ijms-logo

Journal Browser

Journal Browser

Special Issue "Neuronal Control of Locomotion"

A special issue of International Journal of Molecular Sciences (ISSN 1422-0067). This special issue belongs to the section "Molecular Neurobiology".

Deadline for manuscript submissions: closed (30 April 2021).

Special Issue Editor

Assoc. Prof. Turgay Akay
E-Mail
Guest Editor
Brain Repair Center, Atlantic Mobility Action Project, Department of Medical Neuroscience, Dalhousie University, Halifax, NS, Canada
Interests: Motor Control; Neuroscience; Locomotion; Central Pattern Generation; Proprioception; Reflexes

Special Issue Information

Dear Colleagues,

One of the main areas of Neuroscience research is understanding how the nervous system generates and controls movement. Research that aims to understand locomotion, defined as the movement of an organism from one place to another, has been one of the main areas contributing to this understanding. During locomotion, patterned and rhythmic contractions of multiple muscles underlie the coordinated movement of the body or limbs to provide posture and propulsion. These patterned contractions of muscles are controlled by the activities of motor neuron pools located within the central nervous system (CNS). It is generally accepted that at least some aspects of this patterned motor neuron activation are controlled by the action of a pre-motor network of interneurons within CNS, the central pattern generator (CPG). Moreover, the activity of the CPG is constantly modified by the sensory feedback from the periphery that provides the CPG with the information regarding the terrain, the body, and equilibrium. Despite the large volume of information that we have accumulated over the last century, core aspects of the neuronal mechanisms that control locomotion remain obscure. Advances in developmental and molecular biology, combined with new neuroscience methods for recording locomotor activity, have provided us with new opportunities to better our understanding.

The purpose of this Special Issue is to highlight different aspects of the neuronal control of locomotion using different approaches, including molecular biology, neuroscience, biomechanics, and computational approaches, on different model systems.

Assoc. Prof. Turgay Akay
Guest Editor

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All papers will be peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. International Journal of Molecular Sciences is an international peer-reviewed open access semimonthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. There is an Article Processing Charge (APC) for publication in this open access journal. For details about the APC please see here. Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

  • locomotion
  • neuroscience
  • molecular biology
  • genetics
  • gene delivery
  • motion analysis
  • in vivo electrophysiology
  • in vitro electrophysiology
  • central pattern generators
  • sensory feedback

Published Papers (5 papers)

Order results
Result details
Select all
Export citation of selected articles as:

Research

Jump to: Review

Open AccessArticle
Noradrenergic Components of Locomotor Recovery Induced by Intraspinal Grafting of the Embryonic Brainstem in Adult Paraplegic Rats
Int. J. Mol. Sci. 2020, 21(15), 5520; https://0-doi-org.brum.beds.ac.uk/10.3390/ijms21155520 - 01 Aug 2020
Viewed by 652
Abstract
Intraspinal grafting of serotonergic (5-HT) neurons was shown to restore plantar stepping in paraplegic rats. Here we asked whether neurons of other phenotypes contribute to the recovery. The experiments were performed on adult rats after spinal cord total transection. Grafts were injected into [...] Read more.
Intraspinal grafting of serotonergic (5-HT) neurons was shown to restore plantar stepping in paraplegic rats. Here we asked whether neurons of other phenotypes contribute to the recovery. The experiments were performed on adult rats after spinal cord total transection. Grafts were injected into the sub-lesional spinal cord. Two months later, locomotor performance was tested with electromyographic recordings from hindlimb muscles. The role of noradrenergic (NA) innervation was investigated during locomotor performance of spinal grafted and non-grafted rats using intraperitoneal application of α2 adrenergic receptor agonist (clonidine) or antagonist (yohimbine). Morphological analysis of the host spinal cords demonstrated the presence of tyrosine hydroxylase positive (NA) neurons in addition to 5-HT neurons. 5-HT fibers innervated caudal spinal cord areas in the dorsal and ventral horns, central canal, and intermediolateral zone, while the NA fiber distribution was limited to the central canal and intermediolateral zone. 5-HT and NA neurons were surrounded by each other’s axons. Locomotor abilities of the spinal grafted rats, but not in control spinal rats, were facilitated by yohimbine and suppressed by clonidine. Thus, noradrenergic innervation, in addition to 5-HT innervation, plays a potent role in hindlimb movement enhanced by intraspinal grafting of brainstem embryonic tissue in paraplegic rats. Full article
(This article belongs to the Special Issue Neuronal Control of Locomotion)
Show Figures

