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https://www.readbyqxmd.com/read/27913590/control-of-spike-transfer-at-hippocampal-mossy-fiber-synapses-in-vivo-by-gabaa-and-gabab-receptor-mediated-inhibition
#1
Stefano Zucca, Marilena Griguoli, Meryl Malézieux, Noëlle Grosjean, Mario Carta, Christophe Mulle
: Despite extensive studies in hippocampal slices and incentive from computational theories, the synaptic mechanisms underlying information transfer at mossy fiber (mf) connections between the dentate gyrus (DG) and CA3 neurons in vivo are still elusive. Here we used an optogenetic approach in mice to selectively target and control the activity of DG granule cells (GCs) while performing whole cell and juxtacellular recordings of CA3 neurons in vivo In CA3 pyramidal cells (PCs), mf-CA3 synaptic responses consisted predominantly of an inhibitory postsynaptic potential (IPSP) at low stimulation frequency (0...
December 2, 2016: Journal of Neuroscience: the Official Journal of the Society for Neuroscience
https://www.readbyqxmd.com/read/27911754/cortical-control-of-spatial-resolution-by-vip-interneurons
#2
Inbal Ayzenshtat, Mahesh Miikael Karnani, Jesse Jackson, Rafael Yuste
: Neuronal tuning, defined by the degree of selectivity to a specific stimulus, is a hallmark of cortical computation. Understanding the role of GABAergic interneurons in shaping cortical tuning is now possible with the ability to manipulate interneuron classes selectively. Here, we show that interneurons expressing vasoactive intestinal polypeptide (VIP(+)) regulate the spatial frequency (SF) tuning of pyramidal neurons in mouse visual cortex. Using two-photon calcium imaging and optogenetic manipulations of VIP(+) cell activity, we found that activating VIP(+) cells elicited a stronger network response to stimuli of higher SFs, whereas suppressing VIP(+) cells resulted in a network response shift toward lower SFs...
November 9, 2016: Journal of Neuroscience: the Official Journal of the Society for Neuroscience
https://www.readbyqxmd.com/read/27894998/push-pull-and-feedback-mechanisms-can-align-signaling-system-outputs-with-inputs
#3
Steven S Andrews, William J Peria, Richard C Yu, Alejandro Colman-Lerner, Roger Brent
Many cell signaling systems, including the yeast pheromone response system, exhibit "dose-response alignment" (DoRA), in which output of one or more downstream steps closely matches the fraction of occupied receptors. DoRA can improve the fidelity of transmitted dose information. Here, we searched systematically for biochemical network topologies that produced DoRA. Most networks, including many containing feedback and feedforward loops, could not produce DoRA. However, networks including "push-pull" mechanisms, in which the active form of a signaling species stimulates downstream activity and the nominally inactive form reduces downstream activity, enabled perfect DoRA...
November 23, 2016: Cell Systems
https://www.readbyqxmd.com/read/27881971/familial-longevity-is-not-associated-with-major-differences-in-the-hypothalamic-pituitary-gonadal-axis-in-healthy-middle-aged-men
#4
Evie van der Spoel, Ferdinand Roelfsema, Steffy W Jansen, Abimbola A Akintola, Bart E Ballieux, Christa M Cobbaert, Gerard J Blauw, P Eline Slagboom, Rudi G J Westendorp, Hanno Pijl, Diana van Heemst
CONTEXT: A trade-off between fertility and longevity possibly exists. The association of the male hypothalamic-pituitary-gonadal (HPG) axis with familial longevity has not yet been investigated. OBJECTIVE: To study 24-h hormone concentration profiles of the HPG axis in men enriched for familial longevity and controls. DESIGN: We frequently sampled blood over 24 h in 10 healthy middle-aged male offspring of nonagenarian participants from the Leiden Longevity Study together with 10 male age-matched controls...
2016: Frontiers in Endocrinology
https://www.readbyqxmd.com/read/27857955/non-thermal-modulation-of-sudomotor-function-during-static-exercise-and-the-impact-of-intensity-and-muscle-mass-recruitment
#5
Christopher J Gordon, Joanne N Caldwell, Nigel A S Taylor
Aim: Static muscle activation elicits intensity-dependent, non-thermal sweating that is presumably controlled by feedforward (central command) mechanisms. However, it is currently unknown how the size of the recruited muscle mass interacts with that mechanism. To investigate the possible muscle-size dependency of that non-thermal sweating, the recruitment of two muscle groups of significantly different size was investigated in individuals within whom steady-state thermal sweating had been established and clamped...
