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https://www.readbyqxmd.com/read/28100654/dissociation-between-sustained-single-neuron-spiking-%C3%AE-rhythmicity-and-transient-%C3%AE-lfp-oscillations-in-primate-motor-cortex
#1
Michael Everett Rule, Carlos E Vargas-Irwin, John P Donoghue, Wilson Truccolo
Determining the relationship between single-neuron spiking and transient (~20 Hz) beta local field potential (β-LFP) oscillations is an important step for understanding the role of these oscillations in motor cortex. We show that while motor cortex firing rates and beta spiking rhythmicity remain sustained during steady-state movement preparation periods, β-LFP oscillations emerge, in contrast, as short transient events. Single-neuron mean firing rates within and outside transient β-LFP events showed no differences, and no consistent correlation was found between the beta oscillations' amplitude and firing rates, as was the case for movement and visual-cue related β-LFP suppression...
January 18, 2017: Journal of Neurophysiology
https://www.readbyqxmd.com/read/28088666/vocal-emotion-decoding-in-the-subthalamic-nucleus-an-intracranial-erp-study-in-parkinson-s-disease
#2
Julie Péron, Olivier Renaud, Claire Haegelen, Lucas Tamarit, Valérie Milesi, Jean-François Houvenaghel, Thibaut Dondaine, Marc Vérin, Paul Sauleau, Didier Grandjean
Using intracranial local field potential (LFP) recordings in patients with Parkinson's disease (PD) undergoing deep brain stimulation (DBS), we explored the electrophysiological activity of the subthalamic nucleus (STN) in response to emotional stimuli in the auditory modality. Previous studies focused on the influence of visual stimuli. To this end, we recorded LFPs within the STN in response to angry, happy, and neutral prosodies in 13 patients with PD who had just undergone implantation of DBS electrodes...
January 12, 2017: Brain and Language
https://www.readbyqxmd.com/read/28087359/the-effect-of-nmda-r-antagonism-on-simultaneously-acquired-local-field-potentials-and-tissue-oxygen-levels-in-the-brains-of-freely-moving-rats
#3
John Kealy, Sean Commins, John P Lowry
Non-competitive NMDA receptor antagonists are known to induce psychosis-like symptoms in rodents. Administration of such compounds cause behavioural effects such as memory impairment and hyperlocomotion. Additionally, drugs such as phencyclidine (PCP), ketamine and MK-801 all cause distinctive increases in striatal local field potential (LFP) in the high frequency oscillation (HFO) band in the power spectrum (140-180 Hz). Amperometric sensors provide a means to measure tissue oxygen (tO2; a BOLD-like signal) in the brains of freely-moving rats while simultaneously acquiring LFP using the same electrode...
January 11, 2017: Neuropharmacology
https://www.readbyqxmd.com/read/28077288/micro-endoscopic-system-for-functional-assessment-of-neural-circuits-in-deep-brain-regions-simultaneous-optical-and-electrical-recordings-of-auditory-responses-in-mouse-s-inferior-colliculus
#4
Hidetaka Yashiro, Ichiro Nakahara, Kazuo Funabiki, Hiroshi Riquimaroux
In vivo Ca(2+) imaging is a powerful method for the functional assessment of neural circuits. Although multi-photon excitation fluorescence microscopy has been widely used, observation of circuits in deep brain regions remains challenging. Recently, observing these deep regions has become possible via an endoscope consisting of an optical fiber bundle or gradient-index lens. We have designed a micro-endoscope system that enables simultaneous optical recording of fluorescence and electrical recording of neural activity...
January 7, 2017: Neuroscience Research
https://www.readbyqxmd.com/read/28074856/local-field-potentials-primarily-reflect-inhibitory-neuron-activity-in-human-and-monkey-cortex
#5
Bartosz Teleńczuk, Nima Dehghani, Michel Le Van Quyen, Sydney S Cash, Eric Halgren, Nicholas G Hatsopoulos, Alain Destexhe
The local field potential (LFP) is generated by large populations of neurons, but unitary contribution of spiking neurons to LFP is not well characterised. We investigated this contribution in multi-electrode array recordings from human and monkey neocortex by examining the spike-triggered LFP average (st-LFP). The resulting st-LFPs were dominated by broad spatio-temporal components due to ongoing activity, synaptic inputs and recurrent connectivity. To reduce the spatial reach of the st-LFP and observe the local field related to a single spike we applied a spatial filter, whose weights were adapted to the covariance of ongoing LFP...
