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Published on: January 9, 2016
Cortical contributions to the stretch reflex response in biceps brachii
M A Krutky1, E J Perreault, G N Lewis
1Department of Biomedical Engineering, Northwestern University, Chicago, IL, USA.
Summary
The biceps M2 response, a long-latency stretch reflex component, appears to use a trans-cortical pathway. This pathway may help organize multi-joint movements and posture.
Area of Science:
- Neuroscience
- Human Motor Control
- Neurophysiology
Background:
- Long-latency stretch reflexes are crucial for postural control and multi-joint movement.
- The specific neural pathways mediating these reflexes, particularly the M2 response in the biceps brachii, remain under investigation.
Purpose of the Study:
- To determine if the M2 response in the biceps brachii muscle is mediated via a trans-cortical pathway.
- To explore the role of transcranial magnetic stimulation (TMS) in modulating this reflex pathway.
Main Methods:
- Subjects performed ramp-and-hold perturbations on the biceps brachii.
- Both ipsilateral and contralateral transcranial magnetic stimulation (TMS) were applied.
- Participants were instructed to either resist or not resist the perturbations.
Main Results:
- The biceps M2 response showed modulation based on the task demands.
- Contralateral TMS facilitated the biceps M2 response.
- These findings support the involvement of a trans-cortical pathway.
Conclusions:
- The M2 response in the biceps brachii is likely mediated through a trans-cortical pathway.
- This pathway plays a role in the neural organization of movements and posture.
- Further research is needed to consistently inhibit this pathway and understand its full impact on the long-latency stretch reflex.
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