keyword
MENU ▼
Read by QxMD icon Read
search

Primary visual cortex

keyword
https://www.readbyqxmd.com/read/29464193/online-li-rtms-during-a-visual-learning-task-differential-impacts-on-visual-circuit-and-behavioral-plasticity-in-adult-ephrin-a2a5-mice
#1
Eugenia Z Poh, Alan R Harvey, Kalina Makowiecki, Jennifer Rodger
Repetitive transcranial magnetic stimulation (rTMS) induces plasticity in normal and abnormal neural circuitries, an effect that may be influenced by intrinsic brain activity during treatment. Here, we study potential synergistic effects between low-intensity rTMS (LI-rTMS) and concurrent neural activity in promoting circuit reorganization and enhancing visual behavior. We used ephrin-A2A5-/- mice, which are known to possess visuotopic mapping errors that are ameliorated by LI-rTMS, and assessed the impact of stimulation when mice were engaged in a visual learning task...
January 2018: ENeuro
https://www.readbyqxmd.com/read/29460981/non-invasive-brain-stimulation-of-motor-cortex-induces-embodiment-when-integrated-with-virtual-reality-feedback
#2
M Bassolino, M Franza, J Bello Ruiz, M Pinardi, T Schmidlin, M A Stephan, M Solca, A Serino, O Blanke
Previous evidence highlighted the multisensory-motor origin of embodiment - i.e., the experience of having a body and of being in control of it- and the possibility of experimentally manipulating it. For instance, an illusory feeling of embodiment towards a fake hand can be triggered by providing synchronous visuo-tactile stimulation to the hand of participants and to a fake hand or by asking participants to move their hand and observe a fake hand moving accordingly (rubber hand illusion, RHI). Here we tested whether it is possible to manipulate embodiment not through stimulation of the participant's hand, but by directly tapping into the brain's hand representation via non-invasive brain stimulation...
February 20, 2018: European Journal of Neuroscience
https://www.readbyqxmd.com/read/29459825/aging-potentiates-lateral-but-not-local-inhibition-of-orientation-processing-in-primary-visual-cortex
#3
Zhengchun Wang, Shan Yu, Yu Fu, Tzvetomir Tzvetanov, Yifeng Zhou
Aging-related declines in vision can decrease well-being of the elderly. Concerning early sensory changes as in the primary visual cortex, physiological and behavioral reports seem contradictory. Neurophysiological studies on orientation tuning properties suggested that neuronal changes might come from decreased cortical local inhibition. However, behavioral results either showed no clear deficits in orientation processing in older adults, or proposed stronger surround suppression. Through psychophysical experiments and computational modeling, we resolved these discrepancies by suggesting that lateral inhibition increased in older adults while neuronal orientation tuning widths, related to local inhibition, stayed globally intact across age...
2018: Frontiers in Aging Neuroscience
https://www.readbyqxmd.com/read/29459718/systematic-generation-of-biophysically-detailed-models-for-diverse-cortical-neuron-types
#4
Nathan W Gouwens, Jim Berg, David Feng, Staci A Sorensen, Hongkui Zeng, Michael J Hawrylycz, Christof Koch, Anton Arkhipov
The cellular components of mammalian neocortical circuits are diverse, and capturing this diversity in computational models is challenging. Here we report an approach for generating biophysically detailed models of 170 individual neurons in the Allen Cell Types Database to link the systematic experimental characterization of cell types to the construction of cortical models. We build models from 3D morphologies and somatic electrophysiological responses measured in the same cells. Densities of active somatic conductances and additional parameters are optimized with a genetic algorithm to match electrophysiological features...
February 19, 2018: Nature Communications
https://www.readbyqxmd.com/read/29459137/microstructural-visual-pathway-abnormalities-in-patients-with-primary-glaucoma-3-t-diffusion-kurtosis-imaging-study
#5
Z F Xu, J S Sun, X H Zhang, Y Y Feng, A Z Pan, M Y Gao, H Zhao
AIM: To evaluate microstructural visual pathway damage in patients with primary glaucoma (PG) by using 3 T diffusion kurtosis imaging (DKI). MATERIALS AND METHODS: The study was approved by the ethics committee, and all participants provided written informed consent. Ten patients with PG were examined. Twenty healthy individuals served as control subjects. DKI was performed with a GE Silent 3 T magnetic resonance imaging (MRI) unit. Mean diffusivity (MD), fractional anisotropy (FA), and mean kurtosis (MK) maps were automatically created...
