Read by QxMD icon Read

Cortex mapping

Sophie Laguesse, Nadege Morisot, Khanhky Phamluong, Dorit Ron
We previously reported that the kinase AKT is activated in the nucleus accumbens (NAc) of rodents in response to excessive consumption of alcohol. One of the important downstream targets of AKT is the mammalian Target Of Rapamycin in Complex 1 (mTORC1), which was also activated by alcohol intake. mTORC1 controls dendritic protein translation, and we showed that the mTORC1-dependent translational machinery is activated in the NAc in response to alcohol intake. Importantly, systemic or intra-NAc inhibition of the AKT/mTORC1 pathway attenuated alcohol-drinking behaviors...
October 20, 2016: Addiction Biology
Jillian Iafrati, Arnaud Malvache, Cecilia Gonzalez Campo, M Juliana Orejarena, Olivier Lassalle, Lamine Bouamrane, Pascale Chavis
The postnatal maturation of the prefrontal cortex (PFC) represents a period of increased vulnerability to risk factors and emergence of neuropsychiatric disorders. To disambiguate the pathophysiological mechanisms contributing to these disorders, we revisited the endophenotype approach from a developmental viewpoint. The extracellular matrix protein reelin which contributes to cellular and network plasticity, is a risk factor for several psychiatric diseases. We mapped the aggregate effect of the RELN risk allele on postnatal development of PFC functions by cross-sectional synaptic and behavioral analysis of reelin-haploinsufficient mice...
October 21, 2016: Scientific Reports
Bok Soon Go, Sarah M Barry, Jacqueline F McGinty
Cocaine self-administration induces dysfunctional neuroadaptations in the prefrontal cortex that underlie relapse to cocaine-seeking. Cocaine self-administration disturbs glutamatergic transmission in the nucleus accumbens that is prevented by infusion of brain-derived neurotrophic factor (BDNF) into the prelimbic area of the prefrontal cortex. Intra-prelimbic infusion of BDNF decreases cocaine-seeking in a TrkB-ERK MAP kinase-dependent manner. Neuronal activity triggers an interaction between TrkB receptors and NMDA receptors, leading to ERK activation...
October 17, 2016: European Neuropsychopharmacology: the Journal of the European College of Neuropsychopharmacology
Siyu Zhang, Min Xu, Wei-Cheng Chang, Chenyan Ma, Johnny Phong Hoang Do, Daniel Jeong, Tiffany Lei, Jiang Lan Fan, Yang Dan
Long-range projections from the frontal cortex are known to modulate sensory processing in multiple modalities. Although the mouse has become an increasingly important animal model for studying the circuit basis of behavior, the functional organization of its frontal cortical long-range connectivity remains poorly characterized. Here we used virus-assisted circuit mapping to identify the brain networks for top-down modulation of visual, somatosensory and auditory processing. The visual cortex is reciprocally connected to the anterior cingulate area, whereas the somatosensory and auditory cortices are connected to the primary and secondary motor cortices...
October 17, 2016: Nature Neuroscience
Reza Farivar, Simon Clavagnier, Bruce C Hansen, Ben Thompson, Robert F Hess
Complex natural scenes can be decomposed into their oriented spatial frequency (SF) and phase relationships, both of which are represented locally at the earliest stages of cortical visual processing. The SF preference map in the human cortex, obtained using synthetic stimuli, is orderly and correlates strongly with eccentricity. In addition, early visual areas show sensitivity to the phase information that describes the relationship between SFs and thereby dictates the structure of the image. Taken together, two possibilities arise for the joint representation of SF and phase: either the entirety of the cortical SF map is uniformly sensitive to phase, or a particular set of SFs is selectively phase sensitive-for example, greater phase sensitivity for higher SFs that define fine-scale edges in a complex scene...
October 17, 2016: Journal of Physiology
Paul Cumming, Jürgen Gallinat
This Editorial highlights a study by Bagga and coworkers (2016) in the current issue of the Journal of Neurochemistry entitled "Mapping the alteration in brain glutamate with glutamate chemical exchange saturation transfer (GluCEST) magnetic resonance imaging in mice with MPTP-induced parkinsonism, a model of dopamine deficiency." Using their spectroscopic procedure, Bagga et al. discern unexpected relative increases in the cortical glutamate content of parkinsonian mice. Their results suggest the occurrence of a simple relationship between striatal astrogliosis and tissue glutamate content, presumably in relation to enhanced glutamate/glutamine cycling...