January 11, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28069927/impact-of-altered-cholinergic-tones-on-the-neurovascular-coupling-response-to-whisker-stimulation
#6
Clotilde Lecrux, Claire H Sandoe, Sujaya Neupane, Pascal Kropf, Xavier Toussay, Xin-Kang Tong, María Lacalle-Aurioles, Amir Shmuel, Edith Hamel
Brain imaging techniques that use vascular signals to map changes in neuronal activity rely on the coupling between electrophysiology and hemodynamics, a phenomenon referred to "neurovascular coupling" (NVC). It is unknown whether this relationship remains reliable under altered brain states associated to acetylcholine (ACh) levels, such as attention and arousal, and in pathological conditions like Alzheimer's disease. We therefore assessed the effects of varying ACh tone on whisker evoked-NVC responses in rat barrel cortex, measured by cerebral blood flow (CBF) and neurophysiological recordings (local field potentials, LFPs)...
January 9, 2017: Journal of Neuroscience: the Official Journal of the Society for Neuroscience
https://www.readbyqxmd.com/read/28047631/we-fg-206-04-comprehensive-evaluation-of-left-ventricular-lv-filling-and-ejection-using-high-frame-rate-cine-mr-imaging-key-technical-and-methodological-requirements
#7
J Zhang, B Cheong, A Pednekar, C Arena, D Dees, R Muthupillai
PURPOSE: Unlike echocardiography which can quantify both LV filling and ejection, cine steady state free precession sequence (SSFP)-despite its high intrinsic signal and contrast to noise ratio, accuracy and precision of volume measurements-, is mostly relegated to quantifying LV ejection. The steady-state requirement typically constrains SSFP sequence to a breathhold (and limited temporal resolution). We describe: (a) free breathing cine SSFP approach that meets the SS requirement allowing high frame rate acquisition, (b) two MRI indices based on time-LV volume (TV) change during filling and compare against echocardiagraphic diastolic index (E/A ratio), and (c) evaluate the effect of temporal resolution on: LV volumes; ejection and filling rates; and normalized indices of systolic and diastolic function...
June 2016: Medical Physics
https://www.readbyqxmd.com/read/28031400/spinal-cord-direct-current-stimulation-differentially-modulates-neuronal-activity-in-the-dorsal-and-ventral-spinal-cord
#8
Weiguo Song, John H Martin
Spinal cord direct current stimulation (sDCS) has the potential for promoting motor function after injury through its modulatory actions on sensory processing, reflex functions, the motor cortex (M1) motor map, and motor output. Here we addressed systems-level mechanisms underlying sDCS neuromodulation of spinal circuits activated by M1 and peripheral forelimb electrical stimulation in anesthetized healthy rats. We determined the effects of cathodal and anodal sDCS (c- and a-sDCS) on local field potentials (LFP) and single-unit activity recorded at 32 sites simultaneously within the 6th cervical segment using a silicon multi-electrode array...
December 28, 2016: Journal of Neurophysiology
https://www.readbyqxmd.com/read/28029630/design-of-a-closed-loop-bidirectional-brain-machine-interface-system-with-energy-efficient-neural-feature-extraction-and-pid-control
#9
Xilin Liu, Milin Zhang, Andrew G Richardson, Timothy H Lucas, Jan Van der Spiegel
This paper presents a bidirectional brain machine interface (BMI) microsystem designed for closed-loop neuroscience research, especially experiments in freely behaving animals. The system-on-chip (SoC) consists of 16-channel neural recording front-ends, neural feature extraction units, 16-channel programmable neural stimulator back-ends, in-channel programmable closed-loop controllers, global analog-digital converters (ADC), and peripheral circuits. The proposed neural feature extraction units includes 1) an ultra low-power neural energy extraction unit enabling a 64-step natural logarithmic domain frequency tuning, and 2) a current-mode action potential (AP) detection unit with time-amplitude window discriminator...
December 16, 2016: IEEE Transactions on Biomedical Circuits and Systems
https://www.readbyqxmd.com/read/28018180/local-field-potentials-myths-and-misunderstandings
#10
REVIEW
Oscar Herreras
The intracerebral local field potential (LFP) is a measure of brain activity that reflects the highly dynamic flow of information across neural networks. This is a composite signal that receives contributions from multiple neural sources, yet interpreting its nature and significance may be hindered by several confounding factors and technical limitations. By and large, the main factor defining the amplitude of LFPs is the geometry of the current sources, over and above the degree of synchronization or the properties of the media...
