Intrinsic reinstatement of induced oscillatory context

AbstractDeclarative memory retrieval is thought to rely on the reinstatement, at retrieval, of contextual cues present during encoding, as evidenced in the context and state-dependent literature. Specifically, previous work has shown that reinstating the oscillatory activity present during encoding, at retrieval, is particularly supportive of memory recall. Our study builds on previous findings suggesting that the oscillatory activity present at encoding may be automatically reinstated during retrieval. To explore the roles of consolidation, prefrontal involvement, and frequency specific activity in this process of oscillatory reinstatement, 115 healthy young adults were randomly assigned to one of five conditions. In each condition, transcranial alternating current stimulation (tACS) was administered at either one of two frequencies (60Hz or 6Hz), over the left dorsolateral prefrontal cortex (left-DLPFC, Experimental) or the right primary motor cortex (right-PMC, Control), during learning of written words. This was followed by a retention interval of either 90 minutes or 1 week and a testing phase, during which EEG activity was recorded. Our results showed significant (and frequency specific) oscillatory reinstatement, after stimulation of the left-DLPFC, in the 1-week retention condition. Oscillatory reinstatement effects were non-significant after stimulation of the right-PMC, or in the 90 minutes retention interval condition. Our results highlight that the oscillatory activity induced during encoding is consolidated as context alongside the information and is reinstated intrinsically during retrieval. The implications of our findings for models of human memory, future avenues of research and clinical applications are discussed.

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High-definition transcranial direct-current stimulation of the right M1 further facilitates left M1 excitability during crossed facilitation

Journal of Neurophysiology ◽

10.1152/jn.00861.2017 ◽

2018 ◽

Vol 119 (4) ◽

pp. 1266-1272 ◽

Cited By ~ 12

Author(s):

Vincent Cabibel ◽

Makii Muthalib ◽

Wei-Peng Teo ◽

Stephane Perrey

Keyword(s):

Direct Current ◽

Transcranial Direct Current Stimulation ◽

Primary Motor Cortex ◽

Motor Evoked Potentials ◽

Single Pulse ◽

High Definition ◽

Maximum Voluntary Isometric Contraction ◽

Direct Current Stimulation ◽

The Right ◽

Stimulation Of

The crossed-facilitation (CF) effect refers to when motor-evoked potentials (MEPs) evoked in the relaxed muscles of one arm are facilitated by contraction of the opposite arm. The aim of this study was to determine whether high-definition transcranial direct-current stimulation (HD-tDCS) applied to the right primary motor cortex (M1) controlling the left contracting arm [50% maximum voluntary isometric contraction (MVIC)] would further facilitate CF toward the relaxed right arm. Seventeen healthy right-handed subjects participated in an anodal and cathodal or sham HD-tDCS session of the right M1 (2 mA for 20 min) separated by at least 48 h. Single-pulse transcranial magnetic stimulation (TMS) was used to elicit MEPs and cortical silent periods (CSPs) from the left M1 at baseline and 10 min into and after right M1 HD-tDCS. At baseline, compared with resting, CF (i.e., right arm resting, left arm 50% MVIC) increased left M1 MEP amplitudes (+97%) and decreased CSPs (−11%). The main novel finding was that right M1 HD-tDCS further increased left M1 excitability (+28.3%) and inhibition (+21%) from baseline levels during CF of the left M1, with no difference between anodal and cathodal HD-tDCS sessions. No modulation of CSP or MEP was observed during sham HD-tDCS sessions. Our findings suggest that CF of the left M1 combined with right M1 anodal or cathodal HD-tDCS further facilitated interhemispheric interactions during CF from the right M1 (contracting left arm) toward the left M1 (relaxed right arm), with effects on both excitatory and inhibitory processing. NEW & NOTEWORTHY This study shows modulation of the nonstimulated left M1 by right M1 HD-tDCS combined with crossed facilitation, which was probably achieved through modulation of interhemispheric interactions.