October 16, 2016: Journal of Neurochemistry
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
Takashi Shiromoto, Naohiko Okabe, Feng Lu, Emi Maruyama-Nakamura, Naoyuki Himi, Kazuhiko Narita, Yoshiki Yagita, Kazumi Kimura, Osamu Miyamoto
BACKGROUND AND OBJECTIVE: Endogenous neurogenesis is associated with functional recovery after stroke, but the roles it plays in such recovery processes are unknown. This study aims to clarify the roles of endogenous neurogenesis in functional recovery and motor map reorganization induced by rehabilitative therapy after stroke by using a rat model of cerebral ischemia (CI). METHODS: Ischemia was induced via photothrombosis in the caudal forelimb area of the rat cortex...
October 12, 2016: Journal of Stroke and Cerebrovascular Diseases: the Official Journal of National Stroke Association
Konstantinos Nasiotis, Simon Clavagnier, Sylvain Baillet, Christopher C Pack
Magnetoencephalography (MEG) is used in clinical and fundamental studies of brain functions, primarily for the excellent temporal resolution it provides. The spatial resolution is often assumed to be poor, because of the ill-posed nature of MEG source modeling. However, the question of spatial resolution in MEG has seldom been studied in quantitative detail. Here we use the well-known retinotopic organization of the primary visual cortex (V1) as a benchmark for estimating the spatial resolution of MEG source imaging...
October 12, 2016: NeuroImage
Zoey J Isherwood, Mark M Schira, Branka Spehar
Natural scenes share a consistent distribution of energy across spatial frequencies (SF) known as the 1/f(α) amplitude spectrum (α ≈ 0.8 - 1.5, mean 1.2). This distribution is scale-invariant, which is a fractal characteristic of natural scenes with statistically similar structure at different spatial scales. While the sensitivity of the visual system to the 1/f properties of natural scenes has been studied extensively using psychophysics, relatively little is known about the tuning of cortical responses to these properties...
October 11, 2016: NeuroImage
Xabier Urra, Carlos Laredo, Yashu Zhao, Sergio Amaro, Salvatore Rudilosso, Arturo Renú, Alberto Prats-Galino, Anna M Planas, Laura Oleaga, Ángel Chamorro
BACKGROUND: Infections represent the most frequent medical complications in stroke patients. Their main determinants are dysphagia and a transient state of immunodepression. We analyzed whether distinct anatomical brain regions were associated with the occurrence of stroke-associated infections or immunodepression. MATERIALS AND METHODS: In 106 patients with acute ischemic stroke, we evaluated the incidence of pneumonia, urinary tract infection, or other infections together with the characterization of biomarkers of immunodepression...
October 11, 2016: Brain, Behavior, and Immunity
Tamar Flash, Emilio Bizzi
Here we review recent studies of the cortical circuits subserving the control of posture and movement. This topic is addressed from neurophysiological and evolutionary perspectives describing recent advancements achieved through experimental studies in humans and non-human primates. We also describe current debates and controversies concerning motor mapping within the motor cortex and the different computational approaches aimed at resolving the mystery around motor representations and computations. In recent years there is growing interest in the possibly modular organization of motor representations and dynamical processes and the potential of such studies to provide new clues into motor information processing...
October 10, 2016: Current Opinion in Neurobiology
Raz Leib, Firas Mawase, Amir Karniel, Opher Donchin, John Rothwell, Ilana Nisky, Marco Davare
: How motion and sensory inputs are combined to assess an object's stiffness is still unknown. Here, we provide evidence for the existence of a stiffness estimator in the human posterior parietal cortex (PPC). We showed previously that delaying force feedback with respect to motion when interacting with an object caused participants to underestimate its stiffness. We found that applying theta-burst transcranial magnetic stimulation (TMS) over the PPC, but not the dorsal premotor cortex, enhances this effect without affecting movement control...
October 12, 2016: Journal of Neuroscience: the Official Journal of the Society for Neuroscience
Ursula I Tuor, Min Qiao, Manasi Sule, Melissa Morgunov, Tadeusz Foniok
Stroke is a major cause of disability in adults and children. Recently, we have developed an adult rat model of minor stroke containing a peri-infarct region with a modest T2 increase and mild ischemic damage. We hypothesized that a neonatal minor stroke with mild peri-ischemic changes could also be produced, but with potential ontogenic differences. Using our minor photothrombosis method, we produced a range of severities of ischemic lesions (mini, minor, moderate and severe) within magnetic resonance imaging (MRI) slices of adult and neonatal rats...
