Journal of neurophysiology
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Detecting errors in one's own actions, and in the actions of others, is a crucial ability for adaptable and flexible behavior. Studies show that specific EEG signatures underpin the monitoring of observed erroneous actions (error-related negativity, error positivity, mid-frontal theta oscillations). However, the majority of studies on action observation used sequences of trials where erroneous actions were less frequent than correct actions. ⋯ NEW & NOTEWORTHY Activation of the performance-monitoring system (PMS) is typically investigated when errors in a sequence are comparatively rare. However, whether the PMS is activated by errors per se or by their infrequency is not known. Combining EEG-virtual reality techniques, we found that observing frequent (70%) action errors performed by avatars elicits electrocortical error signatures suggesting that deviation from the prediction of how learned actions should correctly deploy, rather than its frequency, is coded in the PMS.
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Intracerebral hemorrhage (ICH) is a devastating disease worldwide with increasing mortality. The present study investigated whether minocycline was neuroprotective and induced M2 microglial polarization via upregulation of the TrkB/BDNF pathway after ICH. ICH was induced via injection of autologous blood into 150 Sprague-Dawley rats. ⋯ This study demonstrated for the first time that minocycline promoted M2 microglia polarization via upregulation of the TrkB/BDNF pathway and promoted neurogenesis after ICH. This study contributes to our understanding of the therapeutic potential of minocycline in ICH. NEW & NOTEWORTHY The present study gives several novel points: 1) Minocycline promotes neurogenesis after intracerebral hemorrhage in rats. 2) Minocycline induces activated M1 microglia into M2 neurotrophic phenotype. 3) M2 microglia secreting BDNF remodel the damaged neurocircuit.
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The pursuit of a physiological indicator of noxious stimulation is desirable as it has the potential to provide mechanistic information regarding acute pain and may ultimately improve pain management strategies. Currently, there are no specific neurophysiological markers of pain to evaluate treatments. Recent attempts to identify neural correlates of pain have focused on different neuroimaging modalities. The purpose of this review is to discuss common neuroimaging techniques and findings thus far.
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Parkinson's disease is associated with altered neural activity in the motor cortex. Chronic high-frequency deep brain stimulation (DBS) of the subthalamic nucleus (STN) is effective in suppressing parkinsonian motor symptoms and modulates cortical activity. However, the anatomical pathways responsible for STN DBS-mediated cortical modulation remain unclear. ⋯ The short-latency response occurs as a result of antidromic activation of the hyperdirect pathway comprising corticosubthalamic axons. However, the neural origins of intermediate- and long-latency responses remain elusive, and the dominant view is that these are produced through the orthodromic pathway (basal ganglia-thalamus-cortex). By combining in vivo electrophysiology with computational modeling, we demonstrate that antidromic activation of the cortico-thalamic-cortical pathway is sufficient to generate the intermediate- and long-latency cortical responses to STN DBS.
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Randomized Controlled Trial
Dose response of somatosensory cortex repeated anodal transcranial direct current stimulation on vibrotactile detection: a randomized sham-controlled trial.
This randomized sham-controlled trial investigated anodal transcranial direct current stimulation (tDCS) over the somatosensory cortex contralateral to hand dominance for dose-response (1 mA, 20 min × 5 days) effects on vibrotactile detection thresholds (VDT). VDT was measured before and after tDCS on days 1, 3, and 5 for low- (30 Hz) and high-frequency (200 Hz) vibrations on the dominant and nondominant hands in 29 healthy adults (mean age = 22.86 yr; 15 men, 14 women). Only the dominant-hand 200-Hz VDT displayed statistically significant medium effect size improvement for mixed-model analysis of variance time-by-group interaction for active tDCS compared with sham. ⋯ In conclusion, anodal tDCS at 1 mA, 20 min × 5 days on the dominant sensory cortex can modulate a linear improvement of dominant-hand high-frequency VDT but not low-frequency or nondominant-hand VDT. NEW & NOTEWORTHY Repeated weak anodal transcranial direct current stimulation (1 mA, 20 min) on the dominant sensory cortex provides linear improvement in dominant-hand high-frequency vibration detection thresholds. No effects were observed for low-frequency or nondominant-hand vibration detection thresholds.