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Muscle and Timing-specific Functional Connectivity between the Dorsolateral Prefrontal Cortex and the Primary Motor Cortex

Journal of Cognitive Neuroscience ◽

10.1162/jocn_a_00338 ◽

2013 ◽

Vol 25 (4) ◽

pp. 558-570 ◽

Cited By ~ 34

Author(s):

Alkomiet Hasan ◽

Joseph M. Galea ◽

Elias P. Casula ◽

Peter Falkai ◽

Sven Bestmann ◽

...

Keyword(s):

Functional Connectivity ◽

Motor Cortex ◽

Animal Studies ◽

Primary Motor Cortex ◽

Adjacent Area ◽

Left Dlpfc ◽

Dorsolateral Prefrontal ◽

The Difference ◽

Selection Tasks ◽

The Right

The pFC has a crucial role in cognitive control, executive function, and sensory processing. Functional imaging, neurophysiological, and animal studies provide evidence for a functional connectivity between the dorsolateral pFC (DLPFC) and the primary motor cortex (M1) during free choice but not instructed choice selection tasks. In this study, twin coil, neuronavigated TMS was used to examine the precise timing of the functional interaction between human left DLPFC and ipsilateral M1 during the execution of a free/specified choice selection task involving the digits of the right hand. In a thumb muscle that was not involved in the task, a conditioning pulse to the left DLPFC enhanced the excitability of the ipsilateral M1 during free selection more than specified selection 100 msec after presentation of the cue; the opposite effect was seen at 75 msec. However, the difference between free and externally specified conditions disappeared when a task-specific muscle was investigated. In this case, the influence from DLPFC was dominated by task involvement rather than mode of selection, suggesting that other processes related to movement execution were also operating. Finally, we show that the effects were spatially specific because they were absent when an adjacent area of DLPFC was stimulated. These results reveal temporally and spatially selective interactions between BA 46 and M1 that are both task and muscle specific.

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Phosphene perceptions and safety of chronic visual cortex stimulation in a blind subject

Journal of Neurosurgery ◽

10.3171/2019.3.jns182774 ◽

2020 ◽

Vol 132 (6) ◽

pp. 2000-2007 ◽

Cited By ~ 3

Author(s):

Soroush Niketeghad ◽

Abirami Muralidharan ◽

Uday Patel ◽

Jessy D. Dorn ◽

Laura Bonelli ◽

...

Keyword(s):

Visual Cortex ◽

Adverse Events ◽

Clinical Intervention ◽

Occipital Cortex ◽

Neuronal Population ◽

Serious Adverse Events ◽

Stimulation Parameters ◽

The Right ◽

Visual Cortical ◽

Stimulation Of

Stimulation of primary visual cortices has the potential to restore some degree of vision to blind individuals. Developing safe and reliable visual cortical prostheses requires assessment of the long-term stability, feasibility, and safety of generating stimulation-evoked perceptions.A NeuroPace responsive neurostimulation system was implanted in a blind individual with an 8-year history of bare light perception, and stimulation-evoked phosphenes were evaluated over 19 months (41 test sessions). Electrical stimulation was delivered via two four-contact subdural electrode strips implanted over the right medial occipital cortex. Current and charge thresholds for eliciting visual perception (phosphenes) were measured, as were the shape, size, location, and intensity of the phosphenes. Adverse events were also assessed.Stimulation of all contacts resulted in phosphene perception. Phosphenes appeared completely or partially in the left hemifield. Stimulation of the electrodes below the calcarine sulcus elicited phosphenes in the superior hemifield and vice versa. Changing the stimulation parameters of frequency, pulse width, and burst duration affected current thresholds for eliciting phosphenes, and increasing the amplitude or frequency of stimulation resulted in brighter perceptions. While stimulation thresholds decreased between an average of 5% and 12% after 19 months, spatial mapping of phosphenes remained consistent over time. Although no serious adverse events were observed, the subject experienced mild headaches and dizziness in three instances, symptoms that did not persist for more than a few hours and for which no clinical intervention was required.Using an off-the-shelf neurostimulator, the authors were able to reliably generate phosphenes in different areas of the visual field over 19 months with no serious adverse events, providing preliminary proof of feasibility and safety to proceed with visual epicortical prosthetic clinical trials. Moreover, they systematically explored the relationship between stimulation parameters and phosphene thresholds and discovered the direct relation of perception thresholds based on primary visual cortex (V1) neuronal population excitation thresholds.