October 12, 2016: NMR in Biomedicine
Laura D Lewis, Kawin Setsompop, Bruce R Rosen, Jonathan R Polimeni
Oscillatory neural dynamics play an important role in the coordination of large-scale brain networks. High-level cognitive processes depend on dynamics evolving over hundreds of milliseconds, so measuring neural activity in this frequency range is important for cognitive neuroscience. However, current noninvasive neuroimaging methods are not able to precisely localize oscillatory neural activity above 0.2 Hz. Electroencephalography and magnetoencephalography have limited spatial resolution, whereas fMRI has limited temporal resolution because it measures vascular responses rather than directly recording neural activity...
October 11, 2016: Proceedings of the National Academy of Sciences of the United States of America
Joel Pearson, Rocco Chiou, Sebastian Rogers, Marcus Wicken, Stewart Heitmann, Bard Ermentrout
Hallucinations occur in both normal and clinical populations. Due to their unpredictability and complexity, the mechanisms underlying hallucinations remain largely untested. Here we show that visual hallucinations can be induced in the normal population by visual flicker, limited to an annulus that constricts content complexity to simple moving grey blobs, allowing objective mechanistic investigation. Hallucination strength peaked at ~11 Hz flicker and was dependent on cortical processing. Hallucinated motion speed increased with flicker rate, when mapped onto visual cortex it was independent of eccentricity, underwent local sensory adaptation and showed the same bistable and mnemonic dynamics as sensory perception...
October 11, 2016: ELife
Nikola K Kasabov, Maryam Gholami Doborjeh, Zohreh Gholami Doborjeh
This paper introduces a new methodology for dynamic learning, visualization, and classification of functional magnetic resonance imaging (fMRI) as spatiotemporal brain data. The method is based on an evolving spatiotemporal data machine of evolving spiking neural networks (SNNs) exemplified by the NeuCube architecture [1]. The method consists of several steps: mapping spatial coordinates of fMRI data into a 3-D SNN cube (SNNc) that represents a brain template; input data transformation into trains of spikes; deep, unsupervised learning in the 3-D SNNc of spatiotemporal patterns from data; supervised learning in an evolving SNN classifier; parameter optimization; and 3-D visualization and model interpretation...
October 6, 2016: IEEE Transactions on Neural Networks and Learning Systems
Corin Kuang, Lisa Buchy, Mariapaola Barbato, Carolina Makowski, Frank P MacMaster, Signe Bray, Stephanie Deighton, Jean Addington
Cognitive insight is described as a balance between one's self-reflectiveness (recognition and correction of dysfunctional reasoning), and self-certainty (overconfidence). Neuroimaging studies have linked the ventrolateral prefrontal cortex (VLPFC) to cognitive insight in people with psychosis. However, the relationship between cognitive insight and structural connectivity between the VLPFC and other brain areas is unknown. Here, we investigated the modulation of cognitive insight on structural covariance networks involving the VLPFC in a first-episode psychosis sample...
October 6, 2016: Schizophrenia Research
Nobuo Kunori, Ichiro Takashima
The motor cortex of rats contains two forelimb motor areas; the caudal forelimb area (CFA) and the rostral forelimb area (RFA). Although the RFA is thought to correspond to the premotor and/or supplementary motor cortices of primates, which are higher-order motor areas that receive somatosensory inputs, it is unknown whether the RFA of rats receives somatosensory inputs in the same manner. To investigate this issue, voltage-sensitive dye (VSD) imaging was used to assess the motor cortex in rats following a brief electrical stimulation of the forelimb...
October 7, 2016: European Journal of Neuroscience
Ying Cui, Xia Liang, Hong Gu, Yuzheng Hu, Zhen Zhao, Xiang-Yu Yang, Cheng Qian, Yihong Yang, Gao-Jun Teng
To explore the effect of T2DM on cerebral perfusion, and the relationship between cerebral perfusion changes and cognitive impairment as well as diabetic variables, by using a whole-brain arterial spin-labeling (ASL) MRI technique. This prospective study was approved by the local institutional review board and was performed between November 2012 and October 2013. All subjects provided informed consent. Forty T2DM patients and 41 age-, sex- and education-matched healthy controls were included. Cerebral blood flow (CBF) map was obtained by pulsed ASL perfusion imaging at 3 T MRI...
October 6, 2016: Brain Imaging and Behavior
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"