Dipole orientation differs between high frequency oscillations and N20m current sources in human somatosensory evoked magnetic fields to median nerve stimulation

Ozaki, Isamu; Yaegashi, Yukoh; Kimura, Tomoaki; Baba, Masayuki; Matsunaga, M; Hashimoto, Isao

doi:10.1016/s0304-3940(01)02090-0

Cited by 18 publications

(7 citation statements)

References 12 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…HFOs are small wavelets with a frequency around 600 Hz superimposed on the N20 component of SEP. l-HFO are thought to depend on the activity of S1 inhibitory interneurons (Hashimoto et al , 1996, Curio, 2000, Jones et al , 2000, Klostermann et al , 2001, Ozaki et al , 2001, Ikeda et al , 2002, Gobbele et al , 2004, Ozaki et al , 2011 possibly producing feedforward inhibition of cortical pyramidal neurons (Ozaki et al , 2011). Since HF-RSS produced an increase in l-HFO, it is likely that excitability of S1 inhibitory interneurons was increased.…”

Section: Electrophysiological Resultsmentioning

confidence: 99%

High frequency somatosensory stimulation increases sensori-motor inhibition and leads to perceptual improvement in healthy subjects

Rocchi

Erro

Antelmi

et al. 2017

Clinical Neurophysiology

View full text Add to dashboard Cite

Objective: high frequency repetitive somatosensory stimulation (HF-RSS), which is a patterned electric stimulation applied to the skin through surface electrodes, improves two-point discrimination, somatosensory temporal discrimination threshold (STDT) and motor performance in humans.However, the mechanisms which underlie this changes are still unknown. In particular, we hypothesize that refinement of inhibition might be responsible for the improvement in spatial and temporal perception. Methods: fifteen healthy subjects underwent 45 minutes of HF-RSS. Before and after the intervention several measures of inhibition in the primary somatosensory area (S1), such as paired-pulse somatosensory evoked potentials (pp-SEP), high-frequency oscillations (HFO), and STDT were tested, as well as tactile spatial acuity and short intracortical inhibition (SICI). Results:HF-RSS increased inhibition in S1 tested by pp-SEP and HFO; these changes were correlated with improvement in STDT. HF-RSS also enhanced bumps detection, while there was no change in grating orientation test. Finally there was an increase in SICI, suggesting widespread changes in cortical sensorimotor interactions. Conclusions: these findings suggest that HF-RSS can improve spatial and temporal tactile abilities by increasing the effectiveness of inhibitory interactions in the somatosensory system. Moreover, HF-RSS induces changes in cortical sensorimotor interaction.Significance: HF-RSS is a repetitive electric stimulation technique able to modify the effectiveness of inhibitory circuitry in the somatosensory system and primary motor cortex. 4

show abstract

Section: Electrophysiological Resultsmentioning

confidence: 99%

High frequency somatosensory stimulation increases sensori-motor inhibition and leads to perceptual improvement in healthy subjects

Rocchi

Erro

Antelmi

et al. 2017

Clinical Neurophysiology

View full text Add to dashboard Cite

show abstract

“…The generators of HFO have been proposed as the thalamus, the thalamocortical fibers or postsynaptic activities in the primary sensory cortex (for a review see Curio, 2000). Early and late HFOs, i.e., the wavelets before and after the peak latency of the N20 as the initial cortical response, have been supposed to be separate since these two components differ in their responsiveness to various modulations (Ozaki et al, 2001; Ritter et al, 2008). The early part of the HFOs is presumably generated from action potentials of thalamocortical fibers (Klostermann et al, 1999; Curio, 2000; Gobbele et al, 2004).…”

Section: Introductionmentioning

confidence: 99%

“…Pyramidal “chattering” cells (Gray and McCormick, 1996), cortical fast-spiking inhibitory interneurons (Hashimoto et al, 1996) and thalamocortical relay cells (Curio, 2000) have been proposed as possible cell populations generating HFO. Supporters of the interneuron hypothesis propose that the late HFO represent the activities of combined vertically and horizontally oriented GABAergic inhibitory interneurons in somatosensory cortex (Hashimoto et al, 1996; Ozaki et al, 2001; Ozaki and Hashimoto, 2005, 2011). They rely on the divergence in the orientation of the dipoles between HFO source and underlying N20 source (Ozaki et al, 2001; Ozaki and Hashimoto, 2011).…”

Section: Introductionmentioning

confidence: 99%

“…Supporters of the interneuron hypothesis propose that the late HFO represent the activities of combined vertically and horizontally oriented GABAergic inhibitory interneurons in somatosensory cortex (Hashimoto et al, 1996; Ozaki et al, 2001; Ozaki and Hashimoto, 2005, 2011). They rely on the divergence in the orientation of the dipoles between HFO source and underlying N20 source (Ozaki et al, 2001; Ozaki and Hashimoto, 2011). …”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Early somatosensory processing in individuals at risk for developing psychoses

Hagenmuller

Theodoridou

Walitza

et al. 2014

Front. Behav. Neurosci.

View full text Add to dashboard Cite

Human cortical somatosensory evoked potentials (SEPs) allow an accurate investigation of thalamocortical and early cortical processing. SEPs reveal a burst of superimposed early (N20) high-frequency oscillations around 600 Hz. Previous studies reported alterations of SEPs in patients with schizophrenia. This study addresses the question whether those alterations are also observable in populations at risk for developing schizophrenia or bipolar disorders. To our knowledge to date, this is the first study investigating SEPs in a population at risk for developing psychoses. Median nerve SEPs were investigated using multichannel EEG in individuals at risk for developing bipolar disorders (n = 25), individuals with high-risk status (n = 59) and ultra-high-risk status for schizophrenia (n = 73) and a gender and age-matched control group (n = 45). Strengths and latencies of low- and high-frequency components as estimated by dipole source analysis were compared between groups. Low- and high-frequency source activity was reduced in both groups at risk for schizophrenia, in comparison to the group at risk for bipolar disorders. HFO amplitudes were also significant reduced in subjects with high-risk status for schizophrenia compared to healthy controls. These differences were accentuated among cannabis non-users. Reduced N20 source strengths were related to higher positive symptom load. These results suggest that the risk for schizophrenia, in contrast to bipolar disorders, may involve an impairment of early cerebral somatosensory processing. Neurophysiologic alterations in schizophrenia precede the onset of initial psychotic episode and may serve as indicator of vulnerability for developing schizophrenia.

show abstract

“…Movement interference reduces N20 amplitude with small effect on the HFOs (Klostermann et al, 2001;Inoue et al, 2002). Also, by means of dipole analysis, different sources have been found for each of them (Ozaki et al, 2001;Gobbele et al, 2004).…”

Section: Discussionmentioning

confidence: 89%

High frequency oscillations in the somatosensory evoked potentials (SSEP's) are mainly due to phase-resetting phenomena

Valencia

Alegre

Iriarte

et al. 2006

Journal of Neuroscience Methods

View full text Add to dashboard Cite

Dipole orientation differs between high frequency oscillations and N20m current sources in human somatosensory evoked magnetic fields to median nerve stimulation

Cited by 18 publications

References 12 publications

High frequency somatosensory stimulation increases sensori-motor inhibition and leads to perceptual improvement in healthy subjects

High frequency somatosensory stimulation increases sensori-motor inhibition and leads to perceptual improvement in healthy subjects

Early somatosensory processing in individuals at risk for developing psychoses

High frequency oscillations in the somatosensory evoked potentials (SSEP's) are mainly due to phase-resetting phenomena

Contact Info

Product

Resources

About