Journal of Neurophysiology

JNP Micro Podcasts ”Four Questions”: Alexander M. Zero

In this podcast co lead author Alexander M. Zero of The University of Western Ontario discusses the recently published research titled "Motor unit firing rates in young and very old adult males during an isokinetic fatiguing task and short-term recovery in the anconeus muscle."

 

NEW & NOTEWORTHY Maximal motor unit firing rates were recorded during an isokinetic fatiguing protocol and short-term recovery in young and very old adult males. Prior studies were limited to isometric fatiguing tasks. Despite the old being ∼37% weaker and less fatigable, anconeus rates during elbow extension declined with fatigue and recovered similarly to young males. Therefore, it is unlikely that greater fatigue resistance of very old males during isokinetic contractions is related to differences in motor unit rates.

 

Article Citation:

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Motor unit firing rates in young and very old adult males during an isokinetic fatiguing task and short-term recovery in the anconeus muscle

Alexander M. Zero, Eric A. Kirk, Kevin J. Gilmore, and Charles L. Rice

Journal of Neurophysiology 2023 130:1, 179-188

JNP Micro Podcasts ”Four Questions”: Robert Kass

In this podcast Robert E. Kass of Carnegie Mellon University discusses the recently published review article titled "Identification of interacting neural populations: methods and statistical considerations." 

 

Abstract: As improved recording technologies have created new opportunities for neurophysiological investigation, emphasis has shifted from individual neurons to multiple populations that form circuits, and it has become important to provide evidence of cross-population coordinated activity. We review various methods for doing so, placing them in six major categories while avoiding technical descriptions and instead focusing on high-level motivations and concerns. Our aim is to indicate what the methods can achieve and the circumstances under which they are likely to succeed. Toward this end, we include a discussion of four cross-cutting issues: the definition of neural populations, trial-to-trial variability and Poisson-like noise, time-varying dynamics, and causality.

 

Article Citation:

Identification of interacting neural populations: methods and statistical considerations

Robert E. Kass, Heejong Bong, Motolani Olarinre, Qi Xin, and Konrad N. Urban

Journal of Neurophysiology 2023 130:3, 475-496

JNP Micro Podcasts ”Four Questions”: Xiaoxuan Ren, Ilhan Bok, Adam Vareberg, and Aviad Hai

In this podcast Xiaoxuan Ren, Ilhan Bok, Adam Vareberg, and Prof. Aviad Hai of the University of Wisconsin-Madison discuss their recently published Innovative Methodology titled "Stimulation-mediated reverse engineering of silent neural networks."

 

NEW & NOTEWORTHY We introduce a new concept for reverse engineering silent neuronal networks using a supervised learning algorithm combined with stimulation. We quantify the performance of the algorithm and the precision of deriving synaptic weights in inhibitory and excitatory subpopulations. We then show that stimulation enables deciphering connectivity of heterogeneous circuits fed with real electrode array recordings, which could extend in the future to deciphering connectivity in broad biological and artificial neural networks.

 

Article Citation: 

Stimulation-mediated reverse engineering of silent neural networks

Xiaoxuan Ren, Ilhan Bok, Adam Vareberg, and Aviad Hai

Journal of Neurophysiology 2023 129:6, 1505-1514

JNP Micro Podcasts ”Four Questions”: Apostolos P. Georgopoulos

In our latest podcast Prof. Apostolos P. Georgopoulos discusses recently published Short Report titled "Changes of cortical gray matter volume during development: a Human Connectome Project study." 

 

NEW & NOTEWORTHY We report mixed effects of age on cortical gray matter volume during development in a large sample of 649 participants studied in an identical manner (6–21 yr old, 299 males, 350 females). Volumes of 30/35 cortical areas decreased with age, temporal pole increased, and pericalcarine and hippocampal cortex (hippocampus, parahippocampal, and entorhinal) did not change. These findings were very similar in both sexes and provide a solid base for assessing region-specific cortical changes during development.

 

Article Citation: 

Changes of cortical gray matter volume during development: a Human Connectome Project study

Peka Christova and Apostolos P. Georgopoulos

Journal of Neurophysiology 2023 130:1, 117-122

JNP Micro Podcasts ”Four Questions”: Todd P. Silverstein

In this podcast Dr. Todd Silverstein of Willamette University discusses his recently published review titled "Lee’s “Transmembrane Electrostatically-Localized Proton” model does NOT offer a better understanding of neuronal transmembrane potentials." 

 

NEW & NOTEWORTHY In this manuscript I critique a 2020 J. Neurophysiol. paper by James W. Lee. His TELP hypothesis 1) mispredicts the resting neuron’s excess of external chloride; 2) predicts the preponderance of surface H⁺ over Na⁺ using ΔG° rather than ΔG; 3) mispredicts the dependence of the neuronal resting potential on external [Na⁺], [K⁺], and [Cl⁻]; 4) neither cites experimental results nor proposes experiments to test his hypothesis; and 5) presents a problematic characterization of the purpose of myelin.

 

Article Citation:

Lee’s “Transmembrane Electrostatically-Localized Proton” model does NOT offer a better understanding of neuronal transmembrane potentials

Todd P. Silverstein

Journal of Neurophysiology 2023 130:1, 123-127

JNP Micro Podcasts ”Four Questions”: Mitchell Adrien St. Pierre and Minoru Shinohara

In this micro podcast Mitchell Adrien St. Pierre and Minoru Shinohara of the Georgia Institute of Technology discuss their recently published manuscript "Transcutaneous vagus nerve stimulation at nonspecific timings during training can compromise motor adaptation in healthy humans." 

