18,171 results match your criteria technique cortex


The clinical outcomes of scaphoid nonunion treated with a precisely processed autologous bone screw: a case series.

Arch Orthop Trauma Surg 2021 Aug 4. Epub 2021 Aug 4.

Department of Orthopaedic Surgery, Faculty of Medicine, Shimane University, 89-1, Enya, Izumo, Shimane, 693-8501, Japan.

Introduction: Metal implants and bioabsorbable implants are frequently used in orthopaedic surgery, but they have some disadvantages. The usefulness of autologous bone has been described, and a method to precisely process autologous bone into implants such as screws and apply the implants clinically has been desired. We created a new system for manufacturing autologous bone screws during surgery and report five cases of scaphoid nonunion treated with precise autologous bone screws made from the tibial cortex using the new system. Read More

View Article and Full-Text PDF

Anticonvulsant effect of pterostilbene and its influence on the anxiety- and depression-like behavior in the pentetrazol-kindled mice: behavioral, biochemical, and molecular studies.

Psychopharmacology (Berl) 2021 Aug 1. Epub 2021 Aug 1.

Department of Animal Physiology and Pharmacology, Institute of Biological Sciences, Maria Curie-Skłodowska University, Akademicka 19, 20-033, Lublin, Poland.

Rationale: Pterostilbene is the 3,5-dimethoxy derivative of resveratrol with numerous beneficial effects including neuroprotective properties. Experimental studies revealed its anticonvulsant action in the acute seizure tests.

Objectives: The purpose of the present study was to evaluate the effect of pterostilbene in the pentetrazol (PTZ)-induced kindling model of epilepsy in mice as well as to assess some possible mechanisms of its anticonvulsant action in this model. Read More

View Article and Full-Text PDF

Asleep Speech Mapping Using Orofacial Muscles as Surrogates for Motor Speech in Patients Who Cannot Tolerate Awake Surgery: A Case Series.

Cureus 2021 Jun 23;13(6):e15861. Epub 2021 Jun 23.

Neurological Surgery, Northwell Health, New York, USA.

Background Bi-polar electrical cortical stimulation during awake craniotomy has been the gold standard for mapping eloquent cortex to preserve speech. Unfortunately, not all patients can tolerate awake surgery. Monopolar hi-frequency electrical stimulation can be conducted while a patient is under general anesthesia. Read More

View Article and Full-Text PDF

Interrogating theoretical models of neural computation with emergent property inference.

Elife 2021 Jul 29;10. Epub 2021 Jul 29.

Department of Statistics, Columbia University, New York, United States.

A cornerstone of theoretical neuroscience is the circuit model: a system of equations that captures a hypothesized neural mechanism. Such models are valuable when they give rise to an experimentally observed phenomenon -- whether behavioral or a pattern of neural activity -- and thus can offer insights into neural computation. The operation of these circuits, like all models, critically depends on the choice of model parameters. Read More

View Article and Full-Text PDF

Evaluation of structural changes in orbitofrontal cortex in relation to medication overuse in migraine patients: a diffusion tensor imaging study.

Arq Neuropsiquiatr 2021 Jun;79(6):483-488

Gaziosmanpasa Training and Research Hospital, Department of Neurology, Istanbul, Turkey.

Background: Migraine is a prevalent neurological disease that leads to severe headaches. Moreover, it is the commonest among the primary headaches that cause medication overuse headache (MOH). The orbitofrontal cortex (OFC) is one of the structures most associated with medication overuse. Read More

View Article and Full-Text PDF

The role of diffuse correlation spectroscopy and frequency-domain near-infrared spectroscopy in monitoring cerebral hemodynamics during hypothermic circulatory arrests.

JTCVS Tech 2021 Jun 29;7:161-177. Epub 2021 Jan 29.

Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, Mass.

