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https://www.readbyqxmd.com/read/27921067/parallel-pathways-from-whisker-and-visual-sensory-cortices-to-distinct-frontal-regions-of-mouse-neocortex
#1
Varun Sreenivasan, Alexandros Kyriakatos, Celine Mateo, Dieter Jaeger, Carl C H Petersen
The spatial organization of mouse frontal cortex is poorly understood. Here, we used voltage-sensitive dye to image electrical activity in the dorsal cortex of awake head-restrained mice. Whisker-deflection evoked the earliest sensory response in a localized region of primary somatosensory cortex and visual stimulation evoked the earliest responses in a localized region of primary visual cortex. Over the next milliseconds, the initial sensory response spread within the respective primary sensory cortex and into the surrounding higher order sensory cortices...
July 2017: Neurophotonics
https://www.readbyqxmd.com/read/27920873/migratory-stroke-like-lesions-in-a-case-of-adult-onset-mitochondrial-encephalomyopathy-lactic-acidosis-and-stroke-like-episodes-melas-syndrome-and-a-review-of-imaging-findings
#2
Stephen S Cai, Rainer von Coelln, Theresa J Kouo
Imaging findings of adult-onset mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes (MELAS) syndrome is poorly documented. The authors present a 48-year-old woman with subacute onset of word-finding difficulties and right arm stiffness. Magnetic resonance imaging performed 2 weeks prior revealed left temporal lobe diffusion and fluid-attenuated inversion recovery hyperintensity predominantly involving the cortex. The apparent diffusion coefficient map showed preserved signal in the temporal cortex...
December 2016: Radiology case reports
https://www.readbyqxmd.com/read/27920794/dance-experience-and-associations-with-cortical-gray-matter-thickness-in-the-aging-population
#3
Shai Porat, Naira Goukasian, Kristy S Hwang, Theodore Zanto, Triet Do, Jonathan Pierce, Shantanu Joshi, Ellen Woo, Liana G Apostolova
INTRODUCTION: We investigated the effect dance experience may have on cortical gray matter thickness and cognitive performance in elderly participants with and without mild cognitive impairment (MCI). METHODS: 39 cognitively normal and 48 MCI elderly participants completed a questionnaire regarding their lifetime experience with music, dance, and song. Participants identified themselves as either dancers or nondancers. All participants received structural 1.5-tesla MRI scans and detailed clinical and neuropsychological evaluations...
September 2016: Dementia and Geriatric Cognitive Disorders Extra
https://www.readbyqxmd.com/read/27920431/cerebral-blood-flow-blood-supply-and-cognition-in-type-2-diabetes-mellitus
#4
Jacobus F A Jansen, Frank C G van Bussel, Harm J van de Haar, Matthias J P van Osch, Paul A M Hofman, Martin P J van Boxtel, Robert J van Oostenbrugge, Miranda T Schram, Coen D A Stehouwer, Joachim E Wildberger, Walter H Backes
We investigated whether type 2 diabetes (T2DM) and the presence of cognitive impairment are associated with altered cerebral blood flow (CBF). Forty-one participants with and thirty-nine without T2DM underwent 3-Tesla MRI, including a quantitative technique measuring (macrovascular) blood flow in the internal carotid artery and an arterial spin labeling technique measuring (microvascular) perfusion in the grey matter (GM). Three analysis methods were used to quantify the CBF: a region of interest analysis, a voxel-based statistical parametric mapping technique, and a 'distributed deviating voxels' method...
December 2016: Scientific Reports
https://www.readbyqxmd.com/read/27920095/functional-characterization-of-the-left-ventrolateral-premotor-cortex-in-humans-a-direct-electrophysiological-approach
#5
L Fornia, V Ferpozzi, M Montagna, M Rossi, M Riva, F Pessina, F Martinelli Boneschi, P Borroni, R N Lemon, L Bello, G Cerri
In monkeys, motor outputs from premotor cortex (PM) involve cortico-cortical connections with primary motor cortex (M1). However, in humans, the functional organization of PM and its relationship with the corticospinal tract (CST) is still uncertain. This study was carried out in 21 patients undergoing intraoperative brain mapping prior to tumor resection. The left ventrolateral premotor cortex (vlPM-BA6) was identified preoperatively by functional magnetic resonance imaging, and then investigated intraoperatively using high frequency direct electrical stimulation (HF-DES) of the convexity of M1 and vlPM-BA6, with simultaneous recording of motor-evoked potentials (MEPs) from oro-facial, hand and arm muscles...
