Journal of neurophysiology最新文献

{"title":"Unified measures quantifying intensity and similarity of pain and somatosensory percepts.","authors":"Eric J Earley, Malin Ramne, Johan Wessberg","doi":"10.1152/jn.00031.2025","DOIUrl":"10.1152/jn.00031.2025","url":null,"abstract":"","PeriodicalId":16563,"journal":{"name":"Journal of neurophysiology","volume":" ","pages":"292-302"},"PeriodicalIF":2.1,"publicationDate":"2025-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144310058","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Case studies in neuroscience: movement-related cortical stimulation to enhance corticospinal transmission in chronic incomplete spinal cord injury.","authors":"David A Cunningham, Christina V Oleson, P Hunter Peckham, Kevin L Kilgore","doi":"10.1152/jn.00083.2025","DOIUrl":"10.1152/jn.00083.2025","url":null,"abstract":"<p><p>Incomplete spinal cord injury (iSCI) disrupts signal transmission at the level of injury (LOI) and in higher brain structures, weakening intracortical circuits and impairing movement initiation. A potential approach to target intracortical circuits is to deliver transcranial magnetic stimulation (TMS) during motor intention, known as movement-related cortical stimulation (MRCS). We hypothesize that delivering TMS during motor intention will enhance corticospinal excitability (CE) and improve muscle activation below the LOI. One participant with chronic severe iSCI participated in a crossover study followed by five consecutive treatment sessions. First, we investigated the impact of TMS intensity (subthreshold vs. suprathreshold) on CE when delivered 50 ms before movement. The participant then received five consecutive days of MRCS with active subthreshold TMS for 15-20 min. <i>Experiment 1:</i> CE was assessed before and after sham, suprathreshold, and subthreshold MRCS (1-wk washout), targeting the abductor hallucis muscle. <i>Experiment 2</i>: CE and volitional motor unit recruitment were measured at baseline, the start of each session and 3- and 7-day follow-up. Corticomotor maps were assessed at baseline and post 3- and 7-day follow-up. Subthreshold MRCS increased CE compared with sham and suprathreshold MRCS. Five days of subthreshold MRCS increased CE, motor maps, and volitional motor unit recruitment, with improvements lasting up to the 3-day follow-up and remaining above baseline at <i>day 7</i>. These findings suggest that timed cortical stimulation with movement intention may enhance signal transmission in iSCI below the LOI. Future research is needed to determine if MRCS can prime intracortical circuitry before therapy to improve motor function.<b>NEW & NOTEWORTHY</b> We demonstrate that five consecutive days of movement-related cortical stimulation can enhance corticospinal excitability, expand motor maps, and improve volitional motor unit recruitment in a person with severe incomplete spinal cord injury. These results support the brain's adaptive capacity following spinal cord injury, despite limited motor drive to the muscle, and corroborate the potential to improve motor function by targeting higher-order networks during volitional motor intention with noninvasive brain stimulation.</p>","PeriodicalId":16563,"journal":{"name":"Journal of neurophysiology","volume":" ","pages":"397-406"},"PeriodicalIF":2.1,"publicationDate":"2025-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144560426","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Modulation of persistent inward currents in alpha motoneurons with joint angle depends on muscle length.","authors":"Valentin Goreau, Quentin Morvan, François Hug, Guillaume Le Sant, Raphaël Gross, Thomas Cattagni","doi":"10.1152/jn.00097.2025","DOIUrl":"https://doi.org/10.1152/jn.00097.2025","url":null,"abstract":"<p><p>During voluntary movement, activity of alpha motoneurons is modulated to account for changes in muscle force-generating capacity induced by variations in muscle length. To date, research has primarily focused on the modulation of ionotropic inputs, while the role of another key contributor to alpha motoneuron activity, persistent inward currents (PICs), has been largely overlooked. In this human study involoving young male participants (n=19), high-density surface electromyography signals were recorded from the gastrocnemius medialis and soleus muscles at different ankle positions, and subsequently decomposed into motor unit spiking activity. Metrics extracted from these spiking activities were used to estimate the respective contributions of PICs, neuromodulation, and inhibition to alpha motoneurons activity. To differentiate the impact of muscle length from muscle tension, we compared voluntary contractions performed at both similar relative torque levels and similar absolute torque levels across different ankle positions. Our results revealed that PIC-induced prolongation of motor unit discharges was reduced at longer muscle lengths, accompanied by increased inhibition. This effect was consistent across both relative and absolute torque conditions, supporting the hypothesis that muscle length is the primary driver of PICs modulation with change of position. These findings suggest that PICs may serve as an additional mechanism - likely related to inhibitory inputs - to regulate alpha motoneuron activity, ensuring adaptation to changes in muscle length.