Objectives: Real-time noninvasive monitoring of cerebral blood flow (CBF) during surgery is key to reducing mortality rates associated with adult cardiac surgeries requiring hypothermic circulatory arrest (HCA). We explored a method to monitor cerebral blood flow during different brain protection techniques using diffuse correlation spectroscopy (DCS), a noninvasive optical technique which, combined with frequency-domain near-infrared spectroscopy (FDNIRS), also provides a measure of oxygen metabolism.

Methods: We used DCS in combination with FDNIRS to simultaneously measure hemoglobin oxygen saturation (SO), an index of cerebral blood flow (CBF), and an index of cerebral metabolic rate of oxygen (CMRO) in 12 patients undergoing cardiac surgery with HCA. Read More

View Article and Full-Text PDF

Transient astrocyte-like NG2 glia subpopulation emerges solely following permanent brain ischemia.

Glia 2021 Jul 27. Epub 2021 Jul 27.

Department of Cellular Neurophysiology, Institute of Experimental Medicine, Czech Academy of Sciences, Prague, Czech Republic.

NG2 glia display wide proliferation and differentiation potential under physiological and pathological conditions. Here, we examined these two features following different types of brain disorders such as focal cerebral ischemia (FCI), cortical stab wound (SW), and demyelination (DEMY) in 3-month-old mice, in which NG2 glia are labeled by tdTomato under the Cspg4 promoter. To compare NG2 glia expression profiles following different CNS injuries, we employed single-cell RT-qPCR and self-organizing Kohonen map analysis of tdTomato-positive cells isolated from the uninjured cortex/corpus callosum and those after specific injury. Read More

View Article and Full-Text PDF

Real-time fMRI and EEG neurofeedback: a perspective on applications for the rehabilitation of spatial neglect.

Ann Phys Rehabil Med 2021 Jul 23:101561. Epub 2021 Jul 23.

Laboratory for Behavioral Neurology and Imaging of Cognition, Neuroscience Department, University of Geneva, Geneva, Switzerland.

Spatial neglect is a neuropsychological syndrome characterized by a failure to orient, perceive, and act toward the contralesional side of the space after brain injury. Neglect is one of the most frequent and disabling neuropsychological syndromes following right-hemisphere damage, often persisting in the chronic phase and responsible for a poor functional outcome at hospital discharge. Different rehabilitation approaches have been proposed over the past 60 years, with a variable degree of effectiveness. Read More

View Article and Full-Text PDF

[Communication sound recognition and response modification in the secondary auditory cortex of female mice].

Authors:
S Lei Z Xiao

Nan Fang Yi Ke Da Xue Xue Bao 2021 Jul;41(7):1079-1086

Department of Physiology, School of Basic Medical Sciences, Southern Medical University, Guangzhou 510515, China.

Objective: To study the response characteristics of the secondary auditory cortex (A2) to wriggling calls (WC) and the mechanism of response modulation in female mice.

Methods: We used patch-clamp and immunofluorescence labeling technique to mark and record the action potential and cell type of A2 neurons. Female C57 mice were stimulated with pure tone and white noise (control), 4. Read More

View Article and Full-Text PDF

Longitudinal cortex-wide monitoring of cerebral hemodynamics and oxygen metabolism in awake mice using multi-parametric photoacoustic microscopy.

J Cereb Blood Flow Metab 2021 Jul 26:271678X211034096. Epub 2021 Jul 26.

Department of Biomedical Engineering, 2358University of Virginia, University of Virginia, Charlottesville, VA, USA.

Multi-parametric photoacoustic microscopy (PAM) has emerged as a promising new technique for high-resolution quantification of hemodynamics and oxygen metabolism in the mouse brain. In this work, we have extended the scope of multi-parametric PAM to longitudinal, cortex-wide, awake-brain imaging with the use of a long-lifetime (24 weeks), wide-field (5 × 7 mm), light-weight (2 g), dual-transparency ( light and ultrasound) cranial window. Cerebrovascular responses to the window installation were examined , showing a complete recovery in 18 days. Read More

View Article and Full-Text PDF

Diffusion kurtosis imaging as an imaging biomarker for predicting prognosis in chronic kidney disease patients.

