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Primary visual cortex

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https://www.readbyqxmd.com/read/28648888/benchmarking-laminar-fmri-neuronal-spiking-and-synaptic-activity-during-top-down-and-bottom-up-processing-in-the-different-layers-of-cortex
#1
REVIEW
Matthew W Self, Timo van Kerkoerle, Rainer Goebel, Pieter R Roelfsema
High resolution laminar fMRI is beginning to probe responses in the different layers of cortex. What can we expect this exciting new technique to discover about cortical processing and how can we verify that it is producing an accurate picture of the underlying laminar differences in neural processing? This review will address our knowledge of laminar cortical circuitry gained from electrophysiological studies in macaque monkeys with a focus on the primary visual cortex, as this area has been most often targeted in both laminar electrophysiological and fMRI studies...
June 22, 2017: NeuroImage
https://www.readbyqxmd.com/read/28644111/visual-dot-interaction-with-short-term-memory
#2
Faustin Armel Etindele Sosso
AIM: Many neurodegenerative diseases have a memory component. Brain structures related to memory are affected by environmental stimuli, and it is difficult to dissociate effects of all behavior of neurons. MATERIALS & METHODS: Here, visual cortex of mice was stimulated with gratings and dot, and an observation of neuronal activity before and after was made. Bandwidth, firing rate and orientation selectivity index were evaluated. RESULTS: A primary communication between primary visual cortex and short-term memory appeared to show an interesting path to train cognitive circuitry and investigate the basics mechanisms of the neuronal learning...
June 23, 2017: Neurodegenerative Disease Management
https://www.readbyqxmd.com/read/28643417/congenital-deafness-affects-deep-layers-in-primary-and-secondary-auditory-cortex
#3
Christoph Berger, Daniela Kühne, Verena Scheper, A Kral
Congenital deafness leads to functional deficits in the auditory cortex for which early cochlear implantation can effectively compensate. Most of these deficits have been demonstrated functionally. Furthermore, the majority of previous studies on deafness have involved the primary auditory cortex; knowledge of higher-order areas is limited to effects of cross-modal reorganization. In this study, we compared the cortical cytoarchitecture of four cortical areas in adult hearing and congenitally deaf cats (CDCs): the primary auditory field A1, two secondary auditory fields, namely the dorsal zone (DZ) and second auditory field (A2); and a reference visual association field (area 7) in the same section stained either using Nissl or SMI-32 antibodies...
June 23, 2017: Journal of Comparative Neurology
https://www.readbyqxmd.com/read/28640816/topographic-independent-component-analysis-reveals-random-scrambling-of-orientation-in-visual-space
#4
Marina Martinez-Garcia, Luis M Martinez, Jesús Malo
Neurons at primary visual cortex (V1) in humans and other species are edge filters organized in orientation maps. In these maps, neurons with similar orientation preference are clustered together in iso-orientation domains. These maps have two fundamental properties: (1) retinotopy, i.e. correspondence between displacements at the image space and displacements at the cortical surface, and (2) a trade-off between good coverage of the visual field with all orientations and continuity of iso-orientation domains in the cortical space...
2017: PloS One
https://www.readbyqxmd.com/read/28633367/cortical-glutamate-in-migraine
#5
Ronald Zielman, Jannie P Wijnen, Andrew Webb, Gerrit L J Onderwater, Itamar Ronen, Michel D Ferrari, Hermien E Kan, Gisela M Terwindt, Mark C Kruit
Cortical hyperexcitability due to enhanced glutamatergic activity has been implicated in migraine pathophysiology but direct evidence is lacking. Here we assessed glutamate levels and intracellular mobility of glutamate in the visual cortex of migraineurs in-between attacks. We included 50 migraineurs (23 with aura and 27 without aura) and 24 age- and gender-matched non-headache controls. We used proton magnetic resonance spectroscopy (1H-MRS) and diffusion weighted spectroscopy at 7 T with a single volume of interest (2 × 2 × 3 cm) located in the primary and secondary visual cortex...
