Automatic inhibitory function in the human somatosensory and motor cortices: An MEG-MRS study

Cheng, Chia‐Hsiung; Tsai, Shau‐Wei; Liu, Chia Yih; Niddam, David M.

doi:10.1038/s41598-017-04564-1

Cited by 33 publications

(24 citation statements)

References 44 publications

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“…First, no habituation effects were observed on the evoked fields (Fig. 2), while habituation has been reported in studies with shorter inter-stimulus intervals (< 2 s) (Cheng et al, 2017;Hsiao et al, 2013). Second, conversely to what was found here, the influence from gating on beta oscillations have been shown to show higher synchronization for the first than for the second stimulation when stimulations are presented in pairs (Hsiao et al, 2013).…”

Section: Theta Beta and Gamma Increases After Expected Stimulationssupporting

confidence: 53%

Somatosensory responses to nothing: an MEG study of expectations during omission of tactile stimulations

Andersen

2018

Preprint

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The brain builds up expectations to future events based on the patterns of past events. This function has been studied extensively in the auditory and visual domains using various oddball paradigms, but only little exploration of this phenomenon has been done in the somatosensory domain. In this study, we explore how expectations of somatosensory stimulations are established and expressed in neural activity as measured with magnetoencephalography. Using tactile stimulations to the index finger, we compared conditions with actual stimulation to conditions with omitted stimulations, both of which were either expected or unexpected.Our results show that when a stimulation is expected but omitted, a time-locked response occurs ~135 ms subsequent to the expected stimulation. This somatosensory response to "nothing" was source localized to the secondary somatosensory cortex and to the insula. This provides novel evidence of the capability of the brain of millisecond time-keeping of somatosensory patterns across intervals of 3000 ms.Our results also show that when stimuli are repeated and expectations are established, there is associated activity in the theta and beta bands. These theta and beta band expressions of expectation were localized to the primary somatosensory area, inferior parietal cortex and cerebellum. Furthermore, there was gamma band activity in the right insula for the first stimulation after an omission, which indicates the detection of a new stimulation event after an expected pattern has been broken.Finally, our results show that cerebellum play a crucial role in predicting upcoming stimulation and in predicting when stimulation may begin again.

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Section: Theta Beta and Gamma Increases After Expected Stimulationssupporting

confidence: 53%

Somatosensory responses to nothing: an MEG study of expectations during omission of tactile stimulations

Andersen

2018

Preprint

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“…Similar studies of gamma oscillatory activity and GABA concentrations have been conducted in the motor system and these also replicated the established gamma-GABA link described in the visual cortex of humans ( Gaetz et al, 2011 ), and in some cases have extended this relationship to other spectral components of movement ( Hall et al, 2011 ; Muthukumaraswamy et al, 2013 ). However, of note, not all studies have replicated this gamma-GABA relationship in sensory systems ( Cheng et al, 2017 ; Cousijn et al, 2014 ). For example, a recent study by Cheng and colleagues evaluated the relationship between GABA concentration in the sensorimotor cortex and somatosensory gating ratios.…”

Section: Discussionmentioning

confidence: 99%

“…For example, a recent study by Cheng and colleagues evaluated the relationship between GABA concentration in the sensorimotor cortex and somatosensory gating ratios. They observed no significant association among the two variables, suggesting that at least some measures of sensory gating are not related to changes in GABA concentration ( Cheng et al, 2017 ). However, importantly, this study used the P35 time-domain response to compute gating ratios and the degree to which this response reflects gamma-frequency activity is unclear.…”

