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high-frequency oscillations anesthesia

Sergey Burnos, Tommaso Fedele, Olivier Schmid, Niklaus Krayenbühl, Johannes Sarnthein
OBJECTIVE: The somatosensory evoked potential (SEP) elicited by median nerve stimulation consists of the N20 peak together with the concurrent high frequency oscillation (HFO, > 500 Hz). We describe the conditions for HFO detection in ECoG and scalp EEG in intraoperative recordings. METHODS: During neurosurgical interventions in six patients under propofol anesthesia, the SEP was recorded from subdural electrode strips (15 recordings) and from scalp electrodes (10/15 recordings)...
2016: NeuroImage: Clinical
Xing Liu, Jing Wang, Baoguo Wang, Ying Hua Wang, Qinglei Teng, Jiaqing Yan, Shuangyan Wang, You Wan
BACKGROUND: Transcutaneous acupoint electrical stimulation (TAES) as a needleless acupuncture has the same effect like traditional manual acupuncture. The combination of TAES and anesthesia has been proved valid in enhancing the anesthetic effects but its mechanisms are still not clear. METHODS: In this study, we investigated the effect of TAES on anesthesia with an electroencephalogram (EEG) oscillation analysis on surgery patients anesthetized with propofol, a widely-used anesthetic in clinical practice...
2016: BMC Complementary and Alternative Medicine
Andreas Steimer, Kaspar Schindler
Oscillations between high and low values of the membrane potential (UP and DOWN states respectively) are an ubiquitous feature of cortical neurons during slow wave sleep and anesthesia. Nevertheless, a surprisingly small number of quantitative studies have been conducted only that deal with this phenomenon's implications for computation. Here we present a novel theory that explains on a detailed mathematical level the computational benefits of UP states. The theory is based on random sampling by means of interspike intervals (ISIs) of the exponential integrate and fire (EIF) model neuron, such that each spike is considered a sample, whose analog value corresponds to the spike's preceding ISI...
2015: PloS One
Yia-Ping Liu, Yi-Hsien Lin, Yu-Chun Chen, Po-Lei Lee, Che-Se Tung
AIMS: Oscillations in arterial pressure and heart period in response to cold stress are poorly understood. We used a telemetric device with spectral and cross-spectral analyses to assess variabilities in the heart rate (HRV) and blood pressure (BPV) of conscious rats receiving a cooling stimulus (CS) (rapid immersion of palms and soles into 4°C water) at ambient thermoneutral conditions (TC), in a cold room (CC), and when under pentobarbital anesthesia (UA). MAIN METHODS: Power spectra of very low, low, and high frequencies (VLF: 0...
September 1, 2015: Life Sciences
Barbara Sinner, Oliver Friedrich, Regina Lindner, Anika Bundscherer, Bernhard M Graf
Ketamine and its stereoisomer S(+)-ketamine are widely used for sedation in pediatric anesthesia and intensive care medicine. Numerous experimental studies indicate that ketamine is potentially toxic to the developing brain. Here, we examined the long-term effects of NMDA receptor blockade on NMDA receptor subunit expression, alterations in neuronal Ca(2+)-oscillations and apoptosis. Hippocampal neurons, 15 days in culture, were exposed to either S(+)-ketamine or the NMDA receptor blocker MK801 for 24h. Cytosolic Ca(2+)-concentration was determined by fluorescence microscopy and the expression of the NMDA subunits NR1, NR2A and 2B was assessed by qRT-PCR, whereas Western blots and activated Caspase-3 served to measure the extent of apoptosis...
July 3, 2015: Toxicology
Ruggero G Bettinardi, Núria Tort-Colet, Marcel Ruiz-Mejias, Maria V Sanchez-Vives, Gustavo Deco
Intrinsic brain activity is characterized by the presence of highly structured networks of correlated fluctuations between different regions of the brain. Such networks encompass different functions, whose properties are known to be modulated by the ongoing global brain state and are altered in several neurobiological disorders. In the present study, we induced a deep state of anesthesia in rats by means of a ketamine/medetomidine peritoneal injection, and analyzed the time course of the correlation between the brain activity in different areas while anesthesia spontaneously decreased over time...
July 1, 2015: NeuroImage
Toshinobu Kuki, Kazuyuki Fujihara, Hideki Miwa, Nobuaki Tamamaki, Yuchio Yanagawa, Hajime Mushiake
Cortical interneurons are classified into several subtypes that contribute to cortical oscillatory activity. Parvalbumin (PV)-expressing cells, a type of inhibitory interneuron, are involved in the gamma oscillations of local field potentials (LFPs). Under ketamine-xylazine anesthesia or sleep, mammalian cortical circuits exhibit slow oscillations in which the active-up state and silent-down state alternate at ~1 Hz. The up state is composed of various high-frequency oscillations, including gamma oscillations...