December 5, 2016: Cerebral Cortex
https://www.readbyqxmd.com/read/27917112/reproducibility-and-reliability-of-quantitative-and-weighted-t1-and-t2-%C3%A2-mapping-for-myelin-based-cortical-parcellation-at-7-tesla
#6
Roy A M Haast, Dimo Ivanov, Elia Formisano, Kâmil Uludaǧ
Different magnetic resonance (MR) parameters, such as R1 (=1/T1) or T2(∗), have been used to visualize non-invasively the myelin distribution across the cortical sheet. Myelin contrast is consistently enhanced in the primary sensory and some higher order cortical areas (such as MT or the cingulate cortex), which renders it suitable for subject-specific anatomical cortical parcellation. However, no systematic comparison has been performed between the previously proposed MR parameters, i.e., the longitudinal and transversal relaxation values (or their ratios), for myelin mapping at 7 Tesla...
2016: Frontiers in Neuroanatomy
https://www.readbyqxmd.com/read/27916888/a-topographical-atlas-of-shiga-toxin-2e-receptor-distribution-in-the-tissues-of-weaned-piglets
#7
Daniel Steil, Robert Bonse, Iris Meisen, Gottfried Pohlentz, German Vallejo, Helge Karch, Johannes Müthing
Shiga toxin (Stx) 2e of Stx-producing Escherichia coli (STEC) is the primary virulence factor in the development of pig edema disease shortly after weaning. Stx2e binds to the globo-series glycosphingolipids (GSLs) globotriaosylceramide (Gb3Cer, Galα1-4Galβ1-4Glcβ1-1Cer) and globotetraosylceramide (Gb4Cer, GalNAcβ1-3Galα1-4Galβ1-4Glcβ1-1Cer), the latter acting as the preferential Stx2e receptor. We determined Stx receptor profiles of 25 different tissues of a male and a female weaned piglet using immunochemical solid phase binding assays combined with mass spectrometry...
November 30, 2016: Toxins
https://www.readbyqxmd.com/read/27915027/tonotopic-representation-of-loudness-in-the-human-cortex
#8
Andrew Thwaites, Josef Schlittenlacher, Ian Nimmo-Smith, William D Marslen-Wilson, Brian C J Moore
A prominent feature of the auditory system is that neurons show tuning to audio frequency; each neuron has a characteristic frequency (CF) to which it is most sensitive. Furthermore, there is an orderly mapping of CF to position, which is called tonotopic organization and which is observed at many levels of the auditory system. In a previous study (Thwaites et al., 2016) we examined cortical entrainment to two auditory transforms predicted by a model of loudness, instantaneous loudness and short-term loudness, using speech as the input signal...
November 30, 2016: Hearing Research
https://www.readbyqxmd.com/read/27914952/independent-tonotopy-and-thalamocortical-projection-patterns-in-two-adjacent-parts-of-the-classical-primary-auditory-cortex-in-mice
#9
Hiroaki Tsukano, Masao Horie, Kuniyuki Takahashi, Ryuichi Hishida, Hirohide Takebayashi, Katsuei Shibuki
Amid recent amendment of delineation of a mouse auditory cortical map, a caudal auditory field, originally defined as the primary auditory cortex (AI), was divided into the AI and dorsomedial field (DM), based on distinct high frequency areas. A low frequency area was not previously established in the DM because responses to low frequency tones were weak in this area. This may lead to the misconception that the DM is an atypical region that lacks a low frequency band. In the current study, we confirmed that the DM has a low frequency area that is completely independent from the AI...
November 30, 2016: Neuroscience Letters
https://www.readbyqxmd.com/read/27913336/local-spectral-analysis-of-the-cerebral-cortex-new-gyrification-indices
#10
Hamed Rabiei, Frederic Richard, Olivier Coulon, Julien Lefevre
Gyrification index (GI) is an appropriate measure to quantify the complexity of the cerebral cortex. There is, however, no universal agreement on the notion of surface complexity and there are various methods in literature that evaluate different aspects of cortical folding. In this paper, we give two intuitive interpretations on folding quantification based on the magnitude and variation of the mean curvature of the cortical surface. We then present a local spectral analysis of the mean curvature to introduce two local gyrification indices that satisfy our interpretations...