</p>","PeriodicalId":16563,"journal":{"name":"Journal of neurophysiology","volume":" ","pages":""},"PeriodicalIF":2.1,"publicationDate":"2025-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144540585","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Ineffective cues for contextual saccade adaptation.","authors":"Maxime Martel, Laurent Madelain","doi":"10.1152/jn.00148.2025","DOIUrl":"10.1152/jn.00148.2025","url":null,"abstract":"<p><p>Contextual saccadic adaptation is investigated through a variant of the double-step paradigm, where two directions of intrasaccadic steps are signaled by two cues. This enables the simultaneous induction of two distinct saccadic adaptations. Surprisingly, contextual adaptation is effective only with motor-related cues, whereas visual cues such as target color and shape do not elicit significant adaptation. We tested nine different contextual cues to signal intrasaccadic steps in a contextual double-step paradigm: visual stimulus duration, lateralization of a sound, various statistical regularities across trials, symbolic cues, starting location of the target, and the amplitude of the first step or the target color and shape. Robust systematic contextual learning was found under the amplitude and the starting location experiments, whereas no learning occurred with any other cues. This lack of contextual learning further confirms that the prediction of the intrasaccadic steps depends on the nature of the context. In two additional experiments replicating those using target color and shape, and symbolic cues, participants were periodically prompted to explicitly report the contextual cue they had just experienced. Again, no systematic contextual adaptation was observed despite participants achieving reporting the contextual cue accurately. This dissociation between perceptual reports and motor tasks involving the same visual information aligns with previous results on the constraints for contextual learning. The saccadic system, evolutionarily specialized for spatial targeting, exhibits selective learning that prioritizes localization cues, effectively ignoring nonmotor cues in its learning processes, even when such cues are explicitly perceived.<b>NEW & NOTEWORTHY</b> This study demonstrates that motor-related cues drive contextual saccadic adaptation, whereas purely perceptual cues fail to do so. We observed a dissociation between the ability to report nonmotor cues and their failure to induce contextual adaptation. The results underscore the importance of spatially relevant cues for guiding contextual saccadic adaptation. These findings deepen our understanding of the selective mechanisms underlying motor learning.</p>","PeriodicalId":16563,"journal":{"name":"Journal of neurophysiology","volume":" ","pages":"237-249"},"PeriodicalIF":2.1,"publicationDate":"2025-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144225755","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Spinal reflexes: a potential target for treating hemiparetic gait.","authors":"Russell L Hardesty, Helia Mojtabavi, Jonathan R Wolpaw","doi":"10.1152/jn.00211.2025","DOIUrl":"10.1152/jn.00211.2025","url":null,"abstract":"","PeriodicalId":16563,"journal":{"name":"Journal of neurophysiology","volume":" ","pages":"290-291"},"PeriodicalIF":2.1,"publicationDate":"2025-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144475690","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"From simple lab tasks to the virtual court: Bayesian integration in tennis.","authors":"Damian Beck, Stephan Zahno, Ralf Kredel, Ernst-Joachim Hossner","doi":"10.1152/jn.00434.2024","DOIUrl":"10.1152/jn.00434.2024","url":null,"abstract":"<p><p>Two decades of research suggest that humans integrate sensory information and prior expectations in a Bayesian way to guide behavior. However, although Bayesian integration provides a powerful framework for perception, cognition, and motor control, evidence is largely limited to simple lab tasks. In two experiments with 32 participants each, we show that predictive gaze behavior aligns with core Bayesian predictions in a complex sensorimotor task: returning tennis serves. Participants returned serves in an extended reality setup with unconstrained movements and task demands matching real tennis. They faced two opponents with distinct distributions of serve locations. We measured predictive gaze behavior and explicit judgments to assess participants' estimations of the ball-bounce location. In the second experiment, we increased visual uncertainty with higher ball speeds. Confirming Bayesian predictions, participants' gaze was biased toward the opponent's preferred serve locations, particularly when visual uncertainty was increased by higher ball speeds. Furthermore, we found a dynamic reliability-weighted integration on two timescales: <i>1</i>) on the timescale of a \"match\" (i.e., the experimental session), the prior effect grew with increasing experience of the opponent's preferred serve locations (i.e., with increasing reliability of prior information). <i>2</i>) On the timescale of a single serve, the prior affected early estimates of ball-bounce location (i.e., gaze behavior); however, these estimates were \"overwritten\" by incoming sensory inputs accumulated during ball flight. Our results demonstrate that Bayesian theory provides a principled explanation of how our sensorimotor system solves complex challenges at the limit of human performance, such as returning high-speed tennis serves.