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https://www.readbyqxmd.com/read/29330326/loss-of-balance-between-striatal-feedforward-inhibition-and-corticostriatal-excitation-leads-to-tremor
#1
Yael Oran, Izhar Bar-Gad
Fast spiking interneurons (FSIs) exert powerful inhibitory control over the striatum and are hypothesized to balance the massive excitatory cortical and thalamic input to this structure. We recorded neuronal activity in the dorsolateral striatum and globus pallidus (GP) concurrently with the detailed movement kinematics of freely behaving female rats prior to and following selective inhibition of FSI activity using IEM-1460 microinjections. The inhibition led to the appearance of episodic rest tremor in the body part that depended on the somatotopic location of the injection within the striatum...
January 12, 2018: Journal of Neuroscience: the Official Journal of the Society for Neuroscience
https://www.readbyqxmd.com/read/29329240/effective-data-driven-calibration-for-a-galvanometric-laser-scanning-system-using-binocular-stereo-vision
#2
Junchao Tu, Liyan Zhang
A new solution to the problem of galvanometric laser scanning (GLS) system calibration is presented. Under the machine learning framework, we build a single-hidden layer feedforward neural network (SLFN)to represent the GLS system, which takes the digital control signal at the drives of the GLS system as input and the space vector of the corresponding outgoing laser beam as output. The training data set is obtained with the aid of a moving mechanism and a binocular stereo system. The parameters of the SLFN are efficiently solved in a closed form by using extreme learning machine (ELM)...
January 12, 2018: Sensors
https://www.readbyqxmd.com/read/29317053/fear-of-movement-modulates-the-feedforward-motor-control-of-the-affected-limb-in-complex-regional-pain-syndrome-crps-a-single-case-study
#3
Michihiro Osumi, Masahiko Sumitani, Yuko Otake, Shu Morioka
Pain-related fear can exacerbate physical disability and pathological pain in complex regional pain syndrome (CRPS) patients. We conducted a kinematic analysis of grasping movements with a pediatric patient suffering from CRPS in an upper limb to investigate how pain-related fear affects motor control. Using a three-dimensional measurement system, we recorded the patient's movement while grasping three vertical bars of different diameters (thin, middle, thick) with the affected and intact hands. We analyzed the maximum grasp distance between the thumb and the index finger (MGD), the peak velocity of the grasp movement (PV), and the time required for the finger opening phase (TOP) and closing phase (TCP)...
January 2018: Medical Hypotheses
https://www.readbyqxmd.com/read/29311009/cortical-inhibitory-function-in-cervical-dystonia
#4
Christos Ganos, Elisa R Ferrè, Angela Marotta, Panagiotis Kassavetis, John Rothwell, Kailash P Bhatia, Patrick Haggard
OBJECTIVE: To assess the specificity of cortical inhibitory deficits in cervical dystonia patients. METHODS: A systematic test battery was developed to assess spatial and temporal aspects of cortical inhibition, in motor and somatosensory systems of the hand. We tested 17 cervical dystonia (CD) patients and 19 controls assessing somatosensory spatial inhibition (grating orientation test, interdigital feedforward subliminal inhibition), somatosensory temporal inhibition (temporal discrimination threshold, feedforward subliminal inhibition), motor spatial inhibition (surround inhibition), and motor temporal inhibition (short interval intracortical inhibition)...
December 1, 2017: Clinical Neurophysiology: Official Journal of the International Federation of Clinical Neurophysiology
https://www.readbyqxmd.com/read/29283112/bat-inspired-integrally-actuated-membrane-wings-with-leading-edge-sensing
#5
Stefano Buoso, Benjamin T Dickinson, Rafael Palacios
This paper presents a numerical investigation on the closed-loop performance of a two-dimensional actuated membrane wing with fixed supports. The proposed concept mimics aerodynamic sensing and actuation mechanisms found in bat wings to achieve robust outdoor flight: firstly, variable membrane tension, which is obtained in bats through skeleton articulation, is introduced through a dielectric-elastomer construction; secondly, leading-edge airflow sensing is achieved with bioinspired hair-like sensors. Numerical results from a coupled aero-electromechanical model show that this configuration can allow for the tracking of prescribed lift coefficient signals in the presence of disturbances from atmospheric gusts...
