Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
6
pubmed:dateCreated
1985-7-30
pubmed:abstractText
Locomotion consists of a repeating series of movement cycles (locomotor rhythm) with an orderly activation of musculature during each movement cycle (intracycle motor pattern). The effects of sensory stimulation, on both the intracycle motor pattern and the locomotor rhythm, were examined during electrically elicited swimming movements of a single turtle hindlimb. The resulting "monopodal" swimming was not subject to movement-related reflexes from other limbs or postural constraints, and provided a sensitive system for analyzing the effects of transient sensory perturbations. During "monopodal" swimming, cutaneous and extensor muscle-nerve stimulation (single 0.1- to 0.3-msec electrical pulse) had similar phase-dependent effects on the swim cycle in progress. Stimuli delivered during the powerstroke (limb retracting) shortened the period of the cycle. Stimulation during the returnstroke prolonged the cycle. Changes in cycle period were accompanied by in-phase adjustments of the EMG burst duration or interburst interval which was being expressed at the time of stimulus delivery. The in-phase adjustment of each muscle served to maintain the timing relationships between muscles, and resulted in the preservation of the intracycle motor pattern. Cutaneous and muscle-nerve stimulation had dramatically different effects on the locomotor rhythm. Cutaneous nerve stimulation produced period changes in poststimulus cycles which led to a temporary phase shift of the swimming rhythm. This temporary modulation suggests that cutaneous afferents do not have direct access to the timing circuitry of the central nervous system locomotor network. Muscle-nerve stimulation only altered the period of the cycle in progress at the time of stimulus delivery, and thus permanently reset the locomotor rhythm. This permanent phase shift suggests that muscle afferents have direct access to a central timing network which controls the locomotor rhythm.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
0270-6474
pubmed:author
pubmed:issnType
Print
pubmed:volume
5
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1434-45
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed:year
1985
pubmed:articleTitle
Afferent perturbations during "monopodal" swimming movements in the turtle: phase-dependent cutaneous modulation and proprioceptive resetting of the locomotor rhythm.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.