Journal of Neurophysiology

JNP Micro Podcast: Switching Neuron Contributions to Second Network

In this episode, coauthor Savanna-Rae H. Fahoum dives into her recent research, shedding light on "Switching Neuron Contributions to Second Network Activity" and "Neuropeptide Modulation of Bidirectional Internetwork Synapses." Collaborating with Dawn M. Blitz, they utilize rhythmic neuronal networks in crabs as a model to explore the complex interactions between these networks and neurons capable of switching their network participation. Their findings reveal that when a neuron transitions into dual-network activity, only the second network influences its activity within that context. Furthermore, while the switching neuron can effectively coordinate second network neurons and regulate their activity levels, it's not always indispensable, suggesting a nuanced regulation of switching neurons that challenges the traditional view of them merely as followers in additional networks.

 

Switching neuron contributions to second network activity

Savanna-Rae H. Fahoum and Dawn M. Blitz

Journal of Neurophysiology 2024 131:2, 417-434

 

https://doi.org/10.1152/jn.00149.2024

JNP Micro Podcast: Pontine Reticular Nuclei Scales with Handgrip Force

In this episode, Justin W. Andrushko discusses the recently published research titled "Activity in the pontine reticular nuclei scales with handgrip force in humans." In this study, the authors used a task-based functional magnetic resonance imaging (fMRI) paradigm to show that activity in the pontine reticular nuclei scales linearly with increasing force during a handgrip task. These findings directly support recently proposed hypotheses that the reticulospinal tract may play an important role in modulating force production in humans.

 

Article Citation:

Activity in the pontine reticular nuclei scales with handgrip force in humans

Tyler L. Danielson, Layla A. Gould, Jason M. DeFreitas, Rob J. MacLennan, Chelsea Ekstrand, Ron Borowsky, Jonathan P. Farthing, and Justin W. Andrushko

Journal of Neurophysiology 2024 131:5, 807-814

JNP Micro Podcasts: Inhibitory Synaptic Transmission in the Kölliker-Fuse of Rett Syndrome mice

In this episode of JNP's micro podcasts, Jessica R. Whitaker-Fornek of the University of Michigan Medical School discusses the recently published research titled "Inhibitory synaptic transmission is impaired in the Kölliker-Fuse of male, but not female, Rett syndrome mice." 

NEW & NOTEWORTHY Kölliker-Fuse (KF) neurons in acute brain slices from male Rett syndrome (RTT) mice receive reduced inhibitory synaptic inputs compared with wild-type littermates. In female RTT mice, inhibitory transmission was not different in KF neurons compared with controls. The results from this study show that sex-specific alterations in synaptic transmission occur in the KF of RTT mice.

 

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Inhibitory synaptic transmission is impaired in the Kölliker-Fuse of male, but not female, Rett syndrome mice

Jessica R. Whitaker-Fornek, Paul M. Jenkins, and Erica S. Levitt

Journal of Neurophysiology 2023 130:6, 1578-1587

JNP Micro Podcasts: Game-based Rotational Vestibulo-Ocular Reflex Adaptation

In this episode Mark F. Walker of Case Western Reserve University, discusses the recently published research titled "Short-term learning of the vestibulo-ocular reflex induced by a custom interactive computer game."

 

NEW & NOTEWORTHY This study demonstrates the feasibility and efficacy of a customized computer game to induce motor learning in the high-frequency rotational vestibulo-ocular reflex. It provides a physiological basis for the deployment of this technology to clinical vestibular rehabilitation.

 

Article Citation:

Short-term learning of the vestibulo-ocular reflex induced by a custom interactive computer game

Qi Li, Honglu Xu, Weicong Chen, Andrew Su, Michael J. Fu, and Mark F. Walker

Journal of Neurophysiology 2024 131:1, 16-27

 

JNP Micro Podcasts: Visual Strategy and Force-Steadiness in Older Adults

In this podcast Brittany Heintz Walters of Seattle University discusses the recently published research titled "Visual feedback and declines in attention are associated with altered visual strategy during a force-steadiness task in older adults." 

 

NEW & NOTEWORTHY This study contributes novel findings of age-related changes in visual strategy and associations with attentional deficits during hand motor tasks. Older adults used fewer saccades than young adults and with higher versus lower gain visual feedback during a force-steadiness task. A subset of older adults used an altered visual strategy when allocating attention across multiple tasks. Given that this subset demonstrated attentional deficits, the altered visual strategy could serve to indicate motor and/or cognitive impairments.