Nephrol Dial Transplant 2021 Jul 24. Epub 2021 Jul 24.

Department of Nephrology, State Key Laboratory of Complex Severe and Rare Diseases.

Background: Renal fibrosis is the strongest prognosis predictor of end-stage renal disease (ESRD) in chronic kidney disease (CKD). Diffusion kurtosis imaging (DKI) is a promising method of magnetic resonance imaging (MRI) successfully used to assess renal fibrosis in IgA nephropathy. This study first evaluated the long-term prognostic value of DKI in CKD patients. Read More

View Article and Full-Text PDF

Modified anterior midline approach to treat hyperextension bicondylar tibial plateau fractures: Surgical technique and clinical experience with 18 cases.

Knee 2021 Jul 20;32:1-8. Epub 2021 Jul 20.

Department of Orthopedics, Xiangya Hospital, Central South University, Changsha, Hunan, China. Electronic address:

Background: We evaluated the modified anterior midline approach and its efficacy for hyperextension bicondylar tibial plateau (HEBTP) fractures.

Methods: From 2015 to 2019, 18 patients with HEBTP fractures with just little posterior cortical displacement were treated using the modified anterior midline approach. The operative protocols are fully described in this article, and the following parameters: articular step-off height (ASH), posterior tibial slope angle (pTSA), and medial tibial plateau angle (mTPA) were measured perioperatively and at the final follow-up. Read More

View Article and Full-Text PDF

In Vivo Super-Resolution Track-Density Imaging for Thalamic Nuclei Identification.

Cereb Cortex 2021 Jul 23. Epub 2021 Jul 23.

Brain Mapping Lab, Department of Biomedical, Dental Sciences and Morphological and Functional Images, University of Messina, 98124 Messina, Italy.

The development of novel techniques for the in vivo, non-invasive visualization and identification of thalamic nuclei has represented a major challenge for human neuroimaging research in the last decades. Thalamic nuclei have important implications in various key aspects of brain physiology and many of them show selective alterations in various neurologic and psychiatric disorders. In addition, both surgical stimulation and ablation of specific thalamic nuclei have been proven to be useful for the treatment of different neuropsychiatric diseases. Read More

View Article and Full-Text PDF

UV-Induced Neuronal Degeneration in the Rat Cerebral Cortex.

Cereb Cortex Commun 2021 1;2(1):tgab006. Epub 2021 Feb 1.

Integrative Neuroscience Research Group, Human Informatics and Interaction Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba 305-8568, Japan.

Irradiation with ultraviolet (UV) light on the cortical surface can induce a focal brain lesion (UV lesion) in rodents. In the present study, we investigated the process of establishing a UV lesion. Rats underwent UV irradiation (365-nm wavelength, 2. Read More

View Article and Full-Text PDF
February 2021

Steady-State Visual Evoked Potentials Elicited from Early Visual Cortex Reflect Both Perceptual Color Space and Cone-Opponent Mechanisms.

Cereb Cortex Commun 2020 1;1(1):tgaa059. Epub 2020 Sep 1.

School of Psychology, University of Aberdeen, William Guild Building, Aberdeen, AB24 3UB, UK.

Colors are represented in the cone-opponent signals, L-M versus S cones, at least up to the level of inputs to the primary visual cortex. We explored the hue selective responses in early cortical visual areas through recordings of steady-state visual evoked potentials (SSVEPs), elicited by a flickering checkerboard whose color smoothly swept around the hue circle defined in a cone-opponent color space. If cone opponency dominates hue representation in the source of SSVEP signals, SSVEP amplitudes as a function of hue should form a profile that is line-symmetric along the cardinal axes of the cone-opponent color space. Read More

View Article and Full-Text PDF
September 2020

Brain perfusion magnetic resonance imaging using pseudocontinuous arterial spin labeling in 314 dogs and cats.

J Vet Intern Med 2021 Jul 22. Epub 2021 Jul 22.