Figure 1

Review

Jump to: Research

Open AccessReview
Spinal Inhibitory Interneurons: Gatekeepers of Sensorimotor Pathways
Int. J. Mol. Sci. 2021, 22(5), 2667; https://0-doi-org.brum.beds.ac.uk/10.3390/ijms22052667 - 06 Mar 2021
Viewed by 433
Abstract
The ability to sense and move within an environment are complex functions necessary for the survival of nearly all species. The spinal cord is both the initial entry site for peripheral information and the final output site for motor response, placing spinal circuits [...] Read more.
The ability to sense and move within an environment are complex functions necessary for the survival of nearly all species. The spinal cord is both the initial entry site for peripheral information and the final output site for motor response, placing spinal circuits as paramount in mediating sensory responses and coordinating movement. This is partly accomplished through the activation of complex spinal microcircuits that gate afferent signals to filter extraneous stimuli from various sensory modalities and determine which signals are transmitted to higher order structures in the CNS and to spinal motor pathways. A mechanistic understanding of how inhibitory interneurons are organized and employed within the spinal cord will provide potential access points for therapeutics targeting inhibitory deficits underlying various pathologies including sensory and movement disorders. Recent studies using transgenic manipulations, neurochemical profiling, and single-cell transcriptomics have identified distinct populations of inhibitory interneurons which express an array of genetic and/or neurochemical markers that constitute functional microcircuits. In this review, we provide an overview of identified neural components that make up inhibitory microcircuits within the dorsal and ventral spinal cord and highlight the importance of inhibitory control of sensorimotor pathways at the spinal level. Full article
(This article belongs to the Special Issue Neuronal Control of Locomotion)
Show Figures

Figure 1

Open AccessReview
The Effects of Mechanical Scale on Neural Control and the Regulation of Joint Stability
Int. J. Mol. Sci. 2021, 22(4), 2018; https://0-doi-org.brum.beds.ac.uk/10.3390/ijms22042018 - 18 Feb 2021
Viewed by 489
Abstract
Recent work has demonstrated how the size of an animal can affect neural control strategies, showing that passive viscoelastic limb properties have a significant role in determining limb movements in small animals but are less important in large animals. We extend that work [...] Read more.
Recent work has demonstrated how the size of an animal can affect neural control strategies, showing that passive viscoelastic limb properties have a significant role in determining limb movements in small animals but are less important in large animals. We extend that work to consider effects of mechanical scaling on the maintenance of joint integrity; i.e., the prevention of aberrant contact forces within joints that might lead to joint dislocation or cartilage degradation. We first performed a literature review to evaluate how properties of ligaments responsible for joint integrity scale with animal size. Although we found that the cross-sectional area of the anterior cruciate ligament generally scaled with animal size, as expected, the effects of scale on the ligament’s mechanical properties were less clear, suggesting potential adaptations in passive contributions to the maintenance of joint integrity across species. We then analyzed how the neural control of joint stability is altered by body scale. We show how neural control strategies change across mechanical scales, how this scaling is affected by passive muscle properties and the cost function used to specify muscle activations, and the consequences of scaling on internal joint contact forces. This work provides insights into how scale affects the regulation of joint integrity by both passive and active processes and provides directions for studies examining how this regulation might be accomplished by neural systems. Full article
(This article belongs to the Special Issue Neuronal Control of Locomotion)
Show Figures

Figure 1

Open AccessReview
Relative Contribution of Proprioceptive and Vestibular Sensory Systems to Locomotion: Opportunities for Discovery in the Age of Molecular Science
Int. J. Mol. Sci. 2021, 22(3), 1467; https://0-doi-org.brum.beds.ac.uk/10.3390/ijms22031467 - 02 Feb 2021
Viewed by 670
Abstract
Locomotion is a fundamental animal behavior required for survival and has been the subject of neuroscience research for centuries. In terrestrial mammals, the rhythmic and coordinated leg movements during locomotion are controlled by a combination of interconnected neurons in the spinal cord, referred [...] Read more.
Locomotion is a fundamental animal behavior required for survival and has been the subject of neuroscience research for centuries. In terrestrial mammals, the rhythmic and coordinated leg movements during locomotion are controlled by a combination of interconnected neurons in the spinal cord, referred as to the central pattern generator, and sensory feedback from the segmental somatosensory system and supraspinal centers such as the vestibular system. How segmental somatosensory and the vestibular systems work in parallel to enable terrestrial mammals to locomote in a natural environment is still relatively obscure. In this review, we first briefly describe what is known about how the two sensory systems control locomotion and use this information to formulate a hypothesis that the weight of the role of segmental feedback is less important at slower speeds but increases at higher speeds, whereas the weight of the role of vestibular system has the opposite relation. The new avenues presented by the latest developments in molecular sciences using the mouse as the model system allow the direct testing of the hypothesis. Full article
(This article belongs to the Special Issue Neuronal Control of Locomotion)
Show Figures

Figure 1

Open AccessReview
Recent Insights into the Rhythmogenic Core of the Locomotor CPG
Int. J. Mol. Sci. 2021, 22(3), 1394; https://0-doi-org.brum.beds.ac.uk/10.3390/ijms22031394 - 30 Jan 2021
Viewed by 415
Abstract
In order for locomotion to occur, a complex pattern of muscle activation is required. For more than a century, it has been known that the timing and pattern of stepping movements in mammals are generated by neural networks known as central pattern generators [...] Read more.
In order for locomotion to occur, a complex pattern of muscle activation is required. For more than a century, it has been known that the timing and pattern of stepping movements in mammals are generated by neural networks known as central pattern generators (CPGs), which comprise multiple interneuron cell types located entirely within the spinal cord. A genetic approach has recently been successful in identifying several populations of spinal neurons that make up this neural network, as well as the specific role they play during stepping. In spite of this progress, the identity of the neurons responsible for generating the locomotor rhythm and the manner in which they are interconnected have yet to be deciphered. In this review, we summarize key features considered to be expressed by locomotor rhythm-generating neurons and describe the different genetically defined classes of interneurons which have been proposed to be involved. Full article
(This article belongs to the Special Issue Neuronal Control of Locomotion)
Back to TopTop