Yavuz, Sükrü Utku

[["dc.bibliographiccitation.firstpage","37"],["dc.bibliographiccitation.journal","Acta Physiologica"],["dc.bibliographiccitation.lastpage","38"],["dc.bibliographiccitation.volume","215"],["dc.contributor.author","Yavuz, Utku Suekrue"],["dc.contributor.author","Negro, Francesco"],["dc.contributor.author","Sebik, Oguz"],["dc.contributor.author","Holobar, Ales"],["dc.contributor.author","Froemmel, Cornelius"],["dc.contributor.author","Turker, Kemal S."],["dc.contributor.author","Farina, Dario"],["dc.date.accessioned","2018-11-07T09:49:23Z"],["dc.date.available","2018-11-07T09:49:23Z"],["dc.date.issued","2015"],["dc.identifier.isi","000364786400081"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/35500"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Wiley-blackwell"],["dc.publisher.place","Hoboken"],["dc.relation.issn","1748-1716"],["dc.relation.issn","1748-1708"],["dc.title","The new technique for accurate estimation of the spinal cord circuitry: recording reflex responses of large motor unit populations"],["dc.type","conference_abstract"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","4305"],["dc.bibliographiccitation.issue","19"],["dc.bibliographiccitation.journal","The Journal of Physiology"],["dc.bibliographiccitation.lastpage","4318"],["dc.bibliographiccitation.volume","593"],["dc.contributor.author","Yavuz, Utku Suekrue"],["dc.contributor.author","Negro, Francesco"],["dc.contributor.author","Sebik, Oguz"],["dc.contributor.author","Holobar, Ales"],["dc.contributor.author","Froemmel, Cornelius"],["dc.contributor.author","Turker, Kemal S."],["dc.contributor.author","Farina, Dario"],["dc.date.accessioned","2018-11-07T09:50:51Z"],["dc.date.available","2018-11-07T09:50:51Z"],["dc.date.issued","2015"],["dc.description.abstract","We propose and validate a non-invasive method that enables accurate detection of the discharge times of a relatively large number of motor units during excitatory and inhibitory reflex stimulations. High-density surface electromyography (HDsEMG) and intramuscular EMG (iEMG) were recorded from the tibialis anterior muscle during ankle dorsiflexions performed at 5%, 10% and 20% of the maximum voluntary contraction (MVC) force, in nine healthy subjects. The tibial nerve (inhibitory reflex) and the peroneal nerve (excitatory reflex) were stimulated with constant current stimuli. In total, 416 motor units were identified from the automatic decomposition of the HDsEMG. The iEMG was decomposed using a state-of-the-art decomposition tool and provided 84 motor units (average of two recording sites). The reflex responses of the detected motor units were analysed using the peri-stimulus time histogram (PSTH) and the peri-stimulus frequencygram (PSF). The reflex responses of the common motor units identified concurrently from the HDsEMG and the iEMG signals showed an average disagreement (the difference between number of observed spikes in each bin relative to the mean) of 8.2 +/- 2.2% (5% MVC), 6.8 +/- 1.0% (10% MVC) and 7.5 +/- 2.2% (20% MVC), for reflex inhibition, and 6.5 +/- 4.1%, 12.0 +/- 1.8% and 13.9 +/- 2.4%, for reflex excitation. There was no significant difference between the characteristics of the reflex responses, such as latency, amplitude and duration, for the motor units identified by both techniques. Finally, reflex responses could be identified at higher force (4 of the 9 subjects performed contraction up to 50% MVC) using HDsEMG but not iEMG, because of the difficulty in decomposing the iEMG at high forces. In conclusion, single motor unit reflex responses can be estimated accurately and non-invasively in relatively large populations of motor units using HDsEMG. This non-invasive approach may enable a more thorough investigation of the synaptic input distribution on active motor units at various force levels."],["dc.description.sponsorship","European Research Council (ERC) [267888]"],["dc.identifier.doi","10.1113/JP270635"],["dc.identifier.isi","000363090500002"],["dc.identifier.pmid","26115007"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/35792"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Wiley-blackwell"],["dc.relation.issn","1469-7793"],["dc.relation.issn","0022-3751"],["dc.title","Estimating reflex responses in large populations of motor units by decomposition of the high-density surface electromyogram"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","602"],["dc.bibliographiccitation.issue","3"],["dc.bibliographiccitation.journal","Journal of