PMID- 24353299
OWN - NLM
STAT- MEDLINE
DCOM- 20141107
LR  - 20191210
IS  - 1522-1598 (Electronic)
IS  - 0022-3077 (Linking)
VI  - 111
IP  - 6
DP  - 2014 Mar
TI  - Effects of short-latency afferent inhibition on short-interval intracortical 
      inhibition.
PG  - 1350-61
LID - 10.1152/jn.00613.2013 [doi]
AB  - Peripheral nerve stimulation inhibits the motor cortex, and the process has been 
      termed short-latency afferent inhibition (SAI) at interstimulus intervals (ISIs) 
      of  approximately 20 ms. The objective of the present study was to test how SAI interacts with 
      short-interval intracortical inhibition (SICI) under different stimulation 
      conditions. We studied 20 healthy volunteers. Surface electromyogram was recorded 
      from the first dorsal interosseous muscle. Using paired- and triple-pulse 
      paradigms, we investigated how SAI interacts with SICI under these different 
      conditions. The effects of different conditioning stimulus (CS) intensities 
      (0.6-0.9 active motor threshold), SAI latencies (23 and 25 ms), and ISIs (2 and 3 
      ms) for SICI were examined in rest and active conditions. SAI had inhibitory 
      interactions with SICI at different CS intensities for rest or active SICI, at 
      SAI latencies of 23 and 25 ms. This interaction occurred at weak CS intensities 
      for SICI when there was no inhibition, and SICI became facilitatory in the 
      presence of SAI. This can be explained by SICI inhibiting SAI and not by 
      saturation of inhibition. The interaction between SAI and SICI was greater for 
      SICI at ISI of 3 ms than for ISI of 2 ms, suggesting that different circuits may 
      be activated at these ISIs. We conclude that SAI and SICI have inhibitory 
      interactions that are influenced by factors such as ISI and muscle activities, 
      which should be considered in design and interpretation of cortical interaction 
      studies.
FAU - Udupa, Kaviraja
AU  - Udupa K
AD  - Division of Neurology, Department of Medicine, University of Toronto, Toronto, 
      Ontario, Canada; and Division of Brain, Imaging and Behaviour-Systems 
      Neuroscience, Toronto Western Research Institute, Toronto, Ontario, Canada.
FAU - Ni, Zhen
AU  - Ni Z
FAU - Gunraj, Carolyn
AU  - Gunraj C
FAU - Chen, Robert
AU  - Chen R
LA  - eng
GR  - MOP 62917/Canadian Institutes of Health Research/Canada
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
DEP - 20131218
PL  - United States
TA  - J Neurophysiol
JT  - Journal of neurophysiology
JID - 0375404
SB  - IM
MH  - Adult
MH  - Afferent Pathways/physiology
MH  - Conditioning, Psychological
MH  - Female
MH  - Humans
MH  - Male
MH  - Median Nerve/*physiology
MH  - Motor Cortex/*physiology
MH  - Muscle Contraction
MH  - Muscle, Skeletal/innervation/physiology
MH  - *Neural Inhibition
MH  - *Reaction Time
MH  - Transcranial Magnetic Stimulation
OTO - NOTNLM
OT  - median nerve stimulation
OT  - paired-pulse inhibition
OT  - short afferent inhibition
OT  - short-interval intracortical inhibition
OT  - transcranial magnetic stimulation
EDAT- 2013/12/20 06:00
MHDA- 2014/11/08 06:00
CRDT- 2013/12/20 06:00
PHST- 2013/12/20 06:00 [entrez]
PHST- 2013/12/20 06:00 [pubmed]
PHST- 2014/11/08 06:00 [medline]
AID - jn.00613.2013 [pii]
AID - 10.1152/jn.00613.2013 [doi]
PST - ppublish
SO  - J Neurophysiol. 2014 Mar;111(6):1350-61. doi: 10.1152/jn.00613.2013. Epub 2013 
      Dec 18.