 

NEW & NOTEWORTHY Adding vagus nerve stimulation via implanted electrodes during motor training can facilitate motor recovery in disabled animals and humans. No study examined the effect of transcutaneous vagus nerve stimulation (tVNS) during training on neuromotor adaptation in healthy humans. We have found that adding tVNS at nonspecific timings during motor skill training can compromise motor adaptation but not transfer in healthy humans.

 

Article Citation:

Transcutaneous vagus nerve stimulation at nonspecific timings during training can compromise motor adaptation in healthy humans

Mitchell Adrien St. Pierre and Minoru Shinohara

Journal of Neurophysiology 2023 130:1, 212-223

JNP Micro Podcasts ”Four Questions”: Tea Lulic-Kuryllo and David B. Lipps

In this micro podcast Dr. Tea Lulic-Kuryllo and Dr. David Lipps of the University of Michigan discuss their recently published research titled "Assessing shoulder muscle stretch reflexes following breast cancer treatment and postmastectomy breast reconstruction."

 

NEW & NOTEWORTHY Shoulder muscle stretch reflexes may be impacted following postmastectomy breast reconstruction and chemoradiation. Here, we examined short- and long-latency shoulder muscle stretch reflexes in two experiments following common breast reconstruction procedures and chemoradiation. We show impairments in pectoralis major stretch reflexes following postmastectomy breast reconstruction and pectoralis major and deltoid muscle stretch reflexes following chemoradiation. These findings indicate that breast cancer treatments alter the regulation of shoulder muscle stretch reflexes.

 

Citation

Assessing shoulder muscle stretch reflexes following breast cancer treatment and postmastectomy breast reconstruction

Tea Lulic-Kuryllo, Joshua M. Leonardis, Adeyiza O. Momoh, and David B. Lipps

Journal of Neurophysiology 2023 129:4, 914-926

JNP Micro Podcasts ”Four Questions”: Aiko Thompson and Alan Phipps

In this podcast Aiko Thompson and Alan Phipps of the Medical University of South Carolina talk about their recently published manuscript titled "Altered cutaneous reflexes to non-noxious stimuli in the triceps surae of people with chronic incomplete spinal cord injury"

 

NEW & NOTEWORTHY This study examined modulation of the triceps surae cutaneous reflexes during standing and walking and the relationship between cutaneous and H-reflexes in people with chronic incomplete spinal cord injury (SCI). In people with SCI, the normal task-dependent, nerve-specific modulation of triceps cutaneous reflexes was missing. Cutaneous and H-reflexes were not correlated. Together with other spinal reflexes, cutaneous reflexes may serve as important biomarkers for the state of spinal interneuronal pathways.

 

Citation

Altered cutaneous reflexes to non-noxious stimuli in the triceps surae of people with chronic incomplete spinal cord injury

Alan M. Phipps and Aiko K. Thompson

Journal of Neurophysiology 2023 129:3, 513-523

JNP Micro Podcasts ”Four Questions”: Johannes Keyser, and Leonie Oostwoud Wijdenes

In this podcast Johannes Keyser (Justus Liebig University Giessen) and Leonie Oostwoud Wijdenes (Radboud University Nijmegen) talk about their recently published research "Late integration of vision and proprioception during perturbed reaches." 

 

NEW & NOTEWORTHY Both visual and proprioceptive signals provide information about arm state during reaching. By perturbing the perceived, but not the actual, position of the hand in both modalities using visual disturbances and muscle vibration, we examined multimodal integration and state estimation during reaching. Our results suggest that the early reach corrections are based on separate state estimates from the two sensory modalities and only later are based on a combined state estimate.

 

Citation:

Late integration of vision and proprioception during perturbed reaches

Johannes Keyser, W. Pieter Medendorp, Leonie Oostwoud Wijdenes, and Luc P. J. Selen

Journal of Neurophysiology 2023 129:6, 1282-1292

JNP Micro Podcasts ”Four Questions”: Adalee J. Lube, and Bruce A. Carlson

Adalee J. Lube and Bruce Carlson of Washington University in St. Louis discuss their recently published manuscript "Spike timing-dependent plasticity alters electrosensory neuron synaptic strength in vitro but does not consistently predict changes in sensory tuning in vivo" in our newest micro podcast series. 

 

NEW & NOTEWORTHY We replicated behaviorally relevant temporal patterns of synaptic activity in vitro and used the same patterns during sensory stimulation in vivo. There was a Hebbian spike timing-dependent plasticity (STDP) pattern in vitro, but sensory responses in vivo did not shift according to STDP predictions. Analysis suggests that this disparity is influenced by differences in polysynaptic activity, including inhibitory interneurons. These results suggest that STDP rules at synapses in vitro do not necessarily apply to circuits in vivo.

 

Citation:

Spike timing-dependent plasticity alters electrosensory neuron synaptic strength in vitro but does not consistently predict changes in sensory tuning in vivo

Adalee J. Lube, Xiaofeng Ma, and Bruce A. Carlson

Journal of Neurophysiology 2023 129:5, 1127-1144