UCL  IRIS
Institutional Research Information Service
UCL Logo
Please report any queries concerning the funding data grouped in the sections named "Externally Awarded" or "Internally Disbursed" (shown on the profile page) to your Research Finance Administrator. Your can find your Research Finance Administrator at https://www.ucl.ac.uk/finance/research/rs-contacts.php by entering your department
Please report any queries concerning the student data shown on the profile page to:

Email: portico-services@ucl.ac.uk

Help Desk: http://www.ucl.ac.uk/ras/portico/helpdesk
Publication Detail
Ipsilateral cortical stimulation inhibited the long-latency response to stretch in the long finger flexors in humans.
  • Publication Type:
    Journal article
  • Publication Sub Type:
    Journal Article
  • Authors:
    Taylor JL, Fogel W, Day BL, Rothwell JC
  • Publication date:
    01/11/1995
  • Pagination:
    821, 831
  • Journal:
    J Physiol
  • Volume:
    488 ( Pt 3)
  • Issue:
    Pt 3
  • Status:
    Published
  • Country:
    England
  • Print ISSN:
    0022-3751
  • Language:
    eng
  • Keywords:
    Electromyography, Evoked Potentials, Motor, Fingers, Humans, Magnetics, Muscle Contraction, Muscle, Skeletal, Time Factors
Abstract
1. Transcranial magnetic stimulation over the motor cortex of one hemisphere is known to decrease the excitability of the motor cortex of the other hemisphere. We investigated the effect of this interhemispheric or transcallosal inhibition of the motor cortex on the reflex response to stretch in the long flexors of the fingers in human subjects. 2. Stretch of the long finger flexors, through extension of the proximal interphalangeal joints with a torque pulse, resulted in a reflex EMG response with short- and long-latency components. Magnetic stimulation was applied over the motor cortex ipsilateral to the muscles being stretched. When a magnetic shock but not stretch was given, a decrease in background EMG in the ipsilateral finger flexors occurred at a latency of 33 +/- 6.2 ms after the stimulus and with a duration of 25 +/- 8.5 ms. 3. If the magnetic shock and the stretch were given at appropriate interstimulus intervals, the long-latency stretch reflex (LLSR) showed inhibition in all subjects. LLSR was reduced to 49.2 +/- 19% (S.D.; n = 9) of the area of the control response. 4. The LLSR did not act as a single event in response to the magnetic shock. That is, part of the LLSR could be reduced in amplitude while the remainder was unaffected. The reduction in LLSR had an onset latency of 27 +/- 3.8 ms after the magnetic stimulus and a duration of 29-55 ms. Inhibition was only obvious when this interval after the magnetic stimulus coincided with the LLSR. 5. In most subjects the short-latency stretch reflex (SLSR) also showed some inhibition (83.4 +/- 11.2% of the control). However, this was less than the effect on the LLSR in all subjects. 6. The site of stimulation, over the ipsilateral motor cortex, was specific for inhibition of the LLSR. When the coil was moved anteriorly or to the midline, inhibition was significantly decreased. 7. We suggest that the inhibition of the LLSR of the long flexors of the fingers resulted from a reduction in excitability of the motor cortex produced by an inhibitory transcallosal pathway and conclude that the LLSR in this muscle has a transcortical component.
Publication data is maintained in RPS. Visit https://rps.ucl.ac.uk
 More search options
UCL Researchers
Author
UCL Queen Square Institute of Neurology
Author
Clinical and Movement Neurosciences
University College London - Gower Street - London - WC1E 6BT Tel:+44 (0)20 7679 2000

© UCL 1999–2011

Search by