QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

HOME  |   SEARCH  |   ARCHIVE  |   SUBSCRIBE  |   CONTACT  |   HELP

The Journal of Neuroscience, May 20, 2009, 29(20):6616-6624; doi:10.1523/JNEUROSCI.0272-09.2009

This Article Full Text Full Text (PDF) Submit an eLetter Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Google Scholar Articles by Williams, E. R. Articles by Baker, S. N. PubMed PubMed Citation Articles by Williams, E. R. Articles by Baker, S. N.

 Previous Article  |  Next Article 

Behavioral/Systems/Cognitive
Renshaw Cell Recurrent Inhibition Improves Physiological Tremor by Reducing Corticomuscular Coupling at 10 Hz

Elizabeth R. Williams and Stuart N. Baker

Institute of Neuroscience, Newcastle University, Newcastle upon Tyne NE2 4HH, United Kingdom

Correspondence should be addressed to Prof. Stuart N. Baker, Institute of Neuroscience, Newcastle University, Henry Wellcome Building, Newcastle upon Tyne NE2 4HH, UK. Email: stuart.baker{at}ncl.ac.uk

Corticomuscular coherence between the primary motor cortex (M1) and hand muscle electromyograms (EMG) occurs at 20 Hz but is rarely seen at 10 Hz. This is unexpected, because M1 has oscillations at both frequencies, which are effectively transmitted to the spinal cord via the corticospinal tract. We have previously speculated that a specific "neural filter" may selectively reduce coherence at 10 Hz. This would have functional utility in minimizing physiological tremor, which often has a dominant component around this frequency. Recurrent inhibition via Renshaw cells in the spinal cord is a putative neural substrate for such a filter. Here we investigate this system in more detail with a biophysically based computational model. Renshaw cell recurrent inhibition reduced EMG oscillations at 10 Hz, and also reduced corticomuscular coherence at this frequency (from 0.038 to 0.014). Renshaw cell inhibitory feedback also generated synchronous oscillations in the motoneuron pool at 30 Hz. We show that the effects at 10 Hz and 30 Hz can both be understood from the dynamics of the inhibitory feedback loop. We conclude that recurrent inhibition certainly plays an important role in reducing 10 Hz oscillations in muscle, thereby decreasing tremor amplitude. However, our quantitative results suggest it is unlikely to be the only system for tremor reduction, and probably acts in concert with other neural circuits which remain to be elucidated.

---

Received Jan. 17, 2009; revised March 25, 2009; accepted March 27, 2009.

Correspondence should be addressed to Prof. Stuart N. Baker, Institute of Neuroscience, Newcastle University, Henry Wellcome Building, Newcastle upon Tyne NE2 4HH, UK. Email: stuart.baker{at}ncl.ac.uk

This article has been cited by other articles:

				E. R. Williams, D. S. Soteropoulos, and S. N. Baker Coherence Between Motor Cortical Activity and Peripheral Discontinuities During Slow Finger Movements J Neurophysiol, August 1, 2009; 102(2): 1296 - 1309. [Abstract] [Full Text] [PDF]

Home  |   Search  |   Archive  |   Subscribe  |   Contact  |   Help