» Articles » PMID: 29479302

Influence of Brain Stem on Axial and Hindlimb Spinal Locomotor Rhythm Generating Circuits of the Neonatal Mouse

Overview
Journal Front Neurosci
Date 2018 Feb 27
PMID 29479302
Citations 4
Authors
Affiliations
Soon will be listed here.
Abstract

The trunk plays a pivotal role in limbed locomotion. Yet, little is known about how the brain stem controls trunk activity during walking. In this study, we assessed the spatiotemporal activity patterns of axial and hindlimb motoneurons (MNs) during drug-induced fictive locomotor-like activity (LLA) in an isolated brain stem-spinal cord preparation of the neonatal mouse. We also evaluated the extent to which these activity patterns are affected by removal of brain stem. Recordings were made in the segments T7, L2, and L5 using calcium imaging from individual axial MNs in the medial motor column (MMC) and hindlimb MNs in lateral motor column (LMC). The MN activities were analyzed during both the rhythmic and the tonic components of LLA, the tonic component being used as a readout of generalized increase in excitability in spinal locomotor networks. The most salient effect of brain stem removal was an increase in locomotor rhythm frequency and a concomitant reduction in burst durations in both MMC and LMC MNs. The lack of effect on the tonic component of LLA indicated specificity of action during the rhythmic component. Cooling-induced silencing of the brain stem reproduced the increase in rhythm frequency and accompanying decrease in burst durations in L2 MMC and LMC, suggesting a dependency on brain stem neuron activity. The work supports the idea that the brain stem locomotor circuits are operational already at birth and further suggests an important role in modulating trunk activity. The brain stem may influence the axial and hindlimb spinal locomotor rhythm generating circuits by extending their range of operation. This may represent a critical step of locomotor development when learning how to walk in different conditions and environments is a major endeavor.

Citing Articles

Effect of galvanic vestibular stimulation applied at the onset of stance on muscular activity and gait cycle duration in healthy individuals.

Abbariki F, Mikhail Y, Hamadjida A, Charron J, Mac-Thiong J, Barthelemy D Front Neural Circuits. 2023; 16:1065647.

PMID: 36845254 PMC: 9946991. DOI: 10.3389/fncir.2022.1065647.


Crossed activation of thoracic trunk motoneurons by medullary reticulospinal neurons.

LaPallo B, Giorgi A, Perreault M J Neurophysiol. 2019; 122(6):2601-2613.

PMID: 31664872 PMC: 6957368. DOI: 10.1152/jn.00194.2019.


Synchronization of Non-linear Oscillators for Neurobiologically Inspired Control on a Bionic Parallel Waist of Legged Robot.

Zhu Y, Zhou S, Gao D, Liu Q Front Neurorobot. 2019; 13:59.

PMID: 31427942 PMC: 6687854. DOI: 10.3389/fnbot.2019.00059.


The rhythm section: An update on spinal interneurons setting the beat for mammalian locomotion.

Dougherty K, Ha N Curr Opin Physiol. 2019; 8:84-93.

PMID: 31179403 PMC: 6550992. DOI: 10.1016/j.cophys.2019.01.004.

References
1.
Hinckley C, Alaynick W, Gallarda B, Hayashi M, Hilde K, Driscoll S . Spinal Locomotor Circuits Develop Using Hierarchical Rules Based on Motorneuron Position and Identity. Neuron. 2015; 87(5):1008-21. PMC: 4592696. DOI: 10.1016/j.neuron.2015.08.005. View

2.
Kishore S, Bagnall M, McLean D . Systematic shifts in the balance of excitation and inhibition coordinate the activity of axial motor pools at different speeds of locomotion. J Neurosci. 2014; 34(42):14046-54. PMC: 4198544. DOI: 10.1523/JNEUROSCI.0514-14.2014. View

3.
Beyeler A, Metais C, Combes D, Simmers J, Le Ray D . Metamorphosis-induced changes in the coupling of spinal thoraco-lumbar motor outputs during swimming in Xenopus laevis. J Neurophysiol. 2008; 100(3):1372-83. DOI: 10.1152/jn.00023.2008. View

4.
Wada N, Kanda K . Trunk movements and EMG activity in the cat: level versus upslope walking. Prog Brain Res. 2003; 143:175-81. DOI: 10.1016/s0079-6123(03)43017-3. View

5.
Jiang Z, Carlin K, Brownstone R . An in vitro functionally mature mouse spinal cord preparation for the study of spinal motor networks. Brain Res. 1999; 816(2):493-9. DOI: 10.1016/s0006-8993(98)01199-8. View