PMID- 21540341
OWN - NLM
STAT- MEDLINE
DCOM- 20120315
LR  - 20220321
IS  - 1469-7793 (Electronic)
IS  - 0022-3751 (Print)
IS  - 0022-3751 (Linking)
VI  - 589
IP  - Pt 12
DP  - 2011 Jun 15
TI  - Direct demonstration of inhibitory interactions between long interval 
      intracortical inhibition and short interval intracortical inhibition.
PG  - 2955-62
LID - 10.1113/jphysiol.2011.207928 [doi]
AB  - A subthreshold conditioning stimulation (CS) suppresses the motor-evoked 
      potential (MEP) generated by a test stimulation (TS) at interstimulus intervals 
      (ISIs) of 1-5ms in a paired-pulse transcranial magnetic stimulation (TMS) 
      protocol, a phenomenon termed short interval intracortical inhibition (SICI). 
      Intracortical facilitation (ICF) occurs at ISIs of 7-30ms. Long interval 
      intracortical inhibition (LICI) is elicited with suprathreshold CS preceding the 
      TS at ISIs of 50-200 ms. Previous studies showed that SICI is decreased in the 
      presence of LICI but whether this is due to changes in descending indirect waves 
      (I-waves) induced by LICI or true inhibitory interactions between LICI and SICI 
      has not been resolved. To address this issue, we recorded I-waves in two patients 
      with implanted cervical epidural electrodes and investigated how SICI and ICF 
      changed I-waves in the presence of LICI. SICI alone reduced late I-waves but in 
      the presence of LICI, neither the I-waves nor the MEP were further inhibited by 
      SICI. ICF alone increased MEP amplitude but the I-waves were not facilitated. 
      There was no change of ICF in the presence of LICI compared with ICF alone. We 
      conclude that decreased SICI in the presence of LICI is not due to changes in 
      I-wave content induced by LICI and is caused by their interactions at the 
      cortical level.
FAU - Ni, Zhen
AU  - Ni Z
AD  - 7MC-411, Toronto Western Hospital, 399 Bathurst Street, Toronto, Ontario, M5T 
      2S8, Canada.
FAU - Gunraj, Carolyn
AU  - Gunraj C
FAU - Wagle-Shukla, Aparna
AU  - Wagle-Shukla A
FAU - Udupa, Kaviraja
AU  - Udupa K
FAU - Mazzella, Filomena
AU  - Mazzella F
FAU - Lozano, Andres M
AU  - Lozano AM
FAU - Chen, Robert
AU  - Chen R
LA  - eng
GR  - DFF 88348/Canadian Institutes of Health Research/Canada
GR  - MOP 62917/Canadian Institutes of Health Research/Canada
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
DEP - 20110503
PL  - England
TA  - J Physiol
JT  - The Journal of physiology
JID - 0266262
SB  - IM
MH  - Adult
MH  - Humans
MH  - Male
MH  - Motor Cortex/*physiology
MH  - Movement/*physiology
MH  - Nerve Net/*physiology
MH  - Neural Inhibition/*physiology
MH  - Pyramidal Tracts/*physiology
MH  - Reaction Time/*physiology
PMC - PMC3139079
EDAT- 2011/05/05 06:00
MHDA- 2012/03/16 06:00
PMCR- 2012/06/15
CRDT- 2011/05/05 06:00
PHST- 2011/05/05 06:00 [entrez]
PHST- 2011/05/05 06:00 [pubmed]
PHST- 2012/03/16 06:00 [medline]
PHST- 2012/06/15 00:00 [pmc-release]
AID - jphysiol.2011.207928 [pii]
AID - 10.1113/jphysiol.2011.207928 [doi]
PST - ppublish
SO  - J Physiol. 2011 Jun 15;589(Pt 12):2955-62. doi: 10.1113/jphysiol.2011.207928. 
      Epub 2011 May 3.