November 29, 2016: IEEE Transactions on Medical Imaging
https://www.readbyqxmd.com/read/27911950/a-specialized-multi-transmit-head-coil-for-high-resolution-fmri-of-the-human-visual-cortex-at-7t
#11
Shubharthi Sengupta, Alard Roebroeck, Valentin G Kemper, Benedikt A Poser, Jan Zimmermann, Rainer Goebel, Gregor Adriany
PURPOSE: To design, construct and validate radiofrequency (RF) transmit and receive phased array coils for high-resolution visual cortex imaging at 7 Tesla. METHODS: A 4 channel transmit and 16 channel receive array was constructed on a conformal polycarbonate former. Transmit field efficiency and homogeneity were simulated and validated, along with the Specific Absorption Rate, using [Formula: see text] mapping techniques and electromagnetic simulations. Receiver signal-to-noise ratio (SNR), temporal SNR (tSNR) across EPI time series, g-factors for accelerated imaging and noise correlations were evaluated and compared with a commercial 32 channel whole head coil...
2016: PloS One
https://www.readbyqxmd.com/read/27911842/map-reading-navigating-from-maps-and-the-medial-temporal-lobe
#12
Zhisen J Urgolites, Soyun Kim, Ramona O Hopkins, Larry R Squire
We administered map-reading tasks in which participants navigated an array of marks on the floor by following paths on hand-held maps that made up to nine turns. The burden on memory was minimal because the map was always available. Nevertheless, because the map was held in a fixed position in relation to the body, spatial computations were continually needed to transform map coordinates into geographical coordinates as participants followed the maps. Patients with lesions limited to the hippocampus (n = 5) performed similar to controls at all path lengths (experiment 1)...
November 28, 2016: Proceedings of the National Academy of Sciences of the United States of America
https://www.readbyqxmd.com/read/27909000/distinct-contributions-of-dorsal-and-ventral-streams-to-imitation-of-tool-use-and-communicative-gestures
#13
Andrea Dressing, Kai Nitschke, Dorothee Kümmerer, Tobias Bormann, Lena Beume, Charlotte S M Schmidt, Vera M Ludwig, Irina Mader, Klaus Willmes, Michel Rijntjes, Christoph P Kaller, Cornelius Weiller, Markus Martin
Imitation of tool-use gestures (transitive; e.g., hammering) and communicative emblems (intransitive; e.g., waving goodbye) is frequently impaired after left-hemispheric lesions. We aimed 1) to identify lesions related to deficient transitive or intransitive gestures, 2) to delineate regions associated with distinct error types (e.g., hand configuration, kinematics), and 3) to compare imitation to previous data on pantomimed and actual tool use. Of note, 156 patients (64.3 ± 14.6 years; 56 female) with first-ever left-hemispheric ischemic stroke were prospectively examined 4...
November 30, 2016: Cerebral Cortex
https://www.readbyqxmd.com/read/27907083/effects-of-acute-systemic-hypoxia-and-hypercapnia-on-brain-damage-in-a-rat-model-of-hypoxia-ischemia
#14
Wanchao Yang, Xuezhong Zhang, Nan Wang, Jing Tan, Xianhai Fang, Qi Wang, Tao Tao, Wenzhi Li
Therapeutic hypercapnia has the potential for neuroprotection after global cerebral ischemia. Here we further investigated the effects of different degrees of acute systemic hypoxia in combination with hypercapnia on brain damage in a rat model of hypoxia and ischemia. Adult wistar rats underwent unilateral common carotid artery (CCA) ligation for 60 min followed by ventilation with normoxic or systemic hypoxic gas containing 11%O2,13%O2,15%O2 and 18%O2 (targeted to PaO2 30-39 mmHg, 40-49 mmHg, 50-59 mmHg, and 60-69 mmHg, respectively) or systemic hypoxic gas containing 8% carbon dioxide (targeted to PaCO2 60-80 mmHg) for 180 min...
2016: PloS One
https://www.readbyqxmd.com/read/27906525/the-clinical-utility-of-qsm-disease-diagnosis-medical-management-and-surgical-planning
#15
REVIEW
Sarah Eskreis-Winkler, Yan Zhang, Jingwei Zhang, Zhe Liu, Alexey Dimov, Ajay Gupta, Yi Wang
Quantitative susceptibility mapping (QSM) is an MR technique that depicts and quantifies magnetic susceptibility sources. Mapping iron, the dominant susceptibility source in the brain, has many important clinical applications. Herein, we review QSM applications in the diagnosis, medical management, and surgical treatment of disease. To assist in early disease diagnosis, QSM can identify elevated iron levels in the motor cortex of amyotrophic lateral sclerosis patients, in the substantia nigra of Parkinson's disease (PD) patients, in the globus pallidus, putamen, and caudate of Huntington's disease patients, and in the basal ganglia of Wilson's disease patients...