June 14, 2017: Brain: a Journal of Neurology
https://www.readbyqxmd.com/read/28628005/emergence-of-visually-evoked-reward-expectation-signals-in-dopamine-neurons-via-the-superior-colliculus-in-v1-lesioned-monkeys
#6
Norihiro Takakuwa, Rikako Kato, Peter Redgrave, Tadashi Isa
Responses of midbrain dopamine (DA) neurons reflecting expected reward from sensory cues are critical for reward-based associative learning. However, critical pathways by which reward-related visual information is relayed to DA neurons remain unclear. To address this question, we investigated Pavlovian conditioning in macaque monkeys with unilateral primary visual cortex (V1) lesions (an animal model of 'blindsight'). Anticipatory licking responses to obtain juice drops were elicited in response to visual conditioned stimuli (CS) in the affected visual field...
June 19, 2017: ELife
https://www.readbyqxmd.com/read/28626250/association-between-changes-in-visual-evoked-magnetic-fields-and-non-motor-features-in-parkinson-s-disease
#7
Yoshiro Fujisawa, Tomomi Minato, Jun-Ichi Uemura, Minoru Hoshiyama, Hirohisa Watanabe, Masaaki Hirayama
Visual dysfunction can be caused by several abnormalities, including dysfunctions in the visual cortex and retina. Our aim was to investigate changes in visual evoked brain responses in the primary visual cortex associated with Parkinson's disease (PD). Sixteen healthy control subjects and ten patients with PD participated in this study. We assessed the visual evoked magnetic field (VEF) using magnetoencephalography (MEG). Checkerboard pattern reversal (CPR) and monotonous grating pattern (MGP) stimulations were used...
February 2017: Nagoya Journal of Medical Science
https://www.readbyqxmd.com/read/28624616/age-related-plasticity-of-the-axon-initial-segment-of-cortical-pyramidal-cells-in-marmoset-monkeys
#8
Nafiseh Atapour, Marcello G P Rosa
Structural plasticity of the axon initial segment (AIS), the site of action potential initiation, is observed as part of the normal early development of the cortex, as well as in association with injury and disease. Here, we show that structural AIS plasticity also occurs with normal aging in adult marmosets. Immunohistochemical techniques were used to reveal the extent of the AIS of layer 2/3A pyramidal cells in 8 neocortical areas. We found that the AIS length varied significantly between areas in young adult (2-3 years old) marmosets, with neurons in frontal area 14C having the longest AIS, and those in the primary visual cortex the shortest...
May 22, 2017: Neurobiology of Aging
https://www.readbyqxmd.com/read/28615963/frequency-dependent-changes-in-sensorimotor-and-pain-affective-systems-induced-by-empathy-for-pain
#9
Yoshimasa Motoyama, Katsuya Ogata, Sumio Hoka, Shozo Tobimatsu
BACKGROUND: Empathy for pain helps us to understand the pain of others indirectly. To better comprehend the processing of empathic pain, we report the frequency-dependent modulation of cortical oscillations induced by watching movies depicting pain using high-density electroencephalography (EEG), magnetoencephalography (MEG), and motor evoked potentials (MEP). METHODS: Event-related desynchronization of EEG and MEG was assessed while participants viewed videos of painful (needle) or neutral (cotton swab) situations...
2017: Journal of Pain Research
https://www.readbyqxmd.com/read/28611654/age-related-gene-expression-in-the-frontal-cortex-suggests-synaptic-function-changes-in-specific-inhibitory-neuron-subtypes
#10
Leon French, TianZhou Ma, Hyunjung Oh, George C Tseng, Etienne Sibille
Genome-wide expression profiling of the human brain has revealed genes that are differentially expressed across the lifespan. Characterizing these genes adds to our understanding of both normal functions and pathological conditions. Additionally, the specific cell-types that contribute to the motor, sensory and cognitive declines during aging are unclear. Here we test if age-related genes show higher expression in specific neural cell types. Our study leverages data from two sources of murine single-cell expression data and two sources of age-associations from large gene expression studies of postmortem human brain...
2017: Frontiers in Aging Neuroscience
https://www.readbyqxmd.com/read/28610902/post-stimulus-fmri-and-eeg-responses-evidence-for-a-neuronal-origin-hypothesised-to-be-inhibitory
#11
K J Mullinger, M T Cherukara, R B Buxton, S T Francis, S D Mayhew
Post-stimulus undershoots, negative responses following cessation of stimulation, are widely observed in functional magnetic resonance (fMRI) blood oxygenation level dependent (BOLD) data. However, the debate surrounding whether the origin of this response phase is neuronal or vascular, and whether it provides functionally relevant information, that is additional to what is contained in the primary response, means that undershoots are widely overlooked. We simultaneously recorded electroencephalography (EEG), BOLD and cerebral blood-flow (CBF) [obtained from arterial spin labelled (ASL) fMRI] fMRI responses to hemifield checkerboard stimulation to test the potential neural origin of the fMRI post-stimulus undershoot...
