Entrainment and Spike-Timing Dependent Plasticity – A Review of Proposed Mechanisms of Transcranial Alternating Current Stimulation

Frontiers in Systems Neuroscience, Journal Year: 2022, Volume and Issue: 16

Published: Feb. 24, 2022

Specific frequency bands of neural oscillations have been correlated with a range cognitive and behavioral effects (e.g., memory attention). The causal role specific frequencies may be investigated using transcranial alternating current stimulation (tACS), non-invasive brain method. TACS involves applying sinusoidal between two or more electrodes attached on the scalp, above regions that are implicated in processes interest. theorized mechanisms by which tACS affects implications for exact used, as well its anticipated effects. This review outlines main thought to underlie - entrainment, spike-timing dependent plasticity (STDP). Entrainment suggests stimulated synchronizes ongoing oscillations, is most effective when at close endogenous targeted network. STDP leads synaptic changes based timing neuronal firing target According principles STDP, strength increase pre-synaptic events occur prior post-synaptic (referred long-term potentiation, LTP). Conversely, events, synapses weakened depression, LTD). In this review, we summarize theoretical frameworks critically evidence each hypothesis. We also discuss whether mechanism alone can account combined necessary.

Language: Английский

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Evidence of a large current of transcranial alternating current stimulation directly to deep brain regions

Molecular Psychiatry, Journal Year: 2023, Volume and Issue: 28(12), P. 5402 - 5410

Published: July 19, 2023

Abstract Deep brain regions such as hippocampus, insula, and amygdala are involved in neuropsychiatric disorders, including chronic insomnia depression. Our recent reports showed that transcranial alternating current stimulation (tACS) with a of 15 mA frequency 77.5 Hz, delivered through montage the forehead both mastoids was safe effective intervening depression over 8 weeks. However, there is no physical evidence to support whether large tACS can send electrical currents deep tissue awake humans. Here, we directly recorded local field potentials (LFPs) insula at different strengths (1 mA) 11 adult patients drug-resistant epilepsy implanted stereoelectroencephalography (SEEG) electrodes who received Hz from 1 for five minutes each total 40 min. For additional 55 min were applied add up 60 Linear regression analysis revealed average LFPs remaining contacts on sides patient statistically associated given ( p < 0.05–0.01), except left one subject = 0.053). Alternating greater than 7 required produce significant differences three compared 0 0.05). The remained after adjusting multiple comparisons study provides direct specific procedures capable delivering tissues, opening realistic avenue modulating or treating disorders amygdala.

Language: Английский

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Hallmarks of primary headache: part 1 – migraine

The Journal of Headache and Pain, Journal Year: 2024, Volume and Issue: 25(1)

Published: Oct. 31, 2024

Migraine is a common disabling conditions which, globally, affects 15.2% of the population. It second cause health loss in terms years lived with disability, first among women. Despite being so common, it poorly recognised and too often undertreated. Specialty centres neurologists specific expertise on headache disorders have knowledge to provide care: however, those who do not regularly treat patients migraine will benefit from synopsis most relevant updated information about this condition. This paper presents comprehensive view hallmarks migraine, genetics diagnostic markers, up treatments societal impact, reports elements that identify features.

Language: Английский

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The cerebellum and the Mirror Neuron System: A matter of inhibition? From neurophysiological evidence to neuromodulatory implications. A narrative review

Neuroscience & Biobehavioral Reviews, Journal Year: 2024, Volume and Issue: 164, P. 105830 - 105830

Published: July 26, 2024

Mirror neurons show activity during both the execution (AE) and observation of actions (AO). The Neuron System (MNS) could be involved motor imagery (MI) as well. Extensive research suggests that cerebellum is interconnected with MNS may critically in its activities. We gathered evidence on cerebellum's role functions, theoretically experimentally. Evidence shows plays a major AO MI lesions impair functions likely because, by modulating cortical inhibitory interneurons mirror properties, contribute to visuomotor matching, which fundamental for shaping properties. Indeed, strengthen sensory-motor patterns minimise discrepancy between predicted actual outcome, AE AO. Furthermore, through connections hippocampus, might internal simulations programs MI. Finally, cerebellar neuromodulation improve impact activity, we explored potential neurophysiological neurorehabilitation implications.

Language: Английский

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Transcranial Electrical Stimulation generates electric fields in deep human brain structures

Brain stimulation, Journal Year: 2021, Volume and Issue: 15(1), P. 1 - 12

Published: Nov. 4, 2021

Language: Английский

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Neurobiological After-Effects of Low Intensity Transcranial Electric Stimulation of the Human Nervous System: From Basic Mechanisms to Metaplasticity

Frontiers in Neurology, Journal Year: 2021, Volume and Issue: 12

Published: Feb. 15, 2021

Non-invasive low-intensity transcranial electrical stimulation (tES) of the brain is an evolving field that has brought remarkable attention in past few decades for its ability to directly modulate specific functions. Neurobiological after-effects tES seems be related changes neuronal and synaptic excitability plasticity, however mechanisms are still far from being elucidated. We aim review recent results vitro vivo studies highlight molecular cellular direct (tDCS) alternating (tACS) current stimulation. Changes membrane potential neural synchronization explain ongoing short-lasting effects tES, while induced existing proteins new protein synthesis required long-lasting plastic (LTP/LTD). Glial cells, supporting elements, now considered constitutive part synapse might contribute plasticity. This brings into focus neurobiological tDCS tACS studies, both animals humans, highlighting possible pathways development targeted therapeutic applications.

