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https://www.readbyqxmd.com/read/29473693/prediction-of-memory-formation-based-on-absolute-electroencephalographic-phases-in-rhinal-cortex-and-hippocampus-outperforms-prediction-based-on-stimulus-related-phase-shifts
#1
Marlene Derner, Amirhossein Jahanbekam, Christian Bauckhage, Nikolai Axmacher, Juergen Fell
Absolute (i.e. measured) rhinal and hippocampal phase values are predictive for memory formation. It has been an open question, whether the capability of mediotemporal structures to react to stimulus presentation with phase shifts may be similarly indicative of successful memory formation. We analyzed data from 27 epilepsy patients implanted with depth electrodes in the hippocampus and entorhinal cortex, who performed a continuous word recognition task. Electroencephalographic (EEG) phase information related to the first presentation of repeatedly presented words was used for prediction of subsequent remembering versus forgetting applying a support vector machine...
February 23, 2018: European Journal of Neuroscience
https://www.readbyqxmd.com/read/29473543/creating-virtual-electrodes-with-two-dimensional-current-steering
#2
Thomas C Spencer, James B Fallon, Mohit N Shivdasani
Current steering techniques have shown promise in retinal prostheses as a way to increase the number of distinct percepts elicitable without increasing the number of implanted electrodes. Previously, it has been shown that 'virtual' electrodes can be created between simultaneously stimulated electrode pairs, producing unique cortical response patterns. This study investigated whether virtual electrodes could be created using two-dimensional current steering, and whether these virtual electrodes can produce cortical responses with predictable spatial characteristics...
February 23, 2018: Journal of Neural Engineering
https://www.readbyqxmd.com/read/29467602/feature-selection-methods-for-robust-decoding-of-finger-movements-in-a-non-human-primate
#3
Subash Padmanaban, Justin Baker, Bradley Greger
Objective: The performance of machine learning algorithms used for neural decoding of dexterous tasks may be impeded due to problems arising when dealing with high-dimensional data. The objective of feature selection algorithms is to choose a near-optimal subset of features from the original feature space to improve the performance of the decoding algorithm. The aim of our study was to compare the effects of four feature selection techniques, Wilcoxon signed-rank test, Relative Importance, Principal Component Analysis (PCA), and Mutual Information Maximization on SVM classification performance for a dexterous decoding task...
2018: Frontiers in Neuroscience
https://www.readbyqxmd.com/read/29449086/progress-in-the-use-of-dental-pulp-stem-cells-in-regenerative-medicine
#4
REVIEW
Eduardo Anitua, María Troya, Mar Zalduendo
The field of tissue engineering is emerging as a multidisciplinary area with promising potential for regenerating new tissues and organs. This approach requires the involvement of three essential components: stem cells, scaffolds and growth factors. To date, dental pulp stem cells have received special attention because they represent a readily accessible source of stem cells. Their high plasticity and multipotential capacity to differentiate into a large array of tissues can be explained by its neural crest origin, which supports applications beyond the scope of oral tissues...
February 12, 2018: Cytotherapy
https://www.readbyqxmd.com/read/29447794/plasticity-after-pediatric-cochlear-implantation-implication-from-changes-in-peripheral-plasma-level-of-bdnf-and-auditory-nerve-responses
#5
Razieh Alemi, Masoud Motassadi Zarandy, Mohammad Taghi Joghataei, Ali Eftekharian, Mohammad Reza Zarrindast, Nasim Vousooghi
INTRODUCTION: Sensory neural hearing loss could lead to some structural and physiological changes in the auditory pathways, such as alteration in the expression of neurotrophins. These factors, especially Brain-Derived Neurotrophic Factor (BDNF), play an important role in synaptic functions and experience-related plasticity. Restoring cochlear function after hearing loss is possible through cochlear implantation (CI). Evaluation of the blood concentration changes of neurotrophins as prerequisites of plasticity could help scientists to determine the prognosis of CI as in the candidacy procedure or enhancing prosthesis function by adding the exact needed amount of BDNF to the electrode array...