2016: Frontiers in Neural Circuits
https://www.readbyqxmd.com/read/28017962/sirt1-plays-a-neuroprotective-role-in-traumatic-brain-injury-in-rats-via-inhibiting-the-p38-mapk-pathway
#11
Hong Yang, Zheng-Tao Gu, Li Li, Mac Maegele, Bi-Ying Zhou, Feng Li, Ming Zhao, Ke-Sen Zhao
Traumatic brain injury (TBI) is a major cause of disability and death in patients who experience a traumatic injury. Mitochondrial dysfunction is one of the main factors contributing to secondary injury in TBI-associated brain damage. Evidence of compromised mitochondrial function after TBI has been, but the molecular mechanisms underlying the pathogenesis of TBI are not well understood. Silent information regulator family protein 1 (SIRT1), a member of the NAD(+)-dependent protein deacetylases, has been shown to exhibit neuroprotective activities in animal models of various pathologies, including ischemic brain injury, subarachnoid hemorrhage and several neurodegenerative diseases...
December 26, 2016: Acta Pharmacologica Sinica
https://www.readbyqxmd.com/read/28007587/astrocytic-gap-junction-blockade-markedly-increases-extracellular-potassium-without-causing-seizures-in-the-mouse-neocortex
#12
Paolo Bazzigaluppi, Iliya Weisspapir, Bojana Stefanovic, Luc Leybaert, Peter L Carlen
Extracellular potassium concentration, [K(+)]o, is a major determinant of neuronal excitability. In the healthy brain, [K(+)]o levels are tightly controlled. During seizures, [K(+)]o increases up to 15mM and is thought to cause seizures due to its depolarizing effect. Although astrocytes have been suggested to play a key role in the redistribution (or spatial buffering) of excess K(+) through Connexin-43 (Cx43)-based Gap Junctions (GJs), the relation between this dynamic regulatory process and seizure generation remains unknown...
December 19, 2016: Neurobiology of Disease
https://www.readbyqxmd.com/read/27999534/striatal-dopaminergic-innervation-regulates-subthalamic-beta-oscillations-and-cortical-subcortical-coupling-during-movements-preliminary-evidence-in-subjects-with-parkinson-s-disease
#13
Andrea Canessa, Nicolò G Pozzi, Gabriele Arnulfo, Joachim Brumberg, Martin M Reich, Gianni Pezzoli, Maria F Ghilardi, Cordula Matthies, Frank Steigerwald, Jens Volkmann, Ioannis U Isaias
Activation of the basal ganglia has been shown during the preparation and execution of movement. However, the functional interaction of cortical and subcortical brain areas during movement and the relative contribution of dopaminergic striatal innervation remains unclear. We recorded local field potential (LFP) activity from the subthalamic nucleus (STN) and high-density electroencephalography (EEG) signals in four patients with Parkinson's disease (PD) off dopaminergic medication during a multi-joint motor task performed with their dominant and non-dominant hand...
2016: Frontiers in Human Neuroscience
https://www.readbyqxmd.com/read/27998779/systemic-blood-pressure-alters-cortical-blood-flow-and-neurovascular-coupling-during-nociceptive-processing-in-the-primary-somatosensory-cortex-of-the-rat
#14
Sae Uchida, Suzie Bois, Jean-Paul Guillemot, Hugues Leblond, Mathieu Piché
Inference on nociceptive and pain-related processes from functional magnetic resonance imaging is made with the assumption that the coupling of neuronal activity and cerebral hemodynamic changes is stable. However, since nociceptive stimulation is associated with increases in systemic arterial pressure, it is essential to determine whether this coupling remains the same during different levels of nociception and pain. The main objective of the present study was to compare the amplitude of local field potentials (LFP) and cerebral blood flow (CBF) changes in the primary somatosensory cortex during nociceptive electrical stimulation of the contralateral or ipsilateral forepaw in isoflurane-anesthetized rats, while manipulating mean arterial pressure (MAP)...
December 18, 2016: Neuroscience
https://www.readbyqxmd.com/read/27976720/oscillatory-integration-windows-in-neurons
#15
Nitin Gupta, Swikriti Saran Singh, Mark Stopfer
Oscillatory synchrony among neurons occurs in many species and brain areas, and has been proposed to help neural circuits process information. One hypothesis states that oscillatory input creates cyclic integration windows: specific times in each oscillatory cycle when postsynaptic neurons become especially responsive to inputs. With paired local field potential (LFP) and intracellular recordings and controlled stimulus manipulations we directly test this idea in the locust olfactory system. We find that inputs arriving in Kenyon cells (KCs) sum most effectively in a preferred window of the oscillation cycle...
