Different Segments within Vertebrate Muscles Can Operate on Different Regions of Their Force–Length Relationships
To relate in vivo behavior of fascicle segments within a muscle to their in vitro force-length relationships, we examined the strain behavior of paired segments within each of three vertebrate muscles. After determining in vivo muscle activity patterns and length changes of in-series segments within...
Published in: | Integrative and Comparative Biology |
---|---|
Main Authors: | , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
Oxford University Press (OUP)
2018
|
Subjects: | |
Online Access: | http://nrs.harvard.edu/urn-3:HUL.InstRepos:40935569 https://doi.org/10.1093/icb/icy040 |
id |
ftharvardudash:oai:dash.harvard.edu:1/40935569 |
---|---|
record_format |
openpolar |
spelling |
ftharvardudash:oai:dash.harvard.edu:1/40935569 2023-05-15T18:05:44+02:00 Different Segments within Vertebrate Muscles Can Operate on Different Regions of Their Force–Length Relationships Ahn, A N Konow, Nicolai Tijs, Chris Biewener, Andrew 2018-06-13 application/pdf http://nrs.harvard.edu/urn-3:HUL.InstRepos:40935569 https://doi.org/10.1093/icb/icy040 en_US eng Oxford University Press (OUP) Integrative and Comparative Biology Ahn, A N, N. Konow, C. Tijs, and A A Biewener. 2018. "Different Segments within Vertebrate Muscles Can Operate on Different Regions of Their Force-Length Relationships." Integrative and Comparative Biology 58 (2): 219-231. 1540-7063 1557-7023 http://nrs.harvard.edu/urn-3:HUL.InstRepos:40935569 doi:10.1093/icb/icy040 muscle heterogeneity force-length relationship Journal Article 2018 ftharvardudash https://doi.org/10.1093/icb/icy040 2022-04-04T11:36:39Z To relate in vivo behavior of fascicle segments within a muscle to their in vitro force-length relationships, we examined the strain behavior of paired segments within each of three vertebrate muscles. After determining in vivo muscle activity patterns and length changes of in-series segments within the semimembranosus muscle (SM) in the American Toad (Bufo americanus) during hopping and within the sternohyoid (SH) muscle in the rat (Rattus rattus) during swallowing, and of spatially separated fascicles within the medial gastrocnemius (MG) muscle in the rat during trotting, we measured their corresponding in vitro (toad) or in situ (rat) force–length relationships (FLRs). For all three muscles, in vivo strain heterogeneity lasted for about 36–57% of the behavior cycle, during which one segment or fascicle shortened while the other segment or fascicle simultaneously lengthened. In the toad SM, the proximal segment shortened from the descending limb across the plateau of its FLR from 1.12 to 0.91 of its optimal length (Lo), while the distal segment lengthened (by 0.04 ± 0.04 Lo) before shortening down the ascending limb from 0.94 to 0.83 Lo. In the rat SH muscle, the proximal segment tended to shorten on its ascending limb from 0.90 to 0.85 Lo while the distal segment tended to lengthen across Lo (0.96–1.12 Lo). In the rat MG muscle, in vivo strains of proximal fascicles ranged from 0.72 to 1.02 Lo, while the distal fascicles ranged from 0.88 to 1.11 Lo. Even though the timing of muscle activation patterns were similar between segments, the heterogeneous strain patterns of fascicle segments measured in vivo coincided with different operating ranges across their FLRs simultaneously, implying differences in force–velocity behavior as well. The three vertebrate skeletal muscles represent a diversity of fiber architectures and functions and suggest that patterns of in vivo contractile strain and the operating range over the FLR in one muscle region does not necessarily represent other regions within the same muscle. Organismic and Evolutionary Biology Accepted Manuscript Article in Journal/Newspaper Rattus rattus Harvard University: DASH - Digital Access to Scholarship at Harvard Integrative and Comparative Biology 58 2 219 231 |
institution |
Open Polar |
collection |
Harvard University: DASH - Digital Access to Scholarship at Harvard |
op_collection_id |
ftharvardudash |
language |
English |
topic |
muscle heterogeneity force-length relationship |
spellingShingle |