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Faculty Opinions recommendation of Increased facilitation of the primary motor cortex following 1 Hz repetitive transcranial magnetic stimulation of the contralateral cerebellum in normal humans.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.1025006.294756 ◽

2005 ◽

Author(s):

Mark Hallett

Keyword(s):

Transcranial Magnetic Stimulation ◽

Motor Cortex ◽

Magnetic Stimulation ◽

Primary Motor Cortex ◽

Repetitive Transcranial Magnetic Stimulation ◽

Normal Humans ◽

Stimulation Of

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INFLUENCE OF RIGHT VENTRICULAR LEAD IMPLANTATION SITE CHOICE ON PACING EFFICIENCY

International Medical Journal ◽

10.37436/2308-5274-2019-4-3 ◽

2020 ◽

pp. 13-17

Author(s):

Dmitrii Aleksandrovich Lopyn ◽

Stanislav Valerevich Rybchynskyi ◽

Dmitrii Evgenevich Volkov

Keyword(s):

Heart Failure ◽

Right Ventricular ◽

Longitudinal Strain ◽

Treatment Options ◽

Global Longitudinal Strain ◽

Optimal Method ◽

Cardiac Stimulation ◽

Ventricular Lead ◽

The Right ◽

Stimulation Of

Currently the electrophysiological treatment options have been considered to be the most effective for many patients with arrhythmogenic cardiomyopathies, as well as in those with arrhythmias on the background of heart failure. Currently, the dependence of efficiency of the pacemakers on the location of the electrodes has been proven. In order to study the effect of a myocardial dysynchrony on the effectiveness of pacing depending on the location of the right ventricular electrode, an investigation has been performed. This study comprised the patients with a complete atrioventricular block, preserved ejection fraction of the left ventricle (more than 50 %), with no history of myocardial infarction, who were implanted with the two−chamber pacemaker. It has been established that the best results were achieved with a stimulation of the middle and lower septal zone of the right ventricle, the worst ones were obtained with a stimulation of its apex. It has been found that the dynamics of the magnitude of segmental strains and a global longitudinal strain coincided with the dynamics of other parameters of the pacemaker effectiveness, which indicated the pathogenetic value of myocardial dysynchrony in the progression of heart failure after implantation of the pacemaker. Therefore it could be concluded that the studying of myocardial mobility by determining a longitudinal strain for assessing the functional state of the myocardium and the effectiveness of pacing is highly advisable. It is emphasized that the use of the latest strains−dependent techniques for cardiac performance evaluation in the patients with bradyarrhythmia have a great potential to predict the development of chronic heart failure and to choose the optimal method of physiological stimulation of the heart. Key words: right ventricular lead, cardiac stimulation, myocardial dyssynchrony.

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СТИМУЛИРОВАНИЕ ПРАВОПОСЛУШНОГО ПОВЕДЕНИЯ ОСУЖДЕННЫХ В МЕСТАХ ЛИШЕНИЯ СВОБОДЫ В СОВЕТСКОМ И СОВРЕМЕННОМ РОССИЙСКОМ ЗАКОНОДАТЕЛЬСТВЕ

Vestnik Samarskogo iuridicheskogo instituta ◽

10.37523/sui.2019.36.5.008 ◽

2020 ◽

Author(s):

Stanislav Kuzmin ◽

Irina Polyanskaya

Keyword(s):

