Read by QxMD icon Read

Cortical reorganization

Lei Tong, Yang Xie, Hongbo Yu
Experiments on the adult visual cortex of cats, ferrets and monkeys have revealed organized spatial relationships between multiple feature maps which can also be reproduced by the Kohonen and elastic net self-organization models. However, attempts to apply these models to simulate the temporal kinetics of monocular deprivation during the critical period, and their effects on the spatial arrangement of feature maps, have led to conflicting results. In this study, we performed monocular deprivation (MD) and chronic imaging in the ferret visual cortex during the critical period of ocular dominance (OD) plasticity...
October 13, 2016: Neuroscience
Lauren P Shapiro, Ryan G Parsons, Anthony J Koleske, Shannon L Gourley
The prevalence of depression, anxiety, schizophrenia, and drug and alcohol use disorders peaks during adolescence. Further, up to 50% of "adult" mental health disorders emerge in adolescence. During adolescence, the prefrontal cortex (PFC) undergoes dramatic structural reorganization, in which dendritic spines and synapses are refined, pruned, and stabilized. Understanding the molecular mechanisms that underlie these processes should help to identify factors that influence the development of psychiatric illness...
October 13, 2016: Journal of Neuroscience Research
Lauren Marussich, Kun-Han Lu, Haiguang Wen, Zhongming Liu
Despite wide applications of functional magnetic resonance imaging (fMRI) to mapping brain activation and connectivity in cortical gray matter, it has rarely been utilized to study white-matter functions. In this study, we investigated the spatiotemporal characteristics of fMRI data within the white matter acquired from humans in the resting state or watching a naturalistic movie. By using independent component analysis and hierarchical clustering, resting-state fMRI data in the white matter were denoised and decomposed into spatially independent components, further assembled into hierarchically organized axonal fiber bundles...
October 5, 2016: NeuroImage
Julien Mysoet, Marie-Hélène Canu, Christophe Gillet, Julie Fourneau, Cyril Garnier, Bruno Bastide, Erwan Dupont
Immobilization, bed rest, or sedentary lifestyle, are known to induce a profound impairment in sensorimotor performance. These alterations are due to a combination of peripheral and central factors. Previous data conducted on a rat model of disuse (hindlimb unloading, HU) have shown a profound reorganization of motor cortex and an impairment of motor performance. Recently, our interest was turned towards the role of insulin-like growth factor 1 (IGF-1) in cerebral plasticity since this growth factor is considered as the mediator of beneficial effects of exercise on the central nervous system, and its cortical level is decreased after a 14-day period of HU...
October 4, 2016: Behavioural Brain Research
Quentin Welniarz, Isabelle Dusart, Emmanuel Roze
The corticospinal tract (CST) plays a major role in cortical control of spinal cord activity. In particular, it is the principal motor pathway for voluntary movements. Here, we discuss: (i) the anatomic evolution and development of the CST across mammalian species, focusing on its role in motor functions; (ii) the molecular mechanisms regulating corticospinal tract formation and guidance during mouse development; and (iii) human disorders associated with abnormal CST development. A comparison of CST anatomy and development across mammalian species first highlights important similarities...
October 5, 2016: Developmental Neurobiology
Serena Bianchi, Laura D Reyes, William D Hopkins, Jared P Taglialatela, Chet C Sherwood
Vocal learning is a key property of spoken language, which might also be present in nonhuman primate species, such as chimpanzees (Pan troglodytes), to a limited degree. While understanding the origins of vocal learning in the primate brain may help shed light on the evolution of speech and language, little is still known regarding the neurobiological correlates of vocal flexibility in nonhuman primates. The current study used voxel-based morphometry (VBM) to assess whether the cerebral cortex of captive chimpanzees that learned to voluntarily produce sounds to attract the attention of a human experimenter (attention-getting sounds) differs in grey matter distribution compared to chimpanzees that do not exhibit this behavior...
October 5, 2016: Scientific Reports
Hadley C Bergstrom
Memories of threatening, fear-evoking events can persist even over a lifetime. While fear memory is widely considered to be a highly persistent and durable form of memory, its circuits are not. This article reviews the dynamic temporal representation of remote fear memory in the brain, at the level of local circuits and distributed networks. Data from the study of Pavlovian cued fear conditioning suggests memory retrieval remains amygdala-dependent, even over protracted time scales, all the while interconnected cortical and subcortical circuits are newly recruited and progressively reorganized...
