Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
2000-9-15
pubmed:abstractText
In the adult rat, there is a general correspondence between the sizes of motoneurons, motor units, and muscle fibers that has particular functional importance in motor control. During early postnatal development, after the establishment of singular innervation, there is rapid growth of diaphragm muscle (Dia(m)) fibers. In the present study, the association between Dia(m) fiber growth and changes in phrenic motoneuron size (both somal and dendritic) was evaluated from postnatal day 21 (D21) to adulthood. Phrenic motoneurons were retrogradely labeled with fluorescent tetramethylrhodamine dextran (3,000 MW), and motoneuron somal volumes and surface areas were measured using three-dimensional confocal microscopy. In separate animals, phrenic motoneurons retrogradely labeled with choleratoxin B-fragment were visualized using immunocytochemistry, and dendritic arborization was analyzed by camera lucida. Between D21 and adulthood, Dia(m) fiber cross-sectional area increased by approximately 164% overall, with the growth of type II fibers being disproportionate to that of type I fibers. There was also substantial growth of phrenic motoneurons ( approximately 360% increase in total surface area), during this same period, that was primarily attributable to an expansion of dendritic surface area. Comparison of the distribution of phrenic motoneuron surface areas between D21 and adults suggests the establishment of a bimodal distribution that may have functional significance for motor unit recruitment in the adult rat.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
8750-7587
pubmed:author
pubmed:issnType
Print
pubmed:volume
89
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
563-72
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed:year
2000
pubmed:articleTitle
Phrenic motoneuron morphology during rapid diaphragm muscle growth.
pubmed:affiliation
Department of Anesthesiology, Mayo Foundation, Rochester, MN 55905, USA. prakash.ys@mayo.edu
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.