Journal of Neurophysiology

JNP Podcasts: Improving localization and measurements of M-waves using high-density surface electromyography

In this episode, coauthor Ernesto Bedoy discusses their recently published research, "Improving Localization and Measurements of M-Waves Using High-Density Surface Electromyography." The study presents an innovative approach to enhancing the measurement of evoked potentials through high-density surface electromyography (HD-sEMG). By incorporating spatial filters and ultrasound imaging, the research significantly improves the precision and localization of evoked potentials, providing a more accurate method for assessing motor pathway integrity. These advancements hold promise for developing better tools to detect and treat neurological deficits, offering a significant contribution to the field of neurophysiological research.

 

Improving localization and measurements of M-waves using high-density surface electromyography

Ernesto H. Bedoy, Efrain A. Guirola Diaz, Ashley N. Dalrymple, Isaiah Levy, Thomas Hyatt, Darcy M. Griffin, George F. Wittenberg, and Douglas J. Weber

Journal of Neurophysiology 2025 133:1, 299-309

JNP Podcasts: Hypercapnia elicits changes in diaphragm neuromotor control

In this episode, coauthor Obaid U. Khurram discusses their recently published research, "Hypercapnia Impacts Neural Drive and Timing of Diaphragm Neuromotor Control." The study explores the complex neuromotor control of the diaphragm muscle (DIAm) under hypercapnic conditions, an area that has not been fully understood. Dr. Khurram explains how hypercapnia increases motor unit recruitment and discharge rates, indicating an enhanced respiratory drive. The research also reveals how hypercapnia affects the postinspiratory (descending) ramp of diaphragm EMG activity, shortening it to facilitate faster respiratory rates. Tune in for valuable insights into the physiological mechanisms of diaphragm function and adaptation in response to elevated carbon dioxide levels.

 

Hypercapnia impacts neural drive and timing of diaphragm neuromotor control

Obaid U. Khurram, Maximilian J. Kantor-Gerber, Carlos B. Mantilla, and Gary C. Sieck

Journal of Neurophysiology 2024 132:6, 1966-1976

JNP Micro Podcasts: Flexion reflexes during transspinal stimulation

In this episode, coauthors Maria Knikou and Abdullah M. Sayed Ahmad discuss their research on "Transspinal stimulation downregulates flexion reflex pathways during walking in healthy humans." The study investigates how transspinal stimulation over the thoracolumbar region affects reflex pathways during walking, revealing its ability to suppress the tibialis anterior flexion reflex at varying frequencies (15, 30, and 50 Hz).

Transspinal stimulation downregulates flexion reflex pathways during walking in healthy humans

Maria Knikou and Abdullah M. Sayed Ahmad

Journal of Neurophysiology 2025 133:2, 530-538

JNP Micro Podcasts: Impact of glucagon-like peptide-1 receptor agonists on axonal function in diabetic peripheral neuropathy

In this episode, coauthor Arun V. Krishnan highlights the article titled "Impact of glucagon-like peptide-1 receptor agonists on axonal function in diabetic peripheral neuropathy." Diabetic peripheral neuropathy is known to be relentlessly progressive and irreversible. Prospective studies in 24 participants with diabetic peripheral neuropathy (DPN) treated with glucagon-like peptide-1 receptor agonists (GLP-1RA) demonstrated improvements in clinical neuropathy scores, nerve conduction studies, and axonal excitability recordings. Analysis of axonal excitability recordings revealed the mechanism for GLP-1RA improvement in DPN were changed consistent with improvements in Na⁺/K⁺–ATPase pump function, and this was supported by mathematical modeling.