June 10, 2017: NeuroImage
https://www.readbyqxmd.com/read/28605527/effect-of-transcranial-direct-current-stimulation-of-the-motor-cortex-on-visceral-pain-in-patients-with-hepatocellular-carcinoma
#12
Nagwa Mostafa Ibrahim, Khaled Mohamed Abdelhameed, Shereen Mamdouh Mohamed Kamal, Eman Mohamed Hussein Khedr, Hassan Ibrahim Mohamed Kotb
Objective. : Hepatocellular carcinoma (HCC) is frequently associated with visceral pain. Transcranial direct current stimulation (tDCS) has been proven to reduce chronic pain; however, its effectiveness in malignant visceral pain is unknown. This study aimed to investigate the effects of tDCS in patients with visceral pain due to HCC. Design. : This is a randomized, sham-controlled, double-blind, prospective study. Forty patients with visceral pain due to HCC were enrolled and randomly assigned into two groups: a real and a sham group; tDCS was applied over the primary motor area (M1) for 10 consecutive days (2 mA, 30 minutes)...
June 12, 2017: Pain Medicine: the Official Journal of the American Academy of Pain Medicine
https://www.readbyqxmd.com/read/28602762/different-patterns-of-changes-between-actin-dynamics-and-synaptic-density-in-the-rat-s-primary-visual-cortex-during-a-special-period-of-visual-development
#13
Mei-Qing Chen, Ai-Ling Bi, Yue-Ying Zhang, Qin Yan, Yuan-Yuan Sun, Xiu-Yan Zhang, Xian-Zhen Ma, Hong-Sheng Bi
In our previous study, we found that the normalized levels of the synaptosomal filament actin (F-actin) to monomeric global actin (G-actin) ratio in the primary visual cortex (V1) of rats was significantly lower on postnatal day (P) 45 compared with P30, however, the synaptic density in the monocular area of primary visual cortex (V1M) maintained a stable high level from P30 to P45. The mechanisms underlying the different patterned of change in synaptic density and actin rearrangements from P30 to P45 are unclear...
June 8, 2017: Brain Research Bulletin
https://www.readbyqxmd.com/read/28602353/visuomotor-coupling-shapes-the-functional-development-of-mouse-visual-cortex
#14
Alexander Attinger, Bo Wang, Georg B Keller
The emergence of sensory-guided behavior depends on sensorimotor coupling during development. How sensorimotor experience shapes neural processing is unclear. Here, we show that the coupling between motor output and visual feedback is necessary for the functional development of visual processing in layer 2/3 (L2/3) of primary visual cortex (V1) of the mouse. Using a virtual reality system, we reared mice in conditions of normal or random visuomotor coupling. We recorded the activity of identified excitatory and inhibitory L2/3 neurons in response to transient visuomotor mismatches in both groups of mice...
June 15, 2017: Cell
https://www.readbyqxmd.com/read/28602145/neural-correlate-of-internet-use-in-patients-undergoing-psychological-treatment-for-internet-addiction
#15
Carlo Lai, Daniela Altavilla, Marianna Mazza, Silvia Scappaticci, Renata Tambelli, Paola Aceto, Massimiliano Luciani, Stefano Corvino, David Martinelli, Flaminia Alimonti, Federico Tonioni
BACKGROUND: The new version of Diagnostic and Statistical Manual of Mental Disorders (DSM-5th) proposed the Internet Gaming Disorder for the diagnosis of Internet addiction (IA) considering the neurobiological evidence of the craving. AIMS: The aim was to test the neural correlate in response to the Internet cue in patients with IA. METHODS: Sixteen males with IA diagnosis (clinical group) and 14 healthy male (control group) were recruited for an experimental visual task composed of Internet images and emotional images...