December 1, 2016: NMR in Biomedicine
https://www.readbyqxmd.com/read/27906169/automated-identification-of-mouse-visual-areas-with-intrinsic-signal-imaging
#16
Ashley L Juavinett, Ian Nauhaus, Marina E Garrett, Jun Zhuang, Edward M Callaway
Intrinsic signal optical imaging (ISI) is a rapid and noninvasive method for observing brain activity in vivo over a large area of the cortex. Here we describe our protocol for mapping retinotopy to identify mouse visual cortical areas using ISI. First, surgery is performed to attach a head frame to the mouse skull (∼1 h). The next day, intrinsic activity across the visual cortex is recorded during the presentation of a full-field drifting bar in the horizontal and vertical directions (∼2 h). Horizontal and vertical retinotopic maps are generated by analyzing the response of each pixel during the period of the stimulus...
January 2017: Nature Protocols
https://www.readbyqxmd.com/read/27903720/oscillatory-dynamics-underlying-perceptual-narrowing-of-native-phoneme-mapping-from-6-to-12-months-of-age
#17
Silvia Ortiz-Mantilla, Jarmo A Hämäläinen, Teresa Realpe-Bonilla, April A Benasich
: During the first months of life, human infants process phonemic elements from all languages similarly. However, by 12 months of age, as language-specific phonemic maps are established, infants respond preferentially to their native language. This process, known as perceptual narrowing, supports neural representation and thus efficient processing of the distinctive phonemes within the sound environment. Although oscillatory mechanisms underlying processing of native and non-native phonemic contrasts were recently delineated in 6-month-old infants, the maturational trajectory of these mechanisms remained unclear...
November 30, 2016: Journal of Neuroscience: the Official Journal of the Society for Neuroscience
https://www.readbyqxmd.com/read/27903705/organization-of-the-claustrum-to-entorhinal-cortical-connection-in-mice
#18
Takuma Kitanishi, Naoki Matsuo
: The claustrum, a subcortical structure situated between the insular cortex and striatum, is reciprocally connected with almost all neocortical regions. Based on this connectivity, the claustrum has been postulated to integrate multisensory information and, in turn, coordinate widespread cortical activity. While studies have identified how sensory information is mapped onto the claustrum, the function of individual topographically-arranged claustro-cortical pathways has been little explored...
November 30, 2016: Journal of Neuroscience: the Official Journal of the Society for Neuroscience
https://www.readbyqxmd.com/read/27903438/neurite-density-imaging-versus-imaging-of-microscopic-anisotropy-in-diffusion-mri-a-model-comparison-using-spherical-tensor-encoding
#19
Björn Lampinen, Filip Szczepankiewicz, Johan Mårtensson, Danielle van Westen, Pia C Sundgren, Markus Nilsson
In diffusion MRI (dMRI), microscopic diffusion anisotropy can be obscured by orientation dispersion. Separation of these properties is of high importance, since it could allow dMRI to non-invasively probe elongated structures such as neurites (axons and dendrites). However, conventional dMRI, based on single diffusion encoding (SDE), entangles microscopic anisotropy and orientation dispersion with intra-voxel variance in isotropic diffusivity. SDE-based methods for estimating microscopic anisotropy, such as the neurite orientation dispersion and density imaging (NODDI) method, must thus rely on model assumptions to disentangle these features...
November 26, 2016: NeuroImage
https://www.readbyqxmd.com/read/27903187/stereotactic-diffusion-tensor-imaging-tractography-for-gamma-knife-radiosurgery
#20
Cormac G Gavin, H Ian Sabin
OBJECTIVE The integration of modern neuroimaging into treatment planning has increased the therapeutic potential and safety of stereotactic radiosurgery. The authors report their method of integrating stereotactic diffusion tensor imaging (DTI) tractography into conventional treatment planning for Gamma Knife radiosurgery (GKRS). The aim of this study was to demonstrate the feasibility of this technique and to address some of the technical limitations of previously reported techniques. METHODS Twenty patients who underwent GKRS composed the study cohort...
December 2016: Journal of Neurosurgery
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