Neurophysiology"],["dc.bibliographiccitation.lastpage","612"],["dc.bibliographiccitation.volume","111"],["dc.contributor.author","Yavuz, S. Utku"],["dc.contributor.author","Mrachacz-Kersting, Natalie"],["dc.contributor.author","Sebik, Oguz"],["dc.contributor.author","Unver, M. Berna"],["dc.contributor.author","Farina, Dario"],["dc.contributor.author","Turker, Kemal S."],["dc.date.accessioned","2018-11-07T09:44:24Z"],["dc.date.available","2018-11-07T09:44:24Z"],["dc.date.issued","2014"],["dc.description.abstract","Reflex responses of tibialis anterior motor units to stretch stimuli were investigated in human subjects. Three types of stretch stimuli were applied (tap-like, ramp-and-hold, and half-sine stretch). Stimulus-induced responses in single motor units were analyzed using the classical technique, which involved building average surface electromyogram (SEMG) and peristimulus time histograms (PSTH) from the discharge times of motor units and peristimulus frequencygrams (PSF) from the instantaneous discharge rates of single motor units. With the use of SEMG and PSTH, the tap-like stretch stimulus induced five separate reflex responses, on average. With the same single motor unit data, the PSF technique indicated that the tap stimulus induced only three reflex responses. Similar to the finding using the tap-like stretch stimuli, ramp-and-hold stimuli induced several peaks and troughs in the SEMG and PSTH. The PSF analyses displayed genuine increases in discharge rates underlying the peaks but not underlying the troughs. Half-sine stretch stimuli induced a long-lasting excitation followed by a long-lasting silent period in SEMG and PSTH. The increase in the discharge rate, however, lasted for the entire duration of the stimulus and continued during the silent period. The results are discussed in the light of the fact that the discharge rate of a motoneuron has a strong positive linear association with the effective synaptic current it receives and hence represents changes in the membrane potential more directly and accurately than the other indirect measures. This study suggests that the neuronal pathway of the human stretch reflex does not include inhibitory pathways."],["dc.identifier.doi","10.1152/jn.00295.2013"],["dc.identifier.isi","000331215500015"],["dc.identifier.pmid","24225537"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/34386"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Amer Physiological Soc"],["dc.relation.issn","1522-1598"],["dc.relation.issn","0022-3077"],["dc.title","Human stretch reflex pathways reexamined"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","2863"],["dc.bibliographiccitation.issue","12"],["dc.bibliographiccitation.journal","Journal of Neurophysiology"],["dc.bibliographiccitation.lastpage","2872"],["dc.bibliographiccitation.volume","110"],["dc.contributor.author","D'Amico, Jessica M."],["dc.contributor.author","Yavuz, S. Utku"],["dc.contributor.author","Saracoglu, Ahmet"],["dc.contributor.author","Atis, Elif Sibel"],["dc.contributor.author","Gorassini, Monica A."],["dc.contributor.author","Turker, Kemal S."],["dc.date.accessioned","2018-11-07T09:16:54Z"],["dc.date.available","2018-11-07T09:16:54Z"],["dc.date.issued","2013"],["dc.description.abstract","In animals, sodium-and calcium-mediated persistent inward currents (PICs), which produce long-lasting periods of depolarization under conditions of low synaptic drive, can be activated in trigeminal motoneurons following the application of the monoamine serotonin. Here we examined if PICs are activated in human trigeminal motoneurons during voluntary contractions and under physiological levels of monoaminergic drive (e. g., serotonin and norepinephrine) using a paired motor unit analysis technique. We also examined if PICs activated during voluntary contractions are larger in participants who demonstrate involuntary chewing during sleep (bruxism), which is accompanied by periods of high monoaminergic drive. In control participants, during a slowly increasing and then decreasing isometric contraction, the firing rate of an earlier-recruited masseter motor unit, which served as a measure of synaptic input to a later-recruited test unit, was consistently lower during derecruitment of the test unit compared with at recruitment (Delta F = 4.6 +/- 1.5 imp/s). The Delta F, therefore, is a measure of the reduction in synaptic input needed to counteract the depolarization from the PIC to provide an indirect estimate of PIC amplitude. The range of Delta F values measured in the bruxer participants during similar voluntary contractions was the same as in controls, suggesting that abnormally high