Section: Discussionmentioning

confidence: 99%

Methodological considerations for a better somatosensory gating paradigm: The impact of the inter-stimulus interval

et al. 2020

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Sensory gating (SG) is a neurophysiological phenomenon whereby the response to the second stimulus in a repetitive pair is attenuated. This filtering of irrelevant or redundant information is thought to preserve neural resources for more behaviorally-relevant stimuli and thereby reflect the functional inhibition of sensory input. Developing a SG paradigm in which optimal suppression of sensory input is achieved requires investigators to consider numerous parameters such as stimulus intensity, time between stimulus pairs, and the inter-stimulus interval (ISI) within each pair. While these factors have been well defined for the interrogation of auditory gating, the precise parameters for eliciting optimal gating in the somatosensory domain are far less understood. To address this, we investigated the impact of varying the ISI within each identical pair of stimuli on gating using magnetoencephalography (MEG). Specifically, 25 healthy young adults underwent paired-pulse electrical stimulation of the median nerve with increasing ISIs between 100 and 1000 ms (in 100 ms increments). Importantly, for correspondence with previous studies of somatosensory gating, both time-domain and oscillatory neural responses to somatosensory stimulation were evaluated. Our results indicated that gating of somatosensory input was optimal (i.e., best suppression) for trials with an ISI of 200–220 ms, as evidenced by the smallest gating ratios and through statistical modeling estimations of optimal suppression. Importantly, this was true irrespective of whether oscillatory or evoked neural activity was used to calculate SG. Interestingly, oscillatory metrics of gating calculated using peak gamma (30–75 Hz) power and frequency revealed more robust gating (i.e., smaller ratios) than those calculated using time-domain neural responses, suggesting that high frequency oscillations may provide a more sensitive measure of SG. These findings have important implications for the development of optimal protocols and analysis pipelines to interrogate SG and inhibitory processing with a higher degree of sensitivity and accuracy.

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“…Electrical stimulation was delivered to the right median nerve through an electrical stimulator (Konstant‐Strom Stimulator, Germany). Each pulse was 0.2 ms constant‐current square‐wave with an interstimulus interval (ISI) of 1.8–2.2 s. In this study, the stimulus intensity was set at 20% above the motor threshold to elicit a visible twitch of the abductor pollicis brevis muscles (Cheng & Lin, ; Cheng et al ., 2016a, 2017b). During the whole experiment, all the subjects received repetitive non‐painful electrical stimulation at the wrist while performing the tasks, that is Resting and Manipulation in the Experimental I, and Normal and Abnormal in the Experimental II.…”

Section: Methodsmentioning

confidence: 99%

Effects of observing normal and abnormal goal‐directed hand movements on somatosensory cortical activation

Cheng

2017

Eur J of Neuroscience

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Existing evidence indicates the importance of observing correct, normal actions on the motor cortical activities. However, the exact neurophysiological mechanisms, particularly in the somatosensory system, remain unclear. This study aimed to elucidate the effects of observing normal and abnormal hand movements on the contralateral primary somatosensory (cSI), contralateral (cSII) and ipsilateral (iSII) secondary somatosensory activities. Experiment I was designed to investigate the effects of motor outputs on the somatosensory processing, in which subjects were instructed to relax or manipulate a small cube. Experiment II was tailored to examine the somatosensory responses to the observation of normal (Normal) and abnormal (Abnormal) hand movements. The subjects received electrical stimulation to right median nerve and magnetoencephalography (MEG) recordings during the whole experimental period. Regional cortical activation and functional connectivity were analyzed. Compared to the resting condition, a reduction in cSI and an enhancement of SII activation was found when subjects manipulated a cube, suggesting the motor outputs have an influence on the somatosensory responses. Further investigation of the effects of observing different hand movements showed that cSII activity was significantly stronger in the Normal than Abnormal condition. Moreover, compared with Abnormal condition, a higher cortical coherence of cSI-iSII at theta bands and cSII-iSII at beta bands was found in Normal condition. Conclusively, the present results suggest stronger activation and enhanced functional connectivity within the somatosensory system during the observation of normal than abnormal hand movements. These findings also highlight the importance of viewing normal, correct hands movements in the stroke rehabilitation.

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Automatic inhibitory function in the human somatosensory and motor cortices: An MEG-MRS study

Cited by 33 publications

References 44 publications

Somatosensory responses to nothing: an MEG study of expectations during omission of tactile stimulations

Somatosensory responses to nothing: an MEG study of expectations during omission of tactile stimulations

Methodological considerations for a better somatosensory gating paradigm: The impact of the inter-stimulus interval

Effects of observing normal and abnormal goal‐directed hand movements on somatosensory cortical activation

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