology Endocytosis/genetics Endocytosis/physiology Enzyme-Linked Immunosorbent Assay Enzyme-Linked Immunosorbent Assay Excitatory Amino Acid Antagonists/pharmacology Excitatory Postsynaptic Potentials/drug effects image processing, computer-assisted Immunoblotting Immunoblotting Mutation/physiology Neuronal Plasticity/drug effects Neuronal Plasticity/physiology Neurons/physiology Neurons/ultrastructure p38 Mitogen-Activated Protein Kinases/genetics p38 Mitogen-Activated Protein Kinases/physiology Patch-Clamp Techniques Patch-Clamp Techniques Phosphorylation Rats Receptors, AMPA/drug effects Receptors, AMPA/drug effects Receptors, AMPA/genetics Receptors, AMPA/genetics Receptors, AMPA/physiology Receptors, AMPA/physiology Receptors, Metabotropic Glutamate/biosynthesis Receptors, Metabotropic Glutamate/genetics Sindbis Virus/genetics Synapses/drug effects Synapses/physiology Synapses/ultrastructure Transfection

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Neuroanatomical dissociation between bottom-up and top-down processes of visuospatial selective attention

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NEUROimage 2006年第2期32卷 842-853页

作者： Hahn, Britta Ross, Thomas J. Stein, Elliot A. NIDA Intramural Res Program Neuroimaging Res Branch NIH Baltimore MD 21224 USA

Allocation of attentional resources to portions of the available sensory input can be regulated by bottom-up processes, i.e., spontaneous orientation towards an oncoming stimulus (stimulus-driven attention), and by top-down processes, i.e., intentionally and driven by knowledge, expectation and goals. The present study aimed at advancing the understanding of brain networks mediating bottom-up and top-down control of visuospatial attention by employing a paradigm that parametrically varied demands on these two processes. Spatial predictability of peripheral targets was parametrically varied by centrally cueing one, two, three or four of four possible locations. Reaction time decreased linearly with more precise valid cueing of the target location and increased with more precise invalid cueing. Event-related functional magnetic resonance imaging (fMRI) enabled measurement of blood oxygenation level-dependent (BOLD) responses to cues and to targets. A mostly left-hemispheric network consisting of left intraparietal sulcus, inferior and superior parietal lobule, bilateral precuneus, middle frontal gyri including superior frontal sulci, and middle occipital gyri displayed BOLD responses to cues that increased linearly with more precise spatial cueing, indicating engagement by top-down spatial selective attention. In contrast, bilateral temporoparietal junction, cingulate gyrus, right precentral gyrus and anterior and posterior insula, bilateral fusiform gyri, lingual gyri and caucus displayed BOLD responses to targets that increased with their spatial unpredictability, indicating engagement by stimulus-driven orienting. The results suggest two largely dissociated neural networks mediating top - down and bottom - up control of visuospatial selective attention. (c) 2006 Elsevier Inc. All rights reserved.

关键词： Adult Attention/physiology Brain Mapping Brain Mapping Cues Dominance, Cerebral/physiology Female Humans image processing, computer-assisted Imaging, Three-Dimensional Magnetic Resonance Imaging Male Nerve Net/physiology Orientation/physiology Oxygen/blood Pattern Recognition, Visual/physiology

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Multiple brain networks for visual self-recognition with different sensitivity for motion and body part

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NEUROimage 2006年第4期32卷 1905-1917页

作者： Sugiura, Motoaki Sassa, Yuko jeong, Hyeon Jeong Miura, Naoki Akitsuki, Yuko Horie, Kaoru Sato, Shigeru Kawashima, Ryuta Miyagi Univ Educ Aoba Ku Sendai Miyagi 9800845 Japan Tohoku Univ NICHe Sendai Miyagi 980 Japan JST RISTEX Kawaguchi Japan Tohoku Univ GSICS Sendai Miyagi 980 Japan JST CREST Kawaguchi Japan Tohoku Univ Dept Psychiat Grad Sch Med Sendai Miyagi 980 Japan Tohoku Univ LBC Res Ctr Sendai Miyagi 980 Japan

Multiple brain networks may support visual self-recognition. It has been hypothesized that the left ventral occipito-temporal cortex processes one's own face as a symbol, and the right parieto-frontal network processes self-image in association with motion-action contingency. Using functional magnetic resonance imaging, we first tested these hypotheses based on the prediction that these networks preferentially respond to a static self-face and to moving one's whole body, respectively. Brain activation specifically related to self-image during familiarity judgment was compared across four stimulus conditions comprising a two factorial design: factor Motion contrasted picture (Picture) and movie (Movie), and factor Body part a face (Face) and whole body (Body). Second, we attempted to segregate self-specific networks using a principal component analysis (PCA), assuming an independent pattern of inter-subject variability in activation over the four stimulus conditions in each network. The bilateral ventral occipito-temporal and the right parietal and frontal cortices exhibited self-specific activation. The left ventral occipito-temporal cortex exhibited greater self-specific activation for Face than for Body, in Picture, consistent with the prediction for this region. The activation profiles of the right parietal and frontal cortices did not show preference for Movie Body predicted by the assumed roles of these regions. The PCA extracted two cortical networks, one with its peaks in the right posterior, and another in frontal cortices;their possible roles in visuo-spatial and conceptual self-representations, respectively, were suggested by previous findings. The results thus supported and provided evidence of multiple brain networks for visual self-recognition. (c) 2006 Elsevier Inc. All rights reserved.

关键词： Adolescent Adult Brain/physiology Cerebral Cortex/physiology Female Functional Laterality/physiology Humans image processing, computer-assisted Individuality Magnetic Resonance Imaging Male Motion Perception/physiology Nerve Net/physiology Photic Stimulation Principal Component Analysis Reaction Time/physiology Recognition (Psychology)/physiology Self Concept

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