Cargando…

Long-latency reflexes account for limb biomechanics through several supraspinal pathways

Accurate control of body posture is enforced by a multitude of corrective actions operating over a range of time scales. The earliest correction is the short-latency reflex (SLR) which occurs between 20–45 ms following a sudden displacement of the limb and is generated entirely by spinal circuits. I...

Descripción completa

Detalles Bibliográficos
Autor principal: Kurtzer, Isaac L.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Frontiers Media S.A. 2015
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4310276/
https://www.ncbi.nlm.nih.gov/pubmed/25688187
http://dx.doi.org/10.3389/fnint.2014.00099
_version_ 1782354840833228800
author Kurtzer, Isaac L.
author_facet Kurtzer, Isaac L.
author_sort Kurtzer, Isaac L.
collection PubMed
description Accurate control of body posture is enforced by a multitude of corrective actions operating over a range of time scales. The earliest correction is the short-latency reflex (SLR) which occurs between 20–45 ms following a sudden displacement of the limb and is generated entirely by spinal circuits. In contrast, voluntary reactions are generated by a highly distributed network but at a significantly longer delay after stimulus onset (greater than 100 ms). Between these two epochs is the long-latency reflex (LLR) (around 50–100 ms) which acts more rapidly than voluntary reactions but shares some supraspinal pathways and functional capabilities. In particular, the LLR accounts for the arm’s biomechanical properties rather than only responding to local muscle stretch like the SLR. This paper will review how the LLR accounts for the arm’s biomechanical properties and the supraspinal pathways supporting this ability. Relevant experimental paradigms include clinical studies, non-invasive brain stimulation, neural recordings in monkeys, and human behavioral studies. The sum of this effort indicates that primary motor cortex and reticular formation (RF) contribute to the LLR either by generating or scaling its structured response appropriate for the arm’s biomechanics whereas the cerebellum scales the magnitude of the feedback response. Additional putative pathways are discussed as well as potential research lines.
format Online
Article
Text
id pubmed-4310276
institution National Center for Biotechnology Information
language English
publishDate 2015
publisher Frontiers Media S.A.
record_format MEDLINE/PubMed
spelling pubmed-43102762015-02-16 Long-latency reflexes account for limb biomechanics through several supraspinal pathways Kurtzer, Isaac L. Front Integr Neurosci Neuroscience Accurate control of body posture is enforced by a multitude of corrective actions operating over a range of time scales. The earliest correction is the short-latency reflex (SLR) which occurs between 20–45 ms following a sudden displacement of the limb and is generated entirely by spinal circuits. In contrast, voluntary reactions are generated by a highly distributed network but at a significantly longer delay after stimulus onset (greater than 100 ms). Between these two epochs is the long-latency reflex (LLR) (around 50–100 ms) which acts more rapidly than voluntary reactions but shares some supraspinal pathways and functional capabilities. In particular, the LLR accounts for the arm’s biomechanical properties rather than only responding to local muscle stretch like the SLR. This paper will review how the LLR accounts for the arm’s biomechanical properties and the supraspinal pathways supporting this ability. Relevant experimental paradigms include clinical studies, non-invasive brain stimulation, neural recordings in monkeys, and human behavioral studies. The sum of this effort indicates that primary motor cortex and reticular formation (RF) contribute to the LLR either by generating or scaling its structured response appropriate for the arm’s biomechanics whereas the cerebellum scales the magnitude of the feedback response. Additional putative pathways are discussed as well as potential research lines. Frontiers Media S.A. 2015-01-29 /pmc/articles/PMC4310276/ /pubmed/25688187 http://dx.doi.org/10.3389/fnint.2014.00099 Text en Copyright © 2015 Kurtzer. http://creativecommons.org/licenses/by/4.0/ This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution and reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
spellingShingle Neuroscience
Kurtzer, Isaac L.
Long-latency reflexes account for limb biomechanics through several supraspinal pathways
title Long-latency reflexes account for limb biomechanics through several supraspinal pathways
title_full Long-latency reflexes account for limb biomechanics through several supraspinal pathways
title_fullStr Long-latency reflexes account for limb biomechanics through several supraspinal pathways
title_full_unstemmed Long-latency reflexes account for limb biomechanics through several supraspinal pathways
title_short Long-latency reflexes account for limb biomechanics through several supraspinal pathways
title_sort long-latency reflexes account for limb biomechanics through several supraspinal pathways
topic Neuroscience
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4310276/
https://www.ncbi.nlm.nih.gov/pubmed/25688187
http://dx.doi.org/10.3389/fnint.2014.00099
work_keys_str_mv AT kurtzerisaacl longlatencyreflexesaccountforlimbbiomechanicsthroughseveralsupraspinalpathways