September 28, 2016: Neuroscience and Biobehavioral Reviews
Kevin J Chalut, Ewa K Paluch
The cortical actin network controls many animal cell shape changes by locally modulating cortical tension. Recent work has provided insight into cortex components and regulators. However, how the network is reorganized in response to cellular signaling, and the role reorganization may play during cell state changes, remain to be determined.
September 26, 2016: Developmental Cell
Jenessa L Seymour, Kathy A Low, Edward L Maclin, Antonio M Chiarelli, Kyle E Mathewson, Monica Fabiani, Gabriele Gratton, Matthew W G Dye
Theories of brain plasticity propose that, in the absence of input from the preferred sensory modality, some specialized brain areas may be recruited when processing information from other modalities, which may result in improved performance. The Useful Field of View task has previously been used to demonstrate that early deafness positively impacts peripheral visual attention. The current study sought to determine the neural changes associated with those deafness-related enhancements in visual performance...
September 23, 2016: Hearing Research
Lijun Chen, Chuanfu Li, Jian Zhai, Anqin Wang, Qin Song, Ying Liu, Ru Ma, Long Han, Yamikani Ndasauka, Xiaoming Li, Hai Li, Xiaochu Zhang
Previous studies have suggested that cortical functional reorganization is associated with motor recovery after stroke and that normal afferent sensory information is very important in that process. In this study, we selected patients who had a stroke in or under the thalamus, with potentially impaired afferent sensory information and analyzed the differences between these patients and healthy controls at three levels: brain regions, the functional connectivity between brain areas, and the whole-brain functional network...
September 23, 2016: Neuroscience Bulletin
A-C Guinchard, N Ghazaleh, M Saenz, E Fornari, J O Prior, P Maeder, S Adib, R Maire
We studied possible brain changes with functional MRI (fMRI) and fluorodeoxyglucose positron emission tomography (FDG-PET) in a patient with a rare, high-intensity "objective tinnitus" (high-level SOAEs) in the left ear of 10 years duration, with no associated hearing loss. This is the first case of objective cochlear tinnitus to be investigated with functional neuroimaging. The objective cochlear tinnitus was measured by Spontaneous Otoacoustic Emissions (SOAE) equipment (frequency 9689 Hz, intensity 57 dB SPL) and is clearly audible to anyone standing near the patient...
September 20, 2016: Hearing Research
Paula Pierozan, Helena Biasibetti, Felipe Schmitz, Helena Ávila, Carolina Gonçalves Fernandes, Regina Pessoa-Pureur, Angela T S Wyse
In the present work, we focused on mechanisms of methylmercury (MeHg) toxicity in primary astrocytes and neurons of rats. Cortical astrocytes and neurons exposed to 0.5-5 μM MeHg present a link among morphological alterations, glutathione (GSH) depletion, glutamate dyshomeostasis, and cell death. Disrupted neuronal cytoskeleton was assessed by decreased neurite length and neurite/neuron ratio. Astrocytes presented reorganization of actin and glial fibrillary acidic protein (GFAP) networks and reduced cytoplasmic area...
September 22, 2016: Molecular Neurobiology
Florie Le Prieult, Serge Christian Thal, Kristin Engelhard, Barbara Imbrosci, Thomas Mittmann
Focal neocortical brain injuries lead to functional alterations, which can spread beyond lesion-neighboring brain areas. The undamaged hemisphere and its associated disturbances after a unilateral lesion, so called transhemispheric diaschisis, have been progressively disclosed over the last decades, they are strongly involved in the pathophysiology, and potentially in the recovery of brain injuries. Understanding the temporal dynamics of these transhemispheric functional changes is crucial to decipher the role of the undamaged cortex in the processes of functional reorganization at different stages post-lesion...
