PMID- 16078031
OWN - NLM
STAT- MEDLINE
DCOM- 20060329
LR  - 20181113
IS  - 0014-4819 (Print)
IS  - 0014-4819 (Linking)
VI  - 167
IP  - 3
DP  - 2005 Dec
TI  - Sensorimotor integration to cutaneous afferents in humans: the effect of the size 
      of the receptive field.
PG  - 362-9
AB  - Transcranial magnetic stimulation (TMS) can be used to study sensorimotor 
      integration in humans non-invasively. Motor excitability has been found to be 
      inhibited when afferent stimuli are given to a peripheral nerve and precede TMS 
      at interstimulus intervals (ISIs) of 20-50 ms. This phenomenon has been referred 
      to as short-latency afferent inhibition (SAI). To better understand the 
      functional meaning of these phenomena, we examined the effect of the size of the 
      receptive field on SAI to cutaneous afferents in upper-limb sensorimotor areas in 
      humans. We examined the effect of the stimulation of the isolated right first 
      (D1), second (D2) and third finger (D3), the right second and third finger 
      together (D23) and the right first three fingers together (D123) on the amplitude 
      of motor evoked potentials (MEPs) to TMS in hand and forearm muscles. We examined 
      the right abductor pollicis brevis (APB), first dorsal interosseous (FDI), 
      extensor carpi radialis (ECR) and flexor carpi radialis (FCR) muscles. Digital 
      stimulation preceded TMS at ISIs of 20-50 ms. The effect of D2 stimulation was 
      MEP inhibition (SAI), which was more marked and consistent in APB and FDI muscles 
      than in ECR and FCR muscles. Similarly, D1 and D3 stimulation caused MEP 
      reduction, while no MEP enhancement could be found to single finger stimulation. 
      In contrast, D123 stimulation induced less effective SAI in upper-limb muscles. 
      MEP potentiation was recorded in some muscles to D123 stimulation. A significant 
      difference between D2 and D123 stimulation was found in APB (ISIs = 30-50 ms) and 
      FDI (ISIs = 40-50 ms) muscles, but not in forearm muscles. The effect to 
      D23stimulation on MEP amplitude was intermediate between those to D2 and D123 
      stimulation. Our data suggest that motor excitability to cutaneous afferents may 
      be influenced by the size of the receptive fields, this effect being the result 
      of increasing convergence between hand afferents in the somatosensory system. 
      These phenomena appear to be topographically arranged across the representation 
      of upper-limb muscles. These findings may help to understand the functional 
      significance of SAI in normal physiology and pathophysiology.
FAU - Tamburin, Stefano
AU  - Tamburin S
AD  - Department of Neurological Sciences and Vision, Section of Neurological 
      Rehabilitation, University of Verona, Verona, Italy. s_tamburin@yahoo.com
FAU - Fiaschi, Antonio
AU  - Fiaschi A
FAU - Andreoli, Annalisa
AU  - Andreoli A
FAU - Marani, Silvia
AU  - Marani S
FAU - Zanette, Giampietro
AU  - Zanette G
LA  - eng
PT  - Clinical Trial
PT  - Journal Article
DEP - 20050803
PL  - Germany
TA  - Exp Brain Res
JT  - Experimental brain research
JID - 0043312
SB  - IM
MH  - Adult
MH  - Electric Stimulation
MH  - Evoked Potentials, Motor/physiology
MH  - Female
MH  - Fingers/physiology
MH  - Forearm/innervation/physiology
MH  - Hand/innervation/physiology
MH  - Humans
MH  - Male
MH  - Median Nerve/physiology
MH  - Muscle, Skeletal/innervation/physiology
MH  - Neurons, Afferent/*physiology
MH  - Psychomotor Performance/*physiology
MH  - Sensory Thresholds/physiology
MH  - Skin/*innervation
MH  - Touch/*physiology
MH  - Transcranial Magnetic Stimulation
EDAT- 2005/08/04 09:00
MHDA- 2006/03/30 09:00
CRDT- 2005/08/04 09:00
PHST- 2005/01/12 00:00 [received]
PHST- 2005/04/26 00:00 [accepted]
PHST- 2005/08/04 09:00 [pubmed]
PHST- 2006/03/30 09:00 [medline]
PHST- 2005/08/04 09:00 [entrez]
AID - 10.1007/s00221-005-0041-y [doi]
PST - ppublish
SO  - Exp Brain Res. 2005 Dec;167(3):362-9. doi: 10.1007/s00221-005-0041-y. Epub 2005 
      Aug 3.