Unit of Diagnostic Imaging, ADVETIA Veterinary Referral Hospital, Vélizy-Villacoublay, France.

Background: Arterial spin labeling (ASL) is a noninvasive brain perfusion magnetic resonance imaging (MRI) technique that has not been assessed in clinical veterinary medicine.

Hypothesis/objectives: To test the feasibility of ASL using a 1.5 Tesla scanner and provide recommendations for optimal quantification of cerebral blood flow (CBF) in dogs and cats. Read More

View Article and Full-Text PDF

Longitudinal neural connection detection using a ferritin-encoding adeno-associated virus vector and in vivo MRI method.

Hum Brain Mapp 2021 Jul 20. Epub 2021 Jul 20.

Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan, China.

The investigation of neural circuits is important for interpreting both healthy brain function and psychiatric disorders. Currently, the architecture of neural circuits is always investigated with fluorescent protein encoding neurotropic virus and ex vivo fluorescent imaging technology. However, it is difficult to obtain a whole-brain neural circuit connection in living animals, due to the limited fluorescent imaging depth. Read More

View Article and Full-Text PDF

-regulatory switches establish scale colour identity and pattern diversity in .

Elife 2021 Jul 19;10. Epub 2021 Jul 19.

Department of Zoology, University of Cambridge, Downing St., Cambridge, United Kingdom.

In butterflies, wing colour pattern diversity and scale types are controlled by a few genes of large effect that regulate colour pattern switches between morphs and species across a large mimetic radiation. One of these genes, , has been repeatedly associated with colour pattern evolution in butterflies. Here we carried out CRISPR knockouts in multiple species and show that is a major determinant of scale cell identity. Read More

View Article and Full-Text PDF

Presynaptic GABA receptor-mediated network excitation in the medial prefrontal cortex of Tsc2 mice.

Pflugers Arch 2021 Aug 19;473(8):1261-1271. Epub 2021 Jul 19.

Institute of Physiology, University Medical Center of the Johannes Gutenberg University Mainz, Duesbergweg 6, 55128, Mainz, Germany.

The TSC1 and TSC2 tumor suppressor genes control the activity of mechanistic target of rapamycin (mTOR) pathway. Elevated activity of this pathway in Tsc2 mouse model leads to reduction of postsynaptic GABA receptor-mediated inhibition and hyperexcitability in the medial prefrontal cortex (mPFC). In this study, we asked whether presynaptic GABA receptors (GABARs) can compensate this shift of hyperexcitability. Read More

View Article and Full-Text PDF

Targeting the Corticospinal Tract in Neonatal Rats with a Double-Viral Vector using Combined Brain and Spine Surgery.

J Vis Exp 2021 Jun 30(172). Epub 2021 Jun 30.

Shriners Hospitals Pediatric Research Center, Lewis Katz School of Medicine, Temple University.

Successfully tackling the obstacles that constrain research on neonatal rats is important for studying the differences in outcomes seen in pediatric spinal cord injuries (SCIs) compared to adult SCIs. In addition, reliably introducing therapies into the target cells of the central nervous system (CNS) can be challenging, and inaccuracies can compromise the efficacy of the study or therapy. This protocol combines viral vector technology with a novel surgical technique to accurately introduce gene therapies into neonatal rats at postnatal day 5. Read More

View Article and Full-Text PDF

Can Transcranial Direct Current Stimulation Enhance Functionality in Older Adults? A Systematic Review.

J Clin Med 2021 Jul 3;10(13). Epub 2021 Jul 3.

Toledo Physiotherapy Research Group (GIFTO), Faculty of Physiotherapy and Nursing, Castilla La Mancha University, 13001 Toledo, Spain.

Transcranial direct current stimulation (tDCS) is a non-invasive, easy to administer, well-tolerated, and safe technique capable of affecting brain excitability, both at the cortical and cerebellum levels. However, its effectiveness has not been sufficiently assessed in all population segments or clinical applications. This systematic review aimed at compiling and summarizing the currently available scientific evidence about the effect of tDCS on functionality in older adults over 60 years of age. Read More

View Article and Full-Text PDF

Navigated, Robot-Driven Laser Craniotomy for SEEG Application Using Optical Coherence Tomography in an Animal Model.