Criminal Punishment ◽

Personal Time ◽

Labor Camps ◽

Archival Documents ◽

Legal Position ◽

Executive System ◽

The Right ◽

Stimulation Of

Статья подготовлена на основе использования нормативных правовых актов и архивных документов различных исправительно-трудовых лагерей, указанных в сносках, что позволяет судить о территориальных рамках источников. Исследуется генезис становления и развития практики стимулирования правопослушного поведения осужденных посредством норм, не изменяющих их правовое положение в период отбывания уголовного наказания в виде лишения свободы на различных этапах функционирования исправительно-трудовой (уголовно-исполнительной) системы. На основе изученных документов можно сделать вывод, что в основу дифференциации поощрительных норм, распространявшихся на осужденных, положены следующие критерии: 1) поощрения, не изменяющие условия отбывания уголовного наказания в виде лишения свободы; 2) поощрения, изменяющие условия содержания осужденных. Из ранее применявшихся мер поощрений в современном уголовно-исполнительном законодательстве используются следующие: объявление благодарности с занесением в личное дело, материальное поощрение, право на дополнительную посылку, передачу и др. Среди других мер поощрения можно выделить увеличение времени ежедневной прогулки до двух часов для осужденных, содержащихся в строгих условиях отбывания наказания в колониях и тюрьмах. Также законодатель предусмотрел возможность проводить праздничные и выходные дни за пределами учреждения для осужденных, содержащихся в колониях-поселениях.The article is prepared on the basis of the use of normative legal acts and archival documents of various correctional labor camps mentioned in the footnotes, which allows to judge the territorial scope of the sources. The Genesis of formation and development of practice of stimulation of law-abiding behavior of condemned by means of the norms which are not changing their legal position during serving of criminal punishment in the form of imprisonment at various stages of functioning of correctional labor (criminal Executive) system is investigated. On the basis of the studied documents, it can be concluded that the basis for the differentiation of incentive norms that apply to convicts are the following criteria: 1) incentives that do not change the conditions of serving a criminal sentence in the form of imprisonment; 2) incentives that change the conditions of detention of convicts. Of the previously applied measures of incentives in the modern penal legislation the following are used: the announcement of gratitude with entering in personal time, material encouragement, the right to an additional parcel, transfer, etc. Among other measures of encouragement it is possible to allocate increase in time of daily walk to two hours for condemned detainees in strict conditions of serving of punishment in colonies and prisons. Also, the legislator provided the opportunity to spend holidays and weekends outside the institution for convicts held in colonies-settlements.

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Reduced Interhemispheric Coherence in Cerebellar Kainic Acid-Induced Lateralized Dystonia

Frontiers in Neurology ◽

10.3389/fneur.2020.580540 ◽

2020 ◽

Vol 11 ◽

Author(s):

Elena Laura Georgescu Margarint ◽

Ioana Antoaneta Georgescu ◽

Carmen Denise Mihaela Zahiu ◽

Stefan-Alexandru Tirlea ◽

Alexandru Rǎzvan Şteopoaie ◽

...

Keyword(s):

Motor Cortex ◽

Kainic Acid ◽

Primary Motor Cortex ◽

Low Frequency ◽

Muscular Activity ◽

Cerebellar Hemisphere ◽

Interhemispheric Coherence ◽

General Locomotor Activity ◽

Complex Circuits ◽

The Right

The execution of voluntary muscular activity is controlled by the primary motor cortex, together with the cerebellum and basal ganglia. The synchronization of neural activity in the intracortical network is crucial for the regulation of movements. In certain motor diseases, such as dystonia, this synchrony can be altered in any node of the cerebello-cortical network. Questions remain about how the cerebellum influences the motor cortex and interhemispheric communication. This research aims to study the interhemispheric cortical communication between the motor cortices during dystonia, a neurological movement syndrome consisting of sustained or repetitive involuntary muscle contractions. We pharmacologically induced lateralized dystonia to adult male albino mice by administering low doses of kainic acid on the left cerebellar hemisphere. Using electrocorticography and electromyography, we investigated the power spectral densities, cortico-muscular, and interhemispheric coherence between the right and left motor cortices, before and during dystonia, for five consecutive days. Mice displayed lateralized abnormal motor signs, a reduced general locomotor activity, and a high score of dystonia. The results showed a progressive interhemispheric coherence decrease in low-frequency bands (delta, theta, beta) during the first 3 days. The cortico-muscular coherence of the affected side had a significant increase in gamma bands on days 3 and 4. In conclusion, lateralized cerebellar dysfunction during dystonia was associated with a loss of connectivity in the motor cortices, suggesting a possible cortical compensation to the initial disturbances induced by cerebellar left hemisphere kainate activation by blocking the propagation of abnormal oscillations to the healthy hemisphere. However, the cerebellum is part of several overly complex circuits, therefore other mechanisms can still be involved in this phenomenon.