February 2018: International Journal of Pediatric Otorhinolaryngology
https://www.readbyqxmd.com/read/29442553/phase-reorganization-leads-to-transient-%C3%AE-lfp-spatial-wave-patterns-in-motor-cortex-during-steady-state-movement-preparation
#6
Michael Everett Rule, Carlos E Vargas-Irwin, John P Donoghue, Wilson Truccolo
Previous studies on the origin and properties of spatial patterns in motor cortex beta local field potential (β-LFP) oscillations have focused on planar traveling waves. However, it is unclear (a) whether β-LFP waves are limited to plane waves, or even (b) whether they are propagating waves of excito-excitatory activity, i.e. primarily traveling waves in excitable media; they could reflect, instead, reorganization in the relative phases of transient oscillations at different spatial sites. We addressed these two problems in β-LFPs recorded via microelectrode arrays implanted in three adjacent motor-cortex areas of non-human primates during steady-state movement preparation...
February 14, 2018: Journal of Neurophysiology
https://www.readbyqxmd.com/read/29442363/increased-neuronal-synchrony-prepares-mesial-temporal-networks-for-seizures-of-neocortical-origin
#7
Amrit Misra, Xianda Long, Michael R Sperling, Ashwini D Sharan, Karen A Moxon
OBJECTIVE: To gain understanding of the neuronal mechanisms underlying regional seizure spread, the impact of regional synchrony between seizure focus and downstream networks on neuronal activity during the transition to seizure in those downstream networks was assessed. METHODS: Seven patients undergoing diagnostic intracranial electroencephalographic studies for surgical resection of epileptogenic regions were implanted with subdural clinical electrodes into the cortex (site of seizure initiation) and mesial temporal lobe (MTL) structures (downstream) as well as microwires into MTL...
February 14, 2018: Epilepsia
https://www.readbyqxmd.com/read/29432117/closed-loop-continuous-hand-control-via-chronic-recording-of-regenerative-peripheral-nerve-interfaces
#8
Philip P Vu, Zachary T Irwin, Autumn J Bullard, Shoshana W Ambani, Ian C Sando, Melanie G Urbanchek, Paul S Cederna, Cynthia A Chestek
Loss of the upper limb imposes a devastating interruption to everyday life. Full restoration of natural arm control requires the ability to simultaneously control multiple degrees of freedom of the prosthetic arm and maintain that control over an extended period of time. Current clinically available myoelectric prostheses do not provide simultaneous control or consistency for transradial amputees. To address this issue, we have implemented a standard Kalman filter for continuous hand control using intramuscular electromyography (EMG) from both regenerative peripheral nerve interfaces (RPNI) and an intact muscle within non-human primates...
February 2018: IEEE Transactions on Neural Systems and Rehabilitation Engineering
https://www.readbyqxmd.com/read/29432110/the-cochlear-implant-eeg-artifact-recorded-from-an-artificial-brain-for-complex-acoustic-stimuli
#9
Luise Wagner, Natasha Maurits, Bert Maat, Deniz Baskent, Anita E Wagner
Electroencephalographic (EEG) recordings provide objective estimates of listeners' cortical processing of sounds and of the status of their speech perception system. For profoundly deaf listeners with cochlear implants (CIs), the applications of EEG are limited because the device adds electric artifacts to the recordings. This restricts the possibilities for the neural-based metrics of speech processing by CI users, for instance to gauge cortical reorganization due to individual's hearing loss history. This paper describes the characteristics of the CI artifact as recorded with an artificial head substitute, and reports how the artifact is affected by the properties of the acoustical input signal versus the settings of the device...
February 2018: IEEE Transactions on Neural Systems and Rehabilitation Engineering
https://www.readbyqxmd.com/read/29425906/effects-of-vagal-neuromodulation-on-feeding-behavior
#10
Nicole A Pelot, Warren M Grill
Implanted vagus nerve stimulation (VNS) for obesity was recently approved by the FDA. However, its efficacy and mechanisms of action remain unclear. Herein, we synthesize clinical and preclinical effects of VNS on feeding behavior and energy balance and discuss engineering considerations for understanding and improving the therapy. Clinical cervical VNS (≤30 Hz) to treat epilepsy or depression has produced mixed effects on weight loss as a side effect, albeit in uncontrolled, retrospective studies. Conversely, preclinical studies (cervical and subdiaphragmatic VNS) mostly report decreased food intake and either decreased weight gain or weight loss...
February 6, 2018: Brain Research
https://www.readbyqxmd.com/read/29423457/recent-advances-in-neural-electrode-tissue-interfaces
#11
Kevin Woeppel, Qianru Yang, Xinyan Tracy Cui
Neurotechnology is facing an exponential growth in the recent decades. Neural electrode-tissue interface research has been well recognized as an instrumental component of neurotechnology development. While satisfactory long-term performance was demonstrated in some applications, such as cochlear implants and deep brain stimulators, more advanced neural electrode devices requiring higher resolution for single unit recording or microstimulation still face significant challenges in reliability and longevity. In this article, we review the most recent findings that contribute to our current understanding of the sources of poor reliability and longevity in neural recording or stimulation, including the material failure, biological tissue response and the interplay between the two...