 

Article Citation:

Visual feedback and declines in attention are associated with altered visual strategy during a force-steadiness task in older adults

Brittany Heintz Walters, Wendy E. Huddleston, Kristian O’Connor, Jinsung Wang, Marie Hoeger Bement, and Kevin G. Keenan

Journal of Neurophysiology 2023 130:5, 1309-1320

JNP Micro Podcasts: Aging and Subcortical Gray Matter Volume

In this podcast Dr. Peka Christova of The Neuroimaging Research Group, Brain Sciences Center discusses the recently published Short Report titled "Changes of gray matter volumes of subcortical regions across the lifespan: a Human Connectome Project study."

NEW & NOTEWORTHY Christova et al. report mixed effects of age on subcortical grey matter volume (GMV) during lifespan (n = 2458, 5-90 yr old, 1113 male, 1345 female). Striatal and cerebellar GMVs decreased linearly with age, more steeply in males. In contrast, GMVs of the amygdala, pallidum, thalamus, ventral diencephalon, and brainstem changed in a quadratic fashion, increasing first and decreasing afterward, with males peaking earlier than females in all regions but the brainstem where they peaked at nearly the same time.

Article Citation:

Changes of gray matter volumes of subcortical regions across the lifespan: a Human Connectome Project study

Peka Christova and Apostolos P. Georgopoulos

Journal of Neurophysiology 2023 130:5, 1303-1308

JNP Micro Podcasts: Modulation of corticospinal excitability during vibration

In this episode,  Lydiane Lauzier of Université du Québec à Chicoutimi discusses the recently published article “Variation of corticospinal excitability during kinesthetic illusion induced by musculotendinous vibration.”

 

New and Noteworthy:

The modulation of corticospinal excitability when perceiving a vibration (VIB)-induced kinesthetic illusion evolves dynamically over time. This modulation might be linked to the delayed occurrence and progressive increase in strength of the illusory perception in the first seconds after VIB start. Different spinal/cortical mechanisms could be at play during VIB, depending on the tested muscle, presence/absence of an illusion, and the specific timing at which corticospinal drive is tested pre/post VIB.

 

Article Citation:

Variation of corticospinal excitability during kinesthetic illusion induced by musculotendinous vibration

Lydiane Lauzier, Marie-Pier Perron, Laurence Munger, Émilie Bouchard, Jacques Abboud, François Nougarou, and Louis-David Beaulieu

Journal of Neurophysiology 2023 130:5, 1118-1125

JNP Micro Podcasts ”Four Questions”: Robust Aggregate Code of Competing Sounds in Auditory Cortex

In this podcast, author Jian Carlo Nocon (Boston University) discusses the recently published research titled "A robust and compact population code for competing sounds in auditory cortex." 

 

NEW & NOTEWORTHY 

Little is known about how populations of neurons within cortical circuits encode sensory stimuli in the presence of competing stimuli at other spatial locations. Here, the authors investigate this problem in auditory cortex using a recently proposed information-theoretic approach. They found a small subset of neurons nearly maximizes information about target sounds in the presence of competing maskers, approaching information levels for isolated stimuli, and provides a noise-robust code for sounds in a complex auditory scene.

 

Article Citation:

A robust and compact population code for competing sounds in auditory cortex

Jian Carlo Nocon, Jake Witter, Howard Gritton, Xue Han, Conor Houghton, and Kamal Sen

Journal of Neurophysiology 2023 130:3, 775-787

JNP Micro Podcasts ”Four Questions”: Essential Tremor accentuates upper limb coherence patterns

In this podcast coauthor Daniel Free of Brigham Young University talks about the recently published article titled “Essential tremor accentuates the pattern of tremor-band coherence between upper limb muscles.”

 

NEW & NOTEWORTHY This research characterized the relationships in tremor-band activity between the 15 major superficial upper limb muscles of persons with essential tremor by quantifying the proportion of shared activity (coherence) in the tremor band and by characterizing phase differences between these muscles during various tasks. From the authors observations, they conclude that tremor enhances the coherence between muscle pairs throughout the upper limb in a pattern that reflects functional relationship between them.

 

Article Citation:

Essential tremor accentuates the pattern of tremor-band coherence between upper limb muscles

Daniel B. Free, Ian Syndergaard, Adam C. Pigg, Silvia Muceli, Johanna Thompson-Westra, Karin Mente, Carine W. Maurer, Dietrich Haubenberger, Mark Hallett, Dario Farina, and Steven K. Charles

Journal of Neurophysiology 2023 129:3, 524-540

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