Abstract #37: Closed-Loop tACS Targeting Slow-Wave Oscillations During Sleep Enhances Consolidation of Generalized Information

AbstractSlow-wave sleep cortical brain activity, conformed by slow-oscillations and sleep spindles, plays a key role in memory consolidation. The increase of the power of the slow-wave events, obtained by auditory sensory stimulation, positively correlates to memory consolidation performance. However, little is known about the experimental protocol maximizing this effect, which could be induced by the power of slow-oscillation, the number of sleep spindles, or the timing of both events’ co-occurrence. Using a mean-field model of thalamocortical activity, we studied the effect of several stimulation protocols, varying the pulse shape, duration, amplitude, and frequency, as well as a target-phase using a closed-loop approach. We evaluated the effect of these parameters on slow-oscillations (SO) and sleep-spindles (SP), considering: (i) the power at the frequency bands of interest, (ii) the number of SO and SP, (iii) co-occurrences between SO and SP, and (iv) synchronization of SP with the up-peak of the SO. The first three targets are maximized using a decreasing ramp pulse with a pulse duration of 50 ms. Also, we observed a reduction in the number of SO when increasing the stimulus energy by rising its amplitude. To assess the target-phase parameter, we applied closed-loop stimulation at 0º, 45º, and 90º of the phase of the narrow-band filtered ongoing activity, at 0.85 Hz as central frequency. The 0º stimulation produces better results in the power and number of SO and SP than the rhythmic or aleatory stimulation. On the other hand, stimulating at 45º or 90º change the timing distribution of spindles centers but with fewer co-occurrences than rhythmic and 0º phase. Finally, we propose the application of closed-loop stimulation at the rising zero-cross point using pulses with a decreasing ramp shape and 50 ms of duration for future experimental work.Author summaryDuring the non-REM (NREM) phase of sleep, events that are known as slow oscillations (SO) and spindles (SP) can be detected by EEG. These events have been associated with the consolidation of declarative memories and learning. Thus, there is an ongoing interest in promoting them during sleep by non-invasive manipulations such as sensory stimulation. In this paper, we used a computational model of brain activity that generates SO and SP, to investigate which type of sensory stimulus –shape, amplitude, duration, periodicity– would be optimal for increasing the events’ frequency and their co-occurrence. We found that a decreasing ramp of 50 ms duration is the most effective. The effectiveness increases when the stimulus pulse is delivered in a closed-loop configuration triggering the pulse at a target phase of the ongoing SO activity. A desirable secondary effect is to promote SPs at the rising phase of the SO oscillation.

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Examining the optimal timing for closed-loop auditory stimulation of slow-wave sleep in young and older adults

SLEEP ◽

10.1093/sleep/zsz315 ◽

2019 ◽

Vol 43 (6) ◽

Cited By ~ 5

Author(s):

Miguel Navarrete ◽

Jules Schneider ◽

Hong-Viet V Ngo ◽

Mario Valderrama ◽

Alexander J Casson ◽

...

Keyword(s):

Slow Wave ◽

Closed Loop ◽

Slow Wave Sleep ◽

Auditory Stimulation ◽

Optimal Time ◽

Optimal Timing ◽

Experimental Conditions ◽

Young Subjects ◽

The Impact ◽

Specific Phase

Abstract Study Objectives Closed-loop auditory stimulation (CLAS) is a method for enhancing slow oscillations (SOs) through the presentation of auditory clicks during sleep. CLAS boosts SOs amplitude and sleep spindle power, but the optimal timing for click delivery remains unclear. Here, we determine the optimal time to present auditory clicks to maximize the enhancement of SO amplitude and spindle likelihood. Methods We examined the main factors predicting SO amplitude and sleep spindles in a dataset of 21 young and 17 older subjects. The participants received CLAS during slow-wave-sleep in two experimental conditions: sham and auditory stimulation. Post-stimulus SOs and spindles were evaluated according to the click phase on the SOs and compared between and within conditions. Results We revealed that auditory clicks applied anywhere on the positive portion of the SO increased SO amplitudes and spindle likelihood, although the interval of opportunity was shorter in the older group. For both groups, analyses showed that the optimal timing for click delivery is close to the SO peak phase. Click phase on the SO wave was the main factor determining the impact of auditory stimulation on spindle likelihood for young subjects, whereas for older participants, the temporal lag since the last spindle was a better predictor of spindle likelihood. Conclusions Our data suggest that CLAS can more effectively boost SOs during specific phase windows, and these differ between young and older participants. It is possible that this is due to the fluctuation of sensory inputs modulated by the thalamocortical networks during the SO.