December 28, 2017: Bioinspiration & Biomimetics
https://www.readbyqxmd.com/read/29245032/atomic-force-microscopy-capable-of-vibration-isolation-with-low-stiffness-z-axis-actuation
#6
Shingo Ito, Georg Schitter
For high-resolution imaging without bulky external vibration isolation, this paper presents an atomic force microscope (AFM) capable of vibration isolation with its internal Z-axis (vertical) actuators moving the AFM probe. Lorentz actuators (voice coil actuators) are used for the Z-axis actuation, and flexures guiding the motion are designed to have a low stiffness between the mover and the base. The low stiffness enables a large Z-axis actuation of more than 700 µm and mechanically isolates the probe from floor vibrations at high frequencies...
December 5, 2017: Ultramicroscopy
https://www.readbyqxmd.com/read/29238299/the-htm-spatial-pooler-a-neocortical-algorithm-for-online-sparse-distributed-coding
#7
Yuwei Cui, Subutai Ahmad, Jeff Hawkins
Hierarchical temporal memory (HTM) provides a theoretical framework that models several key computational principles of the neocortex. In this paper, we analyze an important component of HTM, the HTM spatial pooler (SP). The SP models how neurons learn feedforward connections and form efficient representations of the input. It converts arbitrary binary input patterns into sparse distributed representations (SDRs) using a combination of competitive Hebbian learning rules and homeostatic excitability control...
2017: Frontiers in Computational Neuroscience
https://www.readbyqxmd.com/read/29204467/home-energy-management-hem-database-a-list-with-coded-attributes-of-308-devices-commercially-available-in-the-us
#8
Marco Pritoni, Rebecca Ford, Beth Karlin, Angela Sanguinetti
Policymakers worldwide are currently discussing whether to include home energy management (HEM) products in their portfolio of technologies to reduce carbon emissions and improve grid reliability. However, very little data is available about these products. Here we present the results of an extensive review including 308 HEM products available on the US market in 2015-2016. We gathered these data from publicly available sources such as vendor websites, online marketplaces and other vendor documents. A coding guide was developed iteratively during the data collection and utilized to classify the devices...
February 2018: Data in Brief
https://www.readbyqxmd.com/read/29199017/linear-integration-of-erk-activity-predominates-over-persistence-detection-in-fra-1-regulation
#9
Taryn E Gillies, Michael Pargett, Marta Minguet, Alex E Davies, John G Albeck
ERK signaling regulates the expression of target genes, but it is unclear how ERK activity dynamics are interpreted. Here, we investigate this question using simultaneous, live, single-cell imaging of two ERK activity reporters and expression of Fra-1, a target gene controlling epithelial cell identity. We find that Fra-1 is expressed in proportion to the amplitude and duration of ERK activity. In contrast to previous "persistence detector" and "selective filter" models in which Fra-1 expression only occurs when ERK activity persists beyond a threshold duration, our observations demonstrate that the network regulating Fra-1 expression integrates total ERK activity and responds to it linearly...
November 24, 2017: Cell Systems
https://www.readbyqxmd.com/read/29195342/grasping-force-hysteresis-compensation-of-a-piezoelectric-actuated-wire-clamp-with-a-modified-inverse-prandtl-ishlinskii-model
#10
Cunman Liang, Fujun Wang, Yanling Tian, Xingyu Zhao, Dawei Zhang
This paper presents the grasping force hysteresis compensation of a piezoelectric-actuated wire clamp with a modified hysteresis model. Considering dynamic characteristics of the wire clamp, a modified inverse Prandtl-Ishlinskii (MIPI) hysteresis model is developed to improve the hysteresis modeling accuracy. The proposed MIPI model is composed of a P-I model and a dynamic model which are connected in parallel. The proposed hysteresis model has the advantage of high modeling accuracy with a concise identification process, which means the step by step identification is not needed here...
