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
Evidence for a subcortical contribution to intracortical facilitation
Intracortical facilitation (ICF) describes the facilitation of an EMG response (motor evoked potential) to a suprathreshold pulse (S2) of transcranial magnetic stimulation (TMS) by a preceding subthreshold pulse (S1) given 10–15 ms earlier. ICF is widely assumed to originate from intracortical mechanisms. In this study, we used spinal H‐reflexes to test whether subcortical mechanisms can also contribute to the facilitation. Measurements were performed in the upper limb muscle flexor carpi radialis in 17 healthy volunteers, and in the lower limb muscle soleus in 16 healthy volunteers. S2 given alone facilitated the H‐reflex. When S1 preceded S2 by 10 ms, the amount of facilitation increased, compatible with ICF. However, S1 given alone also facilitated the H‐reflex, suggesting that it had evoked descending activity even though its intensity was well below resting motor threshold. Across participants, the amount of H‐reflex facilitation from S1 alone was proportional to the degree of H‐reflex facilitation with combined S1–S2. These results indicate that subcortical mechanisms can contribute to ICF and potentially add to the variability of the ICF measure reported in previous studies.
Publication data is maintained in RPS. Visit https://rps.ucl.ac.uk
 More search options
UCL Researchers
Clinical and Movement Neurosciences
University College London - Gower Street - London - WC1E 6BT Tel:+44 (0)20 7679 2000

© UCL 1999–2011

Search by