June 2017: Journal of Mental Health
https://www.readbyqxmd.com/read/28600679/resting-state-bold-oscillation-frequency-predicts-vigilance-task-performance-at-both-normal-and-high-environmental-temperatures
#16
Xiaopeng Song, Shaowen Qian, Kai Liu, Shuqin Zhou, Huaiqiu Zhu, Qihong Zou, Yijun Liu, Gang Sun, Jia-Hong Gao
Hyperthermia may impair vigilance functions and lead to slower reaction times (RTs) in the psychomotor vigilance task (PVT) and possibly disturbing cerebral hemodynamic rhythms. To test these hypotheses, we acquired the resting-state BOLD and cerebral blood flow (CBF) data, as well as PVTRTs from 15 participants in two simulated environmental thermal conditions (50 °C/25 °C). We adopted a data-driven method, frequency component analysis, to quantify the mean frequency of the BOLD series of each voxel. Across-subject correlation analysis was employed to detect the brain areas whose BOLD oscillation frequency was correlated with the RTs...
June 9, 2017: Brain Structure & Function
https://www.readbyqxmd.com/read/28594752/residual-vitreous-cortex-at-the-fovea-during-vitrectomy-for-primary-rhegmatogenous-retinal-detachment-repair
#17
Eun Hyung Cho, Hee Chan Ku, Won Il, Eun Koo Lee
PURPOSE: To investigate the frequency of residual cortex and the effectiveness of removal of residual cortex in the fovea during vitrectomy for primary rhegmatogenous retinal detachment repair. METHODS: We retrospectively reviewed the charts and the operative videos of the 80 patients (80 eyes) who underwent vitrectomy for repair and who were observed for more than 6 months. After triamcinolone acetonide injection, we observed residual cortex on the surface of the retina...
June 7, 2017: Retina
https://www.readbyqxmd.com/read/28593193/differential-expression-and-cell-type-specificity-of-perineuronal-nets-in-hippocampus-medial-entorhinal-cortex-and-visual-cortex-examined-in-the-rat-and-mouse
#18
Kristian Kinden Lensjø, Ane Charlotte Christensen, Simen Tennøe, Marianne Fyhn, Torkel Hafting
Perineuronal nets (PNNs) are specialized extracellular matrix (ECM) structures that condense around the soma and proximal dendrites of subpopulations of neurons. Emerging evidence suggests that they are involved in regulating brain plasticity. However, the expression of PNNs varies between and within brain areas. A lack of quantitative studies describing the distribution and cell-specificity of PNNs makes it difficult to reveal the functional roles of PNNs. In the current study, we examine the distribution of PNNs and the identity of PNN-enwrapped neurons in three brain areas with different cognitive functions: the dorsal hippocampus, medial entorhinal cortex (mEC) and primary visual cortex (V1)...
May 2017: ENeuro
https://www.readbyqxmd.com/read/28591797/cell-class-dependent-intracortical-connectivity-and-output-dynamics-of-layer-6-projection-neurons-of-the-rat-primary-visual-cortex
#19
Florence Cotel, Lee N Fletcher, Simon Kalita-de Croft, John Apergis-Schoute, Stephen R Williams
Neocortical information processing is powerfully influenced by the activity of layer 6 projection neurons through control of local intracortical and subcortical circuitry. Morphologically distinct classes of layer 6 projection neuron have been identified in the mammalian visual cortex, which exhibit contrasting receptive field properties, but little information is available on their functional specificity. To address this we combined anatomical tracing techniques with high-resolution patch-clamp recording to identify morphological and functional distinct classes of layer 6 projection neurons in the rat primary visual cortex, which innervated separable subcortical territories...
June 7, 2017: Cerebral Cortex
https://www.readbyqxmd.com/read/28588471/functional-network-connectivity-patterns-between-idiopathic-generalized-epilepsy-with-myoclonic-and-absence-seizures
#20
Qifu Li, Yongmin Chen, Yong Wei, Shengmei Chen, Lin Ma, Zhiyi He, Zhibin Chen
The extensive cerebral cortex and subcortical structures are considered as the major regions related to the generalized epileptiform discharges in idiopathic generalized epilepsy. However, various clinical syndromes and electroencephalogram (EEG) signs exist across generalized seizures, such as the loss of consciousness during absence seizures (AS) and the jerk of limbs during myoclonic seizures (MS). It is presumed that various functional systems affected by discharges lead to the difference in syndromes of these seizures...
2017: Frontiers in Computational Neuroscience
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