<b>NEW & NOTEWORTHY</b> This study tests Bayesian integration in a complex sensorimotor task: returning tennis serves. We found reliability-based prior-likelihood integration on two timescales: <i>1</i>) over a \"match\" (increasing reliability of prior information) and <i>2</i>) over a single serve (increasing reliability of sensory information). More generally, this study exemplifies how leveraging extended reality technology provides a means to reduce the internal versus external validity trade-off by studying motor control under real-world task demands while ensuring rigorous experimental control.</p>","PeriodicalId":16563,"journal":{"name":"Journal of neurophysiology","volume":" ","pages":"303-313"},"PeriodicalIF":2.1,"publicationDate":"2025-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144497344","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Muscle function and electromyography: (almost) 70 years since Doty and Bosma (1956).","authors":"Christopher J Mayerl, Rebecca Z German","doi":"10.1152/jn.00176.2025","DOIUrl":"10.1152/jn.00176.2025","url":null,"abstract":"<p><p>Swallowing, and dysphagia, the pathophysiology of swallowing, differ from most motor activities in that they are not readily observable without invasive imaging or measurement. Successful swallowing depends more on the precision of control and coordination with respiration than it does on force or work generation, which differs from many other motor tasks. Electromyography (EMG), an essential method for investigating motor function in general, has become critical to understanding the physiology of swallowing. In 1956, Doty and Bosma published a landmark paper using EMG to describe the motor pattern of a swallow. Since then, the specific methods of bi-polar indwelling electrodes have not significantly changed, but our understanding of muscle and ability to analyze EMG data has grown remarkably. Advances in imaging and quantitative analysis, largely derived from studies of fine motor control of the limbs and locomotion, are a boon to studies of swallowing and have advanced our understanding of neural control. EMG patterns are a direct readout of central motor control and are valuable for determining the evolution of swallowing, the normal physiology of swallowing, and the pathophysiology of dysphagia. The potential for increasing our knowledge of these aspects of swallowing is high, given current advances in EMG technique and analysis. Here, we briefly discuss the current state of our knowledge of the motor control of the swallow, review what we have learned in the past 70 years about the swallow, and end by highlighting how embracing novel technologies and techniques will enable us to further understand the neural control of this critical behavior.</p>","PeriodicalId":16563,"journal":{"name":"Journal of neurophysiology","volume":" ","pages":"337-346"},"PeriodicalIF":2.1,"publicationDate":"2025-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144475689","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effects of short-term dual action-simulation training combined with transcranial magnetic stimulation on corticospinal excitation and finger motor performance.","authors":"Kazumasa Konishi, Shinya Suzuki, Tsuyoshi Nakajima, Hideto Sano, Yosuke Kawano, Takehiko Moroi, Takumi Takeuchi, Masahito Takahashi, Satoshi Shibuya, Yohei Nagaoka, Naobumi Hosogane, Yukari Ohki","doi":"10.1152/jn.00483.2024","DOIUrl":"10.1152/jn.00483.2024","url":null,"abstract":"<p><p>Action-simulation training using action observation (AO), motor imagery (MI), or a combination of both (AOMI) may improve motor function in patients with neurological diseases. Although multiple sessions over several days or weeks are necessary to produce neurophysiological and behavioral effects in patients, the aftereffects of a single session are crucial for achieving long-term outcomes. This study aimed to investigate whether a single session of dual action-simulation (AOMI) training combined with transcranial magnetic stimulation (TMS) induces plastic changes in corticospinal excitation over time and affects motor performance in healthy individuals. The results demonstrated that 20 min of AOMI + TMS training produced a sustained increase in the amplitudes of motor-evoked potentials (MEPs), lasting for >30 min. In addition, interindividual variations in MEP amplitudes after AOMI + TMS could be predicted using MEP amplitude changes during training. The control experiments (MI + TMS, AO + TMS, and AOMI + TMS_sham) used to clarify which combination of the training components promoted increased MEP amplitudes, did not induce significant plastic changes. Furthermore, participants who underwent AOMI + TMS showed improved finger motor performance after training, whereas the control participants did not. These findings suggest that a single session of dual action-simulation training combined with TMS enhances corticospinal transmission over time and improves finger motor performance in healthy individuals.<b>NEW & NOTEWORTHY</b> This study provides evidence for the effectiveness of a novel action-simulation training protocol, combining action observation (AO) during motor imagery (MI) with transcranial magnetic stimulation (AOMI + TMS). The results showed that a single 20-min session of AOMI + TMS enhanced corticospinal excitation and improved finger-tapping performance in healthy individuals.