September 21, 2016: Journal of Neurotrauma
Laura E Ramos-Languren, Gabriela García-Díaz, Angélica González-Maciel, Laura E Rosas-López, Antonio Bueno-Nava, Alberto Avila-Luna, Hayde Ramírez-Anguiano, Rigoberto González-Piña
Nowadays, a consensus has been reached that designates the functional and structural reorganization of synapses as the primary mechanisms underlying the process of recovery from brain injury. We have reported that pontine noradrenaline (NA) is increased in animals after cortical ablation (CA). The aim of the present study was to explore the noradrenergic and morphological response after sensorimotor intervention (SMI) in rats injured in the motor cortex. We used male Wistar adult rats allocated in four conditions: sham-operated, injured by cortical ablation, sham-operated with SMI and injured by cortical ablation with SMI...
September 17, 2016: Neurochemical Research
Carrie Falling, Ramakrishnan Mani
BACKGROUND AND AIMS: Alterations in central somatosensory function (e.g. cortical reorganisation) occurs secondary to chronic knee pain. The reorganization can be quantified using a clinical signatory measure, the two-point discrimination threshold (TPDT). In order to differentiate normal variability of TPDT against abnormal thresholds for clinical practice, development of body region specific reference values are required and the factors that determine the TPDT have to be established...
August 5, 2016: Manual Therapy
Andrej Kral, Prasandhya A Yusuf, Rüdiger Land
The theory of predictive coding assumes that higher-order representations influence lower-order representations by generating predictions about sensory input. In congenital deafness, one identified dysfunction is a reduced activation of deep layers in the auditory cortex. Since these layers play a central role for processing top-down influences, congenital deafness might interfere with the integration of top-down and bottom-up information flow. Studies in humans suggest more deficits in higher-order than in primary cortical areas in congenital deafness...
September 13, 2016: Hearing Research
Rodrigo Araneda, Laurent A Renier, Philippe Rombaux, Isabel Cuevas, Anne G De Volder
Over the last decade, functional brain imaging has provided insight to the maturation processes and has helped elucidate the pathophysiological mechanisms involved in brain plasticity in the absence of vision. In case of congenital blindness, drastic changes occur within the deafferented "visual" cortex that starts receiving and processing non visual inputs, including olfactory stimuli. This functional reorganization of the occipital cortex gives rise to compensatory perceptual and cognitive mechanisms that help blind persons achieve perceptual tasks, leading to superior olfactory abilities in these subjects...
2016: Frontiers in Systems Neuroscience
Dominic Kraus, Alireza Gharabaghi
Motor maps acquired with transcranial magnetic stimulation (TMS) are evolving as a biomarker for monitoring disease progression or the effects of therapeutic interventions. High test-retest reliability of this technique for long observation periods is therefore required to differentiate daily or weekly fluctuations from stable plastic reorganization of corticospinal connectivity. In this study, a novel projection, interpolation, and coregistration technique, which considers the individual gyral anatomy, was applied in healthy subjects for biweekly acquired TMS motor maps over a period of twelve weeks...
2016: Neural Plasticity
Imis Dogan, Eugenie Tinnemann, Sandro Romanzetti, Shahram Mirzazade, Ana S Costa, Cornelius J Werner, Stefan Heim, Kathrin Fedosov, Stefanie Schulz, Dagmar Timmann, Ilaria A Giordano, Thomas Klockgether, Jörg B Schulz, Kathrin Reetz
OBJECTIVE: Friedreich's ataxia (FRDA) is a spinocerebellar degenerative disorder, in which cognitive deficits are sparsely explored. In this behavioral and multimodal magnetic resonance imaging (MRI) study, we investigated the neurocognitive profile and cortico-cerebellar dysfunctions underlying executive functioning in individuals with FRDA. METHODS: 22 FRDA patients and 22 controls were clinically and neuropsychologically examined. Fifteen of each underwent structural and functional MRI using a verbal-fluency task with phonemic and semantic conditions...
August 2016: Annals of Clinical and Translational Neurology
Ju-Rong Ding, Xin Ding, Bo Hua, Xingzhong Xiong, Qingsong Wang, Huafu Chen
White matter lesions (WMLs) are frequently detected in elderly people. Previous structural and functional studies have demonstrated that WMLs are associated with cognitive and motor decline. However, the underlying mechanism of how WMLs lead to cognitive decline and motor disturbance remains unclear. We used functional connectivity density mapping (FCDM) to investigate changes in brain functional connectivity in 16 patients with ischemic WMLs and 13 controls. Both short- and long-range FCD maps were computed, and group comparisons were performed between the 2 groups...
September 2016: Medicine (Baltimore)
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"