Projection of cortical beta band oscillations to a motor neuron pool across the full range of recruitment
File(s)
Published version
Author(s)
Abbagnano, Emanuele
Pascual-Valdunciel, Alejandro
Zicher, Blanka
Ibanez, Jaime
Farina, Dario
Type
Journal Article
Abstract
Cortical beta band oscillations (13–30 Hz) are associated with sensorimotor control, but their precise role remains unclear. Evidence suggests that for low-threshold motor neurons (MNs), these oscillations are conveyed to muscles via the fastest corticospinal fibers. However, their transmission to MNs of different sizes may vary due to differences in the relative strength of corticospinal and reticulospinal projections across the MN pool. Consequently, it remains uncertain whether corticospinal beta transmission follows similar pathways and maintains consistent strength across the entire MN pool. To investigate this, we examined beta activity in MNs innervating the tibialis anterior muscle across the full range of recruitment thresholds in a study involving 12 participants of both sexes. We characterized beta activity at both the cortical and motor unit (MU) levels, while participants performed contractions from mild to submaximal levels. Corticomuscular coherence remained unchanged across contraction forces after normalizing for the net MU spike rate, suggesting that beta oscillations are transmitted with similar strength to MNs, regardless of size. To further explore beta transmission, we estimated corticospinal delays using the cumulant density function, identifying peak correlations between cortical and muscular activity. Once compensated for variable peripheral axonal propagation delay across MNs, the corticospinal delay remained stable, and its value (∼14 ms) indicated projections through the fastest corticospinal fibers for all MNs. These findings demonstrate that corticospinal beta band transmission is determined by the fastest pathway connecting in the corticospinal tract, projecting similarly across the entire MN pool.
Date Issued
2025-07-30
Date Acceptance
2025-07-03
Citation
Journal of Neuroscience, 2025, 45 (31)
ISSN
0270-6474
Publisher
Society for Neuroscience
Journal / Book Title
Journal of Neuroscience
Volume
45
Issue
31
Copyright Statement
© 2025 Abbagnano et al. This is an open-access article distributed under the terms of the Creative Commons Attribution 4.0 International license, which permits unrestricted use, distribution and reproduction in any medium provided that the original work is properly attributed.
License URL
Identifier
https://www.ncbi.nlm.nih.gov/pubmed/40634126
PII: JNEUROSCI.0453-25.2025
Subjects
AMPLITUDE CANCELLATION
beta oscillations
COMMON SYNAPTIC INPUT
COMPONENTS
CORTEX
corticomuscular coherence
CORTICOMUSCULAR COHERENCE
corticospinal transmission
cumulant density analysis
ELECTROMYOGRAM
Life Sciences & Biomedicine
motor neurons
motor unit recruitment
MUSCLES
Neurosciences
Neurosciences & Neurology
POTENTIALS
Science & Technology
SYNCHRONIZATION
TASK
Publication Status
Published
Coverage Spatial
United States
Article Number
e0453252025
Date Publish Online
2025-07-09