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Myogenic mechanism for peristalsis in the cat esophagus

AJP Gastrointestinal and Liver Physiology ◽

10.1152/ajpgi.1999.277.2.g306 ◽

1999 ◽

Vol 277 (2) ◽

pp. G306-G313 ◽

Cited By ~ 6

Author(s):

Harold G. Preiksaitis ◽

Nicholas E. Diamant

Keyword(s):

Muscle Contraction ◽

Slow Wave ◽

Circular Muscle ◽

Smooth Muscle Contraction ◽

Slow Waves ◽

Mechanical Activity ◽

Control Mechanisms ◽

Slow Wave Oscillations

A myogenic control system (MCS) is a fundamental determinant of peristalsis in the stomach, small bowel, and colon. In the esophagus, attention has focused on neuronal control, the potential for a MCS receiving less attention. The myogenic properties of the cat esophagus were studied in vitro with and without nerves blocked by 1 μM TTX. Muscle contraction was recorded, while electrical activity was monitored by suction electrodes. Spontaneous, nonperistaltic, electrical, and mechanical activity was seen in the longitudinal muscle and persisted after TTX. Spontaneous circular muscle activity was minimal, and peristalsis was not observed without pharmacological activation. Direct electrical stimulation (ES) in the presence of bethanechol or tetraethylammonium chloride (TEA) produced slow-wave oscillations and spike potentials accompanying smooth muscle contraction that progressed along the esophagus. Increased concentrations of either drug in the presence of TTX produced slow waves and spike discharges, accompanied by peristalsis in 5 of 8 TEA- and 2 of 11 bethanechol-stimulated preparations without ES. Depolarization of the muscle by increasing K+ concentration also produced slow waves but no peristalsis. We conclude that the MCS in the esophagus requires specific activation and is manifest by slow-wave oscillations of the membrane potential, which appear to be necessary, but are not sufficient for myogenic peristalsis. In vivo, additional control mechanisms are likely supplied by nerves.

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Network-Specific Synchronization of Electrical Slow-Wave Oscillations Regulates Sleep Drive in Drosophila

Current Biology ◽

10.1016/j.cub.2019.08.070 ◽

2019 ◽

Vol 29 (21) ◽

pp. 3611-3621.e3 ◽

Cited By ~ 16

Author(s):

Davide Raccuglia ◽

Sheng Huang ◽

Anatoli Ender ◽

M.-Marcel Heim ◽

Desiree Laber ◽

...

Keyword(s):

Slow Wave ◽

Sleep Drive ◽

Slow Wave Oscillations

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Interactions Between Membrane Conductances Underlying Thalamocortical Slow-Wave Oscillations

Physiological Reviews ◽

10.1152/physrev.00012.2003 ◽

2003 ◽

Vol 83 (4) ◽

pp. 1401-1453 ◽

Cited By ~ 151

Author(s):

A. DESTEXHE ◽

T. J. SEJNOWSKI

Keyword(s):

Experimental Data ◽

Single Cell ◽

Slow Wave ◽

Large Scale ◽

Slow Wave Sleep ◽

Large Body ◽

Electrophysiological Properties ◽

Membrane Conductances ◽

Synaptic Receptors ◽

Slow Wave Oscillations

Destexhe, A., and T. J. Sejnowski. Interactions Between Membrane Conductances Underlying Thalamocortical Slow-Wave Oscillations. Physiol Rev 83: 1401-1453, 2003; 10.1152/physrev.00012.2003.—Neurons of the central nervous system display a broad spectrum of intrinsic electrophysiological properties that are absent in the traditional “integrate-and-fire” model. A network of neurons with these properties interacting through synaptic receptors with many time scales can produce complex patterns of activity that cannot be intuitively predicted. Computational methods, tightly linked to experimental data, provide insights into the dynamics of neural networks. We review this approach for the case of bursting neurons of the thalamus, with a focus on thalamic and thalamocortical slow-wave oscillations. At the single-cell level, intrinsic bursting or oscillations can be explained by interactions between calcium- and voltage-dependent channels. At the network level, the genesis of oscillations, their initiation, propagation, termination, and large-scale synchrony can be explained by interactions between neurons with a variety of intrinsic cellular properties through different types of synaptic receptors. These interactions can be altered by neuromodulators, which can dramatically shift the large-scale behavior of the network, and can also be disrupted in many ways, resulting in pathological patterns of activity, such as seizures. We suggest a coherent framework that accounts for a large body of experimental data at the ion-channel, single-cell, and network levels. This framework suggests physiological roles for the highly synchronized oscillations of slow-wave sleep.