</p>","PeriodicalId":16563,"journal":{"name":"Journal of neurophysiology","volume":" ","pages":"144-161"},"PeriodicalIF":2.1,"publicationDate":"2025-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144275080","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Anisotropic object-based shifts of attention arise from unequal influences of visual field meridians on neural attention gradients.","authors":"David Hughes, Adam J Barnas, Adam S Greenberg","doi":"10.1152/jn.00554.2024","DOIUrl":"https://doi.org/10.1152/jn.00554.2024","url":null,"abstract":"<p><p>Object-based attention prioritizes the processing of information appearing within a selected object. We previously showed an object-based shift direction anisotropy (SDA) whereby horizontal shifts are more efficient than vertical shifts (1, 2), an effect modulated by the visual field meridians (3). Our present aim was to understand how the functional brain mechanisms of attention give rise to the SDA. We hypothesized that the SDA arises from attentional resources being partitioned differently by horizontal and vertical meridians. To test this, we used fMRI of visual cortex while subjects shifted attention horizontally and vertically within a single, L-shaped object. An SDA was observed when targets crossed the visual field meridians, and the object vertex was positioned in the upper-left corner. However, no SDA was observed when the object vertex was positioned in the lower-right corner. Cue-related activations revealed that attention spreads throughout the vertical component of each object (even to locations where the target never appeared). Additionally, the vertical meridian seemed to impede the spread of attention for the upper-left object's horizontal component. However, for the lower-right object, the horizontal component showed a similar attentional modulation to its vertical component, commensurate with behavioral performance in response to that object. These results suggest the efficiency of horizontal shifts crossing the vertical meridian is enhanced by the support of attentional resources from both hemispheres. As such, we offer a refinement of how the visual field meridians may influence the spread of object-based attention via an anisotropic attention gradient.</p>","PeriodicalId":16563,"journal":{"name":"Journal of neurophysiology","volume":" ","pages":""},"PeriodicalIF":2.1,"publicationDate":"2025-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144540584","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Internal models in active self-motion estimation: role of inertial sensory cues.","authors":"Milou J L van Helvert, Luc P J Selen, Robert J van Beers, W Pieter Medendorp","doi":"10.1152/jn.00281.2024","DOIUrl":"10.1152/jn.00281.2024","url":null,"abstract":"<p><p>Self-motion estimation is thought to depend on sensory information and on sensory predictions derived from motor output. In driving, the inertial motion cues (vestibular and somatosensory cues) can in principle be predicted based on the steering motor commands if an accurate internal model of the steering dynamics is available. Here, we used a closed-loop steering experiment to examine whether participants can build such an internal model of the steering dynamics. Participants steered a motion platform on which they were seated to align their body with a memorized visual target in complete darkness. We varied the gain between the steering wheel angle and the velocity of the motion platform across trials in three different ways: unpredictable (white noise), moderately predictable (random walk), or highly predictable (constant gain). We examined whether participants took the across-trial predictability of the gain into account to control their steering (internal model hypothesis), or whether they simply integrated the inertial feedback over time to estimate their traveled distance (path integration hypothesis). Results show that participants relied on the gain of the previous trial more when it followed a random walk across trials than when it varied unpredictably across trials. Furthermore, on interleaved trials with a large jump in the gain, participants made fast corrective responses, irrespective of gain predictability, showing they also relied on inertial feedback next to predictions. These findings suggest that the brain can construct an internal model of the steering dynamics to predict the inertial sensory consequences in driving and self-motion estimation.<b>NEW & NOTEWORTHY</b> We used a closed-loop steering experiment to investigate whether an accurate internal model of the steering dynamics can be learned based on inertial sensory cues. Participants were shown to benefit from partially predictable steering dynamics; they took the across-trial predictability of the steering gain into account to control their steering. This suggests that they can build an internal model to anticipate the inertial reafference in driving and self-motion estimation.</p>","PeriodicalId":16563,"journal":{"name":"Journal of neurophysiology","volume":" ","pages":"171-182"},"PeriodicalIF":2.1,"publicationDate":"2025-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144293929","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}