levels of monoaminergic drive are not continually present in the absence of involuntary motor activity. We also observed a consistent \"onion skin effect\" during the moderately sized contractions (<20% of maximal), whereby the firing rate of higher threshold motor units discharged at slower rates (by 4-7 imp/s) compared with motor units with relatively lower thresholds. The presence of lower firing rates in the more fatigue-prone, higher threshold trigeminal motoneurons, in addition to the activation of PICs, likely facilitates the activation of the masseter muscle during motor activities such as eating, nonnutritive chewing, clenching, and yawning."],["dc.identifier.doi","10.1152/jn.00536.2013"],["dc.identifier.isi","000328889700016"],["dc.identifier.pmid","24068753"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/28043"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Amer Physiological Soc"],["dc.relation.issn","1522-1598"],["dc.relation.issn","0022-3077"],["dc.title","Activation properties of trigeminal motoneurons in participants with and without bruxism"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","1746"],["dc.bibliographiccitation.issue","9"],["dc.bibliographiccitation.journal","Clinical Neurophysiology"],["dc.bibliographiccitation.lastpage","1753"],["dc.bibliographiccitation.volume","126"],["dc.contributor.author","Laine, C. M."],["dc.contributor.author","Yavuz, S. Utku"],["dc.contributor.author","D'Amico, J. M."],["dc.contributor.author","Gorassini, Monica A."],["dc.contributor.author","Turker, Kemal S."],["dc.contributor.author","Farina, Dario"],["dc.date.accessioned","2018-11-07T09:52:58Z"],["dc.date.available","2018-11-07T09:52:58Z"],["dc.date.issued","2015"],["dc.description.abstract","Objective: To determine if sleep bruxism is associated with abnormal physiological tremor of the jaw during a visually-guided bite force control task. Methods: Healthy participants and patients with sleep bruxism were given visual feedback of their bite force and asked to trace triangular target trajectories (duration = 20 s, peak force <35% maximum voluntary force). Bite force control was quantified in terms of the power spectra of force fluctuations, masseter EMG activity, and force-to-EMG coherence. Results: Patients had greater jaw force tremor at similar to 8 Hz relative to controls, along with increased masseter EMG activity and force-to-EMG coherence in the same frequency range. Patients also showed lower force-to-EMG coherence at low frequencies (<3 Hz), but greater coherence at high frequencies (20-40 Hz). Finally, patients had greater 6-10 Hz force tremor during periods of descending vs. ascending force, while controls showed no difference in tremor with respect to force dynamics. Conclusion: Patients with bruxism have abnormal jaw tremor when engaged in a visually-guided bite force task. Significance: Measurement of jaw tremor may aid in the detection/evaluation of bruxism. In light of previous literature, our results also suggest that bruxism is marked by abnormal or mishandled peripheral feedback from the teeth. (C) 2015 Published by Elsevier Ireland Ltd. on behalf of International Federation of Clinical Neurophysiology."],["dc.identifier.doi","10.1016/j.clinph.2014.11.022"],["dc.identifier.isi","000359319800017"],["dc.identifier.pmid","25533275"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/36233"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Elsevier Ireland Ltd"],["dc.relation.issn","1872-8952"],["dc.relation.issn","1388-2457"],["dc.title","Jaw tremor as a physiological biomarker of bruxism"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.journal","Acta Physiologica"],["dc.bibliographiccitation.volume","215"],["dc.contributor.author","Yavuz, Utku Suekrue"],["dc.contributor.author","Negro, Francesco"],["dc.contributor.author","Sebik, Oguz"],["dc.contributor.author","Froemmel, Cornelius"],["dc.contributor.author","Farina, Dario"],["dc.contributor.author","Turker, Kemal S."],["dc.date.accessioned","2018-11-07T09:49:23Z"],["dc.date.available","2018-11-07T09:49:23Z"],["dc.date.issued","2015"],["dc.format.extent","37"],["dc.identifier.isi","000364786400080"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/35501"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Wiley-blackwell"],["dc.publisher.place","Hoboken"],["dc.relation.issn","1748-1716"],["dc.relation.issn","1748-1708"],["dc.title","Discharge rate and synaptic noise affect reflex response regime of motor unit population"],["dc.type","conference_abstract"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]