Language: Английский

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Evidence of Neuroplastic Changes after Transcranial Magnetic, Electric, and Deep Brain Stimulation

Brain Sciences, Journal Year: 2022, Volume and Issue: 12(7), P. 929 - 929

Published: July 15, 2022

Electric and magnetic stimulation of the human brain can be used to excite or inhibit neurons. Numerous methods have been designed over years for this purpose with various advantages disadvantages that are topic review. Deep (DBS) is most direct focal application electric impulses tissue. Electrodes placed in order modulate neural activity correct parameters pathological oscillation circuits such as their amplitude frequency. Transcranial (TMS) a non-invasive alternative stimulator generating field coil scalp induces an which, turn, interacts ongoing activity. Depending upon parameters, excitation inhibition achieved. (tES) applies fields spread along skull reach brain, thus, limiting current strength avoid skin sensations cranial muscle pain. Therefore, tES only considered subthreshold, i.e., it does not directly elicit neuronal action potentials. In review, we collect hints neuroplastic changes modulation behavior, evolution clinical signs symptoms response stimulation. Possible mechanisms discussed, future paradigms suggested.

Language: Английский

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Noninvasive Brain Stimulation for Neurorehabilitation in Post-Stroke Patients

Brain Sciences, Journal Year: 2023, Volume and Issue: 13(3), P. 451 - 451

Published: March 6, 2023

Characterized by high morbidity, mortality, and disability, stroke usually causes symptoms of cerebral hypoxia due to a sudden blockage or rupture brain vessels, it seriously threatens human life health. Rehabilitation is the essential treatment for post-stroke patients suffering from functional impairments, through which hemiparesis, aphasia, dysphagia, unilateral neglect, depression, cognitive dysfunction can be restored various degrees. Noninvasive stimulation (NIBS) popular neuromodulatory technology rehabilitation focusing on local cortex, improve clinical functions regulating excitability corresponding neurons. Increasing evidence has been obtained application NIBS, especially repetitive transcranial magnetic (rTMS) direct current (tDCS). However, without standardized protocol, existing studies NIBS show wide variation in terms site, frequency, intensity, dosage, other parameters. Its neurorehabilitation still limited. With advances neuronavigation technologies, near-infrared spectroscopy, MRI, specific regions precisely located stimulation. On basis our further understanding neural circuits, neuromodulation also evolved single-target co-stimulation two more targets, even circuits network. The present study aims review findings research, discuss future directions application, finally promote use rehabilitation.

Language: Английский

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Cognitive and Neuropathophysiological Outcomes of Gamma-tACS in Dementia: A Systematic Review

Neuropsychology Review, Journal Year: 2023, Volume and Issue: 34(1), P. 338 - 361

Published: March 6, 2023

Abstract Despite the numerous pharmacological interventions targeting dementia, no disease-modifying therapy is available, and prognosis remains unfavorable. A promising perspective involves tackling high-frequency gamma-band (> 30 Hz) oscillations involved in hippocampal-mediated memory processes, which are impaired from early stages of typical Alzheimer’s Disease (AD). Particularly, positive effects entrainment on mouse models AD have prompted researchers to translate such findings into humans using transcranial alternating current stimulation (tACS), a methodology that allows endogenous cortical frequency-specific manner. This systematic review examines state-of-the-art use gamma-tACS Mild Cognitive Impairment (MCI) dementia patients shed light its feasibility, therapeutic impact, clinical effectiveness. search two databases yielded 499 records resulting 10 included studies total 273 patients. The results were arranged single-session multi-session protocols. Most demonstrated cognitive improvement following gamma-tACS, some showed neuropathological markers, suggesting feasibility these anyhow far strong evidence available for models. Nonetheless, small number their wide variability terms aims, parameters, measures, make it difficult draw firm conclusions. We discuss methodological limitations studies, proposing possible solutions future avenues improve research dementia.

Language: Английский

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A novel non-invasive brain stimulation technique: “Temporally interfering electrical stimulation”

Frontiers in Neuroscience, Journal Year: 2023, Volume and Issue: 17

Published: Jan. 27, 2023

For decades, neuromodulation technology has demonstrated tremendous potential in the treatment of neuropsychiatric disorders. However, challenges such as being less intrusive, more concentrated, using energy, and better public acceptance, must be considered. Several novel optimized methods are thus urgently desiderated to overcome these barriers. In specific, temporally interfering (TI) electrical stimulation was pioneered 2017, which used a low-frequency envelope waveform, generated by superposition two high-frequency sinusoidal currents slightly different frequency, stimulate specific targets inside brain. TI holds advantages both spatial targeting non-invasive character. The ability activate deep pathogenic without surgery is intriguing, it expected employed treat some neurological or psychiatric Recently, efforts have been undertaken investigate qualities translation application via computational modeling animal experiments. This review detailed most recent scientific developments field stimulation, with goal serving reference for future research.

Language: Английский

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