February 16, 2018: Clinical Radiology
https://www.readbyqxmd.com/read/29458067/fluctuations-of-extracellular-glucose-and-lactate-in-the-mouse-primary-visual-cortex-during-visual-stimulation
#6
Alexandria Béland-Millar, Claude Messier
We measured the extracellular glucose and lactate in the primary visual cortex in the CD-1 mouse using electrochemical electrodes. To gain some additional information on brain metabolism, we examined the impact of systemic injections of lactate and fructose on the brain extracellular glucose and lactate changes observed during visual stimulation. We found that simple stimulation using a flashlight produced a decrease in visual cortex extracellular glucose and an increase in extracellular lactate. Similar results were observed following visual stimulation with an animated movie without soundtrack or the presentation of a novel object...
February 16, 2018: Behavioural Brain Research
https://www.readbyqxmd.com/read/29455363/predicting-autism-spectrum-disorder-using-domain-adaptive-cross-site-evaluation
#7
Runa Bhaumik, Ashish Pradhan, Soptik Das, Dulal K Bhaumik
The advances in neuroimaging methods reveal that resting-state functional fMRI (rs-fMRI) connectivity measures can be potential diagnostic biomarkers for autism spectrum disorder (ASD). Recent data sharing projects help us replicating the robustness of these biomarkers in different acquisition conditions or preprocessing steps across larger numbers of individuals or sites. It is necessary to validate the previous results by using data from multiple sites by diminishing the site variations. We investigated partial least square regression (PLS), a domain adaptive method to adjust the effects of multicenter acquisition...
February 17, 2018: Neuroinformatics
https://www.readbyqxmd.com/read/29450943/cortical-projections-to-the-superior-colliculus-in-gray-squirrels-sciurus-carolinensis
#8
Mary K L Baldwin, Nicole A Young, Denis Matrov, Jon H Kaas
The superior colliculus is an important midbrain structure involved with integrating information from varying sensory modalities and sending motor signals to produce orienting movements toward environmental stimuli. Because of this role, the superior colliculus receives a multitude of sensory inputs from a wide variety of subcortical and cortical structures. Proportionately, the superior colliculus of gray squirrels is among the largest in size of all studied mammals, suggesting the importance of this structure in the behavioral characteristics of gray squirrels...
February 16, 2018: European Journal of Neuroscience
https://www.readbyqxmd.com/read/29450542/optical-properties-influence-visual-cortical-functional-resolution-after-cataract-surgery-and-both-dissociate-from-subjectively-perceived-quality-of-vision
#9
Ângela Sofia Cardoso Miranda, Andreia de Faria Martins Rosa, Miguel José Patrício Dias, Ben M Harvey, Maria Fátima Loureiro da Silva, Miguel de Sá E Sousa Castelo-Branco, Joaquim Carlos Neto Murta
Purpose: To investigate the relation between optical properties, population receptive fields (pRFs), visual function, and subjectively perceived quality of vision after cataract surgery. Methods: The study includes 30 patients who had recently undergone bilateral sequential cataract surgery. We used functional magnetic resonance imaging and pRF modelling methods to assess pRF sizes across visual cortical regions (V1-V3). Subjects also performed a complete ophthalmologic and psychophysical examination and answered a quality of vision questionnaire...
February 1, 2018: Investigative Ophthalmology & Visual Science
https://www.readbyqxmd.com/read/29448128/hubs-in-the-human-fetal-brain-network
#10
Marion I van den Heuvel, Elise Turk, Janessa H Manning, Jasmine Hect, Edgar Hernandez-Andrade, Sonia S Hassan, Roberto Romero, Martijn P van den Heuvel, Moriah E Thomason
Advances in neuroimaging and network analyses have lead to discovery of highly connected regions, or hubs, in the connectional architecture of the human brain. Whether these hubs emerge in utero, has yet to be examined. The current study addresses this question and aims to determine the location of neural hubs in human fetuses. Fetal resting-state fMRI data (N = 105) was used to construct connectivity matrices for 197 discrete brain regions. We discovered that within the connectional functional organization of the human fetal brain key hubs are emerging...