muscle heterogeneity force-length relationship Ahn, A N Konow, Nicolai Tijs, Chris Biewener, Andrew Different Segments within Vertebrate Muscles Can Operate on Different Regions of Their Force–Length Relationships |
topic_facet |
muscle heterogeneity force-length relationship |
description |
To relate in vivo behavior of fascicle segments within a muscle to their in vitro force-length relationships, we examined the strain behavior of paired segments within each of three vertebrate muscles. After determining in vivo muscle activity patterns and length changes of in-series segments within the semimembranosus muscle (SM) in the American Toad (Bufo americanus) during hopping and within the sternohyoid (SH) muscle in the rat (Rattus rattus) during swallowing, and of spatially separated fascicles within the medial gastrocnemius (MG) muscle in the rat during trotting, we measured their corresponding in vitro (toad) or in situ (rat) force–length relationships (FLRs). For all three muscles, in vivo strain heterogeneity lasted for about 36–57% of the behavior cycle, during which one segment or fascicle shortened while the other segment or fascicle simultaneously lengthened. In the toad SM, the proximal segment shortened from the descending limb across the plateau of its FLR from 1.12 to 0.91 of its optimal length (Lo), while the distal segment lengthened (by 0.04 ± 0.04 Lo) before shortening down the ascending limb from 0.94 to 0.83 Lo. In the rat SH muscle, the proximal segment tended to shorten on its ascending limb from 0.90 to 0.85 Lo while the distal segment tended to lengthen across Lo (0.96–1.12 Lo). In the rat MG muscle, in vivo strains of proximal fascicles ranged from 0.72 to 1.02 Lo, while the distal fascicles ranged from 0.88 to 1.11 Lo. Even though the timing of muscle activation patterns were similar between segments, the heterogeneous strain patterns of fascicle segments measured in vivo coincided with different operating ranges across their FLRs simultaneously, implying differences in force–velocity behavior as well. The three vertebrate skeletal muscles represent a diversity of fiber architectures and functions and suggest that patterns of in vivo contractile strain and the operating range over the FLR in one muscle region does not necessarily represent other regions within the same muscle. Organismic and Evolutionary Biology Accepted Manuscript |
format |
Article in Journal/Newspaper |
author |
Ahn, A N Konow, Nicolai Tijs, Chris Biewener, Andrew |
author_facet |
Ahn, A N Konow, Nicolai Tijs, Chris Biewener, Andrew |
author_sort |
Ahn, A N |
title |
Different Segments within Vertebrate Muscles Can Operate on Different Regions of Their Force–Length Relationships |
title_short |
Different Segments within Vertebrate Muscles Can Operate on Different Regions of Their Force–Length Relationships |
title_full |
Different Segments within Vertebrate Muscles Can Operate on Different Regions of Their Force–Length Relationships |
title_fullStr |
Different Segments within Vertebrate Muscles Can Operate on Different Regions of Their Force–Length Relationships |
title_full_unstemmed |
Different Segments within Vertebrate Muscles Can Operate on Different Regions of Their Force–Length Relationships |
title_sort |
different segments within vertebrate muscles can operate on different regions of their force–length relationships |
publisher |
Oxford University Press (OUP) |
publishDate |
2018 |
url |
http://nrs.harvard.edu/urn-3:HUL.InstRepos:40935569 https://doi.org/10.1093/icb/icy040 |
genre |
Rattus rattus |
genre_facet |
Rattus rattus |
op_relation |
Integrative and Comparative Biology Ahn, A N, N. Konow, C. Tijs, and A A Biewener. 2018. "Different Segments within Vertebrate Muscles Can Operate on Different Regions of Their Force-Length Relationships." Integrative and Comparative Biology 58 (2): 219-231. 1540-7063 1557-7023 http://nrs.harvard.edu/urn-3:HUL.InstRepos:40935569 doi:10.1093/icb/icy040 |
op_doi |
https://doi.org/10.1093/icb/icy040 |
container_title |
Integrative and Comparative Biology |
container_volume |
58 |
container_issue |
2 |
container_start_page |
219 |
op_container_end_page |
231 |
_version_ |
1766177247017828352 |