Linked Life Data

18292128

Source:http://linkedlifedata.com/resource/pubmed/id/18292128

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
8
pubmed:dateCreated
2008-4-16
pubmed:abstractText
The purpose of the study was to examine the influence of the difference between the recruitment threshold of a motor unit and the target force of the sustained contraction on the discharge of the motor unit at recruitment. The discharge characteristics of 53 motor units in biceps brachii were recorded after being recruited during a sustained contraction. Some motor units (n = 22) discharged action potentials tonically after being recruited, whereas others (n = 31) discharged intermittent trains of action potentials. The two groups of motor units were distinguished by the difference between the recruitment threshold of the motor unit and the target force for the sustained contraction: tonic, 5.9 +/- 2.5%; intermittent, 10.7 +/- 2.9%. Discharge rate for the tonic units decreased progressively (13.9 +/- 2.7 to 11.7 +/- 2.6 pulses s(-1); P = 0.04) during the 99 +/- 111 s contraction. Train rate, train duration and average discharge rate for the intermittent motor units did not change across 211 +/- 153 s of intermittent discharge. The initial discharge rate at recruitment during the sustained contraction was lower for the intermittent motor units (11.0 +/- 3.3 pulses s(-1)) than the tonic motor units (13.7 +/- 3.3 pulses s(-1); P = 0.005), and the coefficient of variation for interspike interval was higher for the intermittent motor units (34.6 +/- 12.3%) than the tonic motor units (21.2 +/- 9.4%) at recruitment (P = 0.001) and remained elevated for discharge duration (34.6 +/- 9.2% versus 19.1 +/- 11.7%, P < 0.001). In an additional experiment, 12 motor units were recorded at two different target forces below recruitment threshold (5.7 +/- 1.9% and 10.5 +/- 2.4%). Each motor unit exhibited the two discharge patterns (tonic and intermittent) as observed for the 53 motor units. The results suggest that newly recruited motor units with recruitment thresholds closer to the target force experienced less synaptic noise at the time of recruitment that resulted in them discharging action potentials at more regular and greater rates than motor units with recruitment thresholds further from the target force.
pubmed:grant
pubmed:commentsCorrections
http://linkedlifedata.com/resource/pubmed/commentcorrection/18292128-10530521, http://linkedlifedata.com/resource/pubmed/commentcorrection/18292128-11483719, http://linkedlifedata.com/resource/pubmed/commentcorrection/18292128-1159473, http://linkedlifedata.com/resource/pubmed/commentcorrection/18292128-11773336, http://linkedlifedata.com/resource/pubmed/commentcorrection/18292128-11929906, http://linkedlifedata.com/resource/pubmed/commentcorrection/18292128-12466432, http://linkedlifedata.com/resource/pubmed/commentcorrection/18292128-12522190, http://linkedlifedata.com/resource/pubmed/commentcorrection/18292128-14614080, http://linkedlifedata.com/resource/pubmed/commentcorrection/18292128-14615422, http://linkedlifedata.com/resource/pubmed/commentcorrection/18292128-14749290, http://linkedlifedata.com/resource/pubmed/commentcorrection/18292128-15483059, http://linkedlifedata.com/resource/pubmed/commentcorrection/18292128-15615827, http://linkedlifedata.com/resource/pubmed/commentcorrection/18292128-15736297, http://linkedlifedata.com/resource/pubmed/commentcorrection/18292128-15861181, http://linkedlifedata.com/resource/pubmed/commentcorrection/18292128-16036904, http://linkedlifedata.com/resource/pubmed/commentcorrection/18292128-16099677, http://linkedlifedata.com/resource/pubmed/commentcorrection/18292128-17195169, http://linkedlifedata.com/resource/pubmed/commentcorrection/18292128-17234950, http://linkedlifedata.com/resource/pubmed/commentcorrection/18292128-17294440, http://linkedlifedata.com/resource/pubmed/commentcorrection/18292128-17360826, http://linkedlifedata.com/resource/pubmed/commentcorrection/18292128-2600629, http://linkedlifedata.com/resource/pubmed/commentcorrection/18292128-2607432, http://linkedlifedata.com/resource/pubmed/commentcorrection/18292128-2920715, http://linkedlifedata.com/resource/pubmed/commentcorrection/18292128-3342852, http://linkedlifedata.com/resource/pubmed/commentcorrection/18292128-3745035, http://linkedlifedata.com/resource/pubmed/commentcorrection/18292128-3757896, http://linkedlifedata.com/resource/pubmed/commentcorrection/18292128-4112299, http://linkedlifedata.com/resource/pubmed/commentcorrection/18292128-4846331, http://linkedlifedata.com/resource/pubmed/commentcorrection/18292128-5709873, http://linkedlifedata.com/resource/pubmed/commentcorrection/18292128-6251180, http://linkedlifedata.com/resource/pubmed/commentcorrection/18292128-6284539, http://linkedlifedata.com/resource/pubmed/commentcorrection/18292128-6913469, http://linkedlifedata.com/resource/pubmed/commentcorrection/18292128-7279310, http://linkedlifedata.com/resource/pubmed/commentcorrection/18292128-7623081, http://linkedlifedata.com/resource/pubmed/commentcorrection/18292128-7928865, http://linkedlifedata.com/resource/pubmed/commentcorrection/18292128-845828, http://linkedlifedata.com/resource/pubmed/commentcorrection/18292128-9019553, http://linkedlifedata.com/resource/pubmed/commentcorrection/18292128-9547163, http://linkedlifedata.com/resource/pubmed/commentcorrection/18292128-9705452
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
1469-7793
pubmed:author
pubmed:issnType
Electronic
pubmed:day
15
pubmed:volume
586
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
2183-93
pubmed:dateRevised
2009-11-18
pubmed:meshHeading
pubmed:year
2008
pubmed:articleTitle
Motor unit recruitment in human biceps brachii during sustained voluntary contractions.
pubmed:affiliation
Department of Integrative Physiology, University of Colorado, Boulder, CO 80309-0354, USA. zachary.riley@colorado.edu
pubmed:publicationType
Journal Article, Research Support, N.I.H., Extramural