February 6, 2018: Developmental Cognitive Neuroscience
https://www.readbyqxmd.com/read/29444175/tomographic-optical-imaging-of-cortical-responses-after-crossing-nerve-transfer-in-mice
#11
Keiichi Maniwa, Haruyoshi Yamashita, Hiroaki Tsukano, Ryuichi Hishida, Naoto Endo, Minoru Shibata, Katsuei Shibuki
To understand the neural mechanisms underlying the therapeutic effects of crossing nerve transfer for brachial plexus injuries in human patients, we investigated the cortical responses after crossing nerve transfer in mice using conventional and tomographic optical imaging. The distal cut ends of the left median and ulnar nerves were connected to the central cut ends of the right median and ulnar nerves with a sciatic nerve graft at 8 weeks of age. Eight weeks after the operation, the responses in the primary somatosensory cortex (S1) elicited by vibratory stimulation applied to the left forepaw were visualized based on activity-dependent flavoprotein fluorescence changes...
2018: PloS One
https://www.readbyqxmd.com/read/29442388/maximizing-sensitivity-for-fast-gaba-edited-spectroscopy-in-the-visual-cortex-at-7%C3%A2-t
#12
Arjan D Hendriks, Alessio Fracasso, Catalina S Arteaga de Castro, Mark W J M Gosselink, Peter R Luijten, Natalia Petridou, Dennis W J Klomp
The combination of functional MRI (fMRI) and MRS is a promising approach to relate BOLD imaging to neuronal metabolism, especially at high field strength. However, typical scan times for GABA edited spectroscopy are of the order of 6-30 min, which is long compared with functional changes observed with fMRI. The aim of this study is to reduce scan time and increase GABA sensitivity for edited spectroscopy in the human visual cortex, by enlarging the volume of activated tissue in the primary visual cortex. A dedicated setup at 7 T for combined fMRI and GABA MRS is developed...
February 14, 2018: NMR in Biomedicine
https://www.readbyqxmd.com/read/29441578/cell-type-specific-tracing-of-the-subcortical-input-to-primary-visual-cortex-from-the-basal-forebrain
#13
Georgina A Lean, Yong-Jun Liu, David C Lyon
The basal forebrain provides cholinergic inputs to primary visual cortex (V1) that play a key modulatory role on visual function. While basal forebrain afferents terminate in the infragranular layers of V1, acetylcholine is delivered to more superficial layers through volume transmission. Nevertheless, direct synaptic contact in deep layers 5 and 6 may provide a more immediate effect on V1 modulation. Using helper viruses with cell type specific promoters to target retrograde infection of pseudotyped and genetically modified rabies virus evidence was found for direct synaptic input onto V1 inhibitory neurons...
February 14, 2018: Journal of Comparative Neurology
https://www.readbyqxmd.com/read/29440996/is-there-a-canonical-cortical-circuit-for-the-cholinergic-system-anatomical-differences-across-common-model-systems
#14
REVIEW
Jennifer J Coppola, Anita A Disney
Acetylcholine (ACh) is believed to act as a neuromodulator in cortical circuits that support cognition, specifically in processes including learning, memory consolidation, vigilance, arousal and attention. The cholinergic modulation of cortical processes is studied in many model systems including rodents, cats and primates. Further, these studies are performed in cortical areas ranging from the primary visual cortex to the prefrontal cortex and using diverse methodologies. The results of these studies have been combined into singular models of function-a practice based on an implicit assumption that the various model systems are equivalent and interchangeable...
2018: Frontiers in Neural Circuits
https://www.readbyqxmd.com/read/29434547/effects-of-prefrontal-transcranial-direct-current-stimulation-and-motivation-to-quit-in-tobacco-smokers-a-randomized-sham-controlled-double-blind-trial
#15
Maria C Vitor de Souza Brangioni, Danilo A Pereira, Aurore Thibaut, Felipe Fregni, Joaquim P Brasil-Neto, Raphael Boechat-Barros
Transcranial direct current stimulation (tDCS) applied over the dorsolateral prefrontal cortex (DLPFC) has been shown to reduce cravings in tobacco addiction; however, results have been somewhat mixed. In this study, we hypothesized that motivation to quit smoking is a critical factor of tDCS effects in smokers. Therefore, we conducted a double-blind, randomized clinical trial to evaluate the effects of both tDCS and motivation to quit on cigarette consumption and the relationship between these two factors...