 

Impact of glucagon-like peptide-1 receptor agonists on axonal function in diabetic peripheral neuropathy

Roshan Dhanapalaratnam, Tushar Issar, Ann M. Poynten, Kerry-Lee Milner, Natalie C. G. Kwai, and Arun V. Krishnan

Journal of Neurophysiology 2025 133:1, 14-21

JNP Micro Podcasts: Uncovering Balance Control from Foot Force

Join coauthors Rika Dimitrova and Kaymie Shiozawa in this podcast where they dive deep into their research on human balance control. In this episode, they explore the insights of three papers: "Frequency-domain patterns in foot-force line-of-action: an emergent property of standing balance control," "Human foot force suggests different balance control between younger and older adults," and "Human foot force informs balance control strategies when standing on a narrow beam."

Their work uncovers a novel, closed-form analytical result that links the frequency-domain patterns of foot force to the body’s neuromotor control during quiet standing. The podcast delves into the complexities of balance control in different age groups, demonstrating how older adults adapt their balance strategies to compensate for muscle weakness, relying more on neural feedback. With a focus on foot-ground force interactions, the duo breaks down how these findings can provide a new balance assessment tool, highlighting its significance in both research and real-world applications.

Additionally, Dr. Sugimoto-Dimitrova and Dr. Shiozawa discuss the challenges of maintaining balance in more demanding conditions—such as standing on a narrow beam—and explore how biomechanics and neural control work together to stabilize the body.

 

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Frequency-domain patterns in foot-force line-of-action: an emergent property of standing balance control

Rika Sugimoto-Dimitrova, Kaymie Shiozawa, Kreg G. Gruben, and Neville Hogan

Journal of Neurophysiology 2024 132:5, 1445-1456

 

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Human foot force suggests different balance control between younger and older adults

Kaymie Shiozawa, Rika Sugimoto-Dimitrova, Kreg G. Gruben, and Neville Hogan

Journal of Neurophysiology 2024 132:5, 1457-1469

 

Human foot force informs balance control strategies when standing on a narrow beam

Kaymie Shiozawa, Marta Russo, Jongwoo Lee, Neville Hogan, and Dagmar Sternad

Journal of Neurophysiology 2024 132:4, 1302-1314

 

JNP Micro Podcasts: Exploring Amiloride's Impact on Baroreflex Sensitivity and Blood Pressure Variability in Healthy Young Adults

In this episode of the Journal of Neurophysiology's Podcast Series, coauthor Igor A. Fernandes discusses the research titled "Does a Single Oral Administration of Amiloride Affect Spontaneous Arterial Baroreflex Sensitivity and Blood Pressure Variability in Healthy Young Adults?" This study builds on preclinical models that suggest amiloride (AMD), a nonselective antagonist of acid-sensing ion channels (ASICs), may impair baroreflex sensitivity and disrupt blood pressure regulation. Igor explains how the research team translated these findings to human subjects, investigating the effects of acute oral ingestion of AMD on blood pressure variability and baroreflex sensitivity in healthy young adults. Surprisingly, the study found that, contrary to preclinical evidence, AMD did not impair spontaneous arterial baroreflex sensitivity or blood pressure variability in humans. Tune in to explore the implications of these findings for understanding blood pressure regulation and the role of ASICs in humans.

 

Does a single oral administration of amiloride affect spontaneous arterial baroreflex sensitivity and blood pressure variability in healthy young adults?

Igor A. Fernandes, Jon Stavres, Takuto Hamaoka, Qudus A. Ojikutu, Jeann L. Sabino-Carvalho, Lauro C. Vianna, J. Carter Luck, Cheryl Blaha, Aimee E. Cauffman, Paul C. Dalton, Michael D. Herr, Victor Ruiz-Velasco, Zyad J. Carr, Piotr K. Janicki, and Jian Cui

Journal of Neurophysiology 2024 132:3, 922-928

 

JNP Micro Podcasts: Enhancing Balance: How Ballet Practice Boosts Neuromuscular and Biomechanical Responses to Slips in Older Adults

In this episode of the Journal of Neurophysiology's Podcast Series, coauthor Caroline Simpkins discusses the research titled "Ballet Practice Improves Neuromuscular and Biomechanical Responses to an Unexpected Standing-Slip in Older Adults." This study is the first to examine how older ballet dancers respond to an unexpected external slip while standing. Caroline shares fascinating findings that reveal how older ballet dancers have a reduced fall risk compared to their nondancer peers. This improved stability is attributed to quicker neuromuscular reactions, allowing dancers to execute a more effective recovery step and maintain greater balance against backward falls. Tune in to learn how ballet practice can enhance balance and reduce fall risk in older adults.