April 2016: Temperature: Multidisciplinary Biomedical Journal
https://www.readbyqxmd.com/read/27849542/learning-inverse-rig-mappings-by-nonlinear-regression
#6
Daniel Holden, Jun Saito, Taku Komura
We present a framework to design inverse rig-functions - functions that map low level representations of a character's pose such as joint positions or surface geometry to the representation used by animators called the animation rig. Animators design scenes using an animation rig, a framework widely adopted in animation production which allows animators to design character poses and geometry via intuitive parameters and interfaces. Yet most state-of-the-art computer animation techniques control characters through raw, low level representations such as joint angles, joint positions, or vertex coordinates...
November 11, 2016: IEEE Transactions on Visualization and Computer Graphics
https://www.readbyqxmd.com/read/27835830/a-feed-forward-adaptive-canceller-to-reduce-the-occlusion-effect-in-hearing-aids
#7
Renata Coelho Borges, Márcio Holsbach Costa
Hearing aids are essential devices for social integration of hearing impaired people in order to improve their auditory perception. Recent studies have reported significant dissatisfaction factors that tend to reduce their daily use. The occlusion effect is one important source of complaints. This phenomenon stems from the partial or complete closure of the ventilation opening of the ear-mould, usually performed to prevent feedback effects in high-gain devices. This work presents a new adaptive active-noise-control system to reduce the occlusion effect in small- or unvented hearing aids...
October 18, 2016: Computers in Biology and Medicine
https://www.readbyqxmd.com/read/27835647/network-receptive-field-modeling-reveals-extensive-integration-and-multi-feature-selectivity-in-auditory-cortical-neurons
#8
Nicol S Harper, Oliver Schoppe, Ben D B Willmore, Zhanfeng Cui, Jan W H Schnupp, Andrew J King
Cortical sensory neurons are commonly characterized using the receptive field, the linear dependence of their response on the stimulus. In primary auditory cortex neurons can be characterized by their spectrotemporal receptive fields, the spectral and temporal features of a sound that linearly drive a neuron. However, receptive fields do not capture the fact that the response of a cortical neuron results from the complex nonlinear network in which it is embedded. By fitting a nonlinear feedforward network model (a network receptive field) to cortical responses to natural sounds, we reveal that primary auditory cortical neurons are sensitive over a substantially larger spectrotemporal domain than is seen in their standard spectrotemporal receptive fields...
November 2016: PLoS Computational Biology
https://www.readbyqxmd.com/read/27831933/aerodynamic-parameters-from-distributed-heterogeneous-cnt-hair-sensors-with-a-feedforward-neural-network
#9
Kaman Thapa Magar, Gregory W Reich, Corey Kondash, Keith Slinker, Alexander M Pankonien, Jeffery W Baur, Brian Smyers
Distributed arrays of artificial hair sensors have bio-like sensing capabilities to obtain spatial and temporal surface flow information which is an important aspect of an effective fly-by-feel system. The spatiotemporal surface flow measurement enables further exploration of additional flow features such as flow stagnation, separation, and reattachment points. Due to their inherent robustness and fault tolerant capability, distributed arrays of hair sensors are well equipped to assess the aerodynamic and flow states in adverse conditions...
November 10, 2016: Bioinspiration & Biomimetics
https://www.readbyqxmd.com/read/27828430/adaptive-illumination-based-on-direct-wavefront-sensing-in-a-light-sheet-fluorescence-microscope
#10
Dean Wilding, Paolo Pozzi, Oleg Soloviev, Gleb Vdovin, Michel Verhaegen
A methodology for the adaptive control and correction of phase aberrations in the illumination arm of a light-sheet fluorescence microscope has been developed. The method uses direct wavefront sensing on epi-fluorescent light to detect the aberration present in the sample. Using this signal, the aberrations in the illumination arm are subsequently corrected with a spatial light modulator in a feedforward mode. Adaptive correction, resulting in significant improvement in the axial resolution, has been demonstrated by imaging Tg(fli:GFP) zebrafish embryos...