2018: Frontiers in Pharmacology
https://www.readbyqxmd.com/read/29431651/development-of-cross-orientation-suppression-and-size-tuning-and-the-role-of-experience
#16
Marjena Popović, Andrea K Stacy, Mihwa Kang, Roshan Nanu, Charlotte E Oettgen, Derek L Wise, József Fiser, Stephen D Van Hooser
Many sensory neural circuits exhibit response normalization, which occurs when the response of a neuron to a combination of multiple stimuli is less than the sum of the responses to the individual stimuli presented alone. In the visual cortex, normalization takes the forms of cross-orientation suppression and surround suppression. At the onset of visual experience, visual circuits are partially developed and exhibit some mature features such as orientation selectivity, but it is unknown whether cross-orientation suppression is present at the onset of visual experience or requires visual experience for its emergence...
February 5, 2018: Journal of Neuroscience: the Official Journal of the Society for Neuroscience
https://www.readbyqxmd.com/read/29430585/dendritic-cell-factor-1-knockout-results-in-visual-deficit-through-the-gaba-system-in-mouse-primary-visual-cortex
#17
Jieyun Shi, Qian Li, Tieqiao Wen
The visual system plays an important role in our daily life. In this study, we found that loss of dendritic cell factor 1 (DCF1) in the primary visual cortex (V1) caused a sight deficit in mice and induced an abnormal increase in glutamic acid decarboxylase 67, an enzyme that catalyzes the decarboxylation of glutamate to gamma aminobutyric acid and CO2, particularly in layer 5. In vivo electrophysiological recordings confirmed a decrease in delta, theta, and beta oscillation power in DCF1-knockout mice. This study presents a previously unknown function of DCF1 in V1, suggests an unknown contact between DCF1 and GABA systems, and provides insight into the mechanism and treatment of visual deficits...
February 12, 2018: Neuroscience Bulletin
https://www.readbyqxmd.com/read/29427808/adaptive-optical-microscopy-for-neurobiology
#18
REVIEW
Cristina Rodríguez, Na Ji
With the ability to correct for the aberrations introduced by biological specimens, adaptive optics-a method originally developed for astronomical telescopes-has been applied to optical microscopy to recover diffraction-limited imaging performance deep within living tissue. In particular, this technology has been used to improve image quality and provide a more accurate characterization of both structure and function of neurons in a variety of living organisms. Among its many highlights, adaptive optical microscopy has made it possible to image large volumes with diffraction-limited resolution in zebrafish larval brains, to resolve dendritic spines over 600μm deep in the mouse brain, and to more accurately characterize the orientation tuning properties of thalamic boutons in the primary visual cortex of awake mice...
February 6, 2018: Current Opinion in Neurobiology
https://www.readbyqxmd.com/read/29427081/effects-of-tolcapone-and-bromocriptine-on-cognitive-stability-and-flexibility
#19
Ian G M Cameron, Deanna L Wallace, Ahmad Al-Zughoul, Andrew S Kayser, Mark D'Esposito
RATIONALE: The prefrontal cortex (PFC) and basal ganglia (BG) have been associated with cognitive stability and cognitive flexibility, respectively. We hypothesized that increasing PFC dopamine tone by administering tolcapone (a catechol-O-methyltransferase (COMT) inhibitor) to human subjects should promote stability; conversely, increasing BG dopamine tone by administering bromocriptine (a D2 receptor agonist) should promote flexibility. OBJECTIVE: We assessed these hypotheses by administering tolcapone, bromocriptine, and a placebo to healthy subjects who performed a saccadic eye movement task requiring stability and flexibility...
February 9, 2018: Psychopharmacology
https://www.readbyqxmd.com/read/29422846/statokinetic-dissociation-riddoch-phenomenon-in-a-patient-with-homonymous-hemianopsia-as-the-first-sign-of-posterior-cortical-atrophy
#20
Ryuichiro Hayashi, Shigeki Yamaguchi, Toshio Narimatsu, Hiroshi Miyata, Yasushi Katsumata, Masaru Mimura
We report a 60-year-old woman with posterior cortical atrophy (PCA) who presented with left homonymous hemianopsia persisting for 5 years; the patient's condition was observed using static, but not kinetic, perimetry. This statokinetic dissociation of hemianopsia, which is often called Riddoch syndrome, might have been caused by a dysfunction of the right primary visual and visual association cortices, representing a functional imbalance within a disturbed visual cortex. In patients with PCA and visual field defects, both static and kinetic perimetry may be useful for understanding the extent of degeneration in the visual cortex, in addition to examinations of unilateral neglect...
September 2017: Case Reports in Neurology
keyword
keyword
54569
1
2
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"