scholarly journals Infraslow EEG activity modulates cortical excitability in postanoxic encephalopathy

2015 ◽  
Vol 113 (9) ◽  
pp. 3256-3267 ◽  
Author(s):  
Michel J. A. M. van Putten ◽  
Marleen C. Tjepkema-Cloostermans ◽  
Jeannette Hofmeijer
Keyword(s):  
Cortical Excitability ◽  
Rhythmic Activity ◽  
Burst Suppression ◽  
Eeg Activity ◽  
Scalp Eeg ◽  
Full Band ◽  
Eeg Power ◽  
Low Amplitude ◽  
The Relationship ◽  
Postanoxic Encephalopathy

Infraslow activity represents an important component of physiological and pathological brain function. We study infraslow activity (<0.1 Hz) in 41 patients with postanoxic coma after cardiac arrest, including the relationship between infraslow activity and EEG power in the 3–30 Hz range, using continuous full-band scalp EEG. In all patients, infraslow activity (0.015–0.06 Hz) was present, irrespective of neurological outcome or EEG activity in the conventional frequency bands. In two patients, low-amplitude (10–30 μV) infraslow activity was present while the EEG showed no rhythmic activity above 0.5 Hz. In 13/15 patients with a good outcome and 20/26 patients with a poor one, EEG power in the 3–30 Hz frequency range was correlated with the phase of infraslow activity, quantified by the modulation index. In 9/14 patients with burst-suppression with identical bursts, bursts appeared in clusters, phase-locked to the infraslow oscillations. This is substantiated by a simulation of burst-suppression in a minimal computational model. Infraslow activity is preserved in postanoxic encephalopathy and modulates cortical excitability. The strongest modulation is observed in patients with severe postanoxic encephalopathy and burst-suppression with identical bursts.

ID 92 – Infraslow EEG activity modulates cortical excitability in postanoxic encephalopathy

2016 ◽  
Vol 127 (3) ◽  
pp. e84
Author(s):  
M.J.A.M. van Putten ◽  
M.C. Tjepkema-Cloostermans ◽  
J. Hofmeijer
Keyword(s):  
Cortical Excitability ◽  
Eeg Activity ◽  
Postanoxic Encephalopathy

scholarly journals Zero-crossing patterns reveal subtle epileptiform discharges in the scalp EEG

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jan Pyrzowski ◽  
Jean- Eudes Le Douget ◽  
Amal Fouad ◽  
Mariusz Siemiński ◽  
Joanna Jędrzejczak ◽  
...  
Keyword(s):  
Normal Subjects ◽  
Intracranial Eeg ◽  
Zero Crossing ◽  
Temporal Precision ◽  
Scalp Eeg ◽  
Epileptiform Discharges ◽  
Interictal Epileptiform Discharges ◽  
Eeg Recordings ◽  
Patients With Epilepsy ◽  
Low Amplitude

AbstractClinical diagnosis of epilepsy depends heavily on the detection of interictal epileptiform discharges (IEDs) from scalp electroencephalographic (EEG) signals, which by purely visual means is far from straightforward. Here, we introduce a simple signal analysis procedure based on scalp EEG zero-crossing patterns which can extract the spatiotemporal structure of scalp voltage fluctuations. We analyzed simultaneous scalp and intracranial EEG recordings from patients with pharmacoresistant temporal lobe epilepsy. Our data show that a large proportion of intracranial IEDs manifest only as subtle, low-amplitude waveforms below scalp EEG background and could, therefore, not be detected visually. We found that scalp zero-crossing patterns allow detection of these intracranial IEDs on a single-trial level with millisecond temporal precision and including some mesial temporal discharges that do not propagate to the neocortex. Applied to an independent dataset, our method discriminated accurately between patients with epilepsy and normal subjects, confirming its practical applicability.

