Linked Life Data

7472383

Source:http://linkedlifedata.com/resource/pubmed/id/7472383

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1995-12-7
pubmed:abstractText
1. We used a modified voltage-clamp technique to measure the steady-state effective synaptic currents (I(N)) produced by activating four different input systems to cat hindlimb motoneurons: Ia afferent fibers, Ia-inhibitory interneurons, Renshaw interneurons, and contralateral rubrospinal neurons. In the same motoneurons, we measured the slope of the firing rate-injected current (f-I) relation in the primary range. We then reactivated these synaptic inputs during steady, repetitive firing to assess their effects on motoneuron discharge rate. 2. Our measurements of I(N) were derived from recordings made near the resting membrane potential, whereas the effects of the synaptic inputs on repetitive discharge were evaluated at more depolarized membrane potentials. Thus we adjusted the I(N) values for these changes in driving force based on estimates of the synaptic reversal potential and the mean membrane potential during repetitive discharge. 3. We found that changes in the steady-state discharge rate of a motoneuron produced by these synaptic inputs could be reasonably well predicted by the product of the estimated value of I(N) during repetitive firing and the slope of the motoneuron's f-I relation. Although there was a high correlation between predicted and observed changes in firing rate for our entire sample of motoneurons (r = 0.93; P < 0.001), the slope of the relation between predicted and observed firing rate modulation was significantly greater than 1. 4. The systematic difference between predicted and observed firing rate modulation observed in the overall sample was primarily due to the fact that our predictions underestimated the changes in firing rate produced by Ia excitation and Ia inhibition.(ABSTRACT TRUNCATED AT 250 WORDS)
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
0022-3077
pubmed:author
pubmed:issnType
Print
pubmed:volume
74
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
793-801
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1995
pubmed:articleTitle
Effective synaptic current and motoneuron firing rate modulation.
pubmed:affiliation
Department of Physiology and Biophysics, University of Washington, School of Medicine, Seattle 98195, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.