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.

Journal of Neurophysiology 2024 131:2, 417-434

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

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:

Journal of Neurophysiology 2024 131:5, 807-814

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.

Journal of Neurophysiology 2023 130:6, 1578-1587

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:

Journal of Neurophysiology 2024 131:1, 16-27

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:

Journal of Neurophysiology 2023 130:5, 1309-1320

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:

Journal of Neurophysiology 2023 130:5, 1303-1308

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

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