Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
1978-7-15
pubmed:abstractText
In the small segmental tail muscles of the rat beta fibres provide exclusively the dynamic fusimotor control, while gamma fibres provide exclusively the static fusimor control. The present experiments were made to investigate the fusimotor innervation of spindles in a large muscle of the rat, the soleus, and thus to determine the occurrence and significance of beta innervation in this muscle. Our results have revealed no case of beta innervation in the rat soleus. As a consequence of our experimental method, however, we would not claim that beta innervation does not exist in the soleus, only that it must play an insignificant role relative to that seen in the tail segmental muscles. Investigations of the fusimotor innervation of eight spindles were sufficiently complete to warrant detailed illustration. The number of gamma fibres ranged from two to four. In every case the slowest conducting gamma fibre was dynamic. However, the conduction velocity spectra for the static and dynamic gamma fibres to rat soleus overlap to such an extent that it is impossible to use conduction velocity as the sole guide to functional gamma fibre classification. The pooled results from the eight spindles fully investigated provide a ratio of static to dynamic gamma fibres of approximately 1:1. Other evidence discussed in the paper suggests that in the muscle nerve the ratio is considerably higher. These differences are reconciled if the dynamic gamma fibres branch more profusely and innervate more spindles than do the static gamma fibres.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
0014-4819
pubmed:author
pubmed:issnType
Print
pubmed:day
15
pubmed:volume
31
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
433-43
pubmed:dateRevised
2009-11-11
pubmed:meshHeading
pubmed:year
1978
pubmed:articleTitle
Some observations on the efferent innervation of rat soleus muscle spindles.
pubmed:publicationType
Journal Article