Influence of serotonin on the long-term muscle contraction of the Kohnstamm phenomenon
Abstract Neuromodulation plays a central role in human movement control. An imbalance of neurotransmitters, especially dopamine and serotonin, can be associated with various neurological disorders causing tremors or spasms. Specifically, serotonin was shown to scale motoneuron excitability following...
Saved in:
| Main Authors: | , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Nature Portfolio
2025-05-01
|
| Series: | Scientific Reports |
| Online Access: | https://doi.org/10.1038/s41598-025-00444-1 |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| _version_ | 1849726326929358848 |
|---|---|
| author | Annika Schmidt Tobias Meindl Alin Albu-Schäffer David W. Franklin Philipp Stratmann |
| author_facet | Annika Schmidt Tobias Meindl Alin Albu-Schäffer David W. Franklin Philipp Stratmann |
| author_sort | Annika Schmidt |
| collection | DOAJ |
| description | Abstract Neuromodulation plays a central role in human movement control. An imbalance of neurotransmitters, especially dopamine and serotonin, can be associated with various neurological disorders causing tremors or spasms. Specifically, serotonin was shown to scale motoneuron excitability following intense muscle contractions, affecting short-latency reflexes. Likely, it may also influence motoneuron modulation in prolonged contractions, although this lacks experimental evidence. An intriguing test case for this hypothesis is presented by the Kohnstamm phenomenon, where sustained muscle contractions lead to prolonged amplified EMG activity and involuntary motions, aligning with the timescale of serotonergic amplification. The suspected serotonin influence on this effect was tested in a placebo-controlled human user study with 14 participants, where half were administered the serotonin antagonist Cyproheptadine and the other half a placebo. Comparing EMG and force responses after inducing the Kohnstamm phenomenon in the deltoid muscles revealed statistically significant faster EMG decay with the serotonin antagonist, while decay remained consistent in the placebo group compared to the response of the same participant group without medication. The force measurements showed the same trend, although no significance. This provides new data-based evidence that serotonin contributes to long-term motoneuron modulation, extending previous findings about the dedicated role and influence of this neurotransmitter. Additionally, the work suggests the phenomenon as an interesting test case to investigate the dedicated involvement of different neurocontrol mechanisms such as Persistent Inward Currents. |
| format | Article |
| id | doaj-art-98f32dfa3ceb4fab974d493d8224d3c1 |
| institution | DOAJ |
| issn | 2045-2322 |
| language | English |
| publishDate | 2025-05-01 |
| publisher | Nature Portfolio |
| record_format | Article |
| series | Scientific Reports |
| spelling | doaj-art-98f32dfa3ceb4fab974d493d8224d3c12025-08-20T03:10:13ZengNature PortfolioScientific Reports2045-23222025-05-0115111110.1038/s41598-025-00444-1Influence of serotonin on the long-term muscle contraction of the Kohnstamm phenomenonAnnika Schmidt0Tobias Meindl1Alin Albu-Schäffer2David W. Franklin3Philipp Stratmann4TUM School of Computation, Information and Technology, Technical University of Munich (TUM)Department of Neurology, University Hospital rechts der Isar, Technical University of MunichTUM School of Computation, Information and Technology, Technical University of Munich (TUM)Munich Institute of Robotics and Machine Intelligence (MIRMI), Technical University of Munich (TUM)TUM School of Computation, Information and Technology, Technical University of Munich (TUM)Abstract Neuromodulation plays a central role in human movement control. An imbalance of neurotransmitters, especially dopamine and serotonin, can be associated with various neurological disorders causing tremors or spasms. Specifically, serotonin was shown to scale motoneuron excitability following intense muscle contractions, affecting short-latency reflexes. Likely, it may also influence motoneuron modulation in prolonged contractions, although this lacks experimental evidence. An intriguing test case for this hypothesis is presented by the Kohnstamm phenomenon, where sustained muscle contractions lead to prolonged amplified EMG activity and involuntary motions, aligning with the timescale of serotonergic amplification. The suspected serotonin influence on this effect was tested in a placebo-controlled human user study with 14 participants, where half were administered the serotonin antagonist Cyproheptadine and the other half a placebo. Comparing EMG and force responses after inducing the Kohnstamm phenomenon in the deltoid muscles revealed statistically significant faster EMG decay with the serotonin antagonist, while decay remained consistent in the placebo group compared to the response of the same participant group without medication. The force measurements showed the same trend, although no significance. This provides new data-based evidence that serotonin contributes to long-term motoneuron modulation, extending previous findings about the dedicated role and influence of this neurotransmitter. Additionally, the work suggests the phenomenon as an interesting test case to investigate the dedicated involvement of different neurocontrol mechanisms such as Persistent Inward Currents.https://doi.org/10.1038/s41598-025-00444-1 |
| spellingShingle | Annika Schmidt Tobias Meindl Alin Albu-Schäffer David W. Franklin Philipp Stratmann Influence of serotonin on the long-term muscle contraction of the Kohnstamm phenomenon Scientific Reports |
| title | Influence of serotonin on the long-term muscle contraction of the Kohnstamm phenomenon |
| title_full | Influence of serotonin on the long-term muscle contraction of the Kohnstamm phenomenon |
| title_fullStr | Influence of serotonin on the long-term muscle contraction of the Kohnstamm phenomenon |
| title_full_unstemmed | Influence of serotonin on the long-term muscle contraction of the Kohnstamm phenomenon |
| title_short | Influence of serotonin on the long-term muscle contraction of the Kohnstamm phenomenon |
| title_sort | influence of serotonin on the long term muscle contraction of the kohnstamm phenomenon |
| url | https://doi.org/10.1038/s41598-025-00444-1 |
| work_keys_str_mv | AT annikaschmidt influenceofserotoninonthelongtermmusclecontractionofthekohnstammphenomenon AT tobiasmeindl influenceofserotoninonthelongtermmusclecontractionofthekohnstammphenomenon AT alinalbuschaffer influenceofserotoninonthelongtermmusclecontractionofthekohnstammphenomenon AT davidwfranklin influenceofserotoninonthelongtermmusclecontractionofthekohnstammphenomenon AT philippstratmann influenceofserotoninonthelongtermmusclecontractionofthekohnstammphenomenon |