December 2017: Current Opinion in Biomedical Engineering
https://www.readbyqxmd.com/read/29421549/unique-electrophysiological-and-impedance-signatures-between-encapsulation-types-an-analysis-of-biological-utah-array-failure-and-benefit-of-a-biomimetic-coating-in-a-rat-model
#12
Patrick A Cody, James R Eles, Carl F Lagenaur, Takashi D Y Kozai, X Tracy Cui
Intracortical microelectrode arrays, especially the Utah array, remain the most common choice for obtaining high dimensional recordings of spiking neural activity for brain computer interface and basic neuroscience research. Despite the widespread use and established design, mechanical, material and biological challenges persist that contribute to a steady decline in recording performance (as evidenced by both diminished signal amplitude and recorded cell population over time) or outright array failure. Device implantation injury causes acute cell death and activation of inflammatory microglia and astrocytes that leads to a chronic neurodegeneration and inflammatory glial aggregation around the electrode shanks and often times fibrous tissue growth above the pia along the bed of the array within the meninges...
January 31, 2018: Biomaterials
https://www.readbyqxmd.com/read/29421337/role-of-d1-and-d2-like-dopaminergic-receptors-in-the-nucleus-accumbens-in-modulation-of-formalin-induced-orofacial-pain-involvement-of-lateral-hypothalamus
#13
Iman Shafiei, Mahsaneh Vatankhah, Leila Zarepour, Somayeh Ezzatpanah, Abbas Haghparast
The role of dopaminergic system in modulation of formalin-induced orofacial nociception has been established. The present study aims to investigate the role of dopaminergic receptors in the nucleus accumbens (NAc) in modulation of nociceptive responses induced by formalin injection in the orofacial region. One hundred and six male Wistar rats were unilaterally implanted with two cannulae into the lateral hypothalamus (LH) and NAc. Intra-LH microinjection of carbachol, a cholinergic receptor agonist, was done 5min after intra-accumbal administration of different doses of SCH23390 (D1-like receptor antagonist) or sulpiride (D2-like receptor antagonist)...
January 29, 2018: Physiology & Behavior
https://www.readbyqxmd.com/read/29414094/a-silicon-based-neural-probe-with-densely-packed-low-impedance-titanium-nitride-microelectrodes-for-ultrahigh-resolution-in-vivo-recordings
#14
Richárd Fiáth, Bogdan Cristian Raducanu, Silke Musa, Alexandru Andrei, Carolina Mora Lopez, Chris van Hoof, Patrick Ruther, Arno Aarts, Domonkos Horváth, István Ulbert
In this study, we developed and validated a single-shank silicon-based neural probe with 128 closely-packed microelectrodes suitable for high-resolution extracellular recordings. The 8-mm-long, 100-µm-wide and 50-µm-thick implantable shank of the probe fabricated using a 0.13-µm complementary metal-oxide-semiconductor (CMOS) metallization technology contains square-shaped (20 × 20 µm2), low-impedance (~ 50 kΩ at 1 kHz) recording sites made of rough and porous titanium nitride which are arranged in a 32 × 4 dense array with an inter-electrode pitch of 22...
January 31, 2018: Biosensors & Bioelectronics
https://www.readbyqxmd.com/read/29412526/-obsessive-compulsive-disorder-and-deep-brain-stimulation-a-future-so-close
#15
João Flores Alves Dos Santos, Paul Krack, Shahan Momjian, Guido Bondolfi, Luc Mallet
The obsessive compulsive disorder (OCD) is a psychiatric disorder with a high prevalence (2‑3 %), frequently causing a disabling condition. Drug and psychotherapeutic treatment is generally effective. However about 1/3 of the patients are treatment-resistant, suffering from chronic psychological distress with important sociofunctional repercussions. The identification of dysfunctional neural networks in this disease opens the door to the use of neuromodulation techniques, as deep brain stimulation (DBS)...