October 31, 2016: Optics Express
https://www.readbyqxmd.com/read/27815363/stage-specific-timing-of-the-microrna-regulation-of-lin-28-by-the-heterochronic-gene-lin-14-in-caenorhabditis-elegans
#11
Jennifer Tsialikas, Mitchell A Romens, Allison Abbott, Eric G Moss
In normal development, the order and synchrony of diverse developmental events must be explicitly controlled. In the nematode Caenorhabditis elegans, the timing of larval events is regulated by hierarchy of proteins and microRNAs known as the heterochronic pathway. These regulators are organized in feedforward and feedback interactions to form a robust mechanism for specifying the timing and execution of cell fates at successive stages. One member of this pathway is the RNA binding protein LIN-28, which promotes pluripotency and cell fate decisions in successive stages...
November 4, 2016: Genetics
https://www.readbyqxmd.com/read/27807415/wavelet-entropy-and-directed-acyclic-graph-support-vector-machine-for-detection-of-patients-with-unilateral-hearing-loss-in-mri-scanning
#12
Shuihua Wang, Ming Yang, Sidan Du, Jiquan Yang, Bin Liu, Juan M Gorriz, Javier Ramírez, Ti-Fei Yuan, Yudong Zhang
Highlights We develop computer-aided diagnosis system for unilateral hearing loss detection in structural magnetic resonance imaging.Wavelet entropy is introduced to extract image global features from brain images. Directed acyclic graph is employed to endow support vector machine an ability to handle multi-class problems.The developed computer-aided diagnosis system achieves an overall accuracy of 95.1% for this three-class problem of differentiating left-sided and right-sided hearing loss from healthy controls...
2016: Frontiers in Computational Neuroscience
https://www.readbyqxmd.com/read/27784224/detection-of-unilateral-hearing-loss-by-stationary-wavelet-entropy
#13
Yudong Zhang, Deepak Ranjan Nayak, Ming Yang, Ying Shao, Bin Liu, Shuihua Wang
(Aim) Sensorineural hearing loss is correlated to massive neurological or psychiatric disease. (Materials) T1-weighted volumetric images were acquired from fourteen subjects with right-sided hearing loss (RHL), fifteen subjects with left-sided hearing loss (LHL), and 20 healthy controls (HC). (Method) We treat this a three-class classification problem: HC, LHL, and RHL. Stationary wavelet entropy was employed to extract global features from magnetic resonance images of each subject. Those stationary wavelet entropy features are used as input to a single-hidden layer feedforward neural-network classifier...
October 26, 2016: CNS & Neurological Disorders Drug Targets
https://www.readbyqxmd.com/read/27780044/evolution-of-biological-image-stabilization
#14
REVIEW
Ben J Hardcastle, Holger G Krapp
The use of vision to coordinate behavior requires an efficient control design that stabilizes the world on the retina or directs the gaze towards salient features in the surroundings. With a level gaze, visual processing tasks are simplified and behaviorally relevant features from the visual environment can be extracted. No matter how simple or sophisticated the eye design, mechanisms have evolved across phyla to stabilize gaze. In this review, we describe functional similarities in eyes and gaze stabilization reflexes, emphasizing their fundamental role in transforming sensory information into motor commands that support postural and locomotor control...
October 24, 2016: Current Biology: CB
https://www.readbyqxmd.com/read/27725086/an-excitatory-cortical-feedback-loop-gates-retinal-wave-transmission-in-rodent-thalamus
#15
Yasunobu Murata, Matthew T Colonnese
Spontaneous retinal waves are critical for the development of receptive fields in visual thalamus (LGN) and cortex (VC). Despite a detailed understanding of the circuit specializations in retina that generate waves, whether central circuit specializations also exist to control their propagation through visual pathways of the brain is unknown. Here we identify a developmentally transient, corticothalamic amplification of retinal drive to thalamus as a mechanism for retinal wave transmission in the infant rat brain...