Effect of interleukin-1 beta on EEG power density during sleep depends on circadian phase

1996 ◽  
Vol 270 (4) ◽  
pp. R830-R837 ◽  
Author(s):  
M. Lancel ◽  
S. Mathias ◽  
J. Faulhaber ◽  
T. Schiffelholz
Keyword(s):  
Power Density ◽  
Interleukin 1 ◽  
Time Of Day ◽  
Controlled Study ◽  
Randomized Experiments ◽  
Eeg Activity ◽  
Circadian Phase ◽  
Activity Phase ◽  
Eeg Power ◽  
A Minor

The cytokine interleukin (IL)-1 is a key mediator of the somnogenic response to immune challenge. In this vehicle-controlled study we evaluated circadian interference with the sleep-promoting effects of IL-1 beta. In two randomized experiments, rats were injected intracerebroventricularly with 5 ng IL-1 beta either at the beginning of the rest phase or at the beginning of the activity phase. Recordings were made during the 24 h preceding the injections (baseline) and during the first 12 postinjection hours. To avoid masking effects of light, the rats were maintained under a skeleton photoperiod during recording. During both the rest and activity phase, IL-1 beta induced fever and initially promoted non-rapid eye movement sleep (REMS). The effect of IL-1 beta on the duration of non-REMS and electroencephalogram (EEG) power densities within non-REMS was related to circadian phase. During the rest phase, IL-1 beta resulted in a minor increase in non-REMS duration but a prominent enhancement in EEG activity in the delta (0.5-4 Hz) and most other frequency bands. During the activity phase, IL-1 beta evoked a larger increase in the duration of non-REMS but hardly affected EEG activity within this state. Thus the effects of IL-1 beta on non-REMS are strongly influenced by diurnal phase. The alterations in EEG power density are in contrast to those elicited by sleep deprivation, which are largely independent of time of day. It is concluded that IL-1 beta activates EEG regulatory mechanisms mediated by processes that depend on circadian phase.

Spatiotemporal characteristics of 5-HT and dopamine-induced rhythmic hindlimb activity in the in vitro neonatal rat

1996 ◽  
Vol 75 (4) ◽  
pp. 1472-1482 ◽  
Author(s):  
O. Kiehn ◽  
O. Kjaerulff
Keyword(s):  
Muscle Activity ◽  
Central Pattern Generators ◽  
Rhythmic Activity ◽  
Biceps Femoris ◽  
Ventral Root ◽  
Neonatal Rat ◽  
Cycle Duration ◽  
Spatiotemporal Characteristics ◽  
The Relationship

1. Rhythmic activity was induced with either serotonin (5-HT; 10-100 microM) or dopamine (0.1-1.0 mM), in the in vitro spinal cord preparation of neonatal rats, with one intact hindlimb attached. Patterns of activity were investigated with multiple EMG recordings and the spatiotemporal characteristics of 5-HT- and dopamine-induced activity compared. 2. Dopamine-induced rhythmic activity was slow (cycle duration: 2.2-70.1 s) and irregular, whereas rhythmic activity induced by 5-HT was fast (cycle duration: 1.3-5.1 s) and regular. 3. During 5-HT- and dopamine-induced rhythmic activity, the timing of muscular activity was similar for hip flexors and hip adductors, for semimembranosus (hip extensor), and for muscles controlling the ankle and the foot. 4. In contrast, notable differences in the phase in the pattern induced by 5-HT compared with that induced by dopamine were found in the biceps femoris, semitendinosus, and quadriceps muscles. Biceps femoris and semitendinosus (functional hip extensors and knee flexors) were always extensor-like during 5-HT-induced activity, whereas in dopamine, these muscles displayed flexor-like bursts and double bursts as well as extensor-like bursts. Lack of EMG activity in biceps femoris and semitendinosus was encountered also in dopamine. In rectus femoris, vastus lateralis, and vastus medialis (main function: knee extension), the activity was dominated by flexor-like bursts in 5-HT, whereas in dopamine the activity was shifted to a predominantly extensor-like pattern. 5. The relationship between flexor and extensor burst duration and cycle duration was more variable than described for locomotor activity in adult animals. 6. The relative timing of muscle activity was stable from P0 to P4. The most important difference between rats aged 0-1 days and rats aged 2-4 days was a delayed flexor-extensor transition in older animals. 7. The complex timing of hindlimb muscle activity was relatively unchanged after transecting all dorsal roots. 8. Finally, the relationship between flexor and extensor activity and ventral root discharges was determined. It was found that the L2 ventral root burst was in phase with simple flexors while the L5 burst coincide with the extensor phase. 9. We conclude, that 5-HT and dopamine can activate spinal central pattern generators (CPGs) that already at birth are able to produce distinct patterns of motor activity. Modulatory inputs thus seems to be able to reconfigure the CPGs to produce specific motor outputs.