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Analysis of Slow Wave Oscillations in Cerebral Haemodynamics and Metabolism Following Subarachnoid Haemorrhage

Advances in Experimental Medicine and Biology - Oxygen Transport to Tissue XXXVI ◽

10.1007/978-1-4939-0620-8_26 ◽

2014 ◽

pp. 195-201 ◽

Cited By ~ 3

Author(s):

David Highton ◽

Arnab Ghosh ◽

Ilias Tachtsidis ◽

Clare Elwell ◽

Martin Smith

Keyword(s):

Subarachnoid Haemorrhage ◽

Slow Wave ◽

Cerebral Haemodynamics ◽

Slow Wave Oscillations

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Slow wave oscillations in Schizophrenia First-Degree Relatives: A confirmatory analysis and feasibility study on slow wave traveling

Schizophrenia Research ◽

10.1016/j.schres.2020.03.025 ◽

2020 ◽

Vol 221 ◽

pp. 37-43 ◽

Cited By ~ 1

Author(s):

Anna Castelnovo ◽

Matteo Zago ◽

Cecilia Casetta ◽

Caroline Zangani ◽

Francesco Donati ◽

...

Keyword(s):

Feasibility Study ◽

Slow Wave ◽

First Degree Relatives ◽

Confirmatory Analysis ◽

Slow Wave Oscillations

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On the issue of the electroencephalographic phenomenon «burst-suppression»: variants of outcomes and possible neurophysiological mechanisms

Medical alphabet ◽

10.33667/2078-5631-2021-5-42-49 ◽

2021 ◽

pp. 42-49

Author(s):

A. Yu. Mikhailov ◽

I. Yu. Berezina ◽

L. I. Sumsky ◽

Yu. L. Arzumanov

Keyword(s):

Spectral Analysis ◽

Electrical Activity ◽

Slow Wave ◽

Burst Suppression ◽

Temporal Lobes ◽

Equivalent Dipole ◽

Neurophysiological Mechanisms ◽

The Brain ◽

Dipole Sources ◽

Slow Wave Oscillations

Objective: to evaluate the indicators of electrical activity of the brain using frequency- spectral analysis and data of three- dimensional localization of sources of pathological activity for an approach to the analysis of possible neurophysiological mechanisms of the brain of patients whose EEG recorded the phenomenon of ‘burst- suppression’.Material and methods: 45 electroencephalograms recorded in 22 patients (average age 51.05; 11 women, 11 men) were analyzed. In 12 patients, the EEG study was performed in dynamics from 1 to 8 times. At the time of the first registration, the ‘burst- suppression’phenomenon was recorded in the EEG of all patients. The level of wakefulness of all patients, with the exception of patients who were under anesthesia, was 3 points on the Glasgow coma scale.EEG recording was performed on electroencephalographs ‘Encephalan- EEGR-19/26’, ‘Mitsar- EEG-10/70–201’, ‘Mitsar- EEG-SmartBCI’, ‘Neuron- Spectrum-5’and ‘Neuron- Spectrum-65’in accordance with the International scheme of arrangement of electrodes 10–20 %. A frequency- spectral analysis of the power of the ‘burst’and ‘suppression’periods was carried out — the fast Fourier transform method was used. The program ‘BrainLoc 6.1’(Russia) was used for localization of equivalent dipole sources of pathological electrical activity of the ‘burst’period.Results: during the first EEG recording, the ‘burst- suppression’phenomenon was recorded in all patients. In seven patients, the ‘burst’period in the ‘burstsuppression’phenomenon was visually represented by slow-wave oscillations, in 15 patients, the ‘burst’periods resembled epileptiform discharges. In frequency- spectral analysis EEG in all patients in the ‘burst’period, the dominance of the power of slow-wave oscillations (mainly in the delta range) was noted. According to the program ‘BrainLoc 6.1’, equivalent dipole sources of pathological activity of the ‘burst’period were recorded at the level of the thalamus, in the medio- basal parts of the frontal and temporal lobes on both sides. A favorable outcome of the ‘burst- suppression’phenomenon was observed in only five patients of 22, all other patients had an unfavorable outcome.Conclusion: a favorable outcome of the ‘burst- suppression’phenomenon was observed only in patients under sevorane anesthesia and in some patients after acute poisoning with drugs that affect the central nervous system, while patients after brain anoxia had an unfavorable outcome. In prognostic terms, our data are comparable to the literature data. The changes revealed during the frequency-spectral analysis of the EEG in the form of the dominance of the power of slow-wave oscillations (mainly in the delta range), as well as the localization of the supposed generators of electrical activity in the ‘burst’ period at the level of the thalamus, in the mediobasal parts of the frontal and temporal lobes (according to the ‘BrainLoc 6.1’program), may to some extent be consistent with the data of experimental works and mathematical models of the ‘burst–suppression’phenomenon If the ‘burst- suppression’ phenomenon is detected during EEG registration, it is advisableto conduct a dynamic EEG study or EEG monitoring.

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Neuronal plasticity during sleep slow wave oscillations

BMC Neuroscience ◽

10.1186/1471-2202-15-s1-p216 ◽

2014 ◽

Vol 15 (Suppl 1) ◽

pp. P216

Author(s):

Yina Wei ◽

Giri P Krishnan ◽

Maxim Bazhenov

Keyword(s):

Slow Wave ◽

Neuronal Plasticity ◽

Slow Wave Oscillations

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