October 11, 2016: ELife
https://www.readbyqxmd.com/read/27707978/impact-of-visual-corticostriatal-loop-disruption-on-neural-processing-within-the-parahippocampal-place-area
#16
Shahin Nasr, Herminia D Rosas
: The caudate nucleus is a part of the visual corticostriatal loop (VCSL), receiving input from different visual areas and projecting back to the same cortical areas via globus pallidus, substantia nigra, and thalamus. Despite perceptual and navigation impairments in patients with VCSL disruption due to caudate atrophy (e.g., Huntington's disease, HD), the relevance of the caudate nucleus and VCSL on cortical visual processing is not fully understood. In a series of fMRI experiments, we found that the caudate showed a stronger functional connection to parahippocampal place area (PPA) compared with adjacent regions (e...
October 5, 2016: Journal of Neuroscience: the Official Journal of the Society for Neuroscience
https://www.readbyqxmd.com/read/27696702/distinct-roles-of-immunoreceptor-tyrosine-based-motifs-in-immunosuppressive-indoleamine-2-3-dioxygenase-1
#17
Elisa Albini, Verdiana Rosini, Marco Gargaro, Giada Mondanelli, Maria L Belladonna, Maria Teresa Pallotta, Claudia Volpi, Francesca Fallarino, Antonio Macchiarulo, Cinzia Antognelli, Roberta Bianchi, Carmine Vacca, Paolo Puccetti, Ursula Grohmann, Ciriana Orabona
The enzyme indoleamine 2,3-dioxygenase 1 (IDO1) catalyses the initial, rate-limiting step in tryptophan (Trp) degradation, resulting in tryptophan starvation and the production of immunoregulatory kynurenines. IDO1's catalytic function has long been considered as the one mechanism responsible for IDO1-dependent immune suppression by dendritic cells (DCs), which are master regulators of the balance between immunity and tolerance. However, IDO1 also harbours immunoreceptor tyrosine-based inhibitory motifs, (ITIM1 and ITIM2), that, once phosphorylated, bind protein tyrosine phosphatases, (SHP-1 and SHP-2), and thus trigger an immunoregulatory signalling in DCs...
September 30, 2016: Journal of Cellular and Molecular Medicine
https://www.readbyqxmd.com/read/27680542/the-physiological-basis-and-measurement-of-heart-rate-variability-in-humans
#18
Adina E Draghici, J Andrew Taylor
Cardiovascular variabilities were recognized over 250 years ago, but only in the past 20 years has their apparent utility come to be appreciated. Technological advancement has allowed precise measurement and quantification of short-term cardiovascular fluctuations; however, our understanding of the integrated mechanisms which underlie these oscillations is inadequate for their widespread application. Both autonomic branches, the parasympathetic and sympathetic nervous system, are key determinants of the magnitude of these spontaneous cardiovascular fluctuations...
September 28, 2016: Journal of Physiological Anthropology
https://www.readbyqxmd.com/read/27669144/recruitment-of-inhibition-and-excitation-across-mouse-visual-cortex-depends-on-the-hierarchy-of-interconnecting-areas
#19
Rinaldo David D'Souza, Andrew Max Meier, Pawan Bista, Quanxin Wang, Andreas Burkhalter
Diverse features of sensory stimuli are selectively processed in distinct brain areas. The relative recruitment of inhibitory and excitatory neurons within an area controls the gain of neurons for appropriate stimulus coding. We examined how such a balance of inhibition and excitation is differentially recruited across multiple levels of a cortical hierarchy by mapping the locations and strengths of synaptic inputs to pyramidal and parvalbumin (PV)-expressing neurons in feedforward and feedback pathways interconnecting primary (V1) and two higher visual areas...
September 26, 2016: ELife
https://www.readbyqxmd.com/read/27662694/objective-model-selection-for-identifying-the-human-feedforward-response-in-manual-control
#20
Frank M Drop, Daan M Pool, Marinus M van Paassen, Max Mulder, Heinrich H Bulthoff
Realistic manual control tasks typically involve predictable target signals and random disturbances. The human controller (HC) is hypothesized to use a feedforward control strategy for target-following, in addition to feedback control for disturbance-rejection. Little is known about human feedforward control, partly because common system identification methods have difficulty in identifying whether, and (if so) how, the HC applies a feedforward strategy. In this paper, an identification procedure is presented that aims at an objective model selection for identifying the human feedforward response, using linear time-invariant autoregressive with exogenous input models...
September 19, 2016: IEEE Transactions on Cybernetics
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