2015: Frontiers in Neural Circuits
C Zheng, T Zhang
It is believed that phase synchronization facilitates neural communication and neural plasticity throughout the hippocampal-cortical network, and further supports cognition and memory. The pathway from the ventral hippocampus to the medial prefrontal cortex (mPFC) is thought to play a significant role in emotional memory processing. Therefore, the information transmission on the pathway was hypothesized to be disrupted in the depressive state, which could be related to its impaired synaptic plasticity. In this study, local field potentials (LFPs) from both ventral CA1 (vCA1) and mPFC were recorded in both normal and chronic unpredictable stress (CUS) model rats under urethane anesthesia...
April 30, 2015: Neuroscience
Clément Dubost, Adrien Bouglé, Calliope Hallynck, Matthieu Le Dorze, Philippe Roulleau, Catherine Baujard, Dan Benhamou
BACKGROUND AND AIMS: Cardiac output (CO) monitoring and goal-directed therapy during major abdominal surgery is currently used to decrease postoperative complications. However, few monitors are currently available for pediatric patients. Nicom(®) is a noninvasive CO monitoring technique based on the bioreactance principle (analysis of frequency variations of a delivered oscillating current traversing the thoracic cavity). Nicom(®) may be a useful monitor for pediatric patients. SUBJECTS AND METHODS: Pediatric patients undergoing major abdominal surgery under general anesthesia with cardiac monitoring by transesophageal Doppler (TED) were included...
January 2015: Indian Journal of Critical Care Medicine
Rowan Baker, Thomas C Gent, Qianzi Yang, Susan Parker, Alexei L Vyssotski, William Wisden, Stephen G Brickley, Nicholas P Franks
How general anesthetics cause loss of consciousness is unknown. Some evidence points toward effects on the neocortex causing "top-down" inhibition, whereas other findings suggest that these drugs act via subcortical mechanisms, possibly selectively stimulating networks promoting natural sleep. To determine whether some neuronal circuits are affected before others, we used Morlet wavelet analysis to obtain high temporal resolution in the time-varying power spectra of local field potentials recorded simultaneously in discrete brain regions at natural sleep onset and during anesthetic-induced loss of righting reflex in rats...
October 1, 2014: Journal of Neuroscience: the Official Journal of the Society for Neuroscience
Vesa Korhonen, Tuija Hiltunen, Teemu Myllylä, Xindi Wang, Jussi Kantola, Juha Nikkinen, Yu-Feng Zang, Pierre LeVan, Vesa Kiviniemi
Functional connectivity of the resting-state networks of the brain is thought to be mediated by very-low-frequency fluctuations (VLFFs <0.1 Hz) in neuronal activity. However, vasomotor waves and cardiorespiratory pulsations influence indirect measures of brain function, such as the functional magnetic resonance imaging blood-oxygen-level-dependent (BOLD) signal. How strongly physiological oscillations correlate with spontaneous BOLD signals is not known, partially due to differences in the data-sampling rates of different methods...
November 2014: Brain Connectivity
Leandro M Alonso, Alex Proekt, Theodore H Schwartz, Kane O Pryor, Guillermo A Cecchi, Marcelo O Magnasco
In this work we analyze electro-corticography (ECoG) recordings in human subjects during induction of anesthesia with propofol. We hypothesize that the decrease in responsiveness that defines the anesthetized state is concomitant with the stabilization of neuronal dynamics. To test this hypothesis, we performed a moving vector autoregressive analysis and quantified stability of neuronal dynamics using eigenmode decomposition of the autoregressive matrices, independently fitted to short sliding temporal windows...
2014: Frontiers in Neural Circuits
Darrell Haufler, Denis Pare
Previously, it was reported that various cortical and subcortical structures display high-frequency local field potential (LFP) oscillations in the 110- to 160-Hz range (HFOs), distinct from sharp-wave ripples. In the present study, we characterize HFOs in the extended amygdala. Rats were implanted with tetrode bundles in the bed nucleus of the stria terminalis (BNST), central amygdala (CeA), as well as adjacent regions (pallidum, caudate-putamen, and lateral septum). At all recorded sites, HFO power showed a systematic dependence on behavioral state: highest during quiet wakefulness, intermediate during paradoxical sleep, and lowest during active waking or slow-wave sleep...
July 1, 2014: Journal of Neurophysiology
Dong Hoon Lee, Keun Jung Ryu, Hae Ryong Song, Soo-Hong Han
BACKGROUND: The Intramedullary Skeletal Kinetic Distractor (ISKD) (Orthofix Inc, Lewisville, TX, USA) is an intramedullary device designed for more comfortable limb lengthening than that with external fixators; lengthening is achieved with this nail using rotational oscillation between two telescoping sections. However, the degree to which this device achieves this goal and its complication rate have not been fully documented. QUESTIONS/PURPOSES: We determined (1) the frequency with which distraction was not achieved at the desired rate, (2) whether pain differed between patients with normally and abnormally distracting nails, (3) risk factors for abnormal nails, and (4) other complications...
