Linked Life Data

7056320

Source:http://linkedlifedata.com/resource/pubmed/id/7056320

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1-2
pubmed:dateCreated
1982-4-12
pubmed:abstractText
We examined the characteristics of postsynaptic potentials (PSPs) produced in antidromically-identified medical gastrocnemius (MG) alpha-motoneurons by electrical stimulation of low threshold (less than 3 x T) distal limb cutaneous afferents in the sural (SUR) nerve in adult cats anesthetized with alpha-chloralose, together with the effects of SUR PSPs of supraspinal conditioning stimulation of the contralateral red nucleus (RN) and pyramidal tract (PT). In the majority of MG motoneurons, SUR afferents with electrical thresholds less than 1.5 x T produced early excitatory synaptic potentials (EPSPs) with minimum central latency of about 2.0 ms, suggesting activation of a trisynaptic segmental pathway with two interposed interneurons. Such early EPSPs were often detectable with stimuli less than 1.2 x T, as determined by recording the compound action potential in the sciatic nerve and from the first appearance of the N1 wave of the cord dorsum potential. Inhibitory synaptic potentials (IPSPs) were regularly produced by SUR volleys of only slightly greater strength (often as low as 1.3 x T) and these had minimum central latencies of about 3.0 ms (about 1.0 ms longer than the earliest EPSPs), suggesting a three interneuron central pathway. Repetitive stimulation of RN and PT regularly produced facilitation of both EPSP and IPSP components in the SUR response, suggesting that these supraspinal systems directly or indirectly excite some of the same interneurons that convey the SUR effects to MG motoneurons. When using very low strength SUR stimuli, PT conditioning produced relatively pure facilitation of the SUR EPSPs but with larger SUr volleys, PT clearly facilitated both EPSPs and IPSPs. RN conditioning produced more parallel facilitation of SUR EPSPs and IPSPs. Supraspinal control of the polysynaptic pathway producing SUR EPSPs is of particular interest because of earlier evidence that this pathway is differentially distributed to motoneurons of fast twitch versus slow twitch MG motor units.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:status
MEDLINE
pubmed:issn
0014-4819
pubmed:author
pubmed:issnType
Print
pubmed:volume
45
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
133-43
pubmed:dateRevised
2009-11-11
pubmed:meshHeading
pubmed:year
1982
pubmed:articleTitle
Supraspinal facilitation of cutaneous polysynaptic EPSPs in cat medical gastrocnemius motoneurons.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't