Front Robot AI 2021 30;8:695363. Epub 2021 Jun 30.

Department of Neurosurgery, Medical University of Vienna, Vienna, Austria.

We recently introduced a navigated, robot-driven laser beam craniotomy for use with stereoelectroencephalography (SEEG) applications. This method was intended to substitute the hand-held electric power drill in an study. The purpose of this non-recovery pilot study was to acquire data for the depth control unit of this laser device, to test the feasibility of cutting bone channels, and to assess dura perforation and possible cortex damage related to cold ablation. Read More

View Article and Full-Text PDF

Tension Suture Fixation of Olecranon Fractures.

JBJS Essent Surg Tech 2021 Apr-Jun;11(2). Epub 2021 Jun 3.

Wrightington Upper Limb Unit, Wigan, United Kingdom.

Background: Mayo type-IIA olecranon fractures are characterized by a transverse or short oblique fracture without articular comminution or ulnohumeral instability. Traditionally, these fractures are treated with a tension-band wiring technique. Despite good rates of fracture union, tension-band wiring is associated with a reoperation rate of 30% to 60%, usually for removal of prominent metalwork. Read More

View Article and Full-Text PDF

Neural mechanisms of foreign accent syndrome: Lesion and network analysis.

Neuroimage Clin 2021 Jul 8;31:102760. Epub 2021 Jul 8.

Department of Neurology and Stroke Medicine, Yokohama City University Graduate School of Medicine, 3-9 Fukuura, Kanazawa-ku, Yokohama, Kanagawa 236-0004, Japan. Electronic address:

Background: Foreign accent syndrome (FAS) is a rare acquired speech disorder wherein an individual's spoken accent is perceived as "foreign." Most reported cases involve left frontal brain lesions, but it is known that various other lesions can also cause FAS. To determine whether heterogeneous FAS-causing lesions are localized to a common functional speech network rather than to a single anatomical site, we employed a recently validated image analysis technique known as "lesion network mapping. Read More

View Article and Full-Text PDF

Exploring cortico-cortical interactions during action preparation by means of dual-coil transcranial magnetic stimulation: A systematic review.

Neurosci Biobehav Rev 2021 09 15;128:678-692. Epub 2021 Jul 15.

INSERM UMR1093-CAPS, Université Bourgogne Franche-Comté, UFR des Sciences du Sport, F-21000, Dijon, France. Electronic address:

Action preparation is characterized by a set of complex and distributed processes that occur in multiple brain areas. Interestingly, dual-coil transcranial magnetic stimulation (TMS) is a relevant technique to probe effective connectivity between cortical areas, with a high temporal resolution. In the current systematic review, we aimed at providing a detailed picture of the cortico-cortical interactions underlying action preparation focusing on dual-coil TMS studies. Read More

View Article and Full-Text PDF
September 2021

Characterising factors underlying praxis deficits in chronic left hemisphere stroke patients.

Cortex 2021 May 29;142:154-168. Epub 2021 May 29.

MRC Cognition and Brain Sciences Unit, University of Cambridge, Cambridge, UK.

Limb apraxia, a disorder of skilled action not consequent on primary motor or sensory deficits, has traditionally been defined according to errors patients make on neuropsychological tasks. Previous models of the disorder have failed to provide a unified account of patients' deficits, due to heterogeneity in the patients and tasks used. In this study we hypothesised that we may be able to map apraxic deficits onto principal components, some of which may be specific, whilst others may align with other cognitive disorders. Read More

View Article and Full-Text PDF

Scan Time Reduction in Intravoxel Incoherent Motion Diffusion-Weighted Imaging and Diffusion Kurtosis Imaging of the Abdominal Organs: Using a Simultaneous Multislice Technique With Different Acceleration Factors.

J Comput Assist Tomogr 2021 Jul 13. Epub 2021 Jul 13.