Laminar excitability cycles in neocortex

1991 ◽  
Vol 65 (4) ◽  
pp. 891-898 ◽  
Author(s):  
D. S. Barth ◽  
S. Di
Keyword(s):  
Time Course ◽  
Microelectrode Array ◽  
Cortical Excitability ◽  
Initial Period ◽  
Current Source ◽  
Conditioning Stimulus ◽  
Principal Component ◽  
Evoked Response ◽  
Rat Somatosensory Cortex ◽  
The Relationship

1. Laminar field potentials produced by paired electrocortical stimuli were recorded with a linear microelectrode array inserted perpendicular to the surface of rat somatosensory cortex. Current source-density (CSD) distributions of the direct cortical response (DCR) were computed from the potential profiles. Principal component analysis (PCA) was used to estimate the time course of evoked transmembrane currents of putative pyramidal cell populations in the supragranular and infragranular layers. 2. Both supra- and infragranular cells displayed an initial period after the conditioning stimulus in which test stimuli produced subnormal evoked response amplitudes. This was followed in both layers by a long period of supernormal then subnormal responses and a second period of supernormal responses. 3. The main laminar difference encountered was a general shortening of all phases of the excitability cycle in the supragranular cells. 4. Excitability cycles in the supra- and infragranular layers closely followed the morphology of average evoked responses to the conditioning stimulus alone. These results and physiological support to the validity of lamina-specific evoked response waveforms derived from combined CSD and PCA analysis of extracellular potential measurements. 5. The relationship between evoked potential amplitude changes and cortical excitability is discussed.

Lipopolysaccharide increases EEG delta activity within non-REM sleep and disrupts sleep continuity in rats

1995 ◽  
Vol 268 (5) ◽  
pp. R1310-R1318 ◽  
Author(s):  
M. Lancel ◽  
J. Cronlein ◽  
P. Muller-Preuss ◽  
F. Holsboer
Keyword(s):  
Sleep Deprivation ◽  
Rem Sleep ◽  
Brain Temperature ◽  
Power Spectra ◽  
Eeg Activity ◽  
Eeg Power Spectra ◽  
Sleep Maintenance ◽  
Before And After ◽  
Delta Activity ◽  
Eeg Power

Activation of the immune system by microorganisms or specific microbial constituents promotes non-rapid-eye-movement (REM) sleep (non-REMS). In this study, we assessed the effects of lipopolysaccharide (LPS) on sleep duration, electroencephalogram (EEG) power spectra, and brain temperature (Tbr) in rats. Twenty-four hour recordings were made before and after intraperitoneal injection of vehicle or 30 or 100 micrograms/kg LPS at lights on. During the first 12 h after administration of both doses of LPS, Tbr was elevated, REMS duration was reduced, and non-REMS duration was unchanged, whereas the non-REMS episodes were shortened. EEG activity within non-REMS from 0.5 to 7 Hz was enhanced during hours 3-12. During the second 12-h period, the number of non-REMS and REMS episodes and the total time in both states were increased. EEG activity within non-REMS was mainly reduced in the entire frequency range (0.5-25.5 Hz). The effects of LPS did not differ between the doses. The effects of LPS on EEG power spectra are similar to those observed after sleep deprivation, i.e., a physiological intensification of non-REMS, indicating that both manipulations may activate common sleep EEG regulatory mechanisms. However, the disruption of non-REMS continuity following LPS administration at light onset contrasts the changes induced by sleep deprivation and may reflect an effect of a systemic inflammatory response on sleep maintenance.