November 2017: Review of Scientific Instruments
https://www.readbyqxmd.com/read/29164228/emg-driven-forward-dynamics-simulation-to-estimate-in-vivo-joint-contact-forces-during-normal-smooth-and-bouncy-gait
#11
Swithin Razu, Trent M Guess
This study leveraged data from the "Sixth Grand Challenge Competition to Predict in Vivo Knee Loads" to create a full-body musculoskeletal model that incorporates subject specific geometries of the right leg in order to concurrently predict knee contact forces, ligament forces, muscle forces, and ground contact forces. The objectives of this paper are twofold: First, to describe an electromyography (EMG)-driven modeling methodology to predict knee contact forces, and second to validate model predictions by evaluating the model predictions against known values for a patient with an instrumented total knee replacement (TKR) for three distinctly different gait styles (normal, smooth, and bouncy gait)...
November 21, 2017: Journal of Biomechanical Engineering
https://www.readbyqxmd.com/read/29162002/encoding-time-in-feedforward-trajectories-of-a-recurrent-neural-network-model
#12
N F Hardy, Dean V Buonomano
Brain activity evolves through time, creating trajectories of activity that underlie sensorimotor processing, behavior, and learning and memory. Therefore, understanding the temporal nature of neural dynamics is essential to understanding brain function and behavior. In vivo studies have demonstrated that sequential transient activation of neurons can encode time. However, it remains unclear whether these patterns emerge from feedforward network architectures or from recurrent networks and, furthermore, what role network structure plays in timing...
November 21, 2017: Neural Computation
https://www.readbyqxmd.com/read/29129925/the-neural-basis-of-homeostatic-and-anticipatory-thirst
#13
REVIEW
Claire Gizowski, Charles W Bourque
Water intake is one of the most basic physiological responses and is essential to sustain life. The perception of thirst has a critical role in controlling body fluid homeostasis and if neglected or dysregulated can lead to life-threatening pathologies. Clear evidence suggests that the perception of thirst occurs in higher-order centres, such as the anterior cingulate cortex (ACC) and insular cortex (IC), which receive information from midline thalamic relay nuclei. Multiple brain regions, notably circumventricular organs such as the organum vasculosum lamina terminalis (OVLT) and subfornical organ (SFO), monitor changes in blood osmolality, solute load and hormone circulation and are thought to orchestrate appropriate responses to maintain extracellular fluid near ideal set points by engaging the medial thalamic-ACC/IC network...
January 2018: Nature Reviews. Nephrology
https://www.readbyqxmd.com/read/29129638/an-attachment-independent-biochemical-timer-of-the-spindle-assembly-checkpoint
#14
Junbin Qian, Maria Adelaida García-Gimeno, Monique Beullens, Maria Giulia Manzione, Gerd Van der Hoeven, Juan Carlos Igual, Miguel Heredia, Pascual Sanz, Lendert Gelens, Mathieu Bollen
The spindle assembly checkpoint (SAC) generates a diffusible protein complex that prevents anaphase until all chromosomes are properly attached to spindle microtubules. A key step in SAC initiation is the recruitment of MAD1 to kinetochores, which is generally thought to be governed by the microtubule-kinetochore (MT-KT) attachment status. However, we demonstrate that the recruitment of MAD1 via BUB1, a conserved kinetochore receptor, is not affected by MT-KT interactions in human cells. Instead, BUB1:MAD1 interaction depends on BUB1 phosphorylation, which is controlled by a biochemical timer that integrates counteracting kinase and phosphatase effects on BUB1 into a pulse-generating incoherent feedforward loop...
November 16, 2017: Molecular Cell
https://www.readbyqxmd.com/read/29124504/variable-synaptic-strengths-controls-the-firing-rate-distribution-in-feedforward-neural-networks
#15
Cheng Ly, Gary Marsat
Heterogeneity of firing rate statistics is known to have severe consequences on neural coding. Recent experimental recordings in weakly electric fish indicate that the distribution-width of superficial pyramidal cell firing rates (trial- and time-averaged) in the electrosensory lateral line lobe (ELL) depends on the stimulus, and also that network inputs can mediate changes in the firing rate distribution across the population. We previously developed theoretical methods to understand how two attributes (synaptic and intrinsic heterogeneity) interact and alter the firing rate distribution in a population of integrate-and-fire neurons with random recurrent coupling...