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Multifocal Noninvasive Magnetic Stimulation of the Primary Motor Cortex in Type 1 Myotonic Dystrophy –A Proof of Concept Pilot Study

Journal of Neuromuscular Diseases ◽

10.3233/jnd-210690 ◽

2021 ◽

pp. 1-10

Author(s):

Ericka Greene ◽

Jason Thonhoff ◽

Blessy S. John ◽

David B. Rosenfield ◽

Santosh A. Helekar

Keyword(s):

Motor Cortex ◽

Myotonic Dystrophy ◽

Muscle Function ◽

Magnetic Stimulation ◽

Primary Motor Cortex ◽

Repetitive Transcranial Magnetic Stimulation ◽

Compound Muscle Action Potential ◽

Sham Stimulation ◽

Stimulation Of

Background: Repeated neuromuscular electrical stimulation in type 1 Myotonic Dystrophy (DM1) has previously been shown to cause an increase in strength and a decrease in hyperexcitability of the tibialis anterior muscle. Objective: In this proof-of-principle study our objective was to test the hypothesis that noninvasive repetitive transcranial magnetic stimulation of the primary motor cortex (M1) with a new portable wearable multifocal stimulator causes improvement in muscle function in DM1 patients. Methods: We performed repetitive stimulation of M1, localized by magnetic resonance imaging, with a newly developed Transcranial Rotating Permanent Magnet Stimulator (TRPMS). Using a randomized within-patient placebo-controlled double-blind TRPMS protocol, we performed unilateral active stimulation along with contralateral sham stimulation every weekday for two weeks in 6 adults. Methods for evaluation of muscle function involved electromyography (EMG), hand dynamometry and clinical assessment using the Medical Research Council scale. Results: All participants tolerated the treatment well. While there were no significant changes clinically, EMG showed significant improvement in nerve stimulus-evoked compound muscle action potential amplitude of the first dorsal interosseous muscle and a similar but non-significant trend in the trapezius muscle, after a short exercise test, with active but not sham stimulation. Conclusions: We conclude that two-week repeated multifocal cortical stimulation with a new wearable transcranial magnetic stimulator can be safely conducted in DM1 patients to investigate potential improvement of muscle strength and activity. The results obtained, if confirmed and extended by future safety and efficacy trials with larger patient samples, could offer a potential supportive TRPMS treatment in DM1.

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Resting state alpha oscillatory activity is a valid and reliable marker of schizotypy

Scientific Reports ◽

10.1038/s41598-021-89690-7 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Jelena Trajkovic ◽

Francesco Di Gregorio ◽

Francesca Ferri ◽

Chiara Marzi ◽

Stefano Diciotti ◽

...

Keyword(s):

At Risk ◽

Resting State ◽

Right Hemisphere ◽

Normal Population ◽

Alpha Activity ◽

Oscillatory Activity ◽

Loop Current ◽

Clinical Tool ◽

Reliable Marker ◽

The Right

AbstractSchizophrenia is among the most debilitating neuropsychiatric disorders. However, clear neurophysiological markers that would identify at-risk individuals represent still an unknown. The aim of this study was to investigate possible alterations in the resting alpha oscillatory activity in normal population high on schizotypy trait, a physiological condition known to be severely altered in patients with schizophrenia. Direct comparison of resting-state EEG oscillatory activity between Low and High Schizotypy Group (LSG and HSG) has revealed a clear right hemisphere alteration in alpha activity of the HSG. Specifically, HSG shows a significant slowing down of right hemisphere posterior alpha frequency and an altered distribution of its amplitude, with a tendency towards a reduction in the right hemisphere in comparison to LSG. Furthermore, altered and reduced connectivity in the right fronto-parietal network within the alpha range was found in the HSG. Crucially, a trained pattern classifier based on these indices of alpha activity was able to successfully differentiate HSG from LSG on tested participants further confirming the specific importance of right hemispheric alpha activity and intrahemispheric functional connectivity. By combining alpha activity and connectivity measures with a machine learning predictive model optimized in a nested stratified cross-validation loop, current research offers a promising clinical tool able to identify individuals at-risk of developing psychosis (i.e., high schizotypy individuals).

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