The CPGs for Limbed Locomotion–Facts and Fiction
The neuronal networks that generate locomotion are well understood in swimming animals such as the lamprey, zebrafish and tadpole. The networks controlling locomotion in tetrapods remain, however, still enigmatic with an intricate motor pattern required for the control of the entire limb during the...
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| Format: | Article |
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MDPI AG
2021-05-01
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| Series: | International Journal of Molecular Sciences |
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| Online Access: | https://www.mdpi.com/1422-0067/22/11/5882 |
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| author | Sten Grillner Alexander Kozlov |
| author_facet | Sten Grillner Alexander Kozlov |
| author_sort | Sten Grillner |
| collection | DOAJ |
| description | The neuronal networks that generate locomotion are well understood in swimming animals such as the lamprey, zebrafish and tadpole. The networks controlling locomotion in tetrapods remain, however, still enigmatic with an intricate motor pattern required for the control of the entire limb during the support, lift off, and flexion phase, and most demandingly when the limb makes contact with ground again. It is clear that the inhibition that occurs between bursts in each step cycle is produced by V2b and V1 interneurons, and that a deletion of these interneurons leads to synchronous flexor–extensor bursting. The ability to generate rhythmic bursting is distributed over all segments comprising part of the central pattern generator network (CPG). It is unclear how the rhythmic bursting is generated; however, Shox2, V2a and HB9 interneurons do contribute. To deduce a possible organization of the locomotor CPG, simulations have been elaborated. The motor pattern has been simulated in considerable detail with a network composed of unit burst generators; one for each group of close synergistic muscle groups at each joint. This unit burst generator model can reproduce the complex burst pattern with a constant flexion phase and a shortened extensor phase as the speed increases. Moreover, the unit burst generator model is versatile and can generate both forward and backward locomotion. |
| first_indexed | 2024-03-10T10:51:56Z |
| format | Article |
| id | doaj.art-ad0480a401a14313a7b9a9d95524fa09 |
| institution | Directory Open Access Journal |
| issn | 1661-6596 1422-0067 |
| language | English |
| last_indexed | 2024-03-10T10:51:56Z |
| publishDate | 2021-05-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | International Journal of Molecular Sciences |
| spelling | doaj.art-ad0480a401a14313a7b9a9d95524fa092023-11-21T22:08:42ZengMDPI AGInternational Journal of Molecular Sciences1661-65961422-00672021-05-012211588210.3390/ijms22115882The CPGs for Limbed Locomotion–Facts and FictionSten Grillner0Alexander Kozlov1Department of Neuroscience, Karolinska Institutet, SE-17177 Stockholm, SwedenDepartment of Neuroscience, Karolinska Institutet, SE-17177 Stockholm, SwedenThe neuronal networks that generate locomotion are well understood in swimming animals such as the lamprey, zebrafish and tadpole. The networks controlling locomotion in tetrapods remain, however, still enigmatic with an intricate motor pattern required for the control of the entire limb during the support, lift off, and flexion phase, and most demandingly when the limb makes contact with ground again. It is clear that the inhibition that occurs between bursts in each step cycle is produced by V2b and V1 interneurons, and that a deletion of these interneurons leads to synchronous flexor–extensor bursting. The ability to generate rhythmic bursting is distributed over all segments comprising part of the central pattern generator network (CPG). It is unclear how the rhythmic bursting is generated; however, Shox2, V2a and HB9 interneurons do contribute. To deduce a possible organization of the locomotor CPG, simulations have been elaborated. The motor pattern has been simulated in considerable detail with a network composed of unit burst generators; one for each group of close synergistic muscle groups at each joint. This unit burst generator model can reproduce the complex burst pattern with a constant flexion phase and a shortened extensor phase as the speed increases. Moreover, the unit burst generator model is versatile and can generate both forward and backward locomotion.https://www.mdpi.com/1422-0067/22/11/5882locomotionpremotor interneuronsunit burst generator networkCPG simulations |
| spellingShingle | Sten Grillner Alexander Kozlov The CPGs for Limbed Locomotion–Facts and Fiction International Journal of Molecular Sciences locomotion premotor interneurons unit burst generator network CPG simulations |
| title | The CPGs for Limbed Locomotion–Facts and Fiction |
| title_full | The CPGs for Limbed Locomotion–Facts and Fiction |
| title_fullStr | The CPGs for Limbed Locomotion–Facts and Fiction |
| title_full_unstemmed | The CPGs for Limbed Locomotion–Facts and Fiction |
| title_short | The CPGs for Limbed Locomotion–Facts and Fiction |
| title_sort | cpgs for limbed locomotion facts and fiction |
| topic | locomotion premotor interneurons unit burst generator network CPG simulations |
| url | https://www.mdpi.com/1422-0067/22/11/5882 |
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