Neuroplastic effects of transcranial alternating current stimulation (tACS): from mechanisms to clinical trials

Frontiers in Human Neuroscience, Journal Year: 2025, Volume and Issue: 19

Published: March 12, 2025

Transcranial alternating current stimulation (tACS) is a promising non-invasive neuromodulation technique with the potential for inducing neuroplasticity and enhancing cognitive clinical outcomes. A unique feature of tACS, compared to other modalities, that it modulates brain activity by entraining neural oscillations an externally applied current. While many studies have focused on online effects during stimulation, growing evidence suggests tACS can induce sustained after-effects, which emphasizes long-term neurophysiological changes, essential therapeutic applications. In first part this review, we discuss how after-effects could be mediated four non-mutually exclusive mechanisms. First, spike-timing-dependent plasticity (STDP), where timing pre- postsynaptic spikes strengthens or weakens synaptic connections. Second, spike-phase coupling oscillation phase as mediators plasticity. Third, homeostatic plasticity, emphasizing importance operate within dynamic physiological ranges. Fourth, state-dependent highlights state in modulatory tACS. second applications trials targeting neurological psychiatric disorders, including major depressive disorder, schizophrenia, Parkinson’s disease, Alzheimer’s disease. Evidence repeated sessions, optimized individual oscillatory frequencies combined behavioral interventions, may result lasting enhance However, critical challenges remain, need personalized dosing, improved modeling, systematic investigation effects. conclusion, review mechanisms translational bridging basic neuroscience research optimize its use tool.

Language: Английский

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Beyond Mechanism—Extending Our Concepts of Causation in Neuroscience

European Journal of Neuroscience, Journal Year: 2025, Volume and Issue: 61(5)

Published: March 1, 2025

ABSTRACT In neuroscience, the search for causes of behaviour is often just taken to be neural mechanisms. This view typically involves three forms causal reduction: first, from ontological level cognitive processes that mechanisms; second, activity whole brain isolated parts; and third, a consideration temporally extended, historical focus on synchronic states. While modern neuroscience has made impressive progress in identifying mechanisms, providing unprecedented real‐time control behaviour, we contend this does not amount full explanation. particular, there an attendant danger eliminating our explanatory framework, even organism itself. To fully understand need what happens when different neurons are activated, but why those things happen . paper, introduce range well‐developed, non‐reductive, extended notions causality philosophy, which neuroscientists may able draw order build more complete explanations behaviour. These include concepts criterial causation, triggering versus structuring causes, constraints, macroscopic historicity, semantic causation—all which, argue, can used undergird naturalistic understanding mental causation agent causation. can, collectively, help bring cognition itself back into picture, as unto itself, while still grounding respectable scientific terms.

Language: Английский

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Beyond mechanism – extending our concepts of causation in neuroscience

Published: June 26, 2024

In neuroscience, the search for causes of behavior is often just taken to be neural mechanisms. This view typically involves three forms causal reduction: first, from ontological level cognitive processes that mechanisms; second, activity whole brain isolated parts; and third, a consideration temporally extended, historical focus on synchronic states. While modern neuroscience has made impressive progress in identifying mechanisms, providing unprecedented real-time control behavior, we contend this does not amount full explanation. particular, there an attendant danger eliminating our explanatory framework, even organism itself. To fully understand need what happens when different neurons are activated, but why those things happen. paper, introduce range well developed, non-reductive, extended notions causality philosophy, which neuroscientists may able draw order build more complete casual explanation behavior. These include concepts criterial causation, triggering versus structuring causes, constraints, macroscopic historicity, semantic causation – all which, argue, can used undergird naturalistic understanding mental agent causation. can, collectively, help bring cognition itself back into picture, as unto itself, while still grounding respectable scientific terms.

Language: Английский

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Mental causation: an evolutionary perspective

Frontiers in Psychology, Journal Year: 2024, Volume and Issue: 15

Published: April 29, 2024

The relationship between consciousness and individual agency is examined from a bottom-up evolutionary perspective, an approach somewhat different other ways of dealing with the issue, but one relevant to question animal consciousness. Two are identified that would decouple two, allowing limited kind exist without agency: (1) reflex pathways incorporate conscious sensations as intrinsic component (InCs), (2) reflexes consciously conditioned dependent on synaptic plasticity not memory (CCRs). Whether InCs CCRs more than hypothetical constructs clear, in any case theories where depends directly EM field-based effects. Consciousness agency, we experience it, then belongs third category allows for deliberate choice alternative actions (DCs), key difference this CCR-level DCs require access explicit systems whereas do not. nevertheless useful heuristic standpoint conceptual model how inputs could act refine routine behaviors while evolution optimize phenomenal (i.e., qualia) absence counterintuitive result. However, so long required precondition memory-dependent DC-level processes, later have evolved first. If so, adaptive benefit when it first may be linked much role plays encoding memories function. possibility theoretical construct, played consciousness, argues against focussed exclusively higher-order functions appropriate way deal evolved, develops early postnatal period life, or experiences animals ourselves. An perspective also resolves problem free will, best treated property species rather individuals belonging whereas, contrast, attribute individuals.

Language: Английский

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Dissociating Contributions of Theta and Alpha Oscillations from Aperiodic Neural Activity in Human Visual Working Memory

bioRxiv (Cold Spring Harbor Laboratory), Journal Year: 2024, Volume and Issue: unknown

Published: Dec. 17, 2024

Abstract While visual working memory (WM) is strongly associated with reductions in occipitoparietal 8-12 Hz alpha power, the role of 4-7 frontal midline theta power less clear, both increases and decreases widely reported. Here, we test hypothesis that this paradox can be explained by non-oscillatory, aperiodic neural activity dynamics. Because traditional time-frequency analyses electroencephalopgraphy (EEG) data conflate oscillations activity, event-related changes manifest as task-related apparent oscillations, even when none are present. Reanalyzing EEG from two WM experiments (n = 74), leveraging spectral parameterization, found systematic load, replicated classic alpha, but not theta, oscillatory effects after controlling for changes. Aperiodic decreased during retention, further flattened over cortex an increase load. After these dynamics, aperiodic-adjusted increasing In contrast, increased because reduces more, it falsely appears though “oscillatory” (e.g., bandpower) reduced. Furthermore, only a minority participants (31/74) had detectable degree oscillations. These results offer potential resolution to where studies show contrasting We identify novel dynamics human mask play cognition behavior. Significance statement Working Memory our ability hold information mind without being present external environment. Years research focused on brain discover mechanisms WM. specifically look at measured scalp their significance supporting challenge earlier findings regarding analysis approach, while replicating oscillation findings. involved WM, regions task-general manner, anterior reduced number items remembered. Thus, have identified

Language: Английский

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