Linked Life Data

3514815

Source:http://linkedlifedata.com/resource/pubmed/id/3514815

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
1986-5-9
pubmed:abstractText
Experiments were conducted to test the hypothesis that a partitioning of Ia monosynaptic excitatory postsynaptic potentials (Ia EPSPs) is present in motor nuclei supplying muscles with regions capable of different mechanical actions. Intracellular recordings of synaptic potentials were made in lateral gastrocnemius (LG) motoneurons in anesthetized low-spinal cats. The effects were tested of stimuli (group I range) to the four primary nerve branches of the LG nerve supplying muscle compartments LGm, LG1, LG2, and LG3 (terminology of English, Ref. 26) and the nerve to a heteronymous muscle, soleus. Stimulation of a given LG nerve branch produced monosynaptic Ia EPSPs of greater amplitude in "own-branch" motoneurons than "other-branch" cells. A significant partitioning of mean Ia EPSPs was found in three (LG1, LG2, LG3) out of the four homonymous pathways studied. An EPSP normalization (7) was performed to eliminate potential differences in cell type that might affect the amplitudes of the EPSPs between these four cell groups (e.g., differences in the number of cells supplying FF, FR, and S muscle units). This normalization confirmed that the partitioning of monosynaptic Ia inputs upon stimulation of LG1, LG2, and LG3 could not be attributed to differences in cell type. In addition, the effects of LGm stimulation were found to be significantly greater in the LGm motoneurons compared with the other cell groups. Heteronymous input (from soleus) to the LG motor nucleus showed some partitioned effects. Motoneurons innervating compartment LG2 received larger EPSPs from soleus than did the cells supplying compartments LG1, LG3, and LGm. The contributions of location specificity and species specificity (terminology of Scott and Mendell, Ref. 55) in the establishment of these Ia-afferent-motoneuronal connections were examined. Cell location sites within the spinal cord were consistent with location specificity making some contribution to the observed pattern of homonymous Ia connections. A more prominent role for species specificity was indicated by species-dependent differences in EPSP amplitude in pairs of LG motoneurons (e.g., LGm vs. LG2) at similar rostrocaudal locations upon stimulation of a given homonymous or heteronymous nerve/branch.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
0022-3077
pubmed:author
pubmed:issnType
Print
pubmed:volume
55
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
569-86
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1986
pubmed:articleTitle
Partitioning of monosynaptic Ia excitatory postsynaptic potentials in the motor nucleus of the cat lateral gastrocnemius muscle.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Review, Research Support, Non-U.S. Gov't