December 2014: Clinical Orthopaedics and related Research
Eran A Mukamel, Elvira Pirondini, Behtash Babadi, Kin Foon Kevin Wong, Eric T Pierce, P Grace Harrell, John L Walsh, Andres F Salazar-Gomez, Sydney S Cash, Emad N Eskandar, Veronica S Weiner, Emery N Brown, Patrick L Purdon
Rhythmic oscillations shape cortical dynamics during active behavior, sleep, and general anesthesia. Cross-frequency phase-amplitude coupling is a prominent feature of cortical oscillations, but its role in organizing conscious and unconscious brain states is poorly understood. Using high-density EEG and intracranial electrocorticography during gradual induction of propofol general anesthesia in humans, we discovered a rapid drug-induced transition between distinct states with opposite phase-amplitude coupling and different cortical source distributions...
January 15, 2014: Journal of Neuroscience: the Official Journal of the Society for Neuroscience
Romain Chery, Hirac Gurden, Claire Martin
Anesthetized preparations have been widely used to study odor-induced temporal dynamics in the olfactory bulb. Although numerous recent data of single-cell recording or imaging in the olfactory bulb have employed ketamine cocktails, their effects on networks activities are still poorly understood, and odor-induced oscillations of the local field potential have not been characterized under these anesthetics. Our study aimed at describing the impact of two ketamine cocktails on oscillations and comparing them to awake condition...
March 2014: Journal of Neurophysiology
I Ioan, B Demoulin, C Duvivier, A L Leblanc, C Bonabel, F Marchal, C Schweitzer, S Varechova
Aspirative capnography may be of help to diagnose early childhood asthma, but clinical usefulness in young children is limited by the relatively high respiratory rate. This study aimed to characterize the [Formula: see text] time course during airway constriction in 8 anesthetized rabbits, artificially ventilated at 30, 60 and 80breaths/min. Methacholine was inhaled to double the respiratory resistance measured at 8Hz by the forced oscillation technique. The capnogram shape changed in response to both methacholine and ventilatory frequency...
January 1, 2014: Respiratory Physiology & Neurobiology
Anastasia Greenberg, Clayton T Dickson
The neocortical slow oscillation (SO; ~1Hz) of non-REM sleep and anesthesia reflects synchronized network activity composed of alternating active and silent (ON/OFF) phases at the local network and cellular level. The SO itself shows self-organized spatiotemporal dynamics as it appears to originate at unique foci on each cycle and then propagates across the cortical surface. During sleep, this rhythm is relevant for neuroplastic processes mediating memory consolidation especially since its enhancement by slow, rhythmic electrical fields improves subsequent recall...
December 2013: NeuroImage
Charikleia S Vrettou, Spyros G Zakynthinos, Sotirios Malachias, Spyros D Mentzelopoulos
INTRODUCTION: In acute respiratory distress syndrome (ARDS), combined high-frequency oscillation (HFO) and tracheal gas insufflation (TGI) improves gas exchange compared with conventional mechanical ventilation (CMV). We evaluated the effect of HFO-TGI on PaO2/fractional inspired O2 (FiO2) and PaCO2, systemic hemodynamics, intracranial pressure (ICP), and cerebral perfusion pressure (CPP) in patients with traumatic brain injury (TBI) and concurrent severe ARDS. METHODS: We studied 13 TBI/ARDS patients requiring anesthesia, hyperosmolar therapy, and ventilation with moderate-to-high CMV-tidal volumes for ICP control...
2013: Critical Care: the Official Journal of the Critical Care Forum
Patrick L Purdon, Eric T Pierce, Eran A Mukamel, Michael J Prerau, John L Walsh, Kin Foon K Wong, Andres F Salazar-Gomez, Priscilla G Harrell, Aaron L Sampson, Aylin Cimenser, ShiNung Ching, Nancy J Kopell, Casie Tavares-Stoeckel, Kathleen Habeeb, Rebecca Merhar, Emery N Brown
Unconsciousness is a fundamental component of general anesthesia (GA), but anesthesiologists have no reliable ways to be certain that a patient is unconscious. To develop EEG signatures that track loss and recovery of consciousness under GA, we recorded high-density EEGs in humans during gradual induction of and emergence from unconsciousness with propofol. The subjects executed an auditory task at 4-s intervals consisting of interleaved verbal and click stimuli to identify loss and recovery of consciousness...
March 19, 2013: Proceedings of the National Academy of Sciences of the United States of America
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