November 10, 2017: Journal of Computational Neuroscience
https://www.readbyqxmd.com/read/29117549/prefrontal-cortex-drives-distinct-projection-neurons-in-the-basolateral-amygdala
#16
Laura M McGarry, Adam G Carter
The prefrontal cortex (PFC) regulates emotional behavior via top-down control of the basolateral amygdala (BLA). However, the influence of PFC inputs on the different projection pathways within the BLA remains largely unexplored. Here, we combine whole-cell recordings and optogenetics to study these cell-type specific connections in mouse BLA. We characterize PFC inputs onto three distinct populations of BLA neurons that project to the PFC, ventral hippocampus, or nucleus accumbens. We find that PFC-evoked synaptic responses are strongest at amygdala-cortical and amygdala-hippocampal neurons and much weaker at amygdala-striatal neurons...
November 7, 2017: Cell Reports
https://www.readbyqxmd.com/read/29028183/non-synaptic-signaling-from-cerebellar-climbing-fibers-modulates-golgi-cell-activity
#17
Angela K Nietz, Jada H Vaden, Luke T Coddington, Linda Overstreet-Wadiche, Jacques I Wadiche
Golgi cells are the principal inhibitory neurons at the input stage of the cerebellum, providing feedforward and feedback inhibition through mossy fiber and parallel fiber synapses. In vivo studies have shown that Golgi cell activity is regulated by climbing fiber stimulation, yet there is little functional or anatomical evidence for synapses between climbing fibers and Golgi cells. Here, we show that glutamate released from climbing fibers activates ionotropic and metabotropic receptors on Golgi cells through spillover-mediated transmission...
October 13, 2017: ELife
https://www.readbyqxmd.com/read/29025427/adaptive-hybrid-robotic-system-for-rehabilitation-of-reaching-movement-after-a-brain-injury-a-usability-study
#18
F Resquín, J Gonzalez-Vargas, J Ibáñez, F Brunetti, I Dimbwadyo, L Carrasco, S Alves, C Gonzalez-Alted, A Gomez-Blanco, J L Pons
BACKGROUND: Brain injury survivors often present upper-limb motor impairment affecting the execution of functional activities such as reaching. A currently active research line seeking to maximize upper-limb motor recovery after a brain injury, deals with the combined use of functional electrical stimulation (FES) and mechanical supporting devices, in what has been previously termed hybrid robotic systems. This study evaluates from the technical and clinical perspectives the usability of an integrated hybrid robotic system for the rehabilitation of upper-limb reaching movements after a brain lesion affecting the motor function...
October 12, 2017: Journal of Neuroengineering and Rehabilitation
https://www.readbyqxmd.com/read/28991792/automatic-control-of-the-effluent-turbidity-from-a-chemically-enhanced-primary-treatment-with-microsieving
#19
J Väänänen, S Memet, T Günther, M Lilja, M Cimbritz, J la Cour Jansen
For chemically enhanced primary treatment (CEPT) with microsieving, a feedback proportional integral controller combined with a feedforward compensator was used in large pilot scale to control effluent water turbidity to desired set points. The effluent water turbidity from the microsieve was maintained at various set points in the range 12-80 NTU basically independent for a number of studied variations in influent flow rate and influent wastewater compositions. Effluent turbidity was highly correlated with effluent chemical oxygen demand (COD)...
October 2017: Water Science and Technology: a Journal of the International Association on Water Pollution Research
https://www.readbyqxmd.com/read/28985154/rate-of-torque-development-and-feedforward-control-of-the-hip-and-knee-extensors-gender-differences
#20
Kristen M Stearns-Reider, Christopher M Powers
The purpose of this study was to determine whether women demonstrate decreased rate of torque development (RTD) of the hip and knee extensors and altered onset timing of the vastus lateralis and gluteus maximus during a drop-jump task when compared with men. On average, women demonstrated significantly lower normalized RTD of the hip extensors (women: 11.6 ± 1.3 MVT.s(-1), men: 13.1 ± 0.9 MVT.s(-1); p ≤ .01); however, there was no significant difference in knee extensor RTD. Women also demonstrated significantly earlier activation of their vastus lateralis (women: 206...
October 6, 2017: Journal of Motor Behavior
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