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LTD-like plasticity of the human primary motor cortex can be reversed by γ-tACS
Cortical oscillatory activities play a role in regulating several brain functions in humans. However, whether motor resonant oscillations (i.e. β and γ) modulate long-term depression (LTD)-like plasticity of the primary motor cortex (M1) is still unclear.After-effects of 10 Hz tACS over the prefrontal cortex on phonological word decisions
Previous work in the language domain has shown that 10 Hz rTMS of the left or right posterior inferior frontal gyrus (pIFG) in the prefrontal cortex impaired phonological decision-making, arguing for a causal contribution of the bilateral pIFG to phonological processing. However, the neurophysiological correlates of these effects are unclear. The present study addressed the question whether neural activity in the prefrontal cortex could be modulated by 10 Hz tACS and how this would affect phonological decisions.Direction of TDCS current flow in human sensorimotor cortex influences behavioural learning
Recent studies have shown that neurophysiological outcomes of transcranial direct current stimulation (TDCS) are influenced by current flow in brain regions between the electrodes, and in particular the orientation of current flow relative to the cortical surface.Motor training modulates intracortical inhibitory dynamics in motor cortex during movement preparation
The primary motor cortex (M1) has a vital role to play in the learning of novel motor skills. However, the physiological changes underpinning this learning, particularly in terms of dynamic changes during movement preparation, are incompletely understood. In particular, a substantial decrease in resting gamma-amino butyric acid (GABA) activity, i.e. a release of resting inhibition, is seen within M1 as a subject prepares to move. Although there is evidence that a decrease in resting inhibition occurs within M1 during motor learning it is not known whether the pre-movement “release” of GABAergic inhibition is modulated during skill acquisition.Vagus nerve stimulation intensity influences motor cortex plasticity
Vagus nerve stimulation (VNS) paired with forelimb motor training enhances reorganization of movement representations in the motor cortex. Previous studies have shown an inverted-U relationship between VNS intensity and plasticity in other brain areas, such that moderate intensity VNS yields greater cortical plasticity than low or high intensity VNS. However, the relationship between VNS intensity and plasticity in the motor cortex is unknown.Interhemispheric cortico-cortical paired associative stimulation of the prefrontal cortex jointly modulates frontal asymmetry and emotional reactivity
As advances in neuroimaging further our understanding of the brain's functional connectivity, neuropsychology has moved away from a regional approach of attributing behavior to a specific region towards a network approach, attributing behavior to interconnected regions. A prime example of this is the suggested relevance of frontal asymmetry of the lateral prefrontal cortex (LPFC) in emotional processing. Yet, while neuroimaging defines relevant networks, it can only establish correlations and not causality.Modulation of the Direction and Magnitude of Hebbian Plasticity in Human Motor Cortex by Stimulus Intensity and Concurrent Inhibition
One of the most fascinating and important properties of the mammalian brain is its remarkable capacity for plasticity. Synaptic plasticity is considered to be the primary neuronal substrate for learning and memory [1]. As predicted in Hebb's postulate of associative plasticity in 1949 [2], synapses are strengthened if presynaptic activity precedes and contributes to postsynaptic firing, referred to as long term potentiation (LTP) [3], and weakened if the order is reversed, termed long term depression (LTD) [4].Transcranial Direct Current Stimulation for the Treatment of Chronic Tinnitus: A Randomized Controlled Study
Tinnitus is an often disabling condition for which there is no effective therapy. Current research suggests that tinnitus may develop due to maladaptive plastic changes and altered activity in the auditory and prefrontal cortex. Transcranial direct current stimulation (tDCS) modulates brain activity and has been shown to transiently suppress tinnitus in trials.Neurochemical Modulation in Posteromedial Default-mode Network Cortex Induced by Transcranial Magnetic Stimulation
The Default Mode Network (DMN) is severely compromised in several psychiatric and neurodegenerative disorders where plasticity alterations are observed. Glutamate and GABA are the major excitatory and inhibitory brain neurotransmitters respectively and are strongly related to plasticity responses and large-scale network expression.TMS Brain Mapping in Less Than Two Minutes
Transcranial magnetic stimulation (TMS) corticospinal excitability maps are a valuable tool to study plasticity in the corticospinal tract. Traditionally, data acquisition for a single map is time consuming, limiting the method's applicability when excitability changes quickly, such as during motor learning, and in clinical investigations where assessment time is a limiting factor.Variability in Response to Transcranial Direct Current Stimulation of the Motor Cortex
Responses to a number of different plasticity-inducing brain stimulation protocols are highly variable. However there is little data available on the variability of response to transcranial direct current stimulation (TDCS).Characterizing the Mechanisms of Central and Peripheral Forms of Neurostimulation in Chronic Dysphagic Stroke Patients
Swallowing problems following stroke may result in increased risk of aspiration pneumonia, malnutrition, and dehydration.Induction of Late LTP-Like Plasticity in the Human Motor Cortex by Repeated Non-Invasive Brain Stimulation
Non-invasive brain stimulation enables the induction of neuroplasticity in humans, however, with so far restricted duration of the respective cortical excitability modifications. Conventional anodal transcranial direct current stimulation (tDCS) protocols including one stimulation session induce NMDA receptor-dependent excitability enhancements lasting for about 1 h.
