PMID- 16253557
OWN - NLM
STAT- MEDLINE
DCOM- 20060131
LR  - 20080910
IS  - 1388-2457 (Print)
IS  - 1388-2457 (Linking)
VI  - 116
IP  - 12
DP  - 2005 Dec
TI  - Differential modulations of intracortical neural circuits between two intrinsic 
      hand muscles.
PG  - 2757-64
AB  - OBJECTIVE: To investigate whether the intracortical inhibitory (ICI) and 
      facilitatory (ICF) circuits in the primary motor cortex between the first dorsal 
      interosseous (FDI) and abductor digiti minimi (ADM) muscles are modulated 
      differently. METHODS: We conducted paired-pulse transcranial magnetic stimulation 
      in combination with different current directions (anterior-medially: AM, and 
      posterior-laterally: PL) under relaxed and active muscle conditions with 
      interstimulus intervals (ISIs) between 2 and 16 ms. RESULTS: In both muscle 
      conditions, the conditioned motor-evoked potential (MEP) responses obtained with 
      the AM current direction (preferentially eliciting early I-waves) were similar 
      between the two muscles at all ISIs, but the MEP responses obtained with the PL 
      current direction (preferentially eliciting late I-waves) were different between 
      FDI and ADM muscles, in that the conditioned MEP responses in FDI muscle were 
      inhibited at all ISIs under both muscle conditions, whereas those in ADM muscle 
      were suppressed at only short ISIs (2-4 ms). CONCLUSIONS: These results indicate 
      that the inhibitory connections operating for the corticospinal tract neurons in 
      FDI muscle are more potent, and, conversely, that those in ADM muscle are weaker. 
      SIGNIFICANCE: The different modulations of ICI circuits between FDI and ADM 
      muscles is an important neural mechanism which may contribute to different 
      functional demands (finger dexterity).
FAU - Takahashi, Makoto
AU  - Takahashi M
AD  - Division of Sports and Health Sciences, Graduate School for International 
      Development and Cooperation, Hiroshima University, Higashihiroshima, Japan.
FAU - Ni, Zhen
AU  - Ni Z
FAU - Yamashita, Takamasa
AU  - Yamashita T
FAU - Liang, Nan
AU  - Liang N
FAU - Sugawara, Kenichi
AU  - Sugawara K
FAU - Yahagi, Susumu
AU  - Yahagi S
FAU - Kasai, Tatsuya
AU  - Kasai T
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
DEP - 20051025
PL  - Netherlands
TA  - Clin Neurophysiol
JT  - Clinical neurophysiology : official journal of the International Federation of 
      Clinical Neurophysiology
JID - 100883319
SB  - IM
MH  - Adult
MH  - Electromyography
MH  - Female
MH  - Fingers/*innervation/physiology
MH  - Humans
MH  - Male
MH  - Motor Cortex/*physiology
MH  - Movement/*physiology
MH  - Muscle Contraction/physiology
MH  - Muscle Relaxation/physiology
MH  - Muscle, Skeletal/*innervation/physiology
MH  - Reaction Time/physiology
EDAT- 2005/10/29 09:00
MHDA- 2006/02/01 09:00
CRDT- 2005/10/29 09:00
PHST- 2005/04/12 00:00 [received]
PHST- 2005/08/11 00:00 [revised]
PHST- 2005/08/17 00:00 [accepted]
PHST- 2005/10/29 09:00 [pubmed]
PHST- 2006/02/01 09:00 [medline]
PHST- 2005/10/29 09:00 [entrez]
AID - S1388-2457(05)00361-5 [pii]
AID - 10.1016/j.clinph.2005.08.024 [doi]
PST - ppublish
SO  - Clin Neurophysiol. 2005 Dec;116(12):2757-64. doi: 10.1016/j.clinph.2005.08.024. 
      Epub 2005 Oct 25.