December 15, 2016: Nature Communications
https://www.readbyqxmd.com/read/27976678/distinct-effects-of-isoflurane-on-basal-bold-signals-in-tissue-vascular-microstructures-in-rats
#16
Tomokazu Tsurugizawa, Yukari Takahashi, Fusao Kato
Isoflurane is a well-known volatile anesthetic. However, it remains equivocal whether its effects on BOLD signal differ depending on the types of intracranial structures, such as capillaries and large blood vessels. We compared dose-dependent effect of isoflurane on the basal BOLD signals in distinct cerebral structures (tissue structure or large vessels) using high resolution T2*-images at 9.4 T MRI system in rat somatosensory cortex. The local field potential (LFP) in the somatosensory cortex and mean arterial pressure (MAP) were also investigated...
December 15, 2016: Scientific Reports
https://www.readbyqxmd.com/read/27935674/multiplexed-imaging-of-trace-residues-in-a-single-latent-fingerprint
#17
Yuyan Zhang, Wen Zhou, Yang Xue, Jie Yang, Dingbin Liu
The development of highly sensitive, selective, nondestructive, and multiplexed imaging modalities is essential for latent fingerprint (LFP) identification and fingerprint residues detection. Herein, we present a versatile strategy to identify LFPs and to probe the multiple trace residues in a single LFP simultaneously. With the purpose of achieving high sensitivity, we for the first time introduced a polydopamine (PDA)-triggered Au growth method to prepare superbright and multiplex surface-enhanced Raman scattering (SERS) tags, which were endowed with high selectivity by conjugating with specific antibodies...
December 9, 2016: Analytical Chemistry
https://www.readbyqxmd.com/read/27916831/long-term-task-and-dopamine-dependent-dynamics-of-subthalamic-local-field-potentials-in-parkinson-s-disease
#18
Sara J Hanrahan, Joshua J Nedrud, Bradley S Davidson, Sierra Farris, Monique Giroux, Aaron Haug, Mohammad H Mahoor, Anne K Silverman, Jun Jason Zhang, Adam Olding Hebb
Subthalamic nucleus (STN) local field potentials (LFP) are neural signals that have been shown to reveal motor and language behavior, as well as pathological parkinsonian states. We use a research-grade implantable neurostimulator (INS) with data collection capabilities to record STN-LFP outside the operating room to determine the reliability of the signals over time and assess their dynamics with respect to behavior and dopaminergic medication. Seven subjects were implanted with the recording augmented deep brain stimulation (DBS) system, and bilateral STN-LFP recordings were collected in the clinic over twelve months...
November 29, 2016: Brain Sciences
https://www.readbyqxmd.com/read/27916773/a-case-of-unresectable-combined-hepatocellular-cholangiocarcinoma-showing-favorable-response-to-lfp-therapy
#19
Sayuri Kato, Yasuto Takeuchi, Nozomu Wada, Yuuki Morimoto, Kenji Kuwaki, Hideki Ohnishi, Shinichiro Nakamura, Hidenori Shiraha, Akinobu Takaki, Hiroyuki Okada
A woman in her 50s was admitted to our hospital because of multiple tumors detected in her liver. She was diagnosed with combined hepatocellular cholangiocarcinoma using gadolinium-ethoxybenzyl-diethylenetriamine pentaacetic acid (Gd-EOB-DTPA)-enhanced magnetic resonance imaging (MRI) and biopsy of the liver tumors. We judged the tumors to be unresectable because they were found in both lobes of the liver, with a tumor thrombus being found in the main left portal vein. The pathological findings showed that the tumors exhibited characteristics of hepatocellular carcinoma...
2016: Nihon Shokakibyo Gakkai Zasshi, the Japanese Journal of Gastro-enterology
https://www.readbyqxmd.com/read/27913167/gamma-band-directional-interactions-between-basal-forebrain-and-visual-cortex-during-wake-and-sleep-states
#20
Jayakrishnan Nair, Arndt-Lukas Klaassen, Jordan Poirot, Alexei Vyssotski, Björn Rasch, Gregor Rainer
The basal forebrain (BF) is an important regulator of cortical excitability and responsivity to sensory stimuli, and plays a major role in wake-sleep regulation. While the impact of BF on cortical EEG or LFP signals has been extensively documented, surprisingly little is known about LFP activity within BF. Based on bilateral recordings from rats in their home cage, we describe endogenous LFP oscillations in the BF during quiet wakefulness, rapid eye movement (REM) and slow wave sleep (SWS) states. Using coherence and Granger causality methods, we characterize directional influences between BF and visual cortex (VC) during each of these states...
September 2016: Journal of Physiology, Paris
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