From the Department of Radiology Clinical Epidemiology and EBM Unit, Beijing Friendship Hospital, Capital Medical University MR Collaboration, Siemens Healthineers Ltd., Beijing, China MR Application, Siemens Healthineers Ltd., Guangzhou, China.

Objective: To investigate the feasibility of quantitative intravoxel incoherent motion (IVIM) and diffusion kurtosis imaging (DKI) analyses in the upper abdominal organs by simultaneous multislice diffusion-weighted imaging (SMS-DWI).

Subjects And Methods: In this prospective study, a total of 32 participants underwent conventional DWI (C-DWI) and SMS-DWI sequences with acceleration factors of 2 and 3 (SMS2-DWI and SMS3-DWI, respectively) in the upper abdomen with multiple b-values (0, 10, 20, 50, 80, 100, 150, 200, 500, 800, 1000, 1500, and 2000 seconds/mm2) on a 3 T system (MAGNETOM Prisma; Siemens Healthcare, Erlangen, Germany). Image quality and quantitatively measurements of apparent diffusion coefficient (ADC), true diffusion coefficient (D), pseudodiffusion coefficient (D*), perfusion fraction (f), mean kurtosis (MK), and mean apparent diffusivity (MD) for the liver, pancreas, kidney cortex and medulla, spleen, and erector spine muscle were compared between the 3 sequences. Read More

View Article and Full-Text PDF

MicroPET/CT assessment of neurochemical effects in the brain after long-term methylphenidate treatment in nonhuman primates.

Neurotoxicol Teratol 2021 Jul 12;87:107017. Epub 2021 Jul 12.

National Center for Toxicological Research, U.S. Food and Drug Administration, Jefferson, AR 72079, United States of America.

Methylphenidate (MPH) is a psychostimulant approved by the FDA to treatment Attention-Deficit Hyperactivity Disorder (ADHD). MPH is believed to exert its pharmacological effects via preferential blockade of the dopamine transporter (DAT) and the norepinephrine transporter (NET), resulting in increased monoamine levels in the synapse. We used a quantitative non-invasive PET imaging technique to study the effects of long-term methylphenidate use on the central nervous system (CNS). Read More

View Article and Full-Text PDF

Altered Spontaneous Glutamatergic and GABAergic Activity in the Peritumoral Cortex of Low-Grade Gliomas Presenting With History of Seizures.

Front Neurosci 2021 28;15:689769. Epub 2021 Jun 28.

Department of Biophysics, All India Institute of Medical Sciences, New Delhi, India.

The peritumoral regions of WHO grade II gliomas, like astrocytoma and oligodendroglioma, have been reported to show epileptiform activities. An imbalance of glutamatergic and GABAergic mechanisms is primarily responsible for the generation of epileptiform activities. Here we have compared the electrophysiological properties of pyramidal neurons in intraoperative peritumoral specimens obtained from glioma patients with (GS) and without (GN) a history of seizures at presentation. Read More

View Article and Full-Text PDF

Effect of combined yoga and transcranial direct current stimulation intervention on working memory and mindfulness.

J Integr Neurosci 2021 Jun;20(2):367-374

Department of Psychiatry, University of British Columbia, Non-Invasive Neurostimulation Therapies Laboratory, Vancouver, BC V6T 1Z4, Canada.

Transcranial direct stimulation, a non-invasive neurostimulation technique for modulating cortical excitability, and yoga have both respectively been shown to positively affect cognition. While preliminary research has shown that combined transcranial direct stimulation and meditation may have synergistic effects on mood and cognition, this was the first study to explore the combination of transcranial direct stimulation and yoga. Twenty-two healthy volunteers with a regular yoga practice were randomized to receive either active transcranial direct stimulation (anodal left, cathodal right dorsolateral prefrontal cortex) followed by yoga intervention or sham transcranial direct stimulation followed by yoga intervention a double-blind, cross-over design over two separate intervention days. Read More

View Article and Full-Text PDF