Journal of Neurophysiology

JNP Micro Podcasts ”Four Questions”: Task-dependent negotiations of bimanual coordination

In this podcast Nick Kitchen and Jisung Yuk of Pennsylvania State University discuss the recently published manuscript “Bilateral arm movements are coordinated via task-dependent negotiations between independent and codependent control, but not by a “coupling” control policy.”

 

NEW & NOTEWORTHY Minimization of performance and control costs and efferent coupling between bilaterally homologous muscle groups have been separately hypothesized to describe patterns of bimanual coordination. Here, we address whether the mechanisms mediating independent and codependent control between limbs can be weighted for successful task performance. Using bilaterally asymmetric visuomotor gain perturbations, we show bimanual coordination can be characterized as a negotiation along a spectrum between extremes of independent and codependent control, but not efferent control coupling.

 

Article Citation:

Bilateral arm movements are coordinated via task-dependent negotiations between independent and codependent control, but not by a “coupling” control policy

Nick M. Kitchen, Jisung Yuk, Andrzej Przybyla, Robert A. Scheidt, and Robert L. Sainburg

Journal of Neurophysiology

 2023 130:3, 497-515

JNP Micro Podcasts ”Four Questions”: Otolith-ocular reflex after ototoxicity & vestibular implant

Margaret Chow and Celia Fernandez Brillet of Johns Hopkins School of Medicine discuss the recently published manuscript titled "Binocular 3-D otolith-ocular reflexes: responses of chinchillas to natural and prosthetic stimulation after ototoxic injury and vestibular implantation."

 

NEW & NOTEWORTHY Previous studies to expand the scope of prosthetic stimulation of the otolith end organs showed that selective stimulation of the utricle and saccule is possible. This article further defines those possibilities by characterizing a diseased animal model and subsequently studying its responses to electrical stimulation alone and in combination with mechanical motion. We show that we can partially restore responses to tilt and translation in animals with unilateral gentamicin ototoxic injury and contralateral surgical disruption.

 

Article Citation:

Binocular 3-D otolith-ocular reflexes: responses of chinchillas to natural and prosthetic stimulation after ototoxic injury and vestibular implantation

Margaret R. Chow, Celia Fernandez Brillet, Kristin N. Hageman, Dale C. Roberts, Andrianna I. Ayiotis, Razi M. Haque, and Charles C. Della Santina

Journal of Neurophysiology 2023 129:5, 1157-1176

JNP Micro Podcasts: Acetylcholine receptor and persistent current

In this paper first author Kelly H. Lee, and Alex Prosserman, an expert in the field discuss the recently published article titled “Cholinergic depolarization recruits a persistent Ca²⁺ current in Aplysia bag cell neurons.”

 

NEW & NOTEWORTHY Ionotropic acetylcholine receptors mediate brief synaptic communication, including in bag cell neurons of the sea snail Aplysia. However, this study demonstrates that cholinergic depolarization can open a voltage-gated persistent Ca²⁺ current, which extends the bag cell neuron response to acetylcholine. Bursting in these neuroendocrine cells results in hormone release and egg laying. Thus, this emphasizes the role of ionotropic signaling in reaching a depolarized level to engage Ca²⁺ influx and perpetuating the activity necessary for behavior.

 

Article Citation:

Cholinergic depolarization recruits a persistent Ca²⁺ current in Aplysia bag cell neurons

Kelly H. Lee, David E. Wassef, Eammon K. MacNeil, and Neil S. Magoski

Journal of Neurophysiology 2023 129:5, 1045-1060

JNP Micro Podcasts ”Four Questions”: Elijah Haynes, Jennifer Jakobi, and Jayne Kalmar

In this podcast Dr. Elijah Haynes and Dr. Jennifer Jakobi of the University of British Columbia Okanagan, and Dr. Jayne Kalmar of the Wilfrid Laurier University discuss the recently published Systematic Review titled “A systematic review of how cannabinoids affect motoneuron output.” This scoping review involved the synthesis of evidence from literature published before August 2022 about the effects of cannabinoids on quantifiable measures of motoneuron output. It contributes to understanding the effects of endocannabinoids on synaptic integration at the motoneuron and modulation of motor output.

 

Article Citation:

A systematic review of how cannabinoids affect motoneuron output

Elijah M. K. Haynes, Jayne M. Kalmar, Mathew Vis-Dunbar, Kathryn M. Crosby, Angitha Mriduraj, and Jennifer M. Jakobi

Journal of Neurophysiology

 2023 130:2, 247-263

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