Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
2008-2-14
pubmed:abstractText
In some motoneurons, L-type Ca2+ channels that partly mediate persistent inward currents (PICs) have been estimated to be arranged in 50- to 200-microm-long discrete regions in the dendrites, centered 100 to 400 microm from the soma. As a consequence of this nonuniform distribution, the interaction between synaptic inputs to motoneurons and these channels may vary according to the distribution of the synapses. For instance, >93% of synapses from Renshaw cells have been observed to be located 65 to 470 microm away from the cell body of motoneurons. Our goal was to assess whether Renshaw cell synapses are distributed in a position to more effectively control the activation of the L-type Ca2+ channels. Using compartmental models of motoneurons with L-type Ca2+ channels distributed in 100-microm-long hot spots centered 100 to 400 microm away from the soma, we compared the inhibition generated by four distributions of inhibitory synapses: proximal, distal, uniform, and one based on the location of Renshaw cell synapses on motoneurons. Regardless of whether the synapses were activated tonically or transiently, in the presence of L-type Ca2+ channels, inhibitory synapses distributed according to the Renshaw cell synapse distribution generate the largest inhibitory currents. The effectiveness of a particular distribution of inhibitory synapses in the presence of PICs depends on their ability to deactivate the channels underlying PICs, which is influenced not only by the superposition between synapses and channels, but also by the distance away from the somatic voltage clamp.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Feb
pubmed:issn
0022-3077
pubmed:author
pubmed:issnType
Print
pubmed:volume
99
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
583-94
pubmed:dateRevised
2010-9-24
pubmed:meshHeading
pubmed:year
2008
pubmed:articleTitle
Relative location of inhibitory synapses and persistent inward currents determines the magnitude and mode of synaptic amplification in motoneurons.
pubmed:affiliation
Canadian Institutes of Health Research Group in Sensory-Motor Systems, Department of Physiology, Centre for Neuroscience Studies, Queen's University, Kingston, Canada.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't