PMID- 12021815
OWN - NLM
STAT- MEDLINE
DCOM- 20020904
LR  - 20191210
IS  - 0014-4819 (Print)
IS  - 0014-4819 (Linking)
VI  - 144
IP  - 3
DP  - 2002 Jun
TI  - Reduced intracortical inhibition and facilitation of corticospinal neurons in 
      musicians.
PG  - 336-42
AB  - Interhemispheric inhibition between motor cortices is reduced in musicians. In 
      the present study we have assessed intracortical inhibition (ICI) and 
      facilitation (ICF) within ipsilateral motor cortex in 15 musicians and 15 
      non-musician controls. Transcranial magnetic stimulation (TMS) was used to elicit 
      muscle evoked potentials (MEPs) from left first dorsal interosseous (FDI) muscle 
      at rest, and during voluntary index finger abduction (0.5 N). Paired TMS with 
      subthreshold conditioning was used to test early ICI with interstimulus intervals 
      (ISIs) 1-5 ms, and ICF with ISIs 8-15 ms. Suprathreshold conditioning was used to 
      test late ICI with ISIs 100-200 ms. TMS thresholds were similar in musicians and 
      controls both at rest and with weak voluntary activation of FDI, indicating that 
      postsynaptic excitability of corticospinal neurons was similar in both groups. 
      ICI was less effective in musicians with FDI at rest and active, but only with an 
      ISI of 3 ms. ICF was less effective in musicians under both rest and active 
      conditions, and this was independent of ISI. There were no differences in late 
      ICI between musicians and controls. We conclude that ICI and ICF circuits which 
      are activated by weak TMS have less influence on corticospinal neuron 
      excitability in musicians. Because of the dependence on ISI, the most likely 
      explanation for the reduced ICI in musicians is an alteration of the interaction 
      between the ICI circuit and neural elements responsible for the later I-waves 
      evoked in corticospinal neurons by TMS. Excitability of the neural elements 
      producing early and late ICI is not altered in musicians. Reduced ICF in 
      musicians could be due to reduced excitability of neurons responsible for ICF, or 
      an altered balance of excitatory inputs to corticospinal neurons which favours 
      neurons that are not acted upon by the ICF circuit. The reduced influence of ICI 
      and ICF circuits on corticospinal neuron excitability in musicians is likely to 
      reflect a training-induced adaptation. It is not clear at present whether these 
      differences represent an adaptive change related to their extraordinary control 
      of finger movements, or alternatively a maladaptive change induced by "overuse" 
      of the hands from extensive training.
FAU - Nordstrom, Michael A
AU  - Nordstrom MA
AD  - Department of Physiology, University of Adelaide, Adelaide, SA 5005, Australia. 
      michael.nordstrom@adelaide.edu.au
FAU - Butler, Sophie L
AU  - Butler SL
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
DEP - 20020413
PL  - Germany
TA  - Exp Brain Res
JT  - Experimental brain research
JID - 0043312
SB  - IM
MH  - Adolescent
MH  - Adult
MH  - Conditioning, Psychological/physiology
MH  - Electric Stimulation
MH  - Evoked Potentials, Motor/physiology
MH  - Excitatory Postsynaptic Potentials/physiology
MH  - Female
MH  - Functional Laterality/physiology
MH  - Hand/innervation/physiology
MH  - Humans
MH  - Magnetics
MH  - Male
MH  - Motor Cortex/*physiology
MH  - Motor Neurons/*physiology
MH  - Motor Skills/physiology
MH  - Muscle Contraction/physiology
MH  - Muscle, Skeletal/innervation/physiology
MH  - *Music
MH  - Neural Inhibition/*physiology
MH  - Pyramidal Cells/physiology
MH  - Pyramidal Tracts/*physiology
MH  - Reaction Time/physiology
MH  - Spinal Cord/physiology
EDAT- 2002/05/22 10:00
MHDA- 2002/09/06 10:01
CRDT- 2002/05/22 10:00
PHST- 2001/08/21 00:00 [received]
PHST- 2002/01/31 00:00 [accepted]
PHST- 2002/05/22 10:00 [pubmed]
PHST- 2002/09/06 10:01 [medline]
PHST- 2002/05/22 10:00 [entrez]
AID - 10.1007/s00221-002-1051-7 [doi]
PST - ppublish
SO  - Exp Brain Res. 2002 Jun;144(3):336-42. doi: 10.1007/s00221-002-1051-7. Epub 2002 
      Apr 13.