Linked Life Data

2750539

Source:http://linkedlifedata.com/resource/pubmed/id/2750539

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
1989-8-15
pubmed:abstractText
EMG recordings from single motor units in the soleus muscle were performed in alert unrestrained rats. A cuff electrode around the tibial nerve and subcutaneously placed electrodes in the foot permitted stimulation of afferent fibres. The movements of the rat and the simultaneous EMG activity were displayed together on a video monitor. Most motor units were tonically active for extended periods during quiet standing. During tonic discharge, maintained shifts between stable low (8-12 Hz; quartiles) and high (16-22.8 Hz) frequency ranges were initiated by short-lasting synaptic excitation of the motoneuron pool by stimulation of Ia afferents, or inhibition by stimulation of skin afferents. The shifts were not related to gross limb movements. This phenomenon is referred to as a bistable firing pattern. Bistable firing also occurred spontaneously during quiet standing. Typically the firing frequency shifted between a low (9-12.5 Hz) and a high (20-24.5 Hz) mode. During recordings of simultaneous activity in two units, spontaneous and stimulus-induced frequency jumps causing maintained changes in firing frequency were regularly seen to occur in one unit, while the frequency in the second unit was unchanged or only phasically influenced. These results demonstrate for the first time a bistable firing pattern during postural activity in the intact animal. The firing pattern closely resembles the bistable behaviour described in spinal motoneurons in reduced preparations, where it is due to the presence of a plateau potential. This suggests that the bistable firing is unexplained by plateau potentials also in the intact animal.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:status
MEDLINE
pubmed:month
Jul
pubmed:issn
0001-6772
pubmed:author
pubmed:issnType
Print
pubmed:volume
136
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
383-94
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1989
pubmed:articleTitle
Bistable firing properties of soleus motor units in unrestrained rats.
pubmed:affiliation
Department of Neurophysiology, University of Copenhagen, Denmark.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't