 

Ballet practice improves neuromuscular and biomechanical responses to an unexpected standing-slip in older adults

Caroline Simpkins and Feng Yang

Journal of Neurophysiology 2024 132:4, 1115-1125

JNP Micro Podcasts: Reflex interactions on action potential subpopulations

In this episode of the Journal of Neurophysiology's Podcast Series, coauthor Natasha G. Boyes delves into her recently published research, "Interaction of Simultaneous Hypoxia and Baroreflex Loading on Control of Sympathetic Action Potential Subpopulations." This study explores the complex interaction between baroreflex loading and peripheral chemoreflex activation in regulating the sympathetic nervous system. Dr. Boyes explains how chemoreflex activation buffers baroreflex-induced reductions in sympathetic activity and reveals that baroreflex loading significantly alters sympathetic action potential clusters, even in the presence of chemoreflex signals. Tune in to hear how this research provides new insights into the dominant role of the arterial baroreflex in controlling medium-sized sympathetic neurons amidst competing stressors.

 

Interaction of simultaneous hypoxia and baroreflex loading on control of sympathetic action potential subpopulations

Natasha G. Boyes, Stephen A. Klassen, Sarah E. Baker, Wayne T. Nicholson, Michael J. Joyner, J. Kevin Shoemaker, and Jacqueline K. Limberg

Journal of Neurophysiology 2024 132:3, 1087-1097

JNP Micro Podcasts: Bidirectional Generative Adversarial Representation Learning for Natural Stimulus Synthesis

In this episode, coauthors Andriy S. Kozlov, Johnny Reilly, and John D. Goodwin discuss their recently published research titled "Bidirectional Generative Adversarial Representation Learning for Natural Stimulus Synthesis." The authors introduce a groundbreaking artificial neural network that generates animal vocalization waveforms and interpolates between them to create new, realistic vocalizations. The team shares how their synthetic stimuli drive auditory cortical neurons in mice just as effectively as natural vocalizations, producing receptive field features with equal predictive power. Tune in as Andriy, Johnny, and John explain the significance of their findings and the potential implications of this innovative technology for sensory neuroscience.

 

Bidirectional generative adversarial representation learning for natural stimulus synthesis

Johnny Reilly, John D. Goodwin, Sihao Lu, and Andriy S. Kozlov

Journal of Neurophysiology 2024 132:4, 1156-1169

JNP Micro Podcasts: Locomotor Learning in Chronic Hemiparetic Stroke

In this episode, coauthor Jonathan M. Wood provides an in-depth overview of the recently published research titled "Explicit and Implicit Locomotor Learning in Individuals with Chronic Hemiparetic Stroke." The study explores how motor learning, which involves both implicit and explicit processes, is affected in individuals with chronic hemiparetic stroke. These two types of learning, which typically work together in daily life and rehabilitation, may be disrupted after a stroke. Using a locomotor task designed to isolate contributions from both processes, alongside computational modeling, the research reveals that chronic stroke leads to deficits in both explicit and implicit locomotor learning. Join Jonathan as he discusses the findings and their implications for understanding motor recovery post-stroke.

 

Explicit and implicit locomotor learning in individuals with chronic hemiparetic stroke

Jonathan M. Wood, Elizabeth Thompson, Henry Wright, Liam Festa, Susanne M. Morton, Darcy S. Reisman, and Hyosub E. Kim

Journal of Neurophysiology 2024 132:4, 1172-1182