Continuous Tonic Spike Activity in Spider Warm Cells in the Absence of Sensory Input

2006 ◽  
Vol 96 (3) ◽  
pp. 989-997 ◽  
Author(s):  
E. Gingl ◽  
H. Tichy
Keyword(s):  
Electrical Stimulation ◽  
Sensory Input ◽  
Discharge Rate ◽  
Rate Of Change ◽  
Intrinsic Properties ◽  
Response Curves ◽  
Temperature Changes ◽  
Different Temperatures ◽  
Low Amplitude ◽  
The Relationship

The warm cells of the spider tarsal organ respond very sensitively to low-amplitude changes in temperature and discharge continuously as the rate of change in temperature reaches zero. To test whether the continuous tonic discharge remains without sensory input, we blocked the warm cell's receptive region by Epoxy glue. The activity continued in this situation, but its dependence on temperature changes was strongly reduced. We interpret this to mean that the warm cells exhibit specific intrinsic properties that underlie the generation of the tonic discharge. Experiments with electrical stimulation confirmed the observation that the warm cells persist in activity without an external drive. In warm cells with blocked receptive region, the response curves describing the relationship between the tonic discharge and the level of depolarization is the same for different temperatures. In warm cells with intact receptive region, the curves are shifted upward with rising temperature, as if the injected current is simply added to the receptor current. This indicates a modulating effect of the receptor current on the tonic discharge. Stimulation causes a change in the tonic discharge rate and thereby enables individual warm cells to signal the direction in addition to the magnitude of temperature changes.

scholarly journals Influence of Binasal and Uninasal Inhalations of Essential Oil of Abies koreana Twigs on Electroencephalographic Activity of Human

2016 ◽  
Vol 2016 ◽  
pp. 1-11 ◽  
Author(s):  
Min Seo ◽  
Kandhasamy Sowndhararajan ◽  
Songmun Kim
Keyword(s):  
Essential Oil ◽  
Steam Distillation ◽  
Bornyl Acetate ◽  
Eeg Activity ◽  
Eeg Power Spectrum ◽  
Abies Koreana ◽  
Left And Right ◽  
Eeg Power ◽  
The Right ◽  
Electroencephalographic Activity

Objectives. The present work investigates the effect of essential oil from the twigs of Abies koreana on electroencephalographic (EEG) activity of human brain in order to understand the influence of binasal and uninasal inhalations. Methods. To accomplish this study, the essential oil from the twigs of A. koreana (AEO) was isolated by steam distillation and the EEG readings were recorded using QEEG-8 system from 8 grounding electrodes according to the International 10-20 System. Results. D-Limonene (25.29%), bornyl acetate (19.31%), camphene (12.48%), α-pinene (11.88%), β-pinene (6.45%), and eudesm-7(11)-en-ol (5.38%) were the major components in the essential oil. In the EEG study, the absolute alpha (left frontal and right parietal) and absolute fast alpha (right parietal) values significantly increased during the binasal inhalation of AEO. In the uninasal inhalation, absolute beta and theta values decreased significantly, especially in the right frontal and left and right parietal regions. The results revealed that the AEO produced different EEG power spectrum changes according to the nostril difference. Conclusion. The changes in EEG values due to the inhalation of AEO may contribute to the enhancement of relaxation (binasal inhalation) and alertness/attention (right uninasal inhalation) states of brain which could be used in aromatherapy treatments.

EEG power spectral density under Propofol and its association with burst suppression, a marker of cerebral fragility

2019 ◽  
Vol 130 (8) ◽  
pp. 1311-1319 ◽  
Author(s):  
Cyril Touchard ◽  
Jérôme Cartailler ◽  
Charlotte Levé ◽  
Pierre Parutto ◽  
Cédric Buxin ◽  
...  
Keyword(s):  
Spectral Density ◽  
Power Spectral Density ◽  
Burst Suppression ◽  
Power Spectral ◽  
Eeg Power
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