February 7, 2018: Revue Médicale Suisse
https://www.readbyqxmd.com/read/29408391/single-injection-ex-ovo-transplantation-method-for-broad-spinal-cord-engraftment-of-human-pluripotent-stem-cell-derived-motor-neurons
#16
Maria C Estevez-Silva, Akshitha Sreeram, Stephanie Cuskey, Nikolai Fedorchak, Nisha Iyer, Randolph S Ashton
BACKGROUND: Transplantation of human pluripotent stem cell (hPSC)-derived neurons into chick embryos is an established preliminary assay to evaluate engraftment potential. Yet, with recent advances in deriving diverse human neuronal subtypes, optimizing and standardizing such transplantation methodology for specific subtypes at their correlated anatomical sites is still required. NEW METHOD: We determined the optimal stage of hPSC-derived motor neuron (hMN) differentiation for ex ovo transplantation, and developed a single injection protocol that implants hMNs throughout the spinal cord enabling broad regional engraftment possibilities...
February 3, 2018: Journal of Neuroscience Methods
https://www.readbyqxmd.com/read/29405776/the-safe-use-of-long-screws-in-l5-s1-stand-alone-anterior-interbody-fusion-for-olisthesis-cases
#17
Matthias A König, Michael P Grevitt, Nasir A Quraishi, Bronek M Boszczyk
BACKGROUND: Stand-alone anterior interbody fusion (STALIF) with poly-ether-ether-ketone (PEEK) cages could offer a treatment option in olisthesis cases. The fixation of the PEEK-cage at the L5/S1 inferior endplate with long divergent screws however might endanger neural sacral structures, especially the S1 nerve root. If shorter screws are used, the achieved bony purchase might not be sufficient to resist the pull out and shear forces at the lumbosacral junction. The aim of the present investigation was to evaluate the use of long screws in PEEK-cages for olisthesis cases at the L5/S1 segment and its neurological complications...
February 6, 2018: British Journal of Neurosurgery
https://www.readbyqxmd.com/read/29402703/tibial-nerve-stimulation-to-drive-genital-sexual-arousal-in-an-anesthetized-female-rat
#18
Lauren L Zimmerman, Indie C Rice, Mitchell B Berger, Tim M Bruns
BACKGROUND: There is clinical evidence that percutaneous tibial nerve stimulation can positively benefit women with female sexual interest/arousal disorder, yet no studies have explored the potential mechanisms further. AIM: To investigate the effect of tibial nerve stimulation on vaginal blood perfusion (VBP) in an anesthetized rat model. METHODS: 16 ketamine-anesthetized rats were surgically implanted with a nerve cuff electrode on 1 tibial nerve...
February 3, 2018: Journal of Sexual Medicine
https://www.readbyqxmd.com/read/29401502/attenuation-of-reactive-gliosis-in-stroke-injured-mouse-brain-does-not-affect-neurogenesis-from-grafted-human-ipsc-derived-neural-progenitors
#19
Cecilia Laterza, Naomi Uoshima, Daniel Tornero, Ulrika Wilhelmsson, Anna Stokowska, Ruimin Ge, Milos Pekny, Olle Lindvall, Zaal Kokaia
Induced pluripotent stem cells (iPSCs) or their progeny, derived from human somatic cells, can give rise to functional improvements after intracerebral transplantation in animal models of stroke. Previous studies have indicated that reactive gliosis, which is associated with stroke, inhibits neurogenesis from both endogenous and grafted neural stem/progenitor cells (NSPCs) of rodent origin. Here we have assessed whether reactive astrocytes affect the fate of human iPSC-derived NSPCs transplanted into stroke-injured brain...
2018: PloS One
https://www.readbyqxmd.com/read/29388356/advances-in-carbon-nanotubes-hydrogel-hybrids-in-nanomedicine-for-therapeutics
#20
REVIEW
Arti Vashist, Ajeet Kaushik, Atul Vashist, Vidya Sagar, Anujit Ghosal, Y K Gupta, Sharif Ahmad, Madhavan Nair
In spite of significant advancement in hydrogel technology, low mechanical strength and lack of electrical conductivity have limited their next-level biomedical applications for skeletal muscles, cardiac and neural cells. Host-guest chemistry based hybrid nanocomposites systems have gained attention as they completely overcome these pitfalls and generate bioscaffolds with tunable electrical and mechanical characteristics. In recent years, carbon nanotube (CNT)-based hybrid hydrogels have emerged as innovative candidates with diverse applications in regenerative medicines, tissue engineering, drug delivery devices, implantable devices, biosensing, and biorobotics...
February 1, 2018: Advanced Healthcare Materials
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