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Finger movement is associated with attenuated cutaneous reflexes recorded from human first dorsal interosseous muscle
Author(s) -
Turner L. C.,
Harrison L. M.,
Stephens J. A.
Publication year - 2002
Publication title -
the journal of physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.802
H-Index - 240
eISSN - 1469-7793
pISSN - 0022-3751
DOI - 10.1113/jphysiol.2002.023846
Subject(s) - index finger , middle finger , thumb , somatosensory system , anatomy , somatosensory evoked potential , medicine , little finger , dorsum , reflex , finger tapping , sensory system , median nerve , tapping , neuroscience , audiology , anesthesia , psychology , management , psychiatry , economics
Cutaneomuscular reflexes (CMR) have been recorded from the first dorsal interosseous muscle (1DI) of the preferred hand, somatosensory evoked potentials (SEP) were recorded from the contralateral sensory cortex and the sensory nerve action potential (SNAP) was recorded from the median nerve of 15 adult subjects whilst electrically stimulating the digital nerves of the index finger. Subjects performed the following tasks (a) a sustained abduction of the index finger against resistance at 10–20 % maximum voluntary contraction (MVC), and (b) abduction of the index finger as in (a) whilst performing self paced low amplitude tapping of the (i) index finger, (ii) thumb, (iii) middle finger, (iv) little finger and (v) ipsilateral foot. The E2 component of the CMR and the N20/P25 components of the SEP were significantly reduced during finger tapping ( P < 0.05). This reduction was independent of which finger was tapping ( P > 0.05). There was a significant (qualitative) relationship between the decrease in the size of the E2 component of the CMR and the N20/P25 components of the SEP (χ 2 test; P < 0.05). There were no significant changes in E1 and I1 ( P > 0.05). The size of the SNAP was independent of task ( P > 0.05). The size of the E1, I1, E2 components of the CMR, and the N20/P25 components of the SEP were unaltered during foot tapping ( P > 0.05, n = 4). We conclude that the decrease in size